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Home My WebLink AboutSUP 98-03D; VIASAT BLDG 1; GEOTECHNICAL INVESTIGATION; 2008-01-23f\LE COP1 GEOTECHNICAL INVESTIGATION PROPOSED BUSINESS PARK Bressi Ranch Lots 10-13 Planning Area 3 Carlsbad, California for Levine Investments St,tP qg, 0,1> ~~ SOUTHERN '1lliF' -CALIFORNIA -- ", SoCalGeo January 23, 2008 Levine Investments 1702 East Highlands Avenue, Number 310 Phoenix, Arizona 85016 Attention: Mr. Andrew Cohn Project No.: 076227-1 Subject: Geotechnical Investigation Gentlemen: Proposed Commercial/Industrial Development Bressi Ranch Lots 10-13 Planning Area 3 NEC of Gateway Road and El Camino Real Carlsbad, California " ~$ GEO!~~~~!}; Ih accordance with your request, we have conducted a geotechnical investigation at the subject site. We are pleased to present this report summarizing the conclusions and recommendations developed from our investigation. We sincerely appreciate the opportunity to be of service on this project. We look forward to providing additional consulting services during the course of the project. If we may be of further assistance in any manner, please contact our office. Respectfully Submitted, SOUTHERN CALIFORNIA \L-¼ R bert G. Trazo, M.Sc., GE S ni 5) Addressee 22885 East Savi Ranch Parkway,.. Suite E,.. Yorba Linda, CA 92887-4624 voice: (714) 685-1115,.. fax: (714) 685-1118,.. www.socalgeo.com TABLE OF CONTENTS 1.0 EXECUTIVE SUMMARY 2.0 SCOPE OF SERVICES 3.0 SITE AND PROJECT DESCRIPTION 3.1 Site Description 3.2 Proposed Development 3.3 Previous Studies . 4.0 SUBSURFACE EXPLORATION 4.1 Scope of Exploration/SamplingNethods 4.2 Geotechnical Conditions · 4.3 Geologic Conditions 5.0 LABORATORY TESTING 6.0 CONCLUSIONS AND RECOMMENDATIONS 6.1 Seismic Design Considerations 6.2 ·Geotechnical Design Considerations 6.3 Site Grading Recommendations 6.4 Construction Considerations 6.5 Foundation Design and Construction 6.6 Floor Slab Design and Construction 6.7 Retaining Wall Design Recommendations 6.8 Pavement Design Parameters 7.0 GENERAL COMMENTS . APPENDICES A Plate 1: Site Location Map Plate 2: Boring Location Plan B Boring Logs C Laboratory Test Results D Grading Guide Specifications· E Sei.smic Design Parameters . . SOUTHERK CALIFORNIA -. GEOTECHNICAL 1 3 4 4 4 4 9 9 9 10 11 13 13 15 17 19 21 22 23 25 28 Bressi Ranch, Lots 10-13 -Carlsbad, CA Project No. 07G227·1 '( 1.0 EXECUTIVE SUMMARY Presented below is a brief summary of the conclusions and recommendations of this investigation. Since this summary is not all inclusive, it should be read in complete context with the entire report. Site Preparation • Initial site preparation should include stripping of any surficial vegetation and/or significant topsoil. Ba~ed on conditions encountered at the ti'me of the. subsurface exploration, stripping of moderate. grass and weed growth Is expected to be necessary. • The site is ,underlain by recently placed compacted fill sous and sandstone, siltstone and daystone bedrock. The fill soils extend to depths of up to 8± feet within the footprints of the proposed buildings and were placed under the purview of a geotechnical engineer. The existing fill soils and bedrock possess moderate to high strengths and medium expansive potentials. • The compaction report prepared by Leighton and Associates .indicates that the existing fill soils were placed as compacted structural fill. Leightori indicates that the existing fill soils are suitable for support of the proposed development provided that the cut/fill transitions are mitigated during precise grading. • In order to provide for a new layer of structural fill that will help mitigate the variable support conditions due to the potentiar cut/fill transitions, It is recommended that remedial grading be performed within the proposed building pad areas. • Both building pad areas are underlain by shallow bedrock and shoultj be overexcavated to a depth of at least 3 feet below existing grade and to a depth of at least 3 feet below proposed pad grade. The depth of overexcavatlon should be sufficient to provide at least 3 feet of new structural fill beneath the be1;1ring grade of all foundations. • In the remaining portions of the site, overexcavation should extend to a depth adequate to remove all surficial, weathered soils. • Following completion of the recommended overexcavation, exposed soils should be evaluated by the geotechriical engineer. After the subgrade soils have been approved by the geot~chnical engineer, the resulting soils may be repl'aced as compacted structural fill. • A precise grading plan review is recommended subsequent to preparation of the plan in order to confirm the recommendations contained herein. Building Foundations • · Shallow foundations, supported in newly plated compacted fill. • 2,500 .psf maximum allowable soil bearing pressure. • Minimum longitudinal steel reinforcement Within strip footings: Four ( 4) No. 5 rebars (2 top and 2 bottom), due to the medium expansive potential of the near surface soils. Building Floor Slabs • Slab-on-'Grctde~ at least 5 inches thick. • Minimum slab reinforcement: No. 3 bars at 18-inches on-center, in both directions. Bressi Ranch, Lots 10-13 -Carlsbad, CA Project No, 07G227-1 Page 1 Pavements .. . ASPHALT PAVEMENTS . . . Thickness _(inches) Materials Auto Parking Auto Drive Light Truck Moderate (TI= 4.5) Lanes Traffic Truck Traffic m-s.s) m-6.m (TI -7.0) Asphalt Concrete 4 4 4 4 Aggregate Base 5 8 10 13 .. _ Compacted Subgrade (90% minimum compaction) 12 i2 12 12 .. . . PORTLAND CEMENT CONCRETE PAVEMENTS .. Materl~ls Automobile Parking · (TI= 4.5) PCC 5 -Compacted Subgrade 12 (95% minimum comoaction) ~ SOUTHERN ~ I CALiFORNiA ,. ______ GEOTECHNJCAL Thickness (inches) Drive Lanes (TI = Moderate Truck 5.~) and Light Truck Traffic Traffic (tr-6,0) (TI= 7.0) 5½ 7 12 12 Bressi Ranch, Lots 10-13 -Carlsbad, CA Project No. 07G227-1 Page 2 2.0 SCOPE OF SERVICES The scope of services performed for this project was in accordance with our Proposal No. 07P379, dated November 30, 2007. The scope of services included review of previous reports, a visual site reconnaissance, subsurface exploration, field and laboratory testing, and geotechnical engineering analysis to provide criteria for preparing design of the building foundations, building floor slabs, and parking lot pavements along With site preparation recommendations and construction considerations for the. proposed development. The evaluation of environmental aspects of this site was beyond the scope of services for this geotechnical investigation. ..alP SOUTHERN ,,..,. 1 . CALIF9RNIA ~-_ G.E.Qt~.~HN.~i\i Bressi Ranch, Lots 10-13 • Carlsbad, CA Project No. 07G227·1 Page 3 3.0 SITE AND PROJECT DESCRIPTION 3.1 Site Description The subject site is located within the recently mass graded Bressi Ranch Industrial Park which is located southeast of the intersection of Palomar Airport Road and El Camino Real In the city of Carlsbad, California. The specific site is a portion of Planning Area 3, Lots 10 though 13, and is located northeast .of the Intersection of Gateway Road and El Camino Real. The general location of the sit~ ls illustrated on the Site Location Map, included as Plate 1 in Appendix A of this report. The subject site is an irregularly-shaped· parcel, approximately a± acres in size. Graded slopes ranging in height from 5 to 7± feet border the site to the north and east. Five (5) desilting basins were located throughout the site. The desilting basins were approximately 6 to 8± feet deep. At the time of the subsurface exploration, ground surface cover consisted of exposed soil with moderate grass and weed growth. Preliminary topographic Information was obtained from a plan prepared by Smith Consulting Architects (SCA). The site plan Indicates that site grades within Lots 10 through 13 range from El. 325± feet msl at the northeastern property corner to El. 295± feet msl at the southwestern property corner. 3.2 Prop'?sed Deyelopment Preliminary information regarding the proposed development was obtained from the site plan prepared by Smith Consulting Architects. These plans have been provided to our office by the client. This plan indicates that the new development will consist of two (2) separate two-or three-story buildings. The proposed building footprints will be 21,700± ft2 and 25,600± ft2 • Detailed structural information is not currently available. It Is, however, assumed that the buildings will be of concrete tilt-up construction, typically supported on conventional shallow foundation systems and concrete slabs on grade. Based on the assumed construction, maximum column and wall loads are expected to be on the order of 60 to 80 kips and 3 to 5 kips per linear foot, respectively. 3.3 Previous Studies As part of our investigation of the overall site, including Planning Areas PA-1 through PA-5, we were provided with several geotechnical reports. The geotechnical reports provided to us consist of preliminary and supplemental geotechnical Investigations, a summary report of mass grading, and as graded reports of mass grading. The subject site has been recently rough graded to Its ·-SOUTHERN ' ' CALIFORNIA T GJQ.T~_Q:U~!~~L Bressi Ranch, Lots 10·13 -Carlsbad, CA Project No. 07G227-1 Page4 ) ' current configuration. under the purview of Leighton and Associates, Inc. The reports which are applicable to the entire site, lncluc:ling all of the Planning Areas, are summarized below: • Geotechnlcal Investigation, Proposed Business Park, Bressi Ranch Lots 10 -13. Planning Area 3, Carlsbad, California; prepared for Ascent Biltmore, LLC by Southern California Geotechnical, Inc., dated December 19, 2006, Project No. 06G252-1. This report presents the results of our previous geotechnical investigation of the subject site. The work documented by this report occurred during the period of December 1, 2006 through 'December 19, 2006. This report states thi:lt fifteen (iS) borings were drilled within the site to a depth of 19½± feet. The maximum depth of the borings was limited to less than 20 feet due to permit restrictions imposed by the San Diego County Department of Environmental Health (DEH). The borings identified engineering fill soils extending to depths of 1 ½ to 12½± feet below e~isting grade. Below the fill soils, Santiago Formation bedrock materials were observed to the maximum depth explored of 19½± feet below ground surface. Groundwater was reportedly not encountered in any of the borings. The report identified corrective grading removals of shallow bedrock for the twelve building pad areas on the order of 3 feet below existing grade and to a depth of 3 feet below proposed pad grade. In addition, the depth of overexcavation was recommended to provide at least 3 feet of new structural fill beneath the bearing grade of all foundations for the selected buildings. • Geotechnical Investigation, Proposed Business Park, Bressi Ranch Lots 10 -13. Planning Area 3, Carlsbad, California; prepared for· St. Croix Capital by Southern California Geotechnical, Inc., dated November 16, 2005, Project No. 05G273-1. This report presents the results of our previous geotechnical investigation of the subject site. The work documented by this report occurred during the period of October 31, 2005 through November 16, 2005. This report states that eight (8) borings were drilled within the site to depths rclnging from 10 to 19½± feet. The maximum depth of the borings was limited to less than 20 feet due to permit restrictions imposed by the San Diego County Department of En.virontnental Health (DEH). The borings identified engineering fill soils extending to depths of 2 to 2½* feet below existing grade. Below the fill soils, Santiago Formation bedrock materials were observed to the maximum depth explored of 19½± feet below ground surface. Groundwater was reportedly not encoLJntered in any of the borings. The report identified corrective grading removals of shallow bedrock for the two building pad areas on the order of 3 feet below existing grade and to a depth of 3 feet below proposed pad grade. In addition, the depth of overexcavation was recommended to provide at least 3 feet of new structural fill beneath the bearing grade of all foundations for the ~elected buildings. • Geotechnical Investigation, Bressi Ranch Corporate Center, Planning Areas 1 through 5, SEC of Palomar Airport Road and El Camino Real, Carlsbad, California; prepared for Sares Regis Group by Southern California. Geotechnical, Inc., dated May 3, 2004, Project No. 03G259-2. This report presents the results of our geotechnical investigation of Planning Areas 1 through 5 subsequent to the mass grading. Subsurface exploration performed as part of this geotechnical -SOUTHERN ' ' • CALIFORNIA T. GEOTECHNICAL Bressi Ranch, Lots 10-13 -Carlsbad, CA Project No. 07G227-1 Page 5 investigation included twenty (20) borings advanced to depths of 5 to 19½± feet below currently existing site grades. The maximum depth of the borings was limited to less than 20 feet due to permit restrictions imposed by the San Diego County Department of Environmental Health (DEH). Based on the subsurface conditions, the site is underlain by recently placed compacted fill soils and sandstone and claystone bedrock. The fill soils extend to depths of up to 90± feet and were plijced under the purview. of a geotechnlcal engineer. The existing· fill soils and bedrock possesses relatively high strengths, and highly variable· expansive potentials. Based on the variable expansive potentials and differing strengths of the engineered fill and bedrock, and in order to provide for a new layer of structural fill that will help mitigate the potential cut/fill transitions, it was recommended that remedial grading be performed within the proposed building pad areas. The building pad areas were-recommended to be overexcavated to a depth of at least 5 feet below existing grade and to a depth of at least 4 feet below proposed pad grade. The depth of overexcavation should be sufficleht to provide at least 3 feet of new structural fill beneath the bearing grade of all foundations. • Supplemental . Geotechnical Investigation for Mass Grading. ·Bressi Ranch. Carlsbad. California, prepared for Lennar Homes by Leighton and Associates, Inc., dated March 14, 2001, Project No. 97i009-005. This report presents th_e results Of a supplemental geotechnical investigation to update their earlier prelimlnary·.geotechnical report prepared in 1997. Subsurface exploration performed as part of the supplemental geotechnical investigation included eight (8) large diameter borings and fifty-six (56) exploratory trenches. Logs of these supplemental borings and trenches as well as previous work by Leighton and others is included in the report and summarized on the Geotechnic.al Map Included therein. Based on the presented Information, the subject site is primarily underlain by sandstone bedrock. The .bedrock· is indicated to c;onsist of the Tertiary age Santiago formation, which is described as massively bedded sandstone with some zones of claystone and siltstone. Some minor areas of shallow undocumented fill, terrace deposits, and alluvial/colluvial soils were also mapped within the poundarles of the subject site. Although the majority of the mapped, larger ancient landslides are -located outside the boundaries of the subject site, two (2) small ancient landslides were mapped on the subject site, east of PA-1 and PA"'2. Due to their small scale, they were recommended to be removed in their entirety and replaced as compacted fill. Remedial grading ,recommendations contained in this report indicate that all undocumented fill and alluvial/colluvial soils should be completely removed to competent material. • Supplemental Geotechnical Landslide Investigation,· Planning Areas PA-1. PA~2, and PA- 10 through PA-12, Bressi Ranch. Carlsbad. California, prepared for Lennar Communities by Leighton ahd Associates, Inc., dated February 12, 2003, Project No. 971009-007. Bressi Ranch, Lots 10-13 -Carlsbad, CA Project No. 07G227-1 Page 6 This report presents the results of a supplemental _geotechnical landslide investigation for specific portions of the site. Subsurface exploration performed. as part of the supplemental geotechnical lgnd~lide Investigation included nine (9) large diameter borings and five (5) exploratory trenches in the areas of the previously mapped ancJent landslides. Logs of these additional borings and trenches as well as revised cross sections are included in the report. The area of the subject site addressed by this report includes the eastern portion of planning areas PA-1 and PA-2 where several nested ancient landslides Were mapped. Cross Sections E-E' and P-P' depict the mapped geologic conditions and the recommended remedial grading, which consisted ef complete removal of the landslides and replacement as engineered fill. This report restates the previous remedial grading recommendations-and provides slope stability calculations to justify the proposed grading configurations. • Geotechnical Recommendations Concerning 95 .Percent Relative Compaction of Fill Deeper than 40 Feet, Bressi Ranch, Carlsbad; California, prepared for Lennar Communities by Leighton and Associates, Inc., dated February 13, 2003, Project No. 9]l009-007. This report addresses the settlement potential of deep fill areas arid provides recommendations to reduce the time period for the majority of the settlement to occur. In several areas of the overallpr,oject, fills up to 40 to 50± feet In thickness were planned to achieve the design grades. Deep fill areas on: the subject site are located in the eastl:!rn portion of PA-2, and two small areas within PA.,3 and PA"-5. The report recommends that all structural fills below a depth of 40 feet from fini$h grade be compacted to at least 95 percent of the ASTM D-1557 maximum dry density, and estimates that the time period for the majority of the settlement to occur will be reduced from 6 to 12 months to 3 to 8+ months. Near surface settlement monuments were recommended to be installed immediately after rough grading, with survey intervals of once a week for the first month, then twice a month for 3 months, and then mpnthly to determine completion primary settlement of deep fills. The recommended locations of the near surface settlement monuments are indicated to be contained on an index map within this report, however, the copy provided to us does not contain this plan. • Summary of the As-Graded Geotechnical Conditions and Partial Completion of Rough and Fine Grading, Planning. Areas· PA-1 Through PA-5, Bressi · Ranch, Carlsbad, California, prepared for Lennar Communities by Leighton and Associates, Inc., dated January 20, 2004, Project No. 971009-014. This summary report indicates that grading of Planning Areas PA-1 through PA-3 is essentially complete, and th~t grading is ongoing in Planning Areas PA-4 and .PA-5. Grading operations were r~portedly performed in general accordance with. the recommendations presented in Leighton's previQus geotethnlcal reports. Geotechnical issues presented in this summary report which were not discussed in the previous reports include the presence of inactive faults within PA-4 and PA.:.5, perched groundwater within the overexcavated tributary canyons on the east side of PA-1 and PA-:2, oversize materials within the engineered fills, high to very high expansive soils at or near finish grade, and some severe sulfate concentrations which would require the use of spe~ialized concrete mix. designs. ~ SOUTHERN ' . ' CALIFORNIA T GEOTECH_~J~AL. Bressi Ranch, Lots 10-13 -Carlsbad, CA Project No. 07G227-1 Page 7 • As Graded Report of Mass Grading, Planning Areas PA-1, PA-2, and PA-3, Metropolitan Street, and a Portion of Town Garden Road; Gateway Road, and Alicante Roacl. Carlsbad Tract No. 00 ... 061 Bressi Ranch, Carlsbad, California, prepared for Lennar Communities by Leighton arid Associates, Inc., dated April 15, 2004, Project No. 971009-014 This report documents the mass grading of Planning Ar~as PA-l, PA-2, and PA-3 as well as a portion of the interior streets. Most of the information contained In this report was presented In the January 20, 2004 summary report. The conclusions and recommendations are also similar to the previous report. With respect to the deep fills on this portion of the site, Leighton concluded that most of the anticipated settlement is complete, but the seven settlement monuments should . be c:ontinued to be monitored. Soluble sulfate test results range from negligible to severe, and expansion index test results range from low (EI = 46) to very high (EI = 163). Preliminary pavement sections are presented and are based on assumed R-value of 12. Maximum cuts and fills within Planning Areas PA-1, PA-2, and PA-3 are documented as 25 and 90 feet, respectively. FIii soils below a depth of 40 feet were compacted to at least 95% of ASTM 1557 maximum dry density. • Addendum to As-Graded Reports of Mass Grading Concerning the Completion of Settlement Monitoring, Planlilng .Areas PA-1 through PA..:5, Bressi Ranch, Carlsbad, California, prepared for Lennar Communities by Leighton and Associates, Inc., dated October 11, 2004, Project No. 971009-014 · This report presents the data collected from the settlement monitodng program for the deep fill (greater than 40 feet) areas of the entire site. The settlement monitoring data was collected over a period of 5 to 6 months. Based on the collecteq data, Leighton concludes that the primary settlement of tbe fill soils is essentially complete, and that construction of improvements within Planning Areas PA-1 through PA-5 may begin. Secondary consolidation settlement of deep fills Is estimated to be less than 1 to 3 inches depending on the depth of fill. Differential settlements are estimated to be on the order of ½ inch in 25 feet. Bressi Ranch, Lots 10·13 -Carlsbad, CA Project No. 07G227-1 Pages 4.0 SUBSURFACE EXPLORATION 4.1 Scope of Exploration/Sampling Methods The subsurface exploration conducted for this project consisted of eight (8) borings advanced to depths of 19½± feet below currently existing site grades. The maximum depth of our borings was limited· to less than 20 feet due to permit restrictions imposed by the San Diego County Department of Environmental Health (DEH). All of the borings were logged during excavation by a member of our staff. Representative bulk and in-situ soil samples were taken during drilling. Relatively undisturbed in-situ samples were taken with a split barrel "California Sampler" containing a series of one inch long, 2.416± inch djijmeter brass rings. This sampling method is described in ASTM Test Method D-3550. In-situ samples were also taken using a 1.4± inch inside diameter split spoon sampler, ih general accordance with ASTM D-1586. Both of these samplers are driven into the ground with successive blows of a 140-pound weight falling 30 inches. The blow counts obtained. during driving are recorded for further analysis .. Bulk samples were taken at periodic locations in the trenches. The bulk samples were collected in plastic bags to retain their original moisture content. The relatively undisturbed ring samples were placed in molded plastic sleeves that were then sealed and transported to our laboratory. The approximate locations of the borings are indicated on the Boring Location Plan, included as Plate 2 of this report. The Boring Logs, which illustrate the conditions encountered at the boring locations, as well as some of the results of the laboratory testing, are included in Appendix B. 4.2 Geotechnical Conditions . Presented· below is a generalized summary of the subsurface conditions encountered at the boring locations. More detailed descriptions of the conditions encountered are illustrated on the Boring Logs, included in Appendix B. Artificial FIii Artificial fill soils were encountered ,at the ground surface c,lt many of the boring locations. These fill soils extend to depths of up to 8± feet beiow existing grade. As previously discussed, the fill soils within other areas of PA-3 are documented to have maximum depths of 40 to 50± feet. The fill soils encountered in the barings generally consist ·of medium dense fine sands and clayey fine sands. The fill soils possess moderately high strengths, moisture contents near or above optimum and based on their color mottling and composition, appeared to be well mixed. ' SOUTHERN ' ' CALiFORNIA T GEOTECHNICAL Bressi Ranch, Lots 10·13 -Carlsbad, CA Project No. 07G227-1 Page9 ·r Bedrock Bedrock was encountered at or near ground surface or beneath the fill soils at all of the boring locations. The l;>edrock encountered at this site consists of Tertiary age Santiago formation, which Is comprised of dense to very dense sandstone with some zones of claystone and siltstone. Bedding-within the Santiago formation oh site is generally massive with no significant planes of weakness or discontinuities. The sandstone unit is typically light gray in color, contains moderate iron oxide staining, and is comprised of weakly cemented silty fine sand. The siltstone unit is typically light gray to gray in color, contains moderate iron oxide staining, and is comprised of fine sandy silt. The claystone unit is typfcally dqrk gray to gray green in color, contains some shell fragments, gypsum veins, and is comprised of silts and clays. Groundwater Based on the water level measurements, and the moisture contents of the recovered soil samples, the static groundwater table is consider:eq to have existed at a depth in excess of 20± feet at the time of the subsurface exploration. Further, base<;! on the conditions documented in the mass grading report by Leighton, no groundwater was encountered during grading. Therefore, groundwater is expected to be at depths greater than the extent of the fill solls, which are 40 to 50± feet thick within PA-3. 4.3 Geologic Conditions Geologic research indicates that the site is, underlain by sandstone mapped as the Santiago Formation (Map Symbol Tsa) with nearly horizontal bedding attitudes. The primary available reference applicable to the subject site is DMG Open-File Report 96-02, Geologic Map of the Northwestern Part of San Diego_ County, California, by California Division of Mines and Geology, 199G. Based on the materials encountered in the exploratory borings, It Is our opinion the site is underlain by sandstone, siltstone and claystone oeqrock consisting of the Santiago formation · (Map Symbol Tsa). The bedrock encountered in the exploratory borings and observed at the ground surface is generally massively bedded and the structure is comprised of nearly horizontal bedding with some moderately developed joints in the upper, less weathered portions of the .bedrock. - Bressi Ranch, Lots 10-13 -carfsbad, CA Project No. 07G227·1 Page 10 'r 5.0 LABORATORY TESTING The soil samples recovered from the subsurface exploration were returned to our laboratory for further testing to determine selected physical and engineering properties of the soils. The tests are briefly discussed below. It sho1,.1ld be noted that the test results are specific to the actual samples tested, and variations could be expected at other locations and depths. Classification All recovered soil samples were classified using the Unified Soil Classification System (USCS), in accordance with ASTM' D-2488. Field identifications were then supplemented with additional visual classifications and/or by laboratory testing. The uses classifications are shown on the Boring Logs and are periodically referenced throughout this r;eport. In-_situ Density and Moisture Content The density has been determined for selected relatively undisturbed ring samples. These densities were determined In general accordance with the method presented in ASTM P-2937. The results are recorded as dry unit weight 'in pounds per cubic foot. The moisture contents are determined in accordance with ASTM D-2216, and are expressed as a percentage of the dry weight. These test results are presented on the Boring Logs. Consolidation Selected soil samples have been test~d to determine their consolidation potential, in accordance with ASTM D-2435. The testing apparatus is designed to accept either natural or remolded samples in a one-inch high ring, approximately 2.416 Inches in diameter. Each sample is then loaded Incrementally In a geometric progression and the resulting deflection Is recorded at selected time intervals. Porous stones are in contact with the top and bottom of the sample to permit the addition or release of pore water. The samples are typically inundated with water at an intermediate load to determine their potential for collapse or heave. The results of the consolidation testing are plotted on Plates C-1 through C-8 in Appendix C of this report. Expansion Index The expansion potential of the on-site soils was determined in general accordance with Uniform Building Code (UBC) Standard 18-2. The testing apparatus is designed to accept a 4-inch diameter, 1-in high, remolded sample. The sample is initially remolded to 50 ± 1 percent saturation and then loaded with a surcharge equivalent to 144 pounds per square foot. The sample is then inundated with water, and allowed to swell against the surcharge. The resultant swell or consolidation is recorded after a 2+hour period. The results of the EI testing are as follows: Bressi Ranch, Lots 10-13 -carlsbad, CA Project No. 07G227-1 Page 11 6.0 CONCLUSIONS AND RECOMMENDATIONS Based on the results of our review, field exploration, laboratory testing and geotechnical analysis, the proposed development is considered feasible from a geotechnical standpoint. The recommendations contained in this report should be taken into the design, construction, and grading considerations. The recommendations are contingent upon all grading and fo1,1ndation construction activities being monitored by the geotechnlcal engineer of record. The Grading Guide Specifications,. included as Appendix D, should be considered part of this report, and should be incorporated into the project $pecifications. fhe contractor and/or owner of the development should :bring to the attention of the geotechnical engineer any conditions that differ from those stated in this report, or which may be detrimental for the development. Following completion of the recommended grading and fo1,Jndation construction procedures, the subject site is considered suitable for its intended use. 6.1 Seismic Design considerations The subject site is located in an area which is subject to strong ground motions due to earthquakes. The completion of a site specific seismic hazards analysis is beyond the scope of services for this geotechnical investigation. However, it should be noted that numerous faults capabre of producing significant ground motions are located near the. subject site. Due to economic consideratfons, it is not generally considered reasonable to design a structure that is not susceptible to earthquake damage. Therefore, significant damage to structures may be unavoidable during large earthquakes. The proposed structures should, however, be designed to resist structural collapse and thereby provide reasonable protection from serious injury, catastrophic property damage and loss of life. Faulting and Seismicity Research of available maps indicates that the subject site is not lo<;:ated within an Alquist-Priolo Earthquake Fault Zone. Therefore, the possibility of significant fault r\.lpture on the site is considered to be low. Seismic Design. Parameters Based on standards in place at the time of this report, the proposed development must be designed in accordance with the requirements of the latest edition of the 2007 California Building Code (CBC), which -is based on the 2006 International Buflding Code (IBC). The IBC provides pro<;:edures for. earthquake resistant structural design that Include considerations for on-site soil conditions, occupancy, and the configuration of the structure including the structural system and height The seismic design parameters presented below are based on the; soil profile, and the proximity of ,known faults with respect to the subject site. ~ SOUTHERN ...,.,,. 1 CALIFORNIA ,, ____ .§~Q·rn~ijNJ.~AL Bressi Ranch, Lots 10-13 -Carlsbad, CA Project No. 07G227-1 Page 13 The 2006 IBC Seismic Design Parameters have been generated using Earthquake Ground Motion Parameters, a software application developed by the United States Geological Survey. This software application, available at the USGS web site calculates seismic design parameters in accordance with the 2006 IBC, utilizing a database of deterministic site accelerations at 0.01 degree intervals. The table below is a compilation of the data provided by the USGS application. A cQpy of the output generated from this program is included in Appendix -E of this report. A copy of the Design Response Spectrum, as generated by the USGS application is also included in Appendix E .. Based on this output, the following parameters may be utilized for the subject site: 2006 IBC SEISMIC DESIGN PAMMETERS Parameter Value . M~pped Spectral Acceleration at 0.2 sec Period Ss 1.794 . Mapped Spectral Acceleration aU.0 sec Period 51 0.667 Site Class ---D . Short-Period Site Coefficient at 0.2 sec Period Fa 1.0 l,.ong"'Period_Site Coefficient at 1.0 sec Period Fv 1.5 Site Modified Spectral Accel_eration at 0.2 sec Period SMs 1.794 Site Modified Spectral Acceleration at 1.0 sec Period SM1 1.0 Design Spectral Acceleration at 0.2 sec Period Sps 1.196 Design Spectral Acceleration at 1.0 sec Period So1 0,667 Liquefaction Liquefaction is the loss of strength in generally cohesionless, saturated soils when the pore- water pressure induced in the soil by a seismic event becomes equal to or exceeds the ov.erburqen pressure. The .primary factors which influence the potential for liquefaction include groundwater table elevation, Soil type and grain size 'Characteristics, relative density of the soil, initial confining pressure, and intensity .and duration of ground shaking. The depth within which the occurrence of liquefaction may impact surface improvements is generally identified as the upper 50 feet below the existing ground surface. Liquefaction potential is greater in saturated, loose, poorly graded fine sands with a mean (dso) grain size in the range of 0.075 to 0.2 mm (Seed and Idriss, 1971). Clayey (cohesive) soils or soils which possess clay particles (d<0.00Smm) in excess of 20 percent (Seed and Idriss, 1982) are generally not considered to be susceptible to liquefaction, nor are those soils which are above the historic static groundwater table. The subsurface conditions encountered at the subject site are not conducive to liquefaction. These conditions consist of compacted fill soils underlain by high strength sandstone and claystone bedrock, which is not susceptible to earthquake-induced liquefaction. Based on the subsurface conditions, liquefaction is not considered to be a significant design concern for this project. SOUTHERN ' . ' CALiFORNiA T. GEOTECHNICAL Bressi Ranch, Lots 10·13 • Carlsbad, CA Project No. 07G227-1 Page 14 ( 6.2 Geotechnical Design considerations General The subject, site is underlain by fill soils and by sandstone and occasional siltstone and claystone bedrock. The fill soils, extending to maximum depths of up to 8± within the subject site generally consist of moderate strength sands, silty sands and clayey sands. Laboratory testing indicates that these materials possess generally favorable consolidation and collapse characteristics. However, several cut/fill transitions between the fill and bedrock were created by the mass grading procedures. More importantly, the proposed grading to establish the new finished floor elevations Is expected to· result in the formation of additional cut/fill transitions. The resultant subsurface profile is expected to provide variable support characteristics for the foundations of the proposed structures. Based on these considerations, it Is recommended that remedial .grading be performed within the new building areas in order to provide a subgrade suitable for support of the foundations and floor slabs of the new structures. The primary geotechnical design consideration that will impact the proposed development is the fact that the proposed grading will create cut/fill transitions within some of the proposed building areas. These considerations are discussed in detail in the following sections of this report. Grading and Foundation Plan Review The conclusions and recommendations presented in this report are based on the preliminary plans provided to our office. No grading plans were availabie at the time of this report. Once preliminary grading plans become availc1ble, it Is recommended that they be provided to our office for review with regard to the conclusions and recommendations presented herein. In addition, a foundation plan was not available at the time of this report. It is recommended that preliminary foundation plans be provided to our office once they become available. Depending on the results of our review, some modifications to the recommendations contained in this report may be warranted. Settlement The results of the consolidation/collapse testing Indicate that the existing fill soils are not subject to significant collapse upon moisture infiltration. In addition, the existing fill soils do not exhibit significant consolidation when exposed to load increases in the range of those that will be imposed by the new foundations. Provided that the recommendations contained within this r:eport are implemented in the structural design and construction of the proposed buildings, the post-construction settlements are expected to be within tolerable limits. Following completion of the recommended grading, the post-construction static settlements are expected to be within tolerable limits. Cut/Fill Transitions Both buildings are closely underlain -by dense bedrock; It is expected that cuts and fills of up to 1 to 3± will be necessary within these building areas to achieve the proposed subgrade Bressi Ranch, Lots 10-13 -Carlsbad, CA Project No. 07G227-1 Page 15 ( elevations. Therefore, cut/fill transitions are expected tb exist within these building areas after completion of the proposed grading. This cut/fill transition condition at bearing grade raises a potential for additJonal differential settlement. Tnl.s report contains recommendations for additional remedial grading within these building pads to remove this geologic and cut/fill transition, It sho"ld be noted that the extent of areas that will require overexcavation to mitigate cut/fill transitions will depend· upon the final grades that are established throughout the site. Therefore, the extent of this remedial grading may change, following our review of the preliminary grading plan. Expansion Most of the on-site soils consist of medium expansive soils and bedrock (EI = 54). Based on the presence of expansive soils, speci~I care should be taken to properly moisture condition and maintain adequate moisture content within all. subgrade soils as well as newly placed fill soils. The fol!ildation and floor slab design recommendations contained within this report are made in consideration of the expansion index test resul~. It is expected that significant blending of the on-site soils will occur during precise grading procedures, and that the resulting building pad subgrade soils will possess medium expansion ·potentials. It is recommended that additional expansion index testing be conducted at · the completion of precise grading to verify the expansion potential of t,he as-graded building pads. Shrinkage/Subsidence Based on our experience with the on-site soils and rock materials, removal and recompaction of the existing near-:surface engineered fill soils is estimated to result in average shrinkage or bulking of less than 5 percent. Where the existing bedrock is overexcavated and replaced as structural fill, bulking on the order of Oto 5 percent is expected. Minor ground .subsidence is expected to occur in the soils below the zone of removal due to settlement and machinery working. The subsidence is estimated to be 0.1 feet. These estimates may be used for grading in areas that are underlain by existing engineered fill soils. No significant subsidence wlll 01;cur in areas that are immediately underlain by sandstone bedrock. These estimates are based on previous experience and the subsurface conditions encountered at the boring locations. The actual amount of subsidence is expected to be variable and will be dependant on the type of machinery used, repetitions of use, and dynamic effects, all of which are difficult to assess precisely. Setbacks In accordance with Uniform Building Code (UBC) requirements, all footings should maintain a minimum horizontal setback of H/3, where H equals the slope height, measured from the outside fate of the footing to any descending slope face. This setback should not be less than 7 feet, nor need it .be greater than 40 feet. SOUTHERN CALIFORNIA •. _ ---~EOT~CH~I~~L Bressi Ranch, Lots 10-13 -carlsbad, CA Project No. 07G227-1 Page 16 6.3 Site Grading Recommendation• The · grading recommendations presented below are based on the subsurface conditions encountered at the boring locations and our understanding of the proposf;!d development. We recommend that all grading activities be completed in accordance with the Grading Guide Specifications included as Appendix D of this report, µnless superseded by site specific recommendations presented below. · Site Stripping and Demolition Initial site preparation should include stripping of any vegetation and organic debris. Based on conditions observed at the time of the subsurface exploration, moderate stripping of native grass and weeds is expected to be necessary. Initial grading operations should also include abandonment of the existing desilting basins, located throughout the site. Any softened soils, silt deposits, water, or other unsuitable materials should be removed from the detention basin. Removals should extend to a depth of suitable structural compacted fill soils or bedrock. Where the detention basins are located within proposed building areas, the building pad overexcavation recommendations should also be implemented. Treatme!'lt of Existing Soils: . Building Pads Remedial grading will be necessary in several of the building areas to mitigate potential variable support conditions due to cut/fill transitions that will exist at or near the proposed foundation bearing grade. Remedial grading should be performed within both building areas to remove and replace a portion of the dense bedrock as engineered fill. The existing bedrock should be overexcavated to provide for a new layer of compacted structural fill, extending to a depth of at least 3 feet below prqposed foundation bearing grade, throughout the building areas. Based on conditions encountered at the boring locations, it Is expected that such overexcavation will be required throughout both buildings. In general, the overexcavations should extend at least 5 feet beyond the building perimeters. If the propqsed structures incorporate any exterior columns (such as for a canopy or overhang) the area of overexcavation should also encompass these areas. Within areas of the proposed structures that do not require overexcavation per the recommendations presented above, it is recommended that the existing fills be overexcavated to a depth of at least 1 foot below existing grade, to remove any existing weathered and/or softened fill soils, as well as to prepare the subgrade for new fill placement. .Following completion of the overexcavations, the subgrade soils ( or bedrock) within the building areas should be evaluated by the geotechnical engineer to verify their suitability to serve as the structural fill subgrade, as well as to support the fol/ndation loads of the new structure. This Bressi Ranch, Lots 10·13 · Carlsbad, CA Project No. 07G227·1 Page 17 evaluation should include proofrolling with a heavy rubber-tired vehicle to identify any soft, loose or otherwise unstable soils that must be removed. Some localized areas of deeper excavation may be required if loose, porous, or low density soils are encountered at the bottom of the overexcavation. The exposed subgrade soils should then be scarified to a depth of 12 inches, moisture conditioned to 2 to 4 percent above optimum moisture content, and recompacted. Treatment of Existing _Soils: Retaining'. Walls and Site Walls Toe existing soils within the areas of any proposed retaining walls underlain by less than 2 feet of existing engineered fill soils should be overexcavated to a depth of 2 feet below foundation bearing grade and replaced as compacted structural fill, as discussed above for the proposed building pad. Subgrade soils in areas of non-retaining site walls should be overexcavated to a depth of 1 foot below proposed bearing grade, if not underlain by at lest 1 foot of existing engineered fill soils. In both cases, the overexcavation subgrade soils should be evaluated by the geotechnical engineer prior to scarifying, moisture conditioning and recompacting the upper · 12 inches of exposed subgrade soils. In areas where unsuitable fill soils are encountered at foundation Si.Jbgrade level, additional overexcavation or deepened footings will be necessary. The previously excavated soils may then be replaced as compacted structural fill. ·treatment of Existing Soils: Parking Areas Overexcavation of the existing fill soils in the new parking areas is generally not considered warranted~ with the exception of any areas where lower strength soils are identified by the geotechnical engineer during grading. Subgrade .preparation in the remaining new parking areas should Initially consist of completion of cuts where required. The geotechnlcal engineer should then evaluate the subgrade to Identify . any .areas of unsuitable soils. Based on conditions observed at the site at the time of drilling, no significant overexcavation is expected to be necessary within the new parking areas. The subgrade soils should then be scarified to a depth of 12± inches, moisture conditioned to 2 to 4± percent above optimum, and recompacted to at least90 percent of the ASTM D-1557 maximum dry density. Depending upon the actual finished grades, which have not yet been established, portions of the parking lot subgrades may be immediately underlain by bedrock. These materials may be used for direct pavement subgrade support, However, the owner and/or developer of the project should understand that minor amounts of reflective cracking and/or minor differential movements should be expected to occur near the location of the transitions between these bedrock materials and the adjacent engineered fill. If such cracking or minor differential movements within the pavements Is not considered acceptable; additional overexcavation should be performed within the cut portions of the parking areas. Fill Placement • Fill soils should be placed in thin (6± inches), near-horizontal lifts, moisture conditioned to 2 to 4 percent above optimum moisture content, and compacted. Bressi Ranch, Lots 10-13 -carfsbad, CA Project No. 07G227-1 Page 18 • On-site soils may be used for fill provided they are cleaned of any debris or oversized . materials to the satisfaction of the _geotechnlcal engineer •. • All grading arid fill placement activities should be completed in accordance with the requirements of the Uniform Building <;:ode and the grading code of the City of Carlsbad. • All fill soils should be compacted to at least 90 percent of the ASTM D-1557 maximum dry density. Fill soils should.be well mixed .. • Compaction tests should be performed periodically by the geotechnical engineer as random verification of compaction and moisture content. These tests are intended to aid the contractor. Since the tests are taken at discrete locations and depths, they may not be indicative of the entire fill and therefore should not relieve the contractor of his responsibility to meet the job specifications. ImRorted, Structural Fill All imported structural fill should consist of low expansive (EI < 30), well graded soils possessing at least 10 percent fines (that portion of the sample passing the No. 200 sieve). Additional specifications for structural fill are· presented in the Grading Guide Specifications, included as Appendix D. Utility Trench Backfill In general, all utUity trench backfill should be compacted to at least 90 percent of the ASTM D- 1557 maximum dry density. As an alternative, a clean sand (minimum Sand Equivalent of 30) may be placed within trenches and flooded in place. Compacted trench backfill should conform to the requirements of the local grading code, and more restrictive requirements may be indicated by the City of Carlsbad; Materials used to backfill trenches should consist of well graded granular soils with a maximum particle size of 3 inches. All utility trench backfills should .be witnessed by the geotechnicai engineer. The trench backfill soils should be compaction tested where possible; probed and visually evaluated elsewhere. Utility trenches which parallel a footing, and extending below a lh:lv plane projected from the outside ec;lge of the footing should be backfilled with strl!ctural fill soils, compacted to at least 90 percent of the ASTM D-1557 stanqard. Sand or pea· gravel· backfill, unless it is similar to the native soils, should not be used for these trenches. · 6.4 Construction Considerations Moisture Sensitlve.Subgrade Soils Some of the near surface soils possess appreciable silt and clay content and may become unstable if exposed to significant moisture infiltration or disturbance by construction traffic. In addition, based on their granular content, the on-site soils will also be susceptible to erosion. The site should,· therefore, be graded to prevent pondjng of surface water and to prevent water from running into excavations. · Bressi Ranch, Lots 10-13 -Carlsbad, CA Project No. 07G227-1 Page 19 Excavation Considerations Based on conditions encountered at the boring locations, the bedrock that underlies the subject site possesses a dense to very dense relative density, but is somewhat friable. It is expected that it wfll be feasible to utlllze conventional grading equipment within the depths that were explored 'by the borings. However, some difficulty may be encountered during excavation, possibly requiring large single shank-equipped bulldozers, excavators, etc. The grading contrag:or should' verify the need for special excavation equipment prior to bidding the project. Based on the presence of moderate granular content of the soils throughout the development area, minor to moderate caving of shallow excavations may occur •. Flattened excavation slopes may .be sufficient to mitigate c;aving of shallow excavations, although deeper excavations may require some form of external stabilization such as shoring or bracing. Temporary excavation slopes should be no steeper than 1h:lv. All excavation activities on this site should be conducted in accordance with Cal-OSHA regulations. Expansive Soils As previously discussed, the on site soils have been determined to possess a medium expansion potential. Therefore, car.e should be given to proper moisture conditioning of all building pad subgrade soils to a moisture content of 2 to 4 percent above the Modified Proctor optimum during site grading. All imported fill soils should have low to-medium expansive characteristics. In addition to adequately moisture conditioning the subgrade soils and fill soils during grading, special care must be taken to maintain the moisture content of these soils at 2 to 4 percent above the Modified Proctor optimum. This will require the contractor to frequently moisture condition these soils throughout the grading process, unless ·grading occurs during a period of relatively wet weather. Due to the presence of expansive soils at this site, provisions should be made to limit the potential for surface water to penetrate the soils Immediately adjacent to the structures. These provisions should include directing surface runoff into rain gutters and area drains, reducing the extent of landscaped areas around the structures, and sloping the ground surface away from the buildings. Where possible, it is recommended that landscaped planters not be located immediately adjacent to the proposed buildings. If landscaped planters around the buildings are necessary, it is recommended that drought tolerant plants or a drip irrigation system be utilized, to minimize the potential for deep moisture penetration -around the structure. Other provisions, as determined by the civil engineer may also be appropriate. Elevator Equipment Shafts It ·is expected that the proposed three story buildings will incorporate at least one elevator. Typically these elevators require installation of relatively large diameter steel pipes as part of the elevator counterweights. It is expe~ed that the pipes will be installed within slightly oversized borings. Where these pipes are installed, the annulus between the borehole wall and the elevator pipe should be backfilled with a lean concretEl slurry or grout. Placement of loose backfill soils around these pipes could result in localized settlement of the structural fill soils and/or foundation elements. ~ SOUTHERN ,...,. I CAUFORNiA ,. ____ GEOTECHNICAL Bressi Ranch, Lots 10-13 -Carlsbad, CA Project No. 07G227-1 Page 20 Groundwater Free water was not encountered within the depths explored by the borings drilled for this project. These borings extended to a maximum depth of 20± feet below existing grade. Based on this information, groundwater is not expected to impact the proposed grading or foundation construction activities. 6.5 Foundation Desi9n and Coristructi_on Based on the preceding preliminary grading recommendations, it is assumed that the new b1.,1ilding pads will be Immediately underlain by existing or newly placed structural fill soils extending to depths of at least 3± feet below foundation bearing grade. Based on this subsurface profile, the proposed structures may be supported on conventional shallow foundation systems. Foundation Design Parameters New square and rectangular footings may be designed as follows: • Maximum, net allowable soil bearing pressure: 2,500 lbs/ft:2. The allowable bearing pressure may be increased by 1/3 when considering short duration wind or seismic loads. • Minimum wall/column footing width: 14 inches/24 inches • Minimum lotlgitudinal Steel reinforcement within strip footings: Four (4) No. 5 rebars (2 top and 2 bottom), due to medium expansive potential of near surface soils. • Minimum foundation embedment: 12 inches into suitable structural fill soils, and at least 18 inches below adjacent exterior grade. Interior column footings may be placed immediately beneath the. floor slab. • It is recommended that the perimeter: foundations be continuous across all exterior doorways. Flatwork adjacent to exterior doors should be doweled into the perimeter foundations in a manner determined by the structural engineer. The minimum steel reinforcement recommended above is based on geotechnlcal considerations. Additional reinforcement may be necessary for structural considerations. The actual design of the foundations should be determined by the structur~I engineer. Foundation Construction The foundation subgrade soils should be evaluated· at the time of overexcavation, as discussed in Section 6.3 of this report. It is· further recommended that the foundation subgrade soils be evaluated by the geotechriical engineer immediately prior to steel or concrete placement. Soils suitable for direct foundation support should consist of newly placed structural fill, compacted to at le~st 90 percent of the ASTM D~1557 maximum dry density. Any unsuitable bearing .... SOUTHERN ......,. I CALIFORNIA ,, _____ .. GEOTECHNICAL Bressi Ranch, Lots 10·13 • Carlsbad, CA Project No. 07G227-1 Page 21 materials should be removed to a depth of suitable bearing compacted structural fill, with the resulting excavations backfille(I. with compacted .fill soils. As an alternative, lean concrete slurry (500 to 1,500 psi) may be used to backfill such isolated overexcavations. The foundation subgrade soils should also be properly moisture conditioned to 2 to 4 percent above the Modified Proctor optimum, to a depth of at least 12 inches below bearing grade. Estimated .Foundation Settlements Post:-constructiori total and differential settlements induced by the foundation loads of the new structures are estimated to be less than 1.0 and 0.5 inches, respectively, for shallow foundations designed and constructed in accordance with the recommendations provided In this report. The differential movements are expected to occur over a 30-foot span, thereby resulting in an angular distortion of less than 0.002 inches per inch. Lateral Load Resistance Lateral load resistance will be developed by a combination of friction acting at the base of foundations .and slabs and the passive earth pr.essur.e developed by footings below grade. The following friction and passive ,pressure may be used to resist lateral forces: • Passive Earth Pressure: 250 lbs/ft' • Friction Coefficient: 0.25 These are allowable values, arid include a factor of safety. When combining friction and passive resistar:,ce, the passive pressure component should be reduced by one-third. These values assume that footings will be poured directly against suitable compacted structural fill. The maximum allowable passive pressure is 2500 lbs/ft'. 6.6 Floor Slab Design and Construction Subgrades which will support new floor slabs should be prepared in accordance with the recommendations contained in the Site Grading Recommendations section of this report. Based on the anticipated grading which will occur at this site, the floors of the new structures may be constructed as conventional slabs-on-grade supported on newly placed structural fill. Based on· geotechnlcal considerations, the floor slabs may be designed as follows: • Minimum slab thickness: 5 inches • Minimum slab reinforcement: No. 3 bars at 18-inches on-center, in both directions. • Slab underlayment: 10-mil vapor barrier, overlain by 2 inches of clean sand. Where moisture sensitive floor coverings are not anticipated, the vapor barrier and 2-inch layer of sand may be eliminated. SOUTHERN CALIFORNIA .... _ _ GE.OTE~~~I~~L Bressi Ranch, Lots 10-13 -Carlsbad, CA Project No. 07G227-1 Page 22 1/ ,:,. • Moisture condition the floor slab subgrade soils to 2 to 4 percent above optimum moisture content, to a depth of 12 inches. Proper concrete curing techniques should be utlllzed to reduce the potential for slab curling or the formation of excessive shrinkage cracks. 6.7 Retaining Wall ·Design Recommendations It is expected that some small retaining walls may be required to facilitate the new site grades. The parameters recommended for use in the design of these walls are presented below. Retaining_ Wall Desjgn Parameters Based on the son conditions encountered at the boring locations, the following parameters may be used-in the design of new retaining walls for this site. We have provided parameters for two different types of wall backfill: on .. site soils consisting of silty sands and clayey sands; and imported select granular material. In order to use the design parameters for the imported select fill, this material must be placed within the entire active failure wedge. This wedge is defined as extending from the base of the retaining wall upwards at a 59 degree angle of inclination. RETAINING WALL DESIGN PARAMETERS - Soil T•,oe Qesign Parameter Imported On-Site Aggregate Base Silty Sands and -Clayey Sands Internal Friction Angle (~} 38° 28° Unit Weight 130 lbs/ft' 125 lbs/ft' Active Condition 31 lbs/ft' 45 lbs/ft' (level backfill) Equivalent Fluid Active Condition Pressure: (2h:lv backfill) 44 lbs/ft' 79 lbs/ft' At~Rest Condition 48 lbs/ft' 66 lbs/ft' (level backfill) Regardless of the backfill type, the walls should be designed using a soil-footing coefficient of friction or 0.25 and an equivalent passive pressure of 250 lbs/ft'. The active earth pressures may be used for the design of retaining walls which do not directly support structures or support solls which in turn support structures and which wlll be allowed to deflect. The at-rest earth pressures should be used for walls which will not be allowed to deflect such as those which will support foundation bearing soils,. or which will support foundation loads directly. ~ SOUTHERN .......,.. 1 CALIFORNIA ,,, ___ GEOTECHNICAL Bressi Ranch, Lots 10-13 -carlsbad, CA Project No. 07G227-1 Page 23 Where the soils on the toe side of the retaining wall are not covered by a "hard" surface such as a structure or pavement; the upper 1 foot of soil should be .neglected when calculating passive resistance due to the potential for the material to become disturbed or degraded during the life of the structure. Retaining Wall Foundation Design Retaining walls should be supported within newly placed structural fill monitored during placement by the geotethnical engineer. Where retaining walls are also serving as building walls, they should be graded iii accordance with the recommendations presented in Section 6.3 of this report for the proposed building pad· areas. Foundations to support new retaining walls should be designed In accordance with the general Foundation Design Parameters presented in a previous section of this report. Backfill Material It is recommended that a minimum 1 foot thick layer of free-draining granular material (less . than 5 percent passing the No; 200 sieve) should be placed against the face of the retaining walls. This material should be approved by the geotechnical engineer. A suitable geotextile should be used to separate the layer Of free draining granular material from the backfill soils. If the layer of free-draining material is not covered by an impermeable surface, such as a structure or pavement, a 12-lnch thick layer of a low permeability soil should be placed over the backfill to reduce surface water migration to the underlying soils. All retaining wall backfill should be placed and compacted under engineering controlled conditions in the necessary layer thicknesses to ensure ,m in-place density between 90 and 93 percent of the maximum dry density as determined by the Modified Proctor test (ASTM D1557- 91). Care should be taken to avoid over-compaction of the soils behind the retaining walls, and the use of heavy compaction equipment should .be avoided, Subsurface Drainage As previously indicated, the retaining wall design parameters are based upon drained backfill conditions. Consequently, some form of permanent drainage system will be necessary in conjunction with the appropriate backfill material .. Subsurface drainage may consist of either: A weep hole drainage system typically consisting of a series of 4-lnch diameter holes in the wall situated slightly above the ground surface elevation on the exposed side of the wall and at an approximate. 8-foot on-center spacing. The weep holes should include a minimum 2 cubic foot gravel pocket surrounded by an appropriate geotextile fabric at each weep hole location. • A 4-,inch diameter perforated pipe surrounded by 2 cubic feet of gravel per linear foot of drain placed behind the retaining wall, above the footing. The gravel drain should be wrapped in a suitable geotextile fabric to reduce the potential for migration of fines. The footing drain should be extended to daylight or tied into a storm drainage system. SOUTHERN ' . CALIFORNIA ...... G.EQip~[!i!~A~ Bressi Ranch, Lots 10-13 -carlsbad, CA Project No, 07G227·1 Page 24 6.s Pavement Design Parameters Site preparation in the pavement area should be completed as previously recommended in the Site Grading Recommt11ndation$ section. of this report. The subsequent preliminary pavement recommendations assume proper drainage and construction monitoring, and are based on either PCA or CAL TRANS design parameters for a twenty (20) year design period. These preliminary designs also assume a routine pavement maintenance program to obtain the 20-year pavement service life. Pavement Subqrades It is anticipated that the new pavements wlll be primarily supported on a layer of compacted structural fill, consisting of scarified, thoroughly moisture conditioned and: recompacted native materials and/or fill soils. The on-site soils generally consist of sandy clays and sandy clays. These soils are considered to possess fair pavement support characteristics with R-values of 10 to 20. Since R-value testing was not inciuded in the scope of services for this project, the subsequent pavement design is based upon an assumed R-value of 15. Any fill material imported to the site should have support characteristics equal to or greater than that of the on-site soils and be placed and compacted under engineering controlled conditions. It is recommended that R-value testing be performed after completion of rough grading. Depending upon the results of the R-value testing, it may be feasible to use thinner pavement sections in some areas of the site. Asphaltic Concrete The pavement designs are based on the traffic indices (Tl's) indicated. The client and/or civil engineer should verlfy that these Tl's are representative of the anticipated traffic volumes. If the client ahd/or civil engineer determine that the expected traffic volume will exceed those recommended herein, we should be contacted for supplementary recommendations. The design traffic indices equate to the following approximate daily traffic volumes over a 20-year design life, assuming 5 operational traffic days per week: Traffic Index No. of Heavv Trucks per Dav 4.0 .. o_ 5.0 . 1 6.0 3 7.0 11 For the purposes of the traffic volumes above, a truck is defined as a 5-axle tractor-trailer unit, with one 8-kip axle and two 32-kip tandem axles. All of the traffic indices allow for 1000 automobiles per day. · Presented below are the recommended thicknesses for new flexible pavement structures consisting of asphaltic concrete over a granular base'. It should be noted that the TI = 5.0 sectiQn only allows for 1 truck per day. Therefore, ail. significant .heavy truck traffic must be excluded from areas where this thinner pavement section is used; otherwise premature pavement distress may occur. SOUTHERN ' ' CALIFORNIA T. .. G~OTE_½ij_~-~t Bressi Ranch, Lots 10-13 -carlsbad, CA Project No. 07G227-1 Page 25 ASPHALT PAVEMENTS .·. Thickness (inches) Materials Auto Parking Auto Drive Light Truck Moderate Lanes· Traffic Truck Traffic (TI= 4.5) <Ti= 5.51 (TI= 6.0) (TI= 7.0) Asphalt Concrete 4 4 4 4 Aggregate Base 5 8 10 13 Compacted Subgrade 12 12 12 12 (90% minimum compaction)· The aggregate base course should be compacted to at least 95 percent of the ASTM D-1557 maximum dry density. The asphaltic concrete should be compacted to at least 95 percent of the Marshall maximum density, as determined by ASTM b-2726. The aggregate base course may consist of crushed aggregate base (CAB) or crushed· miscellaneous base (CMB), which is a recycled gravel, asphalt and concrete material. The gradation, R-Value, Sand Equivalent, and Percentage Wear of the CAB or CMB should comply with appropriate specifications contained in the current edition of the "Greenbook" Standard Specifications for Public Works Construction. Portland Cement Concrete The preparation of the subgrade soils within concrete pavement areas should be performed as previously described for proposed asphalt pavement areas~ Since significant portions of the granitic bedrock are expected to be removed around the perimeters of the proposed structures where the Portland cement concrete pavements wlll be located, the pavement design presented below is based on the presence of existing or newly placed compacted structural fill immediately beneath the proposed pavement subgrade elevation. The minimum recommended thicknesses for the Portland Cement Concrete pavement sections are as follows: PORTLAND CEMENT CONCRETE PAVEMENTS - · Thickness (inches) Materials Drive Lanes (71 = Moderate Truck Automobile Parking · · · ·S.5} .and Light Truck Traffic (TI= 4.5) Traffic (TI= 7.0) m = 6.o) PCG 5 5½ 7 . --- Compacted Subgrade 12 12 12 (95% minimum compaction) The concrete should have a 28-day compressive strength of at least 3,000 psi. Reinforcing within all pavements should consist of at least heavy welded wire mesh (6x6-W2.9xW2.9 WWF) plc1ced at mid-height in the slab. In areas underlain by expansive soils, the reinforcement should ...., SOUTHERN ..,.,. I CALIFORNIA ,, ___ ... GEOTECHNICAL Bressi Ranch, Lots 10°13 -Carlsbad, CA Project No. 07G227-1 Page 26 be increased to No. 4 bars at 18 inches on center. The maximum joint spacing within all of the PCC pavements is recommended to beequcil to or lessthan 30 times the pavement thickness. .... SOUTHERN ~ 1 CALIFORNIA ,, .. --.~Eor~_q!_NI~-~1 Bressi Ranch, Lots 10-13 -carlsbad, CA Project No. 07G227-1 Page 27 7.0 GENERAL COMMENTS This report has been prepared as an instrument of service for use by the client in order to aid in the evaluation of this property and to c!SSist the architects and engineers in the design and preparation of the project plans and specifications. This report may be provided to the contractor(s) and other design consultants to disclose information relative to the project. However, this .report is not intended to be utilized as a specification in and of itself, without . appropriate interpretation by the project architect, structural engineer, and/or civil engineer. The reproduction and distribution of this report must be authorized by the client and Southern California Geotechnical, Inc. Furthermore, any reliance on this report by an unauthorized third party is at such party's sole risk, c:md we accept no responsibility for damage or loss which may occur. The analysis of this site was based on a subsurface profile interpolated from limited discrete soil samples. While the materials encountered 'iri the project area are considered to be representative of the total area, some variations should be expected between boring locations and sample depths. If the conditions encountered during coristruction vary significantly from those detailed herein, we should .be contacted immediately to determine if the conditions alter the recommendations contained herein. This report has been based on assumed or provided characteristics of the proposed development. It is recommended that the owner, client, architect, structural engineer, and civil engineer carefully review these assumptions to ensure that they are consistent with the characteristics of the proposed development. If discrepancies exist, they should be brought to our attention to verify that they do not affect the conclusions and recommendations contained herein. We also recommend that the project plans and specifications be submitted to our office for review to verify that our recommendations hav(;! been correctly interpreted. The analysis, conclusions, artd recommendations contained within this report have been promulgated in accordance with generally accepted professional geotechnical engineering practice. No other warranty is implied or expressed. SOUTHERN . . ' CALIFORNIA T-.. G.EQTE~!mi~~t Bressi Ranch, Lots 10-13 -Carlsbad, CA Project No. 07G227-1 Page 28 : ; . POOR . . . . . · QUALITY . · . ' · · O'RIGINAL S ' . . \ ._,, ;... ,.,.~.,.,· !n;OR(o~ + . "'·'i ~1 •• f s~rc §' ...... l'AIX ,FARAO~Y , ... ~f.~, ........... . SOURCE: SAN DIEGO COUNTY THOMAS GUIDE, 2007 SITE LOCATION MAP BRESSI RANCH INDUSTRIAL PARK 1:··= 2400' DRAWN: TRS CHKD:GKM_ SCGPROJECT 07G226-1 PLATE 1 CARLSBAD, CALIFORNIA • SOUTHERN CALIFORNIA .. GEOTECHNICAL ,. \ · ' \!l . () .\ ~ ~, z \q . \,, ;~ r ·,1\ . ;\ . ·.t ,J, I I I I I I I I I I I I I PREVIOUS BORING LOCATION (SCG PROJECT NO. 06G252-1) PREVIOUS BORING LOCATION (SCG PROJECT NO. 05G273·1) Ale. ENGINEERED FILL Tsa. SANTIAGO FORMATION _ _ _ GEOLOGIC CONTACT NOTE: B>.SE MAP PROVIDED BY SMITH CONSULTING ARCHITECTS BORING LOCATION PLAN BRESSI RANCH INDUSTRIAL PARK CARLSBAD, CALIFORNIA =•··"' • SOUTHERN '='•': CALIFORNIA ~:;';)" -GEOTECHNISAL PLATE2 T ·- .. POOR . . ·. QUALITY '. tr 1:; , ' : . ·· ORIGINAL S . ' •.. ·l ' L BORING LOG LEGEND SAMPLE TYPE GRAPHICAL SYMBOL SAMPLE DESCRIPTION AUGER SAMPLE COLLECTED FROM AUGER CUTTINGS, NO FIELD'MEASUREMENT OF SOIL STRENGTH. (DISTURBED) CORE GRAB cs NSR SPT SH. VANE COLUMN DESCRIPTIONS DEPTH: SAMPLE: BLOW COUNT: POCKET PEN.: GRAPHIC LOG: DRY DENSITY: MOISTURE CONTENT: LIQUID LIMIT: PLASTIC LIMIT: PASSING #200 SIEVE: UNCONFINED SHEAR: ROCK CORE SAMPLE: TYPICALLY TAKEN WITH A DIAMOND-TIPPED CORE BARREL. TYPICALLY USED ONl Y IN:HIGHL Y CONSOLIDATED BEDROCK. SOIL SAMPLE TAKEN WITH NO SPECIALIZED EQUIPMENT, SUCH AS FROM A STOCKPILE OR THE GROUND SURFACE. (DISTURBED) CALIFORNIA SAMPLER: 2-1/2 INCH 1.0. SPLIT BARREL SAMPLER, LINED WITH 1-INCH HIGH BRASS · RIN_GS. DRIVEN WITH SPT HAMMER. (RELATIVELY UNDISTURBED) NO RECOVER: THE SAMPLING ATTEMPT DID NOT RESULT IN RECOVERY OF ANY SIGNIFICANT SOIL QR ROCK MATERIAL. STANPARD Pl;NETRAT!ON TEST: SAMPLER IS A 1.4 . INCH INSIDE DIAMETER SPLIT BARREL, DRIVEN 16 INCH~S WITH THE SPT HAMMER. (DISTURBED) SHEBLY T_UBE: TA.KE~ WITH A THIN WALL SAMPLE TUBE,.PUSHED INTO THE SOIL AND THEN EXTRACTED. (UNDISTURBED) VANE SHEAR TEST: SOIL STRENGH OBTAINED USING A 4 BLADED SHEAR DEVICE. TYPICALLY USED IN SOFT CLAYS-NO SAMPLE RECOVERED. Distance in feet below the ground surface. Sample Type as depicted above. Number of blow required to advance the sampler 12 inches using a 140 lb hammer with a 30-inch drop. 50/3" indicates penetration refusal (>50 blows) at 3 inches. WH indicates. that the weight of the hammer was sufficient to push the sampler 6 inches or more. Approximate shear strength of a cohesive soil sample as measured by pocket penetrometer. · Graphic Soil Symbol as depicted on the following page. Dry density of an undisturbed or relatively undisturbed sample. -Moisture content of a soil sample, expressed as a percentage of the dry weight. The moisture content above which a soil behaves as a liquid. The moisture content above which a soil behaves as a plastic. The percentage of the sample finer than the #200 standard sieve. The shear strength of a cohesive soii sample, as measured in the unconfined state. · '' SOIL CLASSJFICATION· CHART MAJOR DIVISIONS COARSE GRAINED SOILS MORE THAN 50% OF MATERIAL IS LARGER THAN NO. 200 SIEVE SIZE FINE GRAINED SOILS MORE THAN 50% OF MATERIAL IS SMALLER THAN NO. 200 SIEVE SIZE GRAVEL AND GRAVELLY SOILS MORE THAN 50% OF COARSE FRACTION RETAINED ON NO. 4SIEVE SAND AND SANDY SOILS SILTS AND CLAYS SILTS AND CLAYS CLEAN GRAVELS (LITTLE OR NO FINES) GRAVELS WITH FINES (APPRECIABLE AMOUNT OF FINES) CLEAN SANDS LIQUID LIMIT LESS THAN 59 LIQUID LIMIT GREATERTHAN 50 HIGHLY ORGANIC SOILS SYMBOLS GRAPH LETTER ,,~~~' ~ ~ ,,,, ,,, GW GP GM GC SW SP ML CL MH CH OH PT NOTE: DUA~.~YMBOLS ARE USl;D TO INDICATE BORD~RLINE SOll.CLASSIFICA;J"IONS TYPICAL DESCRIPTIONS WELL-GRADED GRAVELS, GRAVEL- SAND MIXTURES, LITTLE OR NO FINES POORLY-GRADED GRAVELS, GRAVEL -SAND MIXTURES, LITTLE ORNO FINES SIL TY GRAVELS, GRAVEL -SAND· SILT MIXTURES CLAYEY GRAVELS, GRAVEL -SAND· CLAY MIXTURES WELL-GRADED SANDS, GRAVELLY SANDS, LITTLE OR NO FINES POORLY-GRADED SANDS, GRAVELLY SAND, LITTLE OR NO FINES SILTY SANDS, SAND -SILT MIXTURES CLAYEY SANDS, SAND -CLAY MIXTURES INORGANIC SIL TS AND VERY FINE SANDS, ROCK FLOUR, SIL TY OR CLAYEY FINE SANDS OR CLAYEY SIL TS WITH SLIGHT PLASTICITY INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY, GRAVELLY CLAYS, SANDY CLAYS, SILTY CLAYS, LEAN CLAYS ORGANIC SIL TS AND ORGANIC SIL TY CLAYS OF LOW PLASTICITY INORGANIC SILTS, MICACEOUS OR DIATOMACEOUS FINE SAND OR SILTY SOILS INORGANIC CLAYS OF HIGH PLASTICITY ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY, ORGANIC SILTS PEAT, HUMUS, SWAMP SOILS WITH HIGH ORGANIC CONTENTS '. "' ~ b ' • C) g ~ g 2 C) § $ ..J JOB NO.: 07G227 • SOUTHERN CALIFORNIA .. GEOTE~HNI~_AL DRILLING DATE: 12/28/07 PROJECT: . Bressi PA 3 Lots 10-13 LOCATION: Carlsbad, California DRl~LING METHOD: Hollow Stem Auger LOGG~D BY: Tim Smith _ FIELD RESULTS 1-z ::::,. 0 w (.) :c ..Ja. > ~ :B. 0 !!5 ~ al 5 10 15 . DESCRIPTION SURFACE ELEVATION: 304 feet MSL SANTIAGO FORMATION BEDROCK: White Sandy Siltstone, some Iron oxide-staining, friable, very dense-damp Light Gray to Light Brown Siltstone, trace fine Sandy Silt layers, some Clay, thinly bedded, some calcareous nodules, very dense-damp to moist Light Gray to·Light Brown Silty Sandstone; some Iron oxide staining, friable, very dense-damp Light Brown Sandy Siltstone, some calcareous veining, friable, very dense-damp to moist · Boring Terminated at 19½' BORING NO. WATER DEPTH: Dry CAVE DEPTH: 13 feet READING TAKEN: At Completion B-1 LABORATORY RES UL TS 108 11 111 13 109 17 106 12 107 2Q 14 19 1:!.__ ........ __.. ...... __._ _ _.__..._ __________________ __,....__....._ ........ _ _,__..,___....___. ____ __, TEST BORING LOG PLATE B-1 -, •. i L JOB NO.: 07G227 • SOUTHERN CALIFORNIA ~ GEOTE~~~~~-~~ DRILLING DATE: 12/28/07 PROJECT: Bress·i PA 3 Lots 10-13 DRILLING METHOD: Hollow Stem Auger LOCATION: Carlsbad, California LOGGED BY: Tim Smith FIELD RESULTS I. !ii' I-;i C) z .·~ 0 DESCRIPTION w ;:::i ..J !:.. 0 () W· () I-:i: :c .;J ~ w I-.0.. the 0.. 0.. '~--· 0 ~-UJ ·4: ..J ocn SURFAQE ELEVATION: 306 feet MSL 0 Cl) al ' 0.. t:::. C) Itri FILL: Light Brown to Brown fine Sand, trace medium Sand, X 25' trace Silt, trace Iron oxide staining, medium dense-moist ~ tx 22 Jl!} 5 [X 45, ):\/ FILL: Orange to Gray SIity fine Sand, trace medium Sahd, dense-moist \::i:\ r>< SANTIAGO FORMATION BEDROCK: Light Gray to Light 40 Brown Silty fine Sandstone, some Iron oxide staining, dense-moist 10-<-- )\' 26 15 ~ Red Brown Siltstone, ·trace fine Sand, trace calcareous. X 39 I veining, dense-moist to very moist . ' Boring Terminated .at 19½' TEST BORING LOG BORING NO. B-2 WATER DEPTH: Ory CAVE DEPTH: 16 feet READING TAKEN: At Completion LABORATORY RESULTS ~ ~ ~ ~ o~ 0 WU. ~ ci5 w.,... w ~g z 0::: I-C>Gj z w ~z () z-Zo:: w 0~ 1-W 0 tit--Cl) ~ >-u.. cnt--1-(/)0 8iti ~ .65 ~-:5:E cno o::U 0~ 4; N z:c 0 .a,8::, ~() :::i:::i 0.. :::i 0..'11: ~Cl) () 12 16 14 16 21 28 '' PLATE B-2 a, 0 :;;, JOB NO,: 07G227 • SOUTHERN CALIFORNIA ~ GEOTE~HNI.~~~ DRILLING DATE: 12/28/07 . PROJECT: Bressi PA 3 Lots 10-13 LOCATION: Carlsbad, California . DRILLING METHOD: Hollow Stem Auger LOGGED BY: Tim Smith FIELD RESULTS p !z w w :::, !!::. w 0 (.) :x: _, ;;: t-, C. C. ~ g w C (/) m 65 45 5 79 46 54 10 15 DESCRIPTION SURFACE ELl;:VATION: 307 feet MSL FILL: Brown fine Sand, some Silt, some Shell fragments, little ·cIay,_ some Iron oxide staining, dense-to very dense-damp to moist SANTIAGO FORMATION BEDROCK: Light Gray Silty Sandstone, trace medium Sand, dense-moist SANTIAGO FORMATION BEDROCK: Gray fine Sandy Siltstone, friable, dense-moist Boring Terminated at 19½' S! . b (!) I [il & ~ ~ .., BORING NO. 8-3 WATER DEPTH: Dry CAVE DEPTH: 16 feet READING TAKEN: At Completion .LABORATORY RESULTS 107 9 107 18 109 13 107 14 111 14 106 16 107 18 ~ z w ~ ~ 0 (.) 1!!.____..,__.____._ _ ___._ _ _.._ __ -________________ _._ _ _..___-J.___.._ _ _.__...,___.__ ___ ___. TEST BORING LOG PLATE B-3 ! ,. SOUTHERN ' . . ' CALIFORNIA ~ GEOTE~HN~~-AL BORING NO. B-4 JOB NO.: 07<3227 DRILLING DATE: 12/28/97 WATER DEPTH: Dry PROJECT: Bressi PA 3 Lots 10-13 DRILLING METHOD: Hollow Stem Auger CAVE DEPTH: 12 feet LOCATION: Carlsbad, California LOGGED BY: Tim Smith READING TAKEN: At Completion Fl~LD RESU~ TS LABORATORY RESULTS ~ p I-z (!) it: ~ e Cl~ z 0 :,!? w w DESCRIPTION 0 UJ u. U) UJ :::> a.. ...J ci5 w ...... w ZUl I- !:!::. w 0 I-(.) z C".: !z (.) (!)> U:: t:. z J: ...J (.) w 5: w =>w Cl t; ..... z!!! zo:: w Ii: a.. 3: ~~ a.. Cl~ .......... -U) 0<( ~ -1-U)o ~ 0 (.)U. ~ >-u. ~z :::>-:5~ ~o (.)W ~ w c( ...J-oUl SURFACE ELEVATION: 304 feet fv1Sl o::U oo 0~ ZJ: 0 Cl '([), Ill a.. t:. (!) Cle:. ~(.) ::J ::J a.. '.J a..~ :::> (/) (.) ~--FILL:, Brown Clayey fine Sand, trace medium Sand, .trace ~ 18 ~--Shell fragments, medium dense-moist 19 ·~ ~ 20 17 -~-'/-.·,;;, 5 8;·":I, ··,.·~· ~ 26 '/\./ FILL: Light Brown Silty fine Sand, trace calcareous veining, trace Iron oxide staining, medium dense-moist 15 '•: .• -:: :: ~= :··:·-.: tx SANTIAGO FORMATION BEDROCK: Gray Silty Sandstone, 23 little Clay, thinly'beaded, friable, ·medium.dense to 12 dense-damp to moist 10- lX 32 24 -,~ Boring Terminated at 15' TEST BORING LOG PLATE 8-4 .. ' L ., i b C!) fii C!) ~ 0 "' 2 C!) ~ ~ ~ JOB NO.: 07G227 • SOUTHERN CALIFORNIA • GEOTECHNIC.AL BORING NO. 8-5 DRILLING DATE: 12/28/07 WATER DEPTH: Dry PROJECT: Bressl'PA 3 Lots 10-13 LOCATION_: Carls~i:id, California DRILLING.ME·THOD: Hollow Stem Auger CAVE DEPTH: 15 feet LOGGED BY: Tim Smith READING TAKEN: At Completion FIELD RES UL TS. ~ I-z (9 z w 0 w :::,, a. ...J ·.!::, -~ 0 I-0 ~ 0 w :i: a. 8 ~-a. a. ~ (.) u. ~ w _J, ·~~ Cl (/) aJ (9 5 10 15 DESCRIP"TION SURFACE ELEVATION: 309 feet MSL FILL: Brown·Clayey fine Sand, some Silt, so.me Iron oxide staining, moderately cemented, medium dense-damp SANTIAGO FORMATION BEDROCK: Brown Gray Sandstone, friable, some Iron oxide staining, medium dense-damp to moist SANTIAGO FORMATION BEDROCK: Gray fine Sandy Siltstone, little Clay, ~ome Iron oxide staining, medium dense-moist 'SANTIAGO FORMATION BEDROCK: Gray Sandy Siltstone, friable, dense to very dense-m9ist SANTIAGO FORMATION BEDROCK: Gray.Silty Sandstone, trat;e Iron oxide·staining, friable, dense-moist Boring terminated at 19½' LABORATORY RESULTS 109 8 El = 54@ 0 to 5' 107 · 8 99 15 101 20 111 15 14 18 .__ ....... """'""'----'----'---'-------,----'--'-----'------------'--.__---'---'--__,__...____, ____ __, TEST BORING LOG PLATE 8-5 I b (!) 53 ~ 0 rn ~ (!) ~ E; JOB NO.: 07G227 • SOUTHERN CAUFORNIA ... GEOTE~HNI~-~-L DRILLINGDATE: 12/28/07 PROJE~T: Bressi-PA3 Lots 10-13 LOCATION: Carlsbad, California DRILLING METHOD: Hollow Stem Auger LOGGED B,Y: Tif11 S111ith FIELD RES UL TS· I=' I-z w z w . :::> w ~ 0 a.' w (.) Iii J: ..J ~ I-a. ::.::~ a. ::!!: (.)U. w ~ -o,(/)· 0 Ill a.t:::. 5 10 15 (!) g (.) :i: a. ~ (!) DESCRIPTION SURFACE ELEVATION: 308 feet MSL SANTIAGO FORMATION BEDROCK: Gray Silty Sandstone, friable, abundant Iron oxide staining, dense-damp to moist SANTIAGO FORMATION BEDROCK: Light Brown to Gray Claystone, trace to some fine Sand, s9me lrein oxide staining, friable, very stiff to hard-moist · Boring terminated at 19½' BORING NO. 8-6 WATER DEPTH: Dry CAVE DEPTH: 16 feet READING TAKEN: At Completion LABORATORY RESULTS ~ ~ C o~ '#. wu. ~ 1i5 w~ w Z(/) z C!'. !z <.!lGj u::t:::. z w i:?w (.) z-ZC!'. w 0~ 0 ti1--(/) ::!!: ·(I) I--1-(/)0 8u1 >-u. -z =>-:s~ (/)0 ~ C!'.(.) oo 0~ <(N ZJ: 0 oe:. ,~(..) :::i:::i a. :::i a.'"' :::> (/) (..) 20 11 19 20 18 23 ..J l!:1---......1._i...........1.-.....L..--"....L....-------------'-------...l.--'-,----L---'--....L....--'----'---------' TEST BORING LOG PLATE B-6 b I. ~ @ ~ 0 (/) 2 ~ ~ _, JOB.NO.: 07G227 • . SOUTHERN CALIFORNIA • GEOTECHNIC_AL DRILLING DATE: 12/28/07 PROJECT: BressiPA 3 lots 10-13 LOCATION:: Carlsbad, Californi!I DRILLING METHOD: Hollow Stem Auger LOGGED BY: Tim Smith FIELD RESULTS r=-I-:i z w w w ::> a. !::. 0 W· I- ~ ..J u w c.. ~ nu:-c.. ::l: w <( ~~ 0 Cl) CXl 5 10 15 0 0 ..J u :i: c.. ii . ' C!> DESCRIPTION SURFACE ELEVATION: . 312 feet MSL SANTIAGO FORMATION BEDROCK: Gray Silty fine grained Sandstone, little Iron oxide staining, dense-moist SANTIAGO FORMATION BEDROCK: Gray Silty fine grained Sandstone, some Iron oxide staining, trace medium Sand, very dense-damp·to moist Boring Terminated at 19½' BORING NO. 8-7 WATER DEPTH: Dry CAVE DEPTH: 15feet READING TAKEN: At Completion ·. LABORATORY RESULTS >-~ ~ o~ 0 != ~ 0 w u. en ,(/) w~ w zcn I-z ocl-c,> -1-z :::iZ u u.~ w 1-W 0 ~I- z!:!:! z oc w 0~ -(/) 8~ ::l: C/l I--1-Cllo ~~ -Z =>-5:iE ~o ::l: oo O::l: ZJ: 0 oe:. ::l:U :J :J a. :J c.. Ql :JU) u 105 15 103 12 104 11 107 13 109 14 18 23 i. ~L-----'-1-----'--'--..J....----------,-----------..J....-.1.-.---'---'---L....-.l.---1--------l TEST BORING LOG PLATE 8-7 ~ : L ~ ~ b Cl 0 w ~ 0 "' 2 Cl ~ ~ _, JOB NO.: 07G227 • SOUTHERN CALIFORNIA ,. GEOTE~HNI~~~ • DRILLING DATE: 12/28/07 PROJECT: Bressi PA 3 Lots 10-13 :LOCATION:_ Carlsbad, California DRILLING METHOD: Hollow Stem Auger.- LOGGED BY: Tim Smith FIEL.0 RES UL ts f; I-:i z w w ::::> a. !:!:. 0 w (.) I- J: ...J w Ii: a. ~ ~-~ (.) U.-w ~ ...J ~~ Cl IXl 5 10 15 DESCRIPTION SURFACE ELEVATION: 314 feet MSL . . SANTIAGO FORMATION BEDROCK: Orange to Gray fine grained Sandstone, some Silt, dense to very dense-moist 8\>ring Terminated at 19½' BORING NO. 8-8 WATER DEPTH: Dry CAVE DEPTH: 16 feet READING TAKEN: At Completion LABORATORY RESULTS 14 14 13 17 21 16 ~'---'-......J-"--'---'---L.....;.----------.....;..-----------'----'---'--...1.--__...J'---......... --'------ TEST BORING LOG PLATE 8-8 . ·, .! · . .. POOR . . . . . · · ··QUALITY ' . t 1. k: . r, ~ ~ . · · O·RIGINAL S • I • ~ ;r •· '· - Consolidation/Collapse Test Results 0 ., ---, ~ --.. ~ !'-;, I 1·. I I I I Water Added I 2 I at 1600 psf I 4 4~ ~ .. .. .. .. . . ..... ~ -.. .. .. ... . .. · .. ·. .. l 6 .. . ... I:"\ .. C K .. .. 'f, r ..... .... . . ,~ : . .. .... ' '!'Ii:. i: . ~ • .... . .... .. . . . .. rn .. .. ,'',, !"' ·'·Ni ., ::,;::: .. ' 1,l • ':. C 8 ' .. :-:: ... Iii:, .. · ..... ·: '• 0 . :.:i I', - I'll r'\... ,, ~ -Ill C 0 10 -CJ, '. . . ., ... . . .. · . . . .. . . .. : 12 .. ; .. .. . ' ::: .. _;: .. : .. ., •. ·. . . . .. 14 .. 16 0:1 1 10 100 Load (ksf) Clas~ification: FILL: Brown fine Sand, some Silt, some Shell material Sorin~ Number: 8-3 Initial Moisture Content(%) 8 · Sample Number: ---Final Moisture Content(%) 18 Depth (ft) 1 to 2 Initial Dry Density (pcf) 109.3 Specimen Diameter (in) 2.4 Final Dry Density (pcf) 119.5 Specimen Thickness (in) 1.0 Percent Collapse (%) 2.40 Bressi PA 3 Lots 10-13 ~ SOUTHERN Carlsbad, California CALiFORNIA Project No. 07G227 G'EO°i'EdiNICAL PLATE C-1 ~ .... •' ' .\ :·:~:;,7.;,,;;,, l.1',,'' 1,.n,11, . - Consolidation/Collapse Test Results o. ,L_ -.. . --,~~ •, ·._.,,.,.. ··.· ... , . ' ~; ' •. . . :~ .... ~. ;.-: ·. ~ ,2 --.. · · ~=.;. · · · : ··,i Water Added I ,. ,. · .. :.~·; .·.· ,.''.I at 1600psf .,. '. = •. i, -~~. ·. : I~!'. ~6+-----~--l-~-l-~~+--~-'-+~-+--1--+-1~+-H~-~-+-'-~+-+~~ c ~ Cl) g 8-+-~-'--+---+--+--+--~+-l-+-,-----'--+~-+--+---+-,-J-t-+-+"f~---+--+--+-+-+--1--+-1 ;I l'II :5! 0 en C 8 10 -1--,----,+--+---,-1--1--+-_+', -1-+--+----+..;......c..-+----'+--+--il-+-+-+-l--.,,...·+-:.-----+-,f--+-t .. ·.· 14 -l-----,--+--1--~-l-~..+--+-o-1-'-,--,---'-+--+--l-+-lc...+-+-H--~'+----, __ +-'--+-+-+-'-H .. -:-H __ .. .. '· .. 0:1 10 Load (ksf) Classification: FILL: Brown fine Sand, some Silt, some Shell material Boring Number: Sample Number: Depth (ft) Specimen Diameter (in) Specimen Thickness (in) Bressi PA-3 Lots 10-13 Carlsbad, California Project No. 07G227 PLATE C-2 8-3 3 to 4 2.4 1.0 · Initial' Moisture Content(%) Final Moisture Content(%) Initial Dry Density (pct) Final Dry Density (pct) Percent Collapse (%) 100 18 25 104.9 110.6 0.37 CQnsolidation/Collapse Test Results °୭F=:::.=rTT777Tf--,777111n--,r1,TTTTll-N.__...._ l'--e: : Water Added I 2 +-----l---t---i----l--l-+-l-+-1--._:i:---1~-l-l1 at 1600 psf lf------J--+----1--1-+-++~ ----....i":'-,...,. .•. -: ; :, · 1~-~:k·: ~s~~~--+--~~-+-l-++---+--+~-+~l-H-+-~-~-~~-+-~~ C: ! 88-l-~-+---1---1-~-+-l-++----1-~--+-~~~~--~--l-~~~H i !! 0 ~ 8 10-1-~-+---l--+-'-~-+-l-++-~-+--+--,-f-+-HH-1--l----l-~~--l-l-+--i-+-l .. .. --.. ·,·. .. .. ' ' 14 -l---+--+----1-~-+-l--++----l-'--,---l-~-+~l-H--1----l-~-+---1-~++-l 16 - 0.1 ' Classification: · Boring Numbf3r: Sample Number: Depth (ft) Specimen Diameter (in) Specimen Thickness (in) Bressi PA 3 Lots 10-13 Carlsbad, California Project No. 07G227 -PLATE C-3 B-3 --- 5 to 6 2.4 1.0 1 10 100 l,.Qad (ksf) . BEDROCK: Light Gray Silty Sandstone Initial Moisture Content (%) Final Moisture Content(%) Initial Dry Density (pcf) Final Dry Density (pcf) Percent Collapse(%) 13 19 108.9 116.8 0.45 t •. . ' ' -i L Consolidation/Collapse Test Results °ിF;::::::::.::=-i-:::T77TI1T~7-:-f7rTTTTil--1TTTTTTTl-~k ', ., r--.r-,0;,;.· ! ... , 2 -l----l---l--l--l----J!-1-1-++~. ~-:-. -.. i==.::l:::l--'--iwti:a:'i!te~r A~d~de~d -,.l~+---j-!-4-1-+++-l J. I at 1600psf "' "" 4 +-----+--+--+--1--+-+-+-H--~--'--.!,..,,..._ -1--1-1-+-1-l-+----l---+---+--+--+-+-H-1 .... 14+-----1--+----l---l-l--+-l-H---'--...,+--,--+--1--1----+-'P'·H-J----+-,---!-f--+-f-+,-f--H ~. . ·• ,· :- 0.1 10 Load (ksf) Classification: BEDROCK: Light Gray Silty Sandstone Boring Number: Sample Number: Depth (ft) Specimen Diameter (in) Specimen Thickness (in) Bressi PA 3 Lots 10-13 Carlsbad, California Project No. 07G227 PLATE C-4 B-3 7 to 8 2.4 1.0 Initial Moisture Content(%) Final Moisture Content(%) Initial Dry Density (pcf) Final Dry Density (pcf) Percent Collapse (%) 100 13 19 108.1 117.2 0.62 • . . . I. Consolidation/Collapse Te~t Results 0------'-----~......,....~....-.---...----,..~---.-.....-'-r-'T-,..-..-'----'-..-----,----,..__,_~......,_......, L. . -, ___ ' 2 ..cc· --'---=--+------t~· \-..,_,:· '.-,,,,-' .. :,--~+.,t,+if"· .'1,i;:,, ~---:;_,.:..;:• '·+: ·.:.,.,.::.-'-;.\7.1"/:e...,.:· -+: · ...,_.··.f:·. ·::'::'Iii:-'--: .. : .f-:. 'r-tH_-. _· -:--'-'---'-:-t,---:-.. -:-f.-.. "'7-:'---t.----t-iH:+I I -: ,. • • • '• •~ , , • , ····,;: .· ...... /: Water-Adi:led I. .. :. l'-r-"'T"a-,t 1_eor-o,-,psr-rf __,lf'-c-. ---+-c,-'--;-.,--+---,1-+--,-1-'-1-+-l _··,;: \" :,: ... 4 +--,----+---+---+--+-+-+-c+.+-t---,----+-. ,*-".: --'-f-.. + .. -. -+: •• ~-+. -'t: -. t-t,-1: H .. ------'-~--t--+---1-'-+-+--t-1--H ·.: .. ·-· .. • .·"',. . • -=-: -• • .-:: • •. ··~ ,.,· •• --:. :··. ·'· • •• ,: ~-. • • •• •· ' • '. • • .. 1~ +----'-+--t---+--i-t-·t-~:+~-+-~-~:+·~·P.:i.:~-~·-..-·M:..,.,.-;:+·;_~··:....,.· "1-~_.~,~~~--?:..,... -"-'l~~:,:1---·'....,.~Hi."'""f ._, .. _. _· -~-?:;-:·..,..., _·:·+·:_·~-.-+-: -...,.~:-r-.. :-+. ,-'-1·.~H~·r+.-t,-. . ·.:. :·.-:···::-:: __ '.::;)/:-.':-.. ( ,<:::-}:;.: ;: . _.::·-.::'-\ ··'.: ·<·. ,.:.· ::: .::.:.·. • H• • .·: .. ·.. . .. · ..... ···· .-·· · .. ·-:.-:. • ·,. :· ·1_. : ;' 14 +--~--+--t---+--+-i-,-+--t-+-1-'-~---+---r.--+" _ .. +' --t-t,-t-H'---,-,-;--+---;--+-+-+-1-H 0.1 10 · ·Load (ksf) Classification: FILL: Brown fine Sand, some Silt Boring Number: Sample Number: Depth (ft) Specimen Diameter (in) Specimen Thickness (in) Bressi PA 3 lots 10-13 Carlsbad, California Project No. 076227 PLATE C-5 8-5 1 to 2 2.4 1.0 Initial Moisture Content(%) Final Moisture Content (%) Initial Dry Density (pcf) Final Dry Density (pcf) Percent Collapse (%) 100 9 17 104.2 117.3 3.04 Consolidation/Collapse Test Results 0 ',' .. """-1 --... I • • ~ . ": ', r,~ I I 1•··1, .. ,, ------.. I Water Added I 2 I at 1600 psf I -.... ~ 4 ~ .. ..... . , . ,,• ~ ~-··. -6 ·, ... :,e ' ..... 0 -. : ' •, i:: -~-~ ... .. :• N; .. ... . . .. .. .. . · · . .:, ·-::N ·.,· .. ··-·: .-:, \_;~): ·· .. ,. ., .:• 1,:·: :,;:~:~\ •i,,• "' ... .. ... l ~(-<·> ·,·,· .::·\ r:?:. C .. : ' ., .. i.-:., ~-· . : ' ·;·,,· '• :(_ :: MO ,:_!iJ '/:::. 0 8 ·. . .. . . , •:,::~:··.·. . '•• .. '•. ~· = '• . ' CV :2 0 .. ·. C/1 .. ,' C ·· .. 0 10 .. (J .. : .. .··:·. ". 12 ., 14 . I' " '• 16 .. 0.1 1 10 100 Load (ksf) Classification: BEDROCK: Brown Gray Sandstone '. Boring Number:·· 8-5 Initial Moisture Content(%) 8 Sample Number: ---Final Moisture Content(%) 22 Depth .(ft) 3 to 4 Initial Dry Density (pcf)-105.3 Specimen Diameter (in) 2.4 Final Dry Density (pcf) 111.1 Specimen Thickness (in) 1.0 Percent Collapse (%) 1.20 ... Bressi PA3 Lots 10-13 ~ __ cf~gg:~ Carlsbad, California Project No, 07G227 ... GEOTECHNICAL PLATE ~-6 ------· • -·--·,.\·, ·,11i{o111111 crr;;;;u;:·:;;,: '. Consolidation/Collapse Test Results ---.L.. --N~-..,~ 2 t---t-+++H--J+P .... ..,-iiii.~::;:::::±:!1w°Maallteir"r AAcdia;de~d11r+~t--t-H-H-H .I at 1600 psf . , .. :· ·: ' .. :. .. ~ '. •,·· :· •, . ·,· • • • . • : .;, .... _., i •• · • •. • •. :· -r __ .:_;:;_" • ' •' :? i I •, • ' ' • • • • ,,.~ •,• • ; ,:•; -. ~I ·~ • ' 12 -i-------i---;-,---..i---+-t-1---r-t-f-----.+----M--t-,-+o-t-..,,.,.t-t:--,H---,--t-"---t-,-----t-'-~ .. i'-t'-t-t .... -H 16 +-',----'----'-'--'--'----'--'--'--'-1---...,______._--'---"'___.__._.__.__ ___ ,____.__,___,_........_.-'-'-l 0.1 Classification: Boring Number: Sample Number: Depth (ft) Specimen Diameter (in) Specimen Thickness. (in~ Bressi PA 3 Lots 10-13 Carlsbao, California Pr-oject No. 07G227 PLATE C-7 B~s --- 5 to 6 2.4 1.0 10 100 Load (ksf) aEDROCK: Brown Gray Sandstone Initial Moisture Content(%) Final Moisture Content(%) Initial Dry Density (pcf) Final Dry Density (pcf) Percent Collapse (%) 15 28 97.3 107.4 1.47 Consolidation/Collapse Test Results 0 ------~ "-'--- "'11. --~: I Water Added I 2 ------. I at 1600 psf I ............ • ..... , ' 4' 1-. r-.., -6 ""-~ C 'j! ... "' C 8 0 i' 3i! ,o .,, C 8 10 12 14 16 0.1 1 10 100 Load (ksf) - Classification: BEOROCK: Gray fine Sandy Siltstone Boring Number: B-5 Initial Moisture Content(%) 18 Sample Number: ---Final Moisture Content(%) 21 Depth (ft) 7 to 8 Initial Dry Density (pcf} 102.9 Specimen Diameter (in) 2.4 Final Dry Density (pcf) 108.8 Specimen Thickness (in) 1.0 Percent Collapse(%) 0.14 ' - Bressi PA 3 Lots 10-13 ~GEJ;E~t\1!~ Carlsbad; California Project No. 07G227 .PLATE C-8 ... ' ~·.i,··.·11!1•1•,,11i·,,ry•:•1,;,•:11, l: L • i" . ., ., .. POOR . · .QUALITY· . j-. f. ! ~ . r, .;, ! . · · O·RIGINAL . S . :~~ . I • I • I '. '. Grading Guide Specifications Page 1 GRADING GUIDE SPECIFICATIONS These grading guide specifications are intended to provide typical procedures for grading operations. They are intended to supplement the recommendations contained in the geotechnical investigation report for this project. Should the recommendations in the geotechnical investigation report conflict with the grading guide specifications, the more site specific recommendations in the geotechnical investigation report will govern. General • The Earthwork Contractor is responsible for the satisfactory completion of all earthwork in accordance with the plans and geotechnical reports, and in accordance with city, county, and -Uniform Building Codes. • The Geotechnical Engineer is the representative of the Owner/Builder for the purpose of implementing the report recommendations and-guidelines. These duties are not intended to relieve the-Earthwork Contractor of any responsibility to perform in a workman-like manner, nor is the Geotechnical Engineer to direct the.grading equipment or personnel employed by the Contractor. • The Earthwork Contractor is required to notify the Geotechnical Engineer of the anticipated work and s<;:hedul~-so that testing and inspections can be provided. If-necessary, work may be stopped and redone if personnel have not been scheduled in advance. • The Earthwork Contractor is required to have suitable and sufficient equipment on the job- site to process, moisture condition, mix and compact the amount of fill being placed to the approved compaction. In addition, suitable support equipment should be available to conform with recommendations and guidelines in this report. • Canyon cleanouts, overexcavation areas, processed ground to receive fill, key excavations, subdrains and benches should be observed by the Geotechnical Engineer prior to placement of any fill. It is the-Earthwork Contractor's responsibility to notify the Geotechnical Engineer of areas that are ready for inspection. • Excavation, filling, and subgrade preparation should be· performed in a manner and sequence that w,ill provide drainage at all times and proper control of erosion. Precipitation, springs, and seepage water encountered shall be pumped or drained to provide a suitable working surface. The Geotechnical Engineer,must be informed of springs or water seepage encountered during grading or foundation construction for possible revision to the recommended construction procedures and/or installation of subdrains. Site Preparation • The Earthwork Contractor is responsible for all clearing, grubbing, stripping and site preparation for the project in ·accordance with the recommendations of the Geotechnical Engineer: • lfany materials or areas are encountered by the Earthwork Contractor which are suspected of having toxic or environmentally sensitive contamination, the Geotechnical Engineer and Owner/Builder shoulcl be notified immediately. • Major vegeti;ition should be stripped and disposed of off-site. This includes trees, brush, heavy grasses and any materials considered unsuitc!ble by the Geotechnical Engineer. .. i t. Grading Guide Specifications Page2 • Underground structures such as basements, cesspools or septic disposal systems, mining shafts, tunnels, wells and pipelines should· be removed under the inspection of the Geotechnical Engineer and recommendations provided by the Geotechnical Engineer and/or · city, county or state agencies. If such structures are known or found, the Geotechnical Engineer should be notified as soon as possible so that recommendations can be formulated. • Any topsoil, slopewash, colluviuni, alluvium and rock materials which are considered unsuitable by the Geotechnical Engineer should be removed prior to fill placement. • Remaining voids created during site clearing caused by removal of trees, foundations basements, irrigation facilities, etc., should be excavated and filled with compacted fill. • Subsequent to clearing and removals, areas to receive fill should be scarified to a depth of 10 to 12 inches, moisture conditioned and compacted • The moisture condition of the processed ground.should be at or slightly above the optimum moisture content as determined by the Geotechnical Engineer. Depending upon field conditions, this may require air drying or watering together with mixing and/or discing. Compacted Fills • Soil materials imported to or excavated oh the property may be utilized in the fill, provided each material has been determined to be suitable in the opinion of the Geotechnical Engineer. Unless otherwise approved by theGeotechnical Engineer, all fill materials shall be free of deleterious, organic, or frozen matter, shall contain no chemicals that may result in the material being classified as "9ontaminated," and shall be very low to non-expansive with a maximum expansion index (~l)of 50. The top 12 inches of the compacted fill should have a maximum particle size of 3 inches, and all underlying compacted fill material a maximum 6-inch particle size, except as noted below. • All soils should be evaluated and tested by the Geotechnical Engineer. Materials with high expansion potential, low strength, poor gradation orcoritaining organic materials may require removal from the site or .selective placement and/or mixing to the satisfaction of the Geotechnical Engineer. • Rock fragments or -rocks less than 6 inches in their largest dimensions, or as otherwise determined by the Geotechnical Engineer, may be used in compacted fill, provided the distribution and placement is satisfactory in the opinion of the Geotechnical Engineer. • Rock fragments or rocks greater than 6 inches should be taken off-site or placed in accordancewith recommendations and in areas designated as suitable by the Geotechnical Engineer. Acceptable methods typically include windrows. Oversize materials should not be placed within the range of excavation for foundations, utilities, or pools to facilitate excavations. Rock placement should.be kept away from slopes (minimum distance: 15 feet) to facilitate compaction near the slope. • Fill materials approved by the Geotechnical Engineer should be placed in areas previously prepared to receive fill and in evenly placed, near horizontal layers at about 6 to 8 inches in loose thickness, or as otherwise determined by the Geotechnical Engineer for the project. • Each layer should be moisture conditioned to optimum moisture content, or slightly above, as qirected by the Geotechnical Engineer. After proper mixing and/or drying, to evenly distribute the moisture, the iayers should be compacted to at least 90 percent of the maximum dry density in compliance with ASTM D-1557-78 unless otherwise indicated. '· Grading Guide Specifications Page 3 • Density and moisture content testing should,be performed by the Geotechnical Engineer at random intervals and locations as determined by the Geotechnical Engineer. These tests .are intended as an aid to the Earthwork Contractor, so he can evaluate his workmanship, equipment effectiveness and site conditions. The Earthwork Contractor is responsible for compaction as requireq by the Geotechnical Report(s) and governmental agencies. • Fill areas unused for a period of time may require moisture conditioning, processing and recompaction prior to th~ start of additional filling. The Earthwork Contractor should notify the Geotechnical Engineer of his intent so that an evaluation can be made. • Fill placed-on ground sloping at a 5-to-1 inclination (horizontal-to-vertical) or steeper should be benched into bedrock -or other suitable materials, as directed by the Geotechnical Engineer. Typical details of benching are Hlustrated on Plates G-2, G-4, and G-5. • CuVfill transition lots should have the cut portion overexcavated to a depth of at least 3 feet and rebuilt with fill (see Plate G-1), as determined by the Geotechnical Engineer. • All cut lots should be inspected by the Geotechnical Engineer for fracturing and other bedrock conditions. If necessary, the pads should be overexcavated to a depth of 3 feet and rebuilt with a uniform, more cohesive soil. type to impede moisture penetration. • Cut portions of pad areas above buttresses or stabilizations should be overexcavated to a depth of 3 feet and rebuilt with uniform, more cohesive compacted fill to impede moisture penetration. • Non-structural ,fill adjacent to structural fill should typically be placed in unison to provide lateral support. Backfill along walls must be placed and compacted with care to ensure that excessive unbalanced lateral pressures do not develop. The type of fill material placed adjacent to below grade walls must be properly tested arid approved by the Geotechnical Engineer with consideration of the lateral earth pressure used in the design. Foundations • The foundation influence zone is defined·as extending one foot horizontally from the outside edge of a footing, and.proceeding downward at a½ horizontal to 1 vertical (0.5:1) inclination. • Where overexcavation ben_eath a footing subgrade is necessary, it should be conducted so as to-encompass the entire foundation influence zone, as described above. • Compacted fill adjacent to exterior footings should extend ;:it least 12 inches above foundation bearing grade. Compacted fill within the interior of structures should extend to the floor subgrade elevation. Fill Slopes • The placement and compaction of fill described above applies to all fill slopes. Slope compaction should be acGomplished by overfilling the slope, adequately compacting the fill in even layers, including the overfilled zone and cutting the slope back to expose the compacted core • Slope compaction may also be achieved by backrolling the slope adequately every 2 to 4 vertical feet during the filling process as well as requiring the earth moving and compaction equipment to work close to the top of the slope. tJpon completion of slope construction, the slope face-should be compacted with a sheepsfoot connected to a sideboom and then grid rolled. This method of slope compaction should only be used if approved by the Geotechnical Engineer. •· 1 ' Grading Guide Specifications Page4 • Sandy soils lacking in adequate cohesion may be unstable for a finished slope condition and therefore should not be placed within 15 .horizontal. feet of the slope face. • All fill slopes should be keyed into bedrock or other suitable material. Fill keys should be at least 15 feet wide and inclined at 2 _percent into. the slope. For slopes higher than 30 feet, · ·the fill key width $hould be equal to one-h~lf the heigt,t of the slope (see Plate G-5). • All fill keys should be cleared of loose slough material prior to geotechnical inspection and should be approved by the Geotechnical Engineer and governmental agencies prior to filling. • The cut portion of fill over cut slopes should be made first and inspected by the Geotechnical Engineer for possible stabilization requirements. The fill portion should be adequately keyed through all surficial soils and into bedrock or suitable material. Soils should be removed from the transition zone between the cut and fill portions (see Plate G-2). Cut Slopes • All cut slopes should be inspected by the Geotechnical Engineer to determine the need for stabilization. The Earthwork Contractor should notify the Geotechnical Engineer when slope cutting is in progress at intervals of 1 O vertical·feet. Failure to notify may result in a delay in recommendations. • Cut slopes exposing loose, cohesionless sands should be reported to the Geotechnical Engineer for possible stabilization .recommendations. • All stabilization excavations should be cleared of loose slough material prior to geotechnical inspection. Stakes should be provided by the Civil Engineer to verify the location and dimensions of the key. A typical stabilization fill detail is shown on Plate G-5. • Stabilization key excavations should be provided with subdrains. Typical subdrain details are shown on Plates G-6. Subdrains • Subdrains may be required in canyons and swales where fill placement is proposed. Typical subdrain details for canyons are shown on Plate G-3. Subdrains should be installed after approval of removals and before filling, as determined by the Soils Engineer. • Plastic pipe may be used for subdrains provided it is Schedule 40 or SOR 35 or equivalent. Pipe should be protected against breakage, typically by placement in a square-cut (backhoe) trench or as recommended by the manufacturer. • Filter material fot subdrains should conform to CAL TRANS Specification 68-1. 025 or as approved by the Geotechnical Engineer for the .specific site conditions. Clean ¾-inch crushed rock may be used provided it is wrapped in an acceptable filter cloth and approved by the Geotechnical Engineer. Pipe diameters should be 6 inches for runs up to 500 feet and 8 inches for the downstream continuations of longer runs. Four-inch diameter pipe may be used in buttress and $tabilization fills. : ! -. I . I J . I I ~I • I j I ' I - . , . .. - : .. ···.· -·~·,;...-·: .. · . ...,..:--. . ' _.--;· _; •. :: . : .:: -. ..... ·\ ... ----- CUT LOT OVEREXQAVATE AND RECOMPACT COMPETENT MATERIAL, AS APPROVED BY THE GEOT!':CHNICAL ENGINEER CUT/FILL LOT (TRANSITION) COMPETENT MATERIAL, AS APPROVED BY THE GEOTECHNICA~ ENGINEER -- 3'MIN. f -----------.,,. .,,. TRANSITION LOT DETAIL GRAPING GUIDE SPECIFICATIONS NOTTO SCALE DRAWN: JAS CHKO: GKM PLATE D-1 • SOUTHERN CALIFORNIA ~ GEOTECHNICAL : j . fa, _________ ..., _______________ .._ ____________________ _. j .. ~ ' - l.. COMPETENT MATERIAL CUT/FILL CONTACT TO BE SHOWN ON "AS-BUILT" NATIJRAL GRADE ~ -- CUT SLOPE TO BE CONSTRUCTED PRIOR TO PLACEMENT OF FILL . MAXIMUM HEIGHT OF BENCHES IS 4 FEET OR AS RECOMMENDED . BY THE GEOTECHNICAL ENGINEER L MINIMUM 1' TILT BACK OR'2%SLOPE (WHICHEVER IS GREATER) BEDROCK OR.APPROVED COMPETENT MATERIAL KEYWAY IN COMPETENH;lATERIAL MINIMUM WIDTH OF 15 FEETORAS RECOMMENDED BY THE GEOTECHNICAL ENGINEER. KEYWAY MAY NOTBE REQUIRED IF FILL SLOPE IS LESS THAN 5 FEET IN HEIGHT AS RECOMMENDED BY THE GEOTECHNICAL ENGINEER. FILL ABOVE CUT SLOPE DETAIL GRADING GUIDE SPECIFICATIONS NQTTOSCAtE DRAWN: JAS <:;HKD: GKM PLATED-2 ~ SOUTHERN · ,_,.-CALIFORNIA ,,• GEOTECHNICAL 'L· ' , ' '' -' . ' .... . . ~~TU~A~~~QUN~1·· .. · .. : ... ( ... ·_. ·.· . . . . . . , > ., . . . ·: .. :. . . :_ .. ·· ........ •, /_, .. . ... 'L!! ,· .. :to, ~;~~;~D_·.,;;~~ /_·. :. · . · .. , . : ... · ... · .. : . ·J l: : ~~ ·: : ·, :_'y ·,· .-~ . /".· .... · .. : .·,;·::·. ~-·--:.· . . ·. . . . ·. .. ' . . . . ·. •. ~: ~-:> .. /dLEAN.OUT.EXCA~ATl6~· · · .:··. ~-.··. 6"~!N, .. · .·: .. ,,;.:~;'.-~r·· .. ··. ~r,<;J'=~~r---1 -.:.~.;; .-':.: ·,: · ·.'· .. .. · · ~ .... .:·.: .. ~-.. -~~-,_ =-4' I '/1-::::-,,"-~,,. '/I; FIRM NATIVE SOIL/BEDROCK • . C ,. :• .,;, ~ _: _.4: . .: :":~··.< \~ ...... '.,· 24" MIN. : .. ··" ····· :d-~ 18 L. MIN. .,0f3.i ·L· ;. • · .. ; ·:: i.· ,-"'MINUS 1• CRUSHED ROCK coMPLETEL v · ~-" · ~· SURROUNDED BY FILTER FABRIC, OR ." .. ·• . . '· / ~ .. .4 .. " CLASS II PERMEABLE MATERIAL . . ~. . . . . ~18'MIN~ 4"MIN. 6" DIAMETER PERFORATED PIPE -MINIMUM 1% SLOPE PIPE DEPTH OF fill MATERl~L OVER SUBDRAIN ADS (CORRUGATED-POLETHYLENE) 8 TRANSITE UNDERDRAIN 20 PVC CRABS: SOR 35 35 SOR 21 100 SCHEMATIC ONLY NOTTO SCALE CANYON SUBDRAIN DETAIL GRADING GUIDE SPECIFICATIONS NOTTO SCALE DRAWN: JAS CHKD: Gf<M PLATE 0-3 • SOUTHERN CALIFORNIA ,, GEOTECHNICAL . , FINISHED SLOPE FACE · -- c . • I .. I ; ' NOTE: BENCHING SHALL BE REQUIRED WHEN NATURAL SLOPES ARE EQUAL TO OR STEEPER THAN 5:1 OR WHEN RECOMMENDED BY THE GEOTECHNICAL ENGINEER. FILL ABOVE NATURAL SLOPE DETAIL GRADING GUIDE SPECIFICATIONS NOTTOSCAlE DRAWN: JAS' CHKD: 13KM .PLATE D-4 ~ SOUTHERN ,..,. CALIFORNIA ...,• GEOTECHNICAL , ' '. l. ........ ' . ':··_··_:<:··-~, '.: ::_-~} <::::.:·:·:\ _J_ . 3' lYl?ICAL BLANKET FILL IF RECOMMENDED BY THE GEOTECHNICAL ENGINEER TOP WIDTH OF FILL AS SPECIFIED BY THE GEOTECHNICAL ENGINEER VARIABLE MINIMUM HEIGHT OF BENCHES IS 4 FEET OR AS RECOMMENDED BY THE GEOTECHNICAL ENGINEER . J-·1 · ··. LM;NIMUM1'TILTBACK 2' MJeJM"M , , .I OR 2% SLOPE KEY DEPTH KEYWAY WIDTH, AS SPECIFiED (WHICHEVER IS GREATER) BY THE GEOTECHNICAL ENGINEER STABILIZATION FILL DETAIL GRADING Gl/lDE.SPEClflCATIONS NOTTO SCALE DRAWN: .JAS .. CHKD: GKM PLATE D·5 • . . . SOUTHERN CALIFORNIA ... GEOTECHNICAL . ' '' . ' DESIGN FINISH SLOPE OUTLETS TO BE SPACED AT 100' MAXIMUM INTERVALS. · EXTEND 12 INCHES BEYOND FACE OF SLOPE AT TIME OF ROUGH GRADING CONSTRUCTION. BUTTRESS OR SIDEHILL FILL ~ 15' MAX. ., ·.·.·: , ... ' .· .. 2'CLEAR • .. ,: BLANKET FILL IF RECOMMENDED BY THE GEOTECHNICAL ENGINEER DETAIL "A" \_ 4-INCH DIAMETER NON-PERFORATED OUTLET PIPE TO BE LOCATED IN FIELD BY THE SOIL ENGINEER. "FILTER MATERIAL" TO MEET FOLLOWING SPECIFICATION "GRAVEL" TO MEET FOLLOWING SPECIFICATION OR APPROVED EQUIVALENT: OR APPROVED EQUIVALENT: (CONFORMS TO EMA STD.PLAN 323) SIEVE SIZE 1" PERCENTAGE PASSING 3/4" 3/8" NO.4 No.a NO.30 NO. 50 NO. 200 OUTLET PIPE TO.BE CON- NECTED TO SUBDRAIN PIPE 1· . WITH TEE OR ELBOW 100 90-100 40-100 25-40 18-33 . 5-15 0-7 0-3 .---------1 ,_---;--. MAXIMUM SIEVE SIZE PERCENTAGE PASSING 11/2" 100 NO. 4 50 NO. 200 8 SAND EQUIVALENT= MINIMUM OF 50 FILTER MATERIAL -MINIMUM OF FIVE CUBIC FEET PER FOOT OF PIPE. SEE . ABOVE FOR FILTER MATERIAL SPECIFICATION. ALTERNATIVE: IN LIEV OF FILTER MATERIAL FIVE CUBIC FEET OF GRAVEL PER FOOT OF PIPE MAY'BE ENCASED IN FILTER FABRIC. SEE ABOVE FOR GRAVEL SPECIFICATION. FILTER FABRIC SHALL BE MIRAFI 140 OR EQUIVALENT. FILTER FABRIC SHALL BE LAPPED A MINIMUM OF 12 INCHES ON ALL JOINTS. ~ MINIMUM 4-INCH DIAMETER PVC SC~, 40 OR ABS CLASS SOR 35 Willi DETAIL "A" NOTES: 1. TRENCH FOR OUTLET P-IPES TO BE BACKFILLED WITH ON-SITE SOIL. A CRUSHING STRENGTH OF AT LEAST 1,0Q0 POUNDS, WITH A MINIMUM OF 8 UNIFORMLY SPACED PERFORATIONS PER FOOT OF PIPE INSTALLED WITH PERFORATIONS ON BOTTOM OF PIPE. PROVIDE CAP AT UPSTREAM END OF PIPE. SLOPE AT 2 PERCENT TO OUTLET PIPE. SLOPE FILL SUBDRAINS GRADING GUIDE SPECIFICATIONS NOTTO SCALE DRAWN: JAS CHK0: GKM PLATE D-6 ..... -------------------------------------------------- MINIMUM ONE FOOT THICK LAYER OP MINIMUM ONE FOOT WIDE LAYER OF LOW PERMEABLILITY SOIL IF NOT FREE DRAINING MATERIAL COVERED WITH AN IMPERMEABLE ~RFA\ / (LESS THAN 5% PASSING THE #200 SIEVEi q '/ . ... _.FILTER MATERIAL· MINIMUM OF TWO CUBIC FEET PER FOOT OF PIPE. SEE BELOW FOR FILTER MATERIAL SPECIFICATION . ALTERNATIVE: IN LIEU OF FILTER MATERIAL TWO CUBIC FEET OF GRAVEL PER FOOT OF PIPE MAY BE ENCASED IN FILTER FABRIC. SEE BELOW FOR GRAVEL SPECIFICATION. FILTER FABRIC SHALL BE MIRAFI 140 OR EQUIVALENT. FILTER FABRIC SHALL BE LAPPED A MINIMUM OF 6 INCHES ._ON ALL JOINTS. ".':;~; 0\·~·.'.:?·?;·~0-(r-MINIMUM 4-INCH DIAMETER ,PVC SCH 40 OR ABS CLASS SOR 35 WITH ,;~./··'05···:·., :.·<·~-< A CRUSHING STRENGTH OF AT LEAST 1,000 POUNDS, WITH A MINIMUM :·:... ···, '· · OF 8 UNIFORMLY SPACED PERFORATIONS PER FOOT OF PIPE INSTALLED : "!:· . ':'.·i WITH PERFORATIONS ON BOTTOM OF PIPE. PROVIDE CAP AT UPSTREAM ,~;:-., . ,;'°:;:_:: END OF PIPE. SLOPE AT 2 PERCENT TO OUTLET PIPE. ~ ... ~-,. ·::., :··: .. ·r;··. ·q q . .cl 4 4 ~ .. 4 . ·4 q. 4 . ·- "FILTER MATERIAL" TO MEET FOLLOWING SPECIFICATION "GRAVEL" TO MEET FOLLOWING SPECIFICATION OR APPROVED EQUIVALENT: OR APPROVED EQUIVALENT: (CONFORMS TO EMA STD. PLAN 323) SIEVE SIZE 1'' 3/4" 3/8" NO.4 NO.8 NO.30 NO.50 NO. 200 PERCENTAGE PASSING 100 90-100 40-100 25-40 18-33 5-15 0-7 0-3 MAXIMUM SIEVE SIZE PERCENTAGE PASSING 1 1/2" 100 NO.4 50 NO. 200 8 SAND EQUIVALENT= MINIMUM OF 50 RETAINING WALL BACKDRAINS GRADING GUIDE SPECIFICATIONS NOTTO SCALE DRAWN: JAS CHKD: GKM PLATE0-7 • SOUTHERN CALIFORNIA ,, GEOTECHNICAL .,, • ' '. • •••• •• : • l • •• •• • • • .~,.... • • ' • • •• ' --:·i • . . . ··.. . ' ~ --) . ' ,· . ' .. .. ' ' .. · POOR QUALITY t"; ;-: , r, ' l . · ORIGINAL S b.80 0.75 I ! I ! 0.70; I f 0.65! I 0.60 · I i o.55 : ; ~ :::: :;' 0) -' ~ ' ~ 0.40; ·1 0.35 i I 0.30 0.25 0.20 0.15 0.10 0.05 De_J~gn~Spectruro Sa Vs T ... ...__ ,..........._ '---....__ ---------·-----------------~ ·-- 0.00-.. · · · .... · ... .. ·--·---· · .. · · ... -.. o 0.1 0.2 o.3 o.4 o.5 o.6 0.1 o.B o.9 1-1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.a 1.9 2 2.1 T (sec) ,, Conterminous 48 States 2006 International Building Code Latitude = 33.12732 Longitude;:: -117.26537 Spectral Response Accelerations Ss and S1 Ss and S1 = Mapped Spe"ctral Acceleration Values Site Class B -Fa = 1.0 ,Fv = 1.0 Data are based on a 0.01 deg grid spacing Period Sa (sec) (g) 0.2 1.131 (Ss, Site Class B) 1.0 0.428 (St, Site Class B) Conterminous 48 States 2000 International Building Code Latitude = 33.12732 Longitude= -117.26537 Spectral Response Accelerations SMs and SM1 SMs = Fass and SM1 = FvS1 Site Class D -Fa= 1.048 ,Fv = 1.572 Period Sa (sec) (g) 0.2 1.185 (SMs, Site Class D) 1.D 0.673 (SM1, Site,Class D) Conterminous 48 States 2006 International Building Code Latitude = 33. 12732 Longitude= -117,26537 SDs .= 2/3 x SMs and SD1 = 2/3 x SM1 -Site Class D -Fa= 1.048 ,Fv = 1.572 Period Sa (sec) (g) 0.2 0.790 (SDs, Site Class D) 1.0 0.449 (SD1, Site Class D) Conterminous 48 States UCEliVE1U'1 AUG 19 2014 LANU Ut:Vt:LUFIVlt:.l\l, ENGINEERJi\ln /