Loading...
HomeMy WebLinkAbout_2025-02-19-05B GeoTechnical Report (GeoSolutions #SL07509-10)_v1 (1)ORCUTT EXPANSION AREA SPECIFIC PLAN INCLUDING APN: 004-705-008; 004-706-002, 006, -007, -008, AND -009; 004-707-001; AND 053-061-024 SAN LUIS OBISPO CITY AND COUNTY, CALIFORNIA PROJECT SL07509-10 IM Prepared for Ambient Communities=; Attn: Rob Horner and Travis Fuentez " 979 Osos Street, Suite E San Luis Obispo, California 93401 Prepared by GEOSOLUTIONS, INC. _ 220 HIGH STREET 7 SAN LUIS OBISPO, CALIFORNIA 93401 (805) 543-8539 January 8, 2019 1021 Weft Tarn Lane, Suite 10-�, Santa %Lti-ia.. CA 9 4� 4 (SWS )614.6 > >, (805 )6.14-6 , : fay SBin lb!Q' 7eosointlotis.l.1%t Ambient Communities Attn: Rob Horner and Travis Fuentez 979 Osos Street, Suite E San Luis Obispo, California 93401 Subject: Soils Engineering Report Update GeoSolutions, mc. '0 1ligh Street, San LLlis Obis po. CA 93)401 (e0; )i4 -2171 fax iniorCr: L1eoSolutiotlS.net January 8, 2019 Project No. SL07509-10 Orcutt Area Expansion Specific Plan Including APN: 004-705-008; 004-706-002, 006, -007, -008, and -009; 004-707-001; and 053-061-024 San Luis Obispo City and County, California References: Soils Engineering Report Update, Orcutt Area Expansion Specific Plan, Including APN: 004-705-008; 004-706-002, 006, -007, -008, and -009; 004-707-001; and 053-061-024, San Luis Obispo City and County, California, by GeoSolutions, Inc., Project No. SL07509-8, dated August 30, 2016. Soils Engineering Report Update, Orcutt Expansion Area Specific Plan — Including APN: 004-705-008, 004-706-002 San Luis Obispo City and County, California, by GeoSolutions, Inc., Project No. SL07509-6, dated October 30, 2015. Soils Engineering Report, Orcutt Expansion Area Specific Plan — Jones Parcel (044-705- 008) San Luis Obispo Area, San Luis Obispo City and County, California, by GeoSolutions, Inc., Project No. SL07509-3, dated May 1, 2014. Dear Mr. Horner and Mr. Fuentez: This Soils Engineering Report Update has been prepared for the proposed "Orcutt Expansion Area Specific Plan" project which is bound by Orcutt Road on the North and East, Tank Farm Road on the South and the Union Pacific Railroad on the West, and includes APN: 004-705-008; 004-706-002, 006, -007, -008, and -009; 004-707-001; and 053-061-024, which is located within both the city of San Luis Obispo and the San Luis Obispo area of San Luis Obispo County, California. Geotechnically, the site is suitable for the proposed development provided the recommendations in this report for site preparation, earthwork, foundations, slabs, retaining walls, and pavement sections are incorporated into the design. It is anticipated that graded pads will be constructed for the proposed development and that foundations will be excavated into engineered fill. All foundations are to be excavated into uniform material to limit the potential for distress of the foundation systems due to differential settlement. If cuts steeper than allowed by State of California Construction Safety Orders for "Excavations, Trenches, Earthwork" are proposed, a numerical slope stability analysis may be necessary for temporary construction slopes. Orcutt Expansion Area Specific Plan January 8. 2019 Proiect SL07509-10 Natural seepage at the interface of two materials with different densities is very common. This interface occurs at the Site and will require sub -surface drains. Sub -drains should be placed in established drainage courses, potential seepage areas, and during the development of all key and bench grading operations. Thank you for the opportunity to have been of service in preparing this report. If you have any questions or require additional assistance, please feel free to contact the undersigned at (805) 543-8539. Sincerely, GeoSo , NO. CA�4 re0TWIMhUM, lNc. Orcutt Expansion Area Specific Plan January 8, 2019 Project SL07509-10 TABLE OF CONTENTS 1.0 INTRODUCTION............................................................................................................................ I 1.1 Site Description................................................................................................................... I 1.2 Project Description..............................................................................................................2 2.0 PURPOSE AND SCOPE.................................................................................................................2 3.0 FIELD AND LABORATORY INVESTIGATION.........................................................................3 4.0 HYDROLOGIC SOIL GROUP........................................................................................................8 5.0 SEISMIC DESIGN CONSIDERATIONS.......................................................................................8 6.0 LIQUEFACTION HAZARD ASSESSMENT.................................................................................9 7.0 GENERAL SOIL -FOUNDATION DISCUSSION..........................................................................9 8.0 CONCLUSIONS AND RECOMMENDATIONS.........................................................................10 7.1 Preparation of Building Pads.............................................................................................10 7.2 Preparation of Paved Areas................................................................................................12 7.3 Pavement Design...............................................................................................................12 7.4 Conventional Foundations.................................................................................................13 7.5 Mat Foundations................................................................................................................15 7.6 Post -Tensioned Slabs.........................................................................................................15 7.7 Slab -On -Grade Construction.............................................................................................16 7.8 Exterior Concrete Flatwork................................................................................................18 7.9 Temporary Slope Stability.................................................................................................18 7.10 Retaining Walls.................................................................................................................19 7.11 Bridge Abutments..............................................................................................................22 9.0 ADDITIONAL GEOTECHNICAL SERVICES............................................................................22 10.0 LIMITATIONS AND UNIFORMITY OF CONDITIONS............................................................23 REFERENCES APPENDIX A Field Investigation Soil Classification Chart Boring Logs Trench Logs 4 Geo5u1utians,iw. Orcutt Expansion Area Specific Plan January 8.2019 Protect SL07509-10 APPENDIX B Laboratory Testing Soil Test Reports APPENDIX C Seismic Hazard Analysis Design Map Summary (SEAOC, 2018) APPENDIX D Preliminary Grading Specifications Key and Bench with Backdrain LIST OF FIGURE Figure1: Site Location Map..........................................................................................................................1 Figure2: Site Plan.........................................................................................................................................3 Figure3: Google Earth Image........................................................................................................................5 Figure 4: Regional Geologic Map..................................................................................................................6 Figure5: Sub -Slab Detail............................................................................................................................12 Figure 6: Setback Dimensions — Slope Gradients Between 3-to-1 and 1-to-1............................................15 Figure7: Retaining Wall Detail...................................................................................................................19 Figure 8: Retaining Wall Active and Passive Wedges.................................................................................20 LIST OF"=1='ABLE.S Table1: Engineering Properties.....................................................................................................................6 Table 2: Seismic Design Parameters..............................................................................................................9 Table 3: Minimum Footing and Grade Beam Dimensions (Expansive Native Soils)..................................13 Table 4: Minimum Footing and Grade Beam Dimensions (24 inches of Non -Expansive) ..........................14 Table 5: Post Tension Foundation Design Criteria......................................................................................16 Table 6: Minimum Slab Recommendations — Expansive Native Soil.........................................................16 Table 7: Minimum Slab Recommendations — Non -Expansive Import .........................................................17 Table 8: Retaining Wall Design Parameters................................................................................................19 Table 9: Required Verification and Inspections of Soils..............................................................................23 5 ffdMMffCdUU==, INC. SOILS ENGINEERING REPORT UPDATE ORCUTT EXPANSION AREA SPECIFIC PLAN INCLUDING APN: 004-705-008; 004-706-002, 006, -007, -008, AND -009; 004-707-001; AND 053-061-024 SAN LUIS OBISPO CITY AND COUNTY, CALIFORNIA PROJECT SL07509-10 1.0 Iti'TRODUCTION This update report presents the results of the geotechnical , .. Topo USAC:a investigation for the proposed "Orcutt Expansion Area Specific Plan" project which is bounded by Orcutt Road on the:: IN GENERAL North and East, Tank Farm r SITE AREA Road on the South and the - " r. �� Union Pacific Railroad on the West in both the city of San Luis Obispo and in the San 4 \ Luis Obispo area of San Luis _ Obispo County, California. Assessor Parcel Numbers (APN) included in this report are: 004-705-008; 004-706- — -. 002, 006, -007, -008, and - Bata 5es 009; 004-707-001; and 053- R DeLorme Tcec USA?28 0 6W „00 100 340 , 061-024, See Figure 1: Site P1" e �„s =, ,3-0 Location Map for the general location of the project area. Figure : Site Location Map Figure 1: Site Location Map was obtained from the computer program Topo USA 8.0 (DeLorme, 2009). This report serves as an update to the referenced Soils Engineering Report Update dated August 30, 2016 by GeoSolutions, Inc. (GeoSolutions, Inc., 2016). It is intended to address the applicable changes to the referenced report (GeoSolutions, Inc., 2016) required by the adoption of the 2016 California Building Code (CBSC, 2016) 1.1 Site DescriDtion The "Orcutt Expansion Area Specific Plan" project is located at 35.254508 degrees north latitude and 120.633424 degrees west longitude at a general elevation of 250 feet above mean sea level. The property is irregularly in shape and 160 acres in size. The Site is bounded by the Union Pacific Railroad on the west, Tank Farm Road on the south, Orcutt Road on the east and with an undefinable boundary on the north (see Figure 2: Site Plan. The nearest major intersection is where Orcutt Road intersects Tank Farm Road at the southeast corner of the property. The project property will hereafter be referred to as the "Site." See Figure 2: Site Plan for the general layout of the Site. Figure 2: Site Plan was obtained from Cannon Associates. The Site is characterized by flat to rolling grasslands with creeks and wetland areas which rise to a steep, rocky hill at the southeastern corner of the area known as Righetti Hill. Residential building pad areas are planned for a portion of the eastern side of the property along Orcutt Road and a majority of the west side of the property between the Union Pacific Railroad tracks and the base of Righetti Hill from Tank Farm Road to the northern Site boundary. The Site is undeveloped and currently utilized for cattle grazing. Orcutt Expansion Area Specific Plan January 8, 2019 Proiect SL07509-10 Surface drainage follows the topography to the southwestern corner of the Site. Native grasses and scattered trees currently vegetate the Site. 1.2 Proiect Description The proposed development is to include the construction of residential building pads, roadways, vehicular bridges, park areas, drainage facilities and associated improvements including but not limited to; sidewalks, site retaining walls, boundary walls, and detention basins. The proposed residences are anticipated to be one or two -stories in height and will be constructed utilizing light wood framing. It is anticipated that the proposed residences will use slab -on -grade lower floor systems. 2.0 PURPOSE ADD SCOPE The purpose of this study was to explore and evaluate the surface and sub -surface soil conditions at the Site and to develop geotechnical information and design criteria. The scope of this study includes the following items: A literature review of available published and unpublished geotechnical data pertinent to the project site including geologic maps, and available on-line or in-house aerial photographs. A field study consisting of site reconnaissance and subsurface exploration including exploratory borings in order to formulate a description of the sub -surface conditions at the Site. Laboratory testing performed on representative soil samples that were collected during our field study. Engineering analysis of the data gathered during our literature review, field study, and laboratory testing. 6e435nlutinnu" INC. Orcutt Expansion Area Specific Plan January 8. 2019 Pro'ect SL07509-10 B-8 B-9 �;E BORING LOCATIONS TRENCH -LOCATIONS 1PE RCOLATION TEST LOCATIONS FiuIirre ?: Site Plan Development of recommendations for site preparation and grading as well as geotechnical design criteria for building foundations, retaining walls, pavement sections, underground utilities, and drainage facilities. 3.0 FIELD AND LABOR_kTORY INVESTIGATION The field investigations were conducted between March 20 and March 25, 2013 using a John Deere 310G backhoe and a Mobile B-24 drill rig, on April 11, 2014 using a Mobile B-24 drill rig, on October 20, 2015 using a CME-55 drill rig and March 30 and June 8, 2016 using a backhoe. The surface and sub -surface conditions were studied by advancing a total of 14 exploratory borings and 13 exploratory trenches, as shown on Figure 2: Site Plan. The field investigation conducted between the dates of March 20 and March 25, 2013 utilized a John Deere 310G backhoe and a Mobile B-24 drill rig. The surface and sub -surface conditions were studied by advancing 6 exploratory trenches and 7 exploratory borings as shown on Figure 2: Site Plan. Sampling methods included the Standard Penetration Test utilizing a standard split -spoon sampler (SPT) and obtaining bulk samples from trenching operations and drill cuttings. The Mobile B-24 drill rig was equipped with a safety hammer, which has an efficiency of approximately 60 percent and was used to obtain test blow counts in the form of N-values. The backhoe was equipped with an 18-inch wide bucket. Data gathered during the field investigation suggest that the soil materials at the Site consist of colluvial soil overlying competent formational material of the Franciscan Complex. The surface materials at the Site generally consisted of dark brown Clayey SAND (SC) encountered in a dry to slightly moist and medium dense condition and dark brown to dark grayish brown sandy CLAY (CL-CH) encountered in a moist and firm to hard condition to approximately 3.0 feet bgs. Within the near surface sandy CLAY soils, desiccation cracks were observed to extend 24 to 36 inches below ground surface. The sub -surface materials consisted of dark yellowish brown to dark olive brown sandy CLAY with gravel (CL) GOUSUlutiOns. lNc. Orcutt Expansion Area Specific Plan January 8. 2019 Project SL07509-10 encountered in a moist and very stiff to hard condition to a maximum depth of 15 feet bgs. Between 3.0 feet bgs to termination of the trenches and borings at a maximum depth of 15 feet bgs, gravel content increased and cobbles were encountered, as well as evidence of weathered bedrock materials. The gravels and cobbles encountered within the borings and trenches have been identified as weathered Sandstone, Claystone, Chert and Serpentinite. Using the Geologic Map of the San Luis Obispo Quadrangle (Dibblee, 2004), these weathered bedrock materials were interpreted as representative of the Franciscan Complex. Groundwater was not encountered in any of the borings or trenches. In the areas of Trenches T-1, T-2 and Boring B-1, the surface and sub -surface soils were observed to extend to approximate depths of 6 to 15 feet below ground surface where the soil conditions transition to weathered bedrock materials which were encountered in soft to moderately hard conditions. Similar soil profiles were encountered within the slopes on the opposite side of Righetti Hill in the vicinity of Trenches T-3, T-4 and T-6 with the exception of Trench T-5 where fractured Chert was encountered at a depth of 1.0 foot below ground surface in a moderately hard to hard condition. In contrast, the soil profile within the generally flat -lying areas to the west and northwest of Righetti Hill consists of dark grayish brown sandy CLAY to depths of 3.5 to 5.0 feet bgs, underlain by weathered bedrock of the Franciscan Complex encountered in very severely weathered to moderately weathered and soft to very hard condition. It is anticipated that deep utility and drainage basin excavation may encounter hard digging conditions. April 11.2014 Field InvestiLyation The field investigation conducted on April 11, 2014 utilized a Mobile B-24 drill rig. Five four -inch diameter exploratory borings were advanced to a maximum depth of 10 feet below ground surface (bgs) at the approximate locations indicated on Figure 2: Site Plan. Sampling methods included the Standard Penetration Test utilizing a standard split -spoon sampler (SPT) without liners and a Modified. California sampler (CA) with liners. The Mobile B-24 drill rig was equipped with a safety hammer, which has an efficiency of approximately 60 percent and was used to obtain test blow counts in the form of N-values. Data gathered during the field investigation suggest that the soil materials at the Site consist of colluvial soil overlying competent formational material of the Franciscan Complex. The surface material at the Site generally consisted of brown Sandy CLAY (CL) with gravel and dark brown to black CLAY (CL) with cobbles of serpentinite encountered in a dry and stiff to very stiff condition to approximately 1.0 to 5.0 feet bgs. The sub -surface materials consisted of black CLAY (CL) with cobbles of serpentinite encountered in a very stiff condition underlain by Serpentinite Figure 3: Goode Earth Image Geasulutin"S, INC. Orcutt Expansion Area Specific Plan January 8. 2019 _ Project SL07509-10 and Greywacke Sandstone encountered in a very dense and hard condition. October 20, 2015 Field InvestiLyation The field investigation conducted on October 20, 2015 utilized a CME 55 drill rig. Two eight -inch diameter exploratory borings were advanced to a maximum depth of 15 feet below ground surface (bgs) at the approximate locations indicated on Figure 2: Site Plan. Sampling methods included the Standard Penetration Test utilizing a standard split -spoon sampler (SPT) without liners. The CME 55 drill rig was equipped with an auto -trip hammer, which has an efficiency of approximately 80 percent and was used to obtain test blow counts in the form of N-values. Data gathered during the field investigation suggest that the soil materials at the Site consist of colluvial soil overlying competent formational material of the Franciscan Complex. The surface material at the Site generally consisted of dark brown to gray sandy CLAY (CL) and olive clayey SAND (SC) encountered in a dry and stiff to very stiff condition to approximately 1.0 to 10.0 feet bgs. The sub -surface materials consisted of olive sandy CLAY (CL) encountered in a very stiff condition underlain by Serpentinite and Greywacke Sandstone encountered in a very dense and hard condition. March 30 and June 8.2016 Field Investiiation The field investigation conducted on March 30 and June 8, 2016 utilized a backhoe. An additional 7 exploratory trenches were advanced to a maximum depth of 7 feet below ground surface (bgs) at the approximate locations indicated on Figure 2: Site Plan. Sampling methods included bulk bags. Data gathered during the field investigation suggest that the soil materials at the Site consist of black sandy FAT CLAY (CH) encountered in a stiff to very stiff and dry condition to varying depths of 1.5 to 6.0 feet bgs. The underlying sub -surface materials consisted of gray/green to brown sandy CLAY (CL) encountered in a dry and hard condition and in some locations material representative of the Franciscan Complex was encountered in a very weathered and hard condition. In some locations undocumented fill materials were encountered in the upper 1.5 — 2 feet. Regional site geology was obtained by using the Geologic Map of the San Luis Obispo Quadrangle (Dibblee, 2004) and the MapView internet application (USGS, 2013); the later application is available from the United States Geological Survey website (USGS, 2013) and compiles existing geologic maps. The Serpentinite and Greywacke Sandstone and the majority of all underlying material at the Site was interpreted as representative of the Franciscan Complex and will hereafter be referred to as competent formational material. Groundwater was not encountered in any of the borings or trenches although it should be expected that groundwater elevations may vary seasonally and with irrigation practices. See Figure 4: Regional Geologic Map. 5 Gen5olutinn%, iNc. Orcutt Expansion Area Specific Plan January 8.2019 Proiect SL07509-10 [HUM —'A "Minch lA :Wd.wd�yc�ap�[MS+n Luk pbkpigw�kargk. 5.:.'-_uI; GLI �v%o:i,•!..:.�Iir�rr,i»: gpEMe Geelgjkel Pour-0a— 01[ e%vaitla Map OP 12--le 1ii9.Ox KALE 1'.240.',' :SPO OUAC'RANGLE OjQ INTERVAL 40 %EET Ratire 4: Re i'onal (serologic Map During the boring operations the soils encountered were continuously examined, visually classified, and sampled for general laboratory testing. A project engineer has reviewed a continuous log of the soils encountered at the time of field investigation. See Appendix A for the Boring Logs from the field investigation. Laboratory tests were performed on soil samples that were obtained from the Site during the field investigation. The results of these tests are listed below in Table 1: Engineering Properties. Laboratory data reports and detailed explanations of the laboratory tests performed during this investigation are provided in Appendix B. Table 1: Engineering Properties a X 'C ZSample Description a c $ c c o CA w � T-2 @ 2.0' Very Dark Grayish Brown Sandy CL 60.8 16 40 Low 113.0 13.0 to 3.0' CLAY T-2 @ 5.0' Dark Yellowish Brown Sandy CLAY CL 67.1 25 81 Medium - - to 6.0' T-3 @ 3.0' Very Dark Grayish Brown Fat CLAY CH - 46 94 High - - T-3 @ 6.0' Light Brownish Gray Sandy CLAY CL - 48 81 Medium - - to 7.0' T-6 @ 2.0' Dark Olive Brown Sandy CLAY CL 53.2 11 11 Very Low 116.2 12.4 6 INE. Orcutt Expansion Area Specific Plan January 8. 2019 Proiect SL07509-10 ample Description Z V 0 jr E W ae T-6 @ 5.0' Olive Brown Sandy CLAY CL - 14 44 Low - - B-3 @ 5.0' Light Olive Brown Sandy CLAY CL - 20 97 High - - to 10.0' B-7 @ 1.0' Very Dark Brown Sandy CLAY CH - 41 84 Medium - - to 3.0'. B-8 Black Sandy CLAY CL 69.5 27 62 Medium - - B-13 @ 0.0' Very Dark Brown Clayey SAND SC 38.3 22 58 Medium - to 3.0' C C i a� O Z Sample DescriptionQn O a' O c a w w A A Black Sandy FAT CLAY CH - 40 96 High - - T-7 @ 1.0' B Olive Clayey SAND SC - 18 48 Low - - T-7 @ 5.0' 4.0 I CY DROLOWC SOIL GROUP Based on the Web Soil Survey provided by the Natural Resources Conservation Service, the Site was initially designated as containing Hydrologic Soil Groups C and D. Groups C and D are similar in that they are both comprised of fine-grained soils with slow to very slow infiltration rates. The main distinction between the two groups is that Group D soil conditions are less favorable for infiltration of storm water and runoff due to; very slow infiltration rate (high runoff potential), clays with high shrink -swell potential, and soils that are shallow over nearly impervious material. Based on the sub -surface data obtained during the field investigation and the results of the laboratory testing, it is our opinion that the entire Site is best defined as Hydrologic Soil Group D. 5.0 SEISMIC DESIGN CONSIDERATIONS Estimating the design ground motions at the Site depends on many factors including the distance from the Site to known active faults; the expected magnitude and rate of recurrence of seismic events produced on fa�o5aiutts, INc. Orcutt Expansion Area Specific Plan January 8 2019 Pro'ect SL07509-10 such faults; the source -to -site ground motion attenuation characteristics; and the Site soil profile characteristics. According to section 1613 of the 2016 CBC (CBSC, 2016), all structures and portions of structures should be designed to resist the effects of seismic loadings caused by earthquake ground motions in accordance with the ASCE 7: Minimum Design Loads for Buildings and Other Structures, hereafter referred to as ASCE7-10 (ASCE, 2013). The Site soil profile classification (Site Class) can be determined by the average soil properties in the upper 100 feet of the Site profile and the criteria provided in Table 20.3-1 of ASCE7-10. Spectral response accelerations, peak ground accelerations, and site coefficients provided in this report were obtained using the computer -based Seismic Design Maps tool available from the Structural Engineers Association of California (SEAOC, 2018). This program utilizes the methods developed in the 1997, 2000, 2003, 2008 and 2013 errata editions of the NEHRP Recommended Provisions for Seismic Regulations for New Buildings and Other Structures in conjunction with user -inputted Site location to calculate seismic design parameters and response spectra (both for period and displacement) for soil profile Site Classes A through E. Site coordinates of 35.254508 degrees north latitude and-120.633424 degrees east longitude were used in the web -based probabilistic seismic hazard analysis (SEAOC, 2018). Based on the results from the in -situ tests performed during the field investigation, the Site was defined as Site Class D, "Stiff Soil" profile per ASCE7-10, Chapter 20. Relevant seismic design parameters obtained from the program area summarized in Table 2: Seismic Design Parameters. Refer to Appendix C for more information regarding the seismic hazard analysis performed for the project and detailed results. Table 2: Seismic Design Parameters rte Class - Site Class D, "Stiff Soil" Seismic Design Category D -Second Period Design Spectral Response Acceleration, SDI 0.459g Short -Period Design Spectral Response Acceleration, SDs 0.799g Site Specific MCE Peak Groun. celeration, PG 0.482g 6.0 LIQUEFACTION HAZARD _SSESSAILNT Liquefaction occurs when saturated cohesionless soils lose shear strength due to earthquake shaking. Ground motion from an earthquake may induce cyclic reversals of shear stresses of large amplitude. Lateral and vertical movement of the soil mass combined with the loss of bearing strength can result from this phenomenon. Liquefaction potential of soil deposits during earthquake activity depends on soil type, void ratio, groundwater conditions, the duration of shaking, and confining pressures on the potentially liquefiable soil unit. Fine, poorly graded loose sand, shallow groundwater, high intensity earthquakes, and long duration of ground shaking are the principal factors leading to liquefaction. Based on the consistency and relative density of the in -situ soils the potential for seismic liquefaction of soils at the Site is low. Assuming that the recommendations of the Soils Engineering Report are implemented, the potential for seismically induced settlement and differential settlement at the Site is considered to be low. 6e915131UU S, INC. Orcutt Expansion Area Specific Plan January 8 2019 Pro'ect SL07509-10 7.0 GE NEWAI, SOIL.:-FOU." DATION DISC [;SSION Based on the soil conditions encountered during the field investigation, it is anticipated that graded pads would be constructed for the proposed residences with foundations excavated into engineered fill. Due to the presence of highly expansive surface soils within the development areas, this report presents recommendations for building pad preparation with non -expansive import material beneath concrete slab - on -grade and exterior flatwork areas, as well as alternatives for mat foundations and post -tensioned slabs. All foundations are to be excavated into uniform material to limit the potential for distress of the foundation systems due to differential settlement. If cuts steeper than allowed by State of California Construction Safety Orders for "Excavations, Trenches, Earthwork" are proposed, a numerical slope stability analysis may be necessary for temporary construction slopes. Due the presence of shallow weathered bedrock materials encountered during the field investigation, hard rock excavation conditions are expected during development of building pad areas and underground utility construction. Natural seepage at the interface of two materials with different densities, such as native soil and competent formational material, is very common. This interface occurs at the Site and is likely to require sub -surface drains. Sub -drains should be placed in established drainage courses, potential seepage areas, and during the development of all key and bench grading operations. 8.0 CONCLUSIONS AND RECOMMENDATIONS The Site is suitable for the proposed development provided the recommendations presented in this report are incorporated into the project plans and specifications. The primary geotechnical concerns at the Site are: The presence of highly expansive surface soils. Expansive soils tend to swell when exposed to excess moisture and shrink when allowed to dry. The soil zone within the upper 2 to 3 feet of the Site is most affected by these seasonal changes in moisture content. The volume change associated with this soil movement can stress and damage foundations, concrete flatwork, interior slabs -on - grade, and roadway pavements. 2. The potential for loose soil materials generated from removal of existing trees and root systems within the proposed building pad areas. The presence of shallow, hard bedrock materials within the development. Hard digging/excavation conditions are anticipated during building pad preparation and underground utility construction. 4. The potential for differential settlement occurring between foundations supported on two soil materials having different settlement characteristics, such as native soil and engineered fill. Therefore, it is important that all of the foundations are founded in equally competent uniform material in accordance with this report. 7. t Prenaz•ation of BuildinLy Pads It is anticipated that graded engineered fill pads will be developed for the proposed development with footings founded in engineered fill. Due to the presence of highly expansive surface soils within the development, additional recommendations are provided EMM&AUUMM, Orcutt Expansion Area Specific Plan January 8. 2019 Proiect SL07509-10 for replacing the upper 24 inches of building pad and exterior flatwork areas with non - expansive import material. 2, For the development of an engineered fill pad with expansive native soils, the native material should be over -excavated at least 48 inches below existing grade, 24 inches below the bottom of the footings, to competent material, or to one-half the depth of the deepest fill; whichever is greatest. For fills over ten feet in height, the soils engineer should be contacted to provide specific grading recommendations for over -excavation of building pad areas. The limits of over -excavation should extend a minimum of 5 feet beyond the perimeter foundation, to property lines or existing improvements, whichever is least. The exposed surface should be scarified to a depth of 12 inches; moisture conditioned to at least 3 percent above optimum moisture content, and compacted to a minimum relative density of 90 percent (ASTM D1557-07). The over -excavated material, cleared of oversized aggregates and debris, may then be processed as engineered fill. Refer to Figure 5: Sub -Slab Detail for under -slab drainage material and Appendix D for more details on fill placement For the development of an engineered fill pad to receive conventional continuous perimeter footings with a non -expansive pad cap, the native material should be over - excavated at least 48 inches below existing grade, 24 inches below the bottom of the footings, to competent material, or to one-half the depth of the deepest fill; whichever is greatest. For fills over ten feet in height, the soils engineer should be contacted to provide specific grading recommendations for over -excavation of building pad areas. The limits of over -excavation should extend a minimum of 5 feet beyond the perimeter foundation, to property lines or existing improvements, whichever is least. The exposed surface should be scarified to a depth of 12 inches; moisture conditioned to at least 1 to 3 percent above optimum moisture content, and compacted to a minimum relative density of 90 percent (ASTM D1557-07). The over -excavated material, cleared of oversized aggregates and debris, should then be processed as engineered fill up to within 24 inches of the surface of the building pad. The upper 24 inches of building pad areas should consist of an approved non -expansive import material processed as engineered fill. All material to be used as non - expansive engineered fill must be observed and approved by a representative of GeoSolutions, Inc. prior to its delivery to the Site. Refer to Figure 5: Sub -Slab Detail for under -slab drainage material and Appendix D for more details on fill placement. For the development of an engineered fill pad to receive a mat foundation or post - tensioned slab, the native material should be over -excavated at least 24 inches below slab sub -grade elevation, to competent material, or to one-half the depth of the deepest fill for fills up to 10 feet; whichever is greatest. The exposed surface should be scarified to a depth of 12 inches; moisture conditioned to at least 1 to 3 percent above optimum moisture content, and compacted to a minimum relative density of 90 percent (ASTM D1557-07). The over -excavated material, cleared of oversized aggregates and debris, may then be processed as engineered fill. However, as an alternative the over -excavated material may be replaced with an approved non -expansive import material processed as engineered fill so that at a minimum, the upper 24 inches of the pad area consists of non - expansive material. The non -expansive material is intended to; retain soil moisture in the graded pad and reduce the potential for soil drying and shrinkage prior to concrete placement. All material to be used as non -expansive engineered fill must be observed and approved by a representative of GeoSolutions, Inc. prior to its delivery to the Site. Refer to Figure 5: Sub -Slab Detail for under -slab drainage material and Appendix D for more details on fill placement. 10 CNanS011- inr1,ra.INC. Orcutt Expansion Area Specific Plan January 8. 2019 Pro'ect SL07509-10 Where fill areas are constructed on slopes greater than 10-to-1 (horizontal -to -vertical), we recommend that benches be cut every four feet as fill is placed. Each bench shall be a minimum of 10 feet wide with a minimum of two percent gradient into the slope. If fill areas are constructed on slopes greater than 5-to-1, we recommend that the toe of all areas to receive fill be keyed a minimum of 24 inches into underlying dense material. Sub -drains shall be placed in the keyway and benches as required. See Appendix D, Detail A, Key and Bench with Backdrain for details on key and bench construction. The recommended soil moisture content should be maintained during construction and following construction of the proposed development. Where soil moisture content is not maintained, desiccation cracks may develop which indicate a loss of soil compaction, leading to the potential for damage to foundations, flatwork, pavements, and other improvements. Soils that have become cracked due to moisture loss should be removed to sufficient depth to repair the cracked soil as observed by the soils engineer, and the removed material should then be moisture conditioned to at least 1 to 3 percent over optimum value, and compacted. Imped OAFIM 4" !l � -t~ u.��cptltstta ri +A Hu ire S: Sub -Slab Detail 7.2 Preuaration of Paved . reas Pavement areas should be excavated to approximate sub -grade elevation or to competent material; whichever is deeper. The exposed surface should be scarified an additional depth of 8 inches, moisture conditioned to at least 1 to 3 percent above optimum value, and compacted to a minimum relative density of 95 percent (ASTM D1557-07 test method). The top 12 inches of sub -grade soil under all pavement sections should be compacted to a minimum relative density of 95 percent based on the ASTM D1557-07 test method at slightly above optimum. Sub -grade soils should not be allowed to dry out or have excessive construction traffic between moisture conditioning and compaction, and placement of the pavement structural section. Due to the expansive potential of the soils at the Site, the base courses beneath un- reinforced pavement sections may fail, causing cracking of the pavement surfaces, as the sub -grade materials move laterally during expansive shrink -swell cycles. 11 INC. Orcutt Expansion Area Specific Plan January 8. 2019 Project SL07509-10 Therefore, in order to minimize the potential for the failure of pavement sections at the Site, GeoSolutions, Inc. recommends that a laterally -reinforcing biaxial geogrid, such as Tensar BX1100, Tenax MS220, Syntec SBX11, or equivalent, be installed to reinforce the base courses under paved areas at the Site. GeoSolutions, Inc. should be contacted prior to the design and construction of pavement sections at the Site in order to assist in the selection of an appropriate laterally -reinforcing biaxial geogrid product and to provide recommendations regarding the procedures for the installation of geogrid products at the Site. 7.3 Pavement Design All pavement construction and materials used should conform to Sections 25, 26 and 39 of the latest edition of the State of California Department of Transportation Standard Specifications (State of California, 1999). 2. As indicated previously in Section 7.2, the top 12 inches of sub -grade soil under pavement sections should be compacted to a minimum relative density of 95 percent based on the ASTM D1557-07 test method at slightly above optimum moisture content. Aggregate bases and sub -bases should also be compacted to a minimum relative density of 95 percent based on the aforementioned test method. i. Based on the soil conditions observed and the results of the laboratory testing performed on surface soils within the Site, an R-Value of 5 is estimated for preliminary pavement design purposes. A minimum of 10 inches of Class Il Aggregate Base is recommended for all pavement sections. All pavement sections should be crowned for good drainage. In order to minimize the potential for cracking of the pavement surfaces at the Site due to lateral movement of the base courses during expansive shrink -swell cycles of the sub - grade materials, GeoSolutions, Inc. recommends that a laterally -reinforcing biaxial geogrid, such as Tensar BX1100, Tenax MS220, Syntec SBX11, or equivalent, be installed between the prepared sub -grade and base materials at the Site. GeoSolutions, Inc. should be contacted prior to the design and construction of the pavement sections to provide recommendations regarding the selection of and installation of an appropriate laterally -reinforcing biaxial geogrid product. 7.4 Conventional Foundations Conventional continuous and spread footings with grade beams may be used for support of the proposed structure. Isolated pad footings are not allowed. Foundations must be designed in accordance to section 1808.6, 2016 CBC, Foundations on Expansive Soils. Minimum footing and grade beam sizes and depths in engineered fill comprised of expansive native soil should conform to the following table, as observed and approved by a representative of GeoSolutions, Inc. 12 6LF"SU1UtiG_n_S, INE. Orcutt Expansion Area Specific Plan Januaa 8. 2019 Pro'ect SL07509-10 Table 3: Minimum Footin,= and Grade Beam Dimensions (Expansive `-��- " Perimeter Footings Grade Beams 12 inches (one story) Minimum Width 12 inches 15 inches (two story) Embedment Depth 30 inches 18 inches Minimum 6 #5 bars 4 #5 bars Reinforcing* (3 top / 3 bottom) (2 top / 2 bottom) Spacing - 16 feet on -center each way * Steel should be held in place by stirrups at appropriate spacing to ensure proper positioning of the steel (see WRI Design of Slab -on -Ground Foundations and ACI 318, Section 7.5 — Placing Reinforcement). As an alternative, if a minimum of 24 inches of non -expansive import material is placed on the surface of the building pad areas, the minimum footing and grade beam sizes and depths in engineered fill should conform to the following table, as observed and approved by a representative of GeoSolutions, Inc. Table 4: !Minimum Footin�, and Grade F>eam Dimensions (24 inches of Non -Expansive) Perimeter Footings Grade Beams 12 inches (one story) Minimum Width 12 inches 15 inches (two story) Embedment Depth 24 inches 18 inches Minimum 4 #5 bars 4 #4 bars Reinforcing* (2 top / 2 bottom) (2 top / 2 bottom) Spacing I - 19 feet on -center each way * Steel should be held in place by stirrups at appropriate spacing to ensure proper positioning of the steel (see WRI Design of Slab -on -Ground Foundations and ACI 318, Section 7.5 — Placing Reinforcement). Minimum reinforcing for footings should conform to the recommendations provided in Table 2 or Table 3 which meet the specifications of Section 1808.6 of the 2016 California Building Code for the soil conditions at the Site. Reinforcing steel should be held in place by stirrups at appropriate spacing to ensure proper positioning of the steel in accordance with WRI Design of Slab -on -Ground Foundations, and ACI 318, Section 7.5 — Placing Reinforcement. A representative of this firm should observe and approve all foundation excavations for required embedment depth prior to the placement of reinforcing steel and/or concrete. Concrete should be placed only in excavations that are free of loose, soft soil and debris and that have been maintained in a moist condition with no desiccation cracks present. 13 GOOSIMIUV0175, INC. Orcutt Expansion Area Specific Plan January 8.2019 Proiect SL07509-10 An allowable dead plus live load bearing pressure of 1,500 psf may be used for the design of footings founded in engineered fill. 7. A total settlement of less than 1 inch and a differential settlement of less than 1 inch in 30 feet are anticipated. Lateral forces on structures may be resisted by passive pressure acting against the sides of shallow footings and/or friction between the engineered fill and the bottom of the footings. For resistance to lateral loads, a friction factor of 0.30 may be utilized for sliding resistance at the base of footings extending a minimum of 24 inches into engineered fill. A passive pressure of 250-pcf equivalent fluid weight may be used against the side of shallow footings in engineered fill. If friction and passive pressures are combined to resist lateral forces acting on shallow footings, the lesser value should be reduced by 50 percent. «. Foundation excavations should be observed and approved by a representative of this firm prior to the placement of reinforcing steel and/or concrete. 1 :?. Foundation design should conform to the requirements of Chapter 18 of the latest edition of the CBC (CBSC, 2016). 1 . The base of all grade beams and footings should be level and stepped as required to accommodate any change in grade while still maintaining the minimum required footing embedment and slope setback distance. 1'. The minimum footing setback distance from ascending or descending steeper than 3-to-1 (horizontal -to -vertical) but less than 1-to-1 must be maintained. See Figure 6: Setback Dimensions — Slope Gradients Between 3-to-1 and 1-to-1 Setback Dimensions — Slope Gradients Between 3-to-1 and 1-to-1 for the minimum horizontal setback distances from ascending and descending slopes steeper than 3-to-1 but not steeper than 1-to-1. FACE OF FOOTING TOP OF SLOPE FACE OF STRUCTURE TOE OF SLOPE 1-1/3 BUT NEED NOT EXCEED 40 FT. (12 192 mm) MAX. H/2 BUT NEED NOT EXCEED 15 FT. (4572 mm) MAX. Figure 6: Setback Dimensions— elope Gradients Between 3-to-1 and 1--to-1 7.5 Mat Foundations Mat foundations may be used for support of the proposed residences. Foundations such as mat slabs require a minimal amount of over -excavation for building pad preparation. For this Site we anticipate that mat foundations would be 10 to 12 inches thick. Building pad 14 �Ipffi_'LffU0MI, INC. Orcutt Expansion Ai -ea Specific Plan January 8.2019 Proiect SL07509-10 preparation for areas to receive mat foundations should be prepared in accordance with section 7.1.4 of this report. 2. Allowable dead and live load bearing pressure of 1,500 psf may be used for design of a mat foundation. A modulus of sub -grade reaction (k) of 100 pci may be used in design of a mat foundation. Lateral forces on structures may be resisted by passive pressure acting against the sides of shallow footings and/or friction between the engineered fill and the bottom of the mat. For resistance to lateral loads, a friction actor of 0.3 may be utilized for sliding resistance at the base of footings or slab, with no increase permitted when considering load combinations, including wind or earthquake loads. 7.b Post-Tension-ed Slabs Post -tension slabs should be designed in accordance with the recommendations presented in the most recent edition of Design of Post -Tensioned Slabs -on -Ground, by the Post - Tensioning Institute (PTI) and the 2016 California Building Code for expansive soils in the "high" category. Post -tensioned slabs should be designed according to the method recommended in the Design and Construction of Post -Tensioned Slabs -on -Ground (PTI, 2012 PTI DC 10.5- 12). As a guideline, the following soil design criteria for the post -tensioned slab foundations may be used: Table 5: Post Tension Foundation Design Criteria POST -TENSION FOUNDATION DESIGN CRITERIA 1K Expansion Potential Center Lift I Edge Lift Em (ft.) Ym (in.) I Em (ft.) I Ym (in.) High 9.0 0.6 I 4.9 1.5 The post -tensioned slabs should be designed using maximum allowable bearing capacities of 1,000 psf dead load, 1,500 psf for dead -plus -live loads, and a sub -grade modulus (k) of 100 pci. These soil bearing values may be increased by one-third when considering total loads including wind or seismic loads. Prior to the construction of post -tensioned slab foundations, the exposed soil within the graded pad prepared in accordance with Section 7.1.4, should be maintained at a minimum moisture content of 130 percent of optimum moisture, to a minimum depth of 18 inches below pad grade. 7.7 Slab -On -Grade Construction Concrete slabs -on -grade and flatwork should not be placed directly on unprepared native materials. Preparation of sub -grade to receive concrete slabs -on -grade and flatwork should be processed as discussed in the preceding sections of this report. Concrete slabs should be placed only over sub -grade that is free of loose, soft soil and debris and that has been 15 INC. Orcutt Expansion Area Specific Plan January 8, 2019 Project SL07509-10 that has been maintained in a moist condition with no desiccation cracks prior to concrete placement. Concrete slabs -on -grade should be in conformance with the recommendations provided in Table 5 (expansive soil) and Table 6 (minimum 24 inches non -expansive import). Reinforcing should be placed on -center both ways at or slightly above the center of the structural section. Reinforcing bars should have a minimum clear cover of 1.5 inches. Where lapping of the slab steel is required, laps in adjacent bars should be staggered a minimum of every five feet (see WRI/CSRI-81 recommendations for Steel Placement, Section 2). The recommended reinforcement may be used for anticipated uniform floor loads not exceeding 200 psf. If floor loads greater than 200 psf are anticipated, a Structural Engineer should evaluate the slab design. Table 6: Mininnnn Slab Recommen lations — ExpansiveNa6ve Soil � Minimum Thickness 1 5 inches I II Reinforcing* 1 #4 bars at 16 inches on -center each wav II * Where lapping of the slab steel is required, laps in adjacent bars should be staggered a minimum of every five feet (see WRI/CSRI-81 recommendations for Steel Placement, Section 2). Table 7: Minimum Slab RPcnmmenda.tions --ikon-Expansive Impor-_ Minimum Thickness 4 inches Reinforcing* #3 bars at 18 inches on -center each way * Where lapping of the slab steel is required, laps in adjacent bars should be staggered a minimum of every five feet (see WRI/CSRI-81 recommendations for Steel Placement, Section 2). Concrete for all slabs should be placed at a maximum slump of less than 5 inches. Excessive water content is the major cause of concrete cracking. If fibers are used to aid in the control of cracking, a water -reducing admixture may be added to the concrete to increase slump while maintaining a water/cement ratio, which will limit excessive shrinkage. Control joints should be constructed as required to control cracking. Where concrete slabs -on -grade are to be constructed, the slabs should be underlain by a minimum of 4 inches of clean free -draining material, such as a '/2 inch coarse aggregate mix, to serve as a cushion and a capillary break. Where moisture susceptible storage or floor coverings are anticipated, a 15-mil Stego Wrap membrane (or equivalent installed per manufacturer's specifications) should be placed between the free -draining material and the slab to minimize moisture condensation under the floor covering. See Figure 5: Sub - Slab Detail for the placement of under -slab drainage material. It is suggested, but not required, that a 2-inch thick sand layer be placed on top of the membrane to assist in the curing of the concrete, increasing the depth of the under -slab material to a total of 6 inches. The sand should be lightly moistened prior to placing concrete. It should be noted that for a vapor barrier installation to conform to manufacturer's specifications, sealing of penetrations, joints and edges of the vapor barrier membrane may be required. If the installation is not performed in accordance with the manufacturer's 16 6en5nlutinns, INC. Orcutt Expansion Area Specific Plan January 8 2019 Proiect SL07509-10 specifications, there is an increased potential for water vapor to affect the concrete slabs and floor coverings. The most effective method of reducing the potential for moisture vapor transmission through concrete slabs -on -grade would be to place the concrete directly on the surface of the vapor barrier membrane. However, this method requires a concrete mix design specific to this application with low water -cement ratio in addition to special concrete finishing and curing practices, to minimize the potential for concrete cracks and surface defects. The contractor should be familiar with current techniques to finish slabs poured directly onto the vapor barrier membrane. 6. Moisture condensation under floor coverings has become critical due to the use of water- soluble adhesives. Therefore, it is suggested that moisture sensitive slabs not be constructed during inclement weather conditions. ?.$ Exterior Concrete Elanvarl. Due the presence of highly expansive surface soils within the proposed development areas, there is a high potential for considerable soil movement and flatwork if conventional measures are used, such as the placement of 4 to 6 inches of imported sand materials placed beneath concrete flatwork. Heaving and cracking are anticipated to occur. To reduce the potential for movement associated with expansive soils, we recommend the placement of a minimum of 24 inches of approved non -expansive import material placed as engineered fill beneath the flatwork. ?. Minimum flatwork reinforcement should consist of No. 3 reinforcing steel bars placed at 24 inches on -center each -way at or slightly above the center of the structural section. Flatwork should be constructed with frequent joints to allow for movement due to fluctuations in temperature and moisture content in the adjacent soils. Flatwork at doorways, driveways, curbs and other areas where restraining the elevation of the flatwork is desired, should be doweled to the perimeter foundation by a minimum of No. 3 reinforcing steel dowels, spaced at a maximum distance of 24 inches on -center. 7.9 TeMDoratir Slope Stabiliiv It is our understanding that the preliminary grading of the Tract will include construction of 1:1 (horizontal to vertical) temporary slopes behind proposed retaining walls. The soils encountered during the field investigation within the Tract consisted of colluvial soil materials overlying competent formational material of the Franciscan Complex. The surface soils have been described as cohesive, clay soils, sandy clay and clayey sands, which correspond to Type A soil in accordance with OSHA standards for construction excavations (Standard 1926 — Safety and Health Regulations for Construction, Sub -Part P — Excavations). Additional OSHA specifications for Type A soils are that they exhibit an in -place compressive strength of 1.5 tons per square foot, which is anticipated to be exceeded by in -place conditions and is to be verified in the field during construction by the Soils Engineer. ?. The potential exists for the exposed soils in the temporary slopes to shrink and crack from moisture loss during construction, which would change the soil classification from Type A to Type B per OSHA guidelines. For the purposes of this discussion, we are providing 17 N—ULIEMS,INC. Orcutt Expansion Area Specific Plan January 8. 2019 Project SL07509-10 maximum slope configurations based on Type B soil materials. Type B soils are similar to Type A with a reduced unconfined compressive strength of 0.5 to 1.5 tons per square foot and described that the soil may be cracked and may have been disturbed by construction activities. Temporary excavations in Type B soil material are allowed a maximum slope of 1:1 (45 degrees) for a maximum height of 20 feet. We do not anticipate that any of the proposed slopes will exceed the maximum of 1:1 horizontal to vertical, or the maximum height of 20 feet. The Soils Engineer will inspect the condition of the slopes and slope materials exposed during construction to verify the exposed soil types and to confirm that the temporary slopes are in conformance with OSHA specifications. 7.10 Retaining Walls Retaining walls should be designed to resist lateral pressures from adjacent soils and surcharge loads applied behind the walls. We recommend using the lateral pressures presented in Table 8: Retaining Wall Design Parameters and Figure 7: Retaining Wall Detail for the design of retaining walls at the Site. The Active Case may be used for the design of unrestrained retaining walls, and the At -Rest Case may be used for the design of restrained retaining walls. TA]c 8: Retaining Wall r� ..��., p�ramet rs Lateral Pressure and Condition Equivalent Fluid Pressure, pcf Static, Active Case, Engineered Fill 35 (imported sand or gravel backfill) (y'KA) Static, Active Case, Engineered Fill 60 (Native) (y'KA) Static, At -Rest Case, Engineered Fill 50 (imported sand or gravel backfill) (y'Ko) Static, At -Rest Case, Engineered Fill 85 (Native) (y'Ko) Static, Passive Case, Engineered Fill (y'KP) 250 Static, Passive Case, Competent Formational Material (y'KP) 400 18 f IEO5OlUtiOng, iNE. Orcutt Expansion Area Specific Plan January 8. 2019 Proiect SL07509-10 12" minimum L The above values for equivalent fluid pressure Mirafi 140N are based on retaining or equivalent walls having level retained Ka = varies surfaces, having an Ko = varies approximately vertical surface against the retained material, and retaining Kp = 250 pcf granular backfill material or engineered fill composed Of native soil Permeable Drain Rock within the active wedge. See Figure 7: Retaining S 4" Dia. Per£ Drain Pipe Wall Detail and Figure 8: Retaining Wall Active and Max Toe Pressure: 1,800 psf Passive Wedges for a description of the location of the active wedge behind Figure 7: Retaining Wail Detail a retaining wall. Proposed retaining walls having a retained surface that slopes upward from the top of the wall should be designed for an additional equivalent fluid pressure of 1 pcf for the active case and 1.5 pcf for the at -rest case, for every two degrees of slope inclination. This applies for slope angles up to 20 degrees; a 20-degree slope is approximately equivalent to a slope with a 2.75-to-1 gradient. - ?. We recommend that the proposed retaining walls at the Site have an approximately vertical surface against the retained material. If the proposed retaining walls are to have sloped surfaces against the retained material, the project designers should contact the Soils Engineer to determine the appropriate lateral earth pressure values for retaining walls located at the Site. Claycy Material Drairap Swale Wall `. Active- Wedge - Permeable Drain Rock L.evcl Backtill Not to scale 4-Inch Perf. Drain Pipe 'fl 45° 'T 45' +(V2 1• Passive Wedge Figure 8: Retaining Wall active and Passive Wedges Ul 19 GRo5UIutions, INC. Orcutt Expansion Area Specific Plan January 8 2019 Proiect SL07509-10 Retaining wall foundations should be founded a minimum of 24 inches below lowest adjacent grade in engineered fill as observed and approved by a representative of GeoSolutions, Inc. A coefficient of friction of 0.30 may be used between engineered fill and concrete footings. Project designers may use a maximum toe pressure of 1,800 psf for the design of retaining wall footings founded in engineered fill. For earthquake conditions, retaining walls greater than 6 feet in height should be designed to resist an additional seismic lateral soil pressure of 25 pcf equivalent fluid pressure for unrestrained walls (active condition). The pressure resultant force from earthquake loading should be assumed to act a distance of 113H above the base of the retaining wall, where H is the height of the retaining wall. Seismic active lateral earth pressure values were determined using the simplified dynamic lateral force component (SEAOC 2010) utilizing the design peak ground acceleration, PGAM, discussed in Section 5.2 (PGAM = 0.465g). The dynamic increment in lateral earth pressure due to earthquakes should be considered during the design of retaining walls at the Site. Based on research presented by Dr. Marshall Lew (Lew et al., 2010), lateral pressures associated with seismic forces should not be applied to restrained walls (at -rest condition). Seismically induced forces on retaining walls are considered to be short-term loadings. Therefore, when performing seismic analyses for the design of retaining wall footings, we recommend that the allowable bearing pressure and the passive pressure acting against the sides of retaining wall footings be increased by a factor of one-third. In addition to the static lateral soil pressure values reported in Table 8: Retaining Wall Design Parameters, the retaining walls at the Site should be designed to support any design live load, such as from vehicle and construction surcharges, etc., to be supported by the wall backfill. If construction vehicles are required to operate within 10 feet of a retaining wall, supplemental pressures will be induced and should be taken into account in the design of the retaining wall. G. The recommended lateral earth pressure values are based on the assumption that sufficient sub -surface drainage will be provided behind the walls to prevent the build-up of hydrostatic pressure. To achieve this we recommend that a granular filter material be placed behind all proposed walls. The blanket of granular filter material should be a minimum of 12 inches thick and should extend from the bottom of the wall to 12 inches from the ground surface. The top 12 inches should consist of moisture conditioned, compacted, clayey soil. Neither spread nor wall footings should be founded in the granular filter material used as backfill. 10. A 4-inch diameter perforated or slotted drainpipe (ASTM D1785 PVC) should be installed near the bottom of the filter blanket with perforations facing down. The drainpipe should be underlain by at least 4 inches of filter type material and should daylight to discharge in suitably projected outlets with adequate gradients. The filter material should consist of a clean free -draining aggregate, such as a coarse aggregate mix. If the retaining wall is part of a structural foundation, the drainpipe must be placed below finished slab sub -grade elevation. 1. The filter material should be encapsulated in a permeable geotextile fabric. A suitable permeable geotextile fabric, such as non -woven needle -punched Mirafi 140N or equal, may be utilized to encapsulate the retaining wall drain material and should conform to Caltrans Standard Specification 88-1.03 for underdrains. 20 Gen5nlutiOng, iNc. Orcutt Expansion Area Specific Plan January 8, 2019 Project SL07509-10 2. For hydrostatic loading conditions (i.e. no free drainage behind retaining wall), an additional loading of 45-pcf equivalent fluid weight should be added to the active and at - rest lateral earth pressures. If it is necessary to design retaining structures for submerged conditions, the allowed bearing and passive pressures should be reduced by 50 percent. In addition, soil friction beneath the base of the foundations should be neglected. 3. Precautions should be taken to ensure that heavy compaction equipment is not used adjacent to walls, so as to prevent undue pressure against, and movement of the walls. 1 A�, The use of water-stops/impermeable barriers should be used for any basement construction, and for building walls that retain earth. '.11 Bridae Abutments It is anticipated the bridge abutment foundations for the drainage crossings will be excavated into the competent formational material encountered at approximate flow line elevation during the field investigation. Foundations for bridge abutments should be excavated a minimum of 24 inches below lowest adjacent grade with a minimum embedment of 12 inches into competent formational material, as observed and approved by a representative of GeoSolutions, Inc. A coefficient of friction of 0.45 may be used between competent formational material and concrete abutment footings. A modulus of sub -grade reaction (k,) of 500 pci may be used in design for competent formational material. Allowable dead plus live load bearing pressure of 4,000 psf may be used for design of bridge abutment foundations in competent formational material. 9.0 AI)D►ITIONAL GLOTEGUNICAL SERVICES The recommendations contained in this report are based on a limited number of borings and trenches, and on the continuity of the sub -surface conditions encountered. GeoSolutions, Inc. assumes that it will be retained to provide additional services during future phases of the proposed project. These services would be provided by GeoSolutions, Inc. as required by City and County of San Luis Obispo, the 2016 CBC, and/or industry standard practices. These services would be in addition to those included in this report and would include, but are not limited to, the following services: Consultation during plan development. 2. Plan review of grading and foundation documents prior to construction and a report certifying that the reviewed plans are in conformance with our geotechnical recommendations. Consultation during selection and placement of a laterally -reinforcing biaxial geogrid product. Construction inspections and testing, as required, during all grading and excavating operations beginning with the stripping of vegetation at the Site, at which time a site meeting or pre job meeting would be appropriate. 5. Special inspection services during construction of reinforced concrete, structural masonry, high strength bolting, epoxy embedment of threaded rods and reinforcing steel, and welding of structural steel. 21 GRnSoiutiOns, INc. Orcutt Expansion Area Specific Plan January 8.2019 Proiect SL07509-10 Preparation of construction reports certifying that building pad preparation and foundation excavations are in conformance with our geotechnical recommendations. Preparation of special inspection reports as required during construction. In addition to the construction inspections listed above, section 1705.6 of the 2016 CBC (CBSC, 2016) requires the following inspections by the Soils Engineer for controlled fill thicknesses greater than 12 inches as shown in Table 9: Required Verification and Inspections of Soils: Table 9: Regrured Verification ind incneo Lions of Soils - - Continuous Periodically Verification and Inspection Task During Task During Task Listed Listed 1. Verify materials below footings are adequate to achieve the - X design bearing capacity. 2. Verify excavations are extended to proper depth and have X reached proper material. 3. Perform classification and testing of controlled fill materials. - X 4. Verify use of proper materials, densities and lift thicknesses X - during placement and compaction of controlled fill. 5. Prior to placement of controlled fill, observe sub -grade and - X verify that site has been prepared properly. 10.0 LIIIITATIONS AND UNIFORMITY OF CONDITIONS The recommendations of this report are based upon the assumption that the soil conditions do not deviate from those disclosed during our study. Should any variations or undesirable conditions be encountered during the development of the Site, GeoSolutions, Inc. should be notified immediately and GeoSolutions, Inc. will provide supplemental recommendations as dictated by the field conditions. This report is issued with the understanding that it is the responsibility of the owner or his/her representative to ensure that the information and recommendations contained herein are brought to the attention of the architect and engineer for the project, and incorporated into the project plans and specifications. The owner or his/her representative is responsible to ensure that the necessary steps are taken to see that the contractor and subcontractors carry out such recommendations in the field. As of the present date, the findings of this report are valid for the property studied. With the passage of time, changes in the conditions of a property can occur whether they are due to natural processes or to the works of man on this or adjacent properties. Therefore, this report should not be relied upon after a period of 3 years without our review nor should it be used or is it applicable for any properties other than those studied. However many events such as floods, earthquakes, grading of the adjacent properties and building and municipal code changes could render sections of this report invalid in less than 3 years. \\NAS-CI-DF-18\s\SL07500-SLO7999\SLO7509-8 - Orcutt Specific Pratt SER\Engineering\SL07509-8 Orcutt Expansion Area Specific Plan SER.doc 22 GM ORj:INC. REFERENCES GeoSolutions, stir. REFERE'S CES American Society of Civil Engineers (ASCE). Minimum Design Loads for Buildings and Other Structures. ASCE Standard ASCE/SEI 7-05 Including Supplement No. 1. 1801 Alexander Bell Drive, Reston, Virginia 20191. 2006. California Building Standards Commission (CBSC). (2016). 2016 California Building Code, California Code of Regulations, Title 24. Part 2, Vol. 2. DeLorme. Topo USA 8.0. Vers.8.0.0 Computer software. DeLorme, 2009. Microsoft Windows 7, DVD- ROM drive. Dibblee, Thomas W., Jr.. Geologic Map of the San Luis Obispo Quadrangle. Dibblee Geologic Center Map Number DF-129. Santa Barbara Museum of Natural History: 2004. Liquefy Pro Version 5.8f software by CivilTech. State of California. Department of Industrial Relations. California Code of Regulations. 2001 Edition. Title 8. Chapter 4: Division of Industrial Safety. Subchapter 4, Construction Safety Orders. Article 6: Excavations. http://www.dir.ca.gov/title8/sub4.html. State of California, Department of Transportation. Standard Specifications. State of California Department of Transportation Central Publication Distribution Unit: July 1999. Structural Engineers Association of California (SEAOC), Seismic Design Maps, accessed January 8, 2019. <https://seismicmaps.org/>. United States Geological Survey. Map View — Geologic Maps of The Nation. Internet Application. USGS, 26 August, 2013. < http://ngmdb.usgs.gov/maps/MapView/> GeoSIAUVons, INC. Field Investigation Soil Classification Chart Boring Logs Trench Logs 6eo5alutir�ns, E�v�. FIELD IVVESTIGATION The field investigations were conducted between March 20 and March 25, 2013 using a John Deere 310G backhoe and a Mobile B-24 drill rig, on April 11, 2014 using a Mobile B-24 drill rig, on October 20, 2015 using a CME-55 drill rig and March 30 and June 8, 2016 using a backhoe. The surface and sub -surface conditions were studied by advancing a total of 14 exploratory borings and 13 exploratory trenches, as shown on Figure 2: Site Plan. This exploration was conducted in accordance with presently accepted geotechnical engineering procedures consistent with the scope of the services authorized to GeoSolutions, Inc. The Mobile B-24 drill rig with a four -inch diameter solid -stem continuous flight auger bored five exploratory borings near the approximate locations indicated on Figure 2: Site Plan. The drilling and field observation was performed under the direction of the project engineer. A representative of GeoSolutions, Inc. maintained a log of the soil conditions and obtained soil samples suitable for laboratory testing. The soils were classified in accordance with the Unified Soil Classification System. See the Soil Classification Chart in this appendix. Standard Penetration Tests with a two-inch outside diameter standard split tube sampler (SPT) without liners (ASTM D1586-99) and a three-inch outside diameter Modified California (CA) split tube sampler with liners (ASTM D3550-01) were performed to obtain field indication of the in -situ density of the soil and to allow visual observation of at least a portion of the soil column. Soil samples obtained with the split spoon sampler are retained for further observation and testing. The split spoon samples are driven by a 140-pound hammer free falling 30 inches. The sampler is initially seated six inches to penetrate any loose cuttings and is then driven an additional 12 inches with the results recorded in the boring logs as N-values, which area the number of blows per foot required to advance the sample the final 12 inches. The CA sampler is a larger diameter sampler than the standard (SPT) sampler with a two-inch outside diameter and provides additional material for normal geotechnical testing such as in -situ shear and consolidation testing. Either sampler may be used in the field investigation, but the N-values obtained from using the CA sampler will be greater than that of the SPT. The N-values for samples collected using the CA can be roughly correlated to SPT N-values using a conversion factor that may vary from about 0.5 to 0.7. A commonly used conversion factor is 0.67 (z/3). More information about standardized samplers can be found in ASTM D1586-99 and ASTM D3550-01. Disturbed bulk samples are obtained from cuttings developed during boring operations. The bulk samples are selected for classification and testing purposes and may represent a mixture of soils within the noted depths. Recovered samples are placed in transport containers and returned to the laboratory for further classification and testing. Logs of the borings and trenches showing the approximate depths and descriptions of the encountered soils, applicable geologic structures, recorded N-values, and the results of laboratory tests are presented in this appendix. The logs represent the interpretation of field logs and field tests as well as the interpolation of soil conditions between samples. The results of laboratory observations and tests are also included in the boring logs. The stratification lines recorded in the boring logs represent the approximate boundaries between the surface soil types. However, the actual transition between soil types may be gradual or varied. GeoSolutions, INc. SOIL CLASSIFICATION CHART MAJOR Pik ISIONN LABORkIORN CLASSIPICALIONCR11FRIA GROI P PRIM %RV DIN MONS L""'els and Co grente, than 4 and C, between 1 and 3 GA'* coi,cu"." little'), no fines Clean gravels Ocss GRAVELS than 51r6 fines') Polbigad,d grs,��!s ..,it gl­a,cl-s�nd Not inecting both criteria far GW GI` rnw-n-es, little Orin, fines, More ma. 501y" of ...rsc Atterb.rg limits plot below "A" Inn, .1 plasticity ; ftactl.o ctsil,incd on N No' I ill, floes Gravel ;title, less than 4 GNI Silly c­;lls; grave; -sand -sill mixuu is 4 (4.75n,") sieve (nine than i 2% Atterberg limits plot below "A" line and plasticity GC Clayey -sand -day oxmnoos COARSE GRAINED SOILS fines*) Mora than SW,6 retained oil No. index greater than 7 gravels, gravel Well graded sands. g,a,cly —id,, ;lath or C, greater than 6 and C, bet—c. 1 ..,it 3 SW Clean sand (h,ss no line, poorly graded sand; and g-61y slid that, fines.) Not meeting both criteria for SW S11 sand;, little or no fines Mine than 50i, ofccarse AuerberI; limits plot below "A" line ., plasticity:iacdo i passes Na. 4' Sand Sand with lines less that, 4 SDI Silty sands, sand -silt mixtures 5 (nio'c than A(unbe linaboves plot above "A" line and plasticityl un, sieve fiqe� *) index greater than 7 SC Clx.e} sands, sand -clay mixtures Inorga,d, silts, -,,cry Fine solids, rock lc�j,- ino'g,nuic .it ' PI 14 or plot, be!.,, A" -line M L silty or clayey fare S­ds SILTS AND CLAYS Lnxgnuicdaspft., to ol.dilun (liquidsoil limit less than 50) 1—it PI > 7 site, plot, on or above 'A" line— C11 ill"s-icin y. grarell , cloys, sandy clays' silty clays' le,n, clays FINE GRAINED SOILS Organic Soil LL (oven dricd)/LL ;not dried) < 0.7, 5 n OL Or,,ai,.;c silts and cl silty clays of low 50'X. or more passes No. 200 plasticity sieve Inorganic soil pints Nola, "A" line NIH Inorganic sin" micaceous or dia�w'is fine sands or silts elastic silts SILTS AND CLAYS Inorganic soil ','lots no or above "A" title CH Inorganic c"ays ol,high plasticity, llitcla)s (iiqnid limit ;G a.- .,oil) Or6auic silts and organic clayi ofiligh I Organic Soil LL (aeon d­d)/LI_ (,lot dried) < 0.7, 5 OK plasticity Pest 1-lighl", organic I Primarily organic octuln. dark in color, and orignuic odor . - PT Peat, inuck and other Nighty organic juit, `Fines are those soil particles that pass the No. 200 sieve. For gava's and sands with between 5 and 12'.'/,l fines, use of dual symbols is required (I c. GW-GI. GW-GC. GP -GM. or GP -GC). **Iftlic plasticity index is between 4 and and it plots above the "A" line, then dual iyfliWs (i.e. CL-AIL) are required. li.cnuall 3.1,rlbalS (1.11 cl-ML) are required cqNsf:,TENCY co � I RE"IG I i I 1,A) D pt A ' 1,11( I 'YViQ P.I. It 1'0�% SI CIS POUT VERY SOF r 1 0 - 4 0- SOFT 1/4 - I _-I HIRM 112 - 4_s STIFF 1 -2 81 16 VERYSTIFF 16 -32 iWo 0"' Over - REUVIFIVE DENSI I'Y S `,NDS. l_;RA% I IS VN I) B LO %, -• NON 111,'Ilc sil-l" F()() VERYLOOSE 0 ' LOOSE 4.10 NIFI)IIJ."I DENSL 10 - 31) DENSE 30-50 VERY !)rNsr v,.-.r 50 CLASSIFICATIONS BASED ON PERCENTAGE OF FINES Less than 5%, Puss No. 200 (75nitil)sieve) G'W. GP, SW. SP More than 12`55 Pass N. 200 (715 irun) sieve GIM, GC. SM. SC Pass No. _200 (75 nun) sieve Borderline cltlssliicailon requiring use of'dual s.,mbols PLASTICITY CHART fine fraction ofcca—grained soils cH Aderberg L,,,cts P4 bcf-" dot"c'j,'res are bMifellilils c,'as4Wci.W­S requiring use c! dual sy"bc1s. c I Equatill of A.U­ P! (LL - 20) ­0L 20 as 43 be a.,1. Di Ming Notes: Number of blows of a 140-pound hammer .Palling 30- inches to drive a 2-inch O.D. (1-3/8-inch I.D.) split 1. Sampling and blow counts Types ofSaniplcs: X spoon (ASTM D1586). a. California Modiflied - MI'liber of bk),;Ns per Coot - Sample SP'f - Standard �t. Unconf.ned cornpressive strength in ttTrsisit It, as of a 140 pound liumnic! Falling 30 inches CA - Calzfornm Nlodo-led Penetration de(ernTinod by laboratory testing or approximated by b. Standard Penetration Test - number of blows per N -Nuclear Gauge the standard penetration test (ASTNI D15S6), pocket 12 inches of a 140 pound hamnici falling 30 PO -Pocket penctj oinctin, torvane, or visual Nbseration. inches GEMSUILM-ilm"S, IN[. HOMING LOG'BOWNG NO. 220 High Street r .TOR NO. L,07509-1 Sall Luis Obispo, CA 93401 PROJECT INFORMATION DRILLIN(I INFORMATION PROJI CT: Orcutt Specific Flan DRILL RIG: Mobile B-24 DRILLING LOCATION: See Figure 2, Site flan (Phase IV) HOLE DIAMETER: 4 Inches 1 DATE DRILLED: March 21, 2013 SAMPLING METHOD: SPT LOGGED BY: &SRC HOLE ELEVATION: Not Recorded n- Depth of Groundwater: Not Encountered Boling Terminated At:16.0 Feet Paue I of 7 SOIL DESCRIPTION U Z G g j W O O CLAYEY .SAND: dark brown, slightly moist, se medium dense CL +� ` • • SPT 30 54 SANDY CLAY: dark yellowish brown, moist, very stiff \ hard SPT 36 4s \...... i very stiff .\. - sn 28 33 CL — SANDY CLAY: light grayish brown, with gravel, moist . . ....... ...... . GeoSolutions, Inc. BORING LOG 220 High Street, San Luis Obispo, CA 93401 BOYdNG NO. 13-2 1021 West Tama Lane, Suite 105 JOB NO, -07509-1 Santa Maria, CA 93454 PROJECT INFORMATION DRILLING INFORMATION PROJECT: Orcutt Specific Plan DRILL RIG: Mobile: B-24 DRILLING LOCATION: See Figure 2, Site Plan (Phase 11) HOLE DIAMETER: 4 Inches DATE DRILLED: March 21, 2013 SAMPLING METHOD: SPT LOGGED BY: KRC HOLE ELEVATION: Not Recorded m Depth of Groundwater Not Kneountered Boring Terminated At: 15,0 Feet Page 2 of 7 SOIL DE'SC)UPTION 0 Z C L -12 -13 -14 -15 -16 -17 -18 -19 -20 SANDY CLAY: dark grayish brown, moist CL N very stiff SPT 26 46 CL. SANDY CLAY: olive brown, with gravel, moist . . 21� - CL SPT 12 16 SANDY CLAY: dark olive brown, with gravel, 1110ist, Very stiff hard SPT 36 43 GeoSolution.s, Inc. BORING LOG 220 High Street; San Luis Obispo, CA 93401 BARING NO. B-3 102I West Tama I.,alze, Suite I05 30B NO, SL07509-1 Santa Maria, CA. 93454 PROJECT INFORMATION DRILLING INFORMATION PROJECT: Orcutt Specific Plan DRILL. RIG: Mobile B-24 DRILLING LOCATION: See Figure 2, Site Plan (Prase 11) i IDLE DIAMETER: 4 Inches DATE DRILLED: March 21, 2013 SAMPLING METHOD: SPT LOGGED BY: KRC MOLE ELEVATION: Not Recorded Depth•of Grol.uidwater: Not Encountered Boring Terminated At:5.{1 Feet Page 3 ol'7 x w SOIL, DESCRIPTION n' x_ p 7, p l ti n v k% Q' f 0 U 14b z qU U (J `� _] -10 -I1 -12 -1.3 -14 -15 -16 -17 -18 -19 -20 BORING LOG"r GeoSolutions, Inc. 220 High Street, San Luis Obispo, CA 93401 130RING NO. B 4 1021 West Tama Lane, Suite 105 JOB NO. SL07509-1 Santa Maria, CA 93/154 PROJI CI.1NFORMATION DRILLING INFORMATION PROJECT: Ot•cutt Specific Plan DRILL RIG: Mobile B-24 DRILLING LOCATION: See Figure 2, Site Plan (Phase 11) HOLE DIAMETER: 4 belies DATE DRILLED: March 21, 2013 SAMPLING METHOD: SPT LOGGED BY: KRC HOLE ELEVATION: Not Recorded Depth -of GI•orindwater: Not Encountered BorinU'f'erminated At:15.0 Feet Page 4 of 7 w SOIL DESCRIPTION O Cam] w O �; a V ")LQ 0 _2 -3 -4 -5 -6 _g _9 -IO -I1 -12 -13 -14 -15 -16 -17 -18 -19 -20 GeoSolutions, Inc. BORING LOG j. 220 High Street, San Luis Obispo, CA 1) 340 1 BORING NO. B-5 0'21 West Tama Lane, Suite 105 JOB NO. SL07509-1 Santa Maria, CA 93454 PROJECT INFORMATION DRILLING INFORMATION PROJECT: orcutt Specific Plan DRILL RIG: Mobile B-24 DRILLING LOCATION: See Figure 2, Site Plan (Phase 1) HOLE DIAMETER: 4 Inches DATEDR11,LED: March 21, 2013 SAMPLING METHOD: SPT LOGGED BY, KRC HOLE ELEVATION: Not Recorded .v-, Deplh.of Groundwater: Not Encountered Boring Terminated At: 6.5 Feet Page 5 of 7 SOIL DESCRIPTION 0 z z F MR SANDY CLAY: very dark brown desiccation cracks to 24 inches CL SC -N SPT 81 145 CLAYEY SAND: olive brown, very dense, weathered claystone -10 -12 -13 -14 -15 -16 -17 -1s -19 -20 SANDY CLAY; dark brown, dry, soft CL SC J CLAYEY SAND: olive brown, slighly moist very dense, rock fragments SPT 50/6" i -1 -2 -3 -4 •5 -6 -7 -3 -9 -10 -ll -12 -13 •14 -15 -16 -17 -IS -19 -26 eoSolutions, Inc. ` 220 High Street, San Luis Obispo, CA 93401 1021 West Tama Lane, Suite 105 Santa Maria, CA 93454 BORING LOCH BORING NO. B-7 JOB NO, S1,07509-1 PROJECT INFORMATION DRILLING INFOR-MATION PROJECT: Oreutt Specific Plan DRILL RIG: Mobile. B-24 DRILLING LOCATION: See Figure 2, Site Plan (Phase III) HOLE DIAMETER: 4 Inches DATE DRILLED: Mareli 21, 2013 SAMPLING METHOD: SPT LOGGED BY: KRC HOLE ELEVATION: Not. Recorded !!e Depth of Groundwater: Not Encountered Boring Terminated At:6,0 Feet Page 7 of 7 WSOIL DFSCRIPTION w SANDY CLAY: very dark grayish brown, slightly moist desiccation cracks to 24 inches CH SC _ \ ,\ .. gab SPT 50/6" 1,15 ! 8.4 d 1 CLAYEY SAND: olive brown, weaQiered claystone, very dense C�-�o��l�tio�s� I��® BORING LOG 1� 220 High Street, San Luis Obispo, CA 93,101 BORING NO. B-8 1021 West Tacna Lane, Suite 105 JOB NO. SL07509-3 Santa Maria, CA 93454 PROJECT INFORMATION DRILLING INFORMATION PROJECT: Orcutt Expansion - Jones Parcel DRILL RIG: Mobile B-24 DRILLING LOCATION: See Figure 2, Site Plan IIOLE DIAMETER: 4 Inches DATE. DRILLED: April 11, 2014 SAMPLING METHOD: SPT and CA LOGGED BY: JK IIOLE I;I.EVATION: Not Recorded � Depth of'Groundwater; Not Encountered Boring Terminated At:10,0 feet Page I of 5 w SOIL DF.SCRIPTIOIJLQ ti a -1 ..2 -3 -h -5 _6 _7 -R -10 -ll -12 -13 -14 15 -16 -17 -18 _19. -20 69.5 27 GeoSolutions, Inc. BORING LOG Santa Maria, CA 93454 PROJECT INFORMATION DRILLING INFORMATION PROJECT: Orcutt Expansion -,Jones Parcel DRILL RIG: Mobile B-24 DRILLING LOCATION: See Figure 2, Site Plan HOLE DIAMETER: 4 Inches DATE DRILLED: April 11, 2014 SAMPLING METHOD: SPT m� Depth of Groundwater Not Encountered Boflug Terminated At: 5.,_; feet Paoe 2 of 5 10 SOIL DESCRIPTION UO 5- CLAY: black, with cobbles of serpcWfilite, dry very s(iff CL . ........... . FORMATIONAL MATERIAL: Serpentinite - Franciscan Formation, KJfs �-ec�Sc�l�.tinns, Inc. BORING ��c� 220 High Street, San Luis Obispo, CA 93401 BORING NO. Ii-10 102 1 West Tama Labe, Suite 105 JOB NO. SL07509-3 Santa Maria, CA 93454 PROJECT INFORMATION DRILLING INFORMATION PROJECT: Orcutt Expansion -,Jones Parcel DRILL RIG: Mobile B-24 DRILLING LOCATION. See Figure 2, Site flan HOLE DIAMETER: 4 Inches DATE DRILLED: April 11, 2014 SAMPLING METHOD: SPT LOGGED BY; JK HOLE ELEVATION: Not Recorded _v� Depth of Groundwater: Not Encountered Boring Terminated At: 5,0 feet Page 3 of 5 � ° SOIL DESCRIPTION U O � ° _� 5 O "` U 01 U LtJ �V 4 11 -I -2 -3 -4 -5 -6. -7 -g. c9 . -10- -12 SK �seoSolutions, Inc. BORING LOGImo, 220 High Street, San Luis Obispo, CA 93401 BORfNG NO. R-il 1021 West Tama Lane, Suite 105 JOB NO. SL07509-3 Santa Maria, CA 93454 PROJECT INFORMATION DRILLING INFORMATION PROJECT: Oreutt Expansion - Jones Parcel DRILL RIG: Mobile B-24 DRILLING LOCATION: See Figure 2, Site Plan HOLE DIAMETER: 4 Inches DATE DRILLED: April 11, 2014 SAMPLING METHOD: SPT LOGGED BY: JK HOLE ELEVATION: Not Recorded ir: Depth of Groundwater: Not Encountered Boring Terminated At: 5,o feet Page 4 of' 5 4 SOIL, DESCRIPTION z ti O O 4; O J { 0. a U w wv ? u -10 -12 ..13 -14 -15 -16 -17 -13 -19 -20 GeoSolutions, Inc . BORING LOG 2140 High Street, San Luis Obispo, CA 93401 BORING NO. B-12 1021 West Tama I.,ane, Suite 105 JOB NO, SL07509-3 Sawa Maria, CA 93454 PROJECT INFORMATION DRILLING INFORMATION PROJECT: Orcutt Expansion - Jones Parcel 1) R I L I, RIG: Mobile B-24 DRILLING LOCATION: See Figure 2, Site Plan HOLE DIAMETER: 4 Inches DATE DRILLED: April 11, 2014 SAMPLING METHOD: SPT LOGGED BY: JK HOLE ELEVATION: Not Recorded !r Depth of Groundwater: Not Encountered Boring Terminated At: 1 (),0 teet Page 5 of 5 SOIL DriSCRIP VION LQ w C) A CLAY: dark brown, di -VI stiff ct, S PT 30 36 FORMATIONAL MATERIAL: hard, Cyreywacke Sandstone - Franciscan Complex, Khg Geosolutions, Inc. BORING LOG (L 220 1 figh Street, San Luis Obispo, CA 93401 BORING NO, B-13 1021 West't'ama Lane, Suite 105 JOB N TO, SL07509-3 Santa Maria, CA 93454 PROJECT INFORMATION DRILLING INFORMATION PROJECT: Orcutt Expansion - Omel Parcel DRILL RIG: CME-55 DRILLING LOCATION: See Figure 2, Site Plan HOLE DIAMETER: 4 Inches DATE DRILLED: October 20, 2015 SAMPLING METHOD: SPT LOGGED BY: Pm HOLE ELEVATION: Not Recorded m Depth of Groundwater; Not Encountered Boring Terminated At: 10,S Feet Page I of SOIL DESCrUPTION Ul L) U SANDY CLAY: wry dart; brown, dry SC 7 CL-\7 A CLAYEY SAND: dark yellowish brown, dry hard SPT 42 48 CL CLAYEY SAND: light grayish brown, dry SPT 5014" hard 58 1 38.3 36 M -19 -20 ............... .... . .. . ........ . TRENCH LOG GeoSolutions, ble. q7 220 High Street, San Luis Obispo, CA 93401 TRENCH NO. -T-1 ane, Suite 105 1021 West Tama U JOB NO� ISLO7509-1 Santa Maria, CA 93454 PROJECT INFORMATION EXCAVATION INFORMATION PROJECT:Orcutt Specific Plan EXCAVATION METHOD: Baeldioe TRENCH LOCATION: See Figure2, Site Plan (PliaselV) BUCKET SIZE: 18 Inches DATE EXCAVATED: March 20,2013 SAMPLING METHOD: Bag LOGGED BY: 1,CRC TRENCII ELEVATION: Not Recorded � Depth. of Groundwater: Not Encountered Trench Terminated At: 15.0 Feet Page I of 6 All Q SOIL DFSCR.fPTION LQ 0 0 - 1 -2 -.3 .4 -5 -6 -7 -8 -9 -10 -11 -12 -13 . I'l -20 CLAYEY SAND: dark brown, sliglitly rmoist, loose medium dense SC PP PP 2h . 2 SANDY CLAY: dark yellowishbrown, inotited orange/dark brown, very stiffto hard PP fi 5 caliche, hard X �. reoSol tions, Inc. TRENCH I,O 220 High Street, Salt Luis Obispo, CA 93401 TRENCH NO. T-2 1021 West Tama Lane, Suite 105 JOB NO. SL07509-1 Santa Maria, CA 93454 PROJECT INFORMATION EXCAVATION INFORMATION P ROJECT:Orc Litt Specific Plan EXCAVATION METHOD: Backhoe TRENCH LOCATION: See Figure 2, Site Plan, (Phase IV) BUCKET SIZE: IS Inches DATE EXCAVATED: March 20, 2013 SAMPLING METHOD: Bag LOGGED BY: ICRC TRENCH ELEVATION: Not Recorded m: Depth of Groundwater: Not I?,ncountered Trench Terminated At: 15.0 Feet Page 2 of 6 Q SOIL DFSCRIPTION _ U U C7 -7 -10 -12 -l3 -ia -15 -16 -17 -I8 -19 -20 I, ��eoSo utious9 Inc. TRENCH �a� TRENCH NO. . 22.0 Tligh Street, San Luis Obispo, CA 93401 T-3 �- 1021 West Tama Lane, Suite 105 JOB NO, L07 09— Santa ivlaria, CA 93454 PROJECT INFORMATION EXCAVATION INFORMATION PROJECT:Orcutt SPecifle Plan EYCAVATtON METHOD: Backhoe `FRENCH LOCATION: See Figure 2, Site Plan, (.Phase 1) BUCKET SIZE: 18 Inches DATE EXCAVATED: March 20, 2013 SAMPLING METHOD: Bag LOGGED BY: KRC TRENCII ELEVATION: Not Recorded m Depth -of Groundwater: Not Encountered Trench Terminated At: 14.5 Feet Page 3 of 6 0 a r- W SOIL DESCRTI MON O q -1 -2 _3 -`i -5 -6 -7 _8 -9 -10 -1 ] -12 -13 -14 -15 -16 -M7 -l8 -M9 -20 j eU olutions, Inc® TREK x LOG 220 High Street, San Luis Obispo, CA 9340I I'I:.) NCII NO. Y —4 1021 West Tama Lane, Suite ] 05 SOB NO, SL07509-1 Santa. Maria, CA 93454 PROJECT INFORMATION EXCAVATION INFORMATION PROJECT;nrcuttSpecific flan EXCAVATION METHOD: Bacichoe `FRENCH LOCATION: See figure 2, Site Plan (Phase I S I } BUCKET SIZE: 18 Inches DATE EXCAVATED: March 20, 2013 SAIvIPLTNG METHOD: Bag LOGGED BY: KRC TRISNCH ELEVATION: Not Recorded m Depth of Groundwater: Not Encountered Trench Terminated At: 15.0 Feet Page 4 of 6 WSOIL DESCRIPTION19 O S� W 4 -1 -2 -3 -4 -5 -6 -7 -9 -lo -il -12 -13 -14 -15 -16 -17 -1S -19 -20 -10 -12 -13 -14 -15 -16 -17 -19 -19 -20 GeoSolutions, Inc. TRENCH LOG 220 High Strect, Sail Luis Obispo, CA 93401 TRENCH NO, T-5 1021 West Tama. Lane, Suite 105 JOB NO. SL07509-1 Santa Maria, CA 93454 PROJECT INFORMATION EXCAVATION INFO KMAT'f ON PROJECT:01'eutt Specific P1,111 EXCAVATION METHOD: Baeldioe TRENCH LOCATION: See Figure 2, Site Plan (Phase 111) BUCKET SIZE: 18 Inches DATE EXCAVATED: March 20,2013 SAMPLING METHOD: Bag LOGGED BY: KRC TRENCH ELEVATION: Not Recorded !!r: . Depth of Groundwater: Not Encountered Trench Terminated At: 4.0 Feet Prue 5 of 6 4� SOIL MCMPTION 15 �11 ,aC g� 0 CLAYEY SAND: yellowish brown, with gravel, dry, sc loose AA^A OA A4Ad A BFIDIWK: reddish brown, weatheredAAAA Chert, fractilred, dry AA AAA A A AAAA AA An A A A A A AAAAA A A A A A A A A A hard to dig A A A A A A A! A A AAA A A -5- -6 -7- -8- -9- -to - ..] I -- -12- -13 - -14- -15 - -16- -17- -18- -19 -20 TRENCH LOG GeoSolutions, Inc. 2120 High Street, San Imis Obispo, CA 93401 TRENCI-1 NO. -T-6 1021 West Tama Lane, Suite 105 JOB NO. -SL07509-1 Santa Maria, CA 93454 PROJECT INFORMATION EXCAVATION INFORMATION PROJECT; 01-c"tt Specific PIH" EXCAVATION METHOD: Bulkhoe TRENCH LOCATION: See Figure 2, Site Plan, (Phase 1.1) BUCKET SIZE: 18 Inches DATE EXCAVATED: March 20,2013 SAMPLING METHOD: Bag LOGGED BY: K.RiC FILEVATION: Not Recordet] ir Depth of Groundwater: Not Encountered Trench Terminated At: 15,0 Feet Page 6 of'6 SOIL DESCWTION u 0 0 Lr -T 0 CLAYEY SAND: reddish brown, ,,',Iigllllyjlloist, loose SC CL SANDY CLAY: dark olive brown, moist, firm I'P/X 1:� (2-4 116.2 11 11 CL SANDY CT.,AY: olive brown, moist, hard Pl'/X '5 SC CLAYEY SAND: olive brown, with gravel, caliche, ftactured weathered serpentinite bedrock, moist, very dense . x- cobbles 3 to 8 inches in diameter eoSolutions, Inc. 'DRENCH LOG L. 220 High Street, San Luis Obispo, CA 93401 TRENCH NO. r-7 1021 West Tama bane, Suite 105 roh NO,SL07509-8 = Santa Maria, CA 93454 PROJECT INFORMATION EXCAVATION INFORMATION PROJECT:Orcutt Area Specific Plan - Pratt Property EXCAVATION MET'I-101): Roackhoe TRENCH LOCATION: See Figure 2, Site Plan BUCKET SIZE: 24 Inches DAT EXCAVATED: March 30 & June 8, 2016 SAMPLING METHOD: Bulk Bag LOGGED BY: JK TRENCH ELEVATION: Not .Available Y Depth of Groundwater: Not Encountered Trench Teiminated At: 5 Feet Page I of 7 w n r SOIL DESCRIPTION Oa r r = ? u O o a a -X o� r 'e �o LQ Q o z ffn -12 -13 -14 -Is -16 -17 -19 -19 -2.0 - - --------- GeoSolutions, Inc. TRENCH LOG 220 High Street, San Luis Obispo, CA 93401 TRENCH NO. T-8 1021 West Tama Lane, Suite 105 JOB NO. SL07509-8 Santa Maria, CA 93454 PROJECT INFORMATION EXCAVATION INFORMATION PROJECT:0rcutt Area Specific Plan - Pratt Property EXCAVATION METHOD: Backhoe TRENCH LOCATION: See Figure 2, Site Plan BUCKET SIZE: 24 Inches DATE EXCAVATED; March 30&June 8,20I6 SAMPLING METHOD: Bulk Bag LOGGED BY: I I( TRENCI I ELEVATION: Not Available w- Depth of Groundwater: Not Encountered Trench Terminated At: 2.5 Feet Page 2 of 7 SOH- DESCRIPTION Q Aw ;5 —j -12 -13 -14 -15 -16 -17 -18 ..19 -20 FAT CLAY, black, sandy, stiff CH Cl, SANDY CLAY: brown, caliche, very stiff ....... .................. ............. ................ j_ eoSolutions, Inc. 'TRENCH LOG 220 High Street, San Lilts Obispo, CA 93401 TRENCH NO. T-9 1021 West Tama lane, Suite 105 JOB NO. SL07509-5 Santa Maria, CA 93454 PROJECT INFORMATION EXCAVATION INFORMATION PROJECT:Orcutt Area Specific Plan - Pratt Property EXCAVATION METHOD: Backhoe TRENCH LOCATION: See Figure 2, Site Plait BUCKET SIZE: 24 Inches DATE EXCAVATED: March 30 & ,June 8, 2016 SAMPLING METHOD: Bulk Bag LOGGED BY: JK TRENCII ELEVATION: Not Available s Depth of Groundwater: Not Encountered Trench Terminated At: 2,5 Feet Page 3 of 7 SOIL (A"SCRIPI'ION y 0� t S} w c a U° t u O a aw q -10 -12 -13 -14 -15 -16 -17 -18 -19 -20 G' eoS lutionsy Inc. TRENCH LOG •'' 220 High Street, San Luis Obispo, CA 93401 TRENCH NO, rj'—iQ 1021 West Tama Lane, Suite 105 JOB NO SL07509-8 Santa Maria, CA 93454 PROJECT INFORMATION EXCAVATION INFORMATION PROJEC'I':0reutt Area Specific Plan - Pratt Property EXCAVATION METHOD: Baekhoe TRENCH LOCATION: See Figure 2, Site Plan BUCKETSIZE, 24 Inches DATE EXCAVATED: Mareh 30 &June 8, 2016 SAMPLING METHOD: Bulk Bag 1'OGGED BY: JK "f'R; NCH ELEVATION: Not Available i Depth of Groundwater: Not Encountered Trench Terminated At: 3 Feet Page 4 of "1 k LL) •i SOIL DESCRIPTION U Q W '� C r V r � .o � V � 4 �, y n ti a U C -10 -11 -12 -13 -ICI -15 -16 -17 -18 -19 _20 GeoSolutions, Inc. TRENCH LOG 2 -fic, 'A 93401 20 1 li Street, San Imis Obispo, C TRENCH NO, T-1 I 1021 West Tama Lane, Suite 105 JOB NO.SL07509-8 Santa Maria, CA 93454 PROJECT INFORMATION EXCAVATION INFORMATION pRc)j[-.c'I':0rcutt Area Specific Plan - Pratt Property EXCAVATION METHOD: Backhoe TRENCH LOCATION: See Figure 2, Site Plait BUCKET SIZE: 24 Inches DATE EXCAVATED: March 30 &June 8,2016 SAMPLING METHOD: Bulk Bag LOGGED BY: JK TRENCH ELEVATION: Not Available m Depth Of (31'OUndwater: Not Encountered Trench Terminated At: 4.5 Feet Page 5 of 7 L7 SOIL DESCRIPTION 0 -10 -12 -13 -14 -15 -16 -17 -18 -19 -20 FILL: loose, (tjy Fill CH CL FAT CLAY: black, sandy, stiff SANDY CLAY: gray/green, hard j eoSolutions, Inc. TRENCH LOG 220 High Street, Sall I..,uiS Obispo, CA 93401 IRL;NCH NO. 'T- 2 - 1021 West Tama Lane, Suite 105 JOB NO, Sj,47509-$ Santa Maria, CA 93/154 PROJECT INFORMATION EXCAVATION INFORMATION PROJECT:dreutt Area Specific Plan - Pratt Property EXCAVATION METHOD: Backhoe 'I RI NCH LOCATION: See Figure 2, Site Plan BUCKET SIZE: 24 Inches DATE EXCAVATED: March 30 & June 8, 2016 SAMPLING METHOD: Bulk Bag LOGGED BY: JK TRENCH ELEVATION: Not Available s Depth of Groundwater: Not Encountered Trench Terminated At: 5,5 Feet Page 6 of 7 SOIL DESCRIPTIONLQ LQ -10 -12 -13 -14 -15 -16 -17 -18 -19 -20 GeoSolutions, Inc. TRENCH LOG 220 High Street, San I-Alk Obispo, CA 93401 TRENCH NO. T- 12 1021 West Tama Lane, Suite 105 JOB NO, S1,07509-8 Santa Maria, CA 93454 PROJECT INFORMATION EXCAVATION INFORMATION j)ROjECT:0rcutt Area Specific Plan - Pratt Property EXCAVATION METHOD: Backhoe TRENCH LOCATION: See Figure 2, Site Plan BUCKET SIZE: 24 Inches DATE EXCAVATED: March 3O&June 8,2016 SAMPLING METHOD: Bulk Bag LOGGED BY: JK TRENCH ELEVATION: Not Available ir Depth of Groundwater Not Encountered Trench Terminated At: 7 Feet Page 7 of 7 S011, DESCRIPTION C-0 z M4 -4 -10 -20 FAT CLAY: black, Sandy, SIM' C14 Cl, SANDY CLAY: gray/green, hard kPPENDIX B Laboratory Testing Soil Test Reports Geo5vlutions, mr. LABORATORY TESTn- G This appendix includes a discussion of the test procedures and the laboratory test results performed as part of this investigation. The purpose of the laboratory testing is to assess the engineering properties of the soil materials at the Site. The laboratory tests are performed using the currently accepted test methods, when applicable, of the American Society for Testing and Materials (ASTM). Undisturbed and disturbed bulk samples used in the laboratory tests are obtained from various locations during the course of the field exploration, as discussed in Appendix A of this report. Each sample is identified by sample letter and depth. The Unified Soils Classification System is used to classify soils according to their engineering properties. The various laboratory tests performed are described below: Expansion Index of Soils (ASTM D4829-03) is conducted in accordance with the ASTM test method and the California Building Code Standard, and are performed on representative bulk and undisturbed soil samples. The purpose of this test is to evaluate expansion potential of the site soils due to fluctuations in moisture content. The sample specimens are placed in a consolidometer, surcharged under a 144-psf vertical confining pressure, and then inundated with water. The amount of expansion is recorded over a 24- hour period with a dial indicator. The expansion index is calculated by determining the difference between final and initial height of the specimen divided by the initial height. Laboratory Compaction Characteristics of Soil Using Modified Effort (ASTM D1557-07) is performed to determine the relationship between the moisture content and density of soils and soil - aggregate mixtures when compacted in a standard size mold with a 10-lbf hammer from a height of 18 inches. The test is performed on a representative bulk sample of bearing soil near the estimated footing depth. The procedure is repeated on the same soil sample at various moisture contents sufficient to establish a relationship between the maximum dry unit weight and the optimum water content for the soil. The data, when plotted, represents a curvilinear relationship known as the moisture density relations curve. The values of optimum water content and modified maximum dry unit weight can be determined from the plotted curve. Liquid Limit, Plastic Limit, and Plasticity Index of Soils (ASTM D4318-00) are the water contents at certain limiting or critical stages in cohesive soil behavior. The liquid limit (LL or WL) is the lower limit of viscous flow, the plastic limit (PL or WP) is the lower limit of the plastic stage of clay and plastic index (PI or IP) is a range of water content where the soil is plastic. The Atterberg Limits are performed on samples that have been screened to remove any material retained on a No. 40 sieve. The liquid limit is determined by performing trials in which a portion of the sample is spread in a brass cup, divided in two by a grooving tool, and then allowed to flow together from the shocks caused by repeatedly dropping the cup in a standard mechanical device. To determine the Plastic Limit a small portion of plastic soil is alternately pressed together and rolled into a 1/8-inch diameter thread. This process is continued until the water content of the sample is reduced to a point at which the thread crumbles and can no longer be pressed together and re -rolled. The water content of the soil at this point is reported as the plastic limit. The plasticity index is calculated as the difference between the liquid limit and the plastic limit. Particle Size Analysis of Soils (ASTM D422-63R02) is used to determine the particle -size distribution of fine and coarse aggregates. In the test method the sample is separated through a series of sieves of progressively smaller openings for determination of particle size distribution. The total percentage passing each sieve is reported and used to determine the distribution of fine and coarse aggregates in the sample. GeOS0lUtiO[i5, INC. Density of Soil in Place by the Drive -Cylinder Method (ASTM D2937-04) and Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass (ASTM D2216-05) are used to obtain values of in -place water content and in -place density. Undisturbed samples, brought from the field to the laboratory, are weighed, the volume is calculated, and they are placed in the oven to dry. Once the samples have been dried, they are weighed again to determine the water content, and the in -place density is then calculated. The moisture density tests allow the water content and in -place densities to be obtained at required depths. GOGFIDIUVO115, INC. ( ei�S[�lutio �s, Inc.:.:... :. SOILS REPORT (805) 543-�8539 Project: 01'CUtt A e3 Specific Plan Date Teszcd: March 28, 2013 Client: Ambient Communities Project#: SL_07509-1 ^ Sample: T-2 (?) di 2-3' De 2.0 to 3.0 Feet Lab P: 15218 Location: `l'-2 Sample Date: March 20, 2013 Sampled By: I{RC/SP Soil Classification Labor,,gory Maximum Density ASTM D2487-06, D2488-06 w ASTM D1557-07 Result: Very Dark Grayish Brown Sandy CLAY 113,5 Specification: CL 113.0 Sieve Analysis ASTM D422-63R02 112,5 Sieve Percent Project w 112,0 Size passhig Specifications 3" 2" 1 1/2" 3/4" No.4 99 No.8 97 No. 16 92 No.30 86 No.50 78 No. 100 67 U 111.0 R 110.5 --- h 6110.0 109.- — 109.0 108.5 0,0 5.0 10.0 15.0 Water Content, % 20.0 Said E2uivalent:Cal217i 06/2011; Mold 1D n/a IMold Diameter, ins. 4,00 1:. 2 SE 3' No. of La Hers 5 1weight o[ Ramnter, lbs. 10.00 4 No. of•131ows 25 Plasticity Index ASTN1 D4318-05 Liquid Limit: 33 Estimated S pecific iravit for 100% Saturation Curve = 2.45 Plastic Limit: 17 Trial # 1 2 3 4 Plasticity Index: 16 Water Content: 10.5 12.8 16.4 )Expansion Index ASTM D4829-08 Dry Density: 110.9 113.0 109,0 Maximum Dry Density, pcf: 113.0 Opti num Water Content, %: 13.0 Expamsion Index: 40 Expansion Potenl.ial: Low Initial Saturation, %: 50 :`Moisture-Densit:ASI'N1D2937-04"Moistuie:ContentASTMD22I6.05 `Sam le Depth 11 Water:Conteiit % Dry Density o <:RelativeDeiisity: Sa n le Description .7777777, ME (;cosolutions, Tic. ° SOILS REPORT o05.) 5C5 39 Prnierr Orcutt Area Soecific Plan _ Date Tested: Aril 1, 20I3 _Ambient Communities ,-,vjcu� f T-2 u, 5-6' Depth: 5.0 to 6.0 Peet Lab 9: 1525 T-2 Sam ie. Date: March 20, 2013 rya aa-8539 Project; Orcu Lt Area Specific Plan Date Tested: April 1, 2013 Client: Ambient Communities Project SL07-509-1 Sample: 1,-3 (C)i 3 Depth: 10 Feet Lab #: 15218 Location: T-3 Sample Date: March 20, 2013 Sampled By: KRUSP Soil Classification La.b0A.tory.Ma.ATnU.m 1411S.W.. ASTNII D2487-06, D2488.06 Result: Very, Dark Grayish Brown Sandy Fat CLAY Specification: CH Sieve Analysis 1.0 ASTMD422-63RO2 Sieve Percent Project 'd 0.8 Size Passing Specifications .3 -2 :0,6 1 1/2" 0.4 7:- lit 3/4" No. 4 No. 8 0.0- No. 16 .0.0 .02 .0.4 0.6 .No, 30 No. 50 Water Content,% No. 100 No.200 S1.5 Equivalent Cal 217 (06/2011): SE Mold ID: wjns; Mold Diarnete A00 4 No. of Layers 5 IWei of Rammer.% 000 J!"Insticity Index ASTNI D4318-05 Liquid Unit: 61 EstimOed.Spc dfi0'2EL Mfoni 0 Plastic Unit: 15 TrIal.4 - Al 4 Plasticity index: 46 Water Content: Expansion Index D!x Densi ASTM D4829-08 Maximum DryDen Vd, 4Y� Expansion Index, 94 dipflinl6mmajor.Qok4oni,:%; Expansion Potentiate High initial Saturation, %: 50 ]Moisture-Densi ASTM D2937-04,Voisture Content ASn4 D2216-05 Sample Depth (,2): Water Cop tent (%) Dry Density (pbf) Relative DensjL Sample Description :..-.7777777 I �:177777777771 7enort Bv: Aaron Eichman B 3 Soil Classification I a1}oraturylVMaximtim Density ASTMD2487-06,D2488-06 _. �5'J'A4D1557.07. Result: Light Brownish Gray Sandy CLAY -- Specification: CL Sieve Analysis i3O -. .-•-.-— _-- _-- ASTM D422-63R02 Sieve Percent Project .. 0.8 _ Size PassinR Specifications 311 0,G 2 11 r lrxl i 3/411 o.z No.'4 . No. 8 0.0 No, 16 0:0 0.2 0.4 0.6 0.8 No."3 0 No, 50 Water Content, No::100 No, 200 'Sand.Eq uivalent Cal 217 '(06/2011): l SE` 2 Mo1d.TD ` nls Mold Diameter, ins. 4.00 3 No. of La ers 5 1 WOkbt of Rammer, lbs. 10.00 4 No. of Blows 25 Plasticity Index ASTM D4318-05 Liquid Limit 48 Estunated Specific Gravity for, 100%'Sattnation Curve _ Plastic Limit: 19 Trial #! =. l 2 3 4 Plasticity Index: 29 Water Content; Expansion Index Dt Densi ; ASTM D4829-08 Maxiniuin Dry Density,..pef;, Expansion Index; 81 OptiniuM.Water {Omen- %:.. Expansion Potential: Medium ' Initial Saturation, %: 50 Moistare:Density-ASTM D2937-04 Moisture Content ASTMD2216-05 Sample : Depth'(8) Water Content`(%) : Dry D] nsi ' pcf Relative Density: Sample Description ":.777--7777777 64 Gc.ci5�i1.►zfiozis, laic. SDIlsP(1R'!' . (SQS}.543-8539 ?roiect: Orcutt Area Specific Plan Date Tested: March 26, 2013. lient: Ambient Communities Project #: SL07509 l Sample: T-6 0,T De the 2.0 Feet Lab #: ISM ,ocmiow T-6 Sam le Date: March 20, 2013 _ - Sampled B I4RC/SP Soil Classification Laboratory-Maximuin Density ASTivI D2<157-06, D2I88-UG ASTM p1557 07 Result: Dark Olive Brown Sandy CLAY Specification: CL Sieve Analysis ASTM D422-63R02 Sieve Size Percent Passing Project Specifications 3" 2" 1 1 /z 1 r, 3/4" No.4 98 No.B 96 No. 16 91 No.30 85 No.50 75 No.100 62, No.200 53.2 Sand E<i uivalent Cal 21.7406/2011) SE 117.0 116.0 115.0 0 114.0 a. y 113,0 _ ,N 11111 Q 111.0 110.0- 109.0 t_ 10&0 0.0 5.0 10.0 15.0 20.0 Water Content, % 2: Mold ID n/a .3`; Y No. of Lavers 5 4 No. of Blows 25 Plasticity Index ASTM D4318-05 Liquid Limit: 29 jEstiiiiated S ecific Gravity for 100% Plastic Limit: 18 ITrial # 1 Plasticity Index: 11 Water Content: 9.2 B5 Diameter, ins. ,1.0O it of Rammer. lbs, 10,00 2.5 3 4 CxeoSoluliorts, Xrac:.' SOILS RPUR ($11� 543-SS39 Pri>iect Orcutt Area Specific Plan Date Tested: iMarch 26, 2013 i :;lient: Ambient Communities Project 91: SL07509-1 Sample: T-6 @ 5- Depth: 5.0 Feet Lab #: 15218 { Location: 'f-6 Sample .Date: Mardi 20, 2013 I Sainnted Bv: KRC/SP ; Soil Classification L b6rk6r M. axirnum.Density ASTM D2487-06, 1)2488-06 AST- M 1A557-07 Result: Olive Brown Sandy CLAY 12 ' %J Specif eation: CI, Sieve Analysis .1.0 ASTM D422-63R02 Sieve Percent Project U 0,8:. Size Passing S ecifica(ions A .... ; y; 3- 'q 0.6 1 1/2' 0 4. 1 , R 3/4„ 0.2 F. No. 4 No. 8 00 . No:16 0:0 0.2 0.4 0.6 No: 30 :No. 50.:. Water Cuutent, No 100 No.200 Sand Elquivulent:Cal217' 06/201I :: 1 SF': 2 ;' Mold 11). ' iVa Mold Dia,nctcr,'ins. 4:00 3 E No. of Layers Wei ht:raf Ram ihs ..' 10.00 4 No, of Blows 25 Plasticity Index ASTM D4318-05 Liquid Limit; 33 Bstirnated Sneoitic Gravo for 100%Sahtration Curve. PlasticL'unit: 19 Trial# l 2 3 4 PlasticitvIndex: j 14 Water Content:: ;•1 � Expansion Index DtTDensi : ASTM D4829-08 Maxi6w(n My..Derisity, pcf; Expansion Index: j 44 C tmwn Watcr:uontent, °/o: Expansion Potential: Low hiitial Sawration, %: 50 Moisture-Density:ASI-M D2937-04,'Moisture Content ASTM D2216-05 Sample Depth {ft Water Content No) .Dry Density pcf) Relative Density'm Sam le Description B6 G�riSolutaons; in[, 00o: �13-8539 'roicct; Orcutt Area Specific Plan Date Tested: March 29, 2013 -lient: ambient. Communities Project 4: SL07509-1 Sample; B 3 (R 5-10' De the 5.0 to 10.0 Feet Lab #: 15218 ocatian: B-3 Sam nle. Date: IvIm-ch 21, 2013 Sampled By: ICP�CrSY B7 (,cosolutionS, SOILS RI+i'Ulti' ). Project: Orcutt Axca Specific Plan --- Date Tested: \larch 29, 2013 Client: Ambient Communities 111-o'ect #: SL07)5(}9-1 5atrr le: )3-I �u 1-Y Depth: 1.0 to 3,0 poet Lab #: 15218 i,,,mmk IVTarch 21. 2013 1: Ma1dID 7a _ Mold `Diameter,'ins. 4;00 j No. of Layers 5 lweolt of Ninriier, lbs. 1,0.00 N❑. o1'.Blo�,'s 25 Plasticity Index k S C. l D4 18-OS ti 3 56 . Estunated SUecifle.Gravi for 100% Sattirkloie Curve 138 DUNS r TVIf3ISTUHE= TTI; D2{)37=04 GE:6s.61ut1Pnfi; lric, 8 5 MUISTLTIM'.CONUNT, 2.116-05 -. Project: Orcutt Area Specific Plan Date Tested: March 28, 2013 Client: Ambient Communities Project 9: SL07509-1 Sample 'R: Depth: Lab #; 15218 Location: See Below Sample Date: March 21, 2013 Sampled By: KRC/SP Depth Below Percent of Tu-Situ Optimum 1Vatcr o tinium Soil Description Snmplc Lowest Adjacent Content eut Content t Grade A"foisture B-1 5.0 17.2% Dark Brown Sandy CLAY B-1 B-1 B-2 B-2 B-2 B-3 10.0 15.0 5.0 10.0 15.0 5.0 165% 202% 15.1 % 16.6% 11.5% 11. 3% Dark Brown Sandy CLAY Dark Brown Sandy CLAY Olive Brown Sandy CLAY Olive Brown Clayey SAND Dark Olive Brown Clayey SAND with Gravel Olive Brown Sandy CIA A Y B-4 B-5 5.0 5.0 18.3% 7.0% Olive Broom Sandy CLAY Light. Olive Brown Clayey SAND B-6 B-7 P-3 5.0 5.0 5.0 9.5% 12.2% 7.0% Light Olive Brown Clayey SAND Olive Brown Clayey SAND LightYellowish Brown Sandy CLAY Comments: Report By: Aaron L""^ ichman B9 5C1TIa;s:RT`�'Ql7"�' :.. : Project: Orcut(. Expansion Area Addition Date "Tested: A grit 21; 2014 Client: Project #: SL07509-3 Sample: A De )tla: Lab 4: 15653 Location: B-8 Sample Date: April 11, 2014 S'mmnled Bv: JK Renort Bv: Aaron Eichman Bl Geosol r.Limis, Inc...PARTICLE-SIZE ANALYSIS HEI'ORT. ^' . (805) 54378a39 Project: Orcutt Expansion Area Addition Date Tested: 4/25/2014 :;lient: Project #: SL07509 3 Sample #: A Depth: Lab 4: 15653 Location: B-8 Sample Date: 4/1 I/2014 Mff-rinl. Black Sanclv CLAY Sampled By: J-kl Sieve Analyis AS`I'1M D422-07 Project Sieve Size Percent Passing Specifications 2-in. 100 1 1/2 in. 100 1-in, 100 Hydrometer Analysis ASTM D422-07 Project Sieve Size (lmn) Percent Passing Specifications 0.0319 60,0 0,0204 56.0 0.0119 50.0 3/4-in, 100 0.0085 46.0 1/2-in. 100 0,0660 44.0 3/8-in, 100 0.0030 39.0 No. 4 (4.75-mm) 100 0.0013 31.0 No. 8 (2.36-mm) 99 No. 16 (1.18-1nm) 98 No. 30 (0.85-mm) 96 No. 50 (0.304 ,-mn) 90 No. 100 (0.150-1mn) 79 No. 200 (0.075-min) 1 69.5 100.0 90.0 80.0 70.0 r 60.0 ,N 50.0 P, 40.0 U 30.0 20.0 10.0 00 1000 100 Sand % = 30 4.75 nim .075 lrnm 002 mni 10 1 0,1 Grain Size, mm Silt % = 35 0.01 0.001 0.0001 Clay % = 35 Cobbles Gravel Sand Silt Clay 75-3001nm 4,75-75mm 075nim - 4.75mni .002-.075mm < 0.002 mm C:� ii68olkttious, .bic Project: hTid Site Orcutt Expansion Client: B- Soil Classification ASTN4 D2487-06, D2488-06 Result: Veiy bark Brown Clayey SAND Sieve Analysis ASTM D422-63R.02 Sieve I Percent I Project 3" 2" 1" 3l4" No.4 97 W 8 9,1 No. 16 91 No.30 88 No.50 79 No. 100 1 66 No.200 1 38.3 ISIOILa )Eiis['UR i'.:.:: := ;::. <::; . (805) 543-8539 . Date Tested: October 21, 2015 Project ]l SL07509-6 0 to 3.0 Feet Lab #: 16291 SarnMe, Date: October 21, 2015 131 i:. \ IIII.a: � .. ..-�rO.gCk __-.3.q _�.t' 805 543 8539: Project: Orcutt Specific Pratt Dale Tested: June 18, 2016 Client: Project fl: SL07509-8 Sample: A Deptli: _ i.0 Foot Lab 4: 10542 Location: T-7 Sample Datc: June 9, 2016 Sampled By: 11i 'foil Classification] abr►r'itnr I41u4fnurwDcpsity ASTM D2487, D2488 ASTM DIS57 ILesult: Black Sandy Fat CLAY k. Specification: CH 1 si p An4ils — _ AS.��1�2 _• � . 8 0: -- -... Silty J wificationJ i y 0.4 . �14" No 8' j I _ Nra. 16 . z,r <rn - %0 D,2 fl>4 0.6 0.8 1.0 ?.2 - water Conten#°ro NQ, l�0 Sued E00yawyn. CA h I ..... - ---. 2 1v c+i;[.Ii) nla Mold Diumerei ins. 4.00 3 No. Of•La ers . 5 Wei tt of Ratumtr, lbs. 10.00 4 Nn..ofBIGIvs Plasticity Index ASTM D4318 Liquid Limit: 56 Issti:nated'S eciiic GiaVr .far i00%:5aturation Cutve =; Plastic Limit: 16 `i'rial.# 1 ' 2 ..3: 4 Plasticity Index: 40 Wator Content: Expansion Index Dry Density: ASTM D4829 Maxiw4m Dry Density; p�f: Expansion Index: 96 Op6murn Water Conte:=_I, `/ Expansion Potential: High Initial Saturation, %: 50 Moisture -Density A5TIVII437��stgre Content�rtvJ-u22i6 Sample De th (fI) Water. Content (%) I}` oensi" �kpcYRelative Density S.am Ie. Tlescri rtion 77 Ro ott By: Aaron Fichman BI B2 =1PPYINIDR C Seismic Hazard Analysis Design Map Summary (SEAOC, 2018) GeoSolutions, INC. SEISMIC HAZARD ANALYSIS According to section 1613 of the 2016 CBC (CBSC, 2016), all structures and portions of structures should be designed to resist the effects of seismic loadings caused by earthquake ground motions in accordance with the ASCE 7: Minimum Design Loads for Buildings and Other Structures, hereafter referred to as ASCE7-10 (ASCE, 2013). Estimating the design ground motions at the Site depends on many factors including the distance from the Site to known active faults; the expected magnitude and rate of recurrence of seismic events produced on such faults; the source -to -site ground motion attenuation characteristics; and the Site soil profile characteristics. As per section 1613.3.2 of the 2016 CBC, the Site soil profile classification is determined by the average soil properties in the upper 100 feet of the Site profile and can be determined based on the criteria provided in Table 20.3-1 of ASCE7-10. ASCE7-10 provides recommendations for estimating site -specific ground motion parameters for seismic design considering a Risk -targeted Maximum Considered Earthquake (MCER) in order to determine design spectral response accelerations and a Maximum Considered Earthquake Geometric Mean (MCEG) in order to determine probabilistic geometric mean peak ground accelerations. Spectral accelerations from the MCER are based on a 5% damped acceleration response spectrum and a 1% exceedance in 50 years (4975-year return period). Maximum short period (Ss) and 1-second period (SI) spectral accelerations are interpolated from the MCER-based ground motion parameter maps for bedrock, provided in ASCE7-10. These spectral accelerations are then multiplied by site -specific coefficients (Fa, F ), based on the Site soil profile classification and the maximum spectral accelerations determined for bedrock, to yield the maximum short period (SMs) and 1-second period (SMi) spectral response accelerations at the Site. According to section 11.2 of ASCE7-10 and section 1613 of the 2016 CBC, buildings and structures should be specifically proportioned to resist design earthquake ground motions. Section 1613.3.4 of the 2016 CBC indicates the site -specific design spectral response accelerations for short (SDs) and 1-second (SDI) periods can be taken as two-thirds of maximum (SDs = 2/3*SMs and SDI = 2/3 * SMi). Per ASCE7-10, Section 21.5, the probabilistic maximum mean peak ground acceleration (PGA) corresponding to the MCEG can be computed assuming a 2% probability of exceedance in 50 years (2475- year return period) and is initially determined from mapped ground accelerations for bedrock conditions. The site -specific peak ground acceleration (PGAM) is then determined by multiplying the PGA by the site - specific coefficient Fn (where FI, is a function of Site Class and PGA). Spectral response accelerations, peak ground accelerations, and site coefficients provided in this report were obtained using the web -based Seismic Design Maps tool available from the Structural Engineers Association of California (SEAOC, 2018). This program utilizes the methods developed in the 1997, 2000, 2003, 2008 and 2013 errata editions of the NEHRP Recommended Provisions for Seismic Regulations for New Buildings and Other Structures in conjunction with user -inputted Site location to calculate seismic design parameters and response spectra (both for period and displacement) for soil profile Site Classifications A through E. Output from the web -based program are included in this Appendix. GIR4501utions, INC. 1/8/2019 U.S. Seismic Design Maps b OSHPD Orcutt Expansion Area Latitude, Longitude: 35.254508,-120.633424 It 19 Graduate Restaurants Inc Hansen I n 0 nMap data©20'19 Google Date 1/8/2019, 9:06:54 AM Design Code Reference Document ASCE7-10 Risk Category II Site Class D - Stiff Soil Type Value Description SS 1.154 MCER ground motion. (for 0.2 second period) S, 0.441 MCER ground motion. (for 1.0s period) SMs 1.198 Site -modified spectral acceleration value SMt 0.688 Site -modified spectral acceleration value SDS 0.799 Numeric seismic design value at 0.2 second SA SDI 0.459 Numeric seismic design value at 1.0 second SA Type Value Description SDC D Seismic design category Fa 1.039 Site amplification factor at 0.2 second Fv 1.559 Site amplification factor at 1.0 second PGA 0.466 MCEG peak ground acceleration FPGA 1.034 Site amplification factor at PGA PGAM 0.482 Site modified peak ground acceleration TL 8 Long -period transition period in seconds SsRT 1.154 Probabilistic risk -targeted ground motion. (0.2 second) SsUH 1.23 Factored uniform -hazard (2% probability of exceedance in 50 years) spectral acceleration SsD 2.483 Factored deterministic acceleration value. (0.2 second) S1 RT 0.441 Probabilistic risk -targeted ground motion. (1.0 second) S1 UH 0.456 Factored uniform -hazard (2% probability of exceedance in 50 years) spectral acceleration. S1 D 0.844 Factored deterministic acceleration value. (1.0 second) PGAd 0.891 Factored deterministic acceleration value. (Peak Ground Acceleration) CRS 0.938 Mapped value of the risk coefficient at short periods CR1 0.967 Mapped value of the risk coefficient at a period of 1 s https://seismicmaps.org/ 1/2 1 /8/2019 1.5 1.0 m 0.5 0.0 0.0 MCER Response Spectrum 0.6 0.4 0.0 U.S. Seismic Design Maps 2.5 5.0 7.5 Period, T (sec) Sa(g) Design Response Spectrum 0.0 2.5 5.0 7.5 Period, T (sec) Sa(g) hftps:Hseismicmaps.org/ 2/2 APPE T \_ Preliminary Grading Specifications Key and Bench with Backdrain GeoSUIUU IS, INC. PRELIMINARY GR L)ING SPECIFICATIONS A. General These preliminary specifications have been prepared for the subject site; GeoSolutions, Inc. should be consulted prior to the commencement of site work associated with site development to ensure compliance with these specifications. 2. GeoSolutions, Inc. should be notified at least 72 hours prior to site clearing or grading operations on the property in order to observe the stripping of surface materials and to coordinate the work with the grading contractor in the field. These grading specifications may be modified and/or superseded by recommendations contained in the text of this report and/or subsequent reports. 4. If disputes arise out of the interpretation of these grading specifications, the Soils Engineer shall provide the governing interpretation. B. Obli6ation of Parties The Soils Engineer should provide observation and testing services and should make evaluations to advise the client on geotechnical matters. The Soils Engineer should report the findings and recommendations to the client or the authorized representative. The client should be chiefly responsible for all aspects of the project. The client or authorized representative has the responsibility of reviewing the findings and recommendations of the Soils Engineer. During grading the client or the authorized representative should remain on -site or should remain reasonably accessible to all concerned parties in order to make decisions necessary to maintain the flow of the project. The contractor is responsible for the safety of the project and satisfactory completion of all grading and other operations on construction projects, including, but not limited to, earthwork in accordance with project plans, specifications, and controlling agency requirements. C. :Site Preparation The client, prior to any site preparation or grading, should arrange and attend a meeting which includes the grading contractor, the design Structural Engineer, the Soils Engineer, representatives of the local building department, as well as any other concerned parties. All parties should be given at least 72 hours notice. 2, All surface and sub -surface deleterious materials should be removed from the proposed building and pavement areas and disposed of off -site or as approved by the Soils Engineer. This includes, but is not limited to, any debris, organic materials, construction spoils, buried utility line, septic systems, building materials, and any other surface and subsurface structures within the proposed building areas. Trees designated for removal on the construction plans should be removed and their primary root systems grubbed under the observations of a representative of GeoSolutions, Inc. Voids left from site clearing should be cleaned and backfilled as recommended for structural fill. C[Ln5ol�tinJr�9, INC. Once the Site has been cleared, the exposed ground surface should be stripped to remove surface vegetation and organic soil. A representative of GeoSolutions, Inc. should determine the required depth of stripping at the time of work being completed. Strippings may either be disposed of off - site or stockpiled for future use in landscape areas, if approved by the landscape architect. D. Site Protectioir Protection of the Site during the period of grading and construction should be the responsibility of the contractor. ?. The contractor should be responsible for the stability of all temporary excavations. During periods of rainfall, plastic sheeting should be kept reasonably accessible to prevent unprotected slopes from becoming saturated. Where necessary during periods of rainfall, the contractor should install check -dams, de -silting basins, sand bags, or other devices or methods necessary to control erosion and provide safe conditions. E. Excavations 1. Materials that are unsuitable should be excavated under the observation and recommendations of the Soils Engineer. Unsuitable materials include, but may not be limited to: 1) dry, loose, soft, wet, organic, or compressible natural soils; 2) fractured, weathered, or soft bedrock; 3) non -engineered fill; 4) other deleterious materials; and 5) materials identified by the Soils Engineer or Engineering Geologist. ?. Unless otherwise recommended by the Soils Engineer and approved by the local building official, permanent cut slopes should not be steeper than 2:1 (horizontal to vertical). Final slope configurations should conform to section 1804 of the 2016 California Building Code unless specifically modified by the Soil Engineer/Engineering Geologist. �. The Soil Engineer/Engineer Geologist should review cut slopes during excavations. The contractor should notify the Soils Engineer/Engineer Geologist prior to beginning slope excavations. F. Structural Fill Structural fill should not contain rocks larger than 3 inches in greatest dimension, and should have no more than 15 percent larger than 2.5 inches in greatest dimension. Imported fill should be free of organic and other deleterious material and should have very low expansion potential, with a plasticity index of 12 or less. Before delivery to the Site, a sample of the proposed import should be tested in our laboratory to determine its suitability for use as structural fill. G. Conipactvrd Fill Structural fill using approved import or native should be placed in horizontal layers, each approximately 8 inches in thickness before compaction. On -site inorganic soil or approved imported fill should be conditioned with water to produce a soil water content near optimum moisture and compacted to a minimum relative density of 90 percent based on ASTM D1557-07. Geo5olutfons, nc. �.. Fill slopes should not be constructed at gradients greater than 2-to-1 (horizontal to vertical). The contractor should notify the Soils Engineer/Engineer Geologist prior to beginning slope excavations. If fill areas are constructed on slopes greater than 10-to-I (horizontal to vertical), we recommend that benches be cut every 4 feet as fill is placed. Each bench shall be a minimum of 10 feet wide with a minimum of 2 percent gradient into the slope. If fill areas are constructed on slopes greater than 5-to-1, we recommend that the toe of all areas to receive fill be keyed a minimum of 24 inches into underlying dense material. Key depths are to be observed and approved by a representative of GeoSolutions, Inc. Sub -drains shall be placed in the keyway and benches as required. H, Drainaue During grading, a representative of GeoSolutions, Inc. should evaluate the need for a sub -drain or back -drain system. Areas of observed seepage should be provided with sub -surface drains to release the hydrostatic pressures. Sub -surface drainage facilities may include gravel blankets, rock filled trenches or Multi -Flow systems or equal. The drain system should discharge in a non -erosive manner into an approved drainage area. 2. All final grades should be provided with a positive drainage gradient away from foundations. Final grades should provide for rapid removal of surface water runoff. Ponding of water should not be allowed on building pads or adjacent to foundations. Final grading should be the responsibility of the contractor, general Civil Engineer, or architect. Concentrated surface water runoff within or immediately adjacent to the Site should be conveyed in pipes or in lined channels to discharge areas that are relatively level or that are adequately protected against erosion. Water from roof downspouts should be conveyed in solid pipes that discharge in controlled drainage localities. Surface drainage gradients should be planned to prevent ponding and promote drainage of surface water away from building foundations, edges of pavements and sidewalks. For soil areas we recommend that a minimum of 2 percent gradient be maintained. Attention should be paid by the contractor to erosion protection of soil surfaces adjacent to the edges of roads, curbs and sidewalks, and in other areas where hard edges of structures may cause concentrated flow of surface water runoff. Erosion resistant matting such as Miramat, or other similar products, may be considered for lining drainage channels. Sub -drains should be placed in established drainage courses and potential seepage areas. The location of sub -drains should be determined after a review of the grading plan. The sub -drain outlets should extend into suitable facilities or connect to the proposed storm drain system or existing drainage control facilities. The outlet pipe should consist of a non -perforated pipe the same diameter as the perforated pipe. ff�§EdIUU , INC. Maintenance Maintenance of slopes is important to their long-term performance. Precautions that can be taken include planting with appropriate drought -resistant vegetation as recommended by a landscape architect, and not over -irrigating, a primary source of surficial failures. 2, Property owners should be made aware that over -watering of slopes is detrimental to long term stability of slopes. J. Underground Facilities Construction The attention of contractors, particularly the underground contractors, should be drawn to the State of California Construction Safety Orders for "Excavations, Trenches, Earthwork." Trenches or excavations greater than 5 feet in depth should be shored or sloped back in accordance with OSHA Regulations prior to entry. Bedding is defined as material placed in a trench up to 1 foot above a utility pipe and backfill is all material placed in the trench above the bedding. Unless concrete bedding is required around utility pipes, free -draining sand should be used as bedding. Sand to be used as bedding should be tested in our laboratory to verify its suitability and to measure its compaction characteristics. Sand bedding should be compacted by mechanical means to achieve at least 90 percent relative density based on ASTM D1557-07. On -site inorganic soils, or approved import, may be used as utility trench backfill. Proper compaction of trench backfill will be necessary under and adjacent to structural fill, building foundations, concrete slabs, and vehicle pavements. In these areas, backfill should be conditioned with water (or allowed to dry), to produce a soil water content of about 2 to 3 percent above the optimum value and placed in horizontal layers, each not exceeding 8 inches in thickness before compaction. Each layer should be compacted to at least 90 percent relative density based on ASTM D1557-07. The top lift of trench backfill under vehicle pavements should be compacted to the requirements given in report under Preparation of Paved Areas for vehicle pavement sub - grades. Trench walls must be kept moist prior to and during backfill placement. K. Completion of `York After the completion of work, a report should be prepared by the Soils Engineer retained to provide such services. The report should including locations and elevations of field density tests, summaries of field and laboratory tests, other substantiating data, and comments on any changes made during grading and their effect on the recommendations made in the approved Soils Engineering Report. 2. Soils Engineers shall submit a statement that, to the best of their knowledge, the work within their area of responsibilities is in accordance with the approved soils engineering report and applicable provisions within Chapter 18 of the 2016 CBC. Uwn5oluthn , iNc.