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HomeMy WebLinkAboutPD 2018-0027; Gee Property; Updated Geotechnical Recommendations; 2020-06-25 (2)lftlE~Gl~EERING www.designgroupca.com Date: June 25, 2020 To: Chuck Gee 3800 Alder Avenue Carlsbad, CA 92008 Mo11tinl I (CO ll'.l'.l Re: New detached garage, located at 3800 Alder Avenue, Carlsbad, California GR2019-0035, DWG 520-3A Subject: Updated Geotechnical Recommendations References: 1. Notice of Violation, Case No. CC2019-0139, 3800 Alder Avenue, Carlsbad 2. "Limited Geotechnical Investigation and Foundation Recommendations for the Additions and Remodel to the Residence Located at 3800 Alder Avenue, Carlsbad, California," dated July 22, 2014, prepared by Engineering Design Group. 3. Grading Plan, Drawing No. 520-3A, prepared by Engineering Design Group. Per the redline review comments by the City of Carlsbad we have provided this report presenting geotechnical recommendations associated with the proposed new detention areas associated with the constructed driveway improvements. The earthwork recommendations and foundation design parameters presented in this report are based upon our original geotechnical report, as well as limited quality control conducted during the original addition described in the above report, Reference No. 2. If you have any questions regarding the following report, please do not hesitate to contact our office. Sincerely, ENGINEERING Steven Norris GE 2590 DESIGN GROUP Erin E. Rist RCE 65122 1.0 SCOPE This report gives our recommendations for the proposed new proposed detention areas to be located at 3800 Alder Avenue, Carlsbad, California. The scope of our work conducted onsite to date has included a visual reconnaissance of the property and surrounding areas, review of previous reports prepared by Engineering Design Group and preparation of this report presenting our findings, conclusions and recommendations. 2.0 SITE AND PROJECT DESCRIPTION The subject property is located at 3800 Alder Avenue, Carlsbad, California. Since the time of our previous report, the original additions, described as part of the scope of work in that report, was performed. Since the time of that report two additional detached garages and paved driveway at the rear of the property were constructed. Work associated with these improvements was not observed by Engineering Design Group. The area of proposed work associated with the recommendations provided herein are grading associated with the new rear detention areas, as well as soil design parameters for retaining walls. Specific soil design values are based upon previous investigation at the site and our experience in the area. 3.0 FIELD INVESTIGATION No additional field investigation was performed as part of this update. Representatives from our office have visited the site prior to the preparation of this report to confirm field conditions. 4.0 SUBSURFACE CONDITIONS As identified in our original reports we anticipated onsite soils will consist of topsoil/weathered material and fill, underlain by slightly silty sandstone. We anticipate these materials consist of light brown to brown, dry to slightly moist, medium dense to dense, slightly silty sands/sandstone. Slightly silty sands classify as SW-SM according to the Unified Classification System and based on visual observation generally possess potentials for expansion in the low range. 5.0 PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS In general, it is our opinion that the proposed new detention area improvements, as discussed and Gee Residence 3800 Alder Avenue, Carlsbad, California ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS Page No. 2 Job No. 196151-5 described herein, are feasible from a geotechnical standpoint, provided the recommendations of this report and all applicable codes are followed. 6.0 EARTHWORK We anticipate the creation of new fill slopes will be needed at the Bioretention Basin A and new retaining walls will be constructed at Bioretention Basin B. All grading shall be done in accordance with the recommendations below as well as Appendix B of this report and the standards of county and state agencies, as applicable. 6.1 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. Construction debris should not generally be mixed with soils to be utilized as new fill. Holes resulting from the removal of debris, existing structures, or other improvements, should be filled and compacted, per the methods described herein. 6.2 Removals In areas of new proposed improvements, competent material is anticipated 2-4 feet below existing grade. Grading should consist of the removal of unsuitable fill and weathered materials, ripping of subgrade and placement and re-compaction of fill material, (90 percent minimum relative compaction), in the area of the proposed new building pad subgrade. 6.3 Fills/Backfill All fill/backfill material 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 more than 6 inches in diameter (oversize material is not anticipated), 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. Imported soils should have a low potential for expansion (El<S0), free of debris, free of oversize material in excess of 6 inches in diameter and free of contamination (including organics). Prior to importing soils, they should be visually observed, sampled and tested at the borrow pit area to evaluate soil suitability as fill. Onsite excavated Gee Residence 3800 Alder Avenue, Carlsbad, California ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS Page No. 3 Job No. 196151-5 fill materials are not suitable for re-use as fill material in the upper 24 inches of pad subgrade. Utility trenches should be properly backfilled in accordance with the latest edition of Green Book standards. 6.4 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 slopes shall be constructed with standard slope grading construction standards, including establishing keyways into competent materials, canting keyways into slopes, and benching techniques. 1'.'\li 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). 7.0 RETAINING WALLS Retaining walls. For the purposes of permitting and design we have provided geotechnical design values for Keystone retaining walls, including proposed new retaining wall at the Bioretention Basin B, as well as Keystone walls below the easternmost detached garage, previously constructed by the project owner. 7.1 Keystone retaining wall foundations bearing uniformly in competent material may be designed utilizing maximum allowable soils pressure of 2,000 psf. 7.1 All retaining wall foundations are anticipated to be placed on competent material. Where cut-fill transitions may occur, alternative detailing, as necessary and determined in the field, may be provided by the Engineering Design Group on a case by case basis. 7.2 For the purposes of design and in consideration of the as-built conditions, Keystone retaining walls may be designed with an internal angle of friction 28 degrees for reinforced, retained and foundations zones. 7.3 Any other surcharge loadings shall be analyzed in addition to the above values. These surcharge loads shall include foundations, construction equipment, vehicular traffic, etc. 7.4 Retaining walls shall be designed for additional lateral forces due to earthquake, where required by code, utilizing the following design parameters. Gee Residence 3800 Alder Avenue, Carlsbad, California ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS Page No. 4 Job No. 196151-5 7.4.a. Where cantilevered or non-yielding retaining walls are proposed, the specific conditions should be brought to the attention of Engineering Design Group for alternative design values. 7.4.b. The unit weight of 120 pcf for the onsite soils may be utilized. 7.4.c. 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 Passive soil resistance-may be calculated using an equivalent fluid pressure of 275 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. 7.6 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 D. 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 anticipated basement levels, performance expectations and budget. 8.0 INFILTRATION In consideration of the location of the proposed detention relative to onsite slopes, the bottom of the detention basins shall be lined with an impervious barrier. Proper surface drainage and irrigation practices will play a significant role in the future performance of the project. 9.0 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. Gee Residence 3800 Alder Avenue, Carlsbad, California ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS Page No. 5 Job No. 196151-5 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 10 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 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. 10.0 CONSTRUCT/ON OBSERVATION AND TESTING The recommendations provided in this report are based on subsurface conditions disclosed by the our original 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). 10.1 Review offinal approved grading plans prior to the start of work for compliance with geotechnical recommendations. 10.2 Attendance of a pre-grade/construction meeting prior to the start of work. 10.3 Observation of subgrade and excavation bottoms. Gee Residence 3800 Alder Avenue, Carlsbad, California ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS Page No. 6 Job No. 196151-5 10.4 Testing of any fill placed, including retaining wall backfill and utility trench backfill. 10.5 Observation of footing excavations prior to steel placement and removal of excavation equipment. 10.6 Field observation of any "field change" condition involving soils. 10.7 Walk through offinal 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. 11.0 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 and subsurface observations at the site and knowledge of local conditions. The recommendations in this report are based on our experience in conjunction with the limited soils exposed at this site. 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 Gee Residence 3800 Alder Avenue, Carlsbad, California ENGINEERING DESIGN GROUP GEOTECHNICAL, CIV1L, STRUCTURAL CONSULTANTS Page No. 7 Job No.196151-1 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. In addition, changes in requirements due to state of the art knowledge and/or legislation are rapidly occurring. As a result, the findings ofthis 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. !tis the responsibility of the owner or his/her 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. Gee Residence 3800 Alder Avenue, Carlsbad, California ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS Page No. 8 Job No.196151-1 2121 Montiel Road, San Marcos, California 92069 • (760) 839-7302 • Fax: (760) 480-7477 • www.designgroupca.com LIMITED GEOTECHNICAL INVESTIGATION & FOUNDATION RECOMMENDATIONS FOR THE ADDITIONS & REMODEL TO THE RESIDENCE LOCATED AT 3800 ALDER AVENUE CARLSBAD, CALIFORNIA EDG Project No. 145327-5 July 22, 2014 PREPARED FOR: Chuck & Dee Ann Gee 3800 Alder Avenue Carlsbad, CA 92008 2121 Montiel Road, San Marcos, California 92069 • (760) 839-7302 • Fax: (760) 480-7477 • www.designgroupca.com Date: To: July 22, 2014 Chuck & Dee Ann Gee 3800 Alder Avenue Carlsbad, CA 92008 Re: Subject: Residence located at 3800 Alder Avenue, Carlsbad, California Geotechnical Investigation and Report In accordance with your request and our signed proposal, dated June 18, 2014, we have performed an investigation of site conditions in consideration of the proposed additions and remodel. The findings of the investigation, earthwork recommendations and foundation design parameters are presented in this report. In general it is our opinion 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 ------ Steven Norris California GE#2590 ------· Erin E. Rist California RCE #65122 TABLE OF CONTENTS Section 1 SCOPE ................................................................................. 1 2 SITE AND PROJECT DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 3 FIELD INVESTIGATION.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4 SUBSURFACE CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 5 GROUND WATER.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 6 LIQUEFACTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 7 CONCLUSIONS AND RECOMMENDATIONS ...................................................... 2 7.1 GENERAL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 7.2 EARTHWORK ......................................................................... 3 7.3 FOUNDATIONS ........................................................................ 4 7.4 CONCRETE SLABS ON GRADE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 7.5 RETAINING WALLS ..................................................................... 7 7.6 SURFACE DRAINAGE ................................................................... 9 8 CONSTRUCTION OBSERVATION AND TESTING ................................................... 8 9 MISCELLANEOUS.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 FIGURES Site Vicinity Map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure No. 1 Site Location Map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure No. 2 Test Pit Location Map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure No. 3 Test Pit Logs ................................................................... Test Pit Logs 1 to 2 APPENDICES References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Appendix A General Earthwork and Grading Specifications ............................................. Appendix B Laboratory Testing .................................................................... Appendix C 1 SCOPE This report gives our recommendations for the proposed remodel of the residence located at 3800 Alder Avenue, Carlsbad, California. (See Figure No. 1, "Site Vicinity Map", and Figure No. 2, "Site Location Map"). The scope of our work conducted onsite to date has included a visual reconnaissance of the property and surrounding areas, subsurface investigation, and preparation of this report presenting our findings, conclusions and recommendations. 2 SITE AND PROJECT DESCRIPTION For the purposes of this report the subject property generally faces west. The subject property is bordered to the north and south single family residences, to the east by El Camino Real and to the west by Alder Avenue. The subject property is currently developed with a one story single family residence with an attached garage. The general topography of the site area consists of foothill terrain. The topography of the site itself consists of a generally flat building pad at the residence, with variable slopes ranging between gentle to steep extending beyond the building pad to the steep cut slope at the eastern portion of the property which descends to El Camino Real below. In general the site descends from west to east. Based upon our review of the preliminary plans we understand that development will consist of two new additions at the rear of the existing residence and a general remodel to the existing residence. We further understand the new additions will consist of lower level partial subterranean structures. 3 FIELD INVEST/GA TION Our field investigation of the property consisted of a site reconnaissance, site field measurements, observation of existing conditions on-site and on adjacent sites, and a limited subsurface investigation of soil conditions. Our subsurface investigation consisted of visual observation of three exploratory test pit excavations in the front yard, rear yard, and south side yard along the building footing, logging of soil types encountered, and sampling of soils for laboratory testing. The locations of our test pits are given in Figure No. 3, "Test Pit Location Map". 4 SUBSURFACE CONDITIONS Based upon our subsurface field investigation and visual reconnaissance of the property soil types are described as follows: Topsoil / Fill/ Weathered Profiles: Topsoil, fill and weathered materials were exposed in our exploratory test pits extend to depths up to approximately 3.5 feet below adjacent grade in the area of our subsurface investigation. These materials consist of light brown to brown, dry to slightly moist, medium dense, slightly silty sands. These materials are not considered suitable for the support of structures and structural improvements, provided the recommendations of this report are followed. Slightly silty sands classify as SW-SM according to the Unified Classification System, and based on visual observation generally possess potentials for expansion in the low range. The existing footing was exposed and measured to extend approximately 12 inches below grade. GEE ADDITIONS 3800 Alder Avenue, Carlsbad, California ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS Page No.1 Job No. 145327-1 Sandstone: Sandstone was found to underlie the fil/weathered profiles within our test pit excavations. Sandstone consists of rust brown to grey, moist, dense, silty sands with clasts of clayey sands. These materials are considered suitable for the support of structures and structural improvements, provided the recommendations of this report are followed. Sandstone materials classify as SM-SC according to the Unified Soil Classification System, and based on visual observation and our experience, possess an expansion potential of low to medium. 5 GROUND WATER Static ground water was not encountered during our investigation to the depth investigated. Groundwater is not anticipated to pose any significant constraints to construction, however based upon our experience with stormwater infiltration, perched groundwater conditions can develop where no such condition previously existed In consideration of the subterranean portions of the proposed structure we recommend a waterproofing membrane below the subterranean slab. Waterproofing membrane shall be specifically detailed by waterproofing consultant. If groundwater conditions are encountered during site excavations, a slab underdrain systems may be required. 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. 6 LIQUEFACTION 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 clays 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. 7 CONCLUSIONS AND RECOMMENDATIONS 7.1 GENERAL In general it is our opinion the proposed construction, as discussed and described herein, is feasible from a GEE ADDITIONS 3800 Alder Avenue, Carlsbad, California ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS Page No. 2 Job No. 145327-1 geotechnical standpoint, provided the recommendations of this report are followed. Based upon our subsurface investigation we anticipate excavations in the area of new improvements up to 8 feet. We anticipate excavations made to subgrade on the east side of the new addition will not extend through weathered/fill profiles and therefore we recommend a removal and recompaction in the areas of proposed slab on grade floors in this area. Based upon site grades as proposed per the preliminary plans it appears excavations in the area of the new garage will generally extend through weathered profiles, to be confirmed in the field at the time of excavation. A rip and recompaction, as more specifically described below, is anticipated at the garage. 7.2 EARTHWORK Grading should be conducted in accordance 1,vith the recommendations below as well as Appendix B of this report, and standards of city, county and state agencies, as applicable. 7.2.1 Site Preparation Prior to any grading, the areas of proposed improvement 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 using onsite material or an import material with a very low potential for expansion. 7 .2.2 Removals Fill and weathered profiles found to mantle the site in our test pits, approximately the upper 3-3.5 feet as observed in the field, are not suitable for the structural support of buildings or structural improvements in their present state. We anticipate excavations on the east side of the proposed improvements will not extend through weathered/fill profiles and therefore we recommend a removal and recompaction in the areas of proposed slab on grade floors. In general grading should consist of the removal of unsuitable soil and scarification of subgrade to a minimum depth of 12 inches and the re-compaction of fill materials to 90 percent minimum relative compaction. Where new driveways are proposed, the upper 12 inches below adjacent grade shall be ripped and recompacted, as described herein and determined in the field by a representative of Engineering Design Group. Excavated fill materials are suitable for re-use as fill material during grading provided they are cleaned of debris and oversize material in excess of 6 inches in diameter (oversized material is not anticipated to be of significant concern) and are free of contamination. 7.2.3 Transitions Any structural sensitive improvements should be constructed on a uniform building pad. Removals and undercuts should extend a minimum of 5 feet (or to a distance at least equal to depth of fill removals, whichever is greater) beyond the footprint of the proposed structures and settlement sensitive improvements. Where this condition cannot be met it should be reviewed by the Engineering Design Group on a case by case basis. Removal depths should be visually verified by a representative of our firm prior to the placement of fill. Where new foundations extend outside of areas of slab on grade floors, new foundations may extend to competent sandstone. Transitions at these locations should be brought to the attention of Engineering Design Group and detailed on a case by case basis. GEE ADDITIONS 3800 Alder Avenue, Carlsbad, California ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS Page No. 3 Job No. 145327-1 7.2.4 Fills All fill in the area of removal and recompaction 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, oversize material in excess of 6 inches in diameter, brought to near optimum moisture content, and re-compacted to at least 90% relative compaction (based on ASTM D1557). Surficial, loose or soft soils exposed or encountered during grading (such as any undocumented or loose fill materials) should be removed to competent material and properly compacted prior to additional fill placement. Fills should generally be placed in lifts not exceeding 6-8 inches in thickness. If the import of soil is planned, soils should have a low potential for expansion (El<S0), free of debris and organic matter. Prior to importing soils should be visually observed, sampled and tested at the borrow pit area to evaluate soil suitability as fill 7 .2.5 Slopes 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 structures or properties without proper shoring. 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). 7.3 FOUNDATIONS The following design parameters may be utilized for new foundations founded on competent recompacted fill material or competent sandstone. 7.3.1 Footings bearing in competent material or recompacted fill material may be designed utilizing maximum allowable soils pressure of 2,000 psf. 7.3.2 Seismic Design Parameters Site Class D Spectral Response Coefficients SMS (g) 1.171 SMl (g) 0.671 Sos (g) 0.781 Sm (g) 0.447 7.3.3 Bearing values may be increased by 33% when considering wind, seismic, or other short duration loadings. GEE ADDITIONS 3800 Alder Avenue, Carlsbad, California ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS Page No. 4 Job No. 145327-1 7.3.4 The parameters in the table below should be used as a minimum for designing new footing width and depth below lowest adjacent grade. Footing depths 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 7.3.5 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. 7.3.6 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. 7.3.7 For footings adjacent to slopes a minimum of 12 feet (competent material) and horizontal setback in competent material or properly compacted fill should be maintained. All slope setbacks above the oversteepened cut slope at the driveway should be taken based upon a project 2:1 slope from the existing toe. A setback measurement should be taken at the horizontal distance from the bottom of the footing to slope daylight. Where this condition can not be met it should be brought to the attention of the Engineering Design Group for review. 7.3.8 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. 7.3.9 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. 7.3.10 All new stem walls shall extend a minimum of 6 inches above grade and in compliance with building codes. 7.4 CONCRETE SLABS ON GRADE All new concrete slab on grade floors should be placed on recompacted fill material or competent sandstone, shall use the following as the minimum design parameters. 7.4.1 Concrete slabs on grade of the building and garage 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. • Slump: Between 3 and 4 inches maximum • Aggregate Size: 3/4 -1 inch • Moisture Sensitive Areas: (i.e. floors, below grade walls) Water to cement Ratio -0.45 maximum GEE ADDITIONS 3800 Alder Avenue, Carlsbad, California ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS Page No. 5 Job No. 145327-1 Compressive Strength " 4,500 psi minimum (No special inspection required for water to cement ratio purposes, unless otherwise specified by the structural engineer) • Moisture retarding additive: in concrete at concrete slab on grade floors and moisture sensitive areas. • Non-Moisture Sensitive Areas: Compressive Strength= 2,500 psi minimum. 7.4.2 In moisture sensitive areas, the slab concrete should have a minimum water to cement (w/c) ratio of 0.45, generally resulting in a compressive strength of approximately 4,500 psi (No special inspection required for water to cement ratio purposes, unless otherwise specified by the structural engineer) as determined by the w/c ratio. This recommendation is intended to achieve a low permeability concrete. 7.4.3 In consideration of the subterranean portions of the proposed structures we recommend a waterproofing membrane below the subterranean slab. Waterproofing membrane shall be specifically detailed by waterproofing consultant. 7.4.4 The project architect and/or waterproofing consultant should provide all slab underdrain, flooring sealers and various other details, specifications and recommendations (i.e Moiststop and Linkseal) at areas of potential moisture intrusion (i.e. basement slabs and slab penetrations). Engineering Design Group accepts no responsibility for design or quality control of waterproofing elements of the building. 7.4.5 All required fills used to support slabs, should be placed in accordance with the grading section of this report and the attached Appendix B, and compacted to 90 percent Modified Proctor Density, ASTM D-1557, and as described in the Earthwork section of this report. 7.4.6 In general 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 waterproof membrane. There shall be not greater than a ½ inch difference across the sand layer. Beneath the membrane we recommend uniform layer of 3 inches of pea gravel in order to more uniformly support the slab, help distribute loads to the soils beneath the slab, and act as a capillary break. This detailig shall be confirmed with slab waterproof detail recommended by waterproofing consultant/architect. 7.4.7 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. 7.4.8 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. 7.4.9 Exterior concrete flatwork and driveway slabs, 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 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 GEE ADDITIONS 3800 Alder Avenue, Carlsbad, California ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS Page No. 6 Job No. 145327-1 should be a minimum of 2% over optimum moisture to a depth of 18 inches. • Concrete may be poured with a 10 inch deep thickened edge. Flatwork adjacent to top of a slope should be constructed with a outside footing to attain a minimum of 7 feet distance to daylight. • Concrete should be constructed with tooled joints or sawcuts (1 inch deep) 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 flatwork is adjacent to concrete foundations or other structures and improvements. • 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 New retaining walls may be designed and constructed up to 10 feet in accordance with the following recommendations and minimum design parameters. 7.5.1 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 "Foundations" section of this report. It is anticipated that all retaining wall footings will be placed on competent material. Where cut-fill transitions may occur footings may be deepened to competent material and alternative detailing may be provided by the Engineering Design Group on a case by case basis. 7.5.2 In moisture sensitive areas (i.e. interior living space where vapor emission is a concern), we recommend any building retaining walls be designed as poured in place concrete in lieu of masonry to limit vapor emissions. 7.5.3 Unrestrained cantilever retaining walls should be designed using an active equivalent fluid pressure of 40 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.1. >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 soil are not anticipated to be used in project backfill zones without additional testing of expansion potential. For sloping backfill, the following parameters may be utilized: Backfill Sloping Condition 2:1 Slope Active Fluid Pressure 50 pcf GEE ADDITIONS 3800 Alder Avenue, Carlsbad, California ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 1.5:1 Slope 65 pcf Page No. 7 Job No. 145327-1 Any other surcharge loadings shall be analyzed in addition to the above values. 7.5.4 If the tops of retaining walls are restrained from movement, they should be designed for an uniform at- rest soil pressure of 65 psf. 7.5.5 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 ('{) 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 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. 7.5.6 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. 7.5.7 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. 7.5.8 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. 7.5.9 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. 7.5.10 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. 7.6 SURFACE DRAINAGE Adequate drainage precautions at this site are imperative and will play a critical role on the future performance GEE ADDITIONS 3800 Alder Avenue, Carlsbad, California ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS Page No. 8 Job No. 145327-1 of the dwelling and improvements. Under no circumstances should water be allowed to pond against or adjacent to foundation walls, or tops of slopes. 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 to accommodate runoff and avoid any ponding of water. Area drain inlets shall be located at low points to accommodate runoff. 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. 8 CONSTRUCT/ON 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). 8.1 Review of final approved grading and structural plans prior to the start of work for compliance with geotechnical recommendations. 8.2 Attendance of a pre-grade/construction meeting prior to the start of work. 8.3 Observation of subgrade, excavation bottoms. 8.4 Testing of any fill placed, including retaining wall backfill and utility trenches. 8.5 Observation of footing excavations prior to steel placement and removal of excavation equipment. 8.6 Field observation of any "field change" condition involving soils. 8.7 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. GEE ADDITIONS 3800 Alder Avenue, Carlsbad, California ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS Page No. 9 Job No. 145327-1 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. 9 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 visual observation of the soils exposed in the exploratory test pits. The recommendations in this report are based on our experience in conjunction with the limited soils exposed at this site and our review of limited grading plans. As noted Engineering Design Group relied upon certifications associated with original grading and conducted additional investigation and testing only as noted. We believe that this information gives an acceptable degree of reliability for anticipating the behavior of the proposed structure; 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. GEE ADDITIONS 3800 Alder Avenue, Carlsbad, California ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS Page No. 10 Job No. 145327-1 FIGURES E1'TGINEE~TG DESIGN GROUP GECTECPM-C .. L. 0~ & STFiUCT\HlAL cc-,=u~tAm:;;. rcn fl[=:ot:NTIAL II, r:m,.orc~r.1At COtCJfll.lCT!ON: 2121 Montiel Road. San Marcos, California 92069 -(760) 839-7302 -Fax: (760) 480-7477 -www.designgroupca.com ,,.,,_ Project: GEE Address: 3800 Alder Ave., Carlsbad, CA EDG Project No: 145313-1 FIGURE 1 Vicinity Map E1'TGThTEERThTG DESIGN GROUP GEDIECt-,11',;CA.L. 01(' ..... & S.TflUCTIJFlAL cc:•1::uL1Am~ IC!'! "l=·nct-111 .. L .. cm,,11up1r:1At COt&:lf1tJC110~ '-~~ 2121 Montiel Road. San Marcos. California 92069 • (760) 839-7302 • Fax: (760) 480-7477 • www.designgroupca.com Project: GEE Address: 3800 Alder Ave., Carlsbad, CA EDr-0 roject No: 145313-1 FIGURE 2 Site Mc>·- ENGrnEE~TG DESIGN GROUP GECJEC-Ptr,CA.L. t:IV:---& STF\UCTURAL cc•1:;.ur,111.m:;. It:!'! nt: OCNTl"L,. cnM11Enr:mt crm:rnr.n:nrm 2121 Montiel Road. San Marcos, California 92069 • (760) 839-7302 • Fax: (760) 480-7477 • www.designgroupca.com ¾. Project: GEE Address: 3800 Alder Ave., Carlsbad, CA EDG Project No: 145313-1 FIGURE 3 Approximate Test Pit Locations Project Na GEE I TEST PIT LG ,o. 1 EDG Project 145327-1 Number: Location: 15 ft. east of rear of existing residence, approximately 40 Sheet 1 of 1 feet south of north fence Date{s) 7-18-14 Total Depth: 4.5' Groundwater No Excavated: Level: Logged By: EER/VRE Approx. Surface 293 Backfilled 7-18-14 Elev. (date) Excavation Hand Excavated Method: Soil Type Depth Material Description and Notes ucsc Sample A Oto 3.5' TOPSOIL/WEATHERED/FILL: SW-SM Light to rust brown, dry to slightly moist, medium dense, slightly silty sands. B 3.5' to 4.5' SANDSTONE: SW-SC Rust brown to grey, moist, dense, slightly silty sandstone to small clayey sand clasts. GRAPHIC REPRESENTATION: FG l11 Z, IVl) _: · _. : vl/lZ:&Vl -1 - I -.. ® .· . -2 ' -. . '\ ~ \ -3 I . . . -4 /·.>--.. • b:fBb·--....-r ~•.-c·:~) ..... _ .. -·: ... · . -5 -6 -7 -8 -9 Project Name: GEE TEST PIT LOG NO. 2 EDG Project 145327-1 Number: Location: 15 ft. east of rear of existing residence, approximately 40 Sheet 1 of 1 feet south of north fence Date(s) 7-18-14 Total Depth: 2.5' Groundwater No Excavated: Level: Logged By: EERNRE Approx. Surface 295 Backfilled 7-18-14 Elev. (date) Excavation Hand Excavated Method: Soil Type Depth Material Description and Notes ucsc Sample A Oto 1.5' TOPSOIL/WEATHERED/FILL: SW-SM light brown to brown, dry, medium dense, slightly silty sands. B 1.5' to 2.5' SANDSTONE: SW-SM Rust brown, moist, dense, slightly silty sands. GRAPHIC REPRESENTATION: FG liV\--Z:,,.-Lv1,2\ : : , .1J\'\ .• .:.. _· / lV~l~ -1 ''I -,·\nJ ~.·I I --~ r l ·• "' -r •,•.~'I -2 '-' " · ' ' . ,. ( °F-, I ·! -3 lSJ -4 -5 -6 -7 -8 -9 APPENDIX A REFERENCES 1. California Geological Survey, Probabilistic Seismic Hazards Mapping Ground Motion Page. 2. California Department of Conservation, Division of Mines and Geology, Fault Rupture Zones in California, Special Publication 42, Revised 1990. 3. Day, Robert W. 1999. Geotechnical and Foundation Engineering Design and Construction. McGraw Hill. 4. Engineering Design Group, unpublished in house data. 5. Greensfelder, R.W., 1974 Maximum Credible Rock Acceleration from Earthquakes in California Division of Mines and Geology, Map Sheet 23. 6. 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. 7. Newmark sliding block analysis, Report 5, Miscellaneous Paper, S 71-17, U.S. Army Corp of Engineers, Waterways Experiment Station, Vickburg, Mississippi." 8. Ploessel, M.R. and Slossan, J.E., 1974 Repeatable High Ground Acceleration from Earthquakes: California Geology, Vol. 27, No. 9, P. 195-199. 9. State of California, Fault Map of California, Map No. 1, Dated 1975. 10. State of California, Geologic Map of California, Map No. 1, Dated 1977. 11. Structural Engineers Association of Southern California (SEAOSC) Seismology Committee, Macroseminar Presentation on Seismically Induced Earth Pressure, June 8, 2006. 12. Tian, Siang T. and Kennedy, Michael P., Geology of the Oceanside, San Luis Rey, San Marcos 7.5' Quadrangle San Diego County, California, dated 1996. 13. 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 14. 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. 15. 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. 16. Various Aerial Photographs. 17. Wright Design, Gee Renovation, Proposed Lower Floor Plan, undated. APPENDIX B General Earthwork and Grading Specifications 1.0 General Intent 2.0 3.0 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. 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 01557. 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 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 5.0 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. 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 I 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 FINISHED SLOPE FACE PROJECT 1 TO 1 LINE FROM TOP OF SLOPE TO OUTSIDE EDGE OF KEY OVERBURDEN OR UNSUITABLE MATERIAL I • EXISTING GROUND ----- SURFACE\ . .,,..,.... --.,,.....- ~ /// / ./ ,,,,,...,,,,,....,,.,.,,., FINISHED CUT PAO ( COMPETENT BEDROCK OR MATERIAL AS EVALU~TEO BY THE QEOTECHNICAL CONSULTANT I I NOTE: Subdrain details and key width recommendations to be provided based on expos ad sub surf ace conditions STABILITY FILL / BUTTRESS DETAIL KEY 2 ~11 1 MIN. f FILTER FABRIC ENVELOPE (MIAAFI 140N OR APPROVED EQUIVALENT>* OUTLET PIPES -4" ti NONP&RFORATED PIPE, 100' MAX. O.C. HORIZONTALLY, 30' MAX. 0.C. VERTICALL V SEE T-CONNECTION DETAIL SUBDRAIN TRENCH DETAIL NOTES: SEE SUBDRAIN TRENCH DETAIL LOWEST SUBDAAIN SHOULD BE SITUATED AS LOW AS POSSIBLE TO ALLOW SUITABLE OUTLET ~ 1 O' MIN. PERFORATED L-i__J EACH SIDE PIPE~ CAP NON-PERFORATED OUTLET PIPE T-CO.NNECTION DETAIL * IF CAL TRANS 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 % Passing l" 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>7S For buttress dimensions, see geotechnical report/plans. Actual dimensions of buttress and eubdrain ma~ be changed by the geotechnlcal consultant based on field conditions. SUBDRAIN INSTAL.LATION-Subdraln pipe should be Installed with perforations down as depicted, At locations recommended by the geotechnical consultant, nonperforated pipe should be Installed SUBOAAIN TVPE-Subdraln type should be Acryton trite Butadiene Styrene (A.S.S.), Polyvinyl Chloride (PVC) or approved equivalent. Claaa 125,SOR 32,S should be uaed for maximum flll depths of 35 feet. Clau 2009 SOR 21 ehould be used tor maximum fill depth11 of 100 feet. KEY AND BENCHING DETAILS FILL SLOPE PROJli!CT 1 TO 1 LINE EXIST1NG QAOUND SURFACE r;, MIN.L~5• MIN.----J KEV ILOWEST--7 DEPTH BENCH (KEY) FILL-OVER-CUT SLOPE CUT SLOPE (TO BE EXCAVATED PRIOR TO FILL PLACEMENT) //~ CUT-OVER-FILL SLOPE PROJECT 1 TO 1 LINE FROM TOE OF SLOPE TO COMPETENT MATERIAL EXISTING / / GROUND / / SURFACE~// ,g // ?='\~? / t '-\'"' / CUT SLOPt: (TO BE EXCAVATED PRIOR TO FILL PLACEMENT) NOTE: Back drain may be recommended by the geotechnical consultant based on actual field conditions encountered. Bench dimension recommendations may also be altered baaed on field conditions encountered. ROCK DISPOSAL DETAIL PINlaH GIIADE DETAIL --------------------------------------------------------------r□-r1-~~ r j(JL J\ -----=----__ _,,,_ ------------------------------------------------------- TYPICAL PROFILE ALONG WINDROW 1) 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, 2) Rocks with maximum dimensions greater than 4 feet should not be utilized in fills. 3) Rock placement, flooding of granular soil, and fill placement should be observed by the geotechnical consultant. · 4) Maximum sb:e 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). 5) 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 LABORATORY TESTING PROCEDURES Moisture and Density Tests: Moisture content and dry density determinations were performed on relatively undisturbed samples obtained from the test borings and/or trenches. The results of these tests are presented in the boring and/or trench logs. Where applicable, only moisture content was determined from "undisturbed" or disturbed samples. · . . . · ·. . . Classification Tests: Typical materials were subjected to mechanical grain-size analysis by wet sieving from U. s. Standard brass screens (ASTM 0422-65). Hydrometer analyses were performed where appreciable quantities of fines were encountered. The data was evaluate~ in determining the classification of the materials. The grain-size distribtition curves are presented in the test data and the Unified Soil Classification is presented in both the test data and the boring and/or trench logs. · Atterberg Limits,: The Atterberg Limits were determined in accordance with ASTM D4318-84 for engineering classification of the fine-grained materia.ls. Direct Shear Tests: Direct shear tests were performed on selected remolded and/or undisturbed samples which were soaked for a minimum of 24 hours under a surcharge equal to the applied normal force during testing. After transfer of the sample to the shear box, and reloading the sample, pore pressures set up in the sample due to the transfer were allowed to dissipate for a period of approximately I hour prior to application of shearing force. The samples were tested under various normal loads, a different specimen being used for each normal load. The samples were sheared in a motor-driven, strain-controlled, direct-shear testing apparatus at a strain rate of 0.05 inch per minute. After a travel of 0.300 inch of the direct shear machine, the motor was stopped and the sample was allowed to "relax" for approximately 15 minutes. The "relaxed" and "peak" shear values were recorded, It is anticipated that, in a majority of samples tested, the 15 minutes relaxing of the sample is sufficient to allow dissipation of pore pressures set up in the samples due to application of shearing force. The relaxed values are therefore judged to be a g.ood estimation of effective strength parameters. The test results were plotted on the «Direct Shear Summary". For residual direct shear test, the samples were sheared, as described in the preceding paragraph, with the rate of shearing of 0.001 inch per minute. The upper portion of the specimen was pulled back to the original position and the shearing process was repeat~d until no further decrease in shear strength was observed with continued shearing {at least three times resheared), There are two methods to obtain the shear values: (a) the shearing process was repeated for each normal load applied and the shear value for each normal load was recorded. One or more than one specimen can be used in this method; (b) only one specimen was needed, and a very high normal load (approximately 9000 psf) was applied from the beginning of the shearing process. After the equilibrium state was reached (after "relaxed"), the shear value for that normal load was recorded. The normal loads were then reduced gradually without shearing the sample (the motor was stopped). The shear values were recorded for different normal loads after they were reduced and the sample was "relaxed". 3040 689 Maximym Density Tests: The maximum dry density and optimum moisture content of typical materials were determined in accordance with ASTM D1557-78 (five layers). The results of these tests are presented in the test data. Expansion Index Iests: The expansion potential of selected materials was evaluated by the Expansion Index Test, U,B.C. Standard No. 29-2. Specimens are molded under a given compactive energy to approximately the optimum moisture content and approximately 50 percent saturation or approximately 90 percent relative compaction. The prepared )-inch thick by 4-.inch .diameter specimens are loaded to an equivalent 144 psf stircharge and are inundated with tap water until volumetric equilibrium is reached. The results of these tests are presented in the test data. Consolidation Tests: Consolidation tests were performed on selected, relatively undisturbed samples recovered from the sampler. Samples were placed in a con sol i dometer and loads were applied in geometric progression. The percent consolidation for each load cycle was recorded as the ratio of the amount of vertical compression to the original I-inch height. The consolidation pressure curves are presented in the test data. Where applicable, time-rates of consolidation were also recorded. A plot of these rates can be used to estimate time of consolidation. Soluble Sulfates: The soluble sulfate contents of selected samples were determined by the California Materials Method No. 417. "R"-Va]ue: The resistance "R"-value was determined by the California Materials Method No. 301 for base, subbase, and basement soils. Three samples were prepared and exudation pressure and 11 R11 -value determined on each one. The graphically determined 11 R"-value at exudation pressure of 300 psi is reported. Triaxial Compression Test§: Triaxial compression tests were performed on selected remolded and/or undisturbed samples according to ASTM 2166-85 (unconfined) and ASlM 2850-87 (confined). 3040 689 A PENDi D ENGINEERING DESIGN GROUP 2121 MONTIEL ROAD PHONE: (760) 839-7302 SAN MARCOS, CALIFORNIA 92069 FAX: {760) 480-74n CONC OR CHU--------.L--,,,__,.'-,l'll RET WALL PER PLAN 4 DETAILS I-IYOROTITE WATER- STOPS AT COLD- JOINTS PER MFR INSTALLATION INSTRUCTIONS SLA/3 4 VAPOR BARRIER PER PLAN 4 DETAILS MINIMUM WATERPROOFING, SPECIFICATIONS (NOT TO SCALE) CD FOAM UV PROTECTION SOARO PER MANUFACTURER'S SPECIFICATION (?) GRACE PROCOR FLUID-APPLIED '-J' WAiERFROOFi1'U ir45iALLED FER MANUFACTURER'S SPECIFICATIONS 4 EXTEND SEI-IIND CEMENTITOUS SACKER SOARO. ® @ (J) @ @ GRACE I-IYDRODUCT 22(!) INSTALLED PER MANUFACTURER'S SPECIFICATIONS OVER FLUID-APPLIED WATERPROOFING TEFNINATION SAR PER MANUFACTURER'S SPECIFICATIONS ---------' FILTER FABRIC WI b" MIN LAP 314" GRAVEL (I SF I FT) 4" DIA PEFcFORATED DRAIN LINE ($C/-l 4(!) OR EQUIV.) PERFORATIONS ORIENTED DOILN I% MINIMUM GRADIENT TO SUIT ASLE OUTLET - EXACT PIPE LOCATION TO SE DETEFNINED SY SITE CONSTRAINTS 4" TALL CONCRETE CANT• FTG I WALL CONNECTION (UNDER WA TERPROOFINGJ. SLOPE TO SACK. EDGE OF FOOTING. COMPACTED SACK.FILL W% MIN RELATIVE COMPACTION IN ALL OTI-IER AREAS U.ON. b" MAX LIFTS. ONLY LIGI-ITWEIGI-IT /-/ANO-OPERATED EQUIPMENT 51-/ALL SE U5ED WITI-IIN 3 FEET OF Tl-IE SACI< FACE OF WALL.