Loading...
HomeMy WebLinkAbout; Carlsbad Research Center Lot 74; Soils Report; 1992-04-27- - - - .- - FOUNDATIONINVESTIGATION PROPOSEDCOMMERCIALDEVELOPMENT L~T~~OFMAP~~~~~,CARLSBADRESEARCHCENTER CARLSBAD,CALIFORNIA PREPARED FOR: S.M.A.C. 26820 HOBIE CIRCLE, SUITE B MURRIETA, CALIFORNIA 92562 PREPARED By: KG INCORPORATED 9240 TRADE PLACE, SUITE 100 SAN DIEGO, CALIFORNIA 92 I26 APRIL 27, 1992 JOB NO. 05-8829-001-00-00 LOG NO. 2-1145 a KG - '"iizcolporatd - - April 27, I992 S.M.A.C. 26820 Hobie Circle, Suite B Murrieta, California 92652 Attention: Mr. Robert Berry Job No.05-8829-001-00-00 Log No. 2-l 145 SUBJECT: FOUNDATION INVESTIGATION Proposed Commercial Development Lot74ofMapl1811 Carlsbad Research Center Carlsbad, California Gentlemen: As requested, we have completed our foundation investigation for the proposed 20,000 square foot building Planned for Lot 74, of Map 11811, at the Carlsbad Research Center. Our findings and recommendations are presented herein. In our opinion, the primary site condition which is likely to impact the proposed development is the presence of near surface expansive soils. Recommendations regarding this and other site conditions impacting the proposed development are provided in the attached report. If you have any questions after reviewing our report, please do not hesitate to contact the undersigned at your convenience. This opportunity to be of professional service is sincerely appreciated. Very truly yours, Dwight R. Haggard E.G. 1178 Vice President (Operations) San Diego Region ADE/HW/DRH/pb/gof - Geotechnical Services, Construction Inspection and Testing TABLE OF CONTENTS 1.0 INTRODUCTION ............. . . . . . . . I 1.1 Authorixation ........... . . . . . . . . . 1 1.2 Scope of Services .......... . . . . . . . I 2.0 PROPOSED DEVELOPMENT ...................................................... 2 3.0 SITE DESCRIPTION.. ........................................................... 2 - 4.0 SITE INVESTIGATION . . . . . . . . . . . . . . . 4.1 Field Exploration . . . . . . . . . . . . . . . 4.2 Laboratory Testing . . . . . . . . . . . . . - 5.0 SUBSURFACE CONDITIONS . . . . . . . . . . . . . . 5.1 General . . . . . . . . . . . . . . . . . . . 5.2 FiII . . . . . . . . . . . . . . . . . . . . 5.3 Santiago Formation . . . . . . . . . . . . . 5.4 Point Loma Formation . . . . . . 5.5 Santiago Peak Volcanics . . . . . . . . - 5.6 Groundwater . . . . . . . . . . . . . 6.0 SEISMICITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - 6.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2 Earthquake Effects . . . . . . . . . . . . . . . . . . . . . 6.2.1 Surface Fault Rupture . . . . . . . . . . . . . . . - 6.2.2 Ground Accelerations . . . . . . . . . . . . . . . . . . 6.2.2 Seismically Induced Settlement and Liquefaction . 6.2.3 Other Hazards . . . . . . . . . . . . . . 7.0 CONCLUSIONS AND RECOMMENDATIONS . 7.1 General .......................... 7.2 Grading and Earthwork .............. - 7.2.1 General ..................... 7.2.2 Site Preparation ............... 7.2.3 Fill Compaction .............. 7.2.4 Trench Backfill ............... 7.3 Slope Stability ...................... 7.4 Site Drainage ...................... 7.5 Foundation Recommendations ......... 7.5.1 General ..................... 7.5.2 Foundations on Non-expansive Cap 7.5.3 Post-Tensioned Slabs ........... 7.5.4 Moisture Conditioned Building Pad 7.5.5 Settlement ................... 7.5.6 Lateral Load Resistance ........ 7.5.7 Slabs-On-Grade .............. 7.5.8 Foundation Observation ........ 7.6 Earth Retaining Structure 7.7 Reactive Soils ...................... 7.8 Pavement ......................... 7.9 Review of Plans .................... 7.10 Geotechnical Observation ............. 8.0 LIMITATIONS OF INVESTIGATION ......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2 3 3 3 4 4 4 . 4 5 5 5 . . 5 5 . . 6 6 7 8 8 9 . 9 . 9 . 10 11 11 11 12 . 12 . I2 13 13 . 13 14 14 15 16 17 17 18 18 ATTACHMENTS Figures 1 - 2 3 4 Appendices A B C - D Table 1 Plate 1 Location Map Regional Fault Map Retaining Wall Backdrain Detail - Crushed Rock Alternative Retaining Wall Backdrain Detail - Composite Drain Alternative References Field Exploration Laboratory Testing Program Standard Guidelines for Grading Projects Seismicity of Major Faults Geotechnical Map FOUNDATION INVESTIGATION LOT 74 of Map 11811, CARLSBAD RESEARCH CENTER CARLSBAD, CALIFORNIA 1.0 INTRODUCTION This report presents the results of our Foundation Investigation performed for the proposed commercial development on Lot 74, of Map 11811, Carlsbad Research Center. The purpose of this investigation was to explore and evaluate the subsurface conditions at the site with respect to the proposed development, and to provide recommendations for site preparation, as well as, geotechnical design parameters for the proposed project. The location of the subject site is shown on the Location Map provided on Figure 1. 1.1 Authorization This investigation was conducted in accordance with the authorization of Mr. Robert Berry of S.M.A.C. The scope of services performed was consistent with our Proposal Number SDP2-6037, dated January 24, 1992. 1.2 Scooe of Services Our scope of services for this investigation included the following: a) Review of the referenced geotechnical reports and literature pertinent to the project area (Appendix A). b) Drilling, logging, and sampling of 4 eight-inch diameter hollow stem auger borings, to a maximum depth of 41 feet. c) Laboratory testing of selected samples to evaluate the pertinent engineering characteristics of the site soils . d) Evaluation of the groundshaking potential resulting from seismic events occurring on significant faults in the area. e) Engineering analysis to evaluate and provide recommendations regarding the settlement potential of the soils, and other geotechnical concerns. ADAPED FRON U.S.&S. 7.5’ 5ANLusev -LE (1975) - LOCATION MAP - LOT 74 JOE NO.: DATE: FIOURE: - 05-8829-001-00-00 APmL 1992 1 ICG Incorporated - - - - - -~ - S.M.A.C. April 27, 1992 Job No. 05-8829-001-00-00 Log No. 2- 1145 Page 2 f) Preparation of this geotechnical report including: i. Development of geotechnical criteria for earthwork on the site, site preparation, soil compaction criteria, and remedial grading. ii. Recommendations for appropriate foundation systems and geotechnical criteria for design of foundations, slabs, and retaining walls. 2.0 PROPOSED DEVELOPMENT It is our understanding that the proposed development will consist of a one to two story, concrete tilt-up structure with slab-on-grade. The anticipated design column loads are assumed to be less than 100 kips and wall loads less than 5 kips per linear foot. In addition, asphaltic concrete paved parking areas and access driveways are planed. The site has been previously rough graded by our company, formerly, San Diego Geotechnical Consultants Inc., (Reference 2), therefore only a minor amount of grading is assumed necessary. 3.0 SITE DESCRIPTION The project site was previously graded as Lot 74 of Map 11811, Carlsbad Research Center, Reference 2. The site consists of an approximately level lot located on the westerly corner of Van Allen Way. Site drainage is provided by sheet flow toward the west. Review of the previous geotechnical reports indicates that the site is entirely underlain by compacted fill and the building pad is underlain by 20 to 30 feet of fill. 4.0 SITE INVESTIGATION 4.1 Field Exoloration The field exploration for this investigation was performed on March 10, 1992. The investigation consisted of site reconnaissance, and subsurface exploration by our geotechnical staff. __ -. - S.M.A.C. April 27, 1992 Job No. 05-8829-001-00-00 Log No. 2-l 145 Page 3 The subsurface exploration consisted of four E-inch diameter, hollow stem auger borings, drilled witha truck-mounted continuous flight auger. Relatively undisturbed samples were taken using a standard split spoon sampler and a modified California sampler. Bulk samples of representative soils were also collected. The borings were excavated to a maximum depth of 41 feet. The borings were logged and then backfilled. Lines delineating the change between soil types on the boring logs, Appendix B, were determined from interpolation betweens sample locations and are therefore approximations. Transitions may be abrupt or gradational. Logs of the borings are included in Appendix B. The approximate boring locations were mapped in the field and are shown on the grading plan (Plate I). Locations were estimated by pacing; survey accuracy should not be assumed. 4.2 Laboratorv Testing Representative samples of the on-site soils, encountered during the field exploration, were submitted to our laboratory for testing. Tests were performed in accordance with the test methods of ASTM, UBC, and/or other accepted standards. Results and descriptions of the laboratory tests performed are included in Appendix C. 5.0 SUBSURFACE CONDITIONS 5.1 General The site is underlain by approximately twenty to thirty feet of compacted fill which was placed over bedrock of the Santiago Formation, Santiago Peak Volcanics or Point Loma Formation. The fill was placed during mass grading for the Carlsbad Research Center. Description of the units are described below. - - - - - - r- - - - - ,- S.M.A.C. April 27, 1992 Job No. 05-8829-001-00-00 Log No. 2-1145 Page 4 Site preparation and placement of compacted fill at the subject site is documented in our As-Graded Geotechnical Report (Reference 2, Appendix A). The fill appears to have been derived primarily from cuts in the Point Loma Formation and consists of light olive to gray, moist, stiff, silty clay. The fill is considered suitable for foundation bearing support, but is critically expansive. Likewise, mitigation recommendations are considered necessary. 5.3 Bntiaeo Formation The Eocene age Santiago Formation underlies the fill in approximately one-third of the site, near the southern property boundary. The Santiago Formation, as observed in our borings, is a massive to thick-bedded silty to clayey sandstone. 5.4 Point Loma Formation The Cretaceous age Point Loma Formation underlies the fill in approximately one- third of the site, near the northern property boundary. As encountered, the Point Loma Formation consisted mainly of highly plastic siltstone with minor amounts of fine sand. 5.5 Santiaao Peak Volcanics The Jurassic age Santiago Peak Volcanics as reported, reference 2, unconformably underlie the Santiago Formation near the western boundary of the site. The Santiago Peak Volcanics are mildly metamorphosed volcanic, or metavolcanic rocks. Regionally the Santiago Peak Volcanics vary from basalt to rhyolite but on-site they are predominantly andesite. -. _- - - - - S.M.A.C. April 27, 1992 Job No. 05-8829-001-00-00 Log No. 2-l 145 Page 5 5.6 Groundwater Groundwater was not encountered in any of our borings. During periods of heavy rain or drought, the water table may rise or fall, respectively. It should be recognized that excess irrigation on the project site or on adjacent sites can cause a perched groundwater condition to develop at some future date. This typically occurs at underlying contacts with less permeable materials, such as the interface that exists between the fill and the underlying bedrock. Because the prediction of the location of such conditions is not possible, related problems are typically mitigated if and when they occur. 6.0 SEISMICITY 6.1 General The site is considered to be a seismically active area, as can all of southern California. There are, however, no known active faults either on or adjacent to the project site. Figure 2 shows the known active faults and major earthquake epicenters in the region and their geographic relationship to the site. Because these active faults are at a substantial distance, the seismic risk at this site is considered to be low to moderate in comparison to many parts of southern California. Most seismic hazards at the site are a consequence of ground shaking caused by events on distant, active faults. The hazard level is sufficient to place the area in seismic risk zone 3 as defined in the Uniform Building Code. In addition to the information on Figure 2, Table 1 lists the active faults within 63 miles (100 kilometers) of the site and the maximum probable earthquakes on those faults. 6.2 Earthauake Effecb 6.2.1 Surface Fault Ruoture In our opinion, the risk of surface rupture at the project site is low as, no known active faults or potentially active faults cross the site. - - - - - - - - TABLE 1 SEISMICITY FOR MAJOR FAULTS WITHIN 100 KILOMETERS OF SITE Maximum Credible Maximum Probable Earthauake’ Earthauake’ Peak Peak Bedrock Bedrock FAULT DISTANCE ML2 Acceleration’ ML’ Accelerations Rose Canyon 9 miles WSW 7.0 0.37g 6.4 0.3og Coronado Banks 22 miles SW 7.0 0.19s 6.5 0.14g San Clemente 56 miles SW 7.5 0.08g 7.3 0.07g Elsinore 22 miles NE 7.5 0.26g 7.0 0.19g San Jacinto 45 miles SW 7.5 0.12g 7.5 0.12g San Andreas 66 miles NNE 7.5 0.06g 7.5 0.06g Newport/Inglewood 44 miles NW 7.0 0.09s 6.5 0.06G 1 The maximum credible earthquake is the largest earthquake that appears capable of occurring under the presently known tectonic framework. The maximum probable earthquake is the largest earthquake event which has an 80% probability of not being exceeded in 100 years. 2 Values are local magnitudes, taken from Jennings (1975). and Greensfelder (1974). 3 From Seed and Idriss (1982). 4 Values are local magnitudes, generally taken from Seismic Safety Study for City of San Diego (1974). 5 Potentially active fault. I I I I I I I I I I I I I 1 I I 1 REGIONAL FAULT MAP 06 NO.: DATE: FIGURE: 05-8829-001-00-00 APRIL 1992 2 ICG Incorporate - - - - - - - - - - - - S.M.A.C. April 27, 1992 Job No. 05-8829-001-00-00 Log No. 2-l 145 Page 6 6.2.2 Ground Accelerations In our opinion, based on the information now available, the most significant event likely to affect this project would be an earthquake on the Rose Canyon fault. Recent work on the Rose Canyon fault zone has indicated that strands within the zone are active (Appendix A, reference 6). A single trace has been shown to offset topsoil in one location, and appears to have created topographic features common in active faulting (offset drainages, pressure ridges, enclosed depressions and fault scarps). The age of the most recent movement, the fault’s recurrence interval (expected period between major earthquake events), and the relationship between the active trace and other faults within the fault zone have not yet been established. It should be noted that the California Division of Mines and Geology (CDMG) could establish Alquist-Priolo Special Studies Zones along the fault at any time. Upgrading the San Diego area from seismic zone 3 to seismic zone 4 would likely follow designation of Special Studies Zones by the State of California. We have reviewed the existing information available regarding the fault and conclude that for the Rose Canyon fault, a magnitude 7.0 earthquake is an appropriate maximum credible event for a 20 mile rupture length (offshore La Jolla to Coronado Bridge). A maximum probable event of magnitude 6.4 is hypothesized for the Rose Canyon fault. We estimate a 6.4 magnitude event would generate a peak bedrock acceleration within the project area of about 0.3Og. 6.2.2 Seismically Induced Settlement and Liauefaction Because of the high relative densities of both the bedrock materials and the compacted fill which underlies the site, the potential for liquefaction or seismically induced settlements are considered low. - S.M.A.C. April 27, 1992 Job No. 05-8829-001-00-00 Log No. 2-l 145 Page 7 6.2.3 Other Hazards Because the site is generally flat the potential for seismically induced slope failures are considered nil. Due to the site’s elevation above sea level, hazards such as tsunamis, or seiches are not considered hazards. - - - - - - - - - - - - - - - - - - S.M.A.C. April 27, 1992 7.0 CONCLUSIONS AND RECOMMENDATIONS 7.1 General Job No. 05-8829-001-00-00 Log No. 2-l 145 Page 8 No geotechnical conditions were apparent during our investigation which would preclude the site development as planned. The site condition which has the most severely impact the development are the critically high expansion potential of the prevailing on-site soils. The expansion potential exceeds the range in which the more typical recommendations on southern California can be used. Special foundation design and/or site preparation is recommended to decrease the likelihood of foundation and slab cracking due to expansive heave. We recommend that one of the following alternatives be employed to decrease the risk of movement of foundations and slabs. They are given in order of increasing risk. a. Cap the building area with imported, non-expansive soil to a depth of at least three feet below the bottom of the footings. b. Use a post-tensioned slab system directly on the on-site soils. C. Moisture condition the on-site soil and use a reinforced foundation and slab. The remainder of Section 7.0 presents our recommendations in detail. These recommendations are based on empirical and analytical methods typical of the standard of practice in southern California. If these recommendations appear not to cover any specific feature of the project, please contact our office for additions or revisions to our recommendations. - S.M.A.C. April 27, 1992 Job No. 05-8829-001-00-00 Log No. 2-1145 Page 9 - - - - 1.2 Gradina and Earthwork 7.2. I General Grading and earthwork should be done in accordance with the “Standard Guidelines for Grading Projects” attached to this report as Appendix D, and with Chapter 70 of the Uniform Building Code. Where special recommendations in the body of this report conflict with the guidelines in Appendix D, the recommendations in the report should govern. 7.2.2 Site Prwaration i. Non-exoansive Cae: If the option of capping the building areas with imported, non-expansive fill is chosen, the capped area should include the area within a perimeter of five feet outside the building limits. The existing soil in this area should be excavated to a depth of at least three feet below footing bottoms. The excavation bottom should be observed by our personnel. The excavation should then be brought to the design grade using uniformly compacted lifts of imported soil. The import should consist of well graded soil having an expansion index of 20 or less when tested in accordance with UBC Standard No. 29-2. Proposed import material should be tested for expansion potential by our office prior to importing. It may also be desired to use a similar recommendation in areas of curb, gutter, sidewalks and exterior slabs. This condition is further discussed in Section 7.5.7. ii. Post-Tensioned Slabs; If post-tensioned slabs are used for the structure, then special site preparation of the building area is not considered necessary. Normal site preparation should apply, which consists of removal of any surface vegetation and debris, scarification of the upper 12 inches of soil, wetting the soil to approximately optimum moisture conditions, and compacting them to at least 90 percent relative compaction. - S.M.A.C. April 21, 1992 .- - - - - - - - - Job No. 05-8829-001-00-00 Log No. 2-1145 Page 10 iii. Moisture ConditioninK If the moisture conditioning option is chosen, the subgrade soil within the building area (as defined in option i.) should be brought to at least five percentage points over optimum moisture or to 125% of optimum moisture, whichever is greater, in the upper 2 feet of design subgrade. iv. Other Oottonc As stated previously, the moisture conditioning recommendation is considered to have more associated risk than the other two portions. An alternative to moisture treating the existing soil which would have less risk is to use lime treatment. In our opinion, this option would have a similar risk to the imported non-expansive option. Typical lime treatment would involve the thorough mixing of three to five percent of hydrated lime into the existing soil. More specific recommendations can be provided upon request. v. Privewav and Par- Site preparation of the parking lot areas should consist of scarification/reworking and recompaction of the upper 12 inches. 7.2.3 Fill Comoaction All fill and backfill to be placed in association with site development should be accomplished at slightly over optimum moisture conditions and using equipment that is capable of producing a uniformly compacted product. The minimum relative compaction recommended for fill is 90 percent of maximum density based on ASTM D 1557 (modified Proctor). Sufficient observation and testing should be performed by the geotechnical consultant so that an opinion can be rendered as to the compaction achieved. Representative samples of imported material and on-site soils should be tested by the geotechnical consultant in order to evaluate the maximum density, optimum moisture content, and where appropriate, shear strength, consolidation soluble sulfate, and expansion characteristics of the soil. - - - - - - - - - S.M.A.C. April 21, 1992 Job No. 05-8829-001-00-00 Log No. 2- 1145 Page 11 During grading operations, soil types other than those analyzed in the geotechnical reports may be encountered by the contractor. The geotechnical consultant should be notified to evaluate the suitability of these soils for use as fill and as finish grade soils. 7.2.4 Trench Backfill All trench backfill should be compacted by mechanical means in uniform lifts of 8 to 12 inches. The backfill should be uniformly compacted to at least 90 percent of ASTM D 1557. 7.3 Slooe Stability Significant slopes do not exist on the site and slope construction is not proposed. 7.4 Site Drainage Foundation and slab performance depends greatly on how well the runoff waters drain from the site. This is true both during construction and over the entire life of the structure. The ground surface around structures should be graded so that water flows rapidly away from the structures without ponding. The surface gradient needed to achieve this depends on the prevailing landscape. In general, we recommend that pavement and lawn areas within five feet of buildings slope away at gradients of at least two percent. Densely vegetated areas should have minimum gradients of at least five percent away from buildings in the first five feet. Densely vegetated areas are considered those in which the planting type and spacing is such that the flow of water is impeded. Roof drains should be carried across all backfilled areas and discharged at least 10 feet away from structures. Planters should be built so that water from them will not seep into the foundation, slab, or pavement areas. Site irrigation should be limited to the minimum necessary to sustain landscaping plants. Should excessive irrigation, waterline breaks, or - - - - - - - S.M.A.C. April 27, 1992 Job No. 05-8829-001-00-00 Log No. 2- 1145 Page 12 unusually high rainfall occur, saturated zones or “perched” groundwater may develop in fill soils. 7.5 Foundation Recommendation8 7.5.1 General Expansive soils on the site create the risk of future differential movement of foundations and interior slabs. The previously discussed recommendations will serve to mitigate the future movements. Our recommendations are considered generally consistent with methods typically used in southern California. Other alternatives may be available. The foundation recommendations herein should not be considered to preclude more restrictive criteria of governing agencies or by the structural engineer. The design of the foundation system should be performed by the project structural engineer, incorporating the geotechnical parameters described in the following sections. Movement of exterior slabs, curbs and gutters must be accepted when building on highly expansive soils. In excess of one inch of differential movement is possible. Reinforcement and control joints will reduce cracking associated with such movement. If such movement are not acceptable, then a non- expansive cap or lime treatment should be used. 7.5.2 Foundations on Non-exnansive Cm If the building area is capped with non-expansive soils as recommended in Section 7.2.2, the following foundation design parameters should be applicable. Allowable Soil Bearing: Minimum Footing Width: Minimum Footing Depth: 3,000 psf (allow a one-third increase for short term wind or seismic loads) 12 inches 18 inches S.M.A.C. April 27, 1992 Job No. 05-8829-001-00-00 Log No. 2-l 145 Page 13 - - - - 7.5.3 7.5.4 Minimum Reinforcement: Two No. 4 bars at both top and bottom in continuous footings, or design as simply supported beam capable of supporting the applied loads over a span of 5 feet, whichever is greater Post-Tensioned Sla& A structurally designed, post-tensioned slab-on-grade may be used to mitigate the effects of soil expansion. The system consists of a slab reinforced with tendons which are tensioned after the concrete is cured, in conjunction with conventionally reinforced stiffening beams. Moisture Conditioned Buildinn Pad The following design parameters are contingent upon moisture conditioning the soils within the building areas as discussed in Section 7.2.2. Allowable Soil Bearing: 2,500 psf (allow a one-third increase for short-term wind or seismic loads) Minimum Footing Width: Minimum Footing Depth: Minimum Reinforcement: 12 inches 18 inches two #5 bars at both top and bottom in continuous footings, or design as simply supported beam capable of supporting the applied loads over a span of 8 feet, whichever is greater. Column loads should not be supported on isolated pad footings, but should bear on continuous grade beam footings tied into the continuous footings. 7.5.5 Settlement The anticipated total and differential settlement for the proposed structure should be within tolerable limits provided that the recommendations of this report are followed. In general, total settlements are estimated to be less than one inch, and differential settlement is expected to be less than 3/4-inch. It .~ - - - .- - -- - a. -,. b. - .- -.. S.M.A.C. April 27, 1992 Job No. 05-8829-001-00-00 Log No. 2-1145 Page 14 is recommended that we review the actual foundation plans to evaluate the footing configurations and loading conditions. 7.5.6 Lateral Load Resistance Lateral loads against structures may be resisted by friction between the bottoms of footings and supporting soil. A coefficient of friction of 0.3 is recommended for the on-site fill soils. Alternatively, a passive pressure of 300 pcf is recommended. If friction and passive pressure are combined, the passive pressure value should be reduced by one-third. 7.5.7 Slabs-On-Grade Interior Slabs; Slabs should be designed by a structural engineer for the anticipated loading based on a modulus of subgrade reaction of 250 kips/cf for slabs on compacted non-expansive imported soils, and 125 kips/cf for moisture conditioned native soil. In consideration of the expansive potential of the soil, slabs on moisture conditioned subgrade should be at least six inches in thickness and should be reinforced with at least #3 reinforcing bars on 12 inch centers in both directions. Slabs on a non-expansive soil cap should be at ieast five inches in thickness and should be reinforced with at least #3 reinforcing bars on 18 inch centers in both directions. Crack control joints should be provided in all slabs, spaced on 15 to 20 foot centers. Moisture Protection for Slabs Concrete slabs resting on soil ultimately cause the moisture content of the underlying soils to rise in the underlying soil. This results from continued capillary rise and the ending of normal evapotranspiration. Because normal concrete is permeable, the moisture will eventually penetrate the slab unless some protection is provided. This may cause mildewed carpets, lifting or discoloration of floor tile, or similar problems. To minimize these problems, suitable moisture protection measures should be used. Various alternatives exist, including concrete toppings or additives and S.M.A.C. April 27, 1992 - - - __ Job No. 05-8829-001-00-00 Log No. 2-1145 Page 15 synthetic moisture-resistant membranes. Information on the product usage, installation and warranty should be obtained from the manufacturer if these products are used. The effectiveness of such measures can be improved by installing a capillary break under the membrane or damp-proofed slab. If a waterproofing membrane is installed beneath the concrete slab, at least one inch of sand should be placed between the membrane and the slab to decrease the likelihood of curing problems in the concrete. c. Exterior Sla& Some movement and cracking should be expected in exterior improvements such as slabs, sidewalks, and curbs and gutters which are place directly over the on-site expansive soil. One inch of differential movement is not unusual, and more is possible. Reinforcement and control joints will reduce the cracking and movement potential. As a minimal recommendation, slabs should be at least five inches in thickness and should be reinforced with at least #3 (or larger) steel bars on 24 inch centers in both direction. Crack control joints should be provided in all slabs, spaced on IO-foot (or less) centers in both directions. Differential movement between curb and sidewalk can be reduced by dowelling the sidewalk into the curb. The sidewalk typically will rotate at the hinge point next to the curb. Differential movement and cracking can be decreased if at least two feet of non-expansive soil is placed for slab subgrade. Lime treatment of the subgrade should also be effective. 7.5.8 Foundation Observation All foundation excavations should be observed by the geotechnical consultant prior to placement of forms, reinforcement, or concrete. The observation will confirm that the soil conditions are as anticipated and that the intent of our recommendations have been complied with. The excavations should be trimmed to design dimensions and should be cleared of all loose slough. - - - - - - - S.M.A.C. April 27, 1992 Job No. 05-8829-001-00-00 Log No. 2- 1145 Page 16 7.6 Earth Retaining Structures Because of the potential for high wall pressures resulting from soil expansion, it is not recommended that walls be backfilled with on-site expansive soils. Non-expansive imported soil should be sued in the zone defined by a I:1 plane sloping back from the base of the wall. Cantilever retaining walls backfilled with non-expansive soil should be designed for an active earth pressure approximated by an equivalent fluid pressure of 40 pounds per cubic foot. This active pressure should be used for walls free to yield at the top at least 0.1 percent of the wall height (unrestrained). For walls restrained so that such movement is not permitted, an equivalent fluid pressure of 65 pcf should be used, based on at-rest soil conditions. The above pressures do not consider any sloping backfill, surcharge loads or groundwater forces. If any of these conditions exist, they will increase lateral pressures on walls. We should be contacted for further recommendations in such cases. Retaining wall backfill should be compacted to at least 90 percent relative compaction, based on ASTM D 1557. Backfill should not be placed until walls have achieved adequate structural strength. Heavy compaction equipment which could cause distress to walls should not be used. To prevent the buildup of hydrostatic pressure, due to infiltration of irrigation or rainwater, we recommend the installation of drains behind all retaining walls. Suggested drain details are shown on Figures 3 and 4. 7.7 Reactive Soil8 Laboratory testing indicates that the soil should not be detrimental to Type II cement. Results of subsurface content tests are presented in Appendix C. -., .-. .- _ - RElAlNlND WALL\ COMPACTED BACKFILL- FILTER FA0RIC LIIRAFI 140N\ OR EQUWALENT 314’ CRUSNED AQQREOATE\ 12. MINIMUU- +3iOPE 2% AWAY FROM WALL IN-PLACE SOIL OR BEDROCK bdINIMUU 2’ DIA. PERFORATED PIPE :OMPACTED SO1 IN-PLACE SOIL OR BEOROCK ERMEABLE CLAY LY USE OlTCHr I DETAIL OF WEEP HOLES (MAY BE USED INSTEAD OF DRAIN PIPE IF SEEPAGE OUT OF WEEPHOLE IS ACCEPTABLE) TOP OF WALL DETAIL FOR SLOPING BACKFILL I l SUBDRAIN SHOULD HAVE A FALL OF AT LEAST 1.6% l SUBORAIN SHOULD HAVE WEEP HOLES. A FREE QRAVITY OUTFALL OR A SUMP AN0 PUMP. l INITALLATION OF THE DRAIN SHOULD SE OBSERVED BY THE SOILS ENOINIIEII. l PLACE PIPE (IF USED) WlTH PERFORATIONS FACING DOWNWARQ. NOT TO BCAL RETAINING WALL BACKDRAIN DETAIL-CRUSHED ROCKY AL;IERNAm JOa NO.: lOAlES (FIQUA& a. I 054829-901-09-00 I APRIL 1992 I ;I -SLOPE 2% AWAY FROM WALL RETAIWlNO WAC COMPACTED BACKFILL FABRIC FLAP MIRAORAIN SO00 OR EQUIVALENT IN-PLACE SOIL OR BEDROCK FAllRlC FLAP AR INIYUM 3’ DIA. PERFORATED - ,- - IN-~N-;“c’K SOIL OR WEE? MOLE8 I I DETAIL OF WEEP HOLES TOP OF WALL DETAIL FOR SLOPING BACKFILL (MAY BE USED INSTEAD Of DRAIN PIPE IF BEEPAQE OUT OF WEEPHOLE IS ACCEPTABLE) -~ I 0 8UBORAlN BNOULO HAVE A FALL OP AT LEA81 l-KS. I I 0 ORAINAGE MAT SWOULD BE aLUE0 OR NAILED t0 WALL. AN0 SPLICED IN AOCOROANCE WITH THE MANUPACTURER’O REooMUENOATION8. l FABRIC SIDE OF DRAIN BOAR0 SHOULD BE PLACED AWAY FROM WALL. l fll~Op”u^:“p 8HOULO HAVE WEEP HOLEB. A FRl?E QRAVITY OUTFALL. OR A SUMP l ~INSTALLATION OF THE ORAIM BHOULO BE OSIIERVEO BY THE SOILS ENQINEER. l PLACE PIPE (IF USED) WITH PERFORATIONI) FACtMa DOWNWARD. S.M.A.C. April 27, 1992 lob No. 05-8829-001-00-00 Log No. 2-l 145 Page 17 7.8 Pavement Testing of the existing, near-surface silty clays, which are anticipated for subgrade soil for pavement areas indicates an R-value of less than 5. The actual R-value of the pavement subgrade should be determined after grading is complete. Traffic was assumed to fall into two categories: I) Light traffic areas and passenger car parking (Traffic Index = 4.0). and 2) Access drives and truck routes (Traffic Index = 5.0). Based on these assumptions, the recommended pavement sections are as follows: - PAVEMENT SECTIONS Traffic Index Parking Areas TI = 4.0 Asphaltic Concrete Thickness 3 inches Aggregate Base Thickness 7 inches Driving Lanes TI = 5.0 4 inches 10 inches - - The upper 12 inches of pavement subgrade should be scarified, brought to approximately optimum moisture content, and compacted to at least 95 percent of ASTM D1557. Aggregate base should conform to Section 26 of the California Department of Transportation Manual, and should be uniformly compacted to at least 95 percent relative compaction. 1.9 Review of Plans When the grading plans and foundation plans are developed, they should be forwarded to the geotechnical consultant for review. The recommendations of this report are based on assumptions regarding the proposed development. Our review will confirm these assumptions and evaluate if the intent of the recommendations of this report have been complied with. - _. S.M.A.C. April 27, 1992 7.10 Geotechnical Observation Job No. 05-8829-001-00-00 Log No. 2-1145 Page 18 KG Incorporated personnel should continuously observe the grading and earthwork operations and foundation excavations for this project. Such observations are essential to identify field conditions that differ from those anticipated by preliminary investigations, to adjust designs to actual’field conditions, and to determine that the grading is in general accordance with the recommendations of this report. The recommendations contained in this report are contingent upon observation and testing being performed by ICG Incorporated. Our personnel should perform sufficient testing of fill during grading to support the geotechnical consultant’s professional opinion as to compliance of the fill with compaction requirements. 8.0 LIMITATIONS OF INVESTIGATION Our investigation was performed using the degree of care and skill ordinarily exercised, under similar circumstances, by reputable geotechnical consultants practicing in this or similar localities. No other warranty, expressed or implied, is made as to the conclusions and professional opinions included in this report. The samples taken and used for testing and the observations made are believed representative of the project site; however, soil and geologic conditions can vary significantly between borings. As in most projects, conditions revealed by excavation may be at variance with preliminary findings. If this occurs, the changed conditions must be evaluated by the geotechnical consultant and additional recommendations made, if warranted. This report is issued with the understanding that it is the responsibility of the owner, or of his representative, to ensure that the information and recommendations contained herein are brought to the attention of the necessary design consultants for the project and incorporated into the plans, and the necessary steps are taken to see that the contractors carry out such recommendations in the field. .- - __ - S.M.A.C. April 27, 1992 Job No. 05-8829-001-00-00 Log No. 2-l 145 Page 19 This firm does not practice or consult in the field of safety engineering. We do not direct the contractor’s operations, and we cannot be responsible for other than our own personnel on the site. The findings of this report are valid as of the present date. However, changes in the condition of a property can occur with the passage of time, whether due to natural processes or the work of man on this or adjacent properties. In addition, changes in applicable or appropriate standards of practice may occur from legislation or the broadening of knowledge. Accordingly, the findings of this report may be invalidated wholly or partially by changes outside our control. Therefore, this report is subject to review and should not be relied upon after a period of three years. Hantoro Walujono, Senior Engiy CORPGRAT-ED Registration Expires: 6-30-92 Vice President (Operations1 . . Q GC. JW Amer D. Espili Patrick A. Thomas Project Engineer Project Geologist - HW/ADE/DRH/pb/gof Job No: 05-8829-001-00-00 APPENDIX A REFERENCES Log No: 2-l 145 .- - - - - - Job No: 05-8829-001-00-00 References Log No: 2- I145 Page A-2 1. California Division of Mines and Geology, 1975, recommended Guidelines for Determining the Maximum credible and the Maximum Probable Earthquakes: California Division of Mines and Geology Notes, Number 43. 2. San Diego Geotechnical Consultants, Inc., “As-Graded Geotechnical Report Carlsbad Research Center, Phases III, IV and V, Carlsbad, California”, dated April 1, 1988, Job No: 05-2863-006-00-10, Log No: 8-1117. 3. Greensfelder, R.W., 1974 Maximum Credible Rock Acceleration From Earthquakes in California: California Division of Mines and Geology Map Sheet 23. 4. Jennings, C.W., 1975, Fault Map of California 1:750,000, California Division of Mines and Geology. 5. Seed, H.B., and Idriss, I.M., 1982, Ground Motions and Soil Liauefaction durina Earthauakes; Earthquake Engineering Research Institute, Monograph Series, 134~. 6. Lindvall, S.C., Rockwell, T.K., Lindvall, C.E., 1990, “The Seismic Hazard of San Diego Revised: New Evidence for Magnitude 6+ Holocene Earthquakes on the Rose Canyon Fault Zone”, h proceedings of Routh U.S. National Conference on earthquake engineering, Palm Springs, California (volume I): Earthquake Engineering Research Institute, p. 679-699. - - - - ..- .- - - - - - Job No: 05-8829-001-00-00 APPENDIX B FIELD EXPLORATION PROGRAM CONTENTS I. Figure B-O 2. Field Exploration Procedures 3. Figures B-2 through B-6, Logs of Borings Log No: 2-1145 !ks Key to Logs B-l .- Job No: 05-8829-001-00-00 Log No: 2-l 145 Page B- 1 - - B-l. B-2. B-3. B-4. B-5. B-6. B-7. B-8. FIELD EXPLORATION PROCEDURES Subsurface conditions were explored during the investigation by drilling 4 borings to depths ranging from 16 feet to 41 feet below the existing grade. The locations of the borings are shown on the attached Cieotechnical Map, Plate I. Borings were drilled with an &inch diameter hollow stem auger boring, truck-mounted continuous flight auger. The Key to Logs and Logs of Borings B- 1 to B-4 are included as Figures B-O through B-6. Field operations were conducted in March 10, 1992 under the supervision of our Field Geologist who logged the soils and obtained bulk, and relatively undisturbed samples for identification and laboratory testing. The weight of the hammer, the height of drop and numbers of blows per foot of penetration were observed and noted. Drill holes were located in the field by pacing, working from the locations provided on a map. Elevations were determined by interpolation between contours on the 20-scale plan. Groundwater was not encountered in any of the borings as indicated on the Logs of Borings. The borings were backfilled with drill cuttings. Relatively undisturbed samples were obtained using a standard split spoon sampler or a 3-inch outside diameter California Sampler lined with brass rings each 1 inch long and with 2-l/2 inch inside diameter. The brass rings were transferred into a plastic bag and sealed in a plastic tube immediately upon extraction from the boring. The soils were classified based on field observations and laboratory tests. The classification is in accordance with the Unified Soil Classification System (Figure B-O). Stratification lines on the logs represent the approximate boundaries between predominant soil types. Minor layers of differing material types may be contained within the strata, and a gradual transition should be expected between strata. - - .- - - - - .- - DEFINITION OF TERMS PRIMARY DlVlSlONS SECONDARY OWlSIONS HIQHLY ORQANIC SOILS aaa Pt l ..,.Ilnaw--U GRAIN SIZES SILTS AND CLAYS SAND I GRAVEL ma! ( Ytel”” ( CO.“SI 1 Fl”L 1 COIIsL COBBLES BOULDERS 1 a00 .O 10 . a#.- 3. li UI 011- *samI. ama CUA” SQ”Am ama o,a*IO, RELATIVE DENSITY CONSISTENCY WFI 1 CO~WCTION “I - “0 “CCOVE”” KEY TO LOGS 08 NO.: DATE: FIQURE: 05-8829-001-00-00 B-O - - .,- - - - .- )ATE OBSERVED: 3-10-92 METHOD OF DRILLING: 8" Hollow Stem Auger AOGGEDB I 20.1 17.7 iiT 11.6 105 11c 107 112 .EVATION:~~~' LOCATION: See Mat) LOG OF BORING NO. B-l Sheet 1 of 2 - DESCRIPTION nL: Medium brown silty CLAY, damp to moist, firm to very stiff .--_----_-_-__-__-----------~ Light olive brown silty CLAY, damp to C moist, stiff, fill is from Point Loma Formation cut .--_-_--_-_____-__-_--------~ , Light olive brown to medium gray silty CLAY, damp, stiff 1 .---_-_----_-__----_--------. I Medium gray to grayish black silty CLAY, damp, stiff 1 SANTIAGOFORMATION(Tsak. Light yellowish gray silty SANDSTONE, damp, medium dense, fine to medium grained KG INCORPORATED SOIL TEST Consolidation - .- - .- - - - - - ~- )ATE OBSERVED: 3-10-92 METHOD OF DRILLING: 8" Hollow Stem Auner LOGGED BY:&?dl GROUND ELEVATION:= LOCATION: See Mm ; 1 k ie e 9 !!I G &k Ew e ;” 02 k $ h zi g w” LOG OF BORING NO. B-l ag 3 fiz 8> Sheet 2 of 2 SOIL TEST F i du y 00) 5 & -J: q 3 i 85 am z= ‘O :I:,::,:]: 5(-J/~ 8 I.@; DeSCRIPTTON 12.5 121 SANTIAGO PEAK VOLCANICS &Dk 6” \ Light brown volcanic rock, very dense Total Depth 41’ 15- No water No caving Backfilled 3-10-92 ;o- j5- SO- 55- lO- 15- - .- ,,- - .- . . .- - _- - .- - .- )ATE OBSERVED: 3- 10-92 METHOD OF DRILLING: 8” Holloww Stem Awer .OGGED BY:= GROUND ELEVATION240 LOCATION: See Mat? LOG OF BORING NO. B-2 Sheet 1 of 1 DESCRIPTION @ 5’ fill becomes firm silty CLAY/elastic SILT, stiff Atterberg Limit, Direct @ 15’ fill becomes stiff yellowish gray silty SANDSTONE, damp, medium dense, fine grained IO-. ::..: : :: 31 m l5- 17.7 108 Total Depth 31’ No water No caving Backfilled 3-10-92 I”” I.“.: KG INCORPORATED rI”“Rm: _ - -- B- _~ .- ..~ .- - -- .- - IATE OBSERVED: 3-10-92 METHOD OF DRILLING: 8" Hollow Stem Auaer ~oGGEDBY:PAT GROUNDELEVATION:~~~' LOCATION: SeeMao DESCRIPTION SOIL TEST STP - No sample taken -______-_______-------------- Light olive brown silty CLAY, damp, stiff _-_-_-___-______-_-_--------- Olive black silty CLAY, moist, stiff ~-g,3294,0~-004,0 ICG INCORPORATED d - -. - - _- _- - - .- - - - - - )ATE OBSERVED: 3- 1 O-92 METHOD OF DRILLING: 8” Hollow Stem Auger ED I I I i : i j : :LEVATION:242’ LOCATION: See Mao LOG OF BORING NO. B-3 Sheet 2 of 2 OCSCRIPTION Total Depth 41’ No water No caving Backfilled 3-10-92 SOIL TEST ICG INCORPORATED I ,- - - -. - - - - - - - - - )ATE OBSERVED: 3-10-92 METHOD OF DRILLING: 8” Hollow Stem Auner .OGGED BY:- GROUND ELEVATION240 LOCATION: See MaD LOG OF BORING NO. B-4 Sheet 1 of 1 DEscmIPTIoN SOIL TEST Expansion, Sulfate, R-Value, Max. Density Moderate olive brown CLAYSTONE, damp, very stiff No water No caving Backfilled 3-10-92 15- SO- 35- m NO i_- ..-.: I - - -- ICG INCORPORATED Job No: 05-8829-001-00-00 APPENDIX C LABORATORY TESTING PROGRAM Log No: 2- 1145 - - - - 1. Sections C- 1 to C-8 2. Table C- 1 3. Table C-2 4. Table C-3 5. Table C-4 6. Figure C- 1 7. Figure C-2 8. Figure C-3 Laboratory Testing Procedures Expansion Test Results Sulfate Test Results R-value Test Results Optimum Moisture/Maximum Dry Density Determinations Atterberg Limits Test Result Consolidation Test Results Direct Shear Test Result rft&? c-2 c-3 c-3 c-3 c-3 - Job No: 05-8829-001-00-00 Log No: 2-1145 Page C-2 - .- - - - LABORATORY TESTING Selected representative samples of soils encountered were tested using test methods of the American Society for Testing and Materials, or other generally accepted standards. A brief description of the tests performed follows: C-l. c-2. c-3. c-4. c-5. C-6. C-l. C-8. aassification; Soils were classified visually according to the Unified Soil Classification System. Visual classification was supplemented by laboratory testing of selected samples and classification in accordance with ASTM D2487.. The soil classifications are shown on the Boring Logs. Exoans’o Test Expansion tests were performed using Uniform Building Code Test Method 29-2. ieyt result is provided on Table C-I. Sulfate Content; To access their potential for reactivity with concrete, a typical sample was tested for content of water-soluble sulfate minerals using CALTRANS method 417 (Part I). The results are listed on Table C-2. R-Value Tests; R-Value Testing was performed on a selected sample considered typical of pavement subgrade. Tests were performed using California Department of Transportation Method 301. The test result is presented on Table C-3. &Q&ure Densitv Relatieg; The maximum density and optimum moisture content of a soil samples was determined by ASTM D1557-78. The test result is presented in Table C-4. Atterbern LimitslThe liquid limit, plastic limit, and plasticity index of selected samples were determined in accordance with ASTM D 4318. The test result is shown on Figure C- 1. Consolidation Tes& Consolidation tests were performed on samples of the material encountered during field exploration to assess their compressibility under load. Testing was performed in accordance with ASTM D 2435-80. Result is shown on Figure C-2. Direct Shear Tests; Unconsolidated undrained and consolidated drained direct shear tests were performed in accordance with ASTM D3080. The utilized samples were undisturbed and tested in a saturated condition using normal loads of 1 ksf, 2 ksf and 4 ksf. The results of the tests are presented in the attached Figure C-3. - - - - Job No: 05-8829-001-00-00 Log No: 2-1145 Page C-3 TABLE C-l EXPANSION TEST RESULTS TABLE C-2 SULFATETESTRESULTS TABLE C-3 R-VALUE TEST RESULTS TABLE C-4 MOISTURE DENSITY RELATION - - - - -. _- .- - .- - - PLASTICITY CHART 60 SO is c 40 z CL ; 30 G F z 20 i 10 7 4 0 0 10 20 30 40 60 SO 70 80 90 100 LIQUID LIMIT (%I PLAS- UNIFIED TICITY ‘N^o”Sf$ LIQUIDITY SOIL INDEX &EVE INDEX CLASSI- w (X) (%I FICATION SYMBOL l S-2 10 ss 26 CM-n4 ATTERBERG LIMITS 06 NO.: IDATE: IFIQURE: -. ,.. .- - - - - .- .- NORMAL LOAD (PSF) 08 NO.: os-m2B-oo+oo-oo 1 CONSOLIDATION TEST RESULTS jF’Q”R&2 ICQ IncorFor~t~ - - - - _- .- -, .- - _~. ,- .- -_ . (I a ul ul 1000 / 0 OO 1000 2000 31 .I//- 1000 2000 31 ESCRIPTION “;;!a pFEEf)ETTH) “‘&5TpN &&E,$, EAK -+ S-2 10.0 0 4s ESIDUAL A SAMPLE DESCRIPTION SILTY CLAY/SILT (CH-YH) - UNDISTURBED w EAK - :ESlDUAL - ‘ESCRIPTION *olf;~Q f.FEP&!j co&;\oN F*dJ$i$ B-S S.0 0 33 I I - NORYAL LOAD (PSF) SAMPLE DESCRI SANDV CL*V ( UNDISTURW g SOOOL u) (1 f s % m / 0 OO 1000 2000 S( ‘ION .I )B NO.: NORMAL LOAD (PSF) 01-8629-001-00-00 1 DIRECT SHEAR TEST RESULTS IFiQURE: c-a ICQ Ineoroor~t~ Job No: 05-8828-001-00-00 Log No: 2-1145 - - - - - - - .- - - - - -- 1. Page 1 on 2. Figures D- 1 thru D- 9 APPENDIX D STANDARD GUIDELINES CONTENTS Standard Guidelines for Grading Project Typical Grading Details \ I I I \ \ 1 / I I I / \ \ I I I SURFACE OF FIRM EARTH MATERIAL UNWEATHERED BEDROCK OR APPROVED MATERIAL PER QEOTECHNICAL CONSULTANT HI2 OR 16’ MINIMUM OR AS REQUIRED FOR STABILITY PER aEOTECHNlCAL CONSULTANT FINISH CUT SLOPE NOTES. 1) DEPTH AND WIDTH OF LOWEST BENCH SUBJECT TO FIELD CHANGE BASED ON CONSULTANT’B INSPECTION. 2) BACKDRAIN MAY BE REQUIRED DEPENDING ON EXPOSED CONDITIONSISEEPAQE. FILL SLOPE ABOVE CUT SLOPE DETAIL ii >B NO.: DATE: FIGURE: D-l ,CG lncorporare BENCHING FILL OVER NATURAL SLOPE .-~ - - I FINISH COMPACTED FILL SLOPE- I SURFACE OF FIRM EARTH MATERIAL -,-I:~ ,::~:‘::~“,-“- ~~~~ e\~E~c~~~~ 2’ MINIMUM’ KEY DEPTH 16’ MINIMUM. OR AB REQUIRED FOR STABILITY PER QEOTECHNICAL CONSULTANT BENCHING FILL OVER CUT SLOPE I - - __ _- SURFACE OF FIRM EARTH MATERIAL- NATURAL TOPOQRAPHY FINISH COMPACTED FILL SLOPE 16’ MINIMUM. OR AS REOUIRED FOR STABILITY PER GEOTECHNICAL CONSULTANT LFINIBH CUT SLOPE I NOTES: 1) DEPTH AND WIDTH OF LOWEST BENCH SUBJECT TO FIELD CHANQE BASED ON CONSULTANT’S INSPECTION. 2) BACKDRAIN MAY BE REOUIRED DEPENDINQ ON EXPOSED CONDITIONSISEEPAQE. JOE NO.: BENCHING DETAILS DATE: IFIGURE: D-2 ~ ICG Incorporated ..~ _. ~~- ~- -. - .- OVEREXCAVATE AND REMOVE ALL TOPSOIL. FINISH CUT PAD OVEREXCAVATE 3’ AND FINISH COMPACTED FILL REPLACE WITH BLOPEREBTOREDTO COMPACTED FILL NATURALTOPOGRAPHY UNWEATHERED BEDROCK OR MATERIAL APPROVED PER QEOTECHNICAL CONBULTANT PROVIDE BACKDRAIN PER BACKDRAIN DETAIL. LOCATION OF BACKDRAIN AND OUTLETS PER GEOTECHNICAL CONSULTANT DURING GRADINQ 15’ MINIMUM. OR AS REQUIRED FOR STABlLlTY PER GEOTECHNICAL CONSULTANT. (DEPTH AND WIDTH OF LOWEST BENCH IS SUBJECT TO FIELD CHANQE BASED ON CONSULTANT’S INSPECTION. DAYLIGHT SHEAR KEY DETAIL OB NO.: IDATE: IFIGURE: _ _ .- - - _- - - .- _- .~- FINAL NATURAL SLOPE FINAL NATURAL SLOPE LIMITB OF FINAL EXCAVATION LIMITB OF FINAL EXCAVATION TOE OF SLOPE SHOWN ON QRADINQ PLAN TOE OF SLOPE SHOWN ON QRADINQ PLAN COMPETENT EARTH COMPETENT EARTH MATERIAL MATERIAL TYPICAL BENCH HEIGHT TYPICAL BENCH HEIGHT 16’ MINIMUM BASE KEY WIDTH “\ MINIMUM DOWNSLOPE KEY DEPTH PROVIDE BACKDRAIN AS REGUIRED PER RECOMMENDATIONS OF SOILS ENQINEER DURINQ QRADINQ WHERE NATURAL SLOPE GRADIENT 18 S:l OR LESS, BENCHING IS NOT NECESSARY. HOWEVER, FILL Is NOT 10 BE PLACED ON COMPRESSIBLE OR UNSUITABLE MATERIAL. 108 NO.: FILL SLOPE ABOVE NATURAL GROUND DETAIL DATE: FIQURE: b-4 IRVINE SOILS ENQINEERING. INC. .- - - - .- ~- ,- MINIMUM 4’ DIAMETER NON-PERFORATED OUTLET PIPES 100’MAXIMUM ON CENTER HORIZONTALLY. 30’ MAXIMUM ON CENTER VERTICALLY BLANKET FILL 3’ MINIMUM MINIMUM 4= DIAMETER NON- PERFORATED OUTLET PIPES 100’MAXlMUM ON CENTER HORIZONTALLY. 30’ MAXIMU ON CENTER VERTICALLY FINISH COMPACTED FILL SLOPE TYPICAL BENCHINQ AFTER REMOVING UNSUITABLE MATERIAL PIPE BACKDRAINS PER BACKDRAIN L-KEY DIMENSION PER QEOTECHNICAL CONSULTANT (QENERALLY 112 SLOPE HEIGHT OR 16’ ~i~iM~t.4) NOTES: 1) FOR TERRACED SLOPES, BACKDRAINS AND OUTLETS SHOULD BE PLANNED TO OUTLET ABOVE THE TERRACE DRAINS. 2) FILL BLANKET, BACKCUT, KEY WtoTH AND KEY DEPTH ARE SUBJECT TO FIELD CHANGE BASED ON CONSULTANT’S INSPECTIONS. 3) KEY HEEL SUBDRAIN AND BLANKET DRAIN MAY BE REQUIRED DEPENDING ON EXPOSED CONDITIONBISEEPAQE. 4) EACH SUBDRAIN SHOULD EXTEND THE ENTIRE LENQTH OF THAT PORTION OF BACKCUT EXPOSING BEDROCK. TYPICAL STABILIZATION FILL DETAIL JOB NO.: DATE: IFIGURE: D -5 ICG Incorporate - - - - - 12’ MINIMUM BEDDINQ BACK DETAIL A-A TEMPORARY FILL LEVEL SELECT :FILL -4’ MINIMUM DIAMETER NON- PERFORATED OUTLET PIPE. MINIMUM 2% GRADIENT ’ kl2. MIN.+ *FILTER MATERIAL SHALL BE CLASS 2 PERMEABLE MATERIAL PER STATE OF CALIFORNIA STANDARD ++APPROVED PIPE TYPE: SPECIFICATIONS. OR TO MEET FOLLOWING SPECIFICATION. OR APPROVED EQUIVALENT: SCHEDULE 40 POLYVINYL CHLORIDE (P.V.C.) OR APPROVED EPUIVALENT. MINIMUM CRUSH STRENGTH 1000 PSI. SIEVE PERCENTAQE PASSING 3% 100 3/w 00-100 NO.4 EE: gc:y 6-15 NO:200 i-i TYPICAL BACKDRAIN DETAIL JOB NO.: DATE: FIGURE: b ICQ Incorporated - - - - - - .- - - - - - - - - - - TYPICAL SURFACE OF FIRM EARTH MATERIAL -4-J 0 \ INCLINE TOWARD DRAIN SEE DETAIL BELOW DETAIL ----A----- MINIMUM 4. DIAMETER APPROVED PERFORATED PIPE (PERFORATIONS MINIMUM 3 FT3PER LINEAR FOOT OF APPROVED FILTER MATERIAL 6’ FILTER MATERIAL EEDOINQ FILTER MATERIAL TO MEET FOLLOWINQ SPECIFICATION OR APPROVED EQUAL: APPROVED PIPE TO SE SCHEDULE 40 POLY-VINYL-CHLORIDE (P.V.C.) OR APPROVED EQUAL. MINIMUM CRUSH STRENQTH 1000 ~61 SIEVE SIZE 1’ 314. 315’ NO.4 NO.30 NO.60 NO.200 PERCENTAGE 100 80-100 40-100 25-40 5-15 o-7 o-3 PIPE DIAMETER TO MEET THE FOLLOWINQ CRITERIA. SUBJECT TO FIELD REVIEW BASED ON ACTUAL GEOTECHNICAL CONDITIONS ENCOUNTERED DURINQ GRADING LENGTH OF RUN PIPE DIAMETER UPPER 600’ 4’ NEXT 1000’ 6’ > 1500’ 8’ TYPICAL CANYON SUBDRAIN DETAIL JOB NO.: IDATE: IFIGURE: ~ ICG Incoreoratc ~~_ -. - - - .- MINIMUM 4’ DIAMETER NON-PERFORATED OUTLET PIPES 100’MAXIMUM ON CENTER HORIZONTALLY. BLANKET FILL 3’ MINIMUM 30’ MAXIMUM ON CENTER VERTICALLY .\ .f$@ c 3’ MINIMUM KEY DEPTH KEY DIMENSION PER QEOTECHNICAL CONSULTANT NOTES: 1) WIDTH AND DEPTH OF BUTTRESS KEY AS SPECIFIED IN QEOTECHNICAL REPORT. 2) KEY HEEL SUBDRAIN AND BLANKET DRAIN MAY BE REQUIRED DEPENDINQ ON EXPOSED CONDlTlONBfSEEPAQE. 31 EACH SUSDRAIN SHOULD EXTEND THE ENTIRE LENGTH OF THAT PORTION OF BACKCUT EXPOSING BEDROCK. 4) FILL BLANKET, BACKCUT. KEY DEPTH AND WIDTH ARE SUBJECT TO FIELD CHANQE BASED ON CONSULTANT’S INSPECTION. 6) FOR TERRACED SLOPES. BACKDRAINS AND OUTLETS SHOULD BE PLANNED TO OUTLET ABOVE THE TERRACE DRAINS. JOB NO.: TYPICAL BUTTRESS FILL DETAIL DATE: IFIQURE: b- 8 ICQ Incorporal - - - - - - - CUT/FILL LOT (TRANSITION) COMPACTED FILL OVEREXCAVATE AND REQRADE /’ UNWEATHEREv ~cvnvtin I. TOPSOIL. COLLUVIUM AND WEATHERED BEDROCK REMOVED BY BENCHINQ , TRANSITION LOT DETAIL JOB NO.: IDATE: -- IFIOURE: h -9 I “-I ICG Incorpora1.d