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Home My WebLink AboutCT 2017-0005; GRAND WEST; GEOTECHNICAL INVESTIGATION; 2017-05-31----------- -----.. --... ----------... ------ Construction Testing & Engineering, Inc. Inspection I Testing I Geotechnical I Environmental & Construction Engineering I Civil Engineering I Surveying GEOTECHNICAL INVESTIGATION PROPOSED TWO TRIPLEX TOWNHOME CONDOMINIUMS 972 AND 988 GRAND A VENUE CARLSBAD, CALIFORNIA Prepared for: MR. ERIC DEJONG C/O: CONSULTANTS COLLABORATIVE MS. TERRY MATHEW 160 INDUSTRIAL STREET SAN MARCOS, CALIFORNIA 92078 Prepared by: CONSTRUCTION TESTING & ENGINEERING, INC. 1441 MONTIEL ROAD, SUITE 115 ESCONDIDO, CALIFORNIA 92026 R--=,.,. -~~ ''7'r:--i. I,' ·-J AUG O /; 2011 CITYC' . , PL .. I l,, i i\LSGAD ANNING DIVIS/ON CTE JOB NO.: 10-136430 May 31, 2017 1441 Montiel Road, Suite 115 I Escondido, CA92026 I Ph (760) 746-4955 I Fax (760) 746-9806 I www.cte-inc.net TABLE OF CONTENTS 1.0 INTRODUCTION AND SCOPE OF SERVICES ................................................................... I 1.1 Introduction ................................................................................................................... I 1.2 Scope of Services .......................................................................................................... I 2.0 SITE DESCRIPTION ............................................................................................................... 2 3.0 FIELD INVESTIGATION AND LABORATORY TESTING ................................................ 2 3. I Field Investigation ........................................................................................................ 2 3.2 Laboratory Testing ........................................................................................................ 2 3 .3 Percolation Testing ....................................................................................................... 3 3 .3 .1 Calculated Infiltration Rates .......................................................................... 4 3 .3 .2 Calculated Infiltration Rates .......................................................................... 6 4.0 GEOLOGY ............................................................................................................................... 7 4. I General Setting ............................................................................................................. 7 4.2 Geologic Conditions ..................................................................................................... 7 4.2.1 Residual Soil .................................................................................................. 7 4.2.2 Quaternary Old Paralic Deposits (Qop) ......................................................... 8 4.3 Groundwater Conditions ............................................................................................... 8 4.4 Geologic Hazards .......................................................................................................... 8 4.4.1 Surface Fault Rupture .................................................................................... 9 4.4.2 Local and Regional Faulting .......................................................................... 9 4.4.3 Liquefaction and Seismic Settlement Evaluation ........................................ I 0 4.4.4 Tsunamis and Seiche Evaluation ................................................................. I 0 4.4.5 Landsliding .................................................................................................. 11 4.4.6 Compressible and Expansive Soils .............................................................. 11 4.4.7 Corrosive Soils ............................................................................................. 12 5.0 CONCLUSIONS AND RECOMMENDATIONS ................................................................. 13 5.1 General ........................................................................................................................ 13 5.2 Site Preparation ........................................................................................................... 13 5 .3 Site Excavation ........................................................................................................... 14 5.4 Fill Placement and Compaction .................................................................................. 14 5.5 Fill Materials ............................................................................................................... 15 5.6 Temporary Construction Slopes ................................................................................. 16 5.7 Foundations and Slab Recommendations ................................................................... 17 5.7.1 Foundations .................................................................................................. 17 5. 7 .2 Foundation Settlement ................................................................................. 18 5.7.3 Foundation Setback ...................................................................................... 18 5.7.4 Interior Concrete Slabs ................................................................................ 19 5 .8 Seismic Design Criteria .............................................................................................. 20 5. 9 Lateral Resistance and Earth Pressures ...................................................................... 21 5.10 Exterior Flatwork ...................................................................................................... 23 5. I I Pavements ................................................................................................................. 23 5 .12 Drainage .................................................................................................................... 24 5.13 Slopes ........................................................................................................................ 25 5 .14 Plan Review .............................................................................................................. 26 5 .15 Construction Observation ......................................................................................... 26 6.0 LI MITA TIO NS OF INVESTIGATION ................................................................................. 27 FIGURES FIGURE I FIGURE 2 FIGURE 3 FIGURE 4 APPENDICES APPENDIX A APPENDIX B APPENDIX C APPENDIX D APPENDIX E TABLE OF CONTENTS SITE LOCATION MAP GEOLOGIC/ EXPLORA T!ON LOCATION MAP REGIONAL FAULT AND SEISMICITY MAP CONCEPTUAL RETAINING WALL DRAINAGE REFERENCES FIELD EXPLORATION METHODS LOGS LABORATORY METHODS AND RES UL TS STANDARD GRADING SPECIFICATIONS C.4-1 WORKSHEET Geotechnical Investigation Proposed Two Triplex Townhomes Page I 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 CTE Job No.: 10-136430 1.0 INTRODUCTION AND SCOPE OF SERVICES I. I Introduction This report presents the results of the geotechnical investigation, performed by Construction Testing and Engineering, Inc. (CTE), and provides preliminary conclusions and recommendations for the proposed improvements at the subject site located in Carlsbad, California. This investigation was performed in general accordance with the terms ofCTE proposal G-4029A, dated March 27, 2017. CTE understands that the proposed site improvements are to consist of two structures of two-to three-story construction, paved parking and flatwork, retention basins, associated utilities, landscaping, and ancillary improvements. Preliminary recommendations for excavations, fill placement, and foundation design for the proposed improvements are presented in this report. Reviewed references are provided in Appendix A. 1.2 Scope of Services The scope of services provided included: • Review of readily available geologic and geotechnical reports. • Excavation of exploratory borings utilizing limited-access manually operated drilling equipment. • Percolation testing in accordance with County of San Diego Department of Environmental Health (DEH) procedures. • Laboratory testing of selected soil samples. • Description of site geology and evaluation of potential geologic hazards. • Engineering and geologic analysis. • Preparation of this geotcchnical investigation report. \\Esc __ scrvcr\pro_jects\ 1 0-1 3643Ci\Rpt __ Gcotcchn 1cal doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 Page 2 CTE Job No.: 10-136430 2.0 SITE DESCRIPTION The project site is located at 972 and 988 Grand Avenue in Carlsbad, California (Figure 1 ). The site is bounded by Grand Avenue to the southeast and residences on all other sides. The project area is generally flat at an approximate elevation of68 feet msl (above mean sea level). 3.0 FIELD INVESTIGATION AND LABORATORY TESTING 3 .1 Field Investigation CTE performed the field investigation on May 9, 2017. The field work consisted of a site reconnaissance and excavation of four exploratory borings and four percolation test holes. The borings were excavated with a manually operated three-inch diameter auger. Bulk samples were collected from the cuttings. The soils were logged in the field by a CTE Engineering Geologist, and were classified in general accordance with the Unified Soil Classification System via visual and tactile methods. The field descriptions have been modified, where appropriate, to reflect laboratory test results. Boring logs, including descriptions of the soils encountered. are included in Appendix B. The approximate locations of the borings are presented on Figure 2. 3.2 Laboratory Testing Laboratory tests were conducted on selected soil samples for classification purposes, and to evaluate physical properties and engineering characteristics. Laboratory tests included: Gradation, Expansion Index (El), and Chemical Characteristics. Test descriptions and laboratory test results for the selected soils are included in Appendix C. \\be_ scrver\pro.1ccts\ I 0-1364 3G\Rpt_ Geotechmcal.doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 3.3 Percolation Testing Page 3 CTE Job No.: 10-136430 The percolation testing was performed in accordance with SD DEH Case III method, which is performed when presoak water infiltrates through the hole overnight. The presoak duration for all tests ranged from approximately 23 to 24 hours, which is within the SD DEH 15 to 30 hour presoak range. Percolation test results and rates are presented below in Table 3.3. The C.4-1 infiltration feasibility worksheet is also included in Appendix E. ~ .· 1'ABl,E $.;i .·. . . • PE~COLA no!ftV,'f'Es .. Boring/Depth Time Time Initial Water Final Water Water Level Percolation Rate (inches) Change Level Level Change (minutes) (inches) (inches) (inches) Inches/ Inches P-1/51.0 Hour I Minut Soil: e Qop 0930 Initial 43.0 NIA NIA 1000 30 43.0 44.1875 1.19 Case III 1030 60 43.0 43.875 0.88 1100 90 43.875 44.75 0.88 1130 120 43.0 44.25 1.25 1200 150 43.0 43.75 0.75 1230 180 43.75 44.375 0.63 1300 210 43.0 43.75 0.75 1330 240 43.0 43.75 0.75 1.5 0.025 Boring/Depth Time Time Water Level Final Water Water Level Percolation Rate (inches) Change (inches) Level Change (minutes) (inches) (inches) Inches/ Inches P-2149.0 Hour I Minut Soil: e Qop 0932 Initial 41.0 NIA NIA 1002 30 41.0 42.5 1.50 Case III 1032 60 41.0 42.4 1.40 1102 90 41.0 42.4375 1.44 1132 120 41.0 42.1875 1.19 1202 150 41.0 41. 75 0.75 1232 180 41. 75 42.31 0.56 1302 210 41.0 41.60 0.60 \\Esc __ scrvcr\pro_1ects\ I 0-l 364 3(i\Rpt_ Geotechnica\.doc Geotechnical Investigation Proposed Two Triplex Townhomes Page 4 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 CTEJobNo.: I0-13643G 1332 240 41.60 42.2875 0.69 1.38 0.023 Boring/Depth Time Time Water Level Final Water Water Level Percolation Rate (inches) Change (inches) Level Change (minutes) (inches) (inches) Inches/ Inches P-3/51.0 Hour I Minut Soil: e Qop 0934 Initial 39.0 NIA NIA 1004 30 39.0 40.9375 1.94 Case Ill 1034 60 39.0 40.625 1.63 1104 90 39.0 40.5 1.50 1134 120 39.0 40.5 1.50 1204 150 39.0 40.375 1.38 1234 180 39.0 40.375 1.38 1304 210 39.0 40.1875 1.19 1334 240 39.0 40.25 1.25 2.5 0.042 Boring/Depth Time Time Water Level Final Water Water Level Percolation Rate (inches) P-4/50.0 Soil: Qop Case Ill NOTES Change (inches) Level Change (minutes) (inches) (inches) 0936 Initial 42.0 NIA NIA 1006 30 42.0 42.25 0.25 1036 60 42.25 42.50 0.25 1106 90 42.50 42.75 0.25 1136 120 42.75 43.00 0.25 1206 150 42.0 42.0625 0.0625 1236 180 42.625 42.125 0.0625 1306 210 42.125 42.1875 0.0625 1336 240 42.1875 42.25 0.0625 Qop ~ Quaternary Old Paralic Deposits. Water level was measured from a fixed point at the top of the hole. The test holes had a diameter six inches. Weather was overcast and mild during the percolation testing. 3.3.1 Calculated Infiltration Rates Inches/ Inches Hour I Minut e 0.125 0.0021 As per the County of San Diego BMP design documents (February 2016) infiltration rates arc to be evaluated through the Porche\ Method. CTE utilized the Porche! Method through \ \l:sc _ servcr\projcctsl I 0-13643( i\Rpt_ (ieotechnical .doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 Page 5 CTE Job No.: 10-13643G guidance of the County of Riverside (2011 ). The intent of the infiltration rate is to take into account bias inherent in percolation test bore hole sidewall infiltration, which would not occur at a constructed basin bottom where such sidewalls are not present. The infiltration rate (It) is derived by the equation: It= {(change H 60 r) / [change t(r+2Hav)]) Where: Change t=time interval Df=final depth to water r=test hole radius change t=60 minutes Do=initial depth to water Dt=total depth of test hole Ho=Dt -Do is initial height of water at selected time interval Hf=Dt-Df-is the final height of water at the selected time interval Change H=is the change in height over the time interval Hav=(Ho+Hf) / 2 is the average head height over the time interval Given the measurement values of Table 1.0, the calculated infiltration rates without a Factor of Safety applied are as follows. P-1 (units in inches) Dt'=43.75 Do=43.0 Dt=51.0 r=3 change t=30 minutes Calculated Infiltration Rate=0.2466 inches/hour P-2 (units in inches) Df=42.2875 D0=41.60 Dt=49.0 r=3 change t=30 minutes Calculated Infiltration Rate=0.2411 inches/hour \ \1-.sc __ scrver\pro_1ccts\ l 0-1364 3G\Rpt __ Gcotechnical. doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 P-3 (units in inches) Df=40.25 Do=39.0 Dt=S 1.0 r=3 change t=30 minutes Calculated Infiltration Rate=0.29 I 3 inches/hour P-4 (units in inches) Df=42.2875 D0=41.60 Dt=49.0 r=3 change t=30 minutes Calculated Infiltration Rate=0.020 inches/hour 3.3.2 Calculated Infiltration Rates Page 6 CTEJobNo.: 10-136430 Infiltration rates have been calculated utilizing the factor of safety (FOS) of2 in the following Table 1.1. The project stormwater or basin designer may modify the factor of safety based on their independent evaluation. The infiltration feasibility information is also presented on the attached C .4-1 Worksheet. TABLE3.3.2 RESULTS OF PERCOLATION TESTING WITH FACTOR OF SAFETY APPLIED Test Location Percolation Rate Infiltration Rate Infiltration Rate with FOS of /inches/minute) (inches ner hour) 2 Ann lied (inches per hour) P-1 0.025 0.25 0.12 P-2 0.023 0.24 0.12 P-3 0.042 0.29 0.15 P-4 0.0021 0.020 0.010 I \F sc _.~crvcr\projects\ I O-136430\Rpt_ ( icotcchnical .doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 Page 7 CTE Job No.: 10-13643G Based on the calculated rates and other site factors, portions of the site meet minimum County requirements for partial infiltration. An area that could be considered for partial Infiltration design options is presented on Figure 2. 4.0GEOLOGY 4.1 General Setting Carlsbad is located within the Peninsular Ranges physiographic province that is characterized by northwest-trending mountain ranges, intervening valleys, and predominantly northwest trending regional faults. The greater San Diego Region can be further subdivided into the coastal plain area, a central mountain-valley area and the eastern mountain valley area. The project site is located within the coastal plain area that is characterized by Cretaceous, Tertiary, and Quaternary sedimentary deposits that onlap an eroded basement surface consisting of Jurassic and Cretaceous crystalline rocks. 4.2 Geologic Conditions Based on the regional geologic map prepared by Kennedy and Tan (2007), the near surface geologic unit underlying the site consists of Quaternary Old Paralic Deposits. Unit 6-7. However, based on the site explorations, Residual Soil was observed overlying the Quaternary Old Paralic Deposits. Descriptions of the geologic and soil units encountered are presented below. 4.2.1 Residual Soil Where observed, the Residual Soil generally consists ofloose to medium dense, dark reddish brown, silty to clayey fine grained sand. This unit is relatively thin and blankets the \\Esc _ scrvcr\projccts\ I 0-13643(]\Rpt Gcotcchnical.doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 Page 8 CTE Job No.: l0-13643G underlying Old Paralic Deposits, and is not considered suitable for support of proposed structural improvements or compacted fill without first processing as indicated herein. 4.2.2 Quaternary Old Paralic Deposits (Qop) Quaternary Old Paralic Deposits were found to be the underlying geologic unit at the site. Where observed, these materials generally consist of medium dense to dense, reddish brown silty to clayey fine grained sandstone. These materials are considered suitable for support of proposed improvements and compacted fill as indicated herein. 4.3 Groundwater Conditions During the recent investigation, likely perched subsurface water was encountered at a depth of approximately 11 feet below existing grades. Based on site conditions and recent findings, the potential for relatively shallow subsurface water exists at the site, which could seasonally impact deeper site excavations and earthwork during project construction. This groundwater may also impact the retention basin feasibility. However, a permanent shallow static groundwater table is not generally anticipated to be present at the subject site. Proper site drainage is to be designed, installed, and maintained as per the recommendations of the project civil engineer of record. 4.4 Geologic Hazards Geologic hazards that were considered to have potential impacts to site development were evaluated based on field observations, literature review, and laboratory test results. It appears that the geologic hazards at the site are primarily limited to those caused by shaking from earthquake-generated \\Fsc _ servcr\prnjccts\ I 0-1 3643( i\Rpt_ ( ieotechnical.doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 Page 9 CTEJobNo.: 10-136430 ground motions. The following paragraphs discuss the geologic hazards considered and their potential risk to the site. 4.4.1 Surface Fault Rupture Based on the site reconnaissance and review of referenced literature, the site is not within a State of California-designated Alquist-Priolo Earthquake Fault Studies Zone or Local Special Studies Zone and no known active fault traces underlie, or project toward, the site. According to the California Division of Mines and Geology, a fault is active ifit displays evidence of activity in the last 11,000 years (Hart and Bryant, revised 2007). Therefore, the potential for surface rupture from displacement or fault movement beneath the proposed improvements is considered to be low. 4.4.2 Local and Regional Faulting The California Geological Survey (CGS) and the United States Geological Survey (USGS) broadly group faults as "Class A" or "Class B" (Cao, 2003; Frankel et aL 2002). Class A faults are generally identified based upon relatively well-defined paleoseismic activity, and a fault-slip rate of more than 5 millimeters per year (nun/yr). In contrast, Class B faults have comparatively less defined paleoseismic activity and are considered to have a fault-slip rate less than 5 mm/yr. The nearest known Class B fault is the Newport-Inglewood Fault, which is approximately 8.5 kilometers west of the site (Blake, T.F., 2000). The nearest known Class A fault is the Temecula segment of the Elsinore Fault, which is located approximately 38.6 kilometers east of the site. \ \]-:sc _ server\pro_1ccts\ I O-136430\Rpt_ Geotechnical doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 Page IO CTEJobNo.: 10-136430 The site could be subjected to significant shaking in the event of a major earthquake on any of the faults noted above or other faults in the southern California or northern Baja California area. 4.4.3 Liquefaction and Seismic Settlement Evaluation Liquefaction occurs when saturated fine-grained sands or silts lose their physical strengths during earthquake-induced shaking and behave like a liquid. This is due to loss of point-to-point grain contact and transfer of normal stress to the pore water. Liquefaction potential varies with water level, soil type, material gradation, relative density, and probable intensity and duration of ground shaking. Seismic settlement can occur with or without liquefaction; it results from densification of loose soils. The site is underlain at shallow depths by medium dense to dense Quaternary Old Paralic Deposits. In addition, loose surficial soils within proposed improvement areas arc to be overexcavated and compacted as engineered till as recommended herein. Therefore, the potential for liquefaction or significant seismic settlement at the site is considered to be low. 4.4.4 Tsunamis and Seiche Evaluation According to State of California Emergency Management Agency mapping, the site is not located within a tsunami inundation zone based on distance from the coastline and elevation \\1-:sc_ sem:r\pro_1ccts\l O-I 3643(i\Rpt Gcotcchnical doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 Page 11 CTE Job No.: 10-136430 above sea level. Damage resulting from oscillatory waves (seiches) is considered unlikely due to the absence of nearby confined bodies of water. 4.4.5 Landsliding According to mapping by Tan ( 1995), the site is considered only "Marginally Susceptible" to landsliding and no landslides are mapped in the site area. Furthermore, landslides or similar associated features were not observed during the recent field exploration. Therefore, landsliding is not considered to be a significant geologic hazard at the site. 4.4.6 Compressible and Expansive Soils The Residual Soil across the surface of the site is considered to be potentially compressible. Therefore, these soils should be overexcavated, processed, and placed as a properly compacted fill as recommended herein. Based on the field data, site observations, and laboratory results, the underlying Old Paralic Deposits are not considered to be subject to significant compressibility under the anticipated loads. Based on observation and laboratory test results, soils at the site arc generally anticipated to exhibit Very Low expansion potential (Expansion Index of20 or less). Therefore, expansive soils are not anticipated to present significant adverse impacts to site development. Additional evaluation of near-surface soils can and should be performed based on field observations during grading activities. \\Esc _ servcr\prujccts\ IO-I 3643(i\Rpt_ Gcotcchnical.doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 4.4. 7 Corrosive Soils Page 12 CTE Job No.: I 0-13643G Chemical testing was performed to evaluate the potential effects that site soils may have on concrete foundations and various types of buried metallic utilities. Soil environments detrimental to concrete generally have elevated levels of soluble sulfates and/or pH levels less than 5.5. According to American Concrete Institute (AC!) Table 318 4.3.1, specific guidelines have been provided for concrete where concentrations of soluble sulfate (SO4) in soil exceed 0.1 percent by weight. These guidelines include low water: cement ratios, increased compressive strength, and specific cement type requirements. Based on the results of the Sulfate and pH testing performed, onsite soils are anticipated to generally have a negligible corrosion potential to Portland cement concrete improvements. A minimum resistivity value less than approximately 5,000 ohm-cm, and/or soluble chloride levels in excess of 200 ppm generally indicate a corrosive environment to buried metallic utilities and untreated conduits. Based on the obtained resistivity value of 15,700 ohm-cm and soluble chloride level of 13.4 ppm, onsite soils are anticipated to have a low corrosion potential for buried uncoated/unprotected metallic conduits. Nevertheless, at a minimum, the use of buried plastic piping or conduits could be beneficial, where feasible. \\Esc _.~crvcr\projects\ I 0-1 3643(j\Rpt _ ( ieotech111cal .doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 Page 13 CTE Job No.: 10-13643G The results of the chemical tests performed are presented in the attached Appendix C. However, CTE does not practice corrosion engineering. Therefore, a corrosion engineer or other qualified consultant could be contacted if site specific corrosivity issues are of concern. 5.0 CONCLUSIONS AND RECOMMENDATIONS 5.1 General CTE concludes that the proposed improvements at the site are feasible from a geotechnical standpoint, provided the recommendations in this report are incorporated into the design and construction of the project. Recommendations for the proposed earthwork and improvements are included in the following sections and Appendix D. However, recommendations in the text of this report supersede those presented in Appendix D should variations exist. These recommendations should either be confirmed as appropriate and/or updated during or following rough grading at the site. 5.2 Site Preparation Prior to grading, the site should be cleared of any existing building materials or improvements that are not to remain. Objectionable materials, such as construction debris and vegetation, not suitable for structural backfill should be properly disposed of offsite. In the area of the proposed structures (and a minimum five feet laterally beyond, where feasible), existing soils should be uniformly excavated to a minimum depth of 18 inches below the bottom of the deepest proposed foundations, or to the depth of suitable material, whichever depth is greatest. Localized areas of loose and \\Esc _ scrvcr\projects\ I 0-1364](1\Rpt_ Geotechn1cal.<loc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad. California May 31, 2017 Page 14 CTEJobNo.: 10-13643G potentially compressible material could require overexcavation to deeper elevations, based on conditions encountered during grading. Overexcavations should extend at least five feet laterally beyond the limits of the proposed building, where feasible. Excavations in proposed pavement, flatwork. or other minor improvement areas should be conducted to a minimum depth of two feet below proposed or existing grades. or to suitable underlying materials, whichever depth is shallowest. A CTE geotechnical representative should observe the exposed ground surface at the overexcavation bottoms to evaluate the exposed conditions. The exposed subgrades to receive fill should be proof~ rolled or scarified a minimum of nine inches, moisture conditioned to a minimum of two percent above optimum, and properly compacted prior to additional fill placement. 5.3 Site Excavation Generally, excavation of site materials may be accomplished with heavy-duty construction equipment under normal conditions. However, the Old Paralic Deposits may become increasingly difficult to excavate with depth. Materials also appear to be. at least locally, very granular and could be very sensitive to caving and/or erosion. 5.4 Fill Placement and Compaction Granular fill and backfill should be compacted to a minimum relative compaction of90 percent at a moisture content of at least two percent above optimum, as evaluated by ASTM D 1557. The \\Esc _scrver\pro_jecls\l0-13643(i\Rpt (icotcchnical doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May31,2017 Page 15 CTE Job No.: 10-136430 optimum lift thickness for fill soil will depend on the type of compaction equipment used. Generally, backfill should be placed in uniform, horizontal lifts not exceeding eight inches in loose thickness. Fill placement and compaction should be conducted in conformance with local ordinances. 5.5 Fill Materials Properly moisture-conditioned very low expansion potential soils derived from the on-site excavations are considered suitable for reuse on the site as compacted fill. If used. these materials should be screened of organics and materials generally greater than three inches in maximum dimension. Irreducible materials greater than three inches in maximum dimension should generally not be used in shallow fills (within three feet of proposed grades). In utility trenches, adequate bedding should surround pipes. Imported fill beneath structures, flatwork, and pavements should have an Expansion Index of 30 or less (ASTM D 4829). Imported fill soils for use in structural or slope areas should be evaluated by the geotechnical engineer before being imported to the site. Minor retaining wall backfill (if necessary) located within a 45-degree wedge extending up from the heel of the wall should consist of soil having an Expansion Index of20 or less (ASTM D 4829) with less than 30 percent passing the No. 200 sieve. The upper 12 to I 8 inches of wall backfill could consist of lower permeability soils, in order to reduce surface water infiltration behind walls. The project structural engineer and/or architect should detail proper wall backdrains, including gravel \ 11-:sc _ servcr\projects\ I 0-13643(.i\Rpt_ Geotechnical doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 Page 16 CTE Job No.: I0-13643G drain zones, fills, filter fabric, and perforated drain pipes. However, a conceptual wall backdrain detail, which may be suitable for use at the site, is provided as Figure 4. 5.6 Temporary Construction Slopes The following recommended slopes should be relatively stable against deep-seated failure, but may experience localized sloughing. On-site soils are considered Type B and Type C soils with recommended slope ratios as set forth in Table 5.6. However, due to the at least locally granular and erodible nature of the onsite soils, maximum 1.5:1 temporary slopes are anticipated to be more reliable, and vertical excavations may not remain standing, even at shallow or minor heights. TABLE5.6 RECOMMENDED TEMPORARY SLOPE RA nos SOIL TYPE SLOPE RATIO MAXIMUM HEIGHT (Horizontal: vertical) B (Old Paralic Deposits) I: I (OR FLATTER) IO Feet C (Residual Soil) 1.51 (OR FLATTER) IO Feet Actual field conditions and soil type designations must be verified by a "competent person" while excavations exist, according to Cal-OSHA regulations. In addition, the above sloping recommendations do not allow for surcharge loading at the top of slopes by vehicular traffic, equipment or materials. Appropriate surcharge setbacks must be maintained from the top of all unshared slopes. \\F~c _scrver\pro_jccts\ I 0-1 364Ki\Rpt_ ( icotechnical.doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May31,2017 5.7 Foundations and Slab Recommendations Page 17 CTE Job No.: 10-136430 The following recommendations are for preliminary design purposes only. These recommendations should be reviewed after completion of earthwork to document that conditions exposed are as anticipated, and that the recommended structure design parameters are appropriate. 5.7.1 Foundations Following the preparatory grading recommended herein, continuous and isolated spread footings are anticipated to be suitable for use at this site. It is anticipated that building footings will be founded entirely in properly compacted fill with very low expansion potential. Foundation dimensions and reinforcement should be based on an allowable bearing value of 2.500 pounds per square foot for footings founded entirely upon properly placed compacted fill materials embedded a minimum of 18 inches below the lowest adjacent subgrade elevation. If utilized, continuous footings should be at least 18 inches wide; isolated footings should be at least 24 inches in least dimension. The above bearing values may also be increased by one third for short duration loading which includes the effects of wind or seismic forces. \\E~c _ scrvcr\prnjects\ IO-I 3643G\Rpt Gi.:otcchnical.doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May 3 I, 2017 Page 18 CTE Job No.: 10-13643G An uncorrected 150-pci subgrade modulus is considered suitable for elastic design of foundations as embedded and/or detailed herein. Minimum reinforcement for continuous footings should consist of four No. 4 reinforcing bars; two placed near the top and two placed near the bottom or as per the project structural engineer. The structural engineer should design isolated footing reinforcement. Footing excavations should generally be maintained above optimum moisture content until concrete placement. 5.7.2 Foundation Settlement The maximum total settlement is expected to be on the order of one inch and the maximum differential settlement is expected to be on the order of I /2 inch over a distance of approximately 40 feet. Due to the absence ofa shallow static or sustained groundwater table and the generally dense nature of underlying materials, dynamic settlement is not expected to adversely affect the proposed improvements. 5. 7. 3 Foundation Setback Footings for structures should be designed such that the horizontal distance from the face of adjacent slopes to the outer edge of the footing is at least IO feet. In addition, footings should bear beneath a I: 1 plane extended up from the nearest bottom edge of adjacent trenches and/or excavations. Deepening of affected footings may be a suitable means of attaining the prescribed setbacks. \ \Esc ___ scrvcr\projccts\ I 0-1364 3G\Rpt _Geotechnical .doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 5.7.4 Interior Concrete Slabs Page 19 CTE Job No.: 10-136430 Lightly loaded concrete slabs should be a minimum of 4.5 inches in thickness. Minimum slab reinforcement should consist of #3 reinforcing bars placed on maximum 16-inch centers, each way, at above mid-slab height, but with proper concrete cover. Subgrade materials should generally be maintained at above optimum moisture content until slab underlayment and concrete are placed. Slabs subjected to heavier loads may reqmre thicker slab sections and/or increased reinforcement. A 140-pci subgrade modulus is considered suitable for elastic design of minimally embedded improvements such as slabs-on-grade. In moisture-sensitive floor areas, a suitable vapor retarder of at least 15-mil thickness (with all laps or penetrations sealed or taped) overlying a four-inch layer of consolidated crushed aggregate or gravel (with SE of30 or more) should be installed, as per the 2013 CBC/Green Building Code. An optional maximum two-inch layer of similar material may be placed above the vapor retarder to help protect the membrane during steel and concrete placement. This recommended protection is generally considered typical in the industry. If proposed floor areas or coverings are considered especially sensitive to moisture emissions, additional recommendations from a specialty consultant could be obtained. CTE is not an expert at preventing moisture penetration through slabs. A qualified architect or other experienced professional should be contacted if moisture penetration is a more significant concern. \\Fsc_ ~crver\projects\10-1 3643G\Rpt_ Geotechn1cal.doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 5.8 Seismic Design Criteria Page 20 CTE Job No.: 10-13643G The seismic ground motion values listed in the table below were derived in accordance with the ASCE 7-10 Standard and 2016 CBC. This was accomplished by establishing the Site Class based on the soil properties at the site, and then calculating the site coefficients and parameters using the United States Geological Survey Seismic Design Maps application using the site coordinates of 33.1639 degrees latitude and -117.3448 degrees longitude. These values are intended for the design of structures to resist the effects of earthquake ground motions. TABLE5.8 SEISMIC GROUND MOTION VALUES PARAMETER VALUE CBC REFERENCE (2013) Site Class D ASC E 7, Chapter 20 Mapped Spectral Response Acceleration Parameter, Ss 1.145 Figure 1613.3.1 (I) Mapped Spectral Response Acceleration Parameter, S1 0.439 Figure 1613.3.1 (2) Seismic Coefficient. Fa 1.042 Table 1613.3.3 (!) Seismic Coefficient, F~ 1.561 Table 1613.3.3(2) MCE Spectral Response Acceleration Parameter, SMs 1.193 Section 1613.3.3 MCE Spectral Response 0.685 Section 1613.3.3 Acceleration Parameter, SM1 Design Spectral Response Acceleration, Parameter Sos 0.795 Section 1613.3.4 Design Spectral Response 0.457 Section 1613.3.4 Acceleration, Parameter SDi Peak Ground Acceleration PGAM 0.474 ASCE 7, Section 11.8.3 \\Esc _ si.:n cr\projccts\ I 0-1 3643Ci\Rpt_ Gentechnical .doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 5.9 Lateral Resistance and Earth Pressures Page 21 CTE Job No.: 10-136430 Lateral loads acting against retaining walls may be resisted by friction between the footings and the supporting compacted fill soil and/or Old Paralic Deposits or passive pressure acting against structures. If frictional resistance is used, an allowable coefficient of friction of0.30 (total frictional resistance equals the coefficient of friction multiplied by the dead load) is recommended for concrete cast directly against competent soils. A design passive resistance value of 250 pounds per square foot per foot of depth (with a maximum value of2,000 pounds per square foot) may be used. The allowable lateral resistance can be taken as the sum of the frictional resistance and the passive resistance. provided the passive resistance does not exceed two-thirds of the total allowable resistance. If proposed, retaining walls up to approximately eight feet high and backfilled using granular soils may be designed using the equivalent fluid weights given below. TABLE 5.10 EQUIVALENT FLUID UNIT WEIGHTS (pounds per cubic foot) SLOPE BACKFILL WALL TYPE LEVEL BACKFILL 2: I (HORIZONTAL: VERTICAL) CANTILEVER WALL 30 48 (YIELDING) RESTRAINED WALL 60 75 \\he __ scrvcr\projccts\ I 0-1 3643G\Rpt_ Gcntechnical.doc Geotechnical Investigation Proposed Two Triplex Townhomes Page 22 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 CTE Job No.: 10-13643G Lateral pressures on cantilever retaining walls (yielding walls) due to earthquake motions may be calculated based on work by Seed and Whitman ( 1970). The total lateral thrust against a properly drained and backfilled cantilever retaining wall above the groundwater level can be expressed as: For non-yielding (or "restrained") walls, the total lateral thrust may be similarly calculated based on work by Wood (1973): Where PA= Static Active Thrust (determined using Table 5.9) PK= Static Restrained Wall Thrust (determined using Table 5.9) l'iPA1 = Dynamic Active Thrust Increment= (3/8) kh yH2 l'iPKl: = Dynamic Restrained Thrust Increment = kh yH2 k1, = 2/3 Peak Ground Acceleration = 2/3 (PGAM) H = Total Height of the Wall y = Total Unit Weight of Soil~ 135 pounds per cubic foot The increment of dynamic thrust in both cases should be distributed triangularly with a line of action located at H/3 above the bottom of the wall (SEAOC, 2013). These values assume non-expansive backfill and free-draining conditions. Measures should be taken to prevent moisture buildup behind all retaining walls. Drainage measures should include free- draining backfill materials and sloped, perforated drains. These drains should discharge to an appropriate off-site location. A general or conceptual detail for Retaining Wall Drainage, which may be appropriate for the subject site based on the review of the project structural engineer and/or architect, is attached as Figure 4. Waterproofing should be as specified by the project architect or the waterproofing specialty consultant. \\J:sc_ scrver\pro.1ccts\ IO-l 3643(i\Rpt_ Geokchnical doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 5.10 Exterior Flatwork Page 23 CTE Job No.: 10-136430 To reduce the potential for cracking in exterior non-traffic tlatwork areas caused by mmor movement of subgrade soils and typical concrete shrinkage, it is recommended that such flatwork measure a minimum 4.5 inches thick and be installed with crack-control joints at appropriate spacing as designed by the project architect. Additionally, it is recommended that flatwork be installed with at least No. 3 reinforcing bars on maximum 18-inch centers, each way, at above mid-height of slab but with proper concrete cover, or other reinforcement per the project consultants. Doweling of flatwork joints at critical pathways or similar could also be beneficial in resisting minor sub grade movements. Subgrades should be prepared according to the earthwork recommendations previously given, before placing concrete. Positive drainage should be established and maintained next to all tlatwork. Sub grade materials shall be maintained at, or be elevated to, above optimum moisture content prior to concrete placement. 5.11 Pavements Pavement sections provided are based on estimated Resistance "R"-Value results, traffic indices, and the assumption that the upper foot ofcompacted fill subgrade and overlying aggregate base materials are properly compacted to a minimum 95% relative compaction at a minimum of two percent above optimum moisture content (as per ASTM D 1557). Beneath proposed pavement areas, loose, clayey, or otherwise unsuitable soils are to be removed to the depth of competent underlying material as recommended in Section 5.2. R-Value ofsubgrade material should be verified during grading and pavement sections may be modified as necessary. \ \l'.sc _ server\projccts\ l O" 1364 3( i\Rpt __ (icotcchnical .doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 TABLE 5.12 Page 24 CTEJobNo.: 10-13643G RECOMMENDED AC OR PCC PAVEMENT SECTION 1HICKNESSES Traffic Area Assumed Pre I im inary Asphalt Pavements Portland Cement Traffic Index Subgrade AC Ca!Trans Class II or Concrete "R"-Value Thickness Crushed Miscellaneous Pavements On (INCHES) Aggregate Base Subgrade Thickness (INCHES) (INCHES) Light Auto 4.5 30 3.0 5.0 6.0 Parking & Drive Areas Heavy Quantity 5.5 30 3.0 9.0 7.0 Drive or Impact Areas Asphalt paved areas should be designed, constructed, and maintained in accordance with, for example, the recommendations of the Asphalt Institute, or other widely recognized authority. Concrete paved areas should be designed and constructed in accordance with the recommendations of the American Concrete Institute or other widely recognized authority, particularly with regard to thickened edges, joints, and drainage. The Standard Specifications for Public Works construction ("Greenbook") or Caltrans Standard Specifications may be referenced for pavement materials specifications. 5.12 Drainage Surface runoff should be collected and directed away from improvements by means of appropriate erosion-reducing devices, and positive drainage should be established around proposed improvements. Positive drainage should be directed away from improvements and slope areas at a \ \I ·:sc _scrver\projects\ IO-l 364JG\Rpt _ Gcutcchnical.doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 Page 25 CTE Job No.: I0-13643G minimum gradient of two percent for a distance of at least five feet. However, the project civil engineer should evaluate the on-site drainage and make necessary provisions to keep surface water from affecting the site. Generally, CTE recommends against allowing water to infiltrate building pads or adjacent to slopes and improvements. However, it is understood that some agencies are encouraging the use of storm- water cleansing devices. Therefore, if storm water cleansing devices must be used, it is generally recommended that they be underlain by an impervious barrier and that the infiltrate be collected via subsurface piping and discharged off site. If infiltration must occur, water should infiltrate as far away from structural improvements as feasible. Additionally, any reconstructed slopes descending from infiltration basins should be equipped with subdrains to collect and discharge accumulated subsurface water (Appendix D contains general or typical details for internal fill slope drainage). Infiltration/percolation design and associated information elsewhere in this report should also be reviewed in its entirely. 5.13 Slopes Based on observed conditions and anticipated soil strength characteristics, cut and fill slopes, if proposed at the site, should be constructed at ratios of 2: I (horizontal: vertical) or flatter. These fill slope inclinations should exhibit factors of safety greater than 1.5. Although properly constructed slopes on this site should be grossly stable, the soils will be somewhat erodible. Therefore, runoff water should not be permitted to drain over the edges of \ \Esc _ scrver\projects\ 1 0-1 3M3(i\Rpt_ Gcotcchnical.doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 Page 26 CTE Job No.: I0-13643G slopes unless that water is confined to properly designed and constructed drainage facilities. Erosion-resistant vegetation should be maintained on the face of all slopes. Typically, soils along the top portion ofa fill slope face will creep laterally. CTE recommends against building distress- sensitive hardscape improvements within five feet of slope crests. 5 .14 Plan Review CTE should be authorized to review the project grading and foundation plans pnor to commencement of earthwork to identify potential conflicts with the intent of the geotechnical recommendations. 5.15 Construction Observation The recommendations provided in this report are based on preliminary design information for the proposed construction and the subsurface conditions observed in the explorations performed. The interpolated subsurface conditions should be checked in the field during construction to verify that conditions are as anticipated. Foundation recommendations may be revised upon completion of grading and as-built laboratory test results. Recommendations provided in this report are based on the understanding and assumption that CTE will provide the observation and testing services for the project. All earthwork should be observed and tested to verify that grading activities have been performed according to the recommendations contained within this report. CTE should evaluate all footing trenches before reinforcing steel placement. \\Esc _ scrvcr\projccts\ IO-I 3643G\Rpt_ Gcotcchnical. doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May 31, 2017 Page 27 CTE Job No.: 10-l3643G 6.0 LIMITATIONS OF INVESTlGATION The field evaluation, laboratory testing, and geotechnical analysis presented in this report have been conducted according to current engineering practice and the standard of care exercised by reputable geotechnical consultants performing similar tasks in this area. No other warranty, expressed or implied, is made regarding the conclusions, recommendations and opinions expressed in this report. Variations may exist and conditions not observed or described in this report may be encountered during construction. The recommendations presented herein have been developed in order to help reduce the potential adverse effects of soils movement. However, even with the design and construction precautions provided, some post-construction movement and associated distress should be anticipated. The findings of this report are valid as of the present date. However, changes in the conditions of a property can occur with the passage of time, whether they are due to natural processes or the works of man on this or adjacent properties. In addition, changes in applicable or appropriate standards may occur, whether they result from legislation or the broadening of knowledge. Accordingly, the findings of this report may be invalidated wholly or partially by changes outside our control. Therefore, this report is subject to review and should not be relied upon after a period of three years. CTE's conclusions and recommendations are based on an analysis of the observed conditions. If conditions different from those described in this report arc encountered, this office should be notified and additional recommendations, if required, will be provided. \\E~c,-server\projects\l 0-13643(1\Rpt_ Gcotcchnical doc Geotechnical Investigation Proposed Two Triplex Townhomes 972 and 988 Grand Avenue, Carlsbad, California May31,2017 Page 28 CTE Job No.: 10-136430 The opportunity to be of service on this project is appreciated. Jfyou have any questions regarding this report, please do not hesitate to contact the undersigned. Respectfully submitted, CONSTRUCTION TESTING & ENGINEERING, INC. ~/ Dan T. Math, GE #2665 Principal Engineer j .d; ( Aaron J. Beeby, CEG #2603 Project Geologist AJB/ JFL/DTM :nri Jay F. Lynch, CEG #1890 Principal Engineering Geologist \\Esc _ server\pro_jcct~ \ I 0-1 364 3G\Rpt_ ( ieotcchnical .doc ;eNice Paon R~nt .t Waw Bar ,,.,.,.,.. 't'i , \,. Cl~ Construction Testing & Engineering, Inc. ~c 14-41 Monllel Rd Ste 116, Elc:andldo, CA 92028 Ph (760) 746-4955 SITE INDEX KAP PROPOSED TIO TRIPLEX TOWNBOME CONDOIONIIJKS 972 AND 988 GRAND AVENUE CARLSBAD, CALIFORNIA SCALE: DATE: AS SHOWN 5/17 CTE JOB NO.: FIGURE: 10-136.SG 1 Ol ~ "O N cu ... :::, Ol G: / 0 I') .;t- <O I') ... I 0 / rn +' u .!!I., 0 ... a. / ... cu > ... cu rn I u rn w / / 8-4~ P-4 $ Qop ~ LEGEND Approximate Boring Location Approximate Percolation Test Location Quaternary Old Paralic Deposits Partial Infiltration Area Indicated for BMP Design Options ----:: 30' 0 15' 30' C ~ Construction Testing & Engineering, Inc. ·~c 1441 Montiel Rd S1B 116, Elcondldo, CA 92026 Ph (760) 74&-4965 SCALE DATE: GBOLOGIC/DPLORATION LOCATION IBP 1-~30, 5/17 PROPOSED TIO TRIPLEX TOWN110ME CONDOMINIUMS 972 AND 988 GRAND AVENU1! CTE JOB NO.: FIGURE: CARLSBAD, CALIFORNIA 10-136,3G 2 I I I I I I I I I NOTES: FAULT ACTIVITY MAP OF CALIFORNIA, 2010, CALIFORNIA GEOLOGIC DATA MAP SERIES MAP NO. 6; EPICENTERS OF AND AREAS DAMAGED BY 112 5 CALIFORNIA EARTHQUAKES, 1800-1999 ADAPTED AFl'ER TOPPOZADA, BRANUV, PETERSEN, HALISl'ORM, CRAMER, AND REICHLE, 2000, CDMG MAP SHEET 49 REFERENCE FOR ADDITIONAL EXPLANATION; MODIFIED fflH CISN AND USGS SEISMIC MAPS --·····-?· 12 0 6 12 LEGEND e~iiii-E-s.-~-5. •• 1___.1 1 inch = 12 mi. HISTORIC FAULT DISPLACEMENT (LAST 200 YEARS) HOLOCENE FAULT DISPLACEMENT (DURING PAST 11 ,700 YEARS) LATE QUATERNARY FAULT DISPLACMENT (DURING PAST 700,000 YEARS) QUATERNARY FAULT DISPLACEMENT (AGE UNDIFFERENTIATED) PREQUATERNARY FAULT DISPLACEMENT (OLDER THAN 1.6 MILLION YEARS) 1800- 1868 .::'.. 7.0 0 6.5-6.9 0 5.5-5.9 0 5.0-5.4 0 1869- 1931 1932- 2010 • • • • ~ LAST TWO DIGITS OF M ::_ 6.5 ~ EARTHQUAKE YEAR M E X I ...... .._ C Construction Testing & Engineering, Inc. 1441 Montiel Rd sta 115, Escondido, CA 92026 Ph (760) 748-4955 REGIONAL FAULT AND SEISMICITY MAP """------1 PROPOSED TWO TRIPLEX TOWNHOME CONDOMINIUMS 972 AND 988 GRAND A VENUE CARLSBAD CAIJFORNIA 3 RETAINING WALL FINISH GRADE WALL FOOT ING 12" TO 18" OF LOWER PERMEABILITY NA TJVE MATERIAL COMPACTED TO 90% RELATIVE COMPACTION CT~J Construction Testing & Engineering, Inc. ~c 1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746~955 rr[ JOB '-O I 0-136430 RETAINING WALL DRAINAGE DETAIL SC' \Lt NO SCALE DA'IE FIG R 5/17 4 ---- . " -·-APPENDIX A ... REFERENCES ,.. .. --..., ----------.. -----------.. -- ----------- --------------- -------.. -- REFERENCES I. American Society for Civil Engineers, 2010, "Minimum Design Loads for Buildings and Other Structures," ASCE/SEI 7-10. 2. ASTM, 2002, "Test Method for Laboratory Compaction Characteristics of Soil Using Modified Effort," Volume 04.08 3. Blake, T.F., 2000, "EQFAULT," Version 3.00b, Thomas F. Blake Computer Services and Software. 4. California Building Code, 2013, "California Code of Regulations, Title 24, Part 2, Volume 2 of2," California Building Standards Commission, published by ICBO, June. 5. California Division of Mines and Geology, CD 2000-003 "Digital Images of Official Maps of Alquist-Priolo Earthquake Fault Zones of California, Southern Region," compiled by Martin and Ross. 6. California Emergency Management Agency/California Geological Survey, "Tsunami Inundation Maps for Emergency Planning. 7. Frankel, A.D., Petersen, M.D., Mueller, C.S., Haller, K.M., Wheeler, R.L., Leyendecker, E.V., Wesson, R. L., Harmsen, S.C., Cramer, C.H., Perkins, D.M., Rukstales,K.S.,2002, Documentation for the 2002 update of the National Seismic Hazard Maps: U.S. Geological Survey Open-File Report 2002-420, 39p 8. Hart, Earl W., Revised 2007, "Fault-Rupture Hazard Zones in California, Alquist Priolo, Special Studies Zones Act of 1972," California Division of Mines and Geology, Special Publication 42. 9. Jennings, Charles W., 1994, "Fault Activity Map of California and Adjacent Areas" with Locations and Ages of Recent Volcanic Eruptions. 10. Kennedy, M.P. and Tan, S.S., 2007, "Geologic Map of the Oceanside 30' x 60' Quadrangle, California", California Geological Survey, Map No. 2, Plate I of 2. 11. Reichle, M., Bodin, P., and Brune, J., 1985, The June 1985 San Diego Bay Earthquake swarm [abs.]: EOS, v. 66, no. 46, p.952. 12. SEAOC, Blue Book-Seismic Design Recommendations, "Seismically Induced Lateral Earth Pressures on Retaining Structures and Basement Walls," Article 09.10.010, October 2013. 13. Seed, H.B., and R.V. Whitman, 1970, "Design of Earth Retaining Structures for Dynamic Loads," in Proceedings, ASCE Specialty Conference on Lateral Stresses in the Ground and Design of Earth-Retaining Structures, pp. 103-147, Ithaca, New York: Cornell University. --- -------.. --... - ------------------.. -- 14. Simons, R.S., 1979, Instrumental Seismicity of the San Diego area, 1934-1978, in Abbott, P.L. and Elliott, W.J., eds., Earthquakes and other perils, San Diego region: San Diego Association of Geologists, prepared for Geological Society of America field trip, November 1979, p.101-105. 15. Tan, S. S., and Giffen, D. G., 1995, "Landslide Hazards in the Northern Part of the San Diego Metropolitan Area, San Diego County, California: Oceanside and San Luis Rey Quadrangles, Landslide Hazard Identification Map No. 35", California Department of Conservation, Division of Mines and Geology, Open-File Report 95-04, State of California, Division of Mines and Geology, Sacramento, California. 16. Wood, J.H. 1973, Earthquake-Induced Soil Pressures on Structures, Report EERL 73-05 . Pasadena: California Institute of Technology. -----,,. -------- ---... --------------- , . ... .. - APPENDIXB EXPLORATION LOGS Construction Testing & Engineering, Inc. 1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955 DEFINITION OF TERMS PRIMARY DIVISIONS GRAVELS MORE THAN HALF OF COARSE FRACTION IS LARGER THAN NO. 4 SIEVE SANDS MORE THAN HALF OF COARSE FRACTION IS SMALLER THAN NO. 4 SIEVE CLEAN GRAVELS < 5% FINES GRAVELS WITH FINES CLEAN SANDS < 5% FINES SIL TS AND CLAYS LIQUID LIMIT IS LESS THAN 50 SILTS AND CLAYS LIQUID LIMIT IS GREATER THAN 50 HIGHLY ORGANIC SOILS SYMBOLS SECONDARY DIVISIONS WELL GRADED GRAVELS, GRAVEL-SAND MIXTURES LITTLE OR NO FINES POORLY GRADED GRAVELS OR GRAVEL SAND MIXTURES, LITTLE OF NO FINES SILTY GRAVELS, GRAVEL-SAND-SILT MIXTURES, NON-PLASTIC FINES CLAYEY GRAVELS, GRAVEL-SAND-CLAY MIXTURES, PLASTIC FINES WELL GRADED SANDS, GRA YELL Y SANDS, LITTLE OR NO FINES POORLY GRADED SANDS, GRA YELL Y SANDS, LITTLE OR NO FINES SILTY SANDS, SAND-SILT MIXTURES, NON-PLASTIC FINES INORGANIC SILTS, VERY FINE SANDS, ROCK FLOUR, SILTY OR CLAYEY FINE SANDS. SLIGHTLY PLASTIC CLAYEY SIL TS INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY, GRA YELL Y SANDY SILTS OR LEAN CLAYS ORGANIC SIL TS AND ORGANIC CLAYS OF LOW PLASTICITY INORGANIC SILTS, MICACEOUS OR DIATOMACEOUS FINE SANDY OR SILTY SOILS ELASTIC SIL TS INORGANIC CLAYS OF HIGH PLASTICITY, FAT CLAYS ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY, ORGANIC SIL TY CLAYS PEAT AND OTHER HIGHLY ORGANIC SOILS GRAIN SIZES BOULDERS COBBLES GRAVEL SAND SILTS AND CLAYS COARSE FINE COARSE MEDIUM FIN E 12" 3" 3/4" 4 10 40 200 CLEAR SQUARE SIEVE OPENING U.S. STANDARD SIEVE SlZE ADDITIONAL TESTS (OTHER THAN TEST PIT AND BORrNG LOG COLUMN HEADINGS) MAX-Maximum Dry Density GS-Grain Size Distribution SE-Sand Equivalent El-Expansion Index CHM-Sulfate and Chloride Content , pH, Resistivity COR -Corrosivity SD-Sample Disturbed PM-Permeability SG-Specific Gravity HA-Hydrometer Analysis AL-Atterberg Limits RV-R-Value CN-Consolidation CP-Collapse Potential HC-Hydrocollapse REM-Remolded PP-Pocket Penetrometer WA-Wash Analysis OS-Direct Shear UC-Unconfined Compression MD-Moisture/Density M-Moisture SC-Swell Compression 0 1-Organic Impurities FIGURE: BLI ,_ ,_ -.. -PROJECT: -CTEJOB NO: LOGGED BY: -0 Q. !l. -% ~ >, " "' f-I::, " -,s "' " Q. "3 > " Ii -Cl "' ----------00 -------------------------I ------.. tI -----------... ---------------------------- 0 0 ~ 0 a; c--,g Construction Testing & Engineering, Inc. 1441 Montiel Rd Ste 115, Escondido. CA 92026 Ph (760) 746-4955 C u _e, q f ~ " ~ 0 £1 Cl c ·o Cl :;: DRILLER SHEET: of DRILL METHOD: DRILLING DATE: SAMPLE METHOD: ELEVATION: "3 .0 E "' >, 0 "' ..J BORING LEGEND Laboratory Tests ,; u :E u ,; 8 ::i DESCRIPTION Block or Chunk Sample Bulk Sample Standard Penetration Test Modified Split-Barrel Drive Sampler (Cal Sampler) Thin Walled Army Corp. of Engineers Sample Groundwater Table .. --· ----------------------------------------------- '\.. -Soil Type or Classification Change -?---?---?---?---?---?---?- \__ F.ormation Change [(A~proximat~ boundari~s queried ;?)l "SM" Quotes are placed around classifications where the soils exist in situ as bedrock FIGURE: I BL2 I I I I I I I I I l I I I I I I 1111111,11 I I CJ P Construction Testing & Engineering, Inc. ~c 1441 Montiel Rd Ste 115. Escondido, CA 92026 Ph (760) 746-4955 EXCAVATOR: AJB I t I I I I I I I I PROJECT CTEJOBNO: iLOGGEDBY: PROPOSED TRIPLEX CONDOMINIUMS l0-l3643G EXCAVATION METHOD SAMPLING METHOD: HAND AUGER BULK EXCAVATION DATE: 5/9/2017 AJB C 0 u 0. ,c -E -i ~ ,-, "" .; 0 "' ..J " C ~ c,i .s !::, " -~ u 0 .0 £ ;:, c,i ~ 0. 0 " 0 :a ::i "' 0 SM 0 -- "SM" -- f----- >-5- -- "SC" I---+--- t-- t-- t·rn- t-- t-- t-- t-- t-]j- t-- t-- " 0. " ~ 0. ,-, "' f-- ELEVATION: -68 FEET BORING LOG B-1 DESCRIPTION RESIDUAL SOIL: Loose, moist, dark reddish brown, silty fine grained SAND. QUATERNARY VERY OLD PARALIC DEPOSITS: Medium dense, moist, reddish brown, silty fine grained SANDSTONE, oxidized, massive. Abundant manganese nodules Medium dense, moist, reddish brown, clayey fine grained SANDSTONE, oxidized, massive, moderately cemented. Groundwater seepage encountered at approximately 11.9 feet Total Depth: 12.5' (Refusal on gravel) Groundwater seepage encountered at approximately l 1.9 feet Laboratory Tests El I--..L.-.I--...I.-..L..-~~1...--------------------------------------....,Fl:"IJ,.G!TJ'm - I I I I I I I t I I I I 111111111111111) ll I I I I I I I I Cl~ Construction Testing & Engineering, Inc. . ~c 1441 Montiel Rd Ste 115. Escondido. CA 92026 Ph (760) 746-4955 PROJECT: PROPOSED TRIPLEX CONDOMINIUMS EXCAVATOR AJB CTEJOBNO: 10-136430 EXCAVATION METHOD HAND AUGER EXCAVATION DA TE: 5/9/2017 LOGGED BY: AJB SAMPLING METHOD: BULK ELEVATION: -68 FEET C: 0 " u -=" " "E. " c ~ E "" ~ !;: BORING LOG B-2 "->, 0 1l Laboratory Tests , "' ...J "' f--C ~ vi 0 !':, --" 0 0 :c C Cl ts ~ ! .,. ~ cc ·s vi 8 :i ·;:: Cl :; C) "' Cl DESCRIPTION SM 0 RESIDUAL SOIL: ~ -Loose, sliahtlv moist, dark brown, siltv fine Qrained SAND. "SC" ... -QUATERNARY VERY OLD PARALIC DEPOSITS: Medium dense to dense, moist, reddish brawn, clayey fine grained SANDSTONE, oxidized, massive, ~ -manganeze nodules. ... --------------~-------------------------------------------------------------------------------------------· "SM" --5-Medium dense, moist, light reddish brown, silty fine grained SANDSTONE, oxidized, massive, moderately ----------_____ ceroeatact_ ________________________________________________________________________________ "SC" --Medium dense to dense, moist, reddish brown, clayey fine grained SANDSTONE, oxidized, massive. --Gravel GS ~ - ... - -10- ... -Groundwater seepage encountered at approximately 11.6 feet. ------------___ MediUlll .dense,..wet,.gr.ay, .poorly. Q1Caded.mediu1J1.g1:ait:1ed.SANOs:r.ONE with. gi:ave~ iciable.------------ " ... -Total Deoth: 12.5' (Refusal on gravel) ~ -Groundwater seepage encountered at approximately 11.6 feet >-Is- ~ - ... - ~T7 ~ I ~ R-·, 111111 II ll II II 11111111 II 11111111111111 CJ~ Construction Testing & Engineering, Inc. ~c 1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 74~955 PROJECT PROPOSED TRIPLEX CONDOMINIUMS EXCAVATOR: AJB CTEJOBNO: 10-136430 EXCAVATION METHOD: HAND AUGER EXCAVATION DATE: 5/9/2017 LOGGED BY: AJB SAMPLING METHOD: BULK ELEVATION: -68 FEET C 0 " u E, .0 C. " t t E 00 l § ~ BORING LOG B-3 " 0 "',::' Laboratory Tests "' ..l C ~ vi .~ --" ~ u C Cl .c 'E. -"' ~ c ·;; vi §" 0 '3 ·;:::: Cl ,: =i " "' Cl DESCRIPTION SM 0 RESIDUAL SOIL: --Loose, moist, dark brown, siltv fine arained SAND. "SM" --QUATERNARY VERY OLD PARALIC DEPOSITS: Medium dense, moist, reddish brown, silty fine grained SANDSTONE, oxidized, massive, manganese GS,CHM --nodules. Gravel --Becomes dense with abundant manganese " --Total Depth: 5' (Refusal on gravel) No groundwater encountered ---- I-- Ho- I---------,s----- ,, ••• .,_' ti 1111 ti If ti If lt 11 lt Ii IA II It II ii II It II Cl~ Construction Testing & Engineering, Inc. ......!!f,,C 1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955 PROJECT PROPOSED TRIPLEX CONDOMINIUMS EXCAVATOR: AJB CTEJOBNO: 10-13643G EXCAVATION METHOD HAND AUGER EXCAVATION DA TE: 5/9/2017 LOGGEDBV: AJB SAMPLING METHOD: BULK ELEVATION: --68 FEET C 0 " u E, JO 0. " E t 'cf. "' '" ti' § C. BORING LOG B-4 e., "' 0 "' ,::, Laboratory Tests ..J " C e ,i u !::, --" .~ u ,; C Cl l -~ c ,i e--"' 0 ~ c Cl :;: ;:; 0 DESCRIPTION SM 0 RESIDUAL SOIL: --Loose, moist, dark reddish brown, silty fine grained SAND with trace gravel, roots. "SM" ... -QUATERNARY VERY OLD PARALIC DEPOSITS: Medium dense, moist, reddish brown, silty fine grained SANDSTONE with gravel, oxidized, massive. --Total Depth: 3' (Refusal on gravel) -5-No groundwater encountered -- -- ... - ... - 1-io- ... --- ... --- 1-Jj- -- -- Fll.!I IUL.i,J D_a -------------------------------------- APPENDIXC LABORATORY METHODS AND RESULTS ------------------ ------------------ APPENDIXC LABORATORY METHODS AND RESULTS Laboratory Testing Program Laboratory tests were performed on representative soil samples to detect their relative engineering properties. Tests were performed following test methods of the American Society for Testing Materials or other accepted standards. The following presents a brief description of the various test methods used. Classification Soils were classified visually according to the Unified Soil Classification System. Visual classifications were supplemented by laboratory testing of selected samples according to ASTM D2487. The soil classifications are shown on the Exploration Logs in Appendix B. Particle-Size Analysis Particle-size analyses were performed on selected representative samples according to ASTM D 422. Expansion Index Expansion testing was performed on selected samples of the matrix of the on-site soils according to ASTMD4829. Chemical Analysis Soil materials were collected with sterile sampling equipment and tested for Sulfate and Chloride content, pH, Corrosivity, and Resistivity. ----~ Construction Testing & Engineering, Inc. Cl~c --------- 1441 Montiel Rd Ste 115, Escondido. CA 92026 Ph (760) 746-4955 --EXPANSION INDEX TEST ASTMD4829 -LOCATION DEPTH EXPANSION INDEX EXPANSION -feet POTENTIAL B-1 0-10 7 VERY LOW --SULFATE -LOCATION DEPTH RESULTS feet m -B-3 0-5 28.4 -CHLORIDE -LOCATION DEPTH RESULTS feet m -B-3 0-5 13.4 --p.H. -LOCATION DEPTH RESULTS feet -B-3 0-5 8.07 -RESISTIVITY -CALIFORNIA TEST 424 -LOCATION DEPTH RESULTS feet ohms-cm -B-3 0-5 15,700 --------------LABORATORY SUMMARY CTE JOB NO. 10-13643G U. S. STANDARD SIEVE SIZE ~ ~ ~ ~ 0 0 N co~ coo 00 0 0 0 ~ ~ (") ~ (") '<t ~N (") '<t lO ~ N 100 -----. ---.-..i:: t--, ::: r--. ~ ::::::: ::---.,___ 90 -.::: r,..r-.. r-.r-. "' r,..~. 80 [' 70 \ ' ~ 60 \ (!) \ z in \ 1/) <( 50 a.. \ I-z w 0 a: 40 w ' a.. \ 30 \ 20 "'-.:: .. I-." '""i-.• 10 0 100 10 1 0.1 0.01 0.001 PARTICLE SIZE (mm) PARTICLE SIZE ANALYSIS c@ Sample Designation Sample Depth (feet) Symbol Liquid Limit (%) Plasticity lndex Classification Construction Testing & Engineering, Inc. B-2 0-1 • --SM 1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955 B-3 0-5 • --SM CTE JOB NUMBER: 10-136430 FIGURE: C-1 -------APPENDIXD -STANDARD SPECIFICATIONS FOR GRADING -, ... -------.. ---- ------------- - ------------------------------------- AppendixD Page D-1 Standard Specifications for Grading Section 1 -General Construction Testing & Engineering, Inc. presents the following standard recommendations for grading and other associated operations on construction projects. These guidelines should be considered a portion of the project specifications. Recommendations contained in the body of the previously presented soils report shall supersede the recommendations and or requirements as specified herein. The project geotechnical consultant shall interpret disputes arising out of interpretation of the recommendations contained in the soils report or specifications contained herein. Section 2 -Responsibilities of Project Personnel The geotechnical consultant should provide observation and testing services sufficient to general conformance with project specifications and standard grading practices. The geotechnical consultant should report any deviations to the client or his authorized representative. The Client should be chiefly responsible for all aspects of the project. He or his authorized representative has the responsibility of reviewing the findings and recommendations of the geotechnical consultant. He shall authorize or cause to have authorized the Contractor and/or other consultants to perform work and/or provide services. During grading the Client or his 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 associated operations on construction projects, including, but not limited to, earth work in accordance with the project plans, specifications and controlling agency requirements. Section 3 -Preconstruction Meeting A preconstruction site meeting should be arranged by the owner and/or client and should include the grading contractor, design engineer, geotechnical consultant, owner's representative and representatives of the appropriate governing authorities. Section 4 -Site Preparation The client or contractor should obtain the required approvals from the controlling authorities for the project prior, during and/or after demolition, site preparation and removals, etc. The appropriate approvals should be obtained prior to proceeding with grading operations. STANDARD SPECIFICATIONS OF GRADING Page 1 of 26 -------------------------------------- Appendix D Page D-2 Standard Specifications for Grading Clearing and grubbing should consist of the removal of vegetation such as brush, grass, woods, stumps, trees, root of trees and otherwise deleterious natural materials from the areas to be graded. Clearing and grubbing should extend to the outside of all proposed excavation and fill areas. Demolition should include removal of buildings, structures, foundations, reservoirs, utilities (including underground pipelines, septic tanks, leach fields, seepage pits, cisterns, mining shafts, tunnels, etc.) and other man-made surface and subsurface improvements from the areas to be graded. Demolition of utilities should include proper capping and/or rerouting pipelines at the project perimeter and cutoff and capping of wells in accordance with the requirements of the governing authorities and the recommendations of the geotechnical consultant at the time of demolition. Trees, plants or man-made improvements not planned to be removed or demolished should be protected by the contractor from damage or injury. Debris generated during clearing, grubbing and/or demolition operations should be wasted from areas to be graded and disposed off-site. Clearing, grubbing and demolition operations should be performed under the observation of the geotechnical consultant. Section 5 · Site Protection Protection of the site during the period of grading should be the responsibility of the contractor. Unless other provisions are made in writing and agreed upon among the concerned parties, completion of a portion of the project should not be considered to preclude that portion or adjacent areas from the requirements for site protection until such time as the entire project is complete as identified by the geotechnical consultant, the client and the regulating agencies. Precautions should be taken during the performance of site clearing, excavations and grading to protect the work site from flooding, ponding or inundation by poor or improper surface drainage. Temporary provisions should be made during the rainy season to adequately direct surface drainage away from and off the work site. Where low areas cannot be avoided, pumps should be kept on hand to continually remove water during periods ofrainfall. Rain related damage should be considered to include, but may not be limited to, erosion, silting, saturation, swelling, structural distress and other adverse conditions as determined by the geotechnical consultant. Soil adversely affected should be classified as unsuitable materials and should be subject to overexcavation and replacement with compacted fill or other remedial grading as recommended by the geotechnical consultant. ST AND ARD SPECIFICATIONS OF GRADING Page 2 of 26 -... ------------------------------------ Appendix D Page D-3 Standard Specifications for Grading The contractor should be responsible for the stability of all temporary excavations. Recommendations by the geotechnical consultant pertaining to temporary excavations ( e.g., backcuts) are made in consideration of stability of the completed project and, therefore, should not be considered to preclude the responsibilities of the contractor. Recommendations by the geotechnical consultant should not be considered to preclude requirements that are more restrictive by the regulating agencies. The contractor should provide during periods of extensive rainfall plastic sheeting to prevent unprotected slopes from becoming saturated and unstable. When deemed appropriate by the geotechnical consultant or governing agencies the contractor shall install checkdams, desilting basins, sand bags or other drainage control measures. In relatively level areas and/or slope areas, where saturated soil and/or erosion gullies exist to depths of greater than 1.0 foot; they should be overexcavated and replaced as compacted fill in accordance with the applicable specifications. Where affected materials exist to depths of 1.0 foot or less below proposed finished grade, remedial grading by moisture conditioning in-place, followed by thorough recompaction in accordance with the applicable grading guidelines herein may be attempted. If the desired results are not achieved, all affected materials should be overexcavated and replaced as compacted fill in accordance with the slope repair recommendations herein. If field conditions dictate, the geotechnical consultant may recommend other slope repair procedures. Section 6 -Excavations 6.1 Unsuitable Materials Materials that are unsuitable should be recommendations of the geotechnical consultant. excavated under observation and Unsuitable materials include, but may not be limited to, dry, loose, soft, wet, organic compressible natural soils and fractured, weathered, soft bedrock and nonengineered or otherwise deleterious fill materials. Material identified by the geotechnical consultant as unsatisfactory due to its moisture conditions should be overexcavated; moisture conditioned as needed, to a uniform at or above optimum moisture condition before placement as compacted fill. If during the course of grading adverse geotechnical conditions are exposed which were not anticipated in the preliminary soil report as determined by the geotechnical consultant additional exploration, analysis, and treatment of these problems may be recommended. STANDARD SPECIFICATIONS OF GRADING Page 3 of 26 -------------------------------------- AppendixD Page D-4 Standard Specifications for Grading 6.2 Cut Slopes Unless otherwise recommended by the geotechnical consultant and approved by the regulating agencies, permanent cut slopes should not be steeper than 2: 1 (horizontal: vertical). The geotechnical consultant should observe cut slope excavation and if these excavations expose loose cohesionless, significantly fractured or otherwise unsuitable material, the materials should be overexcavated and replaced with a compacted stabilization fill. If encountered specific cross section details should be obtained from the Geotechnical Consultant. When extensive cut slopes are excavated or these cut slopes are made in the direction of the prevailing drainage, a non-erodible diversion swale (brow ditch) should be provided at the top of the slope. 6.3 Pad Areas All Jot pad areas, including side yard terrace contammg both cut and fill materials, transitions, located Jess than 3 feet deep should be overexcavated to a depth of 3 feet and replaced with a uniform compacted fill blanket of 3 feet. Actual depth of overexcavation may vary and should be delineated by the geotechnical consultant during grading, especially where deep or drastic transitions are present. For pad areas created above cut or natural slopes, positive drainage should be established away from the top-of-slope. This may be accomplished utilizing a berm drainage swale and/or an appropriate pad gradient. A gradient in soil areas away from the top-of-slopes of 2 percent or greater is recommended. Section 7 -Compacted Fill All fill materials should have fill quality, placement, conditioning and compaction as specified below or as approved by the geotechnical consultant. 7.1 Fill Material Quality Excavated on-site or import materials which are acceptable to the geotechnical consultant may be utilized as compacted fill, provided trash, vegetation and other deleterious materials are removed prior to placement. All import materials anticipated for use on-site should be sampled tested and approved prior to and placement is in conformance with the requirements outlined. STANDARD SPECIFICATIONS OF GRADING Page4 of 26 --------------- ---- ----------------- AppendixD Page D-5 Standard Specifications for Grading Rocks 12 inches in maximum and smaller may be utilized within compacted fill provided sufficient fill material is placed and thoroughly compacted over and around all rock to effectively fill rock voids. The amount of rock should not exceed 40 percent by dry weight passing the 3/4-inch sieve. The geotechnical consultant may vary those requirements as field conditions dictate. Where rocks greater than 12 inches but less than four feet of maximum dimension are generated during grading, or otherwise desired to be placed within an engineered fill, special handling in accordance with the recommendations below. Rocks greater than four feet should be broken down or disposed off-site. 7 .2 Placement of Fill Prior to placement of fill material, the geotechnical consultant should observe and approve the area to receive fill. After observation and approval, the exposed ground surface should be scarified to a depth of 6 to 8 inches. The scarified material should be conditioned (i.e. moisture added or air dried by continued discing) to achieve a moisture content at or slightly above optimum moisture conditions and compacted to a minimum of 90 percent of the maximum density or as otherwise recommended in the soils report or by appropriate government agencies. Compacted fill should then be placed in thin horizontal lifts not exceeding eight inches in loose thickness prior to compaction. Each lift should be moisture conditioned as needed, thoroughly blended to achieve a consistent moisture content at or slightly above optimum and thoroughly compacted by mechanical methods to a minimum of 90 percent of laboratory maximum dry density. Each lift should be treated in a like manner until the desired finished grades are achieved. The contractor should have suitable and sufficient mechanical compaction equipment and watering apparatus on the job site to handle the amount of fill being placed in consideration of moisture retention properties of the materials and weather conditions. When placing fill in horizontal lifts adjacent to areas sloping steeper than 5: I (horizontal: vertical), horizontal keys and vertical benches should be excavated into the adjacent slope area. Keying and benching should be sufficient to provide at least six-foot wide benches and a minimum of four feet of vertical bench height within the firm natural ground, firm bedrock or engineered compacted fill. No compacted fill should be placed in an area after keying and benching until the geotechnical consultant has reviewed the area. Material generated by the benching operation should be moved sufficiently away from STANDARD SPECIFICATIONS OF GRADING Page 5 of 26 ---- ------------------------ -------- Appendix D Page D-6 Standard Specifications for Grading the bench area to allow for the recommended review of the horizontal bench prior to placement of fill. Within a single fill area where grading procedures dictate two or more separate fills, temporary slopes (false slopes) may be created. When placing fill adjacent to a false slope, benching should be conducted in the same manner as above described. At least a 3-foot vertical bench should be established within the firm core of adjacent approved compacted fill prior to placement of additional fill. Benching should proceed in at least 3-foot vertical increments until the desired finished grades are achieved. Prior to placement of additional compacted fill following an overnight or other grading delay, the exposed surface or previously compacted fill should be processed by scarification, moisture conditioning as needed to at or slightly above optimum moisture content, thoroughly blended and recompacted to a minimum of 90 percent of laboratory maximum dry density. Where unsuitable materials exist to depths of greater than one foot, the unsuitable materials should be over-excavated. Following a period of flooding, rainfall or overwatering by other means, no additional fill should be placed until damage assessments have been made and remedial grading performed as described herein. Rocks 12 inch in maximum dimension and smaller may be utilized in the compacted fill provided the fill is placed and thoroughly compacted over and around all rock. No oversize material should be used within 3 feet of finished pad grade and within 1 foot of other compacted fill areas. Rocks 12 inches up to four feet maximum dimension should be placed below the upper 10 feet of any fill and should not be closer than 15 feet to any slope face. These recommendations could vary as locations of improvements dictate. Where practical, oversized material should not be placed below areas where structures or deep utilities are proposed. Oversized material should be placed in windrows on a clean, overexcavated or unyielding compacted fill or firm natural ground surface. Select native or imported granular soil (S.E. 30 or higher) should be placed and thoroughly flooded over and around all windrowed rock, such that voids are filled. Windrows of oversized material should be staggered so those successive strata of oversized material are not in the same vertical plane. It may be possible to dispose of individual larger rock as field conditions dictate and as recommended by the geotechnical consultant at the time of placement. STANDARD SPECIFICATIONS OF GRADING Page 6 of 26 -------------------------------------- Appendix D Page D-7 Standard Specifications for Grading The contractor should assist the geotechnical consultant and/or his representative by digging test pits for removal determinations and/or for testing compacted fill. The contractor should provide this work at no additional cost to the owner or contractor's client. Fill should be tested by the geotechnical consultant for compliance with the recommended relative compaction and moisture conditions. Field density testing should conform to ASTM Method of Test D 1556-00, D 2922-04. Tests should be conducted at a minimum of approximately two vertical feet or approximately 1,000 to 2,000 cubic yards of fill placed. Actual test intervals may vary as field conditions dictate. Fill found not to be in conformance with the grading recommendations should be removed or otherwise handled as recommended by the geotechnical consultant. 7.3 Fill Slopes Unless otherwise recommended by the geotechnical consultant and approved by the regulating agencies, permanent fill slopes should not be steeper than 2: I (horizontal: vertical). Except as specifically recommended in these grading guidelines compacted fill slopes should be over-built two to five feet and cut back to grade, exposing the firm, compacted fill inner core. The actual amount of overbuilding may vary as field conditions dictate. If the desired results are not achieved, the existing slopes should be overexcavated and reconstructed under the guidelines of the geotechnical consultant. The degree of overbuilding shall be increased until the desired compacted slope surface condition is achieved. Care should be taken by the contractor to provide thorough mechanical compaction to the outer edge of the overbuilt slope surface. At the discretion of the geotechnical consultant, slope face compaction may be attempted by conventional construction procedures including backrolling. The procedure must create a firmly compacted material throughout the entire depth of the slope face to the surface of the previously compacted firm fill intercore. During grading operations, care should be taken to extend compactive effort to the outer edge of the slope. Each lift should extend horizontally to the desired finished slope surface or more as needed to ultimately established desired grades. Grade during construction should not be allowed to roll off at the edge of the slope. It may be helpful to elevate slightly the outer edge of the slope. Slough resulting from the placement of individual lifts should not be allowed to drift down over previous lifts. At intervals not STANDARD SPECIFICATIONS OF GRADING Page 7 of 26 -------------------------------------- AppendixD Page D-8 Standard Specifications for Grading exceeding four feet in vertical slope height or the capability of available equipment, whichever is less, fill slopes should be thoroughly dozer trackrolled. For pad areas above fill slopes, positive drainage should be established away from the top-of-slope. This may be accomplished using a berm and pad gradient of at least two percent. Section 8 -Trench Backfill Utility and/or other excavation of trench backfill should, unless otherwise recommended, be compacted by mechanical means. Unless otherwise recommended, the degree of compaction should be a minimum of 90 percent of the laboratory maximum density. Within slab areas, but outside the influence of foundations, trenches up to one foot wide and two feet deep may be backfilled with sand and consolidated by jetting, flooding or by mechanical means. If on-site materials are utilized, they should be wheel-rolled, tamped or otherwise compacted to a firm condition. For minor interior trenches, density testing may be deleted or spot testing may be elected if deemed necessary, based on review of backfill operations during construction. If utility contractors indicate that it is undesirable to use compaction equipment in close proximity to a buried conduit, the contractor may elect the utilization of light weight mechanical compaction equipment and/or shading of the conduit with clean, granular material, which should be thoroughly jetted in-place above the conduit, prior to initiating mechanical compaction procedures. Other methods of utility trench compaction may also be appropriate, upon review of the geoteclmical consultant at the time of construction. In cases where clean granular materials are proposed for use in lieu of native materials or where flooding or jetting is proposed, the procedures should be considered subject to review by the geoteclmical consultant. Clean granular backfill and/or bedding are not recommended in slope areas. Section 9 -Drainage Where deemed appropriate by the geoteclmical consultant, canyon subdrain systems should be installed in accordance with CTE's recommendations during grading. Typical subdrains for compacted fill buttresses, slope stabilization or sidehill masses, should be installed in accordance with the specifications. STANDARD SPECIFICATIONS OF GRADING Page 8 of 26 ---.. ---------------------------------- Appendix D Page D-9 Standard Specifications for Grading Roof, pad and slope drainage should be directed away from slopes and areas of structures to suitable disposal areas via non-erodible devices (i.e., gutters, downspouts, and concrete swales). For drainage in extensively landscaped areas near structures, (i.e., within four feet) a minimum of 5 percent gradient away from the structure should be maintained. Pad drainage of at least 2 percent should be maintained over the remainder of the site. Drainage patterns established at the time of fine grading should be maintained throughout the life of the project. Property owners should be made aware that altering drainage patterns could be detrimental to slope stability and foundation performance. Section IO -Slope Maintenance I 0.1 -Landscape Plants To enhance surficial slope stability, slope planting should be accomplished at the completion of grading. Slope planting should consist of deep-rooting vegetation requiring little watering. Plants native to the southern California area and plants relative to native plants are generally desirable. Plants native to other semi-arid and arid areas may also be appropriate. A Landscape Architect should be the best party to consult regarding actual types of plants and planting configuration. I 0.2 -Irrigation Irrigation pipes should be anchored to slope faces, not placed in trenches excavated into slope faces. Slope irrigation should be minimized. If automatic timing devices are utilized on irrigation systems, provisions should be made for interrupting normal irrigation during periods of rainfall. 10. 3 -Repair As a precautionary measure, plastic sheeting should be readily available, or kept on hand, to protect all slope areas from saturation by periods of heavy or prolonged rainfall. This measure is strongly recommended, beginning with the period prior to landscape planting. If slope failures occur, the geotechnical consultant should be contacted for a field review of site conditions and development of recommendations for evaluation and repair. If slope failures occur as a result of exposure to period of heavy rainfall, the failure areas and currently unaffected areas should be covered with plastic sheeting to protect against additional saturation. STANDARD SPECIFICATIONS OF GRADING Page 9 of 26 ----------------.. -------- ------------ Appendix D Page D-10 Standard Specifications for Grading In the accompanying Standard Details, appropriate repair procedures are illustrated for superficial slope failures (i.e., occurring typically within the outer one foot to three feet of a slope face). STANDARD SPECIFICATIONS OF GRADING Page 10 of 26 -.. -.. ---- -------... ------., .. -.. ----- --... .. , ... FINISH CUT SLOPE ------- BENCHING FILL OVER NATURAL SURFACE OF FIRM EARTH MATERIAL FILL SLOPE 2%MIN - 10' TYPICAL 15' MIN. (INCLINED 2% MIN. INTO SLOPE) BENCHING FILL OVER CUT SURFACE OF FIRM EARTH MATERIAL FINISH FILL SLOPE 10' TYPICAL 15' MIN OR STABILITY EQUIVALENT PER SOIL ENGINEERING (INCLINED 2% MIN. INTO SLOPE) NOTTO SCALE BENCHING FOR COMPACTED FILL DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 11 of 26 --- -------• .. ---------------... --.. ... ------.. -- MINIMUM DOWNSLOPE KEY DEPTH TOE OF SLOPE SHOWN ON GRADING PLAN FILL ------------------~ ----..... "'i~~\l'I --- -~~,.,r -- ---~~p.~ -- --... p.~\: ---5\)X' ---\)~ -~'r-----------~ .----1 O' TYPICAL BENCH // ---WIDTH VARIES A1 --- / 1 --- / ---- 2% MIN --- 15' MINIMUM BASE KEY WIDTH COMPETENT EARTH MATERIAL TYPICAL BENCH HEIGHT PROVIDE BACKDRAIN AS REQUIRED PER RECOMMENDATIONS OF SOILS ENGINEER DURING GRADING WHERE NATURAL SLOPE GRADIENT IS 5:1 OR LESS, BENCHING IS NOT NECESSARY. FILL IS NOT TO BE PLACED ON COMPRESSIBLE OR UNSUITABLE MATERIAL. NOT TO SCALE 4' FILL SLOPE ABOVE NATURAL GROUND DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 12 of 26 1111 lltl 11(1 llfl li'II IIII II II IIII If 1111 en ~ z CJ )> ::,J CJ en 1l 1l m Ill (') IC -CD I! ..... (') Col~ 0 -... 0 I\) z c, en "T1 0 ::,J Ci) ~ Q z Ci) - REMOVE All TOPSOIL, COLLUVIUM, AND CREEP MATERIAL FROM TRANSITION CUT/Fill CONTACT SHOWN ON GRADING PLAN CUT/Fill CONTACT SHOWN ON "AS-BUILT" NATURAL~ -TOPOGRAPHY __ ----------_ --CUT SLOPE* Fill ------------li:.~o\JE--- _____ ~oc~E.E.~-~ --- ----co\.\.u\JIU~ r,i ...,,--- ,0~sol\., ----~I f. ---4· I -TYPICAL 15' MINIMUM NOTTO SCALE 10'TYPICAL BEDROCK OR APPROVED FOUNDATION MATERIAL *NOTE: CUT SLOPE PORTION SHOULD BE MADE PRIOR TO PLACEMENT OF Fill FILL SLOPE ABOVE CUT SLOPE DETAIL ---- -... ----.. --------------------------.. --- [ SURFACEOF -----------------~~~:~~~NT ----..... , /;" ,', COMPACTED FILL /'/ \ \ / I \ I TYPICAL BENCHING \' / ,, // ,.__.. ,_,,,, A--~ ' / REMOVE UNSUITABLE SEE DETAIL BELOW DETAIL MINIMUM 9 FT3 PER LINEAR FOOT OF APPROVED FILTER MATERIAL ...-. CALTRANS CLASS 2 PERMEABLE MATERIAL FILTER MATERIAL TO MEET FOLLOWING SPECIFICATION OR APPROVED EQUAL: L..----1---->1. 14" MINIMUM SIEVE SIZE PERCENTAGE PASSING 1" ¾" 100 90-100 40-100 25-40 18-33 5-15 0-7 MATERIAL INCLINE TOWARD DRAIN AT 2% GRADIENT MINIMUM MINIMUM 4" DIAMETER APPROVED PERFORATED PIPE (PERFORATIONS DOWN) 6" FILTER MATERIAL BEDDING APPROVED PIPE TO BE SCHEDULE 40 POLY-VINYL-CHLORIDE (P.V.C.) OR APPROVED EQUAL. MINIMUM CRUSH STRENGTH 1000 psi PIPE DIAMETER TO MEET THE FOLLOWING CRITERIA, SUBJECT TO FIELD REVIEW BASED ON ACTUAL GEOTECHNICAL CONDITIONS ENCOUNTERED DURING GRADING LENGTH OF RUN INITIAL 500' 500' TO 1500' > 1500' PIPE DIAMETER 4" 6" 8" N0.4 N0.8 NO. 30 NO. 50 NO. 200 0-3 NOTTO SCALE TYPICAL CANYON SUBDRAIN DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 14 of 26 --------------------... -------... ----- --- CANYON SUBDRAIN DETAILS TYPICAL BENCHING SURFACE OF COMPETENT MATERIAL REMOVE UNSUITABLE MATERIAL SEE DETAILS BELOW TRENCH DETAILS INCLINE TOWARD DRAIN AT 2% GRADIENT MINIMUM OPTIONAL V-DITCH DETAIL MINIMUM 9 FT' PER LINEAR FOOT OF APPROVED DRAIN MATERIAL 0 24" MINIMUM MINIMUM 9 FT' PER LINEAR FOOT OF APPROVED DRAIN MATERIAL 60' TO 90' MIRAFI 140N FABRIC OR APPROVED EQUAL APPROVED PIPE TO BE SCHEDULE 40 POLY- VINYLCHLORIDE (P.V.C.) OR APPROVED EQUAL. MINIMUM CRUSH STRENGTH 1000 PSI. DRAIN MATERIAL TO MEET FOLLOWING SPECIFICATION OR APPROVED EQUAL: PIPE DIAMETER TO MEET THE FOLLOWING CRITERIA, SUBJECT TO FIELD REVIEW BASED ON ACTUAL GEOTECHNICAL CONDITIONS ENCOUNTERED DURING GRADING SIEVE SIZE 1 ½· 1" ¾" ¾" NO. 200 PERCENTAGE PASSING 88-100 5-40 0-17 0-7 0-3 LENGTH OF RUN INITIAL 500' 500' TO 1500' > 1500' NOTTO SCALE GEOFABRIC SUBDRAIN STANDARD SPECIFICATIONS FOR GRADING Page 15 of 26 PIPE DIAMETER 4" 6" 8" -----------------------.. -.. ------------ FRONT VIEW :-... :-.. ~':-.-.'!·.:· : .... :.-... CONCRETE -----i~· ;, . ;,.""·_; t• ......... .. CUT-OFF WALL ,!·., r ,.~·.:-''!·; '!··.,, !•., .. ,;, .•, • ;,-:"'.•;,L•;, I 6"Min. ,!.>? . •,'•.-. .-,'•• ..... . __..... ............ ---1~ SUBDRAIN PIPE.,,,.,..-c ;._: •·,·· .. _.. •·' ; 6" Min . ... -•.-... ' ...... ' ,. -24"Min. - 6"Min. SIDE VIEW ---j 12" Min.~ 6" Min. CONCRETE CUT-OFF WALL __ _,.•°"" ... ':.-.,. . .. • ... 6"Min . -------7liilllillm,------i:· .. · ........ · ' .. • ... .. ,, NOT TO SCALE RECOMMENDED SUBDRAIN CUT-OFF WALL STANDARD SPECIFICATIONS FOR GRADING Page 16 of 26 ---------------------... ---------------- FRONT VIEW SUBDRAIN OUTLET PIPE (MINIMUM 4" DIAMETER) SIDE VIEW ALL BACKFILL SHOULD BE COMPACTED IN CONFORMANCE WITH PROJECT t---24" Min. SPECIFICATIONS. COMPACTION EFFORT ------.J SHOULD NOT DAMAGE STRUCTURE t---24" Min. NOTE: HEADWALL SHOULD OUTLET AT TOE OF SLOPE OR INTO CONTROLLED SURFACE DRAINAGE DEVICE ALL DISCHARGE SHOULD BE CONTROLLED THIS DETAIL IS A MINIMUM DESIGN AND MAY BE MODIFIED DEPENDING UPON ENCOUNTERED CONDITIONS AND LOCAL REQUIREMENTS NOT TO SCALE 24"Min. 12" TYPICAL SUBDRAIN OUTLET HEADWALL DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 17 of 26 4" DIAMETER PE RF ORA TED PIPE BACKDRAIN 4" DIAMETER NON-PERFORATED PIPE LATERAL DRAIN SLOPE PER PLAN FILTER MATERIAL 2%MI BENCHING H/2 AN ADDITIONAL BACKDRAIN AT MID-SLOPE WILL BE REQUIRED FOR SLOPE IN EXCESS OF 40 FEET HIGH. KEY-DIMENSION PER SOILS ENGINEER (GENERALLY 1/2 SLOPE HEIGHT, 15' MINIMUM) DIMENSIONS ARE MINIMUM RECOMMENDED NOT TO SCALE TYPICAL SLOPE STABILIZATION FILL DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 18 of 26 4" DIAMETER PERFORATED PIPE BACKDRAIN 4" DIAMETER NON-PERFORATED PIPE LATERAL DRAIN SLOPE PER PLAN FILTER MATERIAL 2%M H/2 ADDITIONAL BACKDRAIN AT MID-SLOPE WILL BE REQUIRED FOR SLOPE IN EXCESS OF 40 FEET HIGH. KEY-DIMENSION PER SOILS ENGINEER DIMENSIONS ARE MINIMUM RECOMMENDED NOT TO SCALE TYPICAL BUTTRESS FILL DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 19 of 26 20' MAXIMUM FINAL LIMIT OF EXCAVATION DAYLIGHT LINE FINISH PAD OVEREXCAVATE 3' AND REPLACE WITH COMPACTED FILL OVEREXCAVATE OVERBURDEN (CREEP-PRONE) COMPETENT BEDROCK TYPICAL BENCHING LOCATION OF BACKDRAIN AND OUTLETS PER SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST DURING GRADING. MINIMUM 2% FLOW GRADIENT TO DISCHARGE LOCATION. EQUIPMENT WIDTH (MINIMUM 15') NOT TO SCALE DAYLIGHT SHEAR KEY DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 20 of 26 PROPOSED GRADING BASE WIDTH "W" DETERMINED BY SOILS ENGINEER NATURAL GROUND COMPACTED FILL NOT TO SCALE PROVIDE BACKDRAIN, PER BACKDRAIN DETAIL. AN ADDITIONAL BACKDRAIN AT MID-SLOPE WILL BE REQUIRED FOR BACK SLOPES IN EXCESS OF 40 FEET HIGH. LOCATIONS OF BACKDRAINS AND OUTLETS PER SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST DURING GRADING. MINIMUM 2% FLOW GRADIENT TO DISCHARGE LOCATION. TYPICAL SHEAR KEY DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 21 of 26 FINISH SURFACE SLOPE 3 FT3 MINIMUM PER LINEAR FOOT APPROVED FILTER ROCK* CONCRETE COLLAR PLACED NEAT A 2.0% MINIMUM GRADIENT A 4" MINIMUM DIAMETER SOLID OUTLET PIPE SPACED PER SOIL ENGINEER REQUIREMENTS COMPACTED FILL 4" MINIMUM APPROVED PERFORATED PIPE** (PERFORATIONS DOWN) MINIMUM 2% GRADIENT TO OUTLET DURING GRADING TYPICAL BENCH INCLINED **APPROVED PIPE TYPE: MINIMUM 12" COVER SCHEDULE 40 POLYVINYL CHLORIDE (P.V.C.) OR APPROVED EQUAL. MINIMUM CRUSH STRENGTH 1000 PSI BENCHING TOWARD DRAIN DETAIL A-A 12" TEMPORARY FILL LEVEL MINIMUM 4" DIAMETER APPROVED SOLID OUTLET PIPE MINIMUM *FILTER ROCK TO MEET FOLLOWING SPECIFICATIONS OR APPROVED EQUAL: SIEVE SIZE 1" ¾" ¾" N0.4 NO. 30 NO. 50 NO. 200 PERCENTAGE PASSING 100 90-100 40-100 25-40 5-15 0-7 0-3 NOT TO SCALE TYPICAL BACKDRAIN DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 22 of 26 FINISH SURFACE SLOPE MINIMUM 3 FT3 PER LINEAR FOOT OPEN GRADED AGGREGATE" TAPE AND SEAL AT COVER CONCRETE COLLAR PLACED NEAT COMPACTED FILL A 2.0% MINIMUM GRADIENT A MINIMUM 4" DIAMETER SOLID OUTLET PIPE SPACED PER SOIL ENGINEER REQUIREMENTS MINIMUM 12" COVER *NOTE: AGGREGATE TO MEET FOLLOWING SPECIFICATIONS OR APPROVED EQUAL: SIEVE SIZE PERCENTAGE PASSING 1 ½" 100 1" 5-40 ¾" 0-17 ¾" 0-7 NO. 200 0-3 TYPICAL BENCHING DETAIL A-A 12" MINIMUM NOT TO SCALE MIRAFI 140N FABRIC OR APPROVED EQUAL 4" MINIMUM APPROVED PERFORATED PIPE (PERFORATIONS DOWN) MINIMUM 2% GRADIENT TO OUTLET BENCH INCLINED TOWARD DRAIN TEMPORARY FILL LEVEL MINIMUM 4" DIAMETER APPROVED SOLID OUTLET PIPE BACKDRAIN DETAIL (GEOFRABIC) STANDARD SPECIFICATIONS FOR GRADING Page 23 of 26 l FILL SLOPE 1 SOIL SHALL BE PUSHED OVER ROCKS AND FLOODED INTO VOIDS. COMPACT AROUND AND OVER EACH WINDROW. CLEAR ZONE __/ STACK BOULDERS END TO END. DO NOT PILE UPON EACH OTHER. 10' 0 0 0 ----~/L_-:----________ _.--;---:-- COMPETENT MATERIAL NOT TO SCALE ROCK DISPOSAL DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 24 of 26 STAGGER ROWS FINISHED GRADE BUILDING 10' SLOPE FACE NO OVERSIZE, AREA FOO_R FOUNDATION, UTILITIES, AND SWIMMING POOLS ~ 0 0 0 ~ 4·C-. WINDROW~ 5' MINIMUM OR BELOW DEPTH OF DEEPEST UTILITY TRENCH (WHICHEVER GREATER) TYPICAL WINDROW DETAIL (EDGE VIEW) GRANULAR SOIL FLOODED TO FILL VOIDS HORIZONTALLY PLACED COMPACTION FILL PROFILE VIEW NOT TO SCALE ROCK DISPOSAL DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 25 of 26 0 -----------------------------------... -- GENERAL GRADING RECOMMENDATIONS CUT LOT -,------------------=::::;:::,.----,ORIGINAL GROUND ----- 5' 3'MIN ---------UNWEATHERED BEDROCK OVEREXCAVATE AND REGRADE ... --- COMPACTED FILL ... ---......... --- CUT/FILL LOT (TRANSITION) --- UNWEATHERED BEDROCK NOT TO SCALE TRANSITION LOT DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 26 of 26 ___...-ORIGINAL __..--_ .,. GROUND ...... ... ... 'MIN 3'MIN OVEREXCAVATE AND REGRADE -------------------------------------- APPENDIXE C.4-1 WORKSHEET Worksheet C.4-1: Categorization oflnfiltration Feasibility Condition Categorization of Infiltration Feasibility Condition Worksheet C.4-1 Part 1 -Full Infiltration Feasibility Screening Criteria Would infiltration of the full design volume be feasible from a physical perspective without any undesirable consequences that cannot be reasonably mitigated? Criteria Screening Question Yes No 1 Is the estimated reliable infiltration rate below proposed facility locations greater than 0.5 inches per hour? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2 and Appendix D. X Provide basis: The NRCS soils across the site are all Type B soils with medium surface runoff. The site soils are generally consistent with the NRCS mapped soil types based on site explorations and percolation testing. Quaternary Old Paralic Deposits underlie the entire site and are anticipated at the base of the proposed basins. Four percolation tests were completed within the Old Paralic Deposits. The calculated infiltration rates (with an applied factor of safety of two) ranged from 0.0 I to 0.15 inch per hour. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability. 2 Can infiltration greater than 0.5 inches per hour be allowed without increasing risk of geotechnical hazards (slope stability, groundwater mounding, utilities, or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2. X Provide basis: Provided the basins are constructed in the areas with favorable penneability (Figure 2) and adequately set back from proposed structural improvements, risk of geotechnical hazards will not be significantly increased. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability. C-11 Appendix C: Geotechnical and Groundwater Investigation Requirements Worksheet C.4-1 Page 4 of 4 Criteria Screening Question 7 Can Infiltration in any appreciable quantity be allowed without posing significant risk for groundwater related concerns (shallow water table, storm water pollutants or other factors)? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. Yes No X Provide basis: According to Geotracker, the nearest known "Open" LUST cleanup site is over 4.800 feet away from the site. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates. 8 Can infiltration be allowed without violating downstream water rights? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. X Provide basis: The nearest down gradient surface waters are the Buena Vista Lagoon which is over 2,300 feet from the site. Due to the significant distance to the lagoon it is unlikely to be impacted by infiltrating site water. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates. If all answers from row 1-4 are yes then partial infiltration design is potentially feasible. Part 2 The feasibility screening category is Partial Infiltration. Result* If any answer from row 5-8 is no, then infiltration of any volume is considered tu be infeasible within the drainage area. The feasibility screening category is No Infiltration. Partial *To be completed usmg gathered stte mformatlon and best professional Judgment cons1denng the definition of MEP m the MS4 Permit. Additional testing and/ or studies may be required by City Engineer to substantiate findings C-14 Appendix C: Geotechnical and Groundwater Investigation Requirements Worksheet C.4-1 Page 2 of 4 Criteria Screening Question 3 Can infiltration greater than 0.5 inches per hour be allowed without increasing risk of groundwater contamination (shallow water table, storm water pollutants or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. Yes No X Provide basis: According to Geotracker, the nearest known "Open" LUST cleanup site is over 4,800 feet away from the site. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability. 4 Can infiltration greater than 0.5 inches per hour be allowed without causing potential water balance issues such as change of seasonality of ephemeral streams or increased discharge of contaminated groundwater to surface waters? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. X Provide basis: The nearest down gradient surface waters are the Buena Vista Lagoon which is over 2,300 feet from the site. Due to the significant distance to the lagoon it is unlikely to be impacted by infiltrating site water. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability. Part 1 If all answers to rows 1 -4 are "Yes" a full infiltration design is potentially feasible. The feasibility screening category is Full Infiltration Result* If any answer from row 1-4 is "No", infiltration may be possible to some extent but would not generally be feasible or desirable to achieve a "full infiltration" design. Proceed to Part 2 No Full *To be completed usmg gathered slte information and best profess10nal Judgment cons1denng the definition of MEP rn the MS4 Permit. Additional testing and/ or studies may be required by City Engineer to substantiate findings. C-12 Appendix C: Geotechnical and Groundwater Investigation Requirements Worksheet C.4-1 Page 3 of 4 Part 2 -Partial Infiltration vs. No Infiltration Feasibility Screening Criteria Would infiltration of water in any appreciable amount be physically feasible without any negative consequences that cannot be reasonably mitigated? Criteria Screening Question 5 Do soil and geologic conditions allow for infiltration in any appreciable rate or volume? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2 and Appendix D. Yes X No Provide basis: Based on the working draft version of Appendix C. it is CTE's understanding that the lower limit of partial infiltration is 0.05 inches/hour. The majority of the site exceeds this rate, therefore partial infiltration is possible. Summarize findings of studies; provide reference tu studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates. 6 Can Infiltration in any appreciable quantity be allowed without increasing risk of geotechnical hazards (slope stability, groundwater mounding, utilities, or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2. X Provide basis: Provided the basins are constructed in the areas with favorable permeability (Figure 2) and adequately set back from proposed structural improvements, risk of geotechnical hazards will not be significantly increased. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates. C-13