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Home My WebLink AboutCDP 02-35; HENDRIX SECOND DWELLING UNIT; PRELIMINARY GEOTECHNICAL EVALUATION; 2002-07-29,.·. ·' ~ ' . 1,, ·',•, l ·:·· . , '·~ ·,, .. -: -~ ,.•, ,• .-,,, 1:'·. ' ... " ~, :;1~-.:~· : \ . ·,.:• . ' . ,_,--' ~. __ ' , .;., '· ,,,;, ·:, • 'I--·,•,.! ,-s ~ ,: .. ' ~-f' ', ' ' ' C • J-t_"' ,./; • ' !"' . .... ,, ,,, '··:' ,"\·. . ;, .,, ·,,· ..., .. ,., ' : ~ •" ' < ' _,,.,: . ~ ; , .. -,,., .' .·· ·-·: '' ' , .. . .: ~ ; '',,:,,':· ·;_ . , ,.,· ··.·) ,_-' ' '~·· :., '' ,;_ .. · ' .· .. , ~ L, ... , •, '; ' -:~ •• , · .. -.·.4 :·, ;•;: ·, : " ' ·,·;·~ . ",_• ' .. '' ,•,I'• 'I ... , '• .· -i •• ' -s.'·: .· ·':'· ·. ~' '·, ': • '·_.. f .~.,,,. -' "\, ,,., .. ,,.., ' .. _. '... . ,':(:; 'I I ':·;· ,...,_ .. . •,. -~\. ·: . . ~ • 1 • r ,:,:-! 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' ·~ .J ·,.' ... ·-:., • ·,-_ I•: . ...,,...,:•. ;.. .:· ' ,,. ·-· • ·'<" ~ • .. · :> . : .. ,, :: . ~ , ·,· .,· . ,_, , ,,' ,1' .·.·,· I,,,, ·,f : -..:··-~= : ',, -;, A,,".•' : .... , : ._ ... ~ ·, I -·,,,,;'? -, ..... , •,,, .·f 1'.' ,' . ,.',,' ,, ' . ,:. '. .} .·-. ·' r'., :,,- I I I I I I I- I I I .I I I I ·., I I I I ·1 Geotechnical • Geologic • Environmental 5741 Palmer Way • Carlsbad, California 92008 • (760) 438-3155 • FAX (760) 931-0915 July 29, 2002 W.0. 3344-A-SC Mr. Ed Hendrix 470 Chinquapin Avenue Carlsbad, California 92008 Subject: Preliminary Geotechnical Evaluation, 470 Chinquapin Avenue, Carlsbad, San Diego County, California Dear Mr. Hendrix:· In accordance with your request, GeoSoils, Inc. (GSI) is pleased to present the results of our preliminary geotechnical evaluation of the subject site. The purpose of our investigation was to evaluatethe geologic and geotechnical conditions of the site and their effects on the proposed site development for construction, from a geotechnical standpoint. EXECUTIVE SUMMARY Based on our field exploration, geologic and geotechnical engineering analysis, the ·proposed development appears feasible from a geotechnical and geologic viewpoint, provided that the recommendations presented herein are ·properly incorporated into the design and construction of the project. The most significant elements of our study are summarized below: • • Colluvium/topsoil, artificial fill, which are underlain at depth by terrace deposits were encountered during our investigation. The colluvium/topsoil, artificial fill, and near- surface weathered terrace deposits are typically porous, loose·, and subject to settlement. These soils are considered potentially compressible in their existing state, and have a moderate potential for hydrocollapse or hydrocompression; thus, colluvium/topsoil, artificial fill; and weathered near-surface terrace deposits onsite may settle appreciably under additional fill, foundation, or improvement loadings. Depth of removals are outlined in the conclusions and recommendations section of this report. In general, removals will be on the order of ±1 to ±2 feet across a majority of the site. Groundwater was-not encountered onsite and is generally not anticipated to affect site development, providing that the recommendations contained in this report are incorporated into final design and construction, and that prudent surface and -1 I I I I I I I I I I I I I I ,1 I I I • • • • subsurface drainage practices are incorporated into the construction plans. Perched groundwater conditions along zones of contrasting permeabilities may not be precluded from occurring in the future as a result of site irrigation, poor drainage conditions, or damaged utilities. Should perched groundwater conditions develop, this office could · assess the affected area(s) and provide the appropriate recommendations to mitigate the observed groundwater conditions. Our laboratory test results indicate that soils onsite are generally very low in expansion potential, per the 1997 UBC. Typical samples of the site materials were analyzed for corrosion/soluble sulfate potential. The testing included determination of pH, soluble sulfates, and saturated resistivity. At the time of this report the results were not available. An addendum to this report will be issued when the testing is complete. Field mapping in the site vicinity, noted the presence of numerous paleoliquefaction (ancient) features_ ("sand blows," liquefaction craters, sand filled fissures and injection dikes, sand vents, etc.), which may also exist within the site. Potential liquefaction in such areas (in the future) impacting surface improvements is considered very low, provided that the recommendations presented in this report are incorporated into design and construction of this project. Based on our review, the site is expected to have a low risk to be affected by seismic hazards. The seisrnicity acceleration values provided herein should be considered during the design of the proposed development. The geotechnical design parameters provided herein should be considered during project planning design and construction by the project structural engineer and/or architects. Mr. Ed Hendrix File:e:\wp7\3300\3344a.pge W.O. 3344-A-SC Page Two GeoSoils, lne. I. I The opportunity to be of service is sincerely appreciated. If you should have any questions, please do not hesitate to contact our office. I I I I I I I I I I I I I I I I I Respectfully submitted, GeoSoils, Inc. ~~E C-1fry~1-_ E. yoss Staff Geologist BV/JPF/DWS/jh Distribution: (4) Addressee Mr. Ed Hendrix File:e:\wp7\3300\3344a.pge GeoSoils, lne. W.O. 3344-A-SC Page Three 1· I 1· I I I I ·1 I I I I I I I I I I I TABLE OF CONTENTS SCOPE OF SERVICES .................................................... 1 SITE DESCRIPTION AND PROPOSED DEVELOPMENT .......................... 1 FIELD STUDIES ..................................... ~ .................... 3 REGIONAL GEOLOGY .................................................... 3 EARTH MATERIALS ....................................................... 3 . Colluvium/fopsoil (Not Mapped) ....................................... 3 Terrace Deposits (Map Symbol -Qt) .................................... 5 FAULTING AND REGIONAL SEISMICITY ...................................... 5 Faulting ........................................................... 5 Seismicity ......................................................... 7 Seismic Shaking Parameters .......................................... 8 Seismic Hazards .................................................... a OTHER GEOLOGIC HAZARDS .............................................. 9 GROUNDWATER ......................................................... 9 LIQUEFACTION ......................................................... 1 O LABORATORY TESTING .................................................. 10 Laboratory Standard ................................................ 1 o · Expansion Potential ................................................. 11 Shear Testing ..................................................... -11 Corrosion/Sulfate Testing ........... ·, ~--·· ~ . ; ........ , .................. 11 DISCUSSION AND CONCLUSIONS ......................................... 12 General .......................................................... 12 Earth Materials .................................................... 12 Colluvium/f.opsoil ............................................ 12 Artificial fill ............... ~ . , . . . . . . . . . . . . . . . . . . . . . . . . . . . ..... 12 Terrace Deposits ............................................. 12 Expansion/Corrosion Potential ....................................... 13 Subsurface and Surface Water ....................................... 13 Regional Seismic Activity ................................. : .......... 13 EARTHWORK CONSTRUCTION RECOMMENDATIONS ........................ 13 General .............. ; ........................................... 13 Site Preparation ................................................... 14 Removals (Unsuitable Surficial Materials) ............................... 14 Fill Placement ..................................................... 14 Overexcavation .................................................... 14 ·, GeoSo~ls, fne. 1· ·I I I I ·1 I I I I I I I 1· 1· I I I I RECOMMENDATIONS -FOUNDATIONS ..................................... 15 General ............................................................ 15 Conventional Foundation Design ..................................... 15 Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Expansion Classification -Very Low (E.I. O to 20) ......................... 16 EXTERIOR FLA TWORK ................................................... 17 . CONVENTIONAL. RETAINING WALLS ....................................... 18 General .......................................................... 18 Restrained Walls ............................. · ...................... 18 Cantilevered Walls ................................................. 18 Wall Backfill and Drainage ........................................... 19 Retaining Wall Footing Transitions .................................... 19 Footing Excavation Observation .... · .................................. 20 DEVELOPMENT CRITERIA ................................................ 20 Landscape Maintenance and Planting ................................. 20 Additional Site Improvements ........................................ 20 Trenching ......................................................... 21 Drainage .......................................................... 21 Utility Trench Backfill ............................................... 21 PLAN REVIEW .......................................................... 22 INVESTIGATION LIMITATIONS ............. ; ............................... 22 FIGURES: Figure 1 -Site Location Map .......................................... 2 Figure 2 -Geotechnical _Map .......................................... 4 Figure 3 -California Fault Map·.·,:.=: .. :.: ...... ;, .... , ...... ~ ... _. .• ,. ......... :. 6 ATTACHMENTS: Appendix A -References .................................... Rear of Text Appendix B -Boring Logs ................................... Rear of Text Appendix C -Laboratory Data .............................. · .. Rear of Text Appendix D -General Earthwork and Grading Guidelines .......... Rear of Text Mr. Ed Hendrix File:e:\wp7\3300\3344a.pge GeoSoils, lne. Table of Contents Page ii I I I I I I I I I I I I I I I I I I ·1 PRELIMINARY GEOTECHNICAL EVALUATION 470 CHINQUAPIN AVENUE CARLSBAD, SAN DIEGO C,OUNTY, CALIFORNIA SCOPE OF SERVICES The scope of our services has included the following: · 1. Review of readily available soils and geologic data {Appendix A). 2. Subsurface exploration consisting of the excavation off our exploratory hand auger borings in the area of proposed improvements, for geotechnical logging and sampling {Appendix B). 3. Laboratory testing of representative soil samples collected during our subsurface exploration· program {Appendix C). 4. Appropriate engineering and geologic analysis of data collected and preparation of this report. SITE DESCRIPTION AND PROPOSED DEVELOPMENT The site consists of a roughly rectangular shaped parcel located on the north side of Chinquapin Avenue in Carlshad, San Diego County, California (see Site Location Map, Figure 1). There is an existing two-story single family residence at the south end of the property. The existing site is surrounded by housing developments. Overall, the property is relatively level with a gently sloping gradient to the southwest. According to a USGS 1968 {photo revised 1975) San Luis Rey Quadrangle. map, the subject site is approximately ±50 feet above Mean Sea l,..evel (MSL). It is our understanding that the proposed site development will consist of a lot split and preparing a new pad for the construction of a two-story single-family residence at the north end of the property. Cut and fill grading techniques would be utilized to create design grades for the proposed single-family residential structure with slab-on-grade floors and continuous footings, utilizing wood-frame construction. Building loads are assumed to be typical for this type of relatively light construction. The need for import soils is unknown. GeoSoils, Jne. I I I I I I I I I I I I I I I I I I I l ,. : l},133",9,5; ...... ~~--.;+...--=-,,----¥.i-~r- i --,,. .• 0 2.000 40.00 Scale: Feet i \ \ N w.o. 3'3'44-A-SC SITE LO-CATION MAP Figure 1 I -1 I I I I I· -I I I I I I I I I I I I FIELD STUDIES Field studies conducted by GSI consisted of four exploratory hand auger borings for evaluation of near-surface soil and geologic conditions. Borings were logged by a geologist from our firm who collected representative bulk and undisturbed samples for appropriate laboratory testing. Logs of the borings are presented in Appendix B. The locations of the borings are presented on Geotechnical Map, Figure 2. REGIONAL GEOLOGY The subject property is located within a prominent natural geomorphic province in southwestern California known as the Peninsular Ranges. It is characterized by steep, elongated mountain ranges and valleys thattrend northwesterly. The mountain ranges are underlain by basement rocks consisting of pre-Cretaceous metasedimentary rocks, Jurassic metavolcanic rocks, and Cretaceous plutonic rocks of the southern California batholith. In the San Diego region, deposition occurred during the Cretaceous period and Cenozoic era in the continental margin of a forearc basin. Sediments, derived from Cretaceous-age plutonic rocks and Jurassic-age volcanic rocks, were deposited into the narrow, steep, coastal plain and continental margin of the basin. These rocks have been uplifted, eroded and deeply incised. During early Pleistocene time, a broad coastal plain was developed ·from the deposition of marine terrace deposits. During mid to late Pleistocene time, this plain was uplifted, eroded, and incised. Alluvial deposits have since filled the lower valleys, and young marine sediments are currently being deposited/eroded within coastal and beach areas. EARTH MATERIALS Earth materials encountered on the site consist of colluvium/topsoil, artificial fill, and terrace deposits. · Colluvlum/Topsoll {Not Mapped} Surficial colluvium/topsoil was encountered in all borings excavated onsite. Colluvium/topsoil materials consisted of brown, silty sand. The materials generally were dry and loose with roots and rootlets. The thickness of the colluvium/topsoil is on the order of ± ½ foot. These surficial soils are considered unsuitable for support of additional fill and/or settlement sensitive improvements in-their existing state, owing to their potential for hydrocollapse. Mr. Ed Hendrix 470 Chinquapin Avenue, Carlsbad File:e:\wp7\3300\3344a.pge GeoSoils, lne. W.O. 3344-A-SC July 29, 2002 Page3 I I I I I I I .I I ·1 -I I. I I I I I I I afu Qt ~ --· ----------. -. -. ---. -------·'r --------. ·-~ '. ----~ , I : , I l . · t b I ! f afu \ Qt J , i 1 I ,1.--: • ·• ··--·-·, : • • • • • ,, --, -=" ,1 ~i , . :-·. " B-4 •, .. ·: . " B-~ ·, I • : .. : • ·. ,:> . : -.:i: • .: . •.' PAOPOS:ED 2 CAA AND i • 0 ---·~ ~-; •• .. O 2ND FLOOR F-l.o'\T . '? '1 • • • i · • •• ·• • • •: ~ B 1 . • .. • .. , • " " •, ~ I ,: ~ -~ • I ' " . • .• ~ • • '-A .. !,~ .. _.... • ., .a:, f !Qt';. > : . : . · · · ' : ... • -. ·: !-~ B-3 1 1 1 • 1 I ti a,• •' • I fi;, • .:,ii ! , .. It .. • 'I ,. • f I .. , , • I • ·~ •" ·~~•.,:..·...:.·-"~· .. •--11:---------------l 4 : l 1,_. a. • " .... • .,,,.... I • f •. • . ...... ~ __lL. ;_; •. ,,.. : • • ~ , ~ / /I 6' o·T'"""-------211· a.·~-~--. a• -O'-:?l •. • ,,. // , I r .• I, I "t / f .. . . ' I 9 •1 \ • / I I j • :. '° • • f , I• ., ': • j I ·;· •• ·i L . .l, -;,·'-T 0--71 17' c.:• ' I , •1 / C I • ; • .. . i 1-· ------------ ' J. .. _ _.,. I "' ..... ~ , I 1! • 1, .... I ' . i ' • ' ' • • I j -~ t >: .. EXISTING .SINGLE -------.&.6·~--- I ~ ~ I f i~·~ ': •• ···: :·, FAMILY DEWLLING .. • • • I •. I • .... L. ~. ·( 1 :, -.z::. -:j GARAGE I ,. ·.·,; 2CAR , ; • • • 61 "· '·J .,,.41} ··1 ••• -·~·"' ~ .. •1 ,:· I ••.•• I l II.,, " • , ~ 4, .,. r I 1 , I I • t •• '• •, • : .. • I • I Iii • . '.. . . . .. ~ .. ; .. .. • .. ... I !• ,•. • ,,i "' I ., •• • • " .:• 4 • I I 'Co, , -~ I . " . " I( ~ IQ ... • • " Qt ... . -· .. •" ') . . ; I. '.. •• ; I .. --e: I I • •: t I "' • •~ ' 41,. • f : ~ ! . . " .. • • I I I ~ • t i i:a : • ·~ '( " • 0 ~ • • • -" IJ ,. " I ' • "" • ; I I .. • • I . I . • • . • • • .... I I ,. I ! ! • • •• • • t •• "' ""' I i •• a. • I • : I •• I C • " • .. I ' ! 1 · : .··. ::·: ~ ·J l 1 . .':'. ~-· ~· .\ ._. : -~~ ~ I 1 I I ,, • •" 1 .. • • ! l_ J,_:. __ _:1t_: .. .1-..---·-----' ___ J...---~-:._k.:._.:·..___L. ___ j LEGEND Undocumented, artificial fifl Quaternary Terrace depo~it- Base map provided by client, I . , • LOS ANGELES CO: RIVERSIDE CO • ORANGE CO . SAN DIEGO CO. ...... --. Approximate location of geologic contact GEOTECHNICAL MAP Fi"gure 2: ; Approximate location of expJoratory boring ' W.O. 3344-A-SC_ DATE 7 /02 SCALE. 1":10'. I -I I I I I I I I I I I I I I I I I I Artificial Fill (Map Symbol Afi Artificial fill was encountered in Boring 8-4 excavated onsite. The artificial fill materials consisted of brown, silty sand. These soils generally were dry and loose with roots and rootlets. The thickness of the colluvium is on the order of ± 1 foot. This soil is considered unsuitable for support of additional fill and/or settlement sensitive improvements in their existing state, owing to their potential for hydrocollapse. Terrace Deposits (Map Symbol -Qt) The Quaternary-age terrace deposits underlie the entire site at depth. As encountered, the terrace deposits generally consist of reddish brown to orange brown, silty sand, and are medium dense to dense with depth. As a result of the relatively loose and weathered condition of the upper±½ foot, these weathered sediments should be removed, moisture ·conditioned, and recompacted and/or processed in place, should settlement-sensitive improvements be proposed. FAUL TING AND REGIONAL SEISMICITV Faulting The site is situated in an area of active as well as potentially-active faults. Our review indicates that there are no known active faults crossing the site within the areas proposed for development (Tan and Kennedy, 1996), and the site is not within an Earthquake Fault Zone. There are a number offaults in the southern California area that are considered active and would have an effect on the site in the form of ground shaking, should they be the source of an earthquake. These include-but are -not limited to-the San Andreas fault, the San Jacinto fault, the Elsinore fault, the Coronado Bank fault zone, and the Newport-Inglewood/Rose Canyon fault zone. The location of these and other major faults relative to the site are indicated on Figure 3. The possibility of ground acceleration or shaking at the site may be considered as approximately similar to the southern California region as a whole. The following table lists the major faults and fault zones in southern California that could have a significant effect on the site should they experience significant activity. Mr. Ed Hendrix 470 Chinquapin Avenue, Carlsbad File:e:\wp7\3300\3344a.pge GeoSoils, lne. W.O. 3344-A-SC July 29, 2002 Pages I· I I I I- I I I I .I I I ·1 ·I I I ! I I I \ I SITE L0CATI0~_(:t --L;tit~d_e_ -33.1485 N w Lo.ngitude -117.3397 HENDRIX . 0 CALIFORNIA .FAULT w .0. 3344-A-SC 50 100 SCALE (Miles) Figure 3 I I I I I I I I I I I I I I I I I I I - ABBREVIATED APPROXIMATE DISTANCE .. FAULTNAME· . MILES (KM) Coronado Bank-Agua Blanca 21 (33} Elsinore 25 (40} La Nacion 24 (39) . Newport-Inglewood-Offshore 8 (12} Rose Canyon · 4 (7) -San Diego Trough-Bahia Sol 30 (48) . Seismicity The acceleration-attenuation relations of Joyner and Boore (1982}, Campbell and Bozorgnia (1994), and Sadigh and others (1989} have been incorporated into EQFAULT (Blake, 1997). For this study, peak horizontal ground accelerations anticipated at the site were determined based on the random mean plus 1 -sigma attenuation curves developed by Joyner and Boore (1982), Campbell and Borzorgnia (1994), and Sadigh and others (1989}. These acceleration-attenuation relations have been incorporated in EQFAULT, a computer program by Thomas F. Blake (1997), which performs deterministic seismic hazard analyses using up to 150 digitized California faults as earthquake sources. ihe program estimates the closest distance between each fault and a user-specified file. If a fault is found to be within a user-selected radius, the program estimates peak horizontal ground acceleration that may occur at the site from the upper bound ("maximum credible") and 11maximum probable" earthquakes on that fault. Site acceleration (g) is computed by any of the 14 user-selected acceleration-attenuation relations that are contained ·in EQFAULT. Based on the abov~. peak horizontal ground accelerations from an upper bound event may be on the order of 0.65 g to 0.79 g, and a "maximum probable" event may be on the order of 0.32 g to 0.46 g, assuming an earthquake, on the Rose Canyon fault zone, located approximately 4.6 miles from the subject site. Historical site seismicity was evaluated utilizing the computer program EQSEARCH (Blake, 1989}. This program performs a search of historical earthquake records, for magnitude 5.0 to magnitude 9.0 within a specified radius (e.g., 100 miles), between the years 1800 to 2002. Based on the selected acceleration-attenuation relation, a peak horizontal ground acceleration is estimated, which may have affected the site during the specific seismic event listed. In addition, site specific probability of exceeding various peak horizontal ground accelerations and seismic recurrence curves are also estimated/generated from the historical data. The maximum horizontal peak ground acceleration experienced by the site during the period of 1800 to June, 2002 was estimated to be about 0.8 g corresponding to Mr. Ed Hendrix 470 Chinquapin Avenue, Carlsbad File:e:\wp7\3300\3344a.pge GeoSoils, Ine. , ;.· ' W.O. 3344-A-SC July 29, 2002 Page7 I I I I I I I I I I I I I I I I -I I I I an earthquake of about M 6.5 approximately 11 miles away, that occurred on November 22, 1800. A probabilistic seismic hazards analysis was also performed using FRISKSP (Blake, 1997), which models earthquake sources as lines and evaluates the site specific probabilities. Based on a review of these data and considering the relative seismic activity of the southern California region, a horizontal peak ground acceleration in the range of 0.28 g to 0.33 g was obtained. These values were considered as they correspond to a 1 O percent probability of exceedance in 50-years (or a 475 year return period). Seismic Shaking Parameters Based on the site conditions, Chapter 16 of the Uniform Building Code (International Conference of Building Officials, 1997),. the following seismic parameters are provided: Seismic zone (per Figure 16-2*} 4 Seismic Zone Factor (per Table 16-1*} 0.40 Soil Profile Type (per Table 16-J*) So Seismic Coefficient c. (per Table 16-Q*) 0.44 Na Seismic Coefficient Cv (per Table 16-R*) 0.64 NV Near Source Factor N. (per Table 16-S*) 1.0 Near Source Factor Nv (per Table 16-T*) 1.15 Seismic Source Type (per Table 16-U*) B Distance to Seismic Source 4.1 mi (6.5 km} Upper Bound Earthquake Mw6.9 * Figure and table references from Chapter f6 of the Uniform Building Code (1997}. Seismic Hazards . The following list includes other seismic related hazards that have been considered during our evaluation of the site. The hazards listed are considered negligible and/or completely mitigated as a result of site location, soil characteristics and typical site development procedures: Mr. Ed Hendrix 470 Chinquapin Avenue, Carlsbad File:e:\wp7\3300\3344a.pge GeoSoils, lne. W.O. 3344-A-SC July 29, 2002 Pages I I I I I 1. I I I I I I I I I I I I I • Liquefaction • Dynamic Settlement • Surface Fault Rupture • Ground Lurching or Shallow Ground Rupture • Tsunami It is important to keep in perspective that in the event of a maximum probable or credible earthquake occurring on any of the nearby major faults, strong ground shaking would occur in the subject site's general area. Potential damage to any structure(s} would likely be greatest from the vibrations and impelling force caused by th~ inertia of a structure's mass, than from those induced by the hazards considered above. This potential would be no greater than that for other existing structures and improvements in the immediate vicinity. OTHER GEOLOGIC HAZARDS Mass wasting refers to the various processes by which earth materials are moved down slope in response to the force of gravity. Examples of these processes include slope creep, surficial failures, and deep-seated landslides. Creep is the slowest form of mass wasting and generally involves the outer 5 to 1 o feet of a slope surface. During heavy rains, such as those in 1'969, 1978, 1980, 1989, 1993, and 1998 creep-affected materials may become saturated, resulting in a more rapid form of downslope movement {i.e., landslides and/or surficial failures}. The site topography is very flat lying, no such slopes are proposed, and indications of deep seated landsliding on the site were not observed during our site reconnaissance. Therefore, the potential for seismically induced landsliding is considered nil. GROUNDWATER Subsurface water was not encountered within the property during field work performed in preparation of this report. Subsurface water is not anticipated to adversely affect site development, provided thatthe recommendations contained in this report are incorporated into final design and construction. These observations reflect site conditions at the time of our investigation and do not preclude future changes in local groundwater conditions from excessive irrigation, precipitation, or that were not obvious, at the time of our investigation. Seeps, springs, or other indications of a high groundwater level were not noted on the subject property during the time of our field investigation. However, seepage may occur locally (as a result of heavy precipitation or irrigation} in areas where fill soils overlie terrace deposits. Depth to the regional water table is anticipated to be greater than 50 feet below existing grade. Mr. Ed Hendrix 470 Chinquapin Avenue, Carlsbad File:e:\wp7\3300\3344a.pge GeoSoils, lne. W.O. 3344-A-SC July 29, 2002 Page9 I I I I I I I I I I I I I I I I I I I LIQUEFACTION Liquefaction describes a phenomenon in which cyclic stresses, produced by earthquake induced grou·nd motion, create excess pore pressures in relatively cohesionless soils. These soils may thereby acquire a high degree of mobility, which can lead to lateral movement sliding, consolidation and settlement of loose sediments, sand boils, and other . · damaging deformations. This phenomenon occurs only below the water table, but after liquefaction has developed, it can propagate upward into overlying, non-saturated soil, as . excess pore water dissipates. Liquefaction susceptibility is related to numerous factors and the following conditions must exist for liquefaction to occur: 1) sediments must be relatively young in age and not have developed large amount of cementation; 2) sediments must consist mainly of medium to fine grained relatively c;:ohesionless sands; 3) the sediments must have low relative density; 4) free groundwater must be present in the sediment; and 5) the site must experience seismic event of a sufficient duration and large enough magnitude, to induce straining of soil particles. At the subject site, three of the five conditions which are necessary for liquefaction to occur exist, and the site may or may not experience the other two. One of the primary factors controlling the potential for liquefaction is depth to groundwater. Liquefaction susceptibility generally decreases as the groundwater depth increases for two reasons: 1) the deeper the water table, the greater normal effective stress acting on saturated sediments at any given depth and liquefaction susceptibility decreases with increased normal effective stress; and 2) · age, cementation, and relative density of sediments generally increase with depth. Thus, as the depth to the water table increases, and as the saturated sediments become older, more cemented, have higher relative density, and confining normal stresses increase, the less likely they are to liquefy during a seismic event. Typically, liquefaction has a relatively low potential where groundwater is greater than 30 feet deep, and virtually unknown below 60 feet. Mitigation of liquefaction potential is also accomplished by the incorporation of our grading guidelines foundation . design parameters into project planning design and construction. LABORATORY TESTING Laboratory tests were performed on a representative sample of representative site earth materials in order to evaluate their physical characteristics. Test procedures used and results obtained are pres~nted below. · Laboratory Standard The maximum density and optimum rn9i§ture content was determined for the major soil type encountered in the borings. The laboratory standard used was ASTM D-1557. The moisture-density relationship obtained for this soil is shown in the following table: Mr. Ed Hendrix · 470 Chinquapin Avenue, Carlsbad . File:e:\wp7\3300\3344a.pge GeoSoils, lne. W.O. 3344-A-SC July 29, 2002 Page 10 I I I I I I- I I I I I I I I I I I I I MAXIMUM DENSITY OPTIMUM MOISTURE LOCATION SOIL TYPE (PCF) CONTENT(%) 8-1 @0-4' Silty Sand, Brown 133.5 9.5 Expansion Potential Expansion testing was performed on representative samples of site soil in accordance with UBC Standard 18-2 {UBC, 1997). The results of expansion testing are presented in the following table. Shear Testing Shear testing was performed on a representative, "remolded" sample of site soil in general accordance with ASTM test method D-3080 in a Direct Shear Machine of the strain control type.· The shear test results are presented as in Plate C-1 in Appendix C, and as follows: -' : : .... _., ."' ' :.,·:<:::.: i·.-i,<(:.: .. ' .. p~~MA~4..;.': :: :.':_: ' ·.-_:-. '', .·.: ,', :··. RESIDUAL' ~ ::·::_./i ·sAM-~(e:: ·, ; · > · ... -,-.; =-: ... .-:··: :· ·:.-: : .. ,.:1-., ...... ·,· .. ·: · :i. . .-.= .-.-_._.. -·· . . ... :-_:'.' LOCATiON ·:·, s.;·:·.:c61-fEs'1otf:' . ..: '.:=:.·.FR_ICTIO~: < ·_. .... COH,ESION '-: .. .'_:_·_·. FRICTION ' ,:i:'r~:,i·r::_;-\:::::;-.·: __ :_ {.:,:.::/;::· ... }PS,f(\.;::\·_\::·. ·.::Jo:~~~~S)': '. ::_·: '_·.·(PSF)'.-' ,: ·:-::·--.,~:~~~~S). 8-1@0-4' (remolded) 177 Corrosion/Sulfate Testing 33 165 31 Typical samples of the site materials were analyzed for corrosion/soluble sulfate potential. The testing included determination of pH, soluble sulfates, and saturated resistivity. At the time of this report the results were not available. An addendum to this report will be issued when the testing is complete. Mr. Ed Hendrix 470 Chinquapin Avenue, Carlsbad File:e:\wp7\3300\3~44a.pge GeoSoils, lne. W.O. 3344-A-SC July 29, 2002 Page 11 I· I I I I I I I I I I I I I I I I I I DISCUSSION AND CONCLUSIONS General Based on our field exploration, laboratory testing, and geotechnical engineering analysis, it is our opinion that the subject site i's suitable for the proposed development from a geotechnical engineering and geologic viewpoint, provided that the recommendations presented in the following sections are incorporated into the design and construction phases of site development. The primary geotechnical concerns with respect to the proposed development and improvements are: • Earth materials characteristics and depth to competent bearing material. • Expansion and corrosion potential of site soils. • Subsurface water and potential for perched water. • Regional seismic activity . . The recommendations presented herein consider these as well as other aspects of the site. In the event that any significant changes are made to proposed site development, the conclusions and recommendations contained in this report shall not be considered valid unless the changes are reviewed and the recommendations of this report verified or modified in writing by this office. Foundation design parameters are considered preliminary until the foundation design, layout, and structural loads are provided to this office for review. Earth. Materials Colluvium/Topsoil Colluvium/topsoil materials are generally dry and loose, susceptible to hydrocollapse and do not meet the current industry minimum standard of 90 percent (or greater) relative compaction. Recommendations for the treatment of colluvium/topsoil are presented in the earthwork section of this report. Artificial fill Artificial fill materials are generally dry and loose, susceptible to hydrocompression and do not meet the current industry minimum standard of 90 percent (or greater) relative compaction. Recommendations for the treatment of artificial fill are presented in the earthwork section of this report. Terrace Deposits Terrace deposits will be encountered ~wing site earthwork. The upper±½ foot of the terrace deposits are weathered and should be removed and recompacted. Below the -weathered zone, the materials are considered comp~tent to support settlement-sensitive structures in their existing state. Mr. Ed Hendrix 470 Chinquapin Avenue, Carlsbad File:e:\wp7\3300\3344a.pge Geo.Soils, lne. . . W.O. 3344-A-SC July 29, 2002 Page 12 I I I I I I I -I I I I I I I I I I I I Expansion/Corrosion Potential Our laboratory test results indicate that soils with a very low expansion potential (expansion index [E.1.] range Oto 20). This should be considered during project design. Foundation design and construction recommendations are provided herein for very low expansion potential classifications. Subsurface and Surface Water Subsurface and surface waters, as discussed previously, are not anticipated to affect site development, provided that the recommendations contained in this report are incorporated into final design and construction· and that prudent surface and subsurface drainage practices are. incorporated into the construction plans. Perched groundwater conditions along fill/formational contacts and along zones of contrasting permeabilities may not be precluded from occurring in the future during grading, or as a result of site irrigation, poor drainage conditions, or damaged utilities. Should perched groundwater conditions develop, this office could assess the affected area(s) and provide the appropriate recommendations to mitigate the observed groundwater conditions. The groundwater conditions observed and opinions generated were those at the time of our investigation. Conditions may change with the introduction of irrigation, rainfall, or other factors that were not obvious at the time of our investigation. Regional Seismic Activity the seismic acceleration values provided herein should be considered during the design of the proposed development. EARTHWORK CONSTRUCTION RECOMMENDATIONS General All grading should conform to the guidelines presented in Appendix Chapter A33 of the Uniform Building Code, the requirements of the City of Carlsbad, and the Grading Guidelines presented in Appendix D, except where specifically superseded in the text of this report. Prior to grading, a GSI representative should be present at the preconstruction meeting to provide additional grading guidelines, if needed, and review the earthwork schedule. During earthwork construction all site preparation and the general grading procedures of the contractor should be observed and the fill selectively tested by a representative(s) of GSI. If unusual or unexpected conditions are ·exposed in the field, they should be reviewed by this office and if warranted, modified and/or additional recommendations will be offered. All applicable requirements of local and national construction and general industry safety Mr. Ed Hendrix 470 Chinquapin Avenue, Carlsbad File:e:\wp7\3300\3344a.pge · GeoSoils, Ine. W.O. 3344-A-SC July 29, 2002 Page 13 I ·I I I I I I I I I I I I I I I I I I orders; the Occupational Safety and Health Act, and the Construction Safety Act should be met. Site Preparation Debris, vegetation and other deleterious material should be removed from the building area prior to the start of grading. Sloping areas to receive fill should be properly benched in accordance with current industry standards of practice and guidelines specified in the Uniform Building Code. Removals (Unsuitable Surficial Materials) As a result of the relatively loose/soft condition of colluvium/topsoil, artificial fill, and weathered terrace deposits, these materials should be removed and recompacted in areas proposed for settlement sensitive structures, or areas to receive compacted fill. Atthis time, removal depths on the order of ± 1 to ±2 feet should be anticipated; however, locally deeper removals may be necessary. Removals should be completed below a 1 :1 projection down and away from the outside bottom edge of any settlement sensitive structure and/or limits of proposed fill. Once removals are completed, the exposed bottom should be reprocessed and compacted. Fill Placement Subsequentto-ground preparation, onsite soils may be placed in thin (±6-inch) lifts, cleaned of vegetation and debris, brought to a least optimum moisture content, and compacted to achieve a minimum relative compaction of 90 percent. If soil importation is planned, a sample of the soil import should be evaluated by this office prior to importing, in order to assure compatibility with the onsite site soils and the recommendations presented in this report. Import soils (if any) for a fill cap should be very low expansive (E.I. less than 20). · The use· of subdrains at the bottom of the fill cap may be necessary, and subsequently recommended based on compatibility with onsite soils. Overexcavation In order to provide for the uniform support of the planned structure, a minimum 3-foot thick fill blanket is recommended for the graded pad. Any cut portion of the pad for the residence should be overexcavated a minimum 3 feet below finish pad grade. Areas with planned fills less than 3 feet should be overexcavated in order to provide the minimum fill thickness. Fill thickness should not exceed a ratio of 3: 1 (maximum to minimum) across the building areas. This overexcavation should be performed 5 feet outside the building footprint. Mr. Ed Hendrix 470 Chinquapin Avenue, Carlsbad File:e:\wp7\3300\3344a.pge GeoSoils,. Ine. W.O. 3344-A-SC July 29, 2002 Page 14 I I I I I I I I I ·1 I I I ·I I I I I I RECOMMENDATIONS-FOUNDATIONS General Recommendations for conventional foundation system are reiterated and/or provided in the following sections. Conventional foundations may be utilized for soils with Expansion Indices (E.I.) of less than 20 (E.I. very low classification). The foundation system may be used to support the proposed structure, provided they are fouAded in competent bearing material. The proposed foundation systems should be designed and constructed in accordance with the guidelines contained in the Uniform Builc;ling Code, and in accordance with the recommendations of the project structural engineer. Conventional Foundation Design 1. 2. 3. 4. 5. Conventional spread and continuous footings may be used to support the proposed residential structure provided they ~re founded entirely in properly compacted fill or other competent bedrock. Analyses indicate that an allowable bearing value of 1,500 pounds per square foot may be used for design of footings which maintain a minimum width of 12 inches (continuous) and 24 inches square (isolated), and a minimum depth of at least 12 inches into the properly compacted fill or bedrock. The bearing value may be increased by one--third for seismic or other temporary loads. This value may be increased by 200 pounds per square foot for each additional 12 inches in depth, to a maximum of 2,500 pounds per square foot. No increase in bearing value for footing width is recommended. For lateral sliding resistance, a 0.35 coefficient of friction may be utilized for a concrete to soil contact when multiplied by the dead load. Passive earth pressure may be computed as an equivalent fluid having a density of 250 pounds per cubic foot with a maximum earth pressure of 2,500 pounds per square foot. When combining passive pressure and frictional resistance, the passive pressure component should be reduced by one-third. 6. All footings should maintain a minimum 7-foot horizontal distance between the base of the footing and any adjacent descending slope, and minimally comply with the guidelines depicted on Figure No. 18-1-1 of the UBC (1997). Construction The following foundation construction recommendations are presented as a minimum criteria from a soils engineering viewpoint. The onsite soils expansion potentials are Mr. Ed Hendrix 470 Chinquapin Avenue, Carlsbad File:e:\wp7\3300\3344a.pge GeoSoils, Jne. W.O. 3344-A-SC July 29, 2002 Page 15 I • I I I I I 1· I I I I I I I I I I I I I I 1· generally in the very low range (Expansion Index [E.1.] Oto 20). Recommendations by the project's design-structural engineer or architect, which may exceed the soils engineer's recommendations, should take precedence over the following minimum requirements. -Expansion Classification -Very Low (E.I. o to 20} 1. -Continuous exterior footings should be founded at minimum depths of 12 and 18 inches below the lowest adjacent ground surface, for one-or two-story floor loads, respectively, and in accordance with the minimum requirements of the latest edition of the Uniform Building Code. The project structural engineer should review and approve these recommendations. Continuous interior footings may be founded at a minimum depth of 12 inches below the lowest adjacent ground surface. Footings should be a minimum of 12 inches wide, or as determined by the structural engineer. 2. .All footings should have one No. 4 reinforcing bar placed at the top and one No. 4 reinforcing bar-placed at ttie bottom of the footing. Isolated interior or exterior piers and columns should be founded at a minimum depth of 18 inches below the lowest _adjacent ground surface, and in accordance with the structural engineers recommendations. 3. A grade beam, reinforced as above, and at least 12 inches square, should be provided across the garage entrances. The base of the reinforced grade beam should be at the same elevation as the adjoining footings. 4. Concrete slabs in residential and garage areas should be underlain with a vapor barrier consisting of a minimum of 6-mil, polyvinyl-chloride membrane with all laps sealed. This membrane should be covered with a minimum of 2 inches of sand to _ aid in uniform curing of the concrete (2 inches of sand total). · 5. For pads with very low expansion indices (E.I. Oto 20), concrete slabs, including garage slabs, should be reinforced with No. 3 reinforcement bars placed on 18-inch centers, in two horizontally perpendicular directions (i.e., long axis and short axis). All slab reinforcement should be supported to ensure proper mid-slab height positioning during placement of the concrete. "Hooking" of reinforcement is not an acceptable method of positioning. 6. Garage slabs should be poured separately from the residence footings and be quartered with expansion joints or saw cuts. A positive separation from the footings should be maintained with expansion joint material to permit relative movement. 7. The residential and garage slabs should have a minimum thickness of 4 inches, and the slab subgrade should be free of loose and uncompacted material prior to placing . concrete. The design engineer should determine the actual thickness of concrete slabs based upon proposed loading and use. Mr. Ed Hendrix . 470 Chinquapin Avenue, Carlsbad File:e:\wp7\3300\3344a.pge GeoSoils, lne. W.O. 3344-A-SC July 29, 2002 Page 16 I I I I I 1· I I 1· ·I I I I I I I I I I 8. Presaturation is not necessary for these soil conditions; however, the moisture content of the subgrade soils should be equal to or greater than optimum moisture to a depth of 12 inches below the adjacent ground grade in the slab areas, and verified by this office within 72 hours of the vapor barrier placement. ·9. As an· alternative, an engineered post-tension foundation system may be used. Recommendations for post-tensioned slabs can be provided on request. 10. Soils generated from footing excavations to be used onsite should be compacted to a minimum relative compaction 90 percent of the laboratory standard, whether it is to be placed inside the foundation perimeter or in the yard/right-of-way areas. This material must not alter positive drainage patterns that direct drainage away from the structural areas and toward the s~reet. 1 t. Design of proposed pools and other appurtenant structures should be reviewed by GSI. EXTERIOR FLATWORK Exterior driveways, walkways, sidewalks, or patios, using concrete slab on grade construction should be designed and constructed in accordance with the following criteria: 1. Structural and driveway slabs should be a minimum 4 inches in thickness; all other exterior slabs maybe a nominal 4 inches in thickness. A thickened edge (minimum of 12 inches) should be constructed for all flatwork adjacent to landscape areas. 2. Slab subgrade (i.e., existing fill materials) should be compacted to a minimum 90 percent relative compaction and moisture conditioned to at or above the soils optimum moisture content. This should be verified by this office at least 72 hours prior to pouring concrete. The use of Class 2, Class 3, or decomposed granite (i.e., . DG) as a base for the concrete slab in non-vehicle traffic areas is not required. 3. The use of transverse and longitudinal control joints should be considered to help control slab cracking due to concrete shrinkage or expansion. Two of the best ways to control this movement is: 1) add a sufficient amount of reinforcing steel, increasing tensile strength ofthe slab; and/or 2) provide an adequate amount of control and/or expansion joints to accommodate anticipated concrete shrinkage and expansion. We would suggest that the maximum control joint spacing be placed on 5-to 8-foot centers, or the smallest dimension of the slab, whichever is least. 4. No traffic should be allowed upon the newly poured concrete slabs until they have been properly cured to within 75 percent of design strength. Mr. Ed Hendrix 470 Chinquapin Avenue, Carlsbac;I File:e:\wp7\3300\3344a.pge Ge-,Soils, lne. W.O. 3344-A-SC July 29, 2002 Page 17 ;J I I I I I I I- I I I I I I I I I I I I 5. Positive site drainage should be maintained at all times. Water should not be allowed to pond or seep into the ground. If planters or landscaping are adjacent to paved areas, measures should be taken to minimize the potential for water to enter the pavement section. This may be accomplished using thickened PCC pavement edges and _concrete cut off barriers or deepened curbs, in addition to eliminating granular base materials (i.e., Class 2, 3, D.G. etc.) underlying the slab. 6. In areas directly adjacent to a continuous source of moisture (i.e., irrigation, planters, etc.), all joints should be sealed with flexible mastic. 7. Concrete compression strength should be a minimum of 2,500 psi. CONVENTIONAL RETAINING WALLS General The design parameters provided below assume that very low expansive soils (such as Class 2 permeable filter material or Class 3 aggregate base) are used to backfill any retaining walls. If high to very highly expansive soils are used to backfill the proposed walls, increased active and at-rest earth pressures will need to be utilized for retaining wall design, and may be provided upon request. Building walls, below grade, should be water-proofed or damp-proofed, depending on the degree of moisture protection desired. The foundation system for the proposed retaining walls should be designed in accordance with the recommendations presented in the preceding sections of this report, as appropriate. Footings should be embedded a minimum of 18 inches below adjacent grade (excluding landscape layer, 6 inches). There should be no increase in bearing for footing width. Restrained Walls Any retaining walls that will be restrained prior to placing and compacting backfill material or that have re-entrant or male corners, should be designed for an at-rest equivalent fluid pressure (EFP) of 65 pounds per cubic foot (pcf), plus any applicable surcharge loading. For areas of male or re-entrant corners, the restrained wall design should extend a minimum distance of twice the height of the wall laterally from the corner. Cantilevered Walls The recommendations presented below are for cantilevered retaining walls up to 1 O feet high. Active earth pressure may be used for retaining wall design, provided the top of the wall is not restrained from minor deflections. An equivalent fluid pressure approach may be used to compute the horizontal pressure against the wall. Appropriate fluid unit weights are given below for specific slope gradient~ qfthe retained material. These do not include other superimposed loading conditions such as traffic, structures, hydrostatic pressures, seismic events or adverse geologic conditions. When wall configurations are finalized, the appropriate loading conditions for superimposed loads can be provided upon request. Mr. Ed Hendrix 470 Chinquapin Avenue, Carlsbad · File:e:\wp7\3300\3344a.pge GeoSoils, l ne. W.O. 3344-A-SC July 29, 2002 Page 18 I I I· I I· I· I I I I I I I· I I I I I I SURFACE SLOPE OF EQUIVALENT SELECT RETAINED MATERIAL FLUID WEIGHT MATERIAL HORIZONTAL TO VERTICAL P.C.F. (Native soil) P.C.F. Level 42 35 2to 1 60 45 The equivalent fluid density should be increased to 65 pounds per cubic foot for level backfill at the angle point of the wall (corner or male re-entrant) and extended a minimum lateral -distance of 2H (two times the wall height) on either side of the corner. Wall Backfili and Drainage The above criteria assumes that very low· expansive soils are used as backfill, and that hydrostatic pressures are not allowed to build up behind the wall. Positive drainage must be provided behind all retaining walls in the form of perforated pipe placed within gravel wrapped in geofabric and outlets. A backdrain system is considered necessary for retaining walls that are 2 feet or greater in height. Backdrains should consist of a 4-inch diameter perforated PVC or ABS pipe encased in either Class 2 permeable filter material or 1/2-to ¾-inch gravel wrapped in approved filter fabric (Mirafi 140 or equivalent). The filter material should extend a minimum of 1 horizontal foot behind the base of the walls and upward at least 1 foot. Outlets should consist of a 4-inch diameter solid PVC or ABS pipe spaced no more greater than ± 100 feet apart. The use of weep holes in walls higher than · 2 feet should not be considered. The surface of the backfill should be sealed by pavement or the top 18 inches compacted with relatively impermeable soil. Proper surface drainage should also be provided. Consideration should be given to applying a water-proof membrane to all retaining structures. The use of a waterstop should be considered for all concrete and masonry joints. Retaining Wall Footing Transitions Site walls are anticipated to be founded on footings designed in accordance with the recommendations in this report. Wall footings may transition from competent terrace deposits to fill. If this condition is present the civil designer may specify either: a) If transitions from terrace to fill transect the wall footing alignment at an angle of less than 45 degrees (plan view), then the designer should perform a minimum 2-foot overexcavation for a distance of two times the height of the wall and increase overexcavation until such transition is between 45 and 90 degrees to the wall alignment. Mr. Ed Hendrix W. 0. 3344-A-SC July 29, 2002 Page 19 470 Chinquapin Avenue, Carlsbad File:e:\wp7\3300\3344a.pge GeoSoils, Ine. I I I I I I I I I I I I I I I I I I I b) Increase of the amount of reinforcing steel ·and wall detailing (i.e., expansion joints or crack control joints) s1,Jch that an angular distortion of 1/360 for a distance of 2H (where H =wall height in feet) on either side of the transition may be accommodated. Expansion joints should be sealed with a flexible, non-shrink grout. c) Embed the footings entirely into a homogeneous fill. Footing Excavation Observation All footing excavations for walls and appurtenant structures should be observed by the geotechnical consultant to evaluate the anticipated near surface conditions prior to the placement of steel or concrete. Based on the conditions encountered during the observations of the footing excavation, supplemental recommendations may be offered, as · appropriate. DEVELOPMENT CRITERIA Landscape Maintenance and Planting Water has been shown to weaken the inherent strength of soil and slope stability is significantly reduced by overly wet conditions. Positive surface drainage away from graded slopes should be maintained and onlythe amount of irrigation necessary to sustain plant life should be provided for planted slopes. Overwatering should be avoided. Graded slopes constructed within and utilizing onsite materials would be erosive. Eroded debris may· be minimized and surficial slope stability enhanced by establishing and maintaining a suitable vegetation cover soon after construction. Plants selected for landscaping should be light weight, deep rooted types which require little water and are capable of surviving the prevailing climate. Compaction to the face offill slopes would tend to minimize short term erosion until vegetation is established. In order to minimize erosion on a slope face, an erosion control fabric (i.e., jute matting) may be considered. From a geotechnical standpoint leaching is not recommended for establishing landscaping. · If the surface soils area processed for the purpose of adding amendments they should be recompacted to 90 percent relative compaction. Additional Site Improvements Recommendations for additional grading, exterior concrete flatwork design and construction, including driveways, can be provided upon request. If in the future, any additional improvements are planned for the site, recommendations concerning the geological or geotechnical aspects of design and con~truction of said improvements could be provided upon. request. · " · Mr. Ed Hendrix 470 Chinquapin Avenue, Carlsbad File:e:\wp7\3300\3344a.pge GeoSoils, Ine. W.O. 3344-A-SC July 29, 2002 Page20 I I -I I. I I I I I I I I I I I I I- I I Trenching All footing trench excavations for structures and walls should be observed and approved by a representative of this office prior to placing reinforcement. Footing trench spoil and any excess soils generated ·from utility trench excavations should be compacted to a minimum relative compaction of 90 percent if not removed from the site. All excavations should be observed by one of our representatives and conform to CAL-OSHA and local safety codes. GSI does not consult in the area of safety engineers.-· In addition, the potential for encountering hard spots during footing and utility trench excavations should be anticipated. If these concretions are encountered within the proposed footing trench, they should be removed, which could produce larger excavated areas within the footing or utility trenches. Drainage Positive site drainage should be maintained at all times. Drainage should not flow uncontrolled down any descending slope. Water should be directed away from foundations and not allowed to pond and/or seep into the ground. Pad drainage should be directed toward the street or other approved· area. Roof gutters and down spouts should be considered to control roof drainage. Down spouts should outlet a minimum of 5 feet from the proposed structure or into a subsurface drainage system. We would recommend that any proposed open bottom planters adjacent to proposed structures be eliminated for a minimum distance of 1 O feet. As an alternative, closed bottom type planters could be utilized. An outlet placed in the bottom of the planter, could be installed to direct drainage ·away from structures or any exterior concrete flatwork. Utility Trench Backfill 1, All utility trench backfill in structural areas, slopes, and beneath hardscape features should be brought to near optimum-moisture content and then compacted to obtain a minimum relative compaction of 90 percent of the laboratory standard. Flooding/jetting is not recommended for the site soil materials. As an alternative, imported sandy material with a sand equivalence (S.E.) of 30 or greater, may be flooded/jetted 1n shallow (±12 inches or less) under-slab interior trenches, only. 2, Sand backfill, unless trench excavation material, should not be allowed in exterior trenches adjacent to and within an area extending below a 1 : 1 plane projected from the outside bottom edge of the footing. 3. All trench excavations should minimally conform to CAL-OSHA and local safety codes. Mr. Ed Hendrix 470 Chinquapin Avenue, Carlsbad File:e:\wp7\3300\3344a.pge · GeoSoils, Ine. W.O. 3344-A-SC July 29, 2002 Page 21 I I I I I I I I I I I I I I I I I I I I 4. · Soils generated from utility trench excavations to be used onsite should be compacted to 90 percent minimum relative compaction. This material must not alter · positive drainage patterns that direct drainage away from the structural area and towards the street. PLAN REVIEW Final project plans should be reviewed by this office prior to construction, so that construction is in accordance with this report. Based on our review, supplemental recommendations and/or further geotechnical studies may be warranted. · INVESTIGATION LIMITATIONS Inasmuch as our: study is based upon the site materials observed, selective laboratory testing and engineering analysis, the conclusion and recommendations are professional opinions. These opinions have been derived in accordance with current standards of practice, and no warranty is expressed or implied. Standards of practice are subject to change with time. These opinions have been derived in accordance with current standards of practice, and no warranty is expressed or implied. Standards of practice are subjectto change with time. GSI assumes no responsibility or liability for work or testing performed by others, for our scope- of-work was expressly limited to the evaluation of the sediments/soils underlying the proposed residence. In addition, this report may be subject to review by the controlling authorities. Mr. Ed Hendrix 470 Chinquapin Avenue, Carlsbad File:e:\wp7\3300\3344a.pge GeoSoils, lne. W.O. 3344-A-SC July 29, 2002 Page 22 ~ --. .,. . ,._, '', ~-~ :,- ;;,:1· 't. ·, '' t',.' -·. ' . .",,,1 .. ,··:' ''. . 1.., ..,, • 1: -~ .. ._ '~· :·: . ,. I ..,. ~' • -_,, J .. _ -~. '.--: , ~ . ,:. \,,'. ',, ',, ,,, .-. ,: :,, - ' ~. -,' .. ,: ,; ... · ~ •,• : I ' '.•', ,, . . , ,.. ~ ',' . •. .,.,, .. ~-',-t,\ i' ... :·.~/>/: i'' __ ., .... , _'-t ', ,•.,.,,;· ···'· . ,, ,., .. ~· --~~· ', ' ·_ .. ,, ' ~ -~~\, . 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' I': ' ', r, , ... 1.',,- ·. . ' ' ,, ~ :, .... ,· .. :· I _, -' ., .. ,_ , '<~ ,• ·, , '.,_,·,.,·-_· ·,;. --:., ... . : '· . ,. ··-_.,'.· ,.·:·' _,.,_;.·,, • ? ._~,.. -; ... , ' ',, 't, .•!_' --.-.:· ·, . '' ~ ~' ·' ',; ~,._ . ' .. , ; ,.,_ ... :-.' '.-·" ,•., '1:,. ~-,·, .·.-·-'. ; __ . <:-; ·_ '. ,.~ - :· .~ •' • ,f ,. ,-.. --.. ,. . ,,- ''' .. ,,··, .,, ~< : ' . :" .~· ' .... ,. ·, / J ...... ~' ' ·. ~-r' ·., -,;- '•' ,, -•1., .'. '• ' ' '1 '.. • •• .. -·. ~: . '.·' ,,, ·-·,: ~ .· ' '• . -~-~· ,, ' . ' , .. ,, :·._: . , . ~ ... , <,• • ., .. · ',' l. ·~ ; .... ._. ~ ' ,, '' .,. ~ '.: ,,-:,, ... :1. ~ . ' : :~ \' ~ ' ,,,:·, ·"·: : . :.~ ... ~-. J, :·\~. . :.:..·. ''•'' ,. :,, ..,J ' ... . ·,~ ',,., ,• ' .. -: :~..-' ,.: f ., • •, ~' f_ :,:,~' :' 1 '•' < ~\:-.::I ·· .. :' ··-·.,' ,...:· .. ,. ': i ·~ ,i • t ~.'-;:: ' ~: . ;,, . ., ',,.' ·'r· :-··,·',"':,,.' : : ' _..;' ,.' . ~' ," .' -,~_,·,'. "t .f, . :._' ·1:,•, ,!•." !, :.,,!': -.-.. '.-:,, ., .. ·,. \• . ··,,· .. 'I ,, • ·,1 :, ·~ ·- -, . •' . _;. : ~_ .... , ·~:, . '. ~. < .. .- , ... ,! ~, ,' . ·.~ ' ( -~ . -. : . ' .. . •\ ' •. ~·"!, .~ :· ', :., .. : -•,1 • , :. : 5. -' -~ \ ,_ •./. ,--' ,., ' ._;;. I, :-',('. . ..~·-. ·~ I I I I I I I I I I I I I I I I I I I APPENDIX A REFERENCES Blake, Thomas F., 1997, EQFAULT computer program and users manual for the deterministic prediction of horizontal accelerations from digitized California faults. Campbell, K.W., 1994, Empirical prediction of near-source ground motion from large earthquakes, in Johnson, J.A., Campbell, K.W., and Blake, eds., T.F., AEG Short Course, Seismic Hazard Analysis, June 18. · Greensfelder, R. W., 1974, Maximum credible rock acceleration from earthquakes in California: California Division of Mines and Geology, Map Sheet 23. Hart, E.W. and Bryant, W.A., 1997, Fault-rupture hazard zones in California: California Department of Conservation, Division of Mines and Geology, Special Publication 42. Housner, G. W., 1970, Strong ground motion in Earthquake Engineering, Robert Wiegel, ed., Prentice-Hall. International Conference of Building Officials, 1997, Uniform building code: Whittier, California. · Jennings, C.W., 1994, Fault activity map of California and adjacent areas: California Division of Mines and Geology, Map Sheet No. 6, scale 1 :750,000. Joyner, W.B, and Boore, D.M., 1994 a, Estimation of response-spectral values as functions of magnitude, distance and site conditions, in Johnson, J.A., Campbell, K.W., and Blake, eds., T.F., AEG Short Course, Seismic Hazard Analysis, June 18. __ ,.1994 b, Prediction of earthquake response spectra, in Johnson, J.A., Campbell, K. W., and Blake, eds.,T.F., AEG Short Course, Seismic Hazard Analysis, June 18. Sadigh, K., Egan, J., and Youngs, R., 1989, Predictive ground motion equations reported in Joyner, W.B., and Boore, D.M., 11Measurement, characterization, and prediction of strong ground motion11, in Earthquake Engineering and Soil Dynamics II, Recent Advances in Ground Motion Evaluation, Von Thun, J.L., ed.: American Society of Civil Engineers Geotechnical Special Publication No. 20, pp. 43-102. Sowers and Sowers, 1970, Unified soil classification system {After U. S. Waterways Experiment Station and ASTM 02487-667) in Introductory Soil Mechanics, New York. Tan, S.S., and Kennedy, Michael P., 1996, Geologic maps of the northwestern part of San Diego County, California: California Division of Mines and Geology, Open File Report 96-02. · · GeoSoils; lne. . i . ·, ,,1.,, ' -,' . ~ ,,,,.·:.· '·•, ',•. ·' ' .. :. ' .. ·'. ': 'I! ' '·,." , ,. ,.. ··\' ,-. ' .,, ., ;, . ~ .. •'':,.,; .>---1 . ) ",; .·• :~,. '• . -..... ,~ :·. : · .. ' -,-~~ ,..._ ,- 1. •, ;.\ ! ;/ '• , -: ,(.: ' ' ' • r • • • ! .·' 1-··., • • \A' ,,•' ':,:,, -:,·' ·._ ....... .. .,· ./ .. ,'\~ '.I-' -b:, ·-~·-' . ' : ,. ~ ,'', ',,, '·, --I' ',~•' ' . . ... ... .. , .. . ; ·. : ,.: .. , ,· ,.., ,.' ,-. --·~ -,_,. ,';1 ', ~·-. ', .- ' :·. ' ~ " . ~ i ··•. ',,,} '•• .. .· _.,. ' ·-(, : - . [·. , ,, l -:-·-: , .. , '. '' ,\.J -•. .• ·,' ,, < •\ ... '. - • j '_,! : .... ~ . . ~~ . : .. ' '·.:. .~ . .,. :.': • C , , r •,. ·,' .. ~ ·. ', .. • .. ''; ··., '· )' .. {.·· :,/·.··, _,,:, ; ;,'• ·;,.•\"'.!'., . ~-,,, \ ',' ·:.. ... ' .. , ,, 1, ••• I•.' ' ,!',. :,: .. + ;· ~ ,•, ~' '-~-:' ·: ' ;; :·:-\ ,- ' \./'· \.,:~\~-~-- •• , •t ··.:· . : ,, .. ,,. ~ ... , .. :~ l, ' ··'? , .. , !-.. :'· ~ _-, ·'. ',,,,- ' .... . ' ,•.t. _., .-1,,,; ... . ,-...... ,-•. ,· • • f • ~ ; f._ :, • '\ : ··,, .. ';! • ', ,v . . ' • !.' ~:;,.,. - -',( ~ ' .. -,, ~ ~ . .·-- .-,_:·:::, :.. .. , •, \, I";, '~,/'·;,.. ' . ... , _, ,.J : ~. · ... ··., ' -. : ·~, A. ~: ~ ••• • •• f '·'. { '.' :-·_. ~ . , : # ··: • .-,', '-·i' ',,. -•• ' t l \..--. ,, .. ' ... ~- .. ,._.., ··,, ,; 1. • ,,,,{ .. : -~ .... -,,, . . ~ .. .• : .,-,:• ,: : :' -•,\) . ~ --::-~ ~. ' " ,; • _ _l - · ......... ,. ',.-·,; ,, ::.,· J '.. ·/' , \ ( ' ·,· . ' . ~-~ , , . ,: ,,. _; ·. ~ , :, . •.' ·:·-· ...... .. ' ',.'' ·-~ . ·-·; ··_.:,,-,: ,::·,., '..,_• .. ~ a ' . ,• ~ :···:·,.--.--. . . ,, £..' ,-·,,, • ', >. ~.;, ;, .. . ' '• l ,.,_ .' . -~. •-" .. ·· .. , ·~ '..;·: .. ,, ' ~. . . \ '•~-. ...~·' ~ ,::, -..... t : - ,: '' .,· •'"!1<,... .. ,, -.·, ·-··-;-.· .. , .... · ', : • ' ~ ,, i '{,'_,;··: •.• J ·c.' -··,:-· . ,, ._,,,. ',-'_' .. _ ..... ,, :: ·: ,,.,. ,-.~} ,' .,-: ',/" ,• ., '-''< .~ ,' -, '-~ ", ,t_' -·: .. '·, , ,. · .. ~. ·:--:.· ,, • ... : •,. -.· ,.1 •• . .. ,-r.r. . :' .~-',c,.,:· . ' ~-.--~ ~ , ........ ;,' ";-_·'•I .... ··-_:,. .<l -:: ' .1 I I I I I: I I I I I I I I I I I 11 I GeoSoils, Inc. PROJECT: ED HENDRIX 470 Chinquapin Avenue Sample -~ "#. --E I Cl.):s :!i e? i ~~ §-::I -~ UE .!!! a, :5 t5.a en>-~ 0 C Ill Ill ::>en C :::i: ·cu ~M SM· 5- - - - - 10- - - - - 15- - ~ - - 20- - - - - 25- - - - - 470 Chinquapin Avenue -~ ~ C .Q e ::I 'tu en BORING LOG w.o. 3344-A-SC BORING 8-1 SHEEIJ_ OF 1 - DATE EXCAVATED 7-10-02 SAMPLE METHOD: HAND AUGER . m Standard Penetration Test ~ Undisturbed, Ring Sample A.I Water Seepage into hole Description of Material -~-· COLLUVIUMfTOPSOIL: r . '-!". · ,® 0-½' SIL TY SAND, brown, drv, loose· roots and rootlets . ,o..r-. : WEATHERED TERRACE DEPOSITS: .:..--. ,•:-,:,:,,• : @ ½-1' SIL TY SAND, orange brown, damp to moist, loose to medium :0: : \dense. I .v-. ·~·. TERRACE DEPOSITS: -~--IRi 1-4' SIL TY SAND, reddish brown, moist, medium dense to dense. r Total Depth= 4' No Groundwater Encountered Backfilled 7-10-02 - GeoSoils, Inc. PLATE B-1 I I I I I I ·I -1 1. I I I I I I I I I I GeoSoils, Inc. PROJECT: ED HENDRIX 470 Chinquapin Avenue Sample ....... ~C' c ~ E cn:S ~g_ ~ ..c ~i ! ::,-.a '5.. .:it!. UE 1/J :i -c-e ~ ·5 Cl), 6.a Cl) >, C al al ::> Cl) C :E ~u ~II.A SM - - 5- - - - - 10- - - - -· 15- - - - ~ 20- - - - - 25- - - - - 470 Chinquapin Avenue ....... ..,. -C ~ ::::, 1ii en BORING LOG w.o. 3344-A-SC BORING B-2 SHEEI_1_ OF 1 - DATE EXCAVATED 7-10-02 SAMPLE METHOD: HAND AUGER . m Standard Penetration Test -~ Undisturbed, Ring Sample I\# Water Seepage into hole Description of Material .-...r-.· COLLUVIUM/TOPSOIL: r . '-!"'.· ""' 0-½' SIL TY SAND, brown, drv, loose· roots and rootlets . , ,"(9',· WEATHERED TERRACE DEPOSITS: ,:..;., ':--":'" : \ 1 @ ½-1' SIL TY SAND, orange brown, damp to moist, loose to medium . ..,,.... ,../"'-, : dense. I -~-TERRACE DEPOSITS: . ..,,.... · , lfil 1-4' SIL TY SAND reddish brown moist. medium dense to dense. r Total Depth = 4' No Groundwater Encountered Backfilled 7-10-02 - GeoSoils, Inc. PLATE B-2 I I I I I I I I I I I I I I I I BORING LOG GeoSoils, Inc. w.o .. __ 3344 __ -A_-s_c __ PROJECT: ED HENDRIX BORING B-3 SHEEIJ_ OF_1_ 470 Chinquapin Avenue DATE EXCAVATED ____ 7_-1....;.0_-0_2 ___ _ Sample SAMPLE METHOD,_: _H_A_ND_A_UG_E_R _____________ _ -~ $ E rn:S ~ cs I °C c:: C. i ~~ .! ::::,- ~ UE ~ CD "5 1:5::::, rn >-C IX! ,-CD ::::>rn C m· Standard Penetration Test ~ Undisturbed, Ring Sample ~ Water Seepage into hole Description of Material c:u C:P.A SM ~---,--l----1---...j;.·.:;..'-('..;..J-,· · COLLUVIUM/TOPSOIL: · '-('_ · -=--0-½' SIL TY SAND, brown drv, loose: roots and rootlets. r : ~:: WEATHERED TERRACE DEPOSITS: - - ... ·:-r.·. @ ½-1' SIL TY SAND, orange brown, damp to moist, loose to medium :t:: dense. I · _;....-:..: TERRACE DEPOSITS: -1---1--1----1---1-----i----1----i-=·..,,,.=· ·-'h· ·, rm 1-4' SIL TY SAND, reddish brown moist medium dense to dense. /" 5- . . · 10- - - . 15- . . - - 20- - - . 25- - - - 470 Chinquapin Avenue Total Depth= 4' No Groundwater Encountered Backfilled 7-10-02 GeoSoils, Inc. PLATE B-3 I I I I I I I I I I I I ·1 I I I I I I GeoSoils, Inc. PROJECT: ED HENDRIX 470 Chinquapin Avenue Sample ...... '#. ...... Q) ..... .a .!!! 0 :E BORING LOG BORING 8-4 w.o •. __ 33_4_4-_A_-s_c __ SHEE[J_ OF_1_ ~~~~~~D~ ___ 7_-_10~-_02 ___ _ SAMPLE METHOD,_: _H_A_ND_A_UG_E_R _____________ _ ~ ffl Standard Penetration Test ...... j ~ Undisturbed, Ring Sample 1,-C' ,s 1------------.-.---------------l- ci.i Description of Material 1\# Water Seepage into hole SM . '-('. · ARTIFICIAL FILL: -11--_-_-r_-_--+t-_-_-_--1tc~~l4j"::::::::::::.t::::::j"~::::::..r·....:;""::;;; ...;.+,·:4-:....,_~1mo~-:.!.1 '~S~IL!::..TY!..!...:S~A~Nl!!, D-:!.J,~b~ro~w!!.n!L.'· ~drv!.I.!...!, l~oo~s~e:i..· ~ro~o!!:ts~a!:!.!n~d!..!r~oo~t~le~ts!.:.... ____ --Jr - 5- - - - -, 10- - - - 15- - - - - 20- - - - - 25- - - - - ~u ::·: COLLUVIUM/TOPSOIL: , SM :.:;,.:. I® 1-1½' SILTY SAND, brown, drv, loose. 'r · "'· .. WEATHERED TERRACE DEPOSITS: ::;::: \In) 1½-2' SILTY SAND oranoe brown, moist. medium dense . . · ._. · TERRACE DEPOSITS: ! \ @ 2-4' SIL TY SAND, reddish brown, moist, medium dense to dense with death. Total Depth = 4' No Groundwater Encountered Backfilled 7-10-02 470 Chinquapin Avenue GeoSoils, Inc. PLATE 8-4 ,_',• •' :~. •,', ' r ', •• ' ;)l:i/\ti ' .. \ ·. .., .·. -.. ·.,. . ~ ~: . ,• ; :' ' ·, ' ·: -~ - : ~ , _,,·; ·,l'· <1_:; ' . ' \. ··,·.· ., .. ,,.,' ;, •.,,, . ~. ' ' I ~/ ~ • • I . ·~, ?, .. ' : ~' I·~•' ' ,, ..... .··: .. , •'!I'• ;·, ,·. ·'. '--.'.• .. ' ·.~ ·. :.~ . ·:" · .. • I ,··' < ·, • .::' -~ 1 • ',·1· ...... ,.·:·, .. •', .-· ·,,·_:· .. ,· 1. .r.-' ... ~ ,' • ._', I . ;, : ~ ) . . ~ .J. .... '• ; ;; ·,\,., . -., ',' ,,.•, .... _. ·--··· ·, ._,_ \ ,. . ,,~ ' .. , ·,. ·, .·1 · ,.:•.· ··-,,"' . :. , ", ,_ .. -/, ; ',•. ·:·, ., ' > ~ ',,. '· ', .~ t ... ,\ :; : '( .· /' . ';, '· >·:,_-;_ .. ·J ,,.'' '! •• , t ',, .-,,_.· '': I ... ;-,.,.f,, ••• 1 • ' ,. 'C • ,·,. ''\'• ,..__,. ... -,',· ·.·;· ';·\ ~--' ·.'·· .. -:../.• .,. ,,. ,· ·:::"-'"' ' ... I .·,. ,· .. \,., ,, ,, ' ,1 • : ,i. {~ • .. ,/ '· ~. ' : ~-- ' -. ,: ~-, .. . -. ,· •, .,. ': ~:;/ "). l ~ ;,', .·, 'L:.~/ .. • ' .. . ,, :·, .. ~-·,~ ', -~l -: ' .,,, ',. ,. ,· .'. ,,:: ·-~--... ' --.' ,·,. ~ ;::1 I • l'' ,. ... , ,. '. -·, ,I -·:.-... .-. ;. :'' :;~:'. :~~ _,. ; -, ! 1.; 1,,-•' ·,,, . .· .. ; \ .,-,,_ 't;. ·1.,· ·. : . ·.~' ~ ::. ; •',I '·-i ,,t, ,,,· " .... ,. . ,:· .. . ,_, ... ,, .,,: ... y;, . . ·~ 1: ·/,. {' --~· , ' .• •,1 . 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Carlsbad, CA 92008 Telephone: (760) 438-3155 Fax: (760) 931-0915 Sample Type 'Yci MC% c Remolded 120.1 9.5 177 Remolded 120.1 9.5 165 DIRECT SHEAR TEST Project: HENDRIX Number: 3344-A-SC Date: July 2002 Figure: C-1 33 31 .... ______________________________________ .. ;·• r: ,:..;~·. : " ";'• ~-'1': • •.• ; , .: .~ •. • r'-. \ ,., . -·-•,'.' ' . ',\. ~ .... _ ,, ---·1 ' ' ~ ' •-.. ,··-· .. _ ... -· /_',,''. '•·/, ·' . ;::; . - I.:._. '' •,:·- \ . ,· ',1', ..... :.i ', • .._-,, ,> ,, l, ·; ~· : •,, :,./. ., ,._, :,·:·,, _., •. ~: -,:.:"~ .. • '• . -~ ' ; .. , ,. ... , .. ·.-.-.·.· '. ' '· . , . '·. ;~-, :· ",-,• .. , . I , • • ' ' ',• -~ '.· .~ .,· '. ,,_. .' -~ . , ),,• : . .: ""· .. ,:',, •.- .,,,--;_• ,·I\}' I ', '','-;, ' -~' . . . . .~ •.. • ~ • I ' : • ·~, f ; •'/• ,·>~ :'.··.:•.' .-.. _.'::,_ .. , ... :, . ',:~', -:,:-:' ... ;:{ .. ~-~-. 1·, ."..: 1··:,.,._'': -. '•' ·.:·· ,: ...... ·,< .. '-· ~· '·' ' :·, •' ·, ... ,• ·, ',,',' ··: ·.' ,,' . ·' . ,, , ',"'. ,',,·: ,· , •. '" ,~· I ·., ·~, • I I•'' ·:.:: ·.:·:-,:·t\·:{,,:.: ~-! .{, ,:.:'.', ~ ~_..··, : ,·· ·,,;,·.~ '·." -~ . . '''°-: ..... ·t-·, '_;·· :, ,, ', / :· ~· ' ' ':.~.·: .. , . .. • • <, ·' 1, ' '··~ '! ' ·,' •• > • -: L '" ~ T : .,_,_ ... :· ·v,' . . ' ; ,-. ,.'--~ .. .,' ~I.::~ ·, ,. ~. ' · .. . "~ .. .. ,, , ' " '~ '; ~, ', ,, ;-v, :,·,.-,.:' ~ ., ,-, ::-~.' . ,. . ~· '. ... ,,:;,·'. ·' i•--:.'_ ···:, ; ::·· ·~ : ,· . ·. :··· ,,: . , l,'.,::: :. ·. ;. \_ :-:_' ,:.~ '': . ' . • • .f ', •• .:.!,_.'·, I .1; • ,. '• • ~I• , ; ·.' > ' .. -·~ ·;· .... ·,',,," -·. ~, -.~ .,._, .. . ... . ;, . ·. .,t ..... _ , ,· ,··J l ',, '.> J, • '•, --~ .. . ','•' .•·.·'- ' \ ~. . . /,\ ·-,';' -_..,,.,. l ·: • '11'" ~· ".: ,· t.-.... •.!_ , ~.. I, ·::< :, ~ ,,_,:\· '--~' _;, ·-,. : •;·;· _,, .' ', •,',, ·-,'. J. ::, .',; .~ :-· ' -. ; ~ . ' •,, ,'',• . ' ',•"'". .. ~-,: , ( . <':.·, ·' ,, ,:,,,),.-.. _ ... ,; ',. ;: ·_,. ~ _, ,_·;~ .\-,_ .... ·, r ~ [ .. i: ·., r ·,,·· • .:: ·' •-1; -~ ·' :,:·,.,. ' ,,", ,:· J :, '~ , ~ ,.. • _i : -~ 'l . 1: ·~ . - ... ~' " ·-~··. _...,.' .. : ,-::...; ,, :,.',_ .... ,. I I -I I -I I I I I I I I I I I I I I I GENERAL EARTHWORK AND GRADING GUIDELINES General These guidelines present general procedures and requirements for earthwork and grading as shown on the approved grading. plans, including preparation of areas to filled, placement of fill, installation of subdrains and excavations. The recommendations contained in the geotechnical report are part of the earthwork and grading guidelines and would supersede the provisions contained hereafter in the case of conflict. Evaluations performed by the consultant during the course of grading may result in new recommendations which could supersede these guidelines or the recommendations contained in the geotechnical report. The contractor is responsible for the satisfactory completion of all earthwork in accordance with provisions of the project plans .and specifications. The project soil engineer and engineering geologist (geotechnical consultant) or their representatives should provide observation and testing services, and geotechnical consultation during the duration of the project.· EARTHWORK OBSERVATIONS AND TESTING Geotechnlcal Consultant Prior to the commencement of grading, a qualified geotechnical consultant (soil engineer and engineering geologist) should be employed for the purpose of observing earthwork procedures and testing the fills for conformance with the recommendations of the geotechnical report, the approved grading plans, and applicable grading qodes and ordinances. The geotechnical consultant should provide testing and observation so that determination may be made that the work is being accomplished as specified. It is the responsibility of the contractor to· assist the consultants and keep them apprised of anticipated work schedules and changes, so that they may schedule their personnel accordingly. All clean-outs, prepared ground to receive fill, key excavations, and subdrains should be observed and documented by the project engineering geologist and/or soil engineer prior to placing and fill. It is the contractors's responsibility to notify the engineering geologist and soil engineer when such areas are ready for observation. Laboratory and Field Tests Maximum dry density tests to determine the degree of compaction should be performed in accordance with American Standard Testing Materials test method ASTM designation D- 1557-78. Random field compaction tests should be performed in accordance with test method ASTM designation 'D-1556-82, D-2937 or D-2922 and D-3017, at intervals of ~pproximately 2 feet of fill height or every 1 oo cubic yards of fill placed. These criteria would vary depending on the soil conditions-and the size of the project. The location and frequency of testing would be at the discretion of the geotechnical consultant. GeoSoils, Ine. I I I I I I I I I I I I I I I I I I I Contractor's Responsibility All clearing, site preparation, and earthwork performed on the project should be conducted by the contractor, with observation by geotechnical consultants and staged approval by the governing agencies, as applicable. It is the contractor's responsibility to prepare the ground surface to receive the fill, to the satisfaction of the soil engineer, and to place, spread, moisture condition, mix and compactthe fill in accordance with the recommendations of the soil engineer. The contractor should also remove all major noR-earth material considered unsatisfactory by the soil engineer. It is the sole responsibility of the contractorto provide adequate equipment and methods to accomplish the earthwork in accordance with applicable grading guidelines, codes or agency ordinances, and approved grading plans. Sufficient watering apparatus and compaction equipment should be provided by the contractor with due consideration for the fill material, rate of placement, and climatic conditions. If, in the opinion of the geotechnical consultant, unsatisfactory conditions such as questionable weather, excessive oversized rock, or deleterious material, insufficient support equipment, etc., are resulting in a quality of work that is not acceptable, the consultant will inform the contractor, and the contractor is expected to rectify the conditions, and if necessary, stop work until conditions are satisfactory. During construction, the contractor shall properly grade all surfaces to maintain good drainage and prevent ponding of water. The contractor shall take remedial measures to control surface water and to prevent erosion of graded areas until such time as permanent drainage and erosion control measures have been installed. SITE PREPARATION All major vegetation, including brush, trees, thick grasses, organic debris, and other deleterious material should be removed and disposed of off-site. These removals must be concluded prior to placing fill. Existing fill, soil, alluvium, colluvium, or rock materials determined by the soil engineer or engineering geologist as being unsuitable in-place should be removed prior to fill placement. Depending upon the soil conditions, these materials may be reused as compacted fills. Any materials incorporated as part of the compacted fills should be approved by the soil engineer. Any underground structures such as cesspools, cisterns, mining shafts, tunnels, septic · tanks, wells, pipelines, or other structures not located prior to grading are to be removed or treated in a manner recommended by the soil engineer. Soft, dry, spongy, highly fractured, or otherwise unsuitable ground extending to such a depth that surface processing cannot adequately improve the condition shq4ld be overexcavated down to firm ground and approved by the soil engineer before compaction and filling operations continue. Overexcavated and processed soils which have been properly mixed and moisture conditioned should be re-compacted to the minimum relative compaction as specified in these guidelines. . Mr. Ed Hendrix File:e:\wp7\3300\3344a.pge GeoSoils, lne. Appendix D Page2 I I I I I I I I I I I I I I I I I' I I Existing ground which is determined to be satisfactory for support of the fills should be scarified to a minimum depth of 6 inches or as directed by the soil engineer. After the scarified ground is brought to optimum moisture content or greater and mixed, the materials should be compacted as specified herein. If the scarified zone is grater that 6 inches in depth, it may be necessary to remove the excess and place the material in lifts restricted to about 6 inches in compacted thickness. Existing ground which is not satisfactory to support compacted fm should be overexcavated as required in the geotechnical report or by the on-site soils engineer and/or engineering geologist. Scarification, disc harrowing, or other acceptable f9rm of mixing should continue until the soils are broken down arid free of large lumps or clods, until the working surface is reasonably uniform and free from ruts, hollow, hummocks, or other uneven features which would inhibit compaction as described previously. Where fills are to be placed on ground with slopes steeper than 5: 1 (horizontal to vertical), the ground should be stepped or benched. The lowest bench, which will act as a key, should be a minimum of 15 feet wide and should be at least 2 feet deep into firm material, and approved by the soil engineer and/or engineering geologist. In fill over cut slope conditions, the recommended minimum width of the lowest bench or key is also 15 feet with the key founded on firm material, as designated by the Geotechnical Consultant. As a general rule, unless specifically recommended otherwise by the Soil Engineer, the minimum width of fill keys should be approximately equal to ½ the height of the slope. Standard benching is generally 4 feet (minimum) vertically, exposing firm, acceptable material. Benching may be used to remove unsuitable materials, although it is understood that the vertical height of the bench may exceed 4 feet. Pre-stripping may be considered for unsuitable materials in excess of 4 feet in thickness. All areas to receive fill, including processed areas, removal areas, and the toe of fill benches should be observed and approved by the soil engineer and/or engineering geologist prior to placement of fill. Fills may then be properly placed and compacted until design grades (elevations) are attained. COMPACTED FILLS Any earth materials imported or excavated on the property may be utilized in the fill provided that each material has been determined to be suitable by the soil engineer. These materials should be free of roots, tree branches, other organic matter or other deleterious materials. All unsuitable materials should be removed from the fill as directed by the soil engineer. Soils of poor gradation, undesirable expansion potential, or substandard strength characteristics may be designated by the consultant as unsuitable and may require blending with other soils to serve as a satisfactory fill material. Fill materials derived from benching operations should be dispersed throughoutthe fill area and blended with other bedrock derived material. Benching operations should not result Mr. Ed Hendrix File:e:\wp7\3300\3344a.pge GeoSoils, lne. Appendix D Page3 I I I I I I I I I I I I I I I I I I I I in the benched material being placed only within a single equipment width away from the fill/bedrock .contact. Oversized materials defined as rock or other irreducible materials with a maximum dimension greater than 12 inches should not be buried or placed in fills unless the location of materials and disposal methods are specifically approved by the soil engineer. Oversized material should be taken off-site or placed in accordance with recommendations of the soil engineer in areas designated as suitable for rock disposal. Oversized material should not be placed within 10 feet vertically of finish grade (elevation) or within 20 feet horizontally of slope faces. To facilitate future trenching, rock should not be placed within the range of foundation excavations, future utilities, or underground construction unless specifically approved by the soil engineer._and/or the developers representative. If import material is required for grading, representative samples of the materials to be utilized as compacted fill should be analyzed in the laboratory by the soil engineer to determine its physical properties. If any material other than that previously tested is encountered during grading, an appropriate analysis of this material should be conducted by the soil engineer as soon as possible. Approved fill material should be placed in areas prepared to receive fill in near horizontal layers that when compacted should not exceed 6 inches in thickness. The soil engineer rriay approve thick lifts if testing indicates the grading procedures are such that adequate compaction is being achfeved with lifts of greater thickness. Each layer should be spread evenly and blended to attain uniformity of material and moisture suitable for compaction. Fill layers at a moisture content less than optimum should be watered and mixed, and wet fill layers should be aerated by scarification or should be blended with drier material. Moisture condition, blending, and mixing of the fill layer should continue until the fill materials have a uniform moisture content at or above optimum moisture. After each layer has been evenly spread, moisture conditioned and mixed, it should be uniformly compacted to a minimum of 90 percent of maximum density as determined by ASTM test designation, D-1557-78, or as otherwise recommended by the soil engineer. Compaction equipment should be adequately sized and should be specifically designed for soil compaction or of proven reliability to efficiently achieve the specified degree of compaction. Mr. Ed Hendrix File:e:\wp7\3300\3344a.pge GeoSoils, lne. Appendix D Page4 I I I I I I I I- I I I I I I -,I I I 1· I Where tests indicate that the density of any layer of fill, or portion thereof, is below the required relative compaction, or improper moisture is in evidence, the particular layer or portion shall be re-worked until the required density and/or moisture content has been attained. No additional fill shall be placed in an area until the last placed lift of fill has been tested and found to meet the density and moisture requirements, and is approved by the soil engineer. · Compaction of slopes should be accomplished by over-buikfing a minimum of 3 feet horizontally, and subsequently trimming back to the design slope configuration. Testing shall be performed as the fill i~ elevated to evaluate comp~ction as the fill core is being developed. Special efforts may be necessary to attain the specified compaction in the fill slope zone. Final slope shaping should be performed by trimming and removing loose materials with appropriate equipment. A final determination of fill slope compaction should be based on observation and/or testing of the finished slope face. Where compacted fill slopes are designed steeper than 2:1 (horizontal to vertical), specific material types, a higher minimum relative compaction, and special grading procedures, may be recommended. If an alternative to over-building and cutting back the compacted fill slopes is selected, then special effort should be made to achieve the required compaction in the outer 1 o feet of each lift of fill by undertaking the following: 1. 2. 3. 4. 5. An extra piece of equipment consisting of a heavy short shanked sheepsfoot should be used to roll (horizontal) parallel to the slopes continuously as fill is placed. The sheepsfoot roller should alsobe used to roll perpendicular to the slopes, and extend out over the slope to provide adequate compaction to the face of the slope. · Loose fill should not be spilled out over the face of the slope as each lift is compacted. Any loose fill spilled over a previously completed slope face should be trimmed off or be subject to re-rolling. Field compaction tests will be made in the outer (horizontal) 2 to 8 feet of the slope at appropriate vertical intervals, subsequent to compaction operations. After completion of the slope, the slope face should be shaped with a small tractor and then re-rolled with a sheepsfoot to achieve compaction to near the slope face. Subsequent to testing to verify compaction, the slopes should be grid-rolled to achieve compaction to the slope face. Final testing should be used to confirm compaction after grid rolling. Where testing indicates less than adequate compaction, the contractor will be responsible to rip, water, mix ~nd. re-compact the slope material as necessary to achieve compaction. Additional testing should be performed to verify compaction. Mr. Ed Hendrix File:e:\wp7\3300\3344a.pge Appendix D Pages GeoSoils, lne. I I I I I· I I I I I I I I I ·1 I I I I 6. Erosion control and drainage devices should be designed by the project civil engineer in compliance with ordinances of the controlling governmental agencies, and/or in accordance with the recommendation of the soil engineer or engineering geologist. SUBDRAIN INSTALLATION Subdrains should be installed in approved ground in accordance with the approximate alignment and details indicated by the geotechnical cons1.:1ltant. Subdrain locations or materials should not be changed or modified without approval of the geotechnical consultant. The soil engineer and/or engineering geologist may recommend and direct changes in subdrain line, grade and drain material in the field, pending exposed conditions. The location of constructed subdrains should be recorded by the project civil engineer. EXCAVATIONS Excavations and cut slopes should be examined during grading by the engineering geologist. If directed by the engineering geologist, further excavations or overexcavation and re-filling of cut areas should be performed and/or remedial grading of cut slopes should be performed. When fill over cut slopes are to be graded, unless otherwise approved, the cut portion of the slope should be observed by the engineering geologist prior to placement of materials for construction of the fill portion of the slope. The engineering geologist should observe all cut slopes and should be notified by the .contractor when cut slopes are started. If, during the course of grading, unforeseen adverse or potential adverse geologic conditions are encountered, the engineering geologist and soil engineer should investigate, evaluate and make recommendations to treat these problems. The need for cut slope buttressing or stabilizing should be based on in-grading. evaluation by the engineering geologist, whether anticipated or not. Unless . otherwise specified in soil and geological reports, no cut slopes should be excavated higher or steeper than that allowed by the ordinances of controlling governmental agencies. Additionally, short-term stability of temporary cut slopes is the contractors responsibility. Erosion control and drainage devices should be designed by the project civil engineer and should be constructed in compliance with the ordinances of the controlling governmental agencies, and/or in accordance with tt,e recommendations of the soil engineer or engineering geologist. ' Mr. Ed Hendrix File:e:\wp7\3300\3344a.pge GeoSoils, lne. Appendix D Page6 I I 1· I I I I I ·1 I I I I I I I I I I COMPLETION Observation, testing and consultation by the geotechnical consultant should be conducted during the grading operations in order to state an opinion that all cut and filled areas are graded in accordance with the approved project specifications. After completion of grading and after the soil engineer and engineering geologist have finished their observations of the work, final reports should be submitted subject to review by the controlling governmental agencies. No further excavation or filling should be undertaken without prior notification of the soil engineer anq/or engineering geologist. All finished cut and fill slopes should be protected from erosion and/or be planted in accordance with the project specifications and/or as recommended by a landscape architect. Such protection and/or planning should be undertaken as soon as practical after completion -of grading. JOB SAFETY General At GeoSoils, Inc. (GSI) getting the job done safely is of primary concern. The following is the company's safety considerations for use by all employees on multi-employer construction sites. On ground personnel are at highest risk of injury and possible fatality on grading and construction projects. GSI recognizes that construction activities will vary on each site and that site safety is the prime responsibility of the contractor; however, everyone must be safety conscious and responsible at all times. To achieve our goal of avoiding accidents, cooperation betwee·n the client, the contractor and GSI personnel must be maintained. In an effort to minimize risks associated with geotechnical testing and observation, the following precautions are to be implementE;!.d for the safety of field personnel on grading and construction projects: Safety Meetings: GSI field personnel are directed to attend contractors regularly scheduled and documented safety meetings. Safety Vests: Safety Flags: Mr. Ed Hendrix File:e:\wp7\3300\3344a.pge Safety vests are provided for and are to be worn by GSI personnel at all times when they are working in the field. Two safety flags are provided to GSI field technicians; one is to be affixed to the vehicl~ when on site, the other is to be placed atop the spoil pile on all test pits. Geo.Soils, Ine. r. Appendix D Page? I I I I I I I I I I I I I I I I ·1 I I I Flashing Lights: All vehicles stationary in the grading area shall use rotating or flashing amber beacon, or strobe lights, on the vehicle during all field testing. While operating a vehicle in the grading area, the emergency flasher on the vehicle shall be activated. In the event that the contractor's representative observes any of our personnel not following the above, we request that it be brought to the attention of our office. Test Pits Location, Orientation and Clearance The technician is responsible for selecting test pit locations. ·A primary concern should be the technicians's safety. Efforts will be made to coordinate locations with the grading contractors authorized representative, and to select locations following or behind the established traffic pattern, preferably outside of current traffic. The contractors authorized representative (dump man, operator, supervisor, grade checker, etc.) should direct excavation of the pit and safety during the test period. Of paramount concern should be the soil technicians safety and obtaining enough tests to represent the fill. Test pits should be excavated so that the spoil pile is placed away form oncoming traffic, whenever possible. The technician's vehicle is to be placed next to the test pit, opposite the spoil pile. This necessitates the fill be maintained in a driveable condition. Alternatively, the contractor may wish to park a piece of equipment in front of the test holes, particularly in small fill areas or those with limited access. A zone of non-encroachment should be established for all test pits. No grading equipment should enter this zone during the testing procedure. The zone should extend approximately 50 feet outward from the center of the test pit. This zone is established for safety and to avoid excessive ground vibration which typically decreased test results. When taking slope tests the technician should park the vehicle directly above or below the test location. If this is not possible, a prominentflag should be placed atthe top of the slope. The contractor's representative should effectively keep all equipment at a safe operation · distance (e.g., 50 feet) away from the slope durin_g this testing. The technician is directed to withdraw from the active portion of the fill as soon as possible following testing. The technician's vehicle should be parked at the perimeter of the fill in a highly visible location, well away from the equipment traffic pattern. The contractor should inform our personnel of all changes to haul roads, cut and fill areas or other factors that may affect site access and site safety. In the event that the technicians safety is jeopardized or compromised as a result of the contractors failure to comply with any of tne above, the technician is required, by company policy, to immediately withdraw and notify his/her supervisor. The grading contractors representative will eventually be contacted in an effort to effect a solution. However, in the interim, no further testing will be performed until the situation is rectified. Any fill place can be considered unacceptable and subject to reprocessing, recompaction or removal. Mr. Ed Hendrix File:e:\wp7\3300\3344a.pge GeoSoils, Ine .. Appendix D Pages I I I I I I I I I I I I I I I I I I I In the event that the soil technician does not comply with the above or other established safety guidelines, we request thatthe contractor brings this to his/her attention and notify this office. Effective communication and coordination between the contractors representative and the soils technician is strongly encouraged in order to implement the above safety plan. Trench and Vertical Excavation It is the contractor1s responsibility to provide safe access into trenches where compaction testing is needed. Our personnel are directed not to enter any excavation or vertical cut which: 1) is 5 feet or deeper unless shored or laid back; 2) displays any evidence of instability, has any loose rock or other debris which could fall into the trench; or 3) displays any other evidence of any unsafe conditions regardless of depth, All trench excavations or vertical cuts in excess of 5 feet deep, which any person enters, should be shored or laid back.· Trench access should be provided in accordance with CAL-OSHA and/or state and local standards. Our personnel are directed not to enter any trench by being lowered or 11riding down11 on the equipment. If the contractor fails to provide safe access to trenches for compaction testing, our company policy requires that the soil technician withdraw and notify his/her supervisor. The contractors representative will eventually be contacted in an effort to effect a solution. All backfill not tested due to safety concerns or other reasons could be subject to reprocessing and/or removal. If GSI personnel become aware of anyone working beneath an unsafe trench wall or vertical excavation, we have a legal obligation to put the contractor and owner/developer on notice to immediately correct the situation. If corrective steps are not taken, GSI then has ·an obligation to notify CAL-OSHA and/or the proper authorities. Mr. Ed Hendrix File:e:\wp7\3300\3344a.pge · GeoSoils, Jne. Appendix D Page9 I ·" rl I I I I I I I I I I I I I I I I I ,. CANYON SU BO RAIN DETAIL TYPE A PROPOSED COMPACTED FILL TYPE B -...-.---------------------------------- , PROPOSED COMPACTED Fill ' ' ' . _, ', _ _,.-NATURAL GROUND =~ '* . 11,\~/) ', NOTE: ALTERNATIVES, LOCATION ANO EXTENT OF SUBDRAINS SHOULD BE DETERMINED 9y· TH-E SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST·O URING GRADING. PLATE EG-1 I I CANYON SUBDRAIN ALTERNATE DETAILS I I I I ·1 I I I I I I ·1 I I I. I I : ALTERNATE 1: PERFORATED PIPE AND FILiER MATERIAL ·A-1 ·FILTER MATERIAL. . SIEVE SIZE PERCENT PASSING 1 INCH ,100 ·3/4 INCH 90-:-:100 3/8 INCH 40-100 NO. 4 25-40. NO. 8 18-33 .NO. 30 :S-15 "NO. 50 .0-7. NO. 200 0-3 ALTERNATE 2: PERFORATED PIPE, GRAVEL AND.FILTER FABRIC ~Nl~UM OVERLAP 5• MINIMUM OVER~~, A-2 PERFORATEO PIPE: SEE ALTERNATE 1 GRAVEL: CLEAN 3/ 4 IND-I ROCK OR APPROVED SUBSTITUTE FILTER FABRIC: MIRAFI 140 OR APPROVED SUBSTITUTE PLATE EG-2 I .1 I I I I ·1 I I I I I I I I I I I -I· DET All FOR FILL. SLOPE TOEING OUT ON FLAT ALLUVlA TED CANYON TOE OF SLOPE AS SHOWN ON GRADING PLAN ORIGINAL GROUND SURFACE TO BE RESTORED WITH COMPACTED FILL . -:2-::0~IGl:L_:a_:~u~~ BACKCU~ VARIES. FOR DEEP REMOVALS,~~ r BACKCUT ~~SHOULD s·E MADE NO ($-~ STEEPER·THA~:1 OR AS NECESSARY.,~) ANTICIPATED ALLUVIAL REMOVAL FOR SAFETY .........._~,cONSIDERATIONS7 ' 1 ~ DEPTH PER SOIL ENGINEER. ~}k~ ,,/ . - ~1th.,/\ . -- ·1/\'\vj~rf~---PROVIOEA 1:1 ;;,MUMPRo:iEcnoNFROM T; OF SLOPE AS SHOWN ON GRADING PLAN TO THE RECOMMENDED REMOVAL DEPTH. SLOPE HEIGHT, SITE CONDITIONS ANO/OR LOCAL CONDITIONS COULD DICTATE FLATTER PROJECTIONS. REMOVAL ADJACENT TO EXISTING FILL ADJOINING CANYON FILL ----------:------------ PROPOSED ADDITIONAL COMPACTED F.ILL . COMPACTED FILL LIMITS LIN!;\ ~ TEMPORARY .COMPACTED FILL --...~ --- . ), FOR DRAINAGE ONLY ------ Oaf ..,.:r;0, Oaf /'Clal (TO BE REMOVED> IEXISTING,COMPACTEO ALU ~',, ~.,, ~'\\~~//~\ k~~R1'~ ' LEGEND '7/J5.f/j~'/\ . :...-\\ TO BE REMOVED BEFORE Oaf ARTIFICIAL FILL PLACING ADDITIONAL COMPACTED FILL . Qa( ALLUVIUM PLATE EG-3 --· ----· -·--. ----· ------·- -u r )> -; m m G') I +- TYPICAL STABILIZATION / BUTTRESS. FILL DETAIL 15" TYPICAL 1-2' v1..&..n1~ ,....,. >>JC I> ,,_, t. OUTLETS TO BE SPACED AT 100' MAXIMUM INTERVALS, AND SHALL EXTEND 1r BEYOND THE FACE PF SLOPE AT TIME OF .R.OUGH GRADING COMPLETION. le · ti . 15' MINIMUM BLANKl:T FILL IF RECOMMENDED BY THE SOIL ENGINEER DESIGN· FINISH SLOPE L. ,,, »K\ '\\Vifillb _____ _ ~ I ~ .,, , 4 i · · ·--1 -4• DIAMETER NON-PERFORATED OUTLET PIPE _J_ . ANO BACKDRAIN,(SEE ALTERNATIVESJ ~)'' 3' MINIMUM KEY DEPTH ------·---· --... -----.. --. . .. \. . . . . TYPICAL STABILIZATION /_ BUTTRESS SUB·DRAIN DETAIL L • MINIMUM r MINIMUM PIPE L. MINIMUM -u r )> -I m m G) I U1 PIPE :E :::, ~ ~ :E . N r MINIMUM FILTER f:tATERIAL: MINIMUM OF FIVE Fl,/LINEAR Fl OF PIPF. OR FOUR FP/LINEAR Ft OF PIPE WHEN PLACED IN SQUARE CUT TRENCH. AI.I~RNATIVE IN LIEU OF FILTER MATERIAL: GRAVEL MAY e EHCA~EO IN APPROVED FILTER FABRIC. FILTER FABRIC SHALL ~E MIRAFI 140 OR EQUIVALENT. FILTER FABRIC SJJALL BE LAPPED A MINIMUM OF 1r ON ALL JOINTS. MINIMUM 4• DIAMETER PIPE: ABS-ASTM D-2751. SOR 35 OR ASTM D-1527 SCHEDULE 40 PVC-ASTM D-3034, SPR _35_ OR ASTM D-1785 SCHEDULE 40 WI.TH A CRUSHING STRE~OTH OF 1,000 POUNDS MINIMUM, ANO A MINIMUM OF 8 UNIFORMLY SPACED PERFORATIONS PER FOOT OF PIPE INSTALLED WITH PERFORATIONS OF BOTTOM OF PIPE. PROVIDE CAfl AT UPSTREAM END OF PIPE_. SLOPE AT 2% TO OUTLET P.IPE. OUTLET PIPE TO BE CONNECTED TO SUBDRAIN PIPE WITH TEE OR ELBOW. . NlTE:: 1. TRENCH FOR OUTLET PIPES TO BE BACKFILLED ' WITH ON-SITE SOIL. 2. BACKORAINS ANO LATERAL DRAINS SHALL BE LOCATED AT ELEVATION OF EVERY BENCH DRAIN. FIRST DRAIN LOCATED AT ELEVATION JUST ABOVE LOWER LOT GRADE. ADDITIONAL DRAINS MAY BE REQUIRED AT THE DISCRETION OF THE SOILS ENGINEER AND/OR ENGINEERING QEOLOGIST. FILTER MATERIAL SHALL BE OF THE FOLLOWING SPECIFICATION OR AN APPROVED EQUIVALENT: SIEVE SIZE PERCENT PASSING 1 INCH 100 3/4 INCH ~0-100 3/8 INc;:H 40-100 NO. 4 25-40 N0.8 18-33 NO. JO 5-15 NO. 50 0-7 N0.200 o-~ GRAVEL SHALL BE OF THE FOLLOWING SPECIFICATION OR . AN APPROVED E~UIVALENT: . SIEVE SIZE PERCENT PASSING 1 1 /2 IN CH.. 1 0 0 NO. 4 50 N0.200 8 SAND EQUIVALENT: MINIMUM OF 51 ,, ----·--· --·-----·---·--- FILL OVER NATURAL DETAIL SIDEHILL FILL TOE OF SLOPE AS SHOWN ON GRADING PLAN PROVIDE A 1:1 MINIMUM PROJECTION FROM DESIGN' TOE OF SLOPE TO TOE OF l<~Y AS SHOWN ON AS BUILT NATURAL SLOPE TO BE RESTORED WITH ~ -1 I ~:MINIM~M BENCH WIDTH MAY VARY COMPACTED FILL ~ NOTE: 1. WHERE THE NA'tURAL, SLOPE APPROACHES OR EXCEE-0S THE -0 r )> -I m m G> I Ol 15"MINIMUM KEY WIDTH DESIGN SLOPE RATIO. SPECIAL RECOMMENDATIONS WOULD BE 2'X 3' MINIMUM KEY DEPTH 2· MINIMUM IN BEDROCK OR APPROVED MATERIAL. I PROVIDED BY THE SOILS ENGINEER. 2. THE NEED FOR AND DISPOSl:TION OF DRAINS WOULD BE DETERMINED BY THE SOILS ENGINEER BASED UPON EXPOSED CONDITIONS. ------·------------- FILL OVER CUT DETAIL CUT/FILL CONTACT 1. AS SHOWN ON GRADING PLAN MAINTAIN MINIMUM .15" FILL SECTION FROM BACKCUT TO FACE OF FINISH SLOPE ,_ ________ __ 2. AS SHOWN ON AS· BUILT H ORIGINAL TOPOGRAPHY "'' l r~' '1fv' BEDROCK OR APPROVED MATERIAL 7J r )> -i m m G) I '-l LOWEST BENCH WIDTH 15' MINIMUM OR H/2 COMPACTED FILL NOTE: THE CUT PORTION OF THE SLOPE SHOULD BE EXCAVATED AND EVALUATED BY THE SOILS ENGINEER ANO/OR ENGINEERING GEOLOGIST PRIOR TO CONSTRUCTING THE FILL PORTION. ----· --·------------1111 - 7J r )> -I m m G) I CX) STABILIZATION Fl.LL FOR UNSTABLE MATERIAL EXPOSED I.N PORTION OF CUT SLOPE NAT.URAL SLOPE REMOVE: UNSTABLE MATEIJIAL ~ ~ t 15'.MINIMUM ,~~QSED FltllSHEP GRADE OR APPROVED MATERIAL REMOVE: UNSTABLE MATERIAL \\vii~~WiA:f ..:=IJ'MINIMUM TILTED BACK ' . . IF RECOMMENDED BY THE SOILS ENGINEER AND/OR ENGINEERING t4a,a--,.-W~ GEOLOGIST, THE REMAINING CUT PORTION OF THE SLOPE MAY I arf/ = REQUIRE REMOVAL AND REPLACEMENT WITH COMPACTED FILL -- NOTE: 1. SUBDRAINS ARE HOT REQUIRED UNLESS SPECIFIED BY SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST, . 2. ·wr SHALL BE EQUIPMENT WIDTH (15") FOR SLOPE HEIOHTS LESS THAN 25 FEET. FOR SLOPES GREATER· THAN 25 FEET ·w· SHALL BE DETERMINED BV THE PROJECT SOILS ENGINEER ANO /OR ENGINEERING GEOLOGIST. AT NO TIME SHALL •w• BE LESS THAN H/2. ---·---·-------------- -u ~ -I rn rn . Gl I lO SKIN FILL OF NATURAL GROUND ORIGINAL SLOPE 15" MINIMUM TO BE MAINTAINED FROM PROPOSED· FINISH SLOPE FAC·E TO BACKCUT - / ~~ · , ~ t J" Ml~IMUM KEY DEPTH ~ ...»"' .,J\ "m V#JWAA\vh{,Q:?jll~· --- NOTE: 1. THE NEED AND DISPOSITION OF DRAINS WILL BE DETERMINED! BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST BASED ON FIELO CONDITIONS. 2. PAD OVEREXCAVATION AND RECOMPACTION SHOULD BE PERFORMED IF DETERMINED TO BE NECESSARY BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST. --· ----·------------- -u r )> -I rn m G) I -Jo. 0 DAYLIGHT CUT LOT DETAIL ____,- RECONSTRUCT COMPACTED FILL SLOPE AT 2:1 OR FLATTER (MAY INCREASE OR DECREASE·PAD AREA). OVEREXCAVATE AND RECOMPACT --""" REPLACEMENT FILL AVOID AND/OR CLEAN UP SPILLAGE OF MATERIALS ON THE NATURAL SLOPE t ·t ! ~ NATURAL GRADE~ ~ / ~------ / NOTE: 1. SUBORAIN AND KEY .WIDTH REQUIREMENTS WILL BE DETERMINED BASED ON EXPOSED SUBSURFACE CONDITIONS AND THICKN~SS OF OVERBURDEN. 2. PAD OVER EXCAVATION AND RECOMPACTION SHOULD BE PERFORMED IF DETERMINED NECESSARY BY TH(i. SOILS ENGINEER AND/OR THE ENGINEERING GEOLOGIST. I I I I I I I I I I :I I I I I I I I I . TRANSITION LOT DETAIL CUT LOT (MATERIAL TYP.E TRANSITION) ------. --------·------------ ~ PAD GRADE TYPICAL BENCH ING CUT-FILL LOT (DA YUGHT TRANSITION) MUM PAD GRADE NOTE: * DEEPER OVEREXCAVATION MAY BE RECOMMENDED BY THE SOILS ENGINEER . ANO/OR ENGINEERING GEOLOGIST IN STEEP CUT-FILL TRANSITION AREAS. - PLATE EG-11" I I 1· I I- I I . I I I I I 1- I I I ·I I I SETTLEMENT PLATE AND RISER DETAIL 2"X 2'X 114• STEE·L PLATE STANDARD 3/4· PIPE NIPPLE WELDED TO TOP OF PLATE. ~---+--3/ 4 • X 5" GALVANIZED PIPE. STANDARD PIPE THREADS TOP AND.BOTTOM. EXTENSIONS THREADED ON BOTH ENDS AND ADDEO IN 5• INCREMENTS. 3 INCH SCHEDULE 40 PVC PIPE SLEEVE, ADD IN 5" INCREMENTS WITH GLU~ JOINTS • FINAL GRADE -! r. ! MAINTAIN 5' CLEARANCE OF HEAVY EQUIPMENT. --L+ ...L.A,,-MECHANICALLY HANO COMPACT IN 2"VERTICAL -r+ -r'\r LIFTS OR ALTERNATIVE SUITABLE TO AND L..__----:-.,. 111-__ _.,., ACCEPTED BY THE SOILS ENGINEER. 1 s· -~ s· I I I I 5• . I I . MECHANICALLY HAND COMPACT THE INITIAL s• VERTICA~ WITHIN A 5" RADIUS OF PLATE BASE. / / NOTE: I / / ' ' / ' . . . . . .. -. . . . .... .. . . . .. ' '• .. ·. . . . . . . .· . . .. ·-· . . . . . . . . . . . . ' ' "' BOTTOM OF CLEANOUT PROVIDE A MINIMUM 1• BEDDING OF COMPACTED SAND 1. LOCATIONS OF SETTLEMENT PLATES SHOULD BE CLEARLY MARKED ANO READILY VISIBLE (RED FLAGGED) TO EQUIPMENT OPERATORS. 2. CONTRACTOR SHOULD MAINTAIN CLEARANCE OF A S"RADIUS OF PLATE BASE ANO WITHIN 5' !VERTICAL) FOR HEAVY "EQUIPMENT. FILL WITHIN CLEARANCE AREA SHOULD BE HANO'COMPACTED TO PROJECT SPECIFICATIONS OR COMPACTED BY ALTERNATIVE APPROVED BY THE SOILS ENGINEER. 3. AFTER S'(VERTICALl OF F1LL IS IN PLACE, CONTRACTOR SHOULD MAINTAIN A 5.:RADIUS EQUIPMENT CLEARANCE FROM RISER. 4. PLACE ANO MECHANICALLY HAND COMPACT INITIAL 2' OF FILL PRIOR TO ESTABLISHING THE INITIAL READING. 5. IN THE EVENT OF DAMAGE TO THE SETTLEMENT PLATE OR EXTENSION RESULTING FROM EQUIPMENT OPERATING WITH IN THE SPECIFIED CLEARANCE AREA, CONTRACTOR SHOULD IMMEDIATELY NOTIFY THE SOILS ENGINEER ANO SHOULD BE RESPONSIBLE FOR RESTORING THE SETTLEMENT-P.t~l-E·S TO WORKING ORDER. 6. AN ALTERNATE DESIGN AND METHOD OF INSTALLATION MAY BE PROVIDED AT THE DISCRETION OF THE SOILS ENGINEER. PLATE EG-14 I I TYPICAL SURFACE SETTLEMENT MONUMENT I I I I I I I I. •I I I I I I I I I FlNISH GRADE ..___... 3/8.-DIAMETER X s• LENGTH CARRIAGE BOLT OR EQUIVALENT • DIAMETER X 3 112• LENGTH HOL:.E ,.._-+-CONCRETE BACKFILL .. ------".f.c,- PLATE EG-15 I I I I I ·1 I I I I I I I I I I I I ·I ~ TEST PIT SAFETY DIAGRAM 50 FEIT SPOIL P1LE SJOE VIEW { NOT TO SCALE ) TOP·VfE.W 100 FET t-w u. C, 1ft APPROXIMAlc; CEITER / CF TEST PIT . t-FLAG Hf u. C In 50 FEET --·-:-__ ..... --~_ l NOT TO SCALE ) -P_LATE EG-16 I I I I I I I I 1. I I I I I I ·I I I I OVERSIZE ROCK DISPOSAL VIEW NORMAL TO SLOPE FACE PROPOSED FINISH GRADE 1 O' MINIMUM (E) 0:::, . r:J:J 00 co ~ 151 MINIMUM (A) (BJ 00 ~ oO 201 MINIMUM D (GJ 00 c:o ~ cc oO oo(FJ ViEW PARALLEL TO SLOPE FACE PROPOSED FINISH GRADE 10' MINIMUM (E) 15• MINIMUM <::• Oot ~~~ ~ (GJ o:;,,::,o 15• MINIMUM ~~ffl~~~--.."t"'C-?;~~ I BEDROCK OR APPROVED MATERIAL NOTE: IA) ONE EQUIPMENT WIDTH OR A. MINIMUM OF 15 FEET. 18) HEIGHT ANO WIDTH MAY VA.RY DEPENDING ON ROCK SIZE AND TYPE OF EQUIPMENT. LENGTH OF WINDROW SHALL BE NO GREATER THAN 100· MAXIMUM. IC) IF APPROVED BY THE SOILS ENGINEER ANO/OR ENGINEERING GEOLOGIST, WINDROWS MAY BE PLACED DIRECTLY ON COMPETENT MATERIAL OR BEDROCK PROVIDED ADEQUATE SPACE IS AVAILABLE FOR COMPACTION. ~ IDl ORIENTATION OF WINDROWS MAY VARY BUT SHOULD BE AS RECOMMENDED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST. STAGGERING OF WINDROWS IS NOT NECESSARY UNLESS RECOMMENDED. . ~ (El CLEAR AREA FOR UTILITY TRENCHES, FOUNDATIONS AND SWIMMING POOLS. (Fl ALL FILL OYER AND AROUND ROCK WINDROW SHALL BE COMPACTED TO 90% RELATIVE COMPACTION OR AS RECOMMEND-ED. (GI AFTER FILL BETWEEN WINDROWS IS PLACED ANO COMPACTED WITH THE LIFT OF FILL COVERING WINDROW, WIN.DROW SHOULD BE PROOF ROLLED WITH A D-9 DOZER OR EQUIVALENT~ . VIEWS ARE DIAGRAMMATIC ONLY. ROO< SHOULD NOT TOUCH AND VOIDS SHOULD 8F COMPLETELY FILLED IN. PLATE RD-1 I I I I I I I I I I I I ·1 I I I I 'I I. ROCK DISPOSAL PITS VIEWS ARE OIAGRAMMA TIC ONLY. ROO< SHOULD NOT TOUCH ANO VOIDS SHOULD BE COMPLETELY FILLED IN, FILL LIFTS COMPACTED OVER ROCK AFTER EMBEDMENT r----------1 I I .--~ I 1 COMPACTED FILL I I I I GRANULAR MATERIAL ------, SIZE OF EXCAVATION TO BE COMMENSURATE WITH ROCK SIZE ROCK DISPOSAL LAYERS GRANULAR SOIL TO FILL VOIDS.~ . / COMPACTED FILL DENSIFIED BY FLOODING A---,------- LAYER ONE ROCK HIGH {10~{ --. -----------...... ------- PROFILE ALONG LAYER FILL SLOPE ICLEAR ZONE 20' MINIMUM LAYER ONE ROCK HIGH PLATE RD-2 . , ,.