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HomeMy WebLinkAboutCDP 15-25; YUKI LANE; UPDATED GEOTECHNICAL RECOMMENDATIONS, LOTS 1 & 2; 2015-09-05ENGINEERING DESIGN GROUP I iU' c1uIi;5 CO'LCIL 2121 Montiel Road, San Marcos, California 92069• (760) 839-7302. Fax: (760) 480-7477 www.designgroupca.com UPDATED GEO TECHNICAL RECOMMENDATIONS PROPOSED NEW SINGLE FAMILY RESIDENCE TO BE LOCATED AT LOT 2, YUKI LANE CARLSBAD, CALIFORNIA EDG Project No. 155513-1 September 3, 2015 PREPARED FOR: Pacific Beach 2014, Ltd. do San Dieguito Development Attn: Ted Montag 1106 Second St PMB 255 Encinitas, CA 92024 p: 760.635.7633 AUG 2 6 2016 LAND DEVELOPMENT ENGINEERING ENGINEERING DESIGN GROUP GEOCNICACrJL. STRUC UFS S HJTFCIURS 5555511455$ FOR SlOSH t&COMM$HCOR C55UCORN 2121 Montiel Road, San Marcos, California 92069. (760) 839-7302 Fax: (760) 480-7477 www.designgroupca.com N. — ,••.• ..-'*,. ..•._, •d*_#J%d%J.d •J%.#4_ #'VVIYVT.tJCOp9JI9SUU1Jt,Q.(.%JIPI Date: September 3, 2015 To: Pacific Beach 2014, Ltd. do San Dieguito Development Attn: Ted Montag 1106 Second St PMB 255 Encinitas, CA 92024 p: 760.635.7633 e: tedmontaq3msn.com Re: Proposed new residence to be located at Lot 2 Yuki Lane, Carlsbad, California Subject: Updated Geotechnical Report We have provided the following updated limited geotechnical report for the proposed new residence at the above referenced address. Earthwork recommendations and foundation design parameters are presented in this report. In general it is our opinion that the proposed construction, as described herein, is feasible from a geotechnical standpoint, provided the recommendations of this report and generally accepted construction practices are followed. If you have any questions regarding the following report please do not hesitate to contact our office. Sincerely, ENGINEERING DESIGN GROUP 1~ \*dl Erin E. Rist California RCE #65122 E. C 65122 Steven Norris California GE#2590 Table of Contents 1.0 SCOPE .1 2.0 SITE AND PROJECT DESCRIPTION ..............................................................................1 3.0 FIELD INVESTIGATION ................................................. ................................................... 1 40 SUBSURFACE CONDITIONS I 5.0 GROUNDWATER ..........................................................................................................1 6.0 LIQUEFACTION .............................................................. ................................................ 2 7.0 CONCLUSIONS AND RECOMMENDATIONS . ..............................................................3 7.1 GENERAL ......................................................................................................................3 7.2 EARTHWORK ...............................................................................................................3 7.3 FOUNDATIONS ................................................. . .......................................................... 4 7.4 CONCRETE SLABS ON GRADE .................................................................................6 7.5 RETAINING WALLS ....................................................................................................8 8.0 SURFACE DRAINAGE .................................................................................................... 11 9.0 CONSTRUCTION OBSERVATION AND TESTING .......................................................11 10.0 MISCELLANEOUS ............................................................. ....... . .................................... 12 APPENDICES References..................................................................................................................Appendix A General Earthwork and Grading Specifications ........ ............................ . ...................... Appendix B Retaining Wall Drainage Detail ..................................................................................Appendix C 1.0 SCOPE This report gives our recommendations for the proposed new residence to be constructed on Lot 2, Yuki Lane, Carlsbad, California. The scope of our work conducted onsite to date has included a visual reconnaissance of the property and surrounding areas, review of past reports, and preparation of this report presenting our findings, conclusions and recommendations. 2.0 SITE AND PROJECT DESCRIPTION The subject property consists of a graded building pad bordered to the south by single family dwellings, to the north and east by a vacant un-developed lots and to the west by Yuki Lane. The general topography of the site area consists of coastal foothill terrain. The site consists of a relatively flat building pad flanked to the north by ascending 2:1 graded slope to the lot above, to the south and west by graded descending slopes. At the time of this report the property is generally undeveloped. The building pad was graded in and around summer-fall 2014. We understand the proposed new development will consist of a new two story single family residence. 3.0 FIELD INVESTIGATION No additional subsurface investigation was conducted as part of the proposed scope of work. Grading of the subject site occurred in 2014. Engineering Design Group provided limited observation and testing during the grading of the building pads. Based upon our limited earthwork observation and testing conducted at the time of site grading fills on the order of 3-11 feet should be anticipated in the area of the proposed building pad. Fill materials general classify as SW-SM according to the Unified Soil Classification System, and based on visual observation, are considered to possess low potential for expansion. 5.0 GROUND WATER Groundwater was not encountered in during the grading of the subject property. Groundwater is not anticipated to pose a significant constraint to construction, however based upon our experience, perched groundwater conditions can develop where no such condition previously existed. Perched groundwater conditions can develop over time and can have a significant Yuki Lane Development Page No. 1 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS t impact, especially at basements. Waterproofing membrane shall be specifically detailed by waterproofing consultant. If groundwater conditions are encountered during site excavations, a slab underdrain system may be required. Any proposed bioretention facilities within close proximity of the residence shall be lined with an impervious waterproof barrier. Proper surface drainage and irrigation practices will play a significant role in the future performance of the project. Please note in the "Concrete Slab on Grade" section of this report for specific recommendations regarding water to cement ratio for moisture sensitive areas should be adhered. The project architect and/or waterproofing consultant shall specifically address waterproofing details. It is our opinion that the site could be subjected to moderate to severe ground shaking in the event of a major earthquake along any of the faults in the Southern California region. However, the seismic risk at this site is not significantly greater than that of the surrounding developed area. Liquefaction of cohesionless soils can be caused by strong vibratory motion due to earthquakes. Research and historical data indicate that loose, granular soils underlain by a near-surface ground water table are most susceptible to liquefaction, while the stability of most silty sands and clays is not adversely affected by vibratory motion. Because of the dense nature of the soil materials underlying the site and the lack of near surface water, the potential for liquefaction or seismically-induced dynamic settlement at the site is considered low. The effects of seismic shaking can be reduced by adhering to the most recent edition of the Uniform Building Code and current design parameters of the Structural Engineers Association of California. Yuki Lane Development Page No. 2 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGLVEERING DESIGN GROVP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 7.0 CONCLUSIONS AND RECOMMENDATIONS 7.1 GENERAL In general it is our opinion that the proposed new residence, as discussed and described herein, is feasible from a geotechnical standpoint, provided the recommendations of this report and all applicable codes are followed. 7.2 EARTHWORK We anticipate site grading will be limited to a shallow rip and recompact of the upper 8 inches in the area of the proposed building pad and backfill behind proposed new retaining walls and utility trenches. All grading should be done in accordance with the recommendations below as well as the standards of county and state agencies, as applicable. 7.2.a. Site Preparation Prior to any grading, the areas of proposed improvements should be cleared of surface and subsurface debris (including organic topsoil, vegetative and construction debris). Removed debris should be properly disposed of off-site prior to the commencement of any fill operations. Holes resulting from the removal of debris, existing structures, or other improvements which extend below the undercut depths noted, should be filled and compacted. 7.2.b. Removals The area of the proposed new building and settlement sensitive improvements shall be scarified with a shallow rip, approximately 8 inches, moisture conditioned and the recompacted to 90 percent minimum relative compaction. 7.2.c. Transitions All settlement sensitive improvements should be constructed on a uniform building pad. The building pad area was undercut during original grading to an approximate depth of 3-4 feet. Where new footing excavations extend beyond the area of undercut footings may require overexcavation and recompaction to a minimum of one foot below the bottom of the footing, as determined by the geotechnical engineer at the time of construction. Yuki Lane Development Page No. 3 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERiNG DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 7.2.d. Fills All new fill and backfill should be brought to approximately +2% of optimum moisture content and re-compacted to at least 90 percent relative compaction (based on ASTM D1557). Compacted fills should be cleaned of loose debris and oversize material in excess of 6 inches in diameter, brought to near optimum moisture content, and re-compacted as described above. Fills should generally be placed in lifts not exceeding 6-8 inches in thickness. Import of soil material is not anticipated, however if import material is required, soils should have a very low potential for expansion (Ek20), free of debris and organic matter. Prior to importing soils, they should be visually observed, sampled and tested at the borrow pit area to evaluate soil suitability as fill. 7.2.e. Slopes Where new slopes are constructed permanent slopes may be cut to a face ratio of 2:1 (horizontal to vertical). Permanent fill slopes shall be placed at a maximum 2:1 slope face ratio. All temporary cut slopes shall be excavated in accordance with OSHA requirements and shall not undermine adjacent property or structures without proper shoring of excavation and/or structures. Subsequent to grading, planting or other acceptable cover should be provided to increase the stability of slopes, especially during the rainy season (October thru April). Contractor shall take all necessary precautions to protect improvements at the street during anticipated excavations. 7.3 FOUNDATIONS The following design parameters may be utilized for new foundations founded on competent material. 7.3.a. Footings bearing into competent sandstone or recompacted fill material may be designed utilizing maximum allowable soils pressure of 2,000 psf. 7.3.b. Seismic Design Parameters 2013 CBC Site Class D Spectral Response Coefficients Yuki Lane Development Page No. 4 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGiNEERING DFSIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS SMS (g) 1.183 SMI (g) 0.679 SOS (g) 0.789 SDI (g) 0.453 7.3.c. Bearing values may be increased by 33% when considering wind, seismic, or other short duration loadings. 7.3.d. The parameters in the table below should be used as a minimum for designing new footing width and depth below lowest adjacent grade into recompacted fill material. Footing depths are to be confirmed in the field by a representative of Engineering Design Group prior to the placement of form boards, steel and removal of excavation equipment. No. of Floors Supported Minimum Footing Width *Minimum Footing Depth Below Lowest Adjacent Grade 1 15 inches 18 inches 2 15inches 18 inches 3 18 inches 24 inches 7.3.e. All footings founded into competent material should be reinforced with a minimum of two #4 bars at the top and two #4 bars at the bottom (3 inches above the ground). For footings over 30 inches in depth, additional reinforcement, and possibly a stemwall system will be necessary, and should be reviewed by project structural engineer prior to construction. 7.3.f. All isolated spread footings should be designed utilizing the above given bearing values and footing depths, and be reinforced with a minimum of #4 bars at 12 inches o.c. in each direction (3 inches above the ground). Isolated spread footings should have a minimum width and depth of 24 inches. 7.3.g. For footings adjacent to slopes a minimum of 10 feet (competent, compacted material) Yuki Lane Development Page No. 5 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEEPJNG DFSIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS and horizontal setback in competent material or properly compacted fill should be maintained. A setback measurement should be taken at the horizontal distance from the bottom of the footing to slope daylight. Where this condition cannot be met it should be brought to the attention of the Engineering Design Group for review. 7.3.h. All excavations should be performed in general accordance with the contents of this report, applicable codes, OSHA requirements and applicable city and/or county standards. 7.3.i. All foundation subgrade soils and footings shall be pre-moistened to 2% over optimum to a minimum of 18 inches in depth prior to the pouring of concrete. 7.4 CONCRETE SLABS ON GRADE We recommend the following as the minimum design parameters for new concrete slabs on grade. 7.4.a. Concrete slab on grade of the proposed building and driveway should have a minimum thickness of 5 inches and should be reinforced with #4 bars at 18 inches o.c. placed at the midpoint of the slab. 7.4.a.i Slump: Between 3 and 4 inches maximum 7.4.a.ii Aggregate Size: 3/4 - 1 inch 7.4.a.iii Moisture Sensitive Areas: At concrete slab on grade floors in moisture sensitive area (i.e. floors, below grade walls) we recommend a maximum water to cement Ratio - 0.45 maximum Compressive Strength = 4,500 psi minimum (No special inspection required for water to cement ratio purposes, unless otherwise specified by the structural engineer). This recommendation is intended to achieve a low permeability concrete. 7.4.a.iv Moisture retarding additive: in concrete at concrete slab on grade floors and moisture sensitive area 7.4.a.v Corrosion Potential: Based upon laboratory testing conducted as part of the field investigation onsite soils meet ACI exposure categories SO, Cl. The project structural engineer to note increased concrete protection requirements for corrosive environments, as applicable. EDG is not an expert in corrosion or corrosion prevention. All corrosion recommendations Yuki Lane Development Page No. 6 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS shall be provided by the corrosion consultant. 7.4.a.vi Non-Moisture Sensitive Areas: Compressive Strength = 2,500 psi minimum. 7.4.b. In areas of level slab on grade floors we recommend a one inch layer of coarse sand material, Sand Equivalent (S.E.) greater than 50 and washed clean of fine materials, should be placed beneath the slab in moisture sensitive areas, above the vapor barrier. There shall be not greater than an ½ inch difference across the sand layer. 7.4.c. In moisture sensitive areas, a vapor barrier layer (15 mil) should be placed below the upper one inch of sand. The vapor barrier shall meet the following minimum requirements: Permeance of less than 0.01 perm [grains/(ft2 hr in/Hg)] as tested in accordance with ASTM E 1745 Section 7.1. Strength per ASTM 1745 Class A. The vapor barrier should extend down the interior edge of the footing excavation a minimum of 6 inches. The vapor barrier should lap a minimum of 8 inches, sealed along all laps with the manufacturer's recommended adhesive. Beneath the vapor barrier a uniform layer of 3 inches of pea gravel is recommended under the slab in order to more uniformly support the slab, help distribute loads to the soils beneath the slab, and act as a capillary break. 7.4.d. The project waterproofing consultant should provide all slab underdrain, slab sealers and various other details, specifications and recommendations (i.e Moiststop and Linkseal) at areas of potential moisture intrusion (i.e. slab penetrations). Engineering Design Group accepts no responsibility for design or quality control of waterproofing elements of the building. 7.4.e. Adequate control joints should be installed to control the unavoidable cracking of concrete that takes place when undergoing its natural shrinkage during curing. The control joints should be well located to direct unavoidable slab cracking to areas that are desirable by the designer. 7.4.f. Any additional fills used to support slabs, should be placed in accordance with the grading section of this report, Section 7. 1, and compacted to 90 percent Modified Proctor Density, ASTM D-1557, and as described in the Earthwork section of this report. 7.4.g. All subgrade soils to receive concrete slabs and flatwork are to be pre-soaked to 2 percent over optimum moisture content to a depth of 18 inches. Yuki Lane Development Page No. 7 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 7.4.h. Exterior concrete flatwork, due to the nature of concrete hydration and minor subgrade soil movement, are subject to normal minor concrete cracking. To minimize expected concrete cracking, the following may be implemented: Concrete may be poured with a 10 inch deep thickened edge. Flatwork adjacent to top of a slope should be constructed with an outside footing to attain a minimum of 7 feet distance to daylight. Concrete slump should not exceed 4 inches. Concrete should be poured during "cool" (40 - 65 degrees) weather if possible. If concrete is poured in hotter weather, a set retarding additive should be included in the mix, and the slump kept to a minimum. Concrete subgrade should be pre-soaked prior to the pouring of concrete. The level of pre-soaking should be a minimum of 2% over optimum moisture to a depth of 18 inches. Concrete should be constructed with tooled joints creating concrete sections no larger than 225 square feet. For sidewalks, the maximum run between joints should not exceed 5 feet. For rectangular shapes of concrete, the ratio of length to width should generally not exceed 0.6 (i.e., 5 ft. long by 3 ft. wide). Joints should be cut at expected points of concrete shrinkage (such as male corners), with diagonal reinforcement placed in accordance with industry standards. Isolation joints should be installed at exterior concrete where exterior concrete is poured adjacent to existing foundations. Drainage adjacent to concrete flatwork should direct water away from the improvement. Concrete subgrade should be sloped and directed to the collective drainage system, such that water is not trapped below the flatwork. The recommendations set forth herein are intended to reduce cosmetic nuisance cracking. The project concrete contractor is ultimately responsible for concrete quality and performance, and should pursue a cost-benefit analysis of these recommendations, and other options available in the industry, prior to the pouring of concrete. 7.5 RETAINING WALLS Retaining walls up to 6 feet are anticipated as part of site development. We anticipate retaining walls at the bottom of the graded slope along the north side of the property. We understand the new retaining wall is proposed to a design height of 6 feet, to include a maximum retained height of 4.5 feet and an additional 1.5 feet freeboard beyond the anticipated retained height. Retaining walls may be designed and constructed in accordance with the following Yuki Lane Development Page No. 8 Lot 2, Yuki Lane, Carlsbad, Califomia Job No. 155513-1 ENGLVEERING DESIGN GRO VP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS F )` recommendations and minimum design parameters. 7.5.a. Retaining wall footings should be designed in accordance with the allowable bearing criteria given in the "Foundations" section of this report, and should maintain minimum footing depths outlined in the "Foundations", Section 7.3, of this report. It is anticipated that all retaining wall footings will be placed on recompacted material or competent sandstone. 7.5.b. Unrestrained cantilever retaining walls should be designed using an active equivalent fluid pressure of 35 pcf. This assumes that granular, free draining material with very low potential for expansion (E. I. <20) will be used for backfill, and that the backfill surface will be level. Where soil with potential for expansion is not low (E.l. >50) a new active fluid pressure will be provided by the project soils engineer. Backfill materials should be considered prior to the design of the retaining walls to ensure accurate detailing. We anticipate onsite material will be utilized as retaining wall backfill. For sloping backfill, the parameters provided in the table below may be utilized. Backfill Sloping 2.1 Slope 1.5:1 Slope 1:5:1 or Steeper Condition Active Fluid 501 pcf 65 pcf 80 pcf Pressure Any other surcharge loadings shall be analyzed in addition to the above values. 7.5.c. If the tops of retaining walls are restrained from movement, they should be designed for an uniform at-rest soil pressure of 65 psf. 7.5.d. In moisture sensitive areas (i.e. interior living space where vapor emission is a concern), in our experience poured in place concrete provides a surface with higher performance-repairability of below grade waterproofing systems. The owner should consider the cost-benefit of utilizing cast in place building retaining walls in lieu of masonry as part of the overall construction of the residence. Waterproofing at any basement floors is recommended in areas of moisture sensitive floor finishes. 7.5.e. Retaining walls shall be designed for additional lateral forces due to earthquake, where required by code, utilizing the following design parameters. Yuki Lane Development Page No. 9 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECI-1NICAL, CML, STRUCTURAL CONSULTANTS Yielding Walls = PE= (3/8) kAE (y) H2 - applied at a distance of 0.6 times the height (H) of the wall above the base Horizontal ground acceleration value kH = 0.25g. Where non-yielding retaining walls are proposed, the specific conditions should be brought to the attention of Engineering Design Group for alternative design values. The unit weight of 120 pcf for the onsite soils may be utilized The above design parameters assume unsaturated conditions. Retaining wall designs for sites with a hydrostatic pressure influence (i.e groundwater within depth of retaining wall or waterfront conditions) will require special design considerations and should be brought to the attention of Engineering Design Group. 7.5.f. Passive soil resistance may be calculated using an equivalent fluid pressure of 300 pcf. This value assumes that the soil being utilized to resist passive pressures extends horizontally 2.5 times the height of the passive pressure wedge of the soil. Where the horizontal distance of the available passive pressure wedge is less than 2.5 times the height of the soil, the passive pressure value must be reduced by the percent reduction in available horizontal length. 7.5.g. A coefficient of friction of 0.33 between the soil and concrete footings may be utilized to resist lateral loads in addition to the passive earth pressures above. 7.5.h. All walls shall be provided with adequate back drainage to relieve hydrostatic pressure, and be designed in accordance with the minimum standards contained in the "Retaining Wall Drainage Detail", Appendix C. The waterproofing elements shown on our details are minimums, and are intended to be supplemented by the waterproofing consultant and/or architect. The recommendations should be reviewed in consideration of proposed finishes and usage, especially at basement levels, performance expectations and budget. If deemed necessary by the project owner, based on the above analysis, and waterproofing systems can be upgraded to include slab under drains and enhanced waterproofing elements. 7.5.i. Retaining wall backfill should be placed and compacted in accordance with the "Earthwork" section of this report. Backfill shall consist of soil with a very low expansion potential, granular, free draining material. 7.5.j. Retaining walls should be braced and monitored during compaction. If this cannot be accomplished, the compactive effort should be included as a surcharge load when designing the wall. Yuki Lane Development Page No. 10 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGiNEERiNG DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 8.0 SURFACE DRAINAGE Adequate drainage precautions at this site are imperative and will play a critical role on the future performance of the proposed improvements. Under no circumstances should water be allowed to pond against or adjacent to tops of slopes and/or foundation walls. The ground surface surrounding proposed improvements should be relatively impervious in nature, and slope to drain away from the structure in all directions, with a minimum slope of 2% for a horizontal distance of 7 feet (where possible). Area drains or surface swales should then be provided in low spots to accommodate runoff and avoid any ponding of water. Any french drains, backdrains and/or slab underdrains shall not be tied to surface area drain systems. Roof gutters and downspouts shall be installed on the new and existing structures and tightlined to the area drain system. All drains should be kept clean and unclogged, including gutters and downspouts. Area drains should be kept free of debris to allow for proper drainage. Over watering can adversely affect site improvements and cause perched groundwater conditions. Irrigation should be limited to only the amount necessary to sustain plant life. Low flow irrigation devices as well as automatic rain shut-off devices should be installed to reduce over watering. Irrigation practices and maintenance of irrigation and drainage systems are an important component to the performance of onsite improvements. During periods of heavy rain, the performance of all drainage systems should be inspected. Problems such as gullying or ponding should be corrected as soon as possible. Any leakage from sources such as water lines should also be repaired as soon as possible. In addition, irrigation of planter areas, lawns, or other vegetation, located adjacent to the foundation or exterior flat work improvements should be strictly controlled or avoided. 9.0 CONSTRUCTION OBSERVATION AND TESTING The recommendations provided in this report are based on subsurface conditions disclosed by the investigation and our general experience in the project area. Interpolated subsurface conditions should be verified in the field during construction. The following items shall be conducted prior/during construction by a representative of Engineering Design Group in order to verify compliance with the geotechnical and civil engineering recommendations provided herein, as applicable. The project structural and geotechnical engineers may upgrade any condition as Yuki Lane Development Page No. 11 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGiNEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS deemed necessary during the development of the proposed improvement(s). 9.1 Review of final approved grading and structural plans prior to the start of work for compliance with geotechnical recommendations. 9.2 Attendance of a pre-grade/construction meeting prior to the start of work. 9.3 Observation of subgrade and excavation bottoms. 9.4 Testing of any fill placed, including retaining wall backfill and utility trenches. 9.5 Observation of footing excavations prior to steel placement and removal of excavation equipment. 9.6 Field observation of any "field change" condition involving soils. 9.7 Walk through of final drainage detailing prior to final approval. The project soils engineer may at their discretion deepen footings or locally recommend additional steel reinforcement to upgrade any condition as deemed necessary during site observations. Engineering Design Group shall, prior to the issuance of the certificate of occupancy, issue in writing that the above inspections have been conducted by a representative of their firm, and the design considerations of the project soils report have been met. The field inspection protocol specified herein is considered the minimum necessary for Engineering Design Group to have exercised "due diligence" in the soils engineering design aspect of this building. Engineering Design Group assumes no liability for structures constructed utilizing this report not meeting this protocol. Before commencement of grading the Engineering Design Group will require a separate contract for quality control observation and testing. Engineering Design Group requires a minimum of 48 hours notice to mobilize onsite for field observation and testing. 10.0 MISCELLANEOUS It must be noted that no structure or slab should be expected to remain totally free of cracks and minor signs of cosmetic distress. The flexible nature of wood and steel structures allows them to respond to movements resulting from minor unavoidable settlement of fill or natural soils, the swelling of clay soils, or the motions induced from seismic activity. All of the above can induce movement that frequently results in cosmetic cracking of brittle wall surfaces, such as stucco or interior plaster or interior brittle slab finishes. Data for this report was derived from surface observations at the site, knowledge of local conditions, and a review of reports and plans prepared by others. The recommendations in this Yuki Lane Development Page No. 12 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CML, STRUCTURAL CONSULTANTS report are based on our experience in conjunction with the limited soils exposed at this site and neighboring sites. We believe that this information gives an acceptable degree of reliability for anticipating the behavior of the proposed improvement; however, our recommendations are professional opinions and cannot control nature, nor can they assure the soils profiles beneath or adjacent to those observed. Therefore, no warranties of the accuracy of these recommendations, beyond the limits of the obtained data, is herein expressed or implied. This report is based on the investigation at the described site and on the specific anticipated construction as stated herein. If either of these conditions is changed, the results would also most likely change. Man-made or natural changes in the conditions of a property can occur over a period of time. In addition, changes in requirements due to state of the art knowledge and/or legislation are rapidly occurring. As a result, the findings of this report may become invalid due to these changes. Therefore, this report for the specific site, is subject to review and not considered valid after a period of one year, or if conditions as stated above are altered. It is the, responsibility of the owner or his representative to ensure that the information in this report be incorporated into the plans and/or specifications and construction of the project. It is advisable that a contractor familiar with construction details typically used to deal with the local subsoil and seismic conditions be retained to build the structure. If you have any questions regarding this report, or if we can be of further service, please do not hesitate to contact us. We hope the report provides you with necessary information to continue with the development of the project. Yuki Lane Development Page No. 13 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEER1G DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS APPENDIX A REFERENCES California Geological Survey, Probabilistic Seismic Hazards Mapping Ground Motion Page. California Department of Conservation, Division of Mines and Geology, Fault Rupture Zones in California, Special Publication 42, Revised 1990. Day, Robert W. "Geotechnical and Foundation Engineering Design and Construction." 1999. McGraw Hill. Engineering Design Group, Rough Grading As-Graded Report, dated January 23, 2015. Engineering Design Group, Updated Geotechnical Investigation and Foundation Recommendation, Proposed Subdivision Located at 4400 Park Drive, Carlsbad, California. EDG Project No. 135229-1, dated October 30, 2013. Engineering Design Group, Limited Geotechnical Investigation Report, dated October 23, 2004. Engineering Design Group, Response to Comments and Addendum 3, dated October 18, 2005. Engineering Design Group, unpublished in house data. Franklin, A.G. and Chang, F.K. 1977, "Permanent displacements of Earth embankments by Newmark sliding block analysis, Report 5, Miscellaneous Paper, S 71-17, U.S. Army Corp of Engineers, Waterways Experiment Station, Vickburg, Mississippi." Greensfelder, R.W., 1974 Maximum Credible Rock Acceleration from Earthquakes in California Division of Mines and Geology, Map Sheet 23. Kennedy, Michael P. & Tan, Siang S., Geologic Map of the Oceanside, San Luis Rey, and San Marcos 7.5' Quadrangle, Sand Diego County, Californie, dated 1996. Lin, Dan, Preliminary Site Plan, 4394 Yuki Lane, dated 5-26-15. Lee, L.J., 1977, Potential foundation problems associated with earthquakes in San Diego, in Abbott, P.L. and Victoria, J.K., eds. Geologic Hazards in San Diego, Earthquakes, Landslides, and Floods: San Diego Society of Natural History John Porter Dexter Memorial Publication. Ploessel, M.R. and Slossan, i.E., 1974 Repeatable High Ground Acceleration from Earthquakes: California Geology, Vol. 27, No. 9, P. 195-199 State of California, Fault Map of California, Map No. 1, Dated 1975. State of California, Geologic Map of California, Map No. 1, Dated 1977. Structural Engineers Association of Southern California (SEAOSC) Seismology Committee, Macroseminar Presentation on Seismically Induced Earth Pressure, June 8, 2006. U.S. Army Corps of Engineers, 1985, Coast of California Storm and Tidal Waves Study, Shoreline Movement Data Report, Portuguese Point to Mexican Border, dated December U.S. Army Corps of Engineers, 1985, Coast of California Storm and Tidal Waves Study, Coastal Cliff Sediments, San Diego Region (CCSTWS 87-2), dated June. Van Dorn, W.G., 1979 Theoretical aspects of tsunamis along the San Diego coastline, in Abbott, P.L. and Elliott, W.J., Earthquakes and Other Perils: Geological Society of America field trip guidebook. Various Aerial Photographs APPENDIX B General Earthwork and Grading Specifications 1.0 General Intent These specifications are presented as general procedures and recommendations for grading and earthwork to be utilized in conjunction with the approved grading plans. These general earthwork and grading specifications are a part of the recommendations contained in the geotechnical report and shall be superseded by the recommendations in the geotechnical report in the case of conflict. Evaluations performed by the consultant during the course of grading may result in new recommendations which could supersede these specifications or the recommendations of the geotechnical report. It shall be the responsibility of the contractor to read and understand these specifications, as well as the geotechnical report and approved grading plans. 2.0 Earthwork Observation and Testing Prior to commencement of grading, a qualified geotechnical consultant should be employed for the purpose of observing earthwork procedures and testing the fills for conformance with the recommendations of the geotechnical report and these specifications. It shall be the responsibility of the contractor to assist the consultant and keep him apprised of work schedules and changes, at least 24 hours in advance, so that he may schedule his personnel accordingly. No grading operations should be performed without the knowledge of the geotechnical consultant. The contractor shall not assume that the geotechnical consultant is aware of all grading operations. It shall be the sole responsibility of the contractor to provide adequate equipment and methods to accomplish the work in accordance with the applicable grading codes and agency ordinances, recommendations in the geotechnical report and the approved grading plans not withstanding the testing and observation of the geotechnical consultant If, in the opinion of the consultant, unsatisfactory conditions, such as unsuitable soil, poor moisture condition, inadequate compaction, adverse weather, etc., are resulting in a quality of work less than recommended in the geotechnical report and the specifications, the consultant will be empowered to reject the work and recommend that construction be stopped until the conditions are rectified. Maximum dry density tests used to evaluate the degree of compaction shouls be performed in general accordance with the latest version of the American Society for Testing and Materials test method ASTM D1557. 3.0 Preparations of Areas to be Filled 3.1 Clearing and Grubbing: Sufficient brush, vegetation, roots and all other deleterious material should be removed or properly disposed of in a method acceptable to the owner, design engineer, governing agencies and the geotechnical consultant. The geotechnical consultant should evaluate the extent of these removals depending on specific site conditions. In general, no more than 1 percent (by volume) of the fill material should consist of these materials and nesting of these materials should not be allowed. 3.2 Processing: The existing ground which has been evaluated by the geotechnical consultant to be satisfactory for support of fill, should be scarified to a minimum depth of 6 inches. Existing ground which is not satisfactory should be overexcavated as specified in the following section. Scarification should continue until the soils are broken down and free of large clay lumps or clods and until the working surface is reasonably uniform, flat, and free of uneven features which would inhibit uniform compaction. 3.3 Overexcavation: Soft, dry, organic-rich, spongy, highly fractured, or otherwise unsuitable ground, extending to such a depth that surface processing cannot adequately improve the condition, should be overexcavated down to competent ground, as evaluated by the geotechnical consultant. For purposes of determining quantities of materials overexcavated, a licensed land surveyor / civil engineer should be utilized. 3.4 Moisture Conditioning: Overexcavated and processed soils should be watered, dried back, blended and I or mixed, as necessary to attain a uniform moisture content near optimum. 3.5 Recompaction: Overexcavated and processed soils which have been properly mixed, screened of deleterious material and moisture-conditioned should be recompacted to a minimum relative compaction of 90 percent or as otherwise recommended by the geotéchnical consultant. 3.6 Benching: Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical), the ground should be stepped or benched. The lowest bench should be a minimum of 15 feet wide, at least 2 feet into competent material as evaluated by the geotechnical consultant. Other benches should be excavated into competent material as evaluated by the geotechnical consultant. Ground sloping flatter than 5:1 should be benched or otherwise overexcavated when recommended by the geotechnical consultant. 3.7 Evaluation of Fill Areas: All areas to receive fill, including processed areas, removal areas and toe-of-fill benches, should be evaluated by the geotechnical consultant prior to fill placement. 4.0 Fill Material 4.1 General: Material to be placed as fill should be sufficiently free of organic matter and other deleterious substances, and should be evaluated by the geotechnical consultant prior to placement. Soils of poor gradation, expansion, or strength characteristics should be placed as recommended by the geotechnical consultant or mixed with other soils to achieve satisfactory fill material. 4.2 Oversize: Oversize material, defined as rock or other irreducible material with a maximum dimension of greater than 6 inches, should not be buried or placed in fills, unless the location, materials and disposal methods are specifically recommended by the geotechnical consultant. Oversize disposal operations should be such that nesting of oversize material does not occur, and such that the oversize material is completely surrounded by compacted or densified fill. Oversize material should not be placed within 10 feet vertically of finish grade, within 2 feet of future utilities or underground construction, or within 15 feet horizontally of slope faces, in accordance with the attached detail. 4.3 Import: If importing of fill material is required for grading, the import material should meet the requirements of Section 4.1. Sufficient time should be given to allow the geotechnical consultant to observe (and test, if necessary) the proposed import materials. 5.0 Fill Placement and Compaction 5.1 Fill Lifts: Fill material should be placed in areas prepared and previously evaluated to receive fill, in near-horizontal layers approximately 6 inches in compacted thickness. Each layer should be spread evenly and thoroughly mixed to attain uniformity of material and moisture throughout. 5.2 Moisture Conditioning: Fill soils should be watered, dried-back, blended and/or mixed, as necessary to attain a uniform moisture content near optimum. 5.3 Compaction of Fill: After each layer has been evenly spread, moisture-conditioned and mixed, it should be uniformly compacted to no less than 90 percent of maximum dry density (unless otherwise specified). Compaction equipment should be adequately sized and be either specifically designed for soil compaction or of proven reliability, to efficiently achieve the specified degree and uniformity of compaction. 5.4 Fill Slopes: Compacting of slopes should be accomplished in addition to normal compacting procedures, by backrolling of slopes with sheepsfoot rollers at increments of 3 to 4 feet in fill elevation gain, or by other methods producing satisfactory results. At the completion of grading, the relative compaction of fill out to the slope face would be at least 90 percent. 5.5 Compaction Testing: Field tests of the moisture content and degree of compaction of the fill soils should be performed at the consultant's discretion based on file dconditions encountered. In general, the tests should be taken at approximate intervals of 2 feet in vertical rise and/or 1,000 cubic yards of compacted fill soils. In addition to, on slope faces, as a guideline approximately one test should be taken for every 5,000 square feet of slope face and /or each 10 feet of vertical height of slope. 6.0 Subdrain Installation Subdrain systems, if recommended, should be installed in areas previously evaluated for suitability by the geotechnical consultant, to conform to the approximate alignment and details shown on the plans or herein. The subdrain location or materials should not be changed or modified unless recommended by the geotechnical consultant. The consultant however, may recommend changes in subdrain line or grade depending on conditions encountered. All subdrains should be surveyed by a licensed land surveyor / civil engineer for line and grade after installation. Sufficient time shall be allowed for the survey, prior to commencement of filling over the subdrains. 7.0 Excavation Excavations and cut slopes should be evaluated by a representative of the geotechnical consultant (as necessary) during grading. If directed by the geotechnical consultant, further excavation, overexcavation and refilling of cut areas and/or remedial grading of cut slopes (i.e. stability fills or slope buttresses) may be recommended. 8.0 Quantity Determination For purposes of determining quantities of materials excavated during grading and/or determining the limits of overexcavation, a licensed land surveyor / civil engineer should be utilized. SIDE HILL STABILITY FILL DETAIL EXISTING GROUND SURFACE FINISHED SLOPE FACE —FINISHE0 CUT PAD PROJECT I TO I LINE FROM TOP OF SLOPE TO OUTSIDE EDGE OF KEY .ee -.-2-C 0 UP A CTE D OVERBURDEN OR C-- ____ PAD OVEREXCAVATION DEPTH UNSUITABLE MATERIAL -:-:- 1/AIr AND RECOMPACTION MAY BE RECOMMENDED BY THE GEOTECHNICAL CONSULTANT BENCH BASED ON ACTUAL FIELD cONomoN ENCOUNTERED. 2' MIN. I COMPETENT BEDROCK OR MIN. LOWEST MATERIAL AS EVALUATED I KEY BENCH / BY THE GEOTECHNICAL .,.' DEPTH (KEY) I' CONSULTANT ----- NOTE: Subdrain details and key width recommendations to be provided based on exposed subsurface conditions 3/4•- l-112 CLEAN GRAVEL (31t3/ft. MIN.)•• 40 0 NON-PERFORATED PIPE - - - FILTER FABRIC - ENVELOPE (MIRAFI 140N OR APPROVED EQUIVALENT) * S(JBDRAI 8' NUN. COVER PERFORATED PIPE MIN. 4 MIN. BEDDING RENCH DETAIL STABILITY FILL / BUTTRESS DETAIL OUTLET PIPES -4* 0 P4ONPERFORATE0 PIPE, 100' MAX. O.C. HORIZONTALLY, 30' MAX. O.C. VERTICALLY-.., BACK CUT 1:1 OR FLATTER BENCH SEE SLiBORAIN TRENCH DETAIL LOWEST SUBORAIN SHOULD BE SITUATED AS LOW AS POSSIBLE TO ALLOW SUITABLE OUTLET KEY DEPTH I MIN. KEY WIDTH AS NOTED ON GRADING PLANS 15' HUN. ~~P -- f' 10' MIN. ERFORATED ,. EACH SIDE PIPE CAP NON-PERFORA TED OUTLET PIPE T-CONNECTION DETAIL SEE TCONNECTION 8' HUN. DETAIL OVER LA P *IF CALTRANS CLASS 2 PERMEABLE MATERIAL IS USED IN PLACE OF 3/4'-11/2' GRAVEL, FILTER FABRIC MAY BE DELETED SPECIFICATIONS FOR CALTRANS CLASS 2 PERMEABLE MATERIAL U.S. Standard Sieve Size Passing 1" 100 3/4" 90-100 3/8" 40-100 No. 4 25-40 No. 8 18-33 No. 30 5-15 No. 50 0-7 No. 200 0-3 Sand Equivalent >75 NOTES: For buttress dimensions, see geotechnical report/plans. Actual dimensions of buttress and su b d r a l f l may be changed by the g.otechnical consultant based on field conditions. $UBDRAIN INSTALLATION-Subdralfl pipe should be Installed with perforations down as depicted. At locations recommended by the geotechniCal consultant, nonperforated pipe should be Installed SUBORAIN TYPE-Subdraln type should be Acrylon true Butadlini Styrene (A.B.SJI polyvinyl Ch l o r i d e (PVC) or approved equivalent. Class 125,SOR 32.5 should be used for maximum fill depths of 35 feet. Class 200,30111 21 should be used for maximum fill depths of 100 feet. KEY AND BENCHING DETAILS FILL SLOPE PROJECT 1 TO I LINE FROM TOE OF SLOPE TO COMPETENT MATERIAL EXISTING GROUND SURFACE REMOVE UNSUITABLE MATERIAL BENCH 2' MIN •15' MIN KEY LOWEST DEPTH BENCH (KEY) FILL-OVER-CUT SLOPE EXISTING GROUND SURFACEN - - - - - - , t,- LOWEST MIN. BENCH KEY (KEY) DEPTH BENCH —REMOVE UNSUITABLE MATERIAL CUT SLOPE (TO BE EXCAVATED PRIOR TO FILL PLACEMENT) 41- / EXISTING GROUND /7 SURFACE-----.,, CUT SLOPE j (TO BE EXCAVATED PRIOR TO FILL PLACEMENT) PROJECT 1 TO 1 LINE FROM TOE OF SLOPE TO COMPETENT MATERIAL —REMOVE UNSUITABLE MATERIAL ENCH - t h' MIN- 2' MIN. LOWEST I KEY DEPTH BENCH (KEY) NOTE; Back drain may be recommended by the geotechnical consultant based on actual field conditions encountered. Bench dimension recommendations may also be altered based on field conditions encountered CUT-OVER-FILL SLOPE ROCK DISPOSAL DETAIL PINISH GRADE SLOPE FACE OVERS17-E WINDROW GRANULAR SOIL (S ~30) TO B E. E DENSIFIED IN PLACE BY F10001N0 DETAIL TYPICAL PROFILE ALONG WINDROW Rock with maximum dimensions greater than 6 inches should not be used within 10 feet vertically of finish grade (or 2 feet below depth of lowest utility whichever Is greater), and 15 feet horizontally of slope faces. Rocks with maximum dimensions greater than 4 feet should not be utilized in fills. Rock placement, flooding of granular soil, and fill placement should be observed by the geotechnical consultant. Maximum size and spacing of windrows should be in accordance with the above details Width of windrow should not exceed 4 feet. Windrows should be staggered vertically (as depicted). Rock should be placed in excavated trenches. Granular soil (S.E. greater than or equal to 30) should be flooded in the windrow to completely fill voids around and beneath rocks. APPENDIX C ENGINEERING DESIGN GROUP 2121 MONT1EL ROAD PHONE: (760) 839-7302 SAN MARCOS, CALIFORNIA 92069 FAX: (760) 480-7477 3% MIN SLOPE f1ffIffh21 WATERO$ SPECIFICATIONS (NOT TO SCALE) 1 O POAt'1 UV PROTECTION BOARD PER IlANWACTURER'S SPECIFICATION J) 2 GRACE PR000R FLUID-APPL)ED E WATERPROOFING INSTALLED PER T1ANFACTUR$ SPECIFICATIONS - 4 EXTEND BEHIND CEtENTITC4JS U BACKER BOARD. GRACE I4YDRODLJCT 220 - INSTALLED PER t1AMFACflJR R SPECIFICATIONS OVER FLUID-APPLIED WATERPROOFINS TEM'IINATIGN BAR PER 11ANLFACTUR'S ft SPECIFICATIONS () FILTER FABRIC WI 6" t'IIN LAP () 3/4" GRAVEL (I SF I PT) 7 4" DIA PERFORATED DRAIN LINE (5014 40 OR EQUIV.) PERFORATIONS ORIENTED DCW4 IS t1INllhI"I GRADIENT TO SUITABLE OUTLET - EXACT PIPE LOCATION TO BE DETE1INED BY SITE CONSTRAINTS ®4" TALL CONCRETE CANT • FTG I W4LL U CONNECTION (LINDER W4TEROCFI1W SLOPE TO BACK EDGE OF FOOTI. CG4C OR 01J - T LLL4LL PER MAN 4 DETAILS I-IYDROTITE LLL4TER- STOPS AT COLD- JOINTS PER MR INSTALLATION iNSTJCTIONS SLAB 4 VAPOR SAJER PER PLAN 4 DETAILS ®CCf1PACTED BACKFILL 90% fuN RELATIVE COIIFACTION IN ALL OTI4ER AREAS U.0)'L 6" t-IAX LIFTS. ONLY LIGJ4TUEIGA4T NAND-OPERATED EQUIPMENT SHALL BE USED WITHIN 3 FEET OF TI-IE SACK PACE OF WALL. ENGINEERING DESIGN GROUP CtTiC1C. E7L CiU CC'$ O SUIt CD ICP, 2121 Montiel Road, San Marcos, California 92069. (760) 839-7302• Fax: (760) 480-7477 www.designgroupca.com UPDATED GEOTECHNICAL RECOMMENDATIONS PROPOSED NEW SINGLE FAMILY RESIDENCE TO BE LOCATED AT LOT 2, YUKI LANE CARLSBAD, CALIFORNIA EDG Project No. 155513-1 September 3, 2015 PREPARED FOR: Pacific Beach 2014, Ltd. do San Dieguito Development Attn: Ted Montag 1106 Second St PMB 255 Encinitas, CA 92024 p: 760.635.7633 ENGINEERING DESIGN GROUP LO ff C!lIlCAt, crti. SlUiUFAJ. & PC)f1KCWr,4 CO.i5iUlr5 FO ESWM1It COMLDGIAI CONSiiJCiJft 2121 Montiel Road, San Marcos, California 92069. (760) 839-7302 Fax: (760) 480-7477 www.designgroupca.com - . . .•S#• *#*.#*.I# ' JJ*JSJ *_#Sfl_ - I IlVY TV VT .IJCOI9I 191 VJUpJL.O 1_IJI II Date: September 3, 2015 To: Pacific Beach 2014, Ltd. do San Dieguito Development Attn: Ted Montag 1106 Second St PMB 255 Encinitas, CA 92024 p: 760.635.7633 e: tedmontaq3msn.com Re: Proposed new residence to be located at Lot 2 Yuki Lane, Carlsbad, California Subject: Updated Geotechnical Report We have provided the following updated limited geotechnical report for the proposed new residence at the above referenced address. Earthwork recommendations and foundation design parameters are presented in this report. In general it is our opinion that the proposed construction, as described herein, is feasible from a geotechnical standpoint, provided the recommendations of this report and generally accepted construction practices are followed. If you have any questions regarding the following report please do not hesitate to contact our office. Sincerely, ENGINEERING DESIGN GROUP IQ on Erin E. Rist California RCE #65122 E. C 65122 4 Steven Norris California GE#2590 Table of Contents 1.0 SCOPE . 1 2.0 SITE AND PROJECT DESCRIPTION ..............................................................................1 3.0 FIELD INVESTIGATION .................................................................................................. 1 4.0 SUBSURFACE CONDITIONS .......................................................................................... 1 5.0 GROUND WATER ..........................................................................................................1 6.0 LIQUEFACTION..............................................................................................................2 7.0 CONCLUSIONS AND RECOMMENDATIONS................................................................3 7.1 GENERAL ...................................................................................................................3 7.2 EARTHWORK .............................................................................................................3 7.3 FOUNDATIONS ........................................................................................................... 4 7.4 CONCRETE SLABS ON GRADE ................................................................................6 7.5 RETAINING WALLS ....................................................................................................8 8.0 SURFACE DRAINAGE ................................................................................................... .1 9.0 CONSTRUCTION OBSERVATION AND TESTING .......................................................11 10.0 MISCELLANEOUS.........................................................................................................12 APPENDICES References.................................................................................................................Appendix A General Earthwork and Grading Specifications...........................................................Appendix B Retaining Wall Drainage Detail ..................................................................................Appendix C 1.0 SCOPE This report gives our recommendations for the proposed new residence to be constructed on Lot 2, Yuki Lane, Carlsbad, California. The scope of our work conducted onsite to date has included a visual reconnaissance of the property and surrounding areas, review of past reports, and preparation of this report presenting our findings, conclusions and recommendations. 2.0 SITE AND PROJECT DESCRIPTION The subject property consists of a graded building pad bordered to the south by single family dwellings, to the north and east by a vacant un-developed lots and to the west by Yuki Lane. The general topography of the site area consists of coastal foothill terrain. The site consists of a relatively flat building pad flanked to the north by ascending 2:1 graded slope to the lot above, to the south and west by graded descending slopes. At the time of this report the property is generally undeveloped. The building pad was graded in and around summer-fall 2014. We understand the proposed new development will consist of a new two story single family residence. 3.0 FIELD INVESTIGATION No additional subsurface investigation was conducted as part of the proposed scope of work. Grading of the subject site occurred in 2014. Engineering Design Group provided limited observation and testing during the grading of the building pads. Based upon our limited earthwork observation and testing conducted at the time of site grading fills on the order of 3-11 feet should be anticipated in the area of the proposed building pad. Fill materials general classify as SW-SM according to the Unified Soil Classification System, and based on visual observation, are considered to possess low potential for expansion. 5.0 GROUND WATER Groundwater was not encountered in during the grading of the subject property. Groundwater is not anticipated to pose a significant constraint to construction, however based upon our experience, perched groundwater conditions can develop where no such condition previously existed. _Perched _groundwater conditions can develop over time and can have a significant Yuki Lane Development Page No. 1 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGiNEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS impact, especially at basements. Waterproofing membrane shall be specifically detailed by waterproofing consultant. If groundwater conditions are encountered during site excavations, a slab underdrain system may be required. Any proposed bioretention facilities within close proximity of the residence shall be lined with an impervious waterproof barrier. Proper surface drainage and irrigation practices will play a significant role in the future performance of the project. Please note in the "Concrete Slab on Grade" section of this report for specific recommendations regarding water to cement ratio for moisture sensitive areas should be adhered. The project architect and/or waterproofing consultant shall specifically address waterproofing details. [.1sIL.lIit.tL.J It is our opinion that the site could be subjected to moderate to severe ground shaking in the event of a major earthquake along any of the faults in the Southern California region. However, the seismic risk at this site is not significantly greater than that of the surrounding developed area. Liquefaction of cohesionless soils can be caused by strong vibratory motion due to earthquakes. Research and historical data indicate that loose, granular soils underlain by a near-surface ground water table are most susceptible to liquefaction, while the stability of most silty sands and clays is not adversely affected by vibratory motion. Because of the dense nature of the soil materials underlying the site and the lack of near surface water, the potential for liquefaction or seismically-induced dynamic settlement at the site is considered low. The effects of seismic shaking can be reduced by adhering to the most recent edition of the Uniform Building Code and current design parameters of the Structural Engineers Association of California. Yuki Lane Development Page No. 2 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERiNG DESIGN GROUP GEOTECHNICAL, CML, STRUCTURAL CONSULTANTS 7.0 CONCLUSIONS AND RECOMMENDATIONS 7.1 GENERAL In general it is our opinion that the proposed new residence, as discussed and described herein, is feasible from a geotechnical standpoint, provided the recommendations of this report and all applicable codes are followed. 7.2 EARTHWORK We anticipate site grading will be limited to a shallow rip and recompact of the upper 8 inches in the area of the proposed building pad and backfill behind proposed new retaining walls and utility trenches. All grading should be done in accordance with the recommendations below as well as the standards of county and state agencies, as applicable. 7.2.a. Site Preparation Prior to any grading, the areas of proposed improvements should be cleared of surface and subsurface debris (including organic topsoil, vegetative and construction debris). Removed debris should be properly disposed of off-site prior to the commencement of any fill operations. Holes resulting from the removal of debris, existing structures, or other improvements which extend below the undercut depths noted, should be filled and compacted. 7.2.b. Removals The area of the proposed new building and settlement sensitive improvements shall be scarified with a shallow rip, approximately 8 inches, moisture conditioned and the recompacted to 90 percent minimum relative compaction. 7.2.c. Transitions All settlement sensitive improvements should be constructed on a uniform building pad. The building pad area was undercut during original grading to an approximate depth of 3-4 feet. Where new footing excavations extend beyond the area of undercut footings may require overexcavation and recompaction to a minimum of one foot below the bottom of the footing, as determined by the geotechnical engineer at the time of construction. Yuki Lane Development Page No. 3 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERiNG DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 7.2.d. Fills All new fill and backfill should be brought to approximately +2% of optimum moisture content and re-compacted to at least 90 percent relative compaction (based on ASTM D1557). Compacted fills should be cleaned of loose debris and oversize material in excess of 6 inches in diameter, brought to near optimum moisture content, and re-compacted as described above. Fills should generally be placed in lifts not exceeding 6-8 inches in thickness. Import of soil material is not anticipated, however if import material is required, soils should have a very low potential for expansion (El<20), free of debris and organic matter. Prior to importing soils, they should be visually observed, sampled and tested at the borrow pit area to evaluate soil suitability as fill. 7.2.e. Slopes Where new slopes are constructed permanent slopes may be cut to a face ratio of 2:1 (horizontal to vertical). Permanent fill slopes shall be placed at a maximum 2:1 slope face ratio. All temporary cut slopes shall be excavated in accordance with OSHA requirements and shall not undermine adjacent property or structures without proper shoring of excavation and/or structures. Subsequent to grading, planting or other acceptable cover should be provided to increase the stability of slopes, especially during the rainy season (October thru April). Contractor shall take all necessary precautions to protect improvements at the street during anticipated excavations. 7.3 FOUNDATIONS The following design parameters may be utilized for new foundations founded on competent material. 7.3.a. Footings bearing into competent sandstone or recompacted fill material may be designed utilizing maximum allowable soils pressure of 2,000 psf. 7.3.b. Seismic Design Parameters 2013 CBC Site Class D Spectral Response Coefficients Vuki Lane Development Page No. 4 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DFSIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 7.3.c. Bearing values may be increased by 33% when considering wind, seismic, or other short duration loadings. 7.3.d. The parameters in the table below should be used as a minimum for designing new footing width and depth below lowest adjacent grade into recompacted fill material. Footing depths are to be confirmed in the field by a representative of Engineering Design Group prior to the placement of form boards, steel and removal of excavation equipment. No. of Floors Supported Minimum Footing Width *Minimum Footing Depth Below Lowest Adjacent Grade 1 15 inches 18 inches 2 15 inches 18 inches 3 18 inches 24 inches 7.3.e. All footings founded into competent material should be reinforced with a minimum of two #4 bars at the top and two #4 bars at the bottom (3 inches above the ground). For footings over 30 inches in depth, additional reinforcement, and possibly a stemwall system will be necessary, and should be reviewed by project structural engineer prior to construction. 7.3.f. All isolated spread footings should be designed utilizing the above given bearing values and footing depths, and be reinforced with a minimum of #4 bars at 12 inches o.c. in each direction (3 inches above the ground). Isolated spread footings should have a minimum width and depth of 24 inches. 7.3.g. For footings adjacent to slopes a minimum of 10 feet (competent, compacted material) Yuki Lane Development Page No. 5 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGiNEERING DESIGN GROUP GEOTECIINICAL, CIVIL, STRUCTURAL CONSULTANTS and horizontal setback in competent material or properly compacted fill should be maintained. A setback measurement should be taken at the horizontal distance from the bottom of the footing to slope daylight. Where this condition cannot be met it should be brought to the attention of the Engineering Design Group for review. 7.3.h. All excavations should be performed in general accordance with the contents of this report, applicable codes, OSHA requirements and applicable city and/or county standards. 7.3.i. All foundation subgrade soils and footings shall be pre-moistened to 2% over optimum to a minimum of 18 inches in depth prior to the pouring of concrete. 7.4 CONCRETE SLABS ON GRADE We recommend the following as the minimum design parameters for new concrete slabs on grade. 7.4.a. Concrete slab on grade of the proposed building and driveway should have a minimum thickness of 5 inches and should be reinforced with #4 bars at 18 inches o.c. placed at the midpoint of the slab. 7.4.a.i Slump: Between 3 and 4 inches maximum 7.4.a.ii Aggregate Size: 3/4 - 1 inch 7.4.a.iii Moisture Sensitive Areas: At concrete slab on grade floors in moisture sensitive area (i.e. floors, below grade walls) we recommend a maximum water to cement Ratio - 0.45 maximum Compressive Strength = 4,500 psi minimum (No special inspection required for water to cement ratio purposes, unless otherwise specified by the structural engineer). This recommendation is intended to achieve a low permeability concrete. 7.4.a.iv Moisture retarding additive: in concrete at concrete slab on grade floors and moisture sensitive area 7.4.a.v Corrosion Potential: Based upon laboratory testing conducted as part of the field investigation onsite soils meet ACI exposure categories SO, Cl. The project structural engineer to note increased concrete protection requirements for corrosive environments, as applicable. EDG is not an expert in corrosion or corrosion prevention. All corrosion recommendations Yuki Lane Development Page No. 6 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGiNEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS shall be provided by the corrosion consultant. 7.4.a.vi Non-Moisture Sensitive Areas: Compressive Strength = 2,500 psi minimum. 7.4.b. In areas of level slab on grade floors we recommend a one inch layer of coarse sand material, Sand Equivalent (S.E.) greater than 50 and washed clean of fine materials, should be placed beneath the slab in moisture sensitive areas, above the vapor barrier. There shall be not greater than an 1/2 inch difference across the sand layer. 7.4.c. In moisture sensitive areas, a vapor barrier layer (15 mu) should be placed below the upper one inch of sand. The vapor barrier shall meet the following minimum requirements: . Permeance of less than 0.01 perm [grains/(ft2 hr in/Hg)] as tested in accordance with ASTM E 1745 Section 7.1. Strength per ASTM 1745 Class A. The vapor barrier should extend down the interior edge of the footing excavation a minimum of 6 inches. The vapor barrier should lap a minimum of 8 inches, sealed along all laps with the manufacturer's recommended adhesive. Beneath the vapor barrier a uniform layer of 3 inches of pea gravel is recommended under the slab in order to more uniformly support the slab, help distribute loads to the soils beneath the slab, and act as a capillary break. 7.4.d. The project waterproofing consultant should provide all slab underdrain, slab sealers and various other details, specifications and recommendations (i.e Moiststop and Linkseal) at areas of potential moisture intrusion (i.e. slab penetrations). Engineering Design Group accepts no responsibility for design or quality control of waterproofing elements of the building. 7.4.e. Adequate control joints should be installed to control the unavoidable cracking of concrete that takes place when undergoing its natural shrinkage during curing. The control joints should be well located to direct unavoidable slab cracking to areas that are desirable by the designer. 7.4.f. Any additional fills used to support slabs, should be placed in accordance with the grading section of this report, Section 7.1, and compacted to 90 percent Modified Proctor Density, ASTM D-1 557, and as described in the Earthwork section of this report. 7.4.g. All subgrade soils to receive concrete slabs and flatwork are to be pre-soaked to 2 percent over optimum moisture content to a depth of 18 inches. Yuki Lane Development Page No. 7 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGiNEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 7.4.h. Exterior concrete flatwork, due to the nature of concrete hydration and minor subgrade soil movement, are subject to normal minor concrete cracking. To minimize expected concrete cracking, the following may be implemented: Concrete may be poured with a 10 inch deep thickened edge. Flatwork adjacent to top of a slope should be constructed with an outside footing to attain a minimum of 7 feet distance to daylight. Concrete slump should not exceed 4 inches. Concrete should be poured during "cool" (40 - 65 degrees) weather if possible. If concrete is poured in hotter weather, a set retarding additive should be included in the mix, and the slump kept to a minimum. Concrete subgrade should be pre-soaked prior to the pouring of concrete. The level of pre-soaking should be a minimum of 2% over optimum moisture to a depth of 18 inches. Concrete should be constructed with tooled joints creating concrete sections no larger than 225 square feet. For sidewalks, the maximum run between joints should not exceed 5 feet. For rectangular shapes of concrete, the ratio of length to width should generally not exceed 0.6 (i.e., 5 ft. long by 3 ft. wide). Joints should be cut at expected points of concrete shrinkage (such as male corners), with diagonal reinforcement placed in accordance with industry standards. Isolation joints should be installed at exterior concrete where exterior concrete is poured adjacent to existing foundations. Drainage adjacent to concrete flatwork should direct water away from the improvement. Concrete subgrade should be sloped and directed to the collective drainage system, such that water is not trapped below the flatwork. The recommendations set forth herein are intended to reduce cosmetic nuisance cracking. The project concrete contractor is ultimately responsible for concrete quality and performance, and should pursue a cost-benefit analysis of these recommendations, and other options available in the industry, prior to the pouring of concrete. 7.5 RETAINING WALLS Retaining walls up to 6 feet are anticipated as part of site development. We anticipate retaining walls at the bottom of the graded slope along the north side of the property. We understand the new retaining wall is proposed to a design height of 6 feet, to include a maximum retained height of 4.5 feet and an additional 1.5 feet freeboard beyond the anticipated retained height. Retaining walls may be designed and constructed in accordance with the following Yulci Lane Development Page No. 8 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS recommendations and minimum design parameters. 7.5.a. Retaining wall footings should be designed in accordance with the allowable bearing criteria given in the "Foundations" section of this report, and should maintain minimum footing depths outlined in the "Foundations", Section 7.3, of this report. It is anticipated that all retaining wall footings will be placed on recompacted material or competent sandstone. 7.5.b. Unrestrained cantilever retaining walls should be designed using an active equivalent fluid pressure of 35 pcf. This assumes that granular, free draining material with very low potential for expansion (El. <20) will be used for backfill, and that the backfill surface will be level. Where soil with potential for expansion is not low (E.l. >50) a new active fluid pressure will be provided by the project soils engineer. Backfill materials should be considered prior to the design of the retaining walls to ensure accurate detailing. We anticipate onsite material will be utilized as retaining wall backfill. For sloping backfill, the parameters provided in the table below may be utilized. Backfill Sloping 2-1 Slope 5 1 Slope 1.5:1 1:5:1 or Steeper Condition Active Fluid 50 pcf 65 pcf 80 pcf Pressure Any other surcharge loadings shall be analyzed in addition to the above values. 7.5.c. If the tops of retaining walls are restrained from movement, they should be designed for an uniform at-rest soil pressure of 65 psf. 7.5.d. In moisture sensitive areas (i.e; interior living space where vapor emission is a concern), in our experience poured in place concrete provides a surface with higher performance-repairability of below grade waterproofing systems. The owner should consider the cost-benefit of utilizing cast in place building retaining walls in lieu of masonry as part of the overall construction of the residence. Waterproofing at any basement floors is recommended in areas of moisture sensitive floor finishes. 7.5.e. Retaining walls shall be designed for additional lateral forces due to earthquake, where required by code, utilizing the following design parameters. Yuki Lane Development Page No. 9 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DFSIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS Yielding Walls = PE= (3/8) kAE (y) H2 - applied at a distance of 0.6 times the height (H) of the wall above the base Horizontal ground acceleration value kH = 0.25g. Where non-yielding retaining walls are proposed, the specific conditions should be brought to the attention of Engineering Design Group for alternative design values. The unit weight of 120 pcf for the onsite soils may be utilized. The above design parameters assume unsaturated conditions. Retaining wall designs for sites with a hydrostatic pressure influence (i.e groundwater within depth of retaining wall or waterfront conditions) will require special design considerations and should be brought to the attention of Engineering Design Group. 7.5.f. Passive soil resistance may be calculated using an equivalent fluid pressure of 300 pcf. This value assumes that the soil being utilized to resist passive pressures extends horizontally 2.5 times the height of the passive pressure wedge of the soil. Where the horizontal distance of the available passive pressure wedge is less than 2.5 times the height of the soil, the passive pressure value must be reduced by the percent reduction in available horizontal length. 7.5.g. A coefficient of friction of 0.33 between the soil and concrete footings may be utilized to resist lateral loads in addition to the passive earth pressures above. 7.5.h. All walls shall be provided with adequate back drainage to relieve hydrostatic pressure, and be designed in accordance with the minimum standards contained in the "Retaining Wall Drainage Detail", Appendix C. The waterproofing elements shown on our details are minimums, and are intended to be supplemented by the waterproofing consultant and/or architect. The recommendations should be reviewed in consideration of proposed finishes and usage, especially at basement levels, performance expectations and budget. If deemed necessary by the project owner, based on the above analysis, and waterproofing systems can be upgraded to include slab under drains and enhanced waterproofing elements. 7.5.i. Retaining wall backfill should be placed and compacted in accordance with the "Earthwork" section of this report. Backfill shall consist of soil with a very low expansion potential, granular, free draining material. 7.5.j. Retaining walls should be braced and monitored during compaction. If this cannot be accomplished, the compactive effort should be included as a surcharge load when designing the wall. Yuki Lane Development Page No. 10 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGiNEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 8.0 SURFACE DRAINAGE Adequate drainage precautions at this site are imperative and will play a critical role on the future performance of the proposed improvements. Under no circumstances should water be allowed to pond against or adjacent to tops of slopes and/or foundation walls. The ground surface surrounding proposed improvements should be relatively impervious in nature, and slope to drain away from the structure in all directions, with a minimum slope of 2% for a horizontal distance of 7 feet (where possible). Area drains or surface swales should then be provided in low spots to accommodate runoff and avoid any ponding of water. Any french drains, backdrains and/or slab underdrains shall not be tied to surface area drain systems. Roof gutters and downspouts shall be installed on the new and existing structures and tightlined to the area drain system. All drains should be kept clean and unclogged, including gutters and downspouts. Area drains should be kept free of debris to allow for proper drainage. Over watering can adversely affect site improvements and cause perched groundwater conditions. Irrigation should be limited to only the amount necessary to sustain plant life. Low flow irrigation devices as well as automatic rain shut-off devices should be installed to reduce over watering. Irrigation practices and maintenance of irrigation and drainage systems are an important component to the performance of onsite improvements. During periods of heavy rain, the performance of all drainage systems should be inspected. Problems such as gullying or ponding should be corrected as soon as possible. Any leakage from sources such as water lines should also be repaired as soon as possible. In addition, irrigation of planter areas, lawns, or other vegetation, located adjacent to the foundation or exterior flat work improvements should be strictly controlled or avoided. 9.0 CONSTRUCTION OBSERVATION AND TESTING The recommendations provided in this report are based on subsurface conditions disclosed by the investigation and our general experience in the project area. Interpolated subsurface conditions should be verified in the field during construction. The following items shall be conducted prior/during construction by a representative of Engineering Design Group in order to verify compliance with the geotechnical and civil engineering recommendations provided herein, as applicable. The project structural and geotechnical engineers may upgrade any condition as Yuki Lane Development Page No. 11 Lot 2, Vuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERJNG DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS deemed necessary during the development of the proposed improvement(s). 9.1 Review of final approved grading and structural plans prior to the start of work for compliance with geotechnical recommendations. 9.2 Attendance of a pre-grade/construction meeting prior to the start of work. 9.3 Observation of subgrade and excavation bottoms. 9.4 Testing of any fill placed, including retaining wall backfill and utility trenches. 9.5 Observation of footing excavations prior to steel placement and removal of excavation equipment. 9.6 Field observation of any "field change" condition involving soils. 9.7 Walk through of final drainage detailing prior to final approval. The project soils engineer may at their discretion deepen footings or locally recommend additional steel reinforcement to upgrade any condition as deemed necessary during site observations. Engineering Design Group shall, prior to the issuance of the certificate of occupancy, issue in writing that the above inspections have been conducted by a representative of their firm, and the design considerations of the project soils report have been met. The field inspection protocol specified herein is considered the minimum necessary for Engineering Design Group to have exercised "due diligence" in the soils engineering design aspect of this building. Engineering Design Group assumes no liability for structures constructed utilizing this report not meeting this protocol. Before commencement of grading the Engineering Design Group will require a separate contract for quality control observation and testing. Engineering Design Group requires a minimum of 48 hours notice to mobilize onsite for field observation and testing. 10.0 MISCELLANEOUS It must be noted that no structure or slab should be expected to remain totally free of cracks and minor signs of cosmetic distress. The flexible nature of wood and steel structures allows them to respond to movements resulting from minor unavoidable settlement of fill or natural soils, the swelling of clay soils, or the motions induced from seismic activity. All of the above can induce movement that frequently results in cosmetic cracking of brittle wall surfaces, such as stucco or interior plaster or interior brittle slab finishes. Data for this report was derived from surface observations at the site, knowledge of local conditions, and a review of reports and plans prepared by others. The recommendations in this Yuki Lane Development Page No. 12 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEER1NG DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS report are based on our experience in conjunction with the limited soils exposed at this site and neighboring sites. We believe that this information gives an acceptable degree of reliability for anticipating the behavior of the proposed improvement; however, our recommendations are professional opinions and cannot control nature, nor can they assure the soils profiles beneath or adjacent to those observed. Therefore, no warranties of the accuracy of these recommendations, beyond the limits of the obtained data, is herein expressed or implied. This report is based on the investigation at the described site and on the specific anticipated construction as stated herein. If either of these conditions is changed, the results would also most likely change. Man-made or natural changes in the conditions of a property can occur over a period of time. In addition, changes in requirements due to state of the art knowledge and/or legislation are rapidly occurring. As a result, the findings of this report may become invalid due to these changes. Therefore, this report for the specific site, is subject to review and not considered valid after a period of one year, or if conditions as stated above are altered. It is the responsibility of the owner or his representative to ensure that the information in this report be incorporated into the plans and/or specifications and construction of the project. It is advisable that a contractor familiar with construction details typically used to deal with the local subsoil and seismic conditions be retained to build the structure. If you have any questions regarding this report, or if we can be of further service, please do not hesitate to contact us. We hope the report provides you with necessary information to continue with the development of the project. Yuki Lane Development Page No. 13 Lot 2, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGiNEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS REFERENCES California Geological Survey, Probabilistic Seismic Hazards Mapping Ground Motion Page. California Department of Conservation, Division of Mines and Geology, Fault Rupture Zones in California, Special Publication 42, Revised 1990. Day, Robert W. "Geotechnical and Foundation Engineering Design and Construction." 1999. McGraw Hill. Engineering Design Group, Rough Grading As-Graded Report, dated January 23, 2015. Engineering Design Group, Updated Geotechnical Investigation and Foundation Recommendation, Proposed Subdivision Located at 4400 Park Drive, Carlsbad, California. EDG Project No. 135229-1, dated October 30, 2013. Engineering Design Group, Limited Geotechnical Investigation Report, dated October 23, 2004. Engineering Design Group, Response to Comments and Addendum 3, dated October 18, 2005. 8. Engineering Design Group, unpublished in house data. Franklin, A.G. and Chang, F.K. 1977, "Permanent displacements of Earth embankments by Newmark sliding block analysis, Report 5, Miscellaneous Paper, 5 71-17, U.S. Army Corp of Engineers, Waterways Experiment Station, Vickburg, Mississippi." Greensfelder, R.W., 1974 Maximum Credible Rock Acceleration from Earthquakes in California Division of Mines and Geology, Map Sheet 23. Kennedy, Michael P. & Tan, Siang S., Geologic Map of the Oceanside, San Luis Rey, and San Marcos 7.5' Quadrangle, Sand Diego County, Californie, dated 1996. Lin, Dan, Preliminary Site Plan, 4394 Yuki Lane, dated 5-26-15. Lee, L.J., 1977, Potential foundation problems associated with earthquakes in San Diego, in Abbott, P.L. and Victoria, J.K., eds. Geologic Hazards in San Diego, Earthquakes, Landslides, and Floods: San Diego Society of Natural History John Porter Dexter Memorial Publication. Ploessel, M.R. and Slossan, J.E., 1974 Repeatable High Ground Acceleration from Earthquakes: California Geology, Vol. 27, No. 9, P. 195-199 State of California, Fault Map of California, Map No. 1, Dated 1975. State of California, Geologic Map of California, Map No. 1, Dated 1977. Structural Engineers Association of Southern California (SEAOSC) Seismology Committee, Macroseminar Presentation on Seismically Induced Earth Pressure, June 8, 2006. U.S. Army Corps of Engineers, 1985, Coast of California Storm and Tidal Waves Study, Shoreline Movement Data Report, Portuguese Point to Mexican Border, dated December U.S. Army Corps of Engineers, 1985, Coast of California Storm and Tidal Waves Study, Coastal Cliff Sediments, San Diego Region (CCSTWS 87-2), dated June. Van Dorn, W.G., 1979 Theoretical aspects of tsunamis along the San Diego coastline, in Abbott, P.L. and Elliott, W.J., Earthquakes and Other Perils: Geological Society of America field trip guidebook. Various Aerial Photographs APPENDIX B General Earthwork and Grading Specifications 1.0 General Intent These specifications are presented as general procedures and recommendations for grading and earthwork to be utilized in conjunction with the approved grading plans. These general earthwork and grading specifications are a part of the recommendations contained in the geotechnical report and shall be superseded by the recommendations in the geotechnical report in the case of conflict. Evaluations performed by the consultant during the course of grading may result in new recommendations which could supersede these specifications or the recommendations of the geotechnical report. It shall be the responsibility of the contractor to read and understand these specifications, as well as the geotechnical report and approved grading plans. 2.0 Earthwork Observation and Testing Prior to commencement of grading, a qualified geotechnical consultant should be employed for the purpose of observing earthwork procedures and testing the fills for conformance with the recommendations of the geotechnical report and these specifications. It shall be the responsibility of the contractor to assist the consultant and keep him apprised of work schedules and changes, at least 24 hours in advance, so that he may schedule his personnel accordingly. No grading operations should be performed without the knowledge of the geotechnical consultant. The contractor shall not assume that the geotechnical consultant is aware of all grading operations. It shall be the sole responsibility of the contractor to provide adequate equipment and methods to accomplish the work in accordance with the applicable grading codes and agency ordinances, recommendations in the geotechnical report and the approved grading plans not withstanding the testing and observation of the geotechnical consultant If, in the opinion of the consultant, unsatisfactory conditions, such as unsuitable soil, poor moisture condition, inadequate compaction, adverse weather, etc., are resulting in a quality of work less than recommended in the geotechnical report and the specifications, the consultant will be empowered to reject the work and recommend that construction be stopped until the conditions are rectified. Maximum dry density tests used to evaluate the degree of compaction shouls be performed in general accordance with the latest version of the American Society for Testing and Materials test method ASTM D1557. 3.0 Preparations of Areas to be Filled 3.1 Clearing and Grubbing: Sufficient brush, vegetation, roots and all other deleterious material should be removed or properly disposed of in a method acceptable to the owner, design engineer, governing agencies and the geotechnical consultant. The geotechnical consultant should evaluate the extent of these removals depending on specific site conditions. In general, no more than 1 percent (by volume) of the fill material should consist of these materials and nesting of these materials should not be allowed. 3.2 Processing: The existing ground which has been evaluated by the geotechnical consultant to be satisfactory for support of fill, should be scarified to a minimum depth of 6 inches. Existing ground which is not satisfactory should be overexcavated as specified in the following section. Scarification should continue until the soils are broken down and free of large clay lumps or clods and until the working surface is reasonably uniform, flat, and free of uneven features which would inhibit uniform compaction. 3.3 Overexcavation: Soft, dry, organic-rich, spongy, highly fractured, or otherwise unsuitable ground, extending to such a depth that surface processing cannot adequately improve the condition, should be overexcavated down to competent ground, as evaluated by the geotechnical consultant. For purposes of determining quantities of materials overexcavated, a licensed land surveyor I civil engineer should be utilized. 3.4 Moisture Conditioning: Overexcavated and processed soils should be watered, dried back, blended and I or mixed, as necessary to attain a uniform moisture content near optimum. 3.5 Recompaction: Overexcavated and processed soils which have been properly mixed, screened of deleterious material and moisture-conditioned should be recompacted to a minimum relative compaction of 90 percent or as otherwise recommended by the geotechnical consultant. 3.6 Benching: Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical), the ground should be stepped or benched. The lowest bench should be a minimum of 15 feet wide, at least 2 feet into competent material as evaluated by the geotechnical consultant. Other benches should be excavated into competent material as evaluated by the geotechnical consultant. Ground sloping flatter than 5:1 should be benched or otherwise overexcavated when recommended by the geotechnical consultant. 3.7 Evaluation of Fill Areas: All areas to receive fill, including processed areas, removal areas and toe-of-fill benches, should be evaluated by the geotechnical consultant prior to fill placement. 4.0 Fill Material 4.1 General: Material to be placed as fill should be sufficiently free of organic matter and other deleterious substances, and should be evaluated by the geotechnical consultant prior to placement. Soils of poor gradation, expansion, or strength characteristics should be placed as recommended by the geotechnical consultant or mixed with other soils to achieve satisfactory fill material. 4.2 Oversize: Oversize material, defined as rock or other irreducible material with a maximum dimension of greater than 6 inches, should not be buried or placed in fills, unless the location, materials and disposal methods are specifically recommended by the geotechnical consultant. Oversize disposal operations should be such that nesting of oversize material does not occur, and such that the oversize material is completely surrounded by compacted or densified fill. Oversize material should not be placed within 10 feet vertically of finish grade, within 2 feet of future utilities or underground construction, or within 15 feet horizontally of slope faces, in accordance with the attached detail. 4.3 Import: If importing of fill material is required for grading, the import material should meet the requirements of Section 4.1. Sufficient time should be given to allow the geotechnical consultant to observe (and test, if necessary) the proposed import materials. 5.0 Fill Placement and Compaction 5.1 Fill Lifts: Fill material should be placed in areas prepared and previously evaluated to receive fill, in near-horizontal layers approximately 6 inches in compacted thickness. Each layer should be spread evenly and thoroughly mixed to attain uniformity of material and moisture throughout. 5.2 Moisture Conditioning: Fill soils should be watered, dried-back, blended and/or mixed, as necessary to attain a uniform moisture content near optimum. 5.3 Compaction of Fill: After each layer has been evenly spread, moisture-conditioned and mixed, it should be uniformly compacted to no less than 90 percent of maximum dry density (unless otherwise specified). Compaction equipment should be adequately sized and be either specifically designed for soil compaction or of proven reliability, to efficiently achieve the specified degree and uniformity of compaction. 5.4 Fill Slopes: Compacting of slopes should be accomplished in addition to normal compacting procedures, by backrolling of slopes with sheepsfoot rollers at increments of 3 to 4 feet in fill elevation gain, or by other methods producing satisfactory results. At the completion of grading, the relative compaction of fill out to the slope face would be at least 90 percent. 5.5 Compaction Testing: Field tests of the moisture content and degree of compaction of the fill soils should be performed at the consultant's discretion based on file dconditions encountered. In general, the tests should be taken at approximate intervals of 2 feet in vertical rise and/or 1,000 cubic yards of compacted fill soils. In addition to, on slope faces, as a guideline approximately one test should be taken for every 5,000 square feet of slope face and /or each 10 feet of vertical height of slope. 6.0 Subdrain Installation Subdrain systems, if recommended, should be installed in areas previously evaluated for suitability by the geotechnical consultant, to conform to the approximate alignment and details shown on the plans or herein. The subdrain location or materials should not be changed or modified unless recommended by the geotechnical consultant. The consultant however, may recommend changes in subdrain line or grade depending on conditions encountered. All subdrains should be surveyed by a licensed land surveyor / civil engineer for line and grade after installation. Sufficient time shall be allowed for the survey, prior to commencement of filling over the subdrains. 7.0 Excavation Excavations and cut slopes should be evaluated by a representative of the geotechnical consultant (as necessary) during grading. If directed by the geotechnical consultant, further excavation, overexcavation and refilling of cut areas and/or remedial grading of cut slopes (i.e. stability fills or slope buttresses) may be recommended. 8.0 Quantity Determination For purposes of determining quantities of materials excavated during grading and/or determining the limits of overexcavation, a licensed land surveyor / civil engineer should be utilized. SIDE HILL STABILITY FILL DETAIL EXISTING GROUND SURFACE FINISHED SLOPE FACE -FINISHED CUT PAD PROJECTI TO I LINE FROM TOP OF SLOPE TO OUTSIDE EDGE OF KEY , /411 OVERBURDEN OR 7: UNSUITABLE PAD OVEREXCAVATION DEPTH MATERIAL -= t/AI AND RECOMPACTION MAY BE RECOMMENDED BY THE ---- GEOTECHNICAL CONSULTANT ---- BENCH BASED ON ACTUAL FIELD CONDITIONS 2' MIN. -COMPETENT BEDROCK OR MIN. LOWEST MATERIAL AS EVALUATED KEY BENCH ( BY THE GEOTECHN AL ' DEPTH (KEY) CONSULTANT NOTE: Subdrain details and key width recommendations to be provided based on exposed subsurface conditions STABILITY FILL I BUTTRESS DETAIL OUTLET PIPES -4- 0 NONPERPORATED PIPE. 100' MAX. O.C. HORIZONTALLY. 30' MAX. O.C. VERTICALLY-. BACK CUT 1:1 OR FLATTER BENCH SEE SUBORAIN TRENCH DETAIL LOWEST SUBORAIN SHOULD BE SITUATED AS LOW AS POSSIBLE TO ALLOW SUITABLE OUTLET KEY DEPTH I 2--` '-% MiN MIN. KEY WIDTH AS NOTED ON GRADING PLANS 15' MIN. 10' MIN. - PERFORATED EACH SIDE PIPE CAP NON-PERFORATED OUTLET PIPE T-.CO.NNECTION DETAIL SEE TCONNECTION 8' MIN. DETAIL OVERLAP 3/0-1-1/2' CLEAN GRAVEL (310/ft. MIN3..... 4'Ø NON-PERFORATED 4 PIPE\ .-_h - - FILTER FABRIC - ENVELOPE (MIRAFI 140N OR APPROVED EQUIVALENT) * SUBDR )'/ •I Go MIN. COVER 4'ø ..t 1 PERFORATED PIPE -- __ 4 MIN. BEDDING i TRENCH DETAIL! U.S. Standard Sieve Size Z Passing 1" 100 3/4" 90-100 3/8 40-100 No. 4 25-40 No. 8 18-33 No. 30 5-15 No. 50 0-7 No. 200 0-3 Sand Equivalent >75 * IF CALTRANS CLASS 2 PERMEABLE MATERIAL IS USED IN PLACE OF 314'-11/2' GRAVEL, FILTER FABRIC MAY BE DELETED SPECIFICATIONS FOR CALTRANS CLASS 2 PERMEABLE MATERIAL NOTES: For buttress dimensions, see geotechnical report/plans. Actual dimensions of buttress and s u b d r a i n may be changed by the gootochnical consultant based on field conditions. SUSORAIN INSTALLATION-Subdr$Ifl pipe should be Installed with perforations down as depicte d . At locations recommended by the geotechniCal consultant, nonperforated pipe should be Insta l l e d SUBDRAIN TYPE-Subdraln type should be Acrylon true Butadlifle Styrene (A.8.S.), Polyvinyl C h l o r i d e (PVC) or approved equivalent. Class 125,SOR 32.5 should be used for maximum fill depths of 35 fe e t . Class 200, SDR 21 should be used for maximum fill depths of 100 feet. KEY AND BENCHING DETAILS FILL SLOPE PROJECT I TO I LINE FROM TOE OF SLOPE TO COMPETENT MATERIAL EXISTING GROUND SURFACE REMOVE UNSUITABLE MATERIAL 'BENCH 2' MIN. is, MIN. KEY I LOWEST DEPTH BENCH (KEY) FILL-OVER-CUT SLOPE EXISTING oRou: SURF~n BENCH REMOVE UNSUITABLE 41'MiNi BENCH LOWEST MATERIAL KEY (KEY) DEPTH CUT SLOPE (TO BE EXCAVATED PRIOR TO FILL PLACEMENT) 41, EXISTING /7 GROUND SURFACE-.., CUT-OVER-FILL SLOPE PROJECT I TO 1 LINE FROM TOE OF SLOPE TO COMPETENT MATERIAL 'CUT SLOPE (TO BE EXCAVATED / PRIOR TO FILL , , PLACEMENT) -REMOVE UNSUITABLE MATERIAL ENCH - I ' MIN 2' MIN. LOWEST I KEY DEPTH BENCH (KEY) NOTE; Back drain may be recommended by the geotechnical consultant based on actual field conditions encountered. Bench dimension recommendations may also be altered based on field conditions encountered. ROCK DISPOSAL DETAIL FINISH GRADE SLOPE FACE — - - ---------------- - - - - - - - - - --------- ----------------- ---------------- E ------------------ OVERSIZE wINDROW GRANULAR SOIL (3.&a 30) TO BE DEP4SIFIED IN PLACE BY FLOODING DETAIL TYPICAL PROFILE ALONG WINDROW Rock with maximum dimensions greater than 8 inches should not be used within 10 feet vertically of finish grade (or 2 feet below depth of lowest utility whichever Is greater), and 15 feet horizontally of slope faces. Rocks with maximum dimensions greater than 4 feet should not be utilized in fills. Rock placement, flooding of granular soil1 and fill placement should be observed by th geotechnical consultant. Maximum size and spacing of windrows should be in accordance with the above details Width of windrow should not exceed 4 feet. Windrows should be staggered vertically (as depicted). Rock should be placed in excavated trenches. Granular soil (SE. greater than or equal to 30) should be flooded in the windrow to completely fill voids around and beneath. rocks. APPENDIX C ENGINEERING DESIGN GROUP 2121 MON11EL ROAD PHONE: (760) 839-7302 SAN MARCOS, CALWORNLA 92069 FAX: (760) 480-7477 3% MIN 5LOPE t.1fr1llwU1 WA it SPECIFICATIONS (NOT To SCALE) ®FOAFI UV PROTECTION SOA' PER I t14NLFACWR'5 SPECIFICATION 2 O GRACE FROCOR FLUID-APPLIED W4TERPROOFM INSTALLED PER 11AMFACTLIR'5 SPECIFICATIONS 4 -' U EXTEND BEHIND CEt1ENTITOUS i2t SACKER BOARD. GRACE 1-IYDRODUCT 220 - INSTALLED PER t1AMFACTUR R SPECIFICATIONS OVER FLUID-APPLIED WATERPROOFM TER'lINATION BAR PER 11ANLFACflJR5 z SPECIFICATIONS () FILTER FABRIC LU/ 6' t1IN LAP () 3/4" GRAVEL (I SF / FT) 7 4" DIA PEOR47ED DRAIN LINE (SC/4 40 OR EQUIV.) PERFORATIONS ORIENTED DC(LS.4 IS 1`1INTh1Ut1 GRADIENT TO SUITABLE OUTLET - EXACT PIPE LOCATION TO BE DETE1INED BY SITE CONSTRAINTS 0 4" TALL CONCRETE CANT • FTG / W4LL ° CC'1ECTICN (UNDER W4TEfr'4) SLOPE TO SACK EDGE OF FOOTfr. CC4C OR Ct1LJ - T W4LL PER PLAN 4DETAIL5 I-IYDR0TITE LLLATER- 5TOP5 AT COLD- JOINTS PER MR INSTALLATION INSTRUCTIONS SLAB 4 VAPOR SAJER PER PLAN 4 DETAILS ®CC4IPACTED SACKFILL WX MIN RELATIVE CC1PACTICfA IN ALL OTIER AREAS UDJL 6" I1A)( LIFTS. CNLY LIG4TUEI6IT I4AND-OPER4TED EQUIPMENT SHALL BE USED U/I1I4IN .3 FEET OF THE SACK FACE OF W4LL. j Ic ii cow, I / --'/4ll T V Tt1 1, H wO Mi VA -44 iz *P j L1 3j Nt Tf AJ rt'Mi 8 , . ' -!T / ''•' 1• • __ • • .• — h ' •- - V • — j V I I sAl lit -, ______ _________ t '1 i ik _tJ1rI ir,j 'c' — _*t*• &7 I I fr nil- 44 tc wm 10. m. ILA r V _ cø' *, V V •• V V - V •.L 2O 495087 EN G INEERING El'DESIGN GROUP GEOMCHNAL CIA. SIRUCTURAC S ARLUUCISMt CUSS1RIANS MR RESIDENTIAt S CUMMIACM CORSIRUCION 2121 Montiel Road, San Marcos, California 92069. (760) 839-7302 • Fax: (760) 480-7477 www.designgroupca.com UPDATED GEOTECHNICAL RECOMMENDATIONS PROPOSED NEW SINGLE FAMILY RESIDENCE TO BE LOCATED AT LOT 1, YUKI LANE CARLSBAD, CALIFORNIA EDG Project No. 155513-1 September 3, 2015 AUG 2 6 2016 LAND DEVELOPMENT PREPARED FOR: Pacific Beach 2014, Ltd. do San Dieguito Development Attn: Ted Montag 1106 Second St PMB 255 Encinitas, CA 92024 p: 760.635.7633 I ENGINEERING DESIGN GROUP storEcnnlcA&. CIVIL. ST CLUIVAL V VCHIIECiUUU CuLIUrLi UOURLSISSLLIIAL UCOIJMLTICLAL mNsmuroaq 2121 Montiel Road, San Marcos, California 92069 (760) 839-7302• Fax: (760) 480-7477 www.designgroupca.com Date: September 3, 2015 To: Pacific Beach 2014, Ltd. do San Dieguito Development Attn: Ted Montag 1106 Second St PMB 255 Encinitas, CA 92024 p: 760.635.7633 e: tedmontag3msn.com Re: Proposed new residence to be located at Lot 1 Yuki Lane, Carlsbad, California Subject: Updated Geotechnical Report We have provided the following updated limited geotechnical report for the proposed new residence at the above referenced address. Earthwork recommendations and foundation design parameters are presented in this report. In general it is our opinion that the proposed construction, as described herein, is feasible from a geotechnical standpoint, provided the recommendations of this report and generally accepted construction practices are followed. If you have any questions regarding the following report please do not hesitate to contact our office. Sincerely, ENGINEERING DESIGN GROUP E. C65122 4 Steven Norris Erin E. Rist California GE#2590 California RCE #65122 Table of Contents 1.0 SCOPE . 1 2.0 SITE AND PROJECT DESCRIPTION ..............................................................................1 3.0 FIELD INVESTIGATION .................................................................................................. i 4.0 SUBSURFACE CONDITIONS.........................................................................................1 5.0 GROUNDWATER ..........................................................................................................I 6.0 LIQUEFACTION ....................... ........................................................................................ 2 7.0 CONCLUSIONS AND RECOMMENDATIONS................................................................3 7.1 GENERAL ....................................................................................................................3 7.2 EARTHWORK ..............................................................................................................3 7.3 FOUNDATIONS...........................................................................................................4 7.4 CONCRETE SLABS ON GRADE ................................................................................6 7.5 RETAINING WALLS ....................................................................................................g 8.0 SURFACE DRAINAGE...................................................................................................11 9.0 CONSTRUCTION OBSERVATION AND TESTING .......................................................12 10.0 MISCELLANEOUS ............................................................ . ............................................ 13 APPENDICES References..................................................................................................................Appendix A General Earthwork and Grading Specifications...........................................................Appendix B Retaining Wall Drainage Detail ..................................................................................Appendix C 1.0 SCOPE This report gives our recommendations for the proposed new residence to be constructed on Lot 1, Yuki Lane, Carlsbad, California. The scope of our work conducted onsite to date has included a visual reconnaissance of the property and surrounding areas, review of past reports, and preparation of this report presenting our findings, conclusions and recommendations. 2.0 SITE AND PROJECT DESCRIPTION The subject property consists of a graded building pad bordered to the north and east be single family dwellings, to the south by a vacant un-developed lot and to the west by Yuki Lane. The general topography of the site area consists of coastal foothill terrain. The site consists of a relatively flat building pad flanked to the north by ascending slopes to the lot above, portions of which are oversteepened slopes, to the east, south and west by graded descending slopes. At the time of this report the property is generally undeveloped. The building pad was graded in and around summer-fall 2014. We understand the proposed new development will consist of a new two story single family residence. 3.0 FIELD INVESTIGATION No additional subsurface investigation was conducted as part of the proposed scope of work. Grading of the subject site occurred in 2014. Engineering Design Group provided limited observation and testing during the grading of the building pads. Based upon our limited earthwork observation and testing conducted at the time of site grading fills on the order of 3-7 feet should be anticipated in the area of the proposed building pad. Fill materials general classify as SW-SM according to the Unified Soil Classification System, and based on visual observation, are considered to possess low potential for expansion. 5.0 GROUND WATER Groundwater was not encountered in during the grading of the subject property. Groundwater is not anticipated to pose a significant constraint to construction, however based upon our experience, perched groundwater conditions can develop where no such condition previously Yuki Lane Development Page No. 1 Lot 1 Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERiNG DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS existed. Perched groundwater conditions can develop over time and can have a significant impact, especially at basements. Waterproofing membrane shall be specifically detailed by waterproofing consultant. If groundwater conditions are encountered during site excavations, a slab underdrain system may be required. Any proposed bioretention facilities within close proximity of the residence shall be lined with an impervious waterproof barrier. Proper surface drainage and irrigation practices will play a significant role in the future performance of the project. Please note in the "Concrete Slab on Grade" section of this report for specific recommendations regarding water to cement ratio for moisture sensitive areas should be adhered. The project architect and/or waterproofing consultant shall specifically address waterproofing details. It is our opinion that the site could be subjected to moderate to severe ground shaking in the event of a major earthquake along any of the faults in the Southern California region. However, the seismic risk at this site is not significantly greater than that of the surrounding developed area. Liquefaction of cohesionless soils can be caused by strong vibratory motion due to earthquakes. Research and historical data indicate that loose, granular soils underlain by a near-surface ground water table are most susceptible to liquefaction, while the stability of most silty sands and clays is not adversely affected by vibratory motion. Because of the dense nature of the soil materials underlying the site and the lack of near surface water, the potential for liquefaction or seismically-induced dynamic settlement at the site is considered low. The effects of seismic shaking can be reduced by adhering to the most recent edition of the Uniform Building Code and current design parameters of the Structural Engineers Association of California. Yuki Lane Development Page No. 2 Lot 1, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL CIVIL, STRUCTURAL CONSULTANTS 7.0 CONCLUSIONS AND RECOMMENDATIONS 7.1 GENERAL In general it is our opinion that the proposed new residence, as discussed and described herein, is feasible from a geotechnical standpoint, provided the recommendations of this report and all applicable codes are followed. We understand the new residence is proposed approximately 5 feet horizontal from the oversteepened slope along the north property line. A new retaining wall is proposed along the toe of the slope to a design height of 6 feet, to include a maximum retained height of 4.5 feet and an additional 1.5 feet freeboard beyond the anticipated retained height. See specific recommendations for the design of the retaining wall in Section 7.5 of this report. 7.2 EARTHWORK We anticipate site grading will be limited to a shallow rip and recompact of the upper 8 inches in the area of the proposed building pad and backfill behind proposed new retaining walls and utilitiy trenches. All grading should be done in accordance with the recommendations below as well as the standards of county and state agencies, as applicable. 7.2.a. Site Preparation Prior to any grading, the areas of proposed improvements should be cleared of surface and subsurface debris (including organic topsoil, vegetative and construction debris). Removed debris should be properly disposed of off-site prior to the commencement of any fill operations. Holes resulting from the removal of debris, existing structures, or other improvements which extend below the undercut depths noted, should be filled and compacted. 7.2.b. Removals The area of the proposed new building and settlement sensitive improvements shall be scarified with a shallow rip, approximately 8 inches, moisture conditioned and the recompacted to 90 percent minimum relative compaction in areas. Yuki Lane Development Page No. 3 Lot 1, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 7.2.c. Transitions All settlement sensitive improvements should be constructed on a uniform building pad. The building pad area was undercut during original grading to an approximate depth of 3 feet. Where new footing excavations extend beyond the area of undercut footings may require overexcavation and recompaction to a minimum of one foot below the bottom of the footing, as determined by the geotechnical engineer at the time of construction. 7.2.d. Fills All new fill and backfill should be brought to approximately +2% of optimum moisture content and re-compacted to at least 90 percent relative compaction (based on ASTM D1557). Compacted fills should be cleaned of loose debris and oversize material in excess of 6 inches in diameter, brought to near optimum moisture content, and re-compacted as described above. Fills should generally be placed in lifts not exceeding 6-8 inches in thickness. Import of soil material is not anticipated, however if import material is required, soils should have a very low potential for expansion (Ek20), free of debris and organic matter. Prior to importing soils, they should be visually observed, sampled and tested at the borrow pit area to evaluate soil suitability as fill. 7.2.e. Slopes Where new slopes are constructed permanent slopes may be cut to a face ratio of 2:1 (horizontal to vertical). Permanent fill slopes shall be placed at a maximum 2:1 slope face ratio. All temporary cut slopes shall be excavated in accordance with OSHA requirements and shall not undermine adjacent property or structures without proper shoring of excavation and/or structures. Subsequent to grading, planting or other acceptable cover should be provided to increase the stability of slopes, especially during the rainy season (October thru April). Contractor shall take all necessary precautions to protect improvements at the street during anticipated excavations. 7.3 FOUNDATIONS The following design parameters may be utilized for new foundations founded on competent material. 7.3.a. Footings bearing into competent sandstone or recompacted fill material may be designed Yuki Lane Development Page No. 4 Lot 1 Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS utilizing maximum allowable soils pressure of 2,000 psf. 7.3.b. Seismic Design Parameters 2013 CBC Site Class D Spectral Response Coefficients SMS (g) 1.183 SMI (g) 0.679 SDS (g) 0.789 S01 (g) 0.453 7.3.c. Bearing values may be increased by 33% when considering wind, seismic, or other short duration loadings. 7.3.d. The parameters in the table below should be used as a minimum for designing new footing width and depth below lowest adjacent grade into recompacted fill material. Footing depths are to be confirmed in the field by a representative of Engineering Design Group prior to the placement of form boards, steel and removal of excavation equipment. No. of Floors Supported Minimum Footing Width *Minimum Footing Depth Below Lowest Adjacent Grade 1 15 inches 18 inches 2 15 inches 18 inches 3 18 inches 24 inches 7.3.e. All footings founded into competent material should be reinforced with a minimum of two #4 bars at the top and two #4 bars at the bottom (3 inches above the ground). For footings over 30 inches in depth, additional reinforcement, and possibly a stemwall system will be Yuki Lane Development Page No. 5 Lot 1, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS necessary, and should be reviewed by project structural engineer prior to construction. 7.3.f. All isolated spread footings should be designed utilizing the above given bearing values and footing depths, and be reinforced with a minimum of #4 bars at 12 inches o.c. in each direction (3 inches above the ground). Isolated spread footings should have a minimum width and depth of 24 inches. 7.3.g. For footings adjacent to slopes a minimum of 10 feet (competent, compacted material) and horizontal setback in competent material or properly compacted fill should be maintained. A setback measurement should be taken at the horizontal distance from the bottom of the footing to slope daylight. Where this condition cannot be met it should be brought to the attention of the Engineering Design Group for review. 7.3.h. All excavations should be performed in general accordance with the contents of this report, applicable codes, OSHA requirements and applicable city and/or county standards. 7.3.i. All foundation subgrade soils and footings shall be pre-moistened to 2% over optimum to a minimum of 18 inches in depth prior to the pouring of concrete. 7.4 CONCRETE SLABS ON GRADE We recommend the following as the minimum design parameters for new concrete slabs on grade. Yuki Lane Development Page No. 6 Lot 1 Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 7.4.a. Concrete slab on grade of the proposed building and driveway should have a minimum thickness of 5 inches and should be reinforced with #4 bars at 18 inches o.c. placed at the midpoint of the slab. 7.4.a.i Slump: Between 3 and 4 inches maximum 7.4.a.ii Aggregate Size: 3/4 - 1 inch 7.4.a.iii Moisture Sensitive Areas: At concrete slab on grade floors in moisture sensitive area (i.e. floors, below grade walls) we recommend a maximum water to cement Ratio - 0.45 maximum Compressive Strength = 4,500 psi minimum (No special inspection required for water to cement ratio purposes, unless otherwise specified by the structural engineer). This recommendation is intended to achieve a low permeability concrete. 7.4.a.iv Moisture retarding additive: in concrete at concrete slab on grade floors and moisture sensitive area 7.4.a.v Corrosion Potential: Based upon laboratory testing conducted as part of the field investigation onsite soils meet ACI exposure categories SO, Cl. The project structural engineer to note increased concrete protection requirements for corrosive environments, as applicable. EDG is not an expert in corrosion or corrosion prevention. All corrosion recommendations shall be provided by the corrosion consultant. 7.4.a.vi Non-Moisture Sensitive Areas: Compressive Strength = 2,500 psi minimum. 7.4.b. In areas of level slab on grade floors we recommend a one inch layer of coarse sand material, Sand Equivalent (S. E.) greater than 50 and washed clean of fine materials, should be placed beneath the slab in moisture sensitive areas, above the vapor barrier. There shall be not greater than an 1/2 inch difference across the sand layer. 7.4.c. In moisture sensitive areas, a vapor barrier layer (15 mil) should be placed below the upper one inch of sand. The vapor barrier shall meet the following minimum requirements: Permeance of less than 0.01 perm [grains/(ft2 hr in/Hg)] as tested in accordance with ASTM E 1745 Section 7.1. Strength per ASTM 1745 Class A. The vapor barrier should extend down the interior edge of the footing excavation a minimum of 6 inches. The vapor barrier should lap a minimum of 8 inches, sealed Yuki Lane Development Page No. 7 Lot 1, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS along all laps with the manufacturer's recommended adhesive. Beneath the vapor barrier a uniform layer of 3 inches of pea gravel is recommended under the slab in order to more uniformly support the slab, help distribute loads to the soils beneath the slab, and act as a capillary break. 7.4.d. The project waterproofing consultant should provide all slab underdrain, slab sealers and various other details, specifications and recommendations (i.e Moiststop and Linkseal) at areas of potential moisture intrusion (i.e. slab penetrations). Engineering Design Group accepts no responsibility for design or quality control of waterproofing elements of the building. 7.4.e. Adequate control joints should be installed to control the unavoidable cracking of concrete that takes place when undergoing its natural shrinkage during curing. The control joints should be well located to direct unavoidable slab cracking to areas that are desirable by the designer. 7.4.f. Any additional fills used to support slabs, should be placed in accordance with the grading section of this report, Section 7.1, and compacted to 90 percent Modified Proctor Density, ASTM D-1 557, and as described in the Earthwork section of this report. 7.4.g. All subgrade soils to receive concrete slabs and flatwork are to be pre-soaked to 2 percent over optimum moisture content to a depth of 18 inches. 7.4.h. Exterior concrete flatwork, due to the nature of concrete hydration and minor subgrade soil movement, are subject to normal minor concrete cracking. To minimize expected concrete cracking, the following may be implemented: Concrete maybe poured with a 10 inch deep thickened edge. Flatwork adjacent to top of a slope should be constructed with an outside footing to attain a minimum of 7 feet distance to daylight. Concrete slump should not exceed 4 inches. Concrete should be poured during "cool" (40 - 65 degrees) weather if possible. If concrete is poured in hotter weather, a set retarding additive should be included in the mix, and the slump kept to a minimum. Concrete subgrade should be pre-soaked prior to the pouring of concrete. The level of pre-soaking should be a minimum of 2% over optimum moisture to a depth of 18 inches. Concrete should be constructed with tooled joints creating concrete sections no larger than 225 square feet. For sidewalks, the maximum run between joints should not exceed 5 feet. For rectangular shapes of concrete, the ratio of length to width should Yuki Lane Development Page No. 8 Lot 1 Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS generally not exceed 0.6 (i.e., 5 ft. long by 3 ft. wide). Joints should be cut at expected points of concrete shrinkage (such as male corners), with diagonal reinforcement placed in accordance with industry standards. Isolation joints should be installed at exterior concrete where exterior concrete is poured adjacent to existing foundations. Drainage adjacent to concrete flatwork should direct water away from the improvement. Concrete subgrade should be sloped and directed to the collective drainage system, such that water is not trapped below the flatwork. The recommendations set forth herein are intended to reduce cosmetic nuisance cracking. The project concrete contractor is ultimately responsible for concrete quality and performance, and should pursue a cost-benefit analysis of these recommendations, and other options available in the industry, prior to the pouring of concrete. 7.5 RETAINING WALLS Retaining walls up to 6 feet are anticipated as part of site development. We anticipate retaining walls at the bottom of the oversteepened slope along the north side of the property. Retaining walls may be designed and constructed in accordance with the following recommendations and minimum design parameters. 7.5.a. Retaining wall footings should be designed in accordance with the allowable bearing criteria given in the "Foundations" section of this report, and should maintain minimum footing depths outlined in the "Foundations", Section 7.3, of this report. It is anticipated that all retaining wall footings will be placed on recompacted material or competent sandstone. 7.5.b. Unrestrained cantilever retaining walls should be designed using an active equivalent fluid pressure of 35 pcf. This assumes that granular, free draining material with very low potential for expansion (El. <20) will be used for backfill, and that the backfill surface will be level. Where soil with potential for expansion is not low (E.l. >50) a new active fluid pressure will be provided by the project soils engineer. Backfill materials should be considered prior to the design of the retaining walls to ensure accurate detailing. We anticipate onsite material will be utilized as retaining wall backfill. For sloping backfill, the parameters provided in the table below may be utilized. Backfill Sloping 2:1 Slope 1.5:1 Slope 1:5:1 or Steeper Condition Yuki Lane Development Page No. 9 Lot 1, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGiNEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS Active Fluid 50 pcf 65 pcf 80 pcf Pressure Any other surcharge loadings shall be analyzed in addition to the above values. 7.5.c. We anticipate much of the retaining wall proposed will be designed for backfill that is 1:5 or steeper. The upper 1.5:1 feet of freeboard shall be included in the overall retained height for design purposes. 7.5.d. We recommend a debris fence extend a minimum of 24 inches above the wall to limit damage due to sloughing that will occur along the slope face. 7.5.e. If the tops of retaining walls are restrained from movement, they should be designed for an uniform at-rest soil pressure of 65 psf. 7.5.f. In moisture sensitive areas (i.e. interior living space where vapor emission is a concern), in our experience poured in place concrete provides a surface with higher performance-repairability of below grade waterproofing systems. The owner should consider the cost-benefit of utilizing cast in place building retaining walls in lieu of masonry as part of the overall construction of the residence. Waterproofing at any basement floors is recommended in areas of moisture sensitive floor finishes. 7.5.g. Retaining walls shall be designed for additional lateral forces due to earthquake, where required by code, utilizing the following design parameters. Yielding Walls = PE= (3/8) kAE (y) H2 - applied at a distance of 0.6 times the height (H) of the wall above the base Horizontal ground acceleration value kH = 0.25g. Where non-yielding retaining walls are proposed, the specific conditions should be brought to the attention of Engineering Design Group for alternative design values. The unit weight of 120 pcf for the onsite soils may be utilized. The above design parameters assume unsaturated conditions. Retaining wall designs for sites with a hydrostatic pressure influence (i.e groundwater within depth of retaining wall or waterfront conditions) will require special design considerations and should be brought to the attention of Engineering Design Group. 7.5.h. Passive soil resistance may be calculated using an equivalent fluid pressure of 300 pcf. Yuki Lane Development Page No. 10 Lot 1, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS This value assumes that the soil being utilized to resist passive pressures extends horizontally 2.5 times the height of the passive pressure wedge of the soil. Where the horizontal distance of the available passive pressure wedge is less than 2.5 times the height of the soil, the passive pressure value must be reduced by the percent reduction in available horizontal length. 7.5.i. A coefficient of friction of 0.33 between the soil and concrete footings may be utilized to resist lateral loads in addition to the passive earth pressures above. 7.5.j. All walls shall be provided with adequate back drainage to relieve hydrostatic pressure, and be designed in accordance with the minimum standards contained in the "Retaining Wall Drainage Detail", Appendix C. The waterproofing elements shown on our details are minimums, and are intended to be supplemented by the waterproofing consultant and/or architect. The recommendations should be reviewed in consideration of proposed finishes and usage, especially at basement levels, performance expectations and budget. If deemed necessary by the project owner, based on the above analysis, and waterproofing systems can be upgraded to include slab under drains and enhanced waterproofing elements. 7.5.k. Retaining wall backfill should be placed and compacted in accordance with the "Earthwork" section of this report. Backfill shall consist of soil with a very low expansion potential, granular, free draining material. 7.5.1. Retaining walls should be braced and monitored during compaction. If this cannot be accomplished, the compactive effort should be included as a surcharge load when designing the wall. 8.0 SURFACE DRAINAGE Adequate drainage precautions at this site are imperative and will play a critical role on the future performance of the proposed improvements. Under no circumstances should water be allowed to pond against or adjacent to tops of slopes and/or foundation walls. The ground surface surrounding proposed improvements should be relatively impervious in nature, and slope to drain away from the structure in all directions, with a minimum slope of 2% for a horizontal distance of 7 feet (where possible). Area drains or surface swales should then be provided in low spots to accommodate runoff and avoid any ponding of water. Any french drains, backdrains and/or slab underdrains shall not be tied to surface area drain systems. Roof gutters and downspouts shall be installed on the new and existing structures and tightlined to the area Yuki Lane Development Page No. 11 Lot 1, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS drain system. All drains should be kept clean and unclogged, including gutters and downspouts. Area drains should be kept free of debris to allow for proper drainage. Over watering can adversely affect site improvements and cause perched groundwater conditions. Irrigation should be limited to only the amount necessary to sustain plant life. Low flow irrigation devices as well as automatic rain shut-off devices should be installed to reduce over watering. Irrigation practices and maintenance of irrigation and drainage systems are an important component to the performance of onsite improvements. During periods of heavy rain, the performance of all drainage systems should be inspected. Problems such as gullying or ponding should be corrected as soon as possible. Any leakage from sources such as water lines should also be repaired as soon as possible. In addition, irrigation of planter areas, lawns, or other vegetation, located adjacent to the foundation or exterior flat work improvements should be strictly controlled or avoided. 9.0 CONSTRUCTION OBSERVATION AND TESTING The recommendations provided in this report are based on subsurface conditions disclosed by the investigation and our general experience in the project area. Interpolated subsurface conditions should be verified in the field during construction. The following items shall be conducted prior/during construction by a representative of Engineering Design Group in order to verify compliance with the geotechnical and civil engineering recommendations provided herein, as applicable. The project structural and geotechnical engineers may upgrade any condition as deemed necessary during the development of the proposed improvement(s). 9.1 Review of final approved grading and structural plans prior to the start of work for compliance with geotechnical recommendations. 9.2 Attendance of a pre-grade/construction meeting prior to the start of work. 9.3 Observation of subgrade and excavation bottoms. 9.4 Testing of any fill placed, including retaining wall backfill and utility trenches. 9.5 Observation of footing excavations prior to steel placement and removal of excavation equipment. 9.6 Field observation of any "field change" condition involving soils. 9.7 Walk through of final drainage detailing prior to final approval. The project soils engineer may at their discretion deepen footings or locally recommend additional steel reinforcement to upgrade any condition as deemed necessary during site observations. Yuki Lane Development Page No. 12 Lot 1, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERJNGDESIGNGROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS Engineering Design Group shall, prior to the issuance of the certificate of occupancy, issue in writing that the above inspections have been conducted by a representative of their firm, and the design considerations of the project soils report have been met. The field inspection protocol specified herein is considered the minimum necessary for Engineering Design Group to have exercised "due diligence" in the soils engineering design aspect of this building. Engineering Design Group assumes no liability for structures constructed utilizing this report not meeting this protocol. Before commencement of grading the Engineering Design Group will require a separate contract for quality control observation and testing. Engineering Design Group requires a minimum of 48 hours notice to mobilize onsite for field observation and testing. 10.0 MISCELLANEOUS It must be noted that no structure or slab should be expected to remain totally free of cracks and minor signs of cosmetic distress. The flexible nature of wood and steel structures allows them to respond to movements resulting from minor unavoidable settlement of fill or natural soils, the swelling of clay soils, or the motions induced from seismic activity. All of the above can induce movement that frequently results in cosmetic cracking of brittle wall surfaces, such as stucco or interior plaster or interior brittle slab finishes. Data for this report was derived from surface observations at the site, knowledge of local conditions, and a review of reports and plans prepared by others. The recommendations in this report are based on our experience in conjunction with the limited soils exposed at this site and neighboring sites. We believe that this information gives an acceptable degree of reliability for anticipating the behavior of the proposed improvement; however, our recommendations are professional opinions and cannot control nature, nor can they assure the soils profiles beneath or adjacent to those observed. Therefore, no warranties of the accuracy of these recommendations, beyond the limits of the obtained data, is herein expressed or implied. This report is based on the investigation at the described site and on the specific anticipated construction as stated herein. If either of these conditions is changed, the results would also most likely change. Man-made or natural changes in the conditions of a property can occur over a period of time. In addition, changes in requirements due to state of the art knowledge and/or legislation are rapidly occurring. As a result, the findings of this report may become invalid due to these changes. Therefore, this report for the specific site, is subject to review and not considered valid after a period of one year, or if conditions as stated above are altered. Yuki Lane Development Page No. 13 Lot 1, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS It is the responsibility of the owner or his representative to ensure that the information in this report be incorporated into the plans and/or specifications and construction of the project. It is advisable that a contractor familiar with construction details typically used to deal with the local subsoil and seismic conditions be retained to build the structure. If you have any questions regarding this report, or if we can be of further service, please do not hesitate to contact us. We hope the report provides you with necessary information to continue with the development of the project. Yuki Lane Development Page No. 14 Lot 1, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS APPENDIX A REFERENCES 1. California Geological Survey, Probabilistic Seismic Hazards Mapping Ground Motion Page. California Department of Conservation, Division of Mines and Geology, Fault Rupture Zones in California, Special Publication 42, Revised 1990. Day, Robert W. "Geotechnical and Foundation Engineering Design and Construction." 1999. McGraw Hill. Engineering Design Group, Rough Grading As-Graded Report, dated January 23, 2015. Engineering Design Group, Updated Geotechnical Investigation and Foundation Recommendation, Proposed Subdivision Located at 4400 Park Drive, Carlsbad, California. EDG Project No. 135229-1, dated October 30, 2013. Engineering Design Group, Limited Geotechnical Investigation Report, dated October 23, 2004. Engineering Design Group, Response to Comments and Addendum 3, dated October 18, 2005. Engineering Design Group, unpublished in house data. Franklin, A.G. and Chang, F.K. 1977, "Permanent displacements of Earth embankments by Newmark sliding block analysis, Report 5, Miscellaneous Paper, S 71-17, U.S. Army Corp of Engineers, Waterways Experiment Station, Vickburg, Mississippi." Greensfelder, R.W., 1974 Maximum Credible Rock Acceleration from Earthquakes in California Division of Mines and Geology, Map Sheet 23. Kennedy, Michael P. & Tan, Siang S., Geologic Map of the Oceanside, San Luis Rey, and San Marcos 7.5' Quadrangle, Sand Diego County, Californie, dated 1996. Lin, Dan, Preliminary Site Plan, dated 5-26-15. Lee, L.J., 1977, Potential foundation problems associated with earthquakes in San Diego, in Abbott, P.L. and Victoria, J.K., eds. Geologic Hazards in San Diego, Earthquakes, Landslides, and Floods: San Diego Society of Natural History John Porter Dexter Memorial Publication. Ploessel, M.R. and Slossan, J.E., 1974 Repeatable High Ground Acceleration from Earthquakes: California Geology, Vol. 27, No. 9, P. 195-199 State of California, Fault Map of California, Map No. 1, Dated 1975. State of California, Geologic Map of California, Map No. 1, Dated 1977. Structural Engineers Association of Southern California (SEAOSC) Seismology Committee, Macroseminar Presentation on Seismically Induced Earth Pressure, June 8;2006. U.S. Army Corps of Engineers, 1985, Coast of California Storm and Tidal Waves Study, Shoreline Movement Data Report, Portuguese Point to Mexican Border, dated December U.S. Army Corps of Engineers, 1985, Coast of California Storm and Tidal Waves Study, Coastal Cliff Sediments, San Diego Region (CCSTWS 87-2), dated June. Van Dorn, W.G., 1979 Theoretical aspects of tsunamis along the San Diego coastline, in Abbott, P.L. and Elliott, W.J., Earthquakes and Other Perils: Geological Society of America field trip guidebook. Various Aerial Photographs APPENDIX B General Earthwork and Grading Specifications 1.0 General Intent These specifications are presented as general procedures and recommendations for grading and earthwork to be utilized in conjunction with the approved grading plans. These general earthwork and grading specifications are a part of the recommendations contained in the geotechnical report and shall be superseded by the recommendations in the geotechnical report in the case of conflict. Evaluations performed by the consultant during the course of grading may result in new recommendations which could supersede these specifications or the recommendations of the geotechnical report. It shall be the responsibility of the contractor to read and understand these specifications, as well as the geotechnical report and approved grading plans. 2.0 Earthwork Observation and Testing Prior to commencement of grading, a qualified geotechnical consultant should be employed for the purpose of observing earthwork procedures and testing the fills for conformance with the recommendations of the geotechnical report and these specifications. It shall be the responsibility of the contractor to assist the consultant and keep him apprised of work schedules and changes, at least 24 hours in advance, so that he may schedule his personnel accordingly. No grading operations should be performed without the knowledge of the geotechnical consultant. The contractor shall not assume that the geotechnical consultant is aware of all grading operations. It shall be the sole responsibility of the contractor to provide adequate equipment and methods to accomplish the work in accordance with the applicable grading codes and agency ordinances, recommendations in the geotechnical report and the approved grading plans not withstanding the testing and observation of the geotechnical consultant If, in the opinion of the consultant, unsatisfactory conditions, such as unsuitable soil, poor moisture condition, inadequate compaction, adverse weather, etc., are resulting in a quality of work less than recommended in the geotechnical report and the specifications, the consultant will be empowered to reject the work and recommend that construction be stopped until the conditions are rectified. Maximum dry density tests used to evaluate the degree of compaction shouls be performed in general accordance with the latest version of the American Society for Testing and Materials test method ASTM D1557. 3.0 Preparations of Areas to be Filled 3.1 Clearing and Grubbing: Sufficient brush, vegetation, roots and all other deleterious material should be removed or properly disposed of in a method acceptable to the owner, design engineer, governing agencies and the geotechnical consultant. The geotechnical consultant should evaluate the extent of these removals depending on specific site conditions. In general, no more than 1 percent (by volume) of the fill material should consist of these materials and nesting of these materials should not be allowed. 3.2 Processing: The existing ground which has been evaluated by the geotechnical consultant to be satisfactory for support of fill, should be scarified to a minimum depth of 6 inches. Existing ground which is not satisfactory should be overexcavated as specified in the following section. Scarification should continue until the soils are broken down and free of large clay lumps or clods and until the working surface is reasonably uniform, flat, and free of uneven features which would inhibit uniform compaction. 3.3 Overexcavation: Soft, dry, organic-rich, spongy, highly fractured, or otherwise unsuitable ground, extending to such a depth that surface processing cannot adequately improve the condition, should be overexcavated down to competent ground, as evaluated by the geotechnical consultant. For purposes of determining quantities of materials overexcavated, a licensed land surveyor I civil engineer should be utilized. 3.4 Moisture Conditioning: Overexcavated and processed soils should be watered, dried back, blended and I or mixed, as necessary to attain a uniform moisture content near optimum. 3.5 Recompaction: Overexcavated and processed soils which have been properly mixed, screened of deleterious material and moisture-conditioned should be recompacted to a minimum relative compaction of 90 percent or as otherwise recommended by the geotechnical consultant. 3.6 Benching: Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical), the ground should be stepped or benched. The lowest bench should be a minimum of 15 feet wide, at least 2 feet into competent material as evaluated by the geotechnical consultant. Other benches should be excavated into competent material as evaluated by the geotechnical consultant. Ground sloping flatter than 5:1 should be benched or otherwise overexcavated when recommended by the geotechnical consultant. 3.7 Evaluation of Fill Areas: All areas to receive fill, including processed areas, removal areas and toe-of-fill benches, should be evaluated by the geotechnical consultant prior to fill placement. 4.0 Fill Material 4.1 General: Material to be placed as fill should be sufficiently free of organic matter and other deleterious substances, and should be evaluated by the geotechnical consultant prior to placement. Soils of poor gradation, expansion, or strength characteristics should be placed as recommended by the geotechnical consultant or mixed with other soils to achieve satisfactory fill material. 4.2 Oversize: Oversize material, defined as rock or other irreducible material with a maximum dimension of greater than 6 inches, should not be buried or placed in fills, unless the location, materials and disposal methods are specifically recommended by the geotechnical consultant. Oversize disposal operations should be such that nesting of oversize material does not occur, and such that the oversize material is completely surrounded by compacted or densified fill. Oversize material should not be placed within 10 feet vertically of finish grade, within 2 feet of future utilities or underground construction, or within 15 feet horizontally of slope faces, in accordance with the attached detail. 4.3 Import: If importing of fill material is required for grading, the import material should meet the requirements of Section 4.1. Sufficient time should be given to allow the geotechnical consultant to observe (and test, if necessary) the proposed import materials. 5.0 Fill Placement and Compaction 5.1 Fill Lifts: Fill material should be placed in areas prepared and previously evaluated to receive fill, in near-horizontal layers approximately 6 inches in compacted thickness. Each layer should be spread evenly and thoroughly mixed to attain uniformity of material and moisture throughout. 5.2 Moisture Conditioning: Fill soils should be watered, dried-back, blended and/or mixed, as necessary to attain a uniform moisture content near optimum. 5.3 Compaction of Fill: After each layer has been evenly spread, moisture-conditioned and mixed, it should be uniformly compacted to no less than 90 percent of maximum dry density (unless otherwise specified). Compaction equipment should be adequately sized and be either specifically designed for soil compaction or of proven reliability, to efficiently achieve the specified degree and uniformity of compaction. 5.4 Fill Slopes: Compacting of slopes should be accomplished in addition to normal compacting procedures, by backrolling of slopes with sheepsfoot rollers at increments of 3 to 4 feet in fill elevation gain, or by other methods producing satisfactory results. At the completion of grading, the relative compaction of fill out to the slope face would be at least 90 percent. 5.5 Compaction Testing: Field tests of the moisture content and degree of compaction of the fill soils should be performed at the consultant's discretion based on file dconditions encountered. In general, the tests should be taken at approximate intervals of 2 feet in vertical rise and/or 1,000 cubic yards of compacted fill soils. In addition to, on slope faces, as a guideline approximately one test should be taken for every 5,000 square feet of slope face and /or each 10 feet of vertical height of slope. 6.0 Subdrain Installation Subdrain systems, if recommended, should be installed in areas previously evaluated for suitability by the geotechnical consultant, to conform to the approximate alignment and details shown on the plans or herein. The subdrain location or materials should not be changed or modified unless recommended by the geotechnical consultant. The consultant however, may recommend changes in subdrain line or grade depending on conditions encountered. All subdrains should be surveyed by a licensed land surveyor / civil engineer for line and grade after installation. Sufficient time shall be allowed for the survey, prior to commencement of filling over the subdrains. 7.0 Excavation Excavations and cut slopes should be evaluated by a representative of the geotechnical consultant (as necessary) during grading. If directed by the geotechnical consultant, further excavation, overexcavation and refilling of cut areas and/or remedial grading of cut slopes (i.e. stability fills or slope buttresses) may be recommended. 8.0 Quantity Determination For purposes of determining quantities of materials excavated during grading and/or determining the limits of overexcavation, a licensed land surveyor I civil engineer should be utilized. SIDE HILL STABILITY FILL DETAIL 2'is,MIN. MIN. LOWEST KEY BENCH DEPTH (KEY) EXISTING GROUND SURFACE-.. - , ...—FINISHED CUT PAD rA2 ( PAD OVEREXCAVATION DEPTH t/AL. AND RECOMPACTION MAY BE RECOMMENDED BY THE GEOTECHNICAL CONSULTANT BENCH BASED ON ACTUAL FIELD CONDITIONS--ENCOUNTERED. ...._—COMPETENT BEDROCK OR MATERIAL AS EVALUATED ( BY THE GEOTECHNICAL V CONSULTANT - FINISHED SLOPE FACE PROJECT 1 TO I LINE FROM TOP OF SLOPE TO OUTSIDE EDGE OF KEY ' OVERBURDEN OR UNSUITABLE MATERIAL NOTE: Subdrain details and key width recommendations to be provided based on exposed subsurface conditions KEY DEPTH --------- MIN. - I W1ii' KEY WIDTH AS NOTED ON GRADING PLANS 15' MIN. SEE TCONNEC1'1ON 0' PAIN. // DETAIL OVERLAPS 314'-1-112' CLEAN GRAVEL (31t?/ft. 4' JO NON-PERFORATED PIPE - - - - FILTER FABRIC - ENVELOPE (MIRAFI 140N OR APPROVED EQUIVALENT) * I 'It 0' MIN. I' COVER 4. 0 PERFORATED PIPE 5% MIN. 4' MIN. BEDDING DRAIN TRENCH DETAIL STABILITY FILL I BUTTRESS DETAIL OUTLET PIPES -4' 0 P4ONPERPORATEO PIPE. 100' MAX. O.C. HORIZONTALLY. 30' MAX. O.C. VERTlCALLY-., BACK CUT 1:1 OR FLATTER BENCH SEE SUBORAIN TRENCH DETAIL LOWEST SUBORAIN SHOULD BE SITUATED AS LOW AS POSSIBLE TO ALLOW SUITABLE OUTLET PERFORATED 10' PAIN. PIPE . EACH SIDE CAP NON-PERFORATED OUTLET PIPE T-CONNECTION DETAIL * IF CALTRANS CLASS 2 PERMEABLE MATERIAL IS USED IN PLACE OF 3/4'-11/2' GRAVEL, FILTER FABRIC MAY BE DELETED SPECIFICATIONS FOR CALTRANS CLASS 2 PERMEABLE MATERIAL U.S. Standard Sieve Size % Passing ill 100 3/4' 90-100 3/8 ' 40-100 No. 4 25-40 No. 8 18-33 No. 30 5-15 No. 50 0-7 No. 200 0-3 Sand Equivalent >75 NOTES: For buttress dimensions, $ee geotechnical reportlplafla. Actual dimensions of buttress and subdraifl may be changed by the geotechnical consultant based on field conditions. SUEDRAIN INSTALLATION-Subdtalfl pipe should be Installed with perforations down as depicted. At locations recommended by the geotechriiCal consultant, nonperforated pipe should be installed SUBORAIN TYPE-Subdraln type should be Acrylon trlle 8utadlefle Styrene (A.8.S.), polyvinyl Chloride (PVC) or approved equivalent. Class 125,SOR 32.5 should be used for maximum till depths of 35 feet. Class 200, SOR 21 should be used for maximum fill depths of 100 feet. KEY AND BENCHING DETAILS FILL SLOPE PROJECT 1 TO I LINE FROM TOE OF SLOPE TO COMPETENT MATERIAL EXISTING GROUND SURFACE REMOVE UNSUITABLE MATERIAL BENCH 2' MIN KEY DEPTH :15' MIN.—H LOWEST BENCH (KEY) FILL—OVER—CUT SLOPE EXISTING - GROUND SURFACE\ - H_15'-MIN.--i - 2 LOWEST ±• BENCH DEPTH (KEY) CUT SLOPE (TO BE EXCAVATED PRIOR TO FILL BENCH -REMOVE UNSUITABLE MATERIAL PLACEMENT) , -- CUT—OVER—FILL SLOPE PROJECT I TO 1 LINE FROM TOE OF SLOPE TO COMPETENT MATERIAL ..- , EXISTING GROUND SURFACE ,L••.fl( I CUT SLOPE (TO BE EXCAVATED PRIOR TO FILL PLACEMENT) —REMOVE UNSUITABLE MATERIAL ENCH - t 1='' MIN' 2' MIN. LOWEST I KEY DEPTH BENCH (KEY) NOTE: Back drain may be recommended by the geotechnical consultant based on actual field conditions encountered. Bench dimension recommendations may also be altered based on field conditions encountered. ROCK DISPOSAL DETAIL FINISH GRADE SLOPE FACE ------------------ OVERSIZE WINDROW GRANULAR SOIL (S E.2t 30) TO BE DEPISIFIED IN PLACE BY FLOODING DETAIL TYPICAL PROFILE ALONG WINDROW Rock with maximum dimensions greater than 6 inches should not be used within 10 feet vertically of finish grade (or 2 feet below depth of lowest utility whichever is greater), and 15 feet horizontally of slope faces. Rocks with maximum dimensions greater than 4 feet should not be utilized in fills. Rock placement, flooding of granular soil, and fill placement should be observed by the geotechnical consultant. Maximum size and spacing of windrows should be in accordance with the above details Width of windrow should not exceed 4 feet. Windrows should be staggered vertically. (as depicted). Rock should be placed in excavated trenches. Granular soil (S.E. greater than or equal to 30) should be flooded in the windrow to completely fill voids around and beneath rocks. APPENDIX C 3% MIN SLOPE ENGINEERING DESIGN GROUP 2121 MONTIEL ROAD PHONE: (760) 839-7302 SAN MARCOS, CALIFORNIA 92069 FAX: (760) 480-7477 t1IIJff1J1 WATEP.Ocff! 8FECIFICATIG45 (NOT TO SCALE) 1 O FOAM UV PROTECTION BOARD PER t'1ANLFAC71JR5 SPECIFICATION tf 2 O GRACE PROCOR FLUID-APPLIED E • WATEROC INSTALLED PER Lu t1ANLFACTUR'5 SPECIFICATIONS -i U 4 EXTEND SENIND CEt1ENTITOJS SACKER BOARD. 3 GRACE I4YDRODLJCT 220 - INSTALLED PER t'1AMPACWS SPECIFICATIC'45 OVER FLUID-APPLIED W41E?ROCII' TE4TIGN BAR PER MANUFACTURER'S SPECIFICATIONS IC FILTER FABRIC WI 6" MIN LAP () 3/4" GRAVEL (I SF I PT) 7 4" DIA PERFORATED DRAIN LINE (5C14 40 OR EQUIV) PEOR4TICt45 ORIENTED 00U?4 IS tllNifltl GRADIENT TO SUITASLE OUTLET - EXACT PIPE LOCATION TO SE DETE1INED BY SITE CONSTRAINTS O 4" TALL CONCRETE CANT . FTG I U.L4LL 8 CONNECTION (UNDER W4TEROOFif) SLOPE TO SACK EDGE OF FOOTif. Ca1C OR CHU - ?T W4LI. PER PLAN 4 DETAILS 1-IYDROTITE 1U47ER- STOPS AT COLD- JOINTS PER t INSTALLATION if 5TRJCTIct45 SLAB 4 VAPOR BARRIER PER PLAN 4 DETAILS ®CQIPACTED SAC.I(FILL 90% 1`1IN RELATIVE CCNPACTICt4 IN ALL OTIER AREAS U.OJL 6" t"IA)c LIFTS. ONLY LIGUTUEIGIT I44ND -OPERA TED EQUIPMENT 514ALL SE USED WI1I4if'J 3 FEET OF TUE SACK FACE OF WALL. ENGINEERING DESIGN GROUP [OIECHNCAI. Cr, SIUiUA I RC IIfCTUR4L cjsiL Alit s FOR fSiUTlL & COMMUCIALCONSTRUCION 2121 Montiel Road, San Marcos, California 92069. (760) 839-7302. Fax: (760) 480-7477 www.designgroupca.com UPDATED GEO TECHNICAL RECOMMENDATIONS PROPOSED NEW SINGLE FAMILY RESIDENCE TO BE LOCATED AT LOT 1, YUKI LANE CARLSBAD, CALIFORNIA EDG Project No. 155513-1 September 3, 2015 PREPARED FOR: Pacific Beach 2014, Ltd. do San Dieguito Development Attn: Ted Montag 1106 Second St PMB 255 Encinitas, CA 92024 p: 760.635.7633 ENGINEERING DESIGN GROUP G1OICuiCAL CrlL SLiCiURA ARC UFM CSUUAIIS FOR RESIDAHIIAL A COUMARCtAR CONSIAliCilON 2121 Montiel Road, San Marcos, California 92069. (760) 839-7302 Fax: (760) 480-7477 • www.designgroupca.com Date: September 3, 2015 To: Pacific Beach 2014, Ltd. do San Dieguito Development Attn: Ted Montag 1106 Second St PMB 255 Encinitas, CA 92024 p: 760.635.7633 e: tedmontag3(msn.com Re: Proposed new residence to be located at Lot I Yuki Lane, Carlsbad, California Subject: Updated Geotechnical Report We have provided the following updated limited geotechnical report for the proposed new residence at the above referenced address. Earthwork recommendations and foundation design parameters are presented in this report. In general it is our opinion that the proposed construction, as described herein, is feasible from a geotechnical standpoint, provided the recommendations of this report and generally accepted construction practices are followed. If you have any questions regarding the following report please do not hesitate to contact our office. Sincerely, ENGINEERING DESIGN GROUP E. iS (t C65122 Steven Norris Erin E. Rist California GE#2590 California RCE #65122 Table of Contents 1.0 SCOPE . 1 2.0 SITE AND PROJECT DESCRIPTION .............................................................................1 3.0 FIELD INVESTIGATION..................................................................................................1 4.0 SUBSURFACE CONDITIONS ......................................................................................... I 5.0 GROUNDWATER ..........................................................................................................1 6.0 LIQUEFACTION .............................................................................................................. 2 7.0 CONCLUSIONS AND RECOMMENDATIONS................................................................3 7.1 GENERAL ...................................................................................................................3 7.2 EARTHWORK .............................................................................................................3 7.3 FOUNDATIONS...........................................................................................................4 7.4 CONCRETE SLABS ON GRADE ................................................................................6 7.5 RETAINING WALLS ....................................................................................................9 8.0 SURFACE DRAINAGE...................................................................................................11 9.0 CONSTRUCTION OBSERVATION AND TESTING .......................................................12 10.0 MISCELLANEOUS.........................................................................................................13 APPENDICES References.................................................................................................................Appendix A General Earthwork and Grading Specifications ........................................................... Appendix B Retaining Wall Drainage Detail ..................................................................................Appendix C 1.0 SCOPE This report gives our recommendations for the proposed new residence to be constructed on Lot 1, Yuki Lane, Carlsbad, California. The scope of our work conducted onsite to date has included a visual reconnaissance of the property and surrounding areas, review of past reports, and preparation of this report presenting our findings, conclusions and recommendations. 2.0 SITE AND PROJECT DESCRIPTION The subject property consists of a graded building pad bordered to the north and east be single family dwellings, to the south by a vacant un-developed lot and to the west by Yuki Lane. The general topography of the site area consists of coastal foothill terrain. The site consists of a relatively flat building pad flanked to the north by ascending slopes to the lot above, portions of which are oversteepened slopes, to the east, south and west by graded descending slopes. At the time of this report the property is generally undeveloped. The building pad was graded in and around summer-fall 2014. We understand the proposed new development will consist of a new two story single family residence. 3.0 HELD INVESTIGATION No additional subsurface investigation was conducted as part of the proposed scope of work. Grading of the subject site occurred in 2014. Engineering Design Group provided limited observation and testing during the grading of the building pads. Based upon our limited earthwork observation and testing conducted at the time of site grading fills on the order of 3-7 feet should be anticipated in the area of the proposed building pad. Fill materials general classify as SW-SM according to the Unified Soil Classification System, and based on visual observation, are considered to possess low potential for expansion. 5.0 GROUND WATER Groundwater was not encountered in during the grading of the subject property. Groundwater is not anticipated to pose a significant constraint to construction, however based upon our experience, perched groundwater conditions can develop where no such condition previously Yuki Lane Development Page No. 1 Lot 1, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS existed. Perched groundwater conditions can develop over time and can have a significant impact, especially at basements. Waterproofing membrane shall be specifically detailed by waterproofing consultant. If groundwater conditions are encountered during site excavations, a slab underdrain system may be required. Any proposed bioretention facilities within close proximity of the residence shall be lined with an impervious waterproof barrier. Proper surface drainage and irrigation practices will play a significant role in the future performance of the project. Please note in the "Concrete Slab on Grade" section of this report for specific recommendations regarding water to cement ratio for moisture sensitive areas should be adhered. The project architect and/or waterproofing consultant shall specifically address waterproofing details. It is our opinion that the site could be subjected to moderate to severe ground shaking in the event of a major earthquake along any of the faults in the Southern California region. However, the seismic risk at this site is not significantly greater than that of the surrounding developed area. Liquefaction of cohesionless soils can be caused by strong vibratory motion due to earthquakes. Research and historical data indicate that loose, granular soils underlain by a near-surface ground water table are most susceptible to liquefaction, while the stability of most silty sands and clays is not adversely affected by vibratory motion. Because of the dense nature of the soil materials underlying the site and the lack of near surface water, the potential for liquefaction or seismically-induced dynamic settlement at the site is considered low. The effects of seismic shaking can be reduced by adhering to the most recent edition of the Uniform Building Code and current design parameters of the Structural Engineers Association of California. Yuki Lane Development Page No. 2 Lot 1, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 7.0 CONCLUSIONS AND RECOMMENDATIONS 7.1 GENERAL In general it is our opinion that the proposed new residence, as discussed and described herein, is feasible from a geotechnical standpoint, provided the recommendations of this report and all applicable codes are followed. We understand the new residence is proposed approximately 5 feet horizontal from the oversteepened slope along the north property line. A new retaining wall is proposed along the toe of the slope to a design height of 6 feet, to include a maximum retained height of 4.5 feet and an additional 1.5 feet freeboard beyond the anticipated retained height. See specific recommendations for the design of the retaining wall in Section 7.5 of this report. 7.2 EARTHWORK We anticipate site grading will be limited to a shallow rip and recompact of the upper 8 inches in the area of the proposed building pad and backfill behind proposed new retaining walls and utilitiy trenches. All grading should be done in accordance with the recommendations below as well as the standards of county and state agencies, as applicable. 7.2.a. Site Preparation Prior to any grading, the areas of proposed improvements should be cleared of surface and subsurface debris (including organic topsoil, vegetative and construction debris). Removed debris should be properly disposed of off-site prior to the commencement of any fill operations. Holes resulting from the removal of debris, existing structures, or other improvements which extend below the undercut depths noted, should be filled and compacted. 7.2.b. Removals The area of the proposed new building and settlement sensitive improvements shall be scarified with a shallow rip, approximately 8 inches, moisture conditioned and the recompacted to 90 percent minimum relative compaction in areas. Yuki Lane Development Page No. 3 Lot 1, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGiNEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 7.2.c. Transitions All settlement sensitive improvements should be constructed on a uniform building pad. The building pad area was undercut during original grading to an approximate depth of 3 feet. Where new footing excavations extend beyond the area of undercut footings may require overexcavation and recompaction to a minimum of one foot below the bottom of the footing, as determined by the geotechnical engineer at the time of construction. 7.2.d. Fills All new fill and backfill should be brought to approximately +2% of optimum moisture content and re-compacted to at least 90 percent relative compaction (based on ASTM D1557). Compacted fills should be cleaned of loose debris and oversize material in excess of 6 inches in diameter, brought to near optimum moisture content, and re-compacted as described above. Fills should generally be placed in lifts not exceeding 6-8 inches in thickness. Import of soil material is not anticipated, however if import material is required, soils should have a very low potential for expansion (Ek20), free of debris and organic matter. Prior to importing soils, they should be visually observed, sampled and tested at the borrow pit area to evaluate soil suitability as fill. 7.2.e. Slopes Where new slopes are constructed permanent slopes may be cut to a face ratio of 2:1 (horizontal to vertical). Permanent fill slopes shall be placed at a maximum 2:1 slope face ratio. All temporary cut slopes shall be excavated in accordance with OSHA requirements and shall not undermine adjacent property or structures without proper shoring of excavation and/or structures. Subsequent to grading, planting or other acceptable cover should be provided to increase the stability of slopes, especially during the rainy season (October thru April). Contractor shall take all necessary precautions to protect improvements at the street during anticipated excavations. 7.3 FOUNDATIONS The following design parameters may be utilized for new foundations founded on competent material. 7.3.a. Footings bearing into competent sandstone or recompacted fill material may be designed Yuki Lane Development Page No. 4 Lot 1, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS utilizing maximum allowable soils pressure of 2,000 psf. 7.3.b. Seismic Design Parameters 2013 CBC Site Class D Spectral Response Coefficients SMS (g) 1.183 SMI (g) , 0.679 SDS (g) 0.789 SW (g) 0.453 7.3.c. Bearing values may be increased by 33% when considering wind, seismic, or other short duration loadings. 7.3.d. The parameters in the table below should be used as a minimum for designing new footing width and depth below lowest adjacent grade into recompacted fill material. Footing depths are to be confirmed in the field by a representative of Engineering Design Group prior to the placement of form boards, steel and removal of excavation equipment. No. of Floors Supported Minimum Footing Width *Minimum Footing Depth Below Lowest Adjacent Grade 1 15 inches 18 inches 2 15 inches 18 inches 3 18 inches 24 inches 7.3.e. All footings founded into competent material should be reinforced with a minimum of two #4 bars at the top and two #4 bars at the bottom (3 inches above the ground). For footings over 30 inches in depth, additional reinforcement, and possibly a stemwall system will be Yuki Lane Development Page No. 5 Lot 1 Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS necessary, and should be reviewed by project structural engineer prior to construction. 7.3.f. All isolated spread footings should be designed utilizing the above given bearing values and footing depths, and be reinforced with a minimum of #4 bars at 12 inches D.C. in each direction (3 inches above the ground). Isolated spread footings should have a minimum width and depth of 24 inches. 7.3.g. For footings adjacent to slopes a minimum of 10 feet (competent, compacted material) and horizontal setback in competent material or properly compacted fill should be maintained. A setback measurement should be taken at the horizontal distance from the bottom of the footing to slope daylight. Where this condition cannot be met it should be brought to the attention of the Engineering Design Group for review. 7.3.h. All excavations should be performed in general accordance with the contents of this report, applicable codes, OSHA requirements and applicable city and/or county standards. 7.3.i. All foundation subgrade soils and footings shall be pre-moistened to 2% over optimum to a minimum of 18 inches in depth prior to the pouring of concrete. 7.4 CONCRETE SLABS ON GRADE We recommend the following as the minimum design parameters for new concrete slabs on grade. Yuki Lane Development Page No. 6 Lot 1, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 7.4.a. Concrete slab on grade of the proposed building and driveway should have a minimum thickness of 5 inches and should be reinforced with #4 bars at 18 inches D.C. placed at the midpoint of the slab. 7.4.a.i Slump: Between 3 and 4 inches maximum 7.4.a.ii Aggregate Size: 3/4 - 1 inch 7.4.a.iii Moisture Sensitive Areas: At concrete slab on grade floors in moisture sensitive area (i.e. floors, below grade walls) we recommend a maximum water to cement Ratio - 0.45 maximum Compressive Strength = 4,500 psi minimum (No special inspection required for water to cement ratio purposes, unless otherwise specified by the structural engineer). This recommendation is intended to achieve a low permeability concrete. 7.4.a.iv Moisture retarding additive: in concrete at concrete slab on grade floors and moisture sensitive area 7.4.a.v Corrosion Potential: Based upon laboratory testing conducted as part of the field investigation onsite soils meet ACl exposure categories SO, Cl. The project structural engineer to note increased concrete protection requirements for corrosive environments, as applicable. EDG is not an expert in corrosion or corrosion prevention. All corrosion recommendations shall be provided by the corrosion consultant. 7.4.a.vi Non-Moisture Sensitive Areas: Compressive Strength = 2,500 psi minimum. 7.4.b. In areas of level slab on grade floors we recommend a one inch layer of coarse sand material, Sand Equivalent (S.E.) greater than 50 and washed clean of fine materials, should be placed beneath the slab in moisture sensitive areas, above the vapor barrier. There shall be not greater than an 1/2 inch difference across the sand layer. 7.4.c. In moisture sensitive areas, a vapor barrier layer (15 mil) should be placed below the upper one inch of sand. The vapor barrier shall meet the following minimum requirements: Permeance of less than 0.01 perm [grains/(ft2 hr in/Hg)] as tested in accordance with ASTM E 1745 Section 7.1. Strength per ASTM 1745 Class A. The vapor barrier should extend down the interior edge of the footing excavation a minimum of 6 inches. The vapor barrier should lap a minimum of 8 inches, sealed Yuki Lane Development Page No. 7 Lot 1, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERiNG DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS along all laps with the manufacturer's recommended adhesive. Beneath the vapor barrier a uniform layer of 3 inches of pea gravel is recommended under the slab in order to more uniformly support the slab, help distribute loads to the soils beneath the slab, and act as a capillary break. 7.4.d. The project waterproofing consultant should provide all slab underdrain, slab sealers and various other details, specifications and recommendations (i.e Moiststop and Linkseal) at areas of potential moisture intrusion (i.e. slab penetrations). Engineering Design Group accepts no responsibility for design or quality control of waterproofing elements of the building. 7.4.e. Adequate control joints should be installed to control the unavoidable cracking of concrete that takes place when undergoing its natural shrinkage during curing. The control joints should be well located to direct unavoidable slab cracking to areas that are desirable by the designer. 7.4.1. Any additional fills used to support slabs, should be placed in accordance with the grading section of this report, Section 7. 1, and compacted to 90 percent Modified Proctor Density, ASTM D-1557, and as described in the Earthwork section of this report. 7.4.g. All subgrade soils to receive concrete slabs and flatwork are to be pre-soaked to 2 percent over optimum moisture content to a depth of 18 inches. 7.4.h. Exterior concrete flatwork, due to the nature of concrete hydration and minor subgrade soil movement, are subject to normal minor concrete cracking. To minimize expected concrete cracking, the following may be implemented: Concrete maybe poured with a 10 inch deep thickened edge. Flatwork adjacent to top of a slope should be constructed with an outside footing to attain a minimum of 7 feet distance to daylight. Concrete slump should not exceed 4 inches. Concrete should be poured during "cool" (40 - 65 degrees) weather if possible. If concrete is poured in hotter weather, a set retarding additive should be included in the mix, and the slump kept to a minimum. Concrete subgrade should be pre-soaked prior to the pouring of concrete. The level of pie-soaking should be a minimum 012% over optimum moisture to a depth of 18 inches. Concrete should be constructed with tooled joints creating concrete sections no larger than 225 square feet. For sidewalks, the maximum run between joints should not exceed 5 feet. For rectangular shapes of concrete, the ratio of length to width should Yuki Lane Development Page No. 8 Lot 1 Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CML, STRUCTURAL CONSULTANTS generally not exceed 0.6 (i.e., 5 ft. long by 3 ft. wide). Joints should be cut at expected points of concrete shrinkage (such as male corners), with diagonal reinforcement placed in accordance with industry standards. Isolation joints should be installed at exterior concrete where exterior concrete is poured adjacent to existing foundations. Drainage adjacent to concrete flatwork should direct water away from the improvement. Concrete subgrade should be sloped and directed to the collective drainage system, such that water is not trapped below the flatwork. The recommendations set forth herein are intended to reduce cosmetic nuisance cracking. The project concrete contractor is ultimately responsible for concrete quality and performance, and should pursue a cost-benefit analysis of these recommendations, and other options available in the industry, prior to the pouring of concrete. 7.5 RETAINING WALLS Retaining walls up to 6 feet are anticipated as part of site development. We anticipate retaining walls at the bottom of the oversteepened slope along the north side of the property. Retaining walls may be designed and constructed in accordance with the following recommendations and minimum design parameters. 7.5.a. Retaining wall footings should be designed in accordance with the allowable bearing criteria given in the "Foundations" section of this report, and should maintain minimum footing depths outlined in the "Foundations", Section 7.3, of this report. It is anticipated that all retaining wall footings will be placed on recompacted material or competent sandstone. 7.5.b. Unrestrained cantilever retaining walls should be designed using an active equivalent fluid pressure of 35 pcf. This assumes that granular, free draining material with very low potential for expansion (E. I. <20) will be used for backfill, and that the backfill surface will be level. Where soil with potential for expansion is not low (E.I. >50) a new active fluid pressure will be provided by the project soils engineer. Backfill materials should be considered prior to the design of the retaining walls to ensure accurate detailing. We anticipate onsite material will be utilized as retaining wall backfill. For sloping backfill, the parameters provided in the table below may be utilized. Backfill Sloping 2:1 Slope 15:1 Slope 1:5:1 or Steeper Condition Yuki Lane Development Page No. 9 Lot 1, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERIG DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS Active Fluid 50 pcf 65 pcf 80 pcf Pressure Any other surcharge loadings shall be analyzed in addition to the above values. 7.5.c. We anticipate much of the retaining wall proposed will be designed for backfill that is 1:5 or steeper. The upper 1.5:1 feet of freeboard shall be included in the overall retained height for design purposes. 7.5.d. We recommend a debris fence extend a minimum of 24 inches above the wall to limit damage due to sloughing that will occur along the slope face. 7.5.e. If the tops of retaining walls are restrained from movement, they should be designed for an uniform at-rest soil pressure of 65 psf. 7.5.f. In moisture sensitive areas (i.e. interior living space where vapor emission is a concern), in our experience poured in place concrete provides a surface with higher performance-repairability of below grade waterproofing systems. The owner should consider the cost-benefit of utilizing cast in place building retaining walls in lieu of masonry as part of the overall construction of the residence. Waterproofing at any basement floors is recommended in areas of moisture sensitive floor finishes. 7.5.g. Retaining walls shall be designed for additional lateral forces due to earthquake, where required by code, utilizing the following design parameters. Yielding Walls = PE= (3/8) kAE (y) H2 - applied at a distance of 0.6 times the height (H) of the wall above the base Horizontal ground acceleration value kH = 0.25g. Where non-yielding retaining walls are proposed, the specific conditions should be brought to the attention of Engineering Design Group for alternative design values. The unit weight of 120 pcf for the onsite soils may be utilized. The above design parameters assume unsaturated conditions. Retaining wall designs for sites with a hydrostatic pressure influence (i.e groundwater within depth of retaining wall or waterfront conditions) will require special design considerations and should be brought to the attention of Engineering Design Group. 7.5.h. Passive soil resistance may be calculated using an equivalent fluid pressure of 300 pcf. Yuki Lane Development Page No. 10 Lot 1, Yuki Lane, Carlsbad, Califomia Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNCAL, CIVIL, STRUCTURAL CONSULTANTS This value assumes that the soil being utilized to resist passive pressures extends horizontally 2.5 times the height of the passive pressure wedge of the soil. Where the horizontal distance of the available passive pressure wedge is less than 2.5 times the height of the soil, the passive pressure value must be reduced by the percent reduction in available horizontal length. 7.5.i. A coefficient of friction of 0.33 between the soil and concrete footings may be utilized to resist lateral loads in addition to the passive earth pressures above. 7.5.j. All walls shall be provided with adequate back drainage to relieve hydrostatic pressure, and be designed in accordance with the minimum standards contained in the "Retaining Wall Drainage Detail", Appendix C. The waterproofing elements shown on our details are minimums, and are intended to be supplemented by the waterproofing consultant and/or architect. The recommendations should be reviewed in consideration of proposed finishes and usage, especially at basement levels, performance expectations and budget. If deemed necessary by the project owner, based on the above analysis, and waterproofing systems can be upgraded to include slab under drains and enhanced waterproofing elements. 7.5.k. Retaining wall backfill should be placed and compacted in accordance with the "Earthwork" section of this report. Backfill shall consist of soil with a very low expansion potential, granular, free draining material. 7.5.1. Retaining walls should be braced and monitored during compaction. If this cannot be accomplished, the compactive effort should be included as a surcharge load when designing the wall. 8.0 SURFACE DRAINAGE Adequate drainage precautions at this site are imperative and will play a critical role on the future performance of the proposed improvements. Under no circumstances should water be allowed to pond against or adjacent to tops of slopes and/or foundation walls. The ground surface surrounding proposed improvements should be relatively impervious in nature, and slope to drain away from the structure in all directions, with a minimum slope of 2% for a horizontal distance of 7 feet (where possible). Area drains or surface swales should then be provided in low spots to accommodate runoff and avoid any ponding of water. Any french drains, backdrains and/or slab underdrains shall not be tied to surface area drain systems. Roof gutters and downspouts shall be installed on the new and existing structures and tightlined to the area Yuki Lane Development Page No. 11 Lot 1, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CML, STRUCTURAL CONSULTANTS drain system. All drains should be kept clean and unclogged, including gutters and downspouts. Area drains should be kept free of debris to allow for proper drainage. Over watering can adversely affect site improvements and cause perched groundwater conditions. Irrigation should be limited to only the amount necessary to sustain plant life. Low flow irrigation devices as well as automatic rain shut-off devices should be installed to reduce over watering. Irrigation practices and maintenance of irrigation and drainage systems are an important component to the performance of onsite improvements. During periods of heavy rain, the performance of all drainage systems should be inspected. Problems such as gullying or ponding should be corrected as soon as possible. Any leakage from sources such as water lines should also be repaired as soon as possible. In addition, irrigation of planter areas, lawns, or other vegetation, located adjacent to the foundation or exterior flat work improvements should be strictly controlled or avoided. 9.0 CONSTRUCTION OBSERVATION AND TESTING The recommendations provided in this report are based on subsurface conditions disclosed by the investigation and our general experience in the project area. Interpolated subsurface conditions should be verified in the field during construction. The following items shall be conducted prior/during construction by a representative of Engineering Design Group in order to verify compliance with the geotechnical and civil engineering recommendations provided herein, as applicable. The project structural and geotechnical engineers may upgrade any condition as deemed necessary during the development of the proposed improvement(s). 9.1 Review of final approved grading and structural plans prior to the start of work for compliance with geotechnical recommendations. 9.2 Attendance of a pre-grade/construction meeting prior to the start of work. 9.3 Observation of subgrade and excavation bottoms. 9.4 Testing of any fill placed, including retaining wall backfill and utility trenches. 9.5 Observation of footing excavations prior to steel placement and removal of excavation equipment. 9.6 Field observation of any "field change" condition involving soils. 9.7 Walk through of final drainage detailing prior to final approval. The project soils engineer may at their discretion deepen footings or locally recommend additional steel reinforcement to upgrade any condition as deemed necessary during site observations. Yuki Lane Development Page No. 12 Lot 1 Yuki Lane, Carlsbad, Califomia Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHNICAL CIVIL, STRUCTURAL CONSULTANTS Engineering Design Group shall, prior to the issuance of the certificate of occupancy, issue in writing that the above inspections have been conducted by a representative of their firm, and the design considerations of the project soils report have been met. The field inspection protocol specified herein is considered the minimum necessary for Engineering Design Group to have exercised "due diligence" in the soils engineering design aspect of this building. Engineering Design Group assumes no liability for structures constructed utilizing this report not meeting this protocol. Before commencement of grading the Engineering Design Group will require a separate contract for quality control observation and testing. Engineering Design Group requires a minimum of 48 hours notice to mobilize onsite for field observation and testing. 10.0 MISCELLANEOUS It must be noted that no structure or slab should be expected to remain totally free of cracks and minor signs of cosmetic distress. The flexible nature of wood and steel structures allows them to respond to movements resulting from minor unavoidable settlement of fill or natural soils, the swelling of clay soils, or the motions induced from seismic activity. All of the above can induce movement that frequently results in cosmetic cracking of brittle wall surfaces, such as stucco or interior plaster or interior brittle slab finishes. Data for this report was derived from surface observations at the site, knowledge of local conditions, and a review of reports and plans prepared by others. The recommendations in this report are based on our experience in conjunction with the limited soils exposed at this site and neighboring sites. We believe that this information gives an acceptable degree of reliability for anticipating the behavior of the proposed improvement; however, our recommendations are professional opinions and cannot control nature, nor can they assure the soils profiles beneath or adjacent to those observed. Therefore, no warranties of the accuracy of these recommendations, beyond the limits of the obtained data, is herein expressed or implied. This report is based on the investigation at the described site and on the specific anticipated construction as stated herein. If either of these conditions is changed, the results would also most likely change. Man-made or natural changes in the conditions of a property can occur over a period of time. In addition, changes in requirements due to state of the art knowledge and/or legislation are rapidly occurring. As a result, the findings of this report may become invalid due to these changes. Therefore, this report for the specific site, is subject to review and not considered valid after a period of one year, or if conditions as stated above are altered. Yuki Lane Development Page No. 13 Lot 1, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGINEERING DESIGN GROUP GEOTECHMCAL, CIVIL, STRUCTURAL CONSULTANTS It is the responsibility of the owner or his representative to ensure that the information in this report be incorporated into the plans and/or specifications and construction of the project. It is advisable that a contractor familiar with construction details typically used to deal with the local subsoil and seismic conditions be retained to build the structure. If you have any questions regarding this report, or if we can be of further service, please do not hesitate to contact us. We hope the report provides you with necessary information to continue with the development of the project. Yuki Lane Development Page No. 14 Lot 1, Yuki Lane, Carlsbad, California Job No. 155513-1 ENGiNEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS APPENDIX A REFERENCES 1. California Geological Survey, Probabilistic Seismic Hazards Mapping Ground Motion Page. California Department of Conservation, Division of Mines and Geology, Fault Rupture Zones in California, Special Publication 42, Revised 1990. Day, Robert W. "Geotechnical and Foundation Engineering Design and Construction." 1999. McGraw Hill. Engineering Design Group, Rough Grading As-Graded Report, dated January 23, 2015. Engineering Design Group, Updated Geotechnical Investigation and Foundation Recommendation, Proposed Subdivision Located at 4400 Park Drive, Carlsbad, California. EDG Project No. 135229-1, dated October 30, 2013. Engineering Design Group, Limited Geotechnical Investigation Report, dated October 23, 2004. Engineering Design Group, Response to Comments and Addendum 3, dated October 18, 2005. Engineering Design Group, unpublished in house data. Franklin, A.G. and Chang, F.K. 1977, "Permanent displacements of Earth embankments by Newmark sliding block analysis, Report 5, Miscellaneous Paper, S 71-17, U.S. Army Corp of Engineers, Waterways Experiment Station, Vickburg, Mississippi." Greensfelder, R.W., 1974 Maximum Credible Rock Acceleration from Earthquakes in California Division of Mines and Geology, Map Sheet 23. Kennedy, Michael P. & Tan, Siang S., Geologic Map of the Oceanside, San Luis Rey, and San Marcos 7.5' Quadrangle, Sand Diego County, Californie, dated 1996. Lin, Dan, Preliminary Site Plan, dated 5-26-15. Lee, L.J., 1977, Potential foundation problems associated with earthquakes in San Diego, in Abbott, P.L. and Victoria, J.K., eds. Geologic Hazards in San Diego, Earthquakes, Landslides, and Floods: San Diego Society of Natural History John Porter Dexter Memorial Publication. Ploessel, M.R. and Slossan, i.E., 1974 Repeatable High Ground Acceleration from Earthquakes: California Geology, Vol. 27, No. 9, P. 195-199 State of California, Fault Map of California, Map No. 1, Dated 1975. State of California, Geologic Map of California, Map No. 1, Dated 1977. Structural Engineers Association of Southern California (SEAOSC) Seismology Committee, Macroseminar Presentation on Seismically Induced Earth Pressure, June 8, 2006. U.S. Army Corps of Engineers, 1985, Coast of California Storm and Tidal Waves Study, Shoreline Movement Data Report, Portuguese Point to Mexican Border, dated December U.S. Army Corps of Engineers, 1985, Coast of California Storm and Tidal Waves Study, Coastal Cliff Sediments, San Diego Region (CCSTWS 87-2), dated June. Van Dorn, W.G., 1979 Theoretical aspects of tsunamis along the San Diego coastline, in Abbott, P.L. and Elliott, W.J., Earthquakes and Other Perils: Geological Society of America field trip guidebook. Various Aerial Photographs APPENDIX B General Earthwork and Grading Specifications 1.0 General Intent These specifications are presented as general procedures and recommendations for grading and earthwork to be utilized in conjunction with the approved grading plans. These general earthwork and grading specifications are a part of the recommendations contained in the geotechnical report and shall be superseded by the recommendations in the geotechnical report in the case of conflict. Evaluations performed by the consultant during the course of grading may result in new recommendations which could supersede these specifications or the recommendations of the geotechnical report. It shall be the responsibility of the contractor to read and understand these specifications, as well as the geotechnical report and approved grading plans. 2.0 Earthwork Observation and Testing Prior to commencement of grading, a qualified geotechnical consultant should be employed for the purpose of observing earthwork procedures and testing the fills for conformance with the recommendations of the geotechnical report and these specifications. It shall be the responsibility of the contractor to assist the consultant and keep him apprised of work schedules and changes, at least 24 hours in advance, so that he may schedule his personnel accordingly. No grading operations should be performed without the knowledge of the geotechnical consultant. The contractor shall not assume that the geotechnical consultant is aware of all grading operations. It shall be the sole responsibility of the contractor to provide adequate equipment and methods to accomplish the work in accordance with the applicable grading codes and agency ordinances, recommendations in the geotechnical report and the approved grading plans not withstanding the testing and observation of the geotechnical consultant If, in the opinion of the consultant, unsatisfactory conditions, such as unsuitable soil, poor moisture condition, inadequate compaction, adverse weather, etc., are resulting in a quality of work less than recommended in the geotechnical report and the specifications, the consultant will be empowered to reject the work and recommend that construction be stopped until the conditions are rectified. Maximum dry density tests used to evaluate the degree of compaction shouls be performed in general accordance with the latest version of the American Society for Testing and Materials test method ASTM D1557. 3.0 Preparations of Areas to be Filled 3.1 Clearing and Grubbing: Sufficient brush, vegetation, roots and all other deleterious material should be removed or properly disposed of in a method acceptable to the owner, design engineer, governing agencies and the geotechnical consultant. The geotechnical consultant should evaluate the extent of these removals depending on specific site conditions. In general, no more than 1 percent (by volume) of the fill material should consist of these materials and nesting of these materials should not be allowed. 3.2 Processing: The existing ground which has been evaluated by the geotechnical consultant to be satisfactory for support of fill, should be scarified to a minimum depth of 6 inches. Existing ground which is not satisfactory should be overexcavated as specified in the following section. Scarification should continue until the soils are broken down and free of large clay lumps or clods and until the working surface is reasonably uniform, flat, and free of uneven features which would inhibit uniform compaction. 3.3 Overexcavation: Soft, dry, organic-rich, spongy, highly fractured, or otherwise unsuitable ground, extending to such a depth that surface processing cannot adequately improve the condition, should be overexcavated down to competent ground, as evaluated by the geotechnical consultant. For purposes of determining quantities of materials overexcavated, a licensed land surveyor / civil engineer should be utilized. 3.4 Moisture Conditioning: Overexcavated and processed soils should be watered, dried back, blended and I or mixed, as necessary to attain a uniform moisture content near optimum. 3.5 Recompaction: Overexcavated and processed soils which have been properly mixed, screened of deleterious material and moisture-conditioned should be recompacted to a minimum relative compaction of 90 percent or as otherwise recommended by the geotechnical consultant. 3.6 Benching: Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical), the ground should be stepped or benched. The lowest bench should be a minimum of 15 feet wide, at least 2 feet into competent material as evaluated by the geotechnical consultant. Other benches should be excavated into competent material as evaluated by the geotechnical consultant. Ground sloping flatterthan 5:1 should be benched or otherwise overexcavated when recommended by the geotechnical consultant. 3.7 Evaluation of Fill Areas: All areas to receive fill, including processed areas, removal areas and toe-of-fill benches, should be evaluated by the geotechnical consultant prior to fill placement. 4.0 Fill Material 4.1 General: Material to be placed as fill should be sufficiently free of organic matter and other deleterious substances, and should be evaluated by the geotechnical consultant prior to placement. Soils of poor gradation, expansion, or strength characteristics should be placed as recommended by the geotechnical consultant or mixed with other soils to achieve satisfactory fill material. 4.2 Oversize: Oversize material, defined as rock or other irreducible material with a maximum dimension of greater than 6 inches, should not be buried or placed in fills, unless the location, materials and disposal methods are specifically recommended by the geotechnical consultant. Oversize disposal operations should be such that nesting of oversize material does not occur, and such that the oversize material is completely surrounded by compacted or densified fill. Oversize material should not be placed within 10 feet vertically of finish grade, within 2 feet of future utilities or underground construction, or within 15 feet horizontally of slope faces, in accordance with the attached detail. 4.3 Import: If importing of fill material is required for grading, the import material should meet the requirements of Section 4.1. Sufficient time should be given to allow the geotechnical consultant to observe (and test, if necessary) the proposed import materials. 5.0 Fill Placement and Compaction 5.1 Fill Lifts: Fill material should be placed in areas prepared and previously evaluated to receive fill, in near-horizontal layers approximately 6 inches in compacted thickness. Each layer should be spread evenly and thoroughly mixed to attain uniformity of material and moisture throughout. 5.2 Moisture Conditioning: Fill soils should be watered, dried-back, blended and/or mixed, as necessary to attain a uniform moisture content near optimum. 5.3 Compaction of Fill: After each layer has been evenly spread, moisture-conditioned and mixed, it should be uniformly compacted to no less than 90 percent of maximum dry density (unless otherwise specified). Compaction equipment should be adequately sized and be either specifically designed for soil compaction or of proven reliability, to efficiently achieve the specified degree and uniformity of compaction. 5.4 Fill Slopes: Compacting of slopes should be accomplished in addition to normal compacting procedures, by backrolling of slopes with sheepsfoot rollers at increments of 3 to 4 feet in fill elevation gain, or by other methods producing satisfactory results. At the completion of grading, the relative compaction of fill out to the slope face would be at least 90 percent. 5.5 Compaction Testing: Field tests of the moisture content and degree of compaction of the fill soils should be performed at the consultant's discretion based on file dconditions encountered. In general, the tests should be taken at approximate intervals of 2 feet in vertical rise and/or 1,000 cubic yards of compacted fill soils. In addition to, on slope faces, as a guideline approximately one test should be taken for every 5,000 square feet of slope face and /or each 10 feet of vertical height of slope. 6.0 Subdrain Installation Subdrain systems, if recommended, should be installed in areas previously evaluated for suitability by the geotechnical consultant, to conform to the approximate alignment and details shown on the plans or herein. The subdrain location or materials should not be changed or modified unless recommended by the geotechnical consultant. The consultant however, may recommend changes in subdrain line or grade depending on conditions encountered. All subdrains should be surveyed by a licensed land surveyor / civil engineer for line and grade after installation. Sufficient time shall be allowed for the survey, prior to commencement of filling over the subdrains. 7.0 Excavation Excavations and cut slopes should be evaluated by a representative of the geotechnical consultant (as necessary) during grading. If directed by the geotechnical consultant, further excavation, overexcavation and refilling of cut areas and/or remedial grading of cut slopes (i.e. stability fills or slope buttresses) may be recommended. 8.0 Quantity Determination For purposes of determining quantities of materials excavated during grading and/or determining the limits of overexcavation, a licensed land surveyor / civil engineer should be utilized. SIDE HILL STABILITY FILL DETAIL 2# L15 MIN. MIN. LOWEST KEY BENCH DEPTH (KEY) EXISTING GROUND SURFACE... - .- ,.—FINISHED CUT PAD 2COMPACTEQ PAD OVEREXCAVATION DEPTH %iI.. AND RECOMPACTION MAY BE RECOMMENDED BY THE GEOTECHNICAL CONSULTANT BENCH BASED ON ACTUAL FIELD CONDITIONS-.ENCOUNTERED. ...—COMPETENT BEDROCK OR ,- MATERIAL AS EVALUATED A ( BY THE GEOTECHNICAL " CONSULTANT - FINISHED SLOPE FACE PROJECT 1 TO 1 LINE FROM TOP OF SLOPE TO OUTSIDE EDGE OF KEY 'N OVERBURDEN OR UNSUITABLE MATERIAL.. NOTE: Subdrain details and key width recommendations to be provided based on exposed subsurface conditions 0' MIN. / OVERLAP / 314'-1-1/2' CLEAN GRAVEL (3f13/ft. MINJ.. : 4Ø NON-PERFORATED j PIPE - FILTER FABRIC - ENVELOPE (MIRAFI 140N OR APPROVED EQUIVALENT) * SEE TCONNECTION DETAIL SL 6 MIN. COVER ¶PERFORATED PIPE 4 MIN. BEDDING STABILITY FILL / BUTTRESS DETAIL OUTLET PIPES -4- 0 NONPERFORATED PIPE, 100' MAX. O.C. HORIZONTALLY. 30' MAX. O.C. VERTICALLY-S —BACK CUT 1:1 OR FLATTER ',—BENCH SEE SUBORAIN TRENCH DETAIL o -c LOWEST SUBORAIN SHOULD BE SITUATED AS LOW AS POSSIBLE TO ALLOW SUITABLE OUTLET (—" 10' MIN. ~ER ORATED t EACH SIDE CAP OUTLET PIPE T-CONNECTION DETAIL * IF CALTRANS CLASS 2 PERMEABLE MATERIAL IS USED IN PLACE OF 3/4-1-1/2 GRAVEL, FILTER FABRIC MAY BE DELETED SPECIFICATIONS FOR CALTRANS CLASS 2 PERMEABLE MATERIAL U.S. Standard Sieve Size Z Passing 1" 100 3/4' 90-100 40-100 No. 4 25-40 No. 8 18-33 No. 30 S-IS No. 50 0-7 No. 200 0-3 KEY DEPTH I MIN. MIN--r-2 - t%fIII' I ft KEY WIDTH AS NOTED ON GRADING PLANS is, MIN. SUBDRAIN TRENCH DETAIL Sand Equivalent >75 NOTES: For buttress dimensions, see geotechnical report/plans. Actual dimensions of but and subdraifl may be changed by the geotechniCal consultant based On field conditions. SUBDRAiN INSTALLATIONSUbdraIn pipe should be Installed with perforations down as depicte d . At locations recommended by the geotechniCal consultant, nonperforated pipe should be inst a l l e d SUBORAIN TYPE-Subdraln type should be Acrylon trile Butadiene Styrene (A.B.S.), Polyvinyl Chloride (PVC) or approved equivalent. Class 125,S0R 32.5 should be used for maximum fill depths of 3 5 f e e t . Class 200, SOR 21 should be used for maximum fill depths of 100 KEY AND BENCHING DETAILS FILL SLOPE PROJECT 1 TO 1 LINE FROM TOE OF SLOPE TO COMPETENT MATERIAL EXISTING GROUND SURFACE REMOVE UNSUITABLE MATERIAL BENCH - 2' MIN.-15' MIN. KEY I LOWEST DEPTH BENCH (KEY) FILL-OVER-CUT SLOPE EXISTING GROUND SURF;n,,, BENCH REMOVE UNSUITABLE 2' LOWEST MIN. BENCH MATERIAL KEY (KEY) DEPTH If CUT SLOPE (TO BE EXCAVATED PRIOR TO FILL PLACEMENT) EXISTING /v GROUND SURFACE—... CUT-OVER-FILL SLOPE PROJECT I 70 1 LINE FROM TOE OF SLOPE TO COMPETENT MATERIAL CUT SLOPE (TO BE EXCAVATED PRIOR TO FILL Ile PLACEMENT) -REMOVE UNSUITABLE MATERIAL ENCH - t t.._!15. MIN 2' MIN, LOWEST KEY DEPTH BENCH (KEY) NOTE: Back drain may be recommended by the geotechnical consultant based on actual field conditions encountered. Bench dimension recommendations may - also be altered based on field conditions encountered. ROCK DISPOSAL DETAIL FINISH GRADE SLOPE FACE F1 ----------------------- ---------------------- -------------------- OVERSIZE WINDROW GRANULAR SOIL (SE—>30) TO BE OENSIFIED IN PLACE BY FLOODING DETAIL TYPICAL PROFILE ALONG WINDROW Rock with maximum dimensions greater than 6 inches should not be used within 10 feet vertically of finish grade (or 2 feet below depth of lowest utility whichever Is greater), and 15 feet horizontally of slope faces. Rocks with maximum dimensions greater than 4 feet should not be utilized in fills. Rock placement, flooding of granular soil, and fill placement should be observed by the geotechnical consultant. Maximum size and spacing of windrows should be in accordance with the above details Width of windrow should not exceed 4 feet. Windrows should be staggered vertically (as depicted). Rock should be placed in excavated trenches. Granular soil (S.E. greater than or equal to 30) should be flooded in the windrow to completely fill voids around and beneath rocks. APPENDIX C 0 ENGINEERING DESIGN GROUP PHONE: (760) 839-7302 FAX: (760) 480-7477 2121 MON11EL ROAD SAN MARCOS, CALFORNIA 92069 3% MIN SLOPE t'tfr1ll1J'1 WATEGffIP$ FEC!HCATiCN5 (NOT TO 9CALE) ®POAtI UV PROTECTION BOARD PER I P1ANLFACTUR'5 SPECIFICATION L ® GRACE PROCOR FLUID-APPLIED WTERPROOFM INSTALLED PER lu E 11ANLFACTUR'S SPECIFICATIONS 4 - 4u U EXTEND SEI4IND CETIENTITC'JS SACKER BOARD. 3 GRACE 1-IYDRODUCT 220 - INSTALLED PER t1AMFAC71JR'S SPECIFICATIONS OVER FLUID-APPLIED ROOFM TE1IN4TIGN SAR PER MANUFACTURER'S Z SPECIFICATIONS () FILTER FABRIC WI 6" MIN LAP () 3/4" GRAVEL (I SF / FT) 7 4" DIA PEW-ORATED DRAIN LINE (604 40 OR EQUIV) PEOR4TION5 ORIENTED DC(114 It t1INff1Lt1 GRADIENT TO SUITABLE OUTLET - EXACT PIPE LOCATION TO BE DETE1INE0 BY SITE CONSTRAINTS O 4" TALL CONCRETE CANT 0 FTG / W4LL CasMCTION (LNDER W4TEROCFII') SLOPE TO SACK EDGE OF POOTfr c'mc OR 1V - T UJAL.L PER PLAN 4 DETAILS I-rrDRoTlTE W4TER- STOPS AT COLD- JOINTS PER t INSTALLATION INS TJCT1N$ SLAB 4 VAPOR BARRIER PER PLAN 4 DETAILS ®COMPACTED SACKFILL WX MIN WLATIVE ' COMPACTION IN ALL OTIER AREAS UL 6" TIAX LIFTS. ONLY LIG-4TUEIGA4T "N40- OPERA TED EQUIPIENT SHALL BE USED UJININ 3 FEET OF ThE SACK FACE OF LLL4LL