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HomeMy WebLinkAboutCDP 12-02; MAGNOLIA AVENUE RESIDENCE 2; GEOTECHNICAL INVESTIGATION AND FOUNDATION RECOMMENDATIONS; 2012-03-21C' 12 .o. ADVANCED GEOTECUINICAL SOLUTIONS, INC. 5333 Mission Center Road, Suite 390 San Diego, California 92108 Telephone: (619) 708-1649 Fax: (714) 409-3287 NEW POINTE COMMUNITIES, INC. 16880 West Bernardo Drive, Suite 230 San Diego, CA 92127 Attention: Mr. Scot Sandstrom March 21, 2012 P1W 1201-02 Report No 1201-02-B-2 Subject: Geotechnical Investigation and Foundation Design Recommendations for Proposed Single-Family Residences, Parcel 2 and 3, 1369 Magnolia Avenue, Carlsbad, California Gentlemen: In accordance with your request, presented herein are the results of Advanced Geotechnical Solutions, Inc.'s (AGS) geotechnical investigation and foundation design recommendations for the two proposed single-family residences at 1369 Magnolia Avenue, Carlsbad, California. The recommendations presented in the following report are based on a limited subsurface investigation - performed by AGS, review of the referenced geotechnical investigation report prepared by Construction and Testing Engineers, Inc. (CTE) and associated laboratory testing. It is AGS's opinion, from a geotechnical standpoint, the subject site is suitable for construction of the proposed residences, provided - the recommendations presented in this report are incorporated into the design, planning and construction phases of site development. Included in this report are: 1) engineering characteristics of the onsite soils; 2) unsuitable soil removal recommendations; 3) grading recommendations; 4) foundation design - recommendations; and 5) flatwork recommendations. Advanced Geotechnical Solutions, Inc., appreciates the opportunity to provide you with geotechnical consulting services and professional opinions. If you have any questions, please contact the undersigned at (619) 708-1649. Respectfully Submitted, - Advanced Geotechnical Solutions, -. 231 4 -OX 7FC~A JEFFREY A. CHANEY, Vice Pre' 5 F c RCE 46544/GE 2314, Reg. Exp. 6-301-i - No. 2536 -IERTIFIED L ENGINEERING S GEOLOGIST S E 5131/,j CA PAUL J. DERISI, Vice President CEG 2536, Reg. Exp. 5-31-13 Distribution: (5) Addressee Attachments: Figure 1 - Site Location Map Figure 2— Geologic Map and Site Exploration Plan; Appendix A - Field and Laboratory Data; Appendix B - General Earthwork Specifications & Grading Guidelines; Appendix C - Homeowner Maintenance Recommendations ORANGE AND L.A. COUNTIES INLAND EMPIRE SAN DIEGO AND IMPERIAL COUNTIES (714) 786-5661 (619) 708-1649 (619) 850-3980 March 21, 2012 Page 1 P1W 1201-02 Report No. 1201-02-B-2 1.0 SCOPE OF SERVICES. This study is aimed at providing geotechnical information as it relates to: 1) existing site soil conditions; 2) discussion of the geologic units onsite; 3) seismic hazard analysis; 4) engineering characteristics of the onsite soils; 5) excavation characteristics of earth materials; 6) seismic design parameters for use in the structural design of the proposed single family residence; and 7) foundation design parameters for the proposed conventional shallow foundation system. - The scope of our study included the following tasks: Review of pertinent published and unpublished geologic and geotechnical literature, maps, and - aerial photographs. > Excavating and logging two (2) shallow hand auger borings (Appendix A) > Conducting a geotechnical engineering and geologic hazard analysis of the site. > Conducting a limited seismicity analysis. Determine design parameters of onsite soils as a foundation medium including bearing and friction values for foundation soils. > Determine the site-specific seismic design parameters for use in the structural design. Preparation of a geotechnical foundation investigation report with exhibits summarizing our findings. This report would be suitable for design, contractor bidding, and regulatory review. 2.0 GEOTECHNICAL STUDY LIMITATIONS The conclusions and recommendations in this report are professional opinions based on our review of the - previously conducted geotechnical investigation (CTh, 2007), associated lab testing, and the data developed during this investigation. The materials immediately adjacent to or beneath those observed may have different characteristics than those observed. No representations are made as to the quality or extent of materials not observed. Any evaluation regarding the presence or absence of hazardous material is beyond the scope of this firm's - services. 3.0 SITE LOCATION AND DESCRIPTION - The subject site is located at 1369 Magnolia Avenue, Carlsbad, California (see Figure 1). The site is bounded to the north by Magnolia Avenue, and to the east, west, and south by existing residential properties. The roughly rectangular-shaped site is approximately 330 feet long and 140 feet wide, encompassing approximately 0.82 acre. The overall site is sub-divided into three parcels. Parcel 1, located in the northern portion of the site adjacent to Magnolia Avenue, is currently occupied by an existing - single-family residence. Site topography is relatively flat to gently sloping to the west. Current elevations at the site range from approximately 160 msl along the easterly property boundary to 151 feet msl at the westerly property ADVANCED GEOTECUINICAL SOt IJUONS, INC. March 21, 2012 Page 2 P1W 1201-02 Report No. 1201-02-B-2 boundary. The site contains scattered mature trees and is covered with a light growth of seasonal grasses and weeds. Localized trash and construction debris were also observed on site. 4.0 PROPOSED DEVELOPMENT - As we understand the proposed development, parcels 2 and 3 will be graded to create relatively flat building pads which will support the proposed single-family residences and associated improvements. The parcels are currently designed with cuts and fills on the order of 3 to 4 feet. The proposed residential - structures will be approximately 3,000 square feet, two-stories in height, wood-framed, and supported by a conventional shallow slab-on-grade foundation system. The structures will be surrounded by associated flatwork and landscaping. A private driveway is planned along the westerly property line to provide - access to the new residences. A four to six foot high retaining wall will also be constructed along the westerly property line to support the proposed driveway and a freestanding sound wall. 5.0 FIELD AND LABORATORY INVESTIGATION 5.1. Field Investigation - Previously, CTE (2007) conducted a subsurface investigation to evaluate the onsite soil and bedrock conditions. Six (6) test pits were excavated and logged to depths of six (6) feet below existing grades. Bulk soil samples were collected from the exploratory test pits for laboratory - testing. Logs of CTE's test pits and results of the associated laboratory testing are presented in Appendix A. - In addition, AGS conducted a limited subsurface exploration at the subject on March 16, 2012. Two hand auger borings were excavated at the subject site. The approximate locations of the borings are shown on Figure 2. The excavations were advanced to a maximum depth of 3.5 feet - below existing grades. 6.0 ENGINEERING GEOLOGY 6.1. Geologic and Geomorphic Setting The subject site is situated within the Peninsular Ranges Geomorphic Province. The Peninsular - Ranges province occupies the southwestern portion of California and extends southward to the southern tip of Baja California. In general the province consists of young, steeply sloped, northwest trending mountain ranges underlain by metamorphosed Late Jurassic to Early - Cretaceous-aged extrusive volcanic rock and Cretaceous-aged igneous plutonic rock of the Peninsular Ranges Batholith. The westernmost portion of the province is predominantly underlain by younger marine and non-marine sedimentary rocks. The Peninsular Ranges' dominant structural feature is northwest-southeast trending crustal blocks bounded by active faults of the San Andreas transform system. 6.2. Subsurface Conditions A brief description of the earth materials encountered on this site is presented in the following - sections. More detailed descriptions of these materials are provided in the hand auger logs included in Appendix A. Based on our site reconnaissance, subsurface excavations, and review of ADVANCED GEOTECIINICAI. SOLUTIONS, INC. March 21, 2012 Page 3 P1W 1201-02 Report No. 1.201-02-B-2 the referenced geotechnical investigation and geologic maps, the site is underlain to the depths explored by old paralic deposits (marine terrace. deposits) which are locally overlain by a thin veneer of topsoil/residual soils (undifferentiated). Although not encountered during our site exploration, localized undocumented fill soils were observed during CTE's investigation (2007) and may be present at the site. 6.2.1. Topsoil/Residual Soil (undifferentiated) Undifferentiated topsoil/residual soils were encountered in both onsite excavations and observed to overlie the old paralic deposits. These soils were of variable thickness, ranging from approximately 3.0 feet in boring HA-1 to 2.5 feet in HA-2. As encountered, these materials - generally consisted of light gray brown to reddish brown, moist, loose to medium dense, silty to clayey fine- to medium-grained sand. - 6.2.2. Old Paralic Deposits, Units 24 The site is underlain to maximum depth explored by Old Pamlic Deposits, Units 2-4. These materials can generally be described as mottled gray brown to reddish brown, slightly moist to moist, medium dense to. dense, silty fine to medium grained sand. 63. Groundwater - Groundwater was not encountered in our exploratory excavations. No natural groundwater condition is known, to exist at the site that would impact the proposed site development. However, it should be noted that localized perched groundwater may develop at a later date, most likely at or near fill/bedrock contacts, due to fluctuations in precipitation, irrigation practices, or factors not-evident at the time of our field explorations. 6.4. Non-seismic Geologic Hazards 6.4.1. Mass Wasting No evidence of mass wasting was observed onsite nor was any noted on the reviewed maps. - 6.4.2. Flooding According to available FEMA maps, the site is not in a FEMA identified flood hazard area. 6.43. Subsidence/Ground Fissuring Due to the presence of the dense underlying materials, the potential for subsidence and ground fissuring due to settlement is unlikely. 6.5. Seismic Hazards - The site is located in the tectonically active Southern California area, and will therefore likely experience shaking effects from earthquakes. The type and severity of seismic hazards affecting the site are to a large degree dependent upon the distance to the causative fault, the intensity of - the seismic event, and the underlying soil characteristics. The seismic hazard may be primary, such as surface rupture and/or ground shaking, or secondary, such as liquefaction or dynamic ADVANCED GEO1ECHNICAE. SOLIJIIONS, INC. 'March 21,2012 Pa-e-& P1W 1201-02 Report No. 1201-02-B-2 settlement The following is a site-specific discussion of ground motion parameters, earthquake- induced landslide hazards, settlement, and liquefaction The purpose of this analysis is to identify potential seismic hazards and proose mitigations, if necessary, to reduce the hazard to an acceptable level of risk The following seismic hazards discussion is guided by the California Building Code (2010), CDMG (2008), andMIrtin and Lew 19 918).' 65.1. Surface, Fault Rupture 0 No known active faults have been mapped at or near the subject site The nearest known active surface fault is the Oceanside section of the Newport-Inglewood-Rose Canyon fault zone which is approximately 5 miles west of the subject site Accordingly, the potential for fault surface rupture on the subject site is low This conclusion is based on literature review and aerial photographic analysis. 6.5.2. Seismicity S As noted, the site is within the tectonically active southern California area, and is approximately 5 miles from an active fault, the Oceanside section of the Newport-Inglewood-Rose Canyon fault zone The potential exists for strong ground motion that may affect future Improvements At this point in time, non-critical structures (commercial, residential, and industrial) are usually designed according to the California Building Code (2010) and that of the controlling local agency. However, liquefaction/seismic slope stability analyses, critical structures, water tanks and unusual structural designs will likely require site sp'ecific ground motion input. 6.5.3 Liquefaction Due to the densenature of the underlying materials and lack ofâ shallow groundwater-table at the project site, the potential for seismically induced liquefaction is considered negligible. 6.5.4. Dynamic Settlement Dynamic settlement occurs in response to an earthquake event in loose sandy earth materials This potential of dynamic settlement at the subject site is considered remote due to the presence of shallow marine terrace/bedrock andthe absence of loose, sandy soils. 65.5. Seismically lEnd uced Landsliding Evidence of landsliding at the site was not observed during our field explorations nor was any geomorphic features indicative of landsliding noted during our review of aerial photos and published geologic maps. 0 ADVANCED 6E01ECIONICAL SOLISIIONS, INC. March 21, 2012 Page 6 P1W 1201-02 Report No. 1201-02-B-2 - 7.1.6. Chemical/Resistivity Test Results Preliminary soluble sulfate and chloride, and resistivity testing has not been conducted by AGS - but was performed by CTh during their 2007 geotechnical investigation. Based upon the results of their testing and our previous experience in the area it is anticipated that the onsite soil will exhibit "negligible" sulfate concentrations when classified in accordance with ACI 318-05 Table - 4.3.1 (per 2010 CBC) and are anticipated to be "mildly" corrosive to metals. Consultation with a - corrosion engineer is recommended. Final determination of actual chemical/resistivity design parameters for the foundation will be determined at the conclusion of the grading and will be - presented in the grading report. 7.1.7.. Earthwork Adjustments - It is anticipated that the onsite fill/residual soils will shrink on the order of 4 to 6 percent when re- compacted. The paralic deposits are anticipated to bulk on the order of 5 to 10 percent when used to make compacted fill. - 7.1.8. Pavement Support Characteristics It is anticipated that the onsite soils will, have good to moderate support characteristics. Depending upon the final distribution of site soils, pavement support characteristics could vary. If structural pavements are to be constructed (concrete or asphaltic concrete), an "R"-value of 35 - can be utilized for the preliminary design of pavements. Final design should be based upon representative sampling of the as-graded soils. 8.0 CONCLUSIONS AND RECOMMENDATIONS Construction of the proposed residential structure and associated improvements is considered feasible, from a geotechnical standpoint, provided that the conclusions and recommendations presented herein are incorporated into the design and construction of the.project. Presented below are specific issues identified by this study as possibly affecting site development. Recommendations to mitigate these issues are presented in the text of this report. 8.1. Grading Recommendations 8.1.1. Unsuitable Soil Removals In areas to receive settlement sensitive structures, all topsoil/residual soil, highly weathered formational materials, and any undocumented fill soils. It is anticipated that the upper 3 to 4 feet of the onsite: soils will require removal and recompaction for the support of settlement sensitive structures. Localized areas may require deeper removals. Minimally the removals should extend a lateral distance of at least 5 feet beyond the limits of settlement sensitive structures. If deeper removals are performed, the removals should extend a lateral distance equal to the depth of removal beyond the improvement limits. Removal bottoms should expose competent formational materials in a firm and unyielding condition. The resulting removal bottoms should be observed by a representative of AGS to verify that adequate removal of unsuitable materials have been - ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 21, 2012 Page 7 WWI 20 1-02 Report No. 1201 -02-B-2 conducted prior to fill placement In general, soils removed during remedial grading will be suitable for reuse in compacted fills, provided they are properly moisture conditioned and do not contain deleterious materials Grading shall be accomplished under the observation and testing of the project soils engineer and engineering geologist or their authorized representative in accordance with the recommendationscóntained herein, the current'-grading odinance of the City of Carlsbad. 8.1.2. Earthwork Considerations 8.1.2.1. Compaction Standards. Fill and processed natural ground shall be compacted to ,a minimum relative compaction of 90 percent, as determined by ASTM Test Method D 1557. Compaction shall be achieved at or slightly above the optimum moisture content and as generally discussed in the attached Earthwork Specifications (Appendix B). 8.1.2.2. Treatment of Removal Bottoms. At the completion of unsuitable soil removals, the exposed bottom should be scarified to a minimum depth of eight inches, moisture conditioned to above optimum moisture and compacted; in-place to the standards set forth in this report. 8.1.2.3. FilIPlacernènt Fill should be placed in thin lifts (eight-inch bulk), moisture conditioned to at or slightly above the optimum moisture content, uniformly mixed, and compacted by the use of both wheel rolling and kneading type (sheeps foot) compaction equipment until the. designed grades are achieved. 8.13. Cut Fill TransitiOn Lots Where design grades and/or remedial gradmg activities create a cut/fill transition, the cut and shallow fill portions of the building pad shall be overexcavated a minimum depth of three feet or 18 inches below the bottom of the proposed footmgs r (whichever is deeper) and replaced with compacted fill These remedial grading measures are recommended in order to minimize the potential for differential settlements between cut and fill areas The undercut should be graded such that a gradient of at least one percent is.maintàined toward deeper fill areas or the front of the lot. . 8.2. Design Recommendations . . . . . It is our understanding that the proposed foundations will consist of a shallow slab-on-grade foundation systems supporting the proposed two-story wood-frame residential structures It is our further understanding that the foundation system will be conventionally reinforced..with steel reinforcing bars Design recommendations are-provided'.herein In addition to the structure, associated driveways, hardscape and landscape areas are proposed From a geotechnical perspective these proposed improvements a•e feasible provided that the following recommendations areincorporated into the design and construction. 7. ADVANCED GEOIECIINICALSOIIJTIONS, INC. March 2l,2012 Page.8 P1W 1201-02 Report No. 1201-02-B-2 8.2L .Foñndation Design Criteria The single-family residential structure can be supported on conventional shallow foundations and slab-on-grade systems The expansion potential of the underlying soils is classified as "Low" The following yaluesmay be used in the foundation design. Allowable Béanng: 2000 lbs.Isq.ft. Lateral Bearing:. 250 ibs.Isq.ft. ata depth of 12 inches plus 125 lbs./sq.ft; for eachadditidnal 12 inches embedment to a maximum of 2000 lbs.Isq.ft. Sliding Coefficient: 0.35 Settlement: Total = 3/4 inch Differential: 3/8 inch in 20 èet The above values may be increased as allowed by Code to resist transient loads such as wind or seismic. Büilding Code and structural design 'considerations may. govern. Depth and reinforcement requirements should be evaluated by the Structural Engineer. 8.2.2 Seismic Design Parameters The following seismic design parameters are presented to be code compliant to the California Building Code (2010) The subject lots have been identified to be site class "D" in accordance with CBC, 2010, Table 1613.5.3 (1). The lots are located'atLatitudë 33.15682° N and Longitude 117.33252' W Utilizing this information, the computer program USG Earthquake Ground Motion Parameters Version 5.1.0 and ASCE 7 critenon, the seismic design category for 0.20 seconds (S5) and 1 0 second (S1) pen od response accelerations can be determined (CBC, 2010 1613.5.5. 1) along with the design spectral response acceleration (CBC, 2010 1613.5.4). Seismic Design Criteria Mapped Spectral Acceleratioii.(0.2 sec Period),, 5s 1.275g Mapped Spectral AcceleratiOn (1.0 sec Period), S 0A80g. Site Coefficient, Fa 1.0: Site Coefficient, F : 1.52 MCE Spectral Response Acceleration (0.2 secPeriod), SM 1.275g MCE Spectrat Response Acceleration (1.0 sec Period), SM1 0.730g Design Spectral Response Acceleration (0.2 sec Period), SDs 0.850g Design Spectral Response Acceleration (1.0 sec Period), SDI 0.487g ADVANCED GEOTECHNIGAL SOLIJEIONS, INC. March21,2012 Page9 P1W 1201'02 Report No. 1201-02-B-2 8.23. Foundation Dësn ' -' 8.2.3:1. Conventional Foundations Based upon the onsite soil conditions and information supplied by the 2010 CBC, - conventional foundation systems should be 'designed. in accordance With Se&iOn 8.2.1 and .the following recômrnendätions. > Interior and exterior footings for the proposed tw-story residence should be a minimum of 15 inches wide and extend to depth'dfat'least 18 inchesbelow lowest adjacent grade. Footing reinforcement should minimally consist of foUr No. 4 rinforcing bars, two top and two bottom or two No. 5. reinforcing bars, one top and one bottom. " > Conventional, slab-on-grade floors, underlain by "loW' expansive soil, should be five or more inches thick and be reinfOrced with No. 3 or larger reinforcing bars 'spaced 18 inches on center each' way. The' slab reinforcement and expansion joint spacing should be designed by the. Structural' Engineer. > If exterior footings adjacent to drainage swales are to exist within five f exterior eet horizontally of the swale, the footing should be embedded sufficiently to assure embedment below the swale bottom is maintained. 'Footings adjacent to slopes' should be:eñibedded such that a -least- sevenfeet are provided horizontally from edge of the footing to the face Of the slope: > Isolated spread' footings outside the footprint Of the proposed structures should be tied with grade beams to the structure in two orthogonal directiOns. > A grade beajji reinforced continuously, with the garage footings shall 'be constructed across' the garage entrance,, tying' together the ends of the perimeter footings and ' between individual spread footings. This grade beam should be embedded at the same depth as the adjacent '..perimeter footings A thickened slab, separated by a cold Joint from the garage beam, should be provided at the garage entrance Minimum dimensions of-the thickened edge shall bte six (0)i inches deep. Footing depth, 'width and-reinforcement should be:the same as the structure.. Slab thickness, reinforcement and under-slab treatment should be the same as the structure, 8.2.4. UnderSiab ' - Prior to concrete placement the subgrade soils' 'should' be moisture conditioned to optimum 'moisture content ' A moisture and vapor retarding system should be placed below the slabs-on-grade in portions of - the structure considered to be moisture sensitive The retarder should be of suitable composition, thickness, strength and low permeance to effectively prevent the migration of water and reduce the transmission of water vapor to acceptable levels. Historically, a 10-mil 'plastic membrane, - such as Visqueen, placed between one to four in of clean sand, has been used for this - ' purpose. More recently Stego® Wrap or similar underlayments have been used to lower permeance to effectively prevent the migration of water and reduce the transmission of water ADVANCED GEOTECHNICAL. SOUJHONS, INC. March 21,2012 Page40 P1W 1201 -'02 Report No 120 1-02-B-2 vapor to acceptable levels The use of this system or other systems, matenals or techniques can be considered, at the discretion of the designer, pro"ided the system reduces the vapor transmission - rates to acceptable levels 82 5 Deepened Footings and Structural Setbacks It is generally recognized that improvements constructed in proximity to natural.,slopes or properly constructed, manufactured slopes can, over a period of time, be affected by natural - processes including gravity forces, weathering of surficial soils and long-term (secondary) settlement Most building codes, including the California Building Code (CBC), require that - structures be set back or footings deëened, where subject to the influence of these natural - processes For the ub sject site, where foundations for residential structures are to exist m proximity to -. slopes, the footings should be embedded to satisi'thereuiitments preseited in FiguzéT3. - FIGURE 3. - FACE OF FOOTING TOP OF - SLOPE - 4.FACEOF. STRUCTURE H/3 BUT NEED NOTEXCEED 40 Fr. H ToEbF SLOPE 'H)\2BUT NEED NOT EXCEED 15Fr. MAX. 8.2.6. Concrete Design - Our previous-experience in the general area indicates onsite soils likely exhibit a "negligible" sulfate exposure when classified in accordance with ACT 318-05 Table 4.3.1 (per 2010 CBC) Final determination will be based upon testing of near surface soils obtained at the conclusion of - grading However, some fertilizers have been known to leach sulfates into soils otherwise contaimng "negligible" sulfate concentrations ,and increase the sulfate concentrations to potentially detrimental levels It is incumbent upon the owner to detemune whether additional - protective measures are warranted to mitigate the potential for increased sulfate concentrations to - onsite soils as a result of the future homeowner's actions. ADVANCED 6EOCHNICALSOLONS, INC. March 21, 2012 Page 11 P/W 1201-02 Report No. 1201-02-13-2 8.2.7. Corrosion - Our previous experience in the general area indicates onsite soils likely are "mildly" corrosive to buried metallic materials. AGS recommends minimally that the current standard of care be employed for protection of metallic construction materials in contact with onsite soils or that - consultation with an engineer specializing in corrosion to determine specifications for protection of the construction materials. Final determination will be based upon testing of near surface soils obtained at the conclusion of grading. 8.2.8. Retaining Walls The following earth pressures are recommended for the design of retaining walls onsite: Rankine Equivalent Fluid Level Backfill Coefficients Pressure (psf/lin.ft.' - Coefficient of Active Pressure: Ka = 0.31 38 Coefficient of Passive Pressure: K1, = 3.25 407 Coefficient of at Rest Pressure: K0 = 0.47 59 Rankine Equivalent Fluid - 2 : 1 Backfill Coefficients Pressure (psfllin.ft.) Coefficient of Active Pressure: Ka = 0.47 59 Coefficient of Passive Pressure: - Descending K1, (-) = 1.23 154 Coefficient of At Rest Pressure: K. = 0.72 90 The foundations for retaining walls of appurtenant structures structurally separated from the building structure may bear on properly compacted fill. A bearing value of 2,000 psf may be used for design of retaining walls. Retaining wall footings should be designed to resist the lateral forces by passive soil resistance and/or base friction as recommended for foundation lateral resistance. To relieve the potential for hydrostatic pressure wall backfill should consist of a free draining backfill (sand equivalent "SE" >20) and a heel drain should be constructed. The heel drain should be place at the heel of the wall and should consist of a 4-inch diameter perforated pipe (SDR35 or SCHD 40) surrounded by 4 cubic feet of crushed rock (3/4-inch) per lineal foot, wrapped in filter fabric (Mirafi® 140N or equivalent). - Proper drainage devices should be installed along the top of the wall backfill, which should be properly sloped to prevent surface water ponding adjacent to the wall. In addition to the wall drainage system, for building perimeter walls extending below the finished grade, the wall should be waterproofed and/or damp-proofed to effectively seal the wall from moisture infiltration through the wall section to the interior wall face. The wall should be backfilled with granular soils placed in loose lifts no greater than 8-inches - thick, at or near optimum moisture content, and mechanically compacted to a minimum 90 percent relative compaction as determined by ASTM Test Method D1557. Flooding or jetting of - backfill materials generally do not result in the required degree and uniformity of compaction ADVANCED GEO1TCHNICAL SOLUTIONS, INC. Maith21,201.12 Page 12 P1W 1201-02 Report No. 1201-02-B-2 and, therefore, is not recommended The soils engineer or his representative should observe the - retaining wall footings, backdrain installation- and be present during placement of the wall backfill to confirm that the walls are properly backfihled and compacted. 83 Utility Trench Excavation All utility trenches should be shored or laid back in accordance with applicable OSHA standards Excavations in bedrock areas should be made in consideration of underlying geologic structure - AGS should be consulted on these issues during construction 8.4. Utility Trench Backfill - Mainline and lateral utility trench backfill should be compacted to at least 90 percent of maximum dry density as determined by ASTM D 1557 Onsite soils will not be suitable for use as bedding material but will be suitable for use in backfill, provided oversized materials are - removed No surcharge loads should be imposed above excavations This includes spoil piles, lumber, concrete trucks or other construction materials and equipment Drainage above excavations should be directed away from the-banks..Care should be taken to avoid saturation of - the soils. Compaction should be accomplished by mechanical means Jetting of native soils will not be acceptable. 8.5. Exterior Slabs andWalkways -. 8.5:1. Subgrade Compaction The subgrade below exterior slabs, sidewalks, driveways, patios, etc. should be compacted to a - minimum of 90 pement relative compaction as determined by ASTM D 1557. 8.5.2. Subgrade Moisture - The subgradë below exterior slabs, sidewalks,' 'driveways, patios, etc. should be moisture conditioned to a minimum of 110 percent of optimum moisture content prior to concrete placement. 8.5.3. Slab Thickness - Concrete flatwork and driveways should be designed' utilizing four-inch minimum thickness. 8.5.4.. Control Joints - Weakened plane joints should be installed on walkways at intervals of approximately eight to ten feet Extëiior slabs should be designed to withstand shiinkàgeoftheconcrete. - 8.5.5 Flatwork Reinforcement - Consideration should be given to reinforcing any exteriorfiatwork. ADVANCED GEOTECHNICAL SOLIJHONS, INC. Match 21,2012 Page,. 3., P1W 1201-02 Report No 1201-02-B-2 Thickened Edge Consideration should be given to construct a thickened edge (scoop footing) at the perimeter of slabs and walkways adjacent to landscape areas to minimize moisture variation below these improvements The thickened edge (scoop footing) should extend approximately eight.,inches belowconcrete slabs and should be a minimum of six inches wide. 8.6. Plan Review Once grading and foundation design plans become available, they should be reviewed by AGS to verify that the design recommendations presented are consistent with the proposed construction. 8.7. GeOtechnica1Review As is the case in any grading project, multiple working hypotheses are established utilizing the available data, and the most probable model is used for the analysis Information collected during the grading and construction operations is intended to evaluate these hypotheses, and some of the assumptions summarized herein may need to be changed as more information becomes available Some modification of the grading and construction recommendations may become necessary, should the conditions encountered in the field differ significantly than those hypothesized to exist AGS should review the pertinent pians and sections of the project specifications, to evaluate conformance with the intentof the recommendations contained in this report. If the project description or final design vanes from that described in this report, AGS must be consulted regarding the applicability of, and the necessity for, any revisions to the recommendations presented herein AGS accepts no liability for any use of its recommendations if the project description or final design varies and AGS is not consulted regarding the changes. 90 SLOPE AND LOT MAINTENANCE Maintenance of improvements is essential to the long-term performance of structures and slopes. Although the design and construction during mass grading is planned to create slopes that are both grossly and r.surficially stable, certain factors are beyond the control of the soil engineer and geologist The homeowners must implement certain maintenance procedures. The following recommendations should be implemented 9.1. SlOpe Planting Slope planting should consist of ground cover, shrubs and trees that possess deep, dense root structures and require a minimum of imgation The resident should be advised of their responsibility to maintain such planting 92 Lot Drainage Roof, pad andlpt drainage should be collected and directed away from, structures and slopes and toward approved disposal areas Design fine-grade elevations should be maintained through the life of the structure or if dsign fine grade elevations are altered, adequate area drains should be inställèd in order to provide rapid discharge of water, away from structures and slopes. Residents ADVANCED GEOTECHNICAL. SOLUTIONS' INC March 21, 2012 Page 14 P/W 1201-02 Report No. 1201-02-B-2 should be made aware that they are responsible for maintenance and cleaning of all drainage terraces, down drains and other devices that have been installed to promote structure and slope stability. - 93. Slope Irrigation The resident, homeowner and Homeowner Association should be advised of their responsibility to maintain irrigation systems. Leaks should be repaired immediately. Sprinklers should be - adjusted to provide maximum uniform coverage with a minimum of water usage and overlap. Overwatering with consequent wasteful run-off and ground saturation should be avoided, if automatic sprinkler systems are installed, their use must be adjusted to account for natural rainfall - conditions. 9.4. Burrowing Animals Residents or homeowners should undertake a program for the elimination of burrowing animals. This should be an ongoing program in order to maintain slope stability. 10.0 LIMITATIONS This report is based on the project as described and the information obtained from the referenced geotechnical investigation report and the excavations at the approximate locations indicated on the Figure 2. The findings are based on the results of the field, laboratory, and office investigations combined with an interpolation and extrapolation of conditions between and beyond the excavation locations. The results reflect an interpretation of the direct evidence obtained. Services performed by AGS have been conducted in a manner consistent with that level of care and skill ordinarily exercised by members of the profession currently practicing in the same locality under similar conditions. No other representation, either expressed or implied, and no warranty or guarantee is included or intended. The recommendations presented in this report are based on the assumption that an appropriate level of - field review will be provided by geotechnical engineers and engineering geologists who are familiar with the design and site geologic conditions. That field review shall be sufficient to confirm that geotechnical and geologic conditions exposed during grading are consistent with the geologic representations and corresponding recommendations presented in this report. AGS should be notified of any pertinent changes in the project plans or if subsurface conditions are found to vary from those described herein. Such changes or variations may require a it-evaluation of the recommendations contained in this report. The data, opinions, and recommendations of this report are applicable to the specific design of this project - as discussed in this report. They have no applicability to any other project or to any other location, and - any and all subsequent users accept any and all liability resulting from any use or reuse of the data, opinions, and recommendations without the prior written consent of AGS. AGS has no responsibility for construction means, methods, techniques, sequences, or procedures, or for - safety precautions or programs in connection with the construction, for the acts or omissions of the CONTRACTOR, or any other person performing any of the construction, or for the failure of any of them to carry out the construction in accordance with the final design drawings and specifications. - ADVANCED GEOTECHNICAL SOLtJIIONS, INC. March 21, 2012 Page 15 P1W 1201-02 Report No. 1201-02-13-2 REFERENCES - American Concrete Institute, 2002, Building Code Requirements for Structural Concrete (ACI318M-02) and Commentary (ACI3J8RM-02), ACI International, Farmington Hills, Michigan. - American Society for Testing and Materials (2008), Annual Book ofASTM Standards, Section 4, Construction, Volume 04.08, Soil and Rock (1), ASTM International, West Conshohocken, Pennsylvania. California Code of Regulation, Title 24,2010 California Building Code, 3 Volumes. - Construction Testing and Engineers, Inc., Preliminary Geotechnical Investigation, Proposed Three Lot Residential Development, 1369 Magnolia Avenue, Carlsbad, California, dated April 3, 2007 (CTE Job No. 10-8791 G). Kennedy, M.P., Tan, S.S., et. al., 2007, Geologic Map of the Oceanside 30' x 60' Quadrangle, California, California Geological Survey: Regional Geologic Map.No. 2, scale 1:100,000. ADVANCED GEOTECHNICAL. SOEIJHONS, INC. 4 SGUTY I rx,cr RinG I 205-280-17 NEW 6' SCUD WOOD FM CE N.A.P. - -S - - -. -.--- - LaJ flL. A I • FF= 757. PAD= 156 -•2ao'— GROSS ARtA=9 896 SF ,Er4f=9496 sv - Qg N.AIP. -HA-1 PALM UN Iii. PR0ECTL,a71 ] I I TI Q2P IRMA 0528038 TBTh L EXIST. BLDG - - EAR 1BA - - - GROSS ARE4= NET ARE4-11 14 551 395 SF o I :1 Qop I j 17-7 rJLrLUNf 1 Kk4ki'TP-6 —6' swD 81 - . 205-280-67 2-0& "DGSIING 5' SCUD NCO Fl 10 RDA4IN PIlOT ru7_s E4 5 1 L' V1 EXISI7NGPERCDP 10<18".;* ._l&2Qf&a2i1Tp3 GROSS ARE4 NET ARM- Approximate Location of Exploratory Excavation,. .HA-2 AGS, 2012 Approximate Location of Exploratory-Trench, . FIGGRAPHIC SCAU URE.2 TP6 CTE' 20' ¶0' .. 20' so' GeologicMap and ,1 Exploration Location Plan Old -Paralic Deposits (formerly mapped, as Terrace WOp. .... ;4,, . ADVANCED GEOTECHNOCAL-SOLUTIONS, INC Deposits) 5333 Mission Center Road, Suite 390 Son Diego, California 92108 N.A.P. Not a Part of Report . . . "r#/ Telephone: (619) 708-1649 Fax: (714)409-3287 APPENDIX A FIELD AND LABORATORY DATA ADVANCED GEOTECHNICAL SOLUTIONS, INC., 2012 CONSTRUCTION TESTING AND ENGINEERING, INC., 2007 ADVANCED (iEOTECHNICAL SOUJTIONS, INC. ADVANCED GEOTECHNICAL SOLUTIONS, INC. LOG OF EXPLORATORY EXCAVATION P1W NO.: 1201-02 LOGGED BY: PJD - PROJECT NAME: 1369 Magnolia EQUIPMENT: Hand Excavated CLIENT: New Pointe Comiujnities DATE: 3/16/2012 LOCATION: See Bdoration Location Plan — SAMPLES Laboratory Testing — Hand Auger HA-1 E °- In E 0 — w co MATERIAL DESCRIPTION AND COMMENTS - Topsoil/Residual Soil (Undifferentiated) • SC Light gray brown to brown, moist, loose, CLAYEY SAND with silt, fine- - HAl-i to medium grained El= 34 SM Light brown to red brown, moist, loose to medium dense, SILTY SAND,fine- tomediumgrained;traceclay - - OldParalicDeposits - \... SM Light gray brown to orangish brown, slightly moist, dense, SILTY SAND Excavation Terminated at 3.5 Feet - No Groundwater Encountered Backfilled with Soil Cuttings 10 - 15 - fSamote Type: Small Plastic Bag — Bulk Sample —Water. Table LU O Laboratory Testing: AL = Attetheig Limits El = Expansion Index MD = Maximum Density SA = Sieve Analysis LU ..J SR = Sulfate/Resistivity Test SH = Shear Testing RV = R-Value Test CO = Consolidation ADVANCED GEOTECHNICAL SOLUTIONS, INC. LOG OF EXPLORATORY EXCAVATION P1W NO.: 1201-02 LOGGED BY: PJD PROJECT NAME: 1369 Magnolia EQUIPMENT: Hand Excavated CLIENT: New Pointe Conminities DATE: 3/16/2012 LOCATION: See Exloration Location Plan - SAMPLES Laboratory Testing - - 'b CL :3 E W Hand Auger HA-2 CL C.) 0 q .--- 0 CL , - Q. E Cl) a - 0 MATERIAL DESCRIPTION AND COMMENTS - " Topsoil/Residual Soil (Undifferentiated) SM Light gray brown to light brown, slightly moist, loose to medium dense, SILTY SAND, fine- to medium-grained; trace clay OldParalicDeposits SM Light gray brown to orangish brown, slightly moist, dense. SILTY SAND; weakly cemented Excavation Terminated at 3.5 Feet No Groundwater Encountered Backfilled with Soil Cuttings 10 15 93 1Sample 11~71 Type: Small Plastic Bag Lnsj _ Bulk Sample —Water Table O Laboratory Testing: AL =Atterberg Limits El = Expansion Index MD Maximum Density SA = Sieve Analysis Lu SR = Sulfate/Resistivity Test SH = Shear Testing RV R-Value Test CO = Consolidation :1111 111IN c —\ CONSTRUCTION. TESTING & ENGINEERItIG, INC. O(ofDcAnlgu CCND'DUCD:OM EsD'uAINu VDZHNO AND INDP&1 ni .0 •JDAIIII ROAD, SAul lii $ JUO*JiO, Cu $0111 I PlO PROJECT: Three Lot Development EXCAVA'JX')R: D. Higgenbotharn c-rr JOB NO: lO-8791c3 EXCAVATtONMThOl): BACKHOE EXCAVATION b.'\'II: 2/I(/,'(II.17 LOUUDBY: 1)1< SAMPLft'CJMETtIOD: BULK ELEVATION: - TEST PIT LOG TP-1 luutIcol ii DESCRIPTION 0-I TOPSOIl..: Loose to rnediuii dense. slightly tmukl. dark browi', silty SAND (SM) with i'tuu'iloiganics, 'REM \\•\ RV. ( ,&• .J 1-3 R2SIDUAL SOIL - - . Medium dense, slightly moist. light biown - -Qf to tun, silty One SAND (SM) . \ 3-6 OUATE RNARY TERRACE DPOSITSj. i.)ense. slightly moist, light brown - to ton. , fine SAND SM fota; (tc11111 6 fig No ground wt icr lRackfilled with spoils S -10- ". . F i p. -15- 10 40 a. ...• _________ o c2 CONSTRUCTION TESTING &ENGINEERING,INC. - Dr T(CIn I II CONSTRUC110M ONOIN110UIn III lIMO Afl In i•i C 11DM 'I. I ltOfl(I t$.O. 3ar1 II I I5rOII 0100. CI 01*00 710 .I.,Ij PROJECT: 11irec Lot Development EXCAVATOR: D. iliggenhot ham CIE JOB JO: 1087910 EXCAVATION METHOD: tACKHQE Fxc.\vATtoN D.Vt'( LOGC,Eb 131: DK - SAMPLINQMETIIOD: BULK tt.1ATlON:__- - : 4 . TEST PIT LOG: TP-2 Cl 3 Zi : C DESCRIPTION - • . / 'Loose to niedkrm dense, dry to slightly moist. \-/ twowii. silty Fine grained SANt) (SM) with dehii - \ . . J and organic materials (foUrs. lop j. - / 1.5-3' RESIDUAL 501 - - Qi Medium dense. slightly moist. light brown to Lan. silty tineSAND(SM). - - 5. 5' OUA1ERNAY TERRACE DEPpSfl.jQu - Total depth 5.5' ftp Dense, slightly moist. mottled orange brown - No tioundsvatr to tan, silty fine SAND (SM). - 13ack1i11ed with spoiI -1€ -Is - - - - - - J9CitJRE:L (P2 CONSTRUCTION TESTING & ENGINEERING, INC. G (I CCHNICI P C111431PUCTION EN:,lll I Ifl II ITl4O I,.IlCTIVI, IDI MODPI1 U In. $IPI& P I SCOITPUO. CI P7311 I Ill IsPp. - PROJECT: Three Lot Dcvcloprnenr E>W.VAOfl: D. Higgeitborham CTEJOR NO: 10879}G EXCAVATION METHOD: BAcicr-toE F.\c:Av..TicJ DATE. .'l(p/2(I" LC)CC1C) 0i: D}C SA1VLING METHOD: BULX ELEVATION"-• 1 .. TEST PIT LOG: TP-3C. uutiv li O i:;• - L C. DESCRTPTrON ,. • — - — - —a ---- -- -_____ ,,_ 4 0•l....OPSO1I.: Loose (ii medium dense. tihtl moist. / dark brown, silty SAND (SM) with rooisfoiaiiic 7 l.S.Y RESID UALSO • \ / tvledium dense, slightly moist. light brown to tan.- silty fine SAND (SM). - . \Qt . 35 5- Dense, slightly moist. mottled orange L'itiwn Total depth to tan. silty fine SAND (SM). No groundwater • Bucktilled with polls S . . '5 . .• ( Flur(i 1 11 3 CONSTRUCTION TESTING & ENGINEERING, INC. 8TECIINICA I COISO I tll.1 50 C 50101 01050 1(11,00 - 0500 I I1U CII 05 .IiqIili 00110. II.., I II I 510PICIOC. C I 5159 III !SI 05' PROJECT: Three Lor Development . . EXCAVATOR: D. Higgenbotham c-iios NO; 10-87913 IiXCAVATION METHOD: IIACKHOP EXCAVATION D.IL: 2/I6/CU LOGGED DY: DK - - - SAMPLIN(IMETHOD: BULK ELEVATIO': C .. ." TEST PIT LOG: TP-4 A Tci1!. .. : 0 I)ESCRIF1ION - - -o- - - ,L. ) 0-75 TOPSOfl Loose to niedkirndee. s I i ghtl y mj dark brown silty SAND (SM:) with mots/cligallic \ / materials. - . . / 75 3 RESIDUAL SOiL. - / Medium dense to dense, slightly muiL light biown - - - . / and clirk brown, silty SAND (SPA). - / 3.61 QUATERNARY TERRACE DtPOSITS COt): Dense to very dense, slightly moist. light brown ''-_---- - - and dark brown, silty SAND (SM-).with small' - - :—.25') weathered quartz nodules, Total depth 6 thg No groundwater - Backfi lIed with cuttings -IE - --/ ( GURE:j /\. I- CONSTRUCTION TESTING & ENGINEERING, INC. - MCIt £fl. Iwo I IC I £ $OKIICfl. Ct 11111 I 710.11 I III! t £ U CH?IA COI. ?AU II Q ENflhPU4IIIC It iISN@ £O I ty, C IO PRO1t3C17: Three Lot Development EXCAVATOR: D. Higenbotham C1E JOB NO: 10-879J G CAVA'i ION 1\IEF&ioo: BACK}1013 EXCAVATION t.)AIT: 2/16/21107 LOGGED BY: DK SI'U\1PLINc1 METHOD: BULK ELEVATION; 156 - — . . ' if ' TEST PIT LOG: TP-5 - l)l7raLoIy1et..; U . i S C a m 0 DESCRIPTION ToPsu -- — Medium dense, slightly moist, mottled light brown - --- / f to brown, silty fine SAND (SW[) with roots / and orIlic nioteriul. - / RJELSIDU - Qt .S Medium dense to dense. slightly moist. light brown ," and dark- brown. silty SAA Total depth 11.5 lhg • Loose. di • ptie gray. fine. to coarse sand tSP.SWI. - No gJoUnd\Yar l3ackfiticd vvitli spoils 3-I OUAflR'ARYTERRAE DEP()S1TStOIm: — Dense to very dcuse. sl iglitly moist. light brown — and clurk brown. silly Si\Nt) (SM) with small -.25) veathercd quartz mmodule, I Jr ii ... . flGURE:L •fl) 10.6 wow 04 #60 OW94061016v t) w w. w ww - — - CONSTRUCTION TESTING & ENGINEERING. INC. QfOIa.,,IICAt I CO,PIHUCIID EIIW1EIIIiu THT1114 INC IPIS,CC,IAC (N ___ a a WCI fl iou. S11 Iii (UUCPIIC. Ca 101,0 I 7I 111.1 III PROJECT: Three Lot Development -- EXCAVATOR: D. Higgenbotham -- Ci.JO[4 No: I0-8791G EXCAVATION METHOD: BA('KHOB EXC.V.\IlON D;VrE. WOOED J3v: DK SAMPLINGMFT}OD: RULK ELEVATION:____ 26 c ! 0 TEST PIT LOG: TP-6 uT 73 D1SCRIPT[ON 0-I' LQ \ f too brown. silty (inc SAN]) (SM) with rou::.ond initciiaIs. - / 1-3 REM DUAL SOtL: Q' Medium dense to dense, slightly moist. hrovri to - — light brown. silty fine SAND (SM). 3' OUiVIERNARY ThRRAC DEPOSLTSjOr Dense, slightly moist, brown to - - Total depth 5' bg light brown, silty line. SAND (SM). - . No groundwater Baekfilled with spoils - _-/ Medium dense. slightly moist. norId light hr"vn 18 . IS- CONSTRUCTION TESTING & ENGINEERING, INC. :...t Er' • • 3t tU:'. t. •tflIt',. 2(R) WASU ANALYSIS 1.01 7t1V)N H., PLR(ENT I'AsSH\(; (I.:NIF!C..lI(,1c i feet O() SIFE i•p.I 1-3 ZO.3 TI'-4 4-li 24.1 SM 6.3 SI'-MI RESISTANCE "R"-VALUE CALTEST 3W LOCA11O.J DEPTH R-VALUE ( TPI - i 74 SULFATE LOCATION DEPTH RESULTS (feet) - Will TV-I I-S 45.9 CHLORIDE LOCATION DEPTH RTSULTS (fcetj ppm TV-I 1-3 CONDUCTIVITY CALIEflRC"1A TEST 1124 LOCViION DIPTh RESULTS Iiiet) - nS/cm TV-I I-S Mll RESISTIVITY CALIFORNIA TEST 424 LOCATION DEPTH RESUI-TS (fix () )hnilc,u TV-I 1-3 11)401) - rYI.XMUM DRY DENSITY & OPTIMUM MOISTURE CONTENT (MODIFIED PROC3OR) LOCATION 0131H OPT1MU1LMO1STURE DRY DEJSITY ifeet) () slicfl IP-3 . :s-i - 9.5 124:5 LA01)R:VII)R'V SI '-MARY (!1 .)flfl NO. I-'7"j Ii C L)nr --- - --- -I-- - -- I . 0 II) 15 20 25 30 35 PERCENT MOISTURE (%) llli~a ASTM D1557 METHOD IX] A 0 B 0 C 10 MODIFIED PROCTOR RESIJLTS LAB NUMBER %AP*IPLr NUMBER TH (FJT; SOIL DESCRIPTION MAXIMUM DRY DENSITY (pcF) CONTENT 17078 - TP-3 0.5-I BROWN SILTY SAND 124.5 9.5 CTE JOB NO: CONSTRUCTION TESTING & ENGINEERING, INC. DATE: 03/07 .J GAtEC"HCL 10 1TWAMD ESD1 IS EbCOI.0CIt78,7li3,M6.45 FIGURE: U-I 10-8791G 9____9 - APPENDIX B GENERAL EARTHWORK SPEC WICATIONS AND GRADING GUIDELINES ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 21,2012 1. P1w 1201-02 Page B-I Report No. 1201-02-B-2 GENERAL EARTHWORK SPECIFICATIONS I. General A General procedures and requirements for earthwork and grading are presented herein.'The earthwork and gading recommendations provided in the geotechnical report are considered part of these specifications, and where the general specifications provided herein conflict with those provided in the geotechnical report, the recommendations in the geotechnical report shall govern Recommendations provided herein and in the geotechnical report may need to be modified depending on the conditions encountered during grading. B The contractor is responsible for the satisfactory completion of all earthwork in accordance with the project plans, specifications, applicable building codes, and local governing agency requirements Where theSe requirements cOnflict, the stricter requirententS shall govern. - C. It is the contractor's responsibility to read and understand the guidelines presented herein and in the geotedimcal report as well as the project plans and specifications Information presented in the geotechnidal report is subject to verification during grading The information presented on the exploration - logs depicts conditions at the particular time of excavation and at the location of the excavation Subsurface conditions present at other locations may differ, and the passage of time may result in different subsurface conditions being encountered at the locations of the exploratory excavations The contractor shall perform an independent investigation and evaluate the nature of the surface and subsurface conditions to be encountered and the procedures and equipment tobe used in performing his work.- The contractor shall have the responsibility to provide adequate equipment and procedures to accomplish the earthwork in accordance with applicable requirements When the quality of work is less than that irequired, the Geotechnical Consultant may reject the work and may recommend that the operations be suspended until the conditions are corrected. Prior to the start of- grading, a qualified Geotechnical Consultant should be, employed to observe grading procedures and provide testing of the fills for conformance with the project specifications, approved grading plan, and guidelines presented herein:.All remedial removals, clean-outs, removal bottoms, keyways, and subdrain installations should be observed and documented by the Geotechnical Consultant prior to placing fill It is the contractor's responsibility to apprise the Geotechnical. Consultant of their schedules and notify the Geotechnical Consultant when those areas are ready for observation. F.,.-The contractor is responsible for providing a safe environment for the Geotechnical Consultant to observe grading and conduct tests. H. Site Preparation A. Cleaing and Grubbing: Excessive vegetation and other deleterious material shall be sufficiently removed as required by the Geotechnical Consultant, and such materials shall be properly disposed of offsite in a method acceptable to the owner and governing agencies Where applicable, the contractor may obtaih permission from thèGeotechnical Consultant, owner, and governing agencies to dispose of vegetation and otherdeleterious materials in designated areas onsite. ADVANCED GEOTECHNICAL. SOUJflONS; INC. March 21, 2012 Page B-2 P1W 1201-02 Report No. 1201-02-13-2 Unsuitable Soils Removals: Earth materials that are deemed unsuitable for the support of fill shall be removed as necessary to the satisfaction of the Geotechnical Consultant. Any underground structures such as cesspools, cisterns, mining shafts, tunnels, septic tanks, wells, pipelines, other utilities, or other structures located within the limits of grading shall be removed and/or - abandoned in accordance with the requirements of the governing agency and to the satisfaction of the Geotechnical Consultant. - D. Preparation of Areas to Receive Fill: After removals are completed, the exposed surfaces shall be scarified to.a depth of approximately 8 inches, watered or dried, as needed, to achieve a generally uniform moisture content that is at or near optimum moisture content. The scarified materials shall, then be - compacted to the project requirements and tested as specified. All areas receiving fill shall be observed and approved by the Geotechnical Consultant prior to the placement of fill. A licensed surveyor shall provide survey control for determining elevations of - processed areas and keyways. HI. Placement of Fill Suitability of fill materials: Any materials, derived onsite or imported, may be utilized as fill provided that the materials have been determined to be suitable by the Geotechnical Consultant. Such materials shall be essentially free of organic matter and other deleterious materials, and be of a gradation, expansion - potential, and/or strength that is acceptable to the Geotechnical Consultant. Fill materials shall be tested in a laboratory approved by the Geotechnical Consultant, and import materials shall be tested and approved - prior to being imported. Generally, different fill materials shall be thoroughly mixed to provide a relatively uniform blend of materials and prevent abrupt changes in material type. Fill materials derived from benching should be - dispersed throughout the fill area instead of placing the materials within only an equipment-width from the cut/fill contact. - C. Oversize Materials: Rocks greater than 8 inches in largest dimension shall be disposed of offsite or be placed in accordance with the recommendations by the Geotechnical Consultant in the areas that are designated as suitable for oversize rock placement Rocks that are smaller than 8 inches in largest - dimension may be utilized in the fill provided that they are not nested and are their quantity and distribution are acceptable to the Geotechnical Consultant The fill materials shall be placed in thin, horizontal layers' such that, when compacted, shall not exceed - 6 inches. Each layer shall be spread evenly and shall be thoroughly mixed to obtain near uniform moisture content and uniform blend of materials. - E. Moisture Content: Fill materials shall be placed at or above the optimum moisture content or as recommended by the geotechnical report. Where the moisture content of the engineered fill is less than recommended, water shall be added, and the fill materials shall be blended so that near uniform moisture content is achieved. If the moisture content is above ,the limits specified by the Geotechnical Consultant, the fill materials shall be aerated by discing, blading, or other methods until the moisture content is acceptable. - ADVANCED GEOTECHNICAL. SOLUTIONS, INC. Maich21,2012 Page B-3 PiW 1201-02 ' Report No. 1201-02-B-2 F.'Eàch.layer of flllsha!l be compacted to the project standards in accordance to the projectspecifications and recommendations of the Geotechnical Consultant Unless otherwise specified by the Geotechnical - Consultant, the fill shall be compacted to a minimum of 90 percent of the maximum dry density as determined by ASTM. Test Method: D1557-09. - G Benching Where placing fill on a slope exceeding a ratio of 5 to I (horizontal to vertical), the ground should be keyed or, benched The keyways and benches shall el. xtend through all unsuitable materials into suitable materials such as firm materials or sound bedrock or as recommended by the Geotechnical - Consultant The minimum.,keyway width shall be 15 feet and extend into suitable materials, or as recommended by the geotechnical report and approved by the Geotechnical Consultant The minimum keyway width for fill over cut slopes is also 15 feet, or as recommended by the geotechnical report and - approved by the Geotechnical Consultant As a general fule, unless otherwise recommended by the Geotechnical Consultant, the minimum width of the keyway shall be equal to 1/2 the height of the fill slope: ' H Slope Tam The specified minimum relative compaction shall be maintained out to the finish face of fill and stabilization fill slopes Generally, this may be achieved by overbuilding the slope and cutting - back to the compacted core The actual amount of overbuilding may vary as field conditions dictate Alternately, this may be achieved by back rolling the slope face with suitable equipment or other methods that produce the designated result. Loose soil should not be allowed to build up on the slope face If - ' present,' lo 'shall, be trimmed to expose tile compated slope face. I Slope Ratio Unless otherwise approved by the Geotechnical Consultant and governing agencies, - permanent fill slopes shall be designed and constructed no steeper than 2 to 1 (horizontal to vertical) Natural Ground and Cut Areas; Design grades that,are in natural ground or in cuts should, be evaluated by the Geotechnical Consultant to determine whether scarification and processing of the ground and/or - 'overexcavation is needed. Fill materials shalt not be placed, spread, or, compacted during unfavorable weather conditions. When - grading is interrupted :by rain, filing operations shall not resume until the Geotechnical Consultant approves the moisture and density of the previously plated compacted fill. 1V. Cut Slopes The Geotechnical Consultant shall inspect all cut slopes, including fill over cut slopes,.and shall be notified by the contractor when cut slopes are started. If adverse or potentially adverse conditions are encountered during grading; the Geotechnical Consultant shall investigate, evaluate, and make recommendations to mitigate the adverse conditions. Unless otherwise stated in the geotechnical report, cut slopes shall not be excavated higher or steeper than the requirements, of the local governing agencies. Short-term stability of the cut slopes' and other excavations is the contractor's responsibility. V., Drainage A. Back 'drains and Subdrains: Back drains and subdráins shall be'provided in fill as recommended by the Geotechnical Consultant and shall, be 'constructed in accordance with the governing agency and/or ADVANCED GEOTECHNOCAL SOLUJITIONS, INC. Page B4 Report No. i-201-01- recommendations of the Geotechnical Consultant The location of subdrains, especially outlets, shall be surveyed and recorded by the Civil Engineer. B Top-of-slope Drainage Positive drainage shall be established away from the top of slope Site ärainage shall,not be permitted to flow over' the tops of slopes. . C Drainage terraces shall be constructed in compliance with the governing agency requirements and/or in accordance withthe recommendations of the Geotechnical. Consultant. D Non-erodible interceptor swales shall be j1aced at the top of cut slopes that face the same direction as the prevailing drainage. VI. Erosion Control Màith 21,201.2 P/W1201-02 A Ail 'finish cut and fill slopes shall be protected from erosion and/or planted in acconlance with the project specifications and/or landscape architect's recommendations Such measures to protect the slope face shall be undertaken as soon as practical after completioi of grading B During construction, the contractor shall maintain proper drainage and prevent the ponding 'of water. The contractor shall take remedial measures to prevent the erosion of graded areas until permanent drainage and erosion control measufes have been installed. VII. Trench Exëavation and Backfill A Safety The contractor shall follow all OSHA requirements for safety of trench excavations Knowing And. following these requirements is the contractor's responsibility. All trench excavations or open cuts in excess of 5 feet in depth shall be shored or laid back Trench excavations and open cuts exposing adverse geologic conditions may require further evaluation by the Geoechmcal Consultant. If a contractor fails to provide safe access fOr compaction testing, backfill nottested due to safety concerns may be subject to removal. B Bedding Bedding materials shall be non-expansive and have a Sand Equivalent greater than 30 Where permitted by the Geotechnical Consultant, the bedding materials can be densified by jetting C Backfill Jetting of backfill materials is generally not acceptable Where permitted by the Geotechnical Consultant, the bedding materials can be densified by jetting provided the backfill materials are granular, free-draining and have a Sand Equivalent grater than 30. Tffl Geotechmcal Observation and Testing Dunng Grading A Compaction Testing:' esting Fill shall be tested by the Geotechnical Consultant for evaluation of general compliance with the recommended compaction and moisture conditions The tests shall be taken in the compacted soils beneath the surface if the surficial materials are disturbed. The contractor shall assist the Geotechnical Consultant by excavating suitable test pits for testing of compacted fill B Where tests indicate that the density of a layer of fill is less than required, or the moisture content not within specifications, the Geotechnical Consultant shall notify the contractor of the unsatisfactory conditions of the filL The portions of the fill that ar iot within specifications shall be reworked until the required density and/or moisture content has been attained No additional fill shall be placed until the last lift of fill is tested and found to meet the project specifications and approved by the Geotechnical Consultant.: . ADVANCED GEOTECIINICALSOLIJUONS, INC. March 21,2012 Page B-5 P/W 1201-02 Report No. 1201-02-13-2 If, in the opinion of the Geotechnical Consultant, unsatisfactory conditions, such as adverse weather, excessive rock or deleterious materials being placed in the fill, insufficient equipment, excessive rate of fill placement, results in a quality of work that is unacceptable, the consultant shall notify the contractor, and the contractor shall rectify the conditions, and if necessary, stop work until conditions are satisfactory. Frequency of Compaction Testing: The location and frequency of tests shall be at the Geotechnical Consultant's discretion. Generally, compaction tests shall be taken at intervals not exceeding two feet in fill height and 1,000 cubic yards of fill materials placed. Compaction Test Locations: The Geotechnical Consultant shall document the approximate elevation and horizontal coordinates of the compaction test locations. The contractor shall coordinate with the surveyor to assure that sufficient grade stakes are established so that the Geotechnical Consultant can determine the test locations. Alternately, the test locations can be surveyed and the results provided to the Geotechnical Consultant. Areas of fill that have not been observed, or tested by the Geotechnical Consultant may have to be removed and recompacted at the contractor's expense. The depth and extent of removals will be - determined by the Geotechnical Consultant. Observation and testing by the Geotechnical Consultant shall be conducted during grading in order for - the Geotechnical Consultant to state that, in his opinion, grading has been completed in accordance with the approved geotechriical report and project specifications. Reporting of Test Results: After completion of grading operations, the Geotechnical Consultant shall submit reports documenting their observations during construction and test results. These reports may be subject to review by the local governing agencies. ADVANCED GEOTECIUNICAL SOUJEIONS, INC. APPENDIX C HOMEOWNER MAINTENANCE RECOMMENDATIONS ADVANCED GEOTECHNICAL SOLUTIONS, INC. HOMEOWNER MAINTENANCE AND IMPROVEMENT CONSIDERATIONS Homeowners ale accustomed to maintaining their homes. Thçy expect to paint their houses periodically, replace wiring, clean out clogged plumbing, and repair roofs Maintenance of the home site, particularly on hillsides should be considered on the same basis or even on a more serious .basis because neglect can result in serious consequences In most cases, lot and site maintenance can be taken care of along with landscaping and can be carried out more economically than repair after neglect Most slope and hillside lot problems are associated with water Uncontrolled water from a broken pipe, cesspool, or wet weather causes most damage Wet weather is the largest cause of slope problems, particularly in California where rain is intermittent, but may be torrential Therefore, drainage and erosion control are the most important aspects of home site stability, these provisions must not be altered without competent professional advice Further, maintenance must be carned out to assure their continued operation. As geotechnical engineers concerned with the problems of building sites in hillside developments, we offer the following list of recommended home proteôtion measures as a guide to homeowners. Expansive Soils Some of the earth materials on site have been identified as being expansive in nature. As such, these materials are susceptible to volume changes with variations in their moisture content These soils will -- swell. upon the introduction of water and shrink, upon drying. The forces associated with these volume changes can have significant negative impacts (in the form of differential movement) on foundations, walkways, patios, and other lot improvements In recognition of this, the project developer has constructed homes on these lots on post-tensioned or mat slabs with pier and grade beam foundation systems intended to help reduce the potential adverse effects of these expansive materials on the residential structures within the project Such foundation systems are not intended to offset the forces - (and associated movement) related to expansive soil, but are intended to help soften their effects on the structures constructed thereon. Homeowners purchasing property and living in an area containing expansive soils must assume a certain degree of responsibility for homeowner improvements as well as for maintaining conditions around their home Provisions should be incorporated into the design and construction of homeowner improvements - to account for the expansive nature of the onsite soils material. Lot maintenance and landscaping should also be conducted in consideration of the expansive soil characteristics Of primary importance is minimizing the moisture variation below all lot improvements Such design, construction and homeowner maintenance provisions should include: • Employing contractors for homeowner improvements who design and build in recognition of - local building code and site specific soils conditions Establishing and maintaining positive drainage away from all foundations, walkways driveways, patios, and Other hardscape improvements. :Avoiding the construction of planters adjacent to structural improvements. Alternatively, planter - 'sideslbdttoms can, bè:sealed 'with an impermeable membrane and drained away from the improvements Via sübdrains into approved disposal areas. , 'Sealing and maintaining construction/control joints within concrete slabs and walkways to reduce - the potential for' moisture infiltration into the subgrade soils. - • ADVANCED GEOTECIINICAL SOLUTIONS, INC. Utilizing landscaping schemes with vegetation that-requires minimal, watering. Alternatively, watering should be done in a uniform manner as equally as possible on all sides of the foundation, keeping the soil "moist" but not allowing the soil to become saturated. - •• Maintaining positive drainage away from structures and providing roof gutters on all structures with downspouts installed to carry roof runoff directly into area drains or discharged well away from the structures. - • Avoiding the placement of trees closer to the proposed structures than a distance of one-half the mature height of the tree. •• Observation of the soil conditions around the perimeter of the structure during extremely hot/dry or unusually wet weather conditions so that modifications can be made in irrigation programs to maintain relatively constant moisture conditions. Sulfates Homeowners should be cautioned against the import and use of certain fertilizers, soil amendments, and/or other soils from offsite sources in the absence of specific information relating to their chemical composition. Some fertilizers have been known to leach sulfate compounds into soils otherwise containing "negligible" sulfate concentrations and increase the sulfate concentrations in near-surface soils to "moderate" or "severe" levels. In some cases, concrete improvements constructed in soils containing high levels of soluble sulfates may be affected by deterioration and loss of strength. Water - Natural and Man Induced Water in concert with the reaction of various natural and man-made elements, can cause detrimental effects to your structure and surrounding property. Rain water and flowing water erodes and saturates the ground and changes the engineering characteristics of the underlying earth materials upon saturation. -, Excessive irrigation in concert with a rainy period is commonly associated with shallow slope failures and deep seated landslides, saturation of near structure soils, local ponding of water, and transportation of water soluble substances that are deleterious to building materials including concrete, steel, wood, and - stucco. Water interacting with the near surface and subsurface soils can initiate several other potentially detrimental phenomena other then slope stability issues. These may include expansion/contraction cycles, liquefaction potential increase, hydro-collapse of soils, ground surface settlement, earth material consolidation, and introduction of deleterious substances. - The homeowners should be made aware of the potential problems which may develop when drainage is altered through construction of retaining walls, swimming pools, paved walkways and patios. Ponded water, drainage over the slope face, leaking irrigation systems, over-watering or other conditions which - could lead to ground saturation must be avoided. Before the rainy season arrives, check and clear roof drains, gutters and down spouts of all - accumulated debris. Roof gutters are an important element in your arsenal against rain damage. If you do not have roof gutters and down spouts, you may elect to install them. Roofs, with their, wide, flat area can shed tremendous quantities of water. Without gutters or other adequate drainage, water falling from the eaves collects against foundation and basement walls. - •• Make sure to clear surface and terrace drainage ditches, and check them frequently during the rainy season. This task is a community responsibility. •• Test all drainage ditches for functioning outlet drains. This should be tested with a hose and done before the rainy season. All blockages should be removed. ADVANCED GEOIECHNUCAL. SOUJEIONS, INC. - •• Check all drains at top of slopes to be sure they are clear and that water will not overflow the slope itself, causing erosion. ) Keep subsurface drain openings (weep-holes) clear of debris and other material which could - block them in a storm. •• Check for loose fill above and below your property if you live on a slope or terrace. •• Monitor hoses and sprinklers. During the rainy season, little, if any, irrigation is required. Oversaturation of the ground is unnecessary, increases watering costs, and can cause subsurface drainage. + Watch for water backup of drains inside the house and toilets during the rainy season, as this may indicate drain or sewer blockage. •• Never block terrace drains and brow ditches on slopes or at the tops of cut or fill slopes. These are designed to carry away runoff to a place where it can be safely distributed. •• Maintain the ground surface upslope of lined ditches to ensure that surface water is collected in the ditch and is not permitted to be trapped behind or under the lining. •• Do not permit water to collect or pond on your home site. Water gathering here will tend to either seep into the ground (loosening or expanding fill or natural ground), or will overflow into the slope and begin erosion. Once erosion is started, it is difficult to control and severe damage may result rather quickly. . Never connect roof drains, gutters, or down spouts to subsurface drains. Rather, arrange them so - that water either flows off your property in a specially designed pipe or flows out into a paved driveway or street. The water then may be dissipated over a wide surface or, preferably, may be carried away in a paved gutter or storm drain. Subdrains are constructed to take care of ordinary subsurface water and cannot handle the overload from roofs during a heavy rain. •• Never permit water to spill over slopes, even where this may seem to be a good way to prevent ponding. This tends to cause erosion and, in the case of fill slopes, can eat away carefully designed and constructed sites. - •• Do not cast loose soil or debris over slopes. Loose soil soaks up water more readily than compacted fill. It is not compacted to the same strength as the slope itself and will tend to slide when laden with water; this may even affect the soil beneath the loose soil. The sliding may clog - terrace drains below or may cause additional damage in weakening the slope. If you live below a slope, try to be sure that loose fill is not dumped above your property. 4 Never discharge water into subsurface blanket drains close to slopes. Trench drains are sometimes used to get rid of excess water when other means of disposing of water are not readily - available. Overloading these drains saturates the ground and, if located close to slopes, may cause slope failure in their vicinity. 4 Do not discharge surface water into septic tanks or leaching fields. Not only are septic tanks - constructed for a different purpose, but they will tend, because of their construction, to naturally accumulate additional water from the ground during a heavy rain. Overloading them artificially during the rainy season is bad for the same reason as subsurface subdrains, and is doubly - dangerous since their overflow can pose a serious health hazard. In many areas, the use of septic tanks should be discontinued as soon as sewers are made available. 4 Practice responsible irrigation practices and do not over-irrigate slopes. Naturally, ground cover of ice plant and other vegetation will require some moisture during the hot summer months, but during the wet season, irrigation can cause ice plant and other heavy ground cover to pull loose. This not only destroys the cover, but also starts serious erosion. In some areas, ice plant and other heavy cover can cause surface sloughing when saturated due to the increase in weight and - weakening of the near-surface soil. Planted slopes should be planned where possible to acquire sufficient moisture when it rains. 4 Do not let water gather against foundations, retaining walls, and basement walls. These walls are - built to withstand the ordinary moisture in the ground and are, where necessary, accompanied by subdrains to carry off the excess. If water is permitted to pond against them, it may seep through ADVANCED GEOTECHNICAL. SOLUTIONS, INC. - the wall, causing dampness arid leakage inside the basement Further, it may cause the foundation to swell up, or the water pressure could cause structural damage to walls 4 Do not try to compact soil behind walls or in trenches by flooding with water. Not only is - flooding the least efficient way of compacting fine-grained soil, but it could damage the wall foundation or saturate the subsoil 4 Never leave a hose and sprinkler running on or near a slope, particularly 'during the rainy season - This will enhance ground saturation which may cause damage . Never block ditches which have been graded around your house or the lot pad These shallow ditches have been put there for the purpose of quickly removing water toward the driveway, ,:street or other positive outlet. By all means, do not let wter become ponded above slopes by blocked ditches. : . . Seeding and pianting.of the slopes should be planned to achieve,as rapidly as possible, a;well- estãblish'&land deep-rooted vegetal cover requiring minimal watering. It should be the responsibility of the landscape architect to provide such plants initially and of the residents to maintain such planting Alteration of such a planting scheme is at the resident's risk I - 4 The resident is responsible for proper irrigation and for maintenance and repair of properly installed irrigation. systems,.,Leaks should be fixed immediately. Residents must undertake a program to eliminate burrowing animals This must be an ongoing program in order to promote slope stability. The burrowing animal control 'program should be conducted by a licensed exterminato and/or landscape professional with expertise in hill side maintenance. Gedtechiiical Review Due .,to the fact that soil types may vary with depth, it is recommended that plans for the construction of rear yard improvements (swimming pools, spas, barbecue pits, patios, etc), be reviewed by ,,a geotechnical engineer who is familiar with local conditions and the current standard of practice in the vicinity of your - home. In conclusion, your neighbor's slope, above or below your property, is as important to you as the slope that is within your property lines For this reason, it is desirable to develop a cooperative attitude regarding hillside maintenance, and we recommend developing a "good neighbor' policy. Should conditions develop off your property, which are undesirable tfrorh indications given above, necessary - action should be taken by you to insure that prompt remedial measures are taken Landscaping of your property is irnportantto enhance slope and foundation stability and to prevent erosion of the near surface soils. In addition, landscape'improvements should provide for efficient drainage to a controlleddischarge location downhillofrësidential improvements and soil slopes. Additionally, recommendations contained in the Geotechnical Engineering Study report apply to all future residential site improvements, and we advise that you include consultation with a. qualified professional in planning, design, and construction of any improvements Such improvements include patios, swimming pools, decks, etc., as well as building structures and all changes in the site configuration requiring earth cut or fill construction. ADVANCED GEOI[CHNICAIi SOLUTIONS, INC. ( ' ADVANCED GEOTECHNICAL SOLUTIONS, INC. 25109 Jefferson Avenue, Suite 220 GS / Murrieta, California 92562 \ / Telephone: (619) 708-1649 Fax: (714) 409-3287 NEW POINTE. COMMUNITIES, INC. April 11, 2012 16880 West Bernardo Drive, Suite 230 P/W 1201-02 San Diego, CA 92127 Report No. 1201-02-B-3 Attention: Mr. Scot Sandstrom Subject: Foundation Design Review Letter Proposed Single Family Residences, PcI 2 (1373 Magnolia Ave) and PcI 3 (1377 Magnolia Ave.) Carlsbad, California References: I) Innovative Structural Engineering (ISE) 1377 Magnolia Ave Pci 3, dated March 23, 12 (Sheets SCS, Si, & SD 1) - Innovative Structural Engineering (ISE) 1373 Magnolia Ave Pci 2, dated March 29, 2012(SheetsSCS, Si, &SDJ) Geotechnical Investigation and Foundation Design Recommendations for Proposed Single-Family Residences, Parcel 2 and 3, 1369 Magnolia Avenue, Carlsbad, California prepared by Advanced Geotechnical Solutions, Inc. 'c (AGS) dated March 21, 2012 (P/W 1201-02) Gentlemen: In accordance with your request, Advanced Geotechnical Solutions, Inc.'s (AGS) has reviewed the Foundation Plans for PcI 2 (1373 Magnolia Ave.) and PcI 3 (1377 Magnolia Ave.) prepared by Innovative Structural Engineering (ISE), dated March 29 and March 23, 2012. Specifically, AGS has reviewed sheets SCS, S1 and SDI of each plan set for conformance to the recommendations presented in the Geotechnical Investigation and Foundation Design Recommendations report (Ref. 3). Based upon our review it is our opinion that the proposed foundation designs were prepared in general accordance with the recommendations presented in the referenced report. Advanced Geotechnical Solutions, Inc. appreciates the opportunity to provide you with geotechnical consulting services and professional opinions. If you have any questions, please contact the undersigned at (619) 708-1649. Respectfully, Submitted, ,Vi RCE 46544 / RGL2344Reg. Exp. 6-30-13 Distribution: (6) Addressee p0FE rn No. 2314 . EXp6..30 7 3 °CAUFOd ORANGE AND L.A. COUNTIES INLAND EMPIRE SAN DIEGO AND IMPERIAL COUNTIES (714) 786-5661 (619) 708-1649 (619) 850-3980