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HomeMy WebLinkAboutCDP 03-49; Brown Family Trust Residence; Preliminary Geotechnical Investigation; 2004-03-02CoAs r GEOTECHNICAL c:().NSui.I'lNt; I-:N<;INI-;|';K^ A.NI) (fKoi.ocisTs April 15, 2002 Laverne and Elaine Brown 5411 Los Robles Drive Carlsbad, CA 92008 RE: PRELIMINARY GEOTECHNICAL INVESTIGATION Proposed Single Family Residence Lot 119, Map No. 3312 Vacant Lot, Carlsbad Boulevard APN 210-115-24 Carlsbad, CaUfornia Dear Mr. and Mrs. Brown: In response to your request and in accordance with our Proposal and Agreement dated March 14, 2002, we have performed a preliminary geotechnical investigation on the subject site for the proposed residence. The findings of the investigation, laboratory test results and recommendations for foundation design and site development are presented in this report. From a geologic and soils engineering point of view, it is our opinion that the site is suitable for the proposed development, provided the recommendations in this report are implemented during the design and construction phases. Ifyou have any questions, please do not hesitate to contact us at (858) 755-8622. This opportunity to be of service is appreciated. Respectfully submitted, COAST GEOTECHNiCAL Mark Burwell, C.E.G. Vithaya Singhanet, P.E. Engineering Geologist Geotechnical Engineer 779 ACADEMY DKIVK • SOIANA BEACH. CALIFORNIA 9207.^> CQP (858) 755-8,;2^ . FAX (8:^8^ 7^ 9:20 ^^^^ j^^^ ^ dZl' PRELIMINARY GEOTECHNICAL INVESTIGATION Proposed Single Family Residence Lot 119, Map No. 3312 Vacant Lot, Carlsbad Boulevard APN 210-115-24 Carlsbad, Califomia Prepared For: Laverne and Elaine Brown 5411 Los Robles Drive Carlsbad, CA 92008 April 15, 2002 W.O. P-357032 I I Prepared By: COAST GEOTECHNICAL 779 Academy Drive Solana Beach, Califomia 92075 TABLE OF CONTENTS VICINITY MAP INTRODUCTION 5 SITE CONDITIONS 5 PROPOSED ADDITION 5 SITE INVESTIGATION 6 LABORATORY TESTING 6 GEOLOGIC CONDITIONS 7 CONCLUSIONS 10 RECOMMENDATIONS 11 A. BUILDING PAD-REMOVALS/RECOMPACTION 11 B. TEMPORARY SLOPES/EXCAVATION CHARACTERISTICS 12 C. FOUNDATIONS 12 D. SLABS ON GRADE (INTERIOR AND EXTERIOR) 13 E. RETAINING WALLS 14 F. SETTLEMENT CFIARACTERISTICS 14 G. SEISMIC CONSIDERATIONS 14 H. SEISMIC DESIGN PARAMETERS 15 I. UTILITY TRENCH 15 J. DRAINAGE 16 K. GEOTECHNICAL OBSERVATIONS 16 L. PLAN REVIEW 17 LIMITATIONS 17 REFERENCES 19 APPENDICES APPENDIX A LABORATORY TEST RESULTS EXPLORATORY BORING LOGS GRADING PLAN APPENDIX B REGIONAL FAULT MAP SEISMIC DESIGN PARAMETERS DESIGN RESPONSE SPECTRUM APPENDIX C GRADING GUIDELINES Copyright © 2000 DeLortne. TopoXools Advanced Print Kit TE. Scale: 1 : 7,200 Zoom Level: 14-7 Datum: WGS84 Coast Geotechnical April 15, 2002 W.O. P-357032 Page 5 INTRODUCTION This report presents the results of our geotechnical investigation on the subject property. The purpose of this study is to evaluate the nature and characteristics of the earth materials underlying the property, the engineering properties of the surficial deposits and their influence on the proposed residence. SITE CONDITIONS The subject property is located just south of Cerezo Drive, along the east side of Carlsbad Boulevard, in the city of Carlsbad. The site includes a vacant rectangular lot that slopes very gently to the west. Relief on the site is approximately 3-0 vertical feet. The property is bounded along the north, south and east by developed residential lots. Vegetation includes a sparse to moderate gro-wth of ice plant, shrubs and cactus. Drainage is by sheet flow to the west. PROPOSED ADDITION PreUminary grading and building plans for development of the site were prepared by Grabhorn Engineering and DZN Partners Architecture, respectively. The project includes construction of a new two story residence over a proposed basement. Grading will include excavation up to 4.0 vertical feet for the basement. Coast Geotechnical April 15, 2002 W.O. P-357032 Page 6 SITE INVESTIGATION Site exploration included three (3) exploratory borings drilled to a maximum depth of 16.5 feet. Earth materials encountered were visually classified and logged by our field engineering geologist. Undisturbed, representative samples of earth materials were obtained at selected intervals. Samples were obtained by driving a thin walled steel sampler into the desired strata. The samples are retained in brass rings of 2.5 inches outside diameter and 1.0 inches in height. The central portion of the sample is retained in close fitting, waterproof containers and transported to our laboratory for testing and analysis. • LABORATORY TESTING Classification The field classification was verified through laboratory examination, in accordance with the Unified Soil Classification System. The final classification is shown on the enclosed Exploratory Logs. Moisture/Density The field moisture content and dry unit weight were determined for each of the undisturbed soil samples. This information is usefiil in providing a gross picture of the soil consistency or variation among exploratory excavations. The dry unit weight was determined in pounds per cubic foot. The field moisture content was determined as a Coast Geotechnical April 15, 2002 W.O. P-357032 Page 7 percentage of the dry unit weight. Both are shown on the enclosed Laboratory Tests Results and Exploratory Logs. Maximum Dry Density and Optimum Moisture Content The maximum dry density and optimum moisture content were determined for selected samples of earth materials taken from the site. The laboratory standard tests were in accordance with ASTM D-1557-91. The results of the tests are presented in the Laboratory Test Results. GEOLOGIC CONDITIONS The subject property is located in the Coastal Plains Physiographic Province of San Diego. The property is underlain at relatively shallow depths by Pleistocene terrace deposits. The terrace deposits are underlain at depth by Eocene-age sedimentary rocks which have commonly been designated as the Santiago Formation on published geologic maps. The terrace deposits are covered by thin residual soil deposits. A brief description of the earth materials encountered on the site follows. Artificial Fill No evidence of significant fill deposits were encountered in the exploratory borings. A small mound, approximately 2.0 feet high, of stockpiled sandy deposits with concrete fragments and roots was observed in the northeastem portion of the site. Coast Geotechnical April 15, 2002 W.O. P-357032 Page 8 Residual Soil Site exploration suggests the underlying terrace deposits are blanketed by approximately 3.0 to 6.0 inches of brown silty sand. The soil is generally dry and loose, as encountered in the exploratory borings. The contact with the underlying terrace deposits is gradational and may vary across the site. Terrace Deposits Underlying the surficial materials, poorly consoUdated Pleistocene terrace deposits are present. The sediments are composed of tan to reddish brown fine and medium-grained sand. The terrace deposits are dry to an approximate depth of 12 feet where a sUght increase in moisture was observed. Regionally, the Pleistocene sands are considered flat- lying and are underlain at depth by Eocene-age sedimentary rock units. Expansive Soil Based on our experience in the area and previous laboratory testing of selected samples, the residual soil and Pleistocene sands reflect an expansion potential in the low range. Ground Water No evidence of perched or high ground water tables were encountered to the depth explored. However, it should be noted that seepage problems can develop after completion of construction. These seepage problems most often result from drainage Coast Geotechnical April 15, 2002 W.O. P-357032 Page 9 alterations, landscaping and over-irrigation. In the event that seepage or saturated ground does occur, it has been our experience that they are most effectively handled on an individual basis. Tectonic Setting The site is located within the seismically active southern California region which is generally characterized by northwest trending Quaternary-age fault zones. Several of these fault zones and fault segments are classified as active by the California Division of Mines and Geology (Alquist-Priolo Earthquake Fault Zoning Act). Based on a review of pubUshed geologic maps, no known faults transverse the site. The nearest active fault is the offshore Rose Canyon Fault Zone located approximately 3-9 miles west of the site. It should be noted that the Rose Canyon Fault is not a continuous, well-defined feature but rather a zone of right stepping en echelon faults. The complex series of faults has been referred to as the Offshore Zone of Deformation (Woodward- Clyde, 1979) and is not fully understood. Several studies suggest that the Newport- Inglewood and the Rose Canyon faults are a continuous zone of en echelon faults (Treiman, 1984). Further smdies along the complex offshore zone of faulting may indicate a potentially greater seismic risk than current data suggests. Other faults which could affect the site include the Coronado Bank, Elsinore, San Jacinto and San Andreas Faults. The proximity of major faults to the site and site parameters are shown on the enclosed Seismic Design Parameters. Coast Geotechnical April 15, 2002 W.O. P-357032 Page 10 Liquefaction Potential Liquefaction is a process by which a sand mass loses its shearing strength completely and flows. The temporary transformation of the material into a fluid mass is often associated with ground motion resulting from an earthquake. Owing to the moderately dense nature of the Pleistocene terrace deposits and the anticipated depth to ground water, the potential for seismically induced liquefaction and soil instabiUty is considered low. CONCLUSIONS 1) The subject property is located approximately 300 lateral feet east of the coastal bluffs and is relatively free of potential geologic hazards such as landsliding, liquefaction, high ground water conditions and seismically induced subsidence. 2) The existing soil and dry terrace deposits are not suitable for the support of proposed footings and concrete flatwork in their present condition. These surficial deposits should be removed in the upper 3 0 feet and replaced as properly compacted fill deposits in areas which will support footings and concrete flatwork outside the proposed basement walls. 3) It is anticipated that the basement excavation will expose terrace deposits. Coast Geotechnical April 15, 2002 W.O. P-357032 Page 11 However, if dry and loose materials are encountered in the area of the proposed basement slab they should be compacted. All retaining wall footings should be founded the design depth into competent terrace deposits. RECOMMENDATIONS Building Pad-Removals/Recompaction In foundation and slab areas outside the proposed basement walls, the existing soil and weathered terrace deposits should be removed to a minimum depth of 3.0 feet belowthe existing grade or 18 inches below the base of proposed footings, whichever is greater, and replaced as properly compacted fill. Removals should include the entire building pad extending a minimum of 5.0 feet beyond the building footprint, where applicable. Most of the existing earth deposits are generally suitable for reuse, provided they are cleared of all vegetation, debris and thoroughly mixed. Prior to placement of fill, the base of the removal should be observed by a representative of this firm. Additional overexcavation and recommendations may be necessary at that time. The exposed bottom should be scarified to a minimum depth of 6.0 inches, moistened as required and compacted to a minimum of 90 percent of the laboratory maximum dry density. Fill should be placed in 6.0 to 8.0 inch lifts, moistened to approximately 1.0 - 2.0 percent above optimum moisture content and compacted to a minimum of 90 percent of the laboratory maximum dry density. Soil and weathered terrace deposits in areas of proposed concrete flatwork and driveways should be removed and replaced as properly Coast Geotechnical April 15, 2002 W.O. P-357032 Page 12 compacted fill. Imported fill, if necessary, should consist of non-expansive granular deposits approved by the geotechnical engineer. Temporary Slopes/Excavation Characteristics Temporary excavations should be trimmed to a gradient of V2:l (horizontal to vertical) or less depending upon conditions encountered during grading. The Pleistocene Terrace deposits may contain hard concretion layers. However, based on our experience in the area, the sandstone is rippable with conventional heavy earth moving equipment in good working order. Foundations The following design parameters are based on footings founded into non-expansive approved compacted fill deposits or competent terrace deposits. Footings for the proposed residence and garage should be a minimum of 12 inches wide and founded a minimum of 12 inches and 18 inches below the lower most adjacent subgrade at the time of foundation construction for single-story and two-story structures, respectively. A 12 inch by 12 inch grade beam should be placed across the garage opening. Footings should be reinforced in accordance with the project structural engineer's recommendations. Footing and slab recommendations provided herein are based upon underlying soil conditions and are not intended to be in lieu of the project structural engineer's design. Coast Geotechnical April 15, 2002 W.O. P-357032 Page 13 For design purposes, an allowable bearing value of 1500 pounds per square foot may be used for foundations at the recommended footing depths. The bearing value may be increased to 2000 pounds per square foot for subterranean retaining wall footings. The bearing value indicated above is for the total dead and frequently applied live loads. This value may be increased by 33 percent for short durations of loading, including the effects of wind and seismic forces. Resistance to lateral load may be provided by friction acting at the base of foundations and by passive earth pressure. A coefficient of friction of 0.35 may be used with dead- load forces. A passive earth pressure of 250 pounds per square foot, per foot of depth of fill penetrated to a maximum of 1500 pounds per square foot may be used. Slabs on Grade (Interior and Exterior) Slabs on grade should be a minimum of 4.0 inches thick and reinforced in both directions with No. 3 bars placed 18 inches on center in both directions. The slab should be underlain by a minimum 2.0-inch sand blanket. Where moisture sensitive floors are used, a minimum 6.0-mil Visqueen or equivalent moisture barrier should be placed over the sand blanket and covered by an additional two inches of sand. Utility trenches underlying the slab may be backfilled with on-site materials, compacted to a minimum of 90 percent of the laboratory maximum dry density. Slabs including exterior concrete flatwork should be reinforced as indicated above and provided with saw cuts/expansion Coast Geotechnical April 15, 2002 W.O. P-357032 Page 14 joints, as recommended by the project structural engineer. Ml slabs should be cast over dense compacted subgrades. Retaining Walls Cantilever walls (yielding) retaining nonexpansive granular soils may be designed for an active-equivalent fluid pressure of 35 pounds per cubic foot. Restrained walls (nonyielding) should be designed for an "at-rest" equivalent fluid pressure of 58 pounds per cubic foot. Wall footings should be designed in accordance with the foundation design recommendations. All retaining walls should be provided with an adequate backdrainage system (Miradrain 6000 or equivalent is suggested). The soil parameters assume a level granular backfill compacted to a minimum of 90 percent of the laboratory maximum dry density. Settlement Characteristics Estimated total and differential settlement is expected to be on the order of 3/4 inch and 1/2 inch, respectively. It should also be noted that long term secondary settlement due to irrigation and loads imposed by structures is anticipated to be 1/4 inch. Seismic Considerations Although the UkeUhood of ground rupture on the site is remote, the property wiU be exposed to moderate to high levels of ground motion resulting from the release of energy Coast Geotechnical April 15, 2002 W.O. P-357032 Page 15 should an earthquake occur along the numerous known and unknown faults in the region. The Rose Canyon Fault Zone is the nearest known active fault and is considered the design earthquake for the site. A maximum probable event along the offshore segment of the Rose Canyon Fault is expected to produce a peak bedrock horizontal acceleration of 0.39g and a repeatable ground acceleration of 0.25g. Seismic Design Parameters (1997 Uniform Building Code^ Soil Profile Type - S, Seismic Zone - 4 Seismic Source - Type B Near Source Factor (N,) - 1.1 Near source Acceleration Factor (NJ - 1.0 Seismic Coefficients C, = 0.40 C, = 0.64 Design Response Spectrum T, = 0.643 T„ = 0.129 Utility Trench We recommend that all utilities be bedded in clean sand to at least one foot above the top of the conduit. The bedding should be flooded in place to fiU all the voids around the conduit. Imported or on-site granular material compacted to at least 90 percent relative compaction may be utilized for backfiU above the bedding. Coast Geotechnical April 15, 2002 W.O. P-357032 Page 16 The invert of subsurface utility excavations paralleling footings should be located above the zone of influence of these adjacent footings. This zone of influence is defined as the area below a 45 degree plane projected down from the nearest bottom edge of an adjacent footing. This can be accomplished by either deepening the footing, raising the invert elevation of the utility, or moving the utility or the footing away from one another. Drainage Specific drainage patterns should be designed by the project engineer. However, in general, pad water should be directed away from foundations and around the structure to the street. Roof water should be collected and conducted to hardscape or the street, via non-erodible devices. Pad water should not be allowed to pond. Vegetation adjacent to foundations should be avoided. If vegetation in these areas is desired, sealed planter boxes or drought resistant plants should be considered. Other alternatives may be available, however, the intent is to reduce moisture from migrating into foundation subsoils. Irrigation should be limited to that amount necessary to sustain plant Ufe. All drainage systems should be inspected and cleaned annually, prior to winter rains. Geotechnical Observations Structural footing excavations should be observed by a representative of this firm, prior to the placement of steel and forms. All fiU should be placed while a representative of the geotechnical engineer is present to observe and test. Coast Geotechnical April 15, 2002 W.O. P-357032 Page 18 Please note that fluctuations in the level of ground water may occur due to variations in rainfall, temperature and other factors not evident at the time measurements were made and reported herein. Coast Geotechnical assumes no responsibility for variations which may occur across the site. The conclusions and recommendations of this report apply as of the current date. In time, however, changes can occur on a property whether caused by acts of man or nature on this or adjoining properties. Additionally, changes in professional standards may be brought about by legislation or the expansion of knowledge. Consequently, the conclusions and recommendations of this report may be rendered wholly or partially invalid by events beyond our control. This report is therefore subject to review and should not be relied upon after the passage of two years. The professional judgments presented herein are founded partly on our assessment of the technical data gathered, partly on our understanding of the proposed construction and partly on our general experience in the geotechnical field. However, in no respect do we guarantee the outcome of the project. APPENDIX A LABORATORY TEST RESULTS TABLE I Maximum Dry Density and Optimum Moisture Content (Laboratory Standard ASTM D-1557-91) Sample Max. Dry Optimum Location Density Moisture Content (pcf) B-1 @ 1.0'-3.0' 128 . 6 10 .1 TABLE II Field Dry Density and Moisture Content Sample Field Dry Field Moisture Location Density Content (pcf) % B-1 @ 1.0' 109 . 1 3 . 6 B-1 @ 2.0' 96 . 4 3 . 3 B-1 @ 3.5' 94 . 1 4 .1 B-1 ©8.0' 105 .4 4.4 B-1 @ 11.0' 112 . 2 6 . 6 B-1 @ 15.0' Sample Disturbed 7.1 B-2 @ 2.5' 96 .1 3.4 B-2 @ 3.5' 104 . 8 3.5 B-2 @ 7.0' 107 .1 3.2 B-2 @ 9.0' Sample Disturbed 4 . 5 B-3 @ 2.0' 94 .1 3.4 B-3 @ 5.0' Sample Disturbed 4 . 6 B-3 @ 7.0' Sample Disturbed 4 . 5 P-357032 LOG OF EXPLORATORY BORING NO. 1 DRILL RIG: PORTABLE BUCKET AUGER BORING DIAMETER: 3.5" SURFACE ELEV: 51.5" u a. >^ H t-H Q >H Pi Q 109.1 96.4 94.1 105.4 112.2 w H i 3.6 3.3 4.1 4.4 6.6 7.1 w H I H w W H W Q : I — 2.00 T3 t (U o I. •a o o 51.50 0.00 49.50 • IIKtlMl « N X I 47 I r jir ir ^' M H 4.C< , V » pilKl Md iiiMYiHa ffiinmsl 6.01 43. 8.0 f it it pilMIIM^ I I 41. 10.00 39.' 12.1 X it Kl H I IttX « X X9 fiiiTiiiiri |C IN XI MIIHIIKI 37..'iO 14.00 35..^0 16.00 n Ml xd VI O c/3 IZl U d o SM SM PROJECTNO. P-357032 DATE DRILLED: 03-29-02 LOGGED BY: MB GEOLOGIC DESCRIPTION SOIL(Qs): Bm.silty and fine-grained sand, dry, loose TERRACE DEPOSITS (Qt): Tan to Reddish bm., fine and med.-grained sand, dry, dense From 12', increase in moisture End of Boring @ 16.5' SHEET 1 OF 1 COAST GEOTECHNICAL LOG OF EXPLORATORY BORING NO. 2 DRILL RIG: PORTABLE BUCKET AUGER BORING DIAMETER: 3.5" SURFACE ELEV.: 52' PROJECT NO. P-357032 DATE DRILLED: 03-29-02 LOGGED BY: MB o o. >^ H w Q Q 96.1 104.8 107.1 w H i 3.4 3.5 3.2 4.5 Pi I w o < 1.00 — 50.00 (U t <u O l-l 0) -o o 6 o I I 2.00 — 49.00 I 1 $ w ffi H OH s 52.00 — 0.00 51.00 3.00 48.00 Sr.=.«"- 4.00 47.00 rrrSi' r%' isiK lacr fiVAii'iVs IHH IMi 5.00 46.00 6.00 45.00 — 7.00 44.00 g 00 iiiKiiiri — 9.00 •fimm IIMtSKI 43.00 i ar- tSIHIIM! iKxr— :*:%':%' iiNiixr U c/3 c/3 C« c/3 SM SM GEOLOGIC DESCRIPTION SOIL (Qs): Bm.silty and fine-grained sand, dry, loose TERRACE DEPOSITS (Qt): Tan to Reddish bm., fine and med.-grained sand, dry, dense EndofBoring@9.5' SHEET 1 OF 1 COAST GEOTECHNICAL LOG OF EXPLORATORY BORING NO. 3 DRILL RIG: PORTABLE BUCKET AUGER BORING DIAMETER: 3.5" SURFACE ELEV.: 52.5' H ai Q H [/3 i ai w H I w u <: g w ffi H W Q 52.50 (A O C/3 V—' c/3 C/3 o PROJECT NO. P-357032 DATE DRILLED: 03-29-02 LOGGED BY: MB GEOLOGIC DESCRIPTION 94.1 3.4 I 1.00 — 50.50 4.6 -o a </] O l-l T3 O o 2.00 — 49.50 I 4.5 I — 0.00 51.50 IIIHtlML KSKVIHI 1^ riYifiViVi' 3.00 48.50 EIIMtIK: E33K»N1 riiL IXtXtSL. 4.00 47.50 5.00 46.50 — 6.00 45.50 — 7.00 44.50 8.00 43.50 SHEET I OF I SM SM iiiiitlia' rrflQRR IIIM IIM I J.VAW.V fiYiiiKiii liXitSCi lYiTiViri' IlIHIIML riiH'igxr SOIL (Qs): Bm.silty and fine-grained sand, dry, loose TERRACE DEPOSITS (Qt): Tan to Reddish bm., fine and med.-grained sand, dry, dense End of Boring @ 9' COAST GEOTECHNICAL < > u .J 9 O « < ffi < l.^^-^'^l Z'i+QO +/- PER OWG NO J31-7 \ [50.68] PER DWG NO 331-7 PORTION OF GRADING PLAN LEGEND 4- BORING LOCATION (approx ) 1. COAST GEOTECHNICAL P-357032 GRAPHIC SCALE APPENDIX B CALIFORNIA FAULT MAP BROWN 1100 1000 -- 900 -- 800 700 600 -- 500 200 100 -100 400 -- 300 -400 -300 -200 -100 100 200 300 400 500 600 *********************** * * * UBCSEIS * * * * Version 1.03 * + * ************************ COMPUTATION OF 1997 UNIFORM BUILDING CODE SEISMIC DESIGN PARAMETERS JOB NUMBER: P-357032 JOB NAME: BROWN FAULT-DATA-FILE NAME: CDMGUBCR.DAT DATE: 04-12-2002 SITE COORDINATES: SITE LATITUDE; 33.1284 SITE LONGITUDE: 117.3323 UBC SEISMIC ZONE: 0,4 UBC SOIL PROFILE TYPE: SC NEAREST TYPE A FAULT: NAME: ELSINORE-JULIAN DISTANCE: 40.6 km NEAREST TYPE B FAULT: NAME: ROSE CANYON DISTANCE: 6.3 km NEAREST TYPE C FAULT: NAME: DISTANCE: 99999.0 km SELECTED UBC SEISMIC COEFFICIENTS: Na: 1.0 Nv: 1.1 Ca: 0.40 Cv: 0.64 Ts: 0.643 To: 0.129 SUMMARY OF FAULT PARAMETERS Page 1 APPROX, SOURCE 1 MAX, 1 SLIP 1 FAULT ABBREVIATED 1 DISTANCE TYPE 1 MAG, 1 RATE 1 TYPE FAULT NAME 1 (km) (A,B,C) 1 (Mw) 1 (mm/yr) 1(SS,DS,BT) ROSE CANYON 1 6,3 B 1 6,9 1 1,50 1 SS NEWPORT-INGLEWOOD (Offshore) 1 9.5 B 1 6.9 i 1,50 1 SS CORONADO BANK 1 32.2 B 1 7.4 1 3,00 1 ss ELSINORE-TEMECULA 1 40.5 B i 6,8 1 5,00 1 SS ELSINORE-JULIAN 1 40,6 A 1 7,1 1 5,00 1 ss ELSINORE-GLEN IVY 1 57,2 B 1 6,8 1 5,00 1 ss PALOS VERDES 1 58,9 B 1 7,1 1 3,00 1 ss EARTHQUAKE VALLEY 1 70,2 B 1 6,5 1 2,00 1 ss NEWPORT-INGLEWOOD (L.A.Basin) 1 76,4 B 1 6,9 1 1.00 1 ss SAN JACINTO-ANZA 1 77.1 A 1 7,2 1 12,00 1 ss SAN JACINTO-SAN JACINTO VALLEY 1 78,2 B ! 6,9 1 12,00 1 ss CHINO-CENTRAL AVE. (Elsinore) 1 79,3 B 1 6,7 1 1,00 1 DS SAN JACINTO-COYOTE CREEK 1 85,0 B 1 6,8 1 4,00 1 ss ELSINORE-WHITTIER 1 85,5 B 6,8 1 2,50 1 ss ELSINORE-COYOTE MOUNTAIN 1 92.2 B 6.8 1 4,00 1 ss SAN JACINTO-SAN BERNARDINO 1 99,1 B 6,7 1 12,00 1 ss SAN JACINTO - BORREGO 1 106,3 B 6,6 1 4.00 1 ss SAN 7\NDREAS - Southern 1 106,8 A 7.4 1 24.00 1 ss SAN JOSE 1 112.6 B 6,5 1 0,50 1 DS CUCAMONGA 1 116.8 A 7,0 1 5,00 1 DS SIERRA MADRE (Central) 1 116,9 B 7,0 1 3,00 1 DS PINTO MOUNTAIN 1 117,9 B 7.0 1 2,50 1 SS NORTH FRONTAL FAULT ZONE (West) 1 125,6 B 7.0 1 1,00 1 DS BURNT MTN, 1 127,2 B 6.5 1 0.60 1 SS CLEGHORN 1 127,6 B 6,5 1 3,00 1 SS RAYMOND 1 131,4 B 6,5 1 0,50 1 DS EUREKA PEAK 1 131.6 B 6,5 1 0,60 1 SS CLAMSHELL-SAWPIT 1 132,0 B 6,5 1 0,50 1 DS SUPERSTITION MTN. (San Jacinto) 1 132,2 B 6.6 1 5,00 1 SS SAN ANDREAS - 1857 Rupture 1 132,7 A 7,8 1 34,00 1 SS NORTH FRONTAL FAULT ZONE (East) 1 133,6 B 6,7 1 0,50 DS VERDUGO 1 135.2 B 6,7 1 0,50 DS ELMORE RANCH 1 138,1 B 6,6 1 1, 00 SS HOLLYWOOD 1 138,3 1 B 6.5 1 1,00 DS SUPERSTITION HILLS (San Jacinto) 1 139,7 1 B 6,6 1 4.00 SS ELSINORE-LAGUNA SALADA 1 142,3 1 B 7,0 1 3,50 SS LANDERS 1 143,2 1 B 7,3 0,60 SS HELENDALE - S, LOCKHARDT 1 144,7 1 B 7,1 0,60 SS SANTA MONICA 1 145,9 1 B 6,6 1,00 DS MALIBU COAST 1 150,2 1 B 6,7 0,30 DS LENWOOD-LOCKHART-OLD WOMAN SPRGS 1 150,9 i B 7,3 0,60 SS BRAWLEY SEISMIC ZONE 1 153,3 1 B 6,5 25,00 SS JOHNSON VALLEY (Northern) 1 155.9 1 B 6.7 0.60 SS SIERRA MADRE (San Fernando) 1 156,1 1 B 6.7 2.00 DS EMERSON So, - COPPER MTN, 1 156,3 1 B 6,9 0,60 SS ANACAPA-DUME 1 158.6 1 B 7,3 3,00 DS SUMMARY OF FAULT PARAMETERS Page APPROX. SOURCE MAX, SLIP FAULT ABBREVIATED DISTANCE TYPE MAG, RATE TYPE FAULT NAME (km) (A,B,C) (Mw) (mm/yr) 1(SS,DS,BT) ================================== ======== ======= ====== ========= ==:===== SAN GABRIEL 159,0 B 7,0 1,00 SS IMPERIAL 165,9 A 7,0 20,00 ss PISGAH-BULLION MTN,-MESQUITE LK 166,5 B 7,1 0. 60 SS CALICO - HIDALGO 169,2 B 7,1 0,60 ss SANTA SUSANA 171,5 B 6,6 5.00 DS HOLSER 180,4 B 6,5 0.40 DS SIMI-SANTA ROSA 187,9 B 6,7 1.00 DS OAK RIDGE (Onshore) 188,7 B 6,9 4.00 DS SAN CAYETANO 197,2 B 6,8 6. 00 DS GRAVEL HILLS - HARPER LAKE 197.7 B 6,9 0, 60 SS BLACKWATER 212,8 B 6,9 0,60 SS VENTURA - PITAS POINT 216,1 B 6,8 1.00 DS SANTA YNEZ (East) 216,9 B 7,0 2,00 SS SANTA CRUZ ISLAND 224,7 B 6.8 1,00 DS M, RIDGE-ARROYO PARIDA-SANTA ANA 1 226,7 B 6,7 0,40 DS RED MOUNTAIN 1 230,1 B 6,8 2.00 DS GARLOCK (West) 1 233,4 A 7.1 6. 00 SS PLEITO THRUST 1 238.6 B 6,8 2,00 I DS BIG PINE 1 244,4 B 6,7 0. 80 i SS GARLOCK (East) 1 248,3 A 7,3 7,00 1 ss WHITE WOLF 1 259,3 1 B 7.2 2,00 1 DS SANTA ROSA ISLAND 1 259,6 1 B 6,9 1,00 1 DS SANTA YNEZ (West) 1 262,0 1 B 1 6,9 2.00 1 SS So, SIERRA NEVADA 1 272,7 1 B 1 7,1 1 0.10 1 DS LITTLE LAKE 1 277,5 1 B 1 6,7 0.70 1 SS OWL LAKE 1 278,8 1 B 1 6.5 1 2.00 1 SS PANAMINT VALLEY 1 279,0 1 B 1 7.2 1 2.50 1 ss TANK CANYON 1 279,6 1 B 1 6,5 1 1.00 1 DS DEATH VALLEY (South) 1 288.2 1 B 1 6,9 1 4.00 1 SS LOS ALAMOS-W, BASELINE 1 304,2 1 B 1 6.8 1 0.70 1 DS LIONS HEAD 1 321.7 1 B 1 6.6 1 0.02 1 DS DEATH VALLEY (Graben) 1 329,1 1 B 1 6,9 1 4.00 1 DS SAN LUIS RANGE (S. Margin) 1 331,4 1 B 1 7,0 1 0.20 1 DS SAN JUAN 1 332.1 1 B 1 7,0 1 1.00 1 SS CASMALIA (Orcutt Frontal Fault) 1 339.8 1 B 1 6,5 1 0,25 1 DS OWENS VALLEY 1 345,9 1 B 1 7,6 1 1,50 1 SS LOS OSOS 1 361,5 1 B 1 6.8 1 0,50 1 DS HOSGRI 1 367,5 1 B 1 7,3 1 2.50 1 SS HUNTER MTN. - SALINE VALLEY 1 372,5 1 B 1 7,0 1 2.50 1 SS INDEPENDENCE 1 381,7 1 B 1 6,9 1 0.20 1 DS DEATH VALLEY (Northern) 1 382,4 1 A 1 7,2 1 5,00 1 SS RINCONADA 1 382.4 1 B 1 7,3 1 1,00 1 SS BIRCH CREEK 1 438,0 1 B 1 6,5 1 0.70 1 DS SAN ANDREAS (Creeping) 1 438,7 1 B 1 5,0 1 34.00 1 SS WHITE MOUNTAINS 1 442.6 1 B 1 7,1 1 1,00 1 SS DEEP SPRINGS 1 461,1 1 B 1 6,6 1 0.80 1 DS c o 0 0 o o < o 0 Q. CO DESIGN RESPONSE SPECTRUM Seismic Zone: 0.4 Soil Profile: SC 2.5 2.0 1.5 1.0 0.5 0.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Period Seconds APPENDIX C GRADING GUIDELINES Grading shouid be performed to at least tlie minimum requirements of the governing agencies, Chapter 33 of the Uniform Building Code, the geotechnical report and the guidelines presented below. All of the guidelines may not apply to a specific site and additional recommendations may be necessary during the grading phase. Site Clearing Trees, dense vegetation, and other deleterious materials should be removed from the site. Non-organic debris or concrete may be placed in deeper fill areas under direction of the Soils engineer. Subdrainage 1. During grading, the Geologist and Soils Engineer should evaluate the necessity of placing additional drains (see Plate A). 2. All subdrainage systems should be observed by the Geologist and Soils Engineer during construction and prior to covering with compacted fill. 3. Consideration should be given to having subdrains located by the project surveyors. Outlets should be located and protected. Treatment of Existing Ground 1. All heavy vegetation, rubbish and other deleterious materials should be disposed of off site. 2. All surficial deposits including alluvium and colluvium should be removed unless otherwise indicated in the text of this report. Groundwater existing in the alluvial areas may make excavation difficult. Deeper removals than indicated in the text of the report may be necessary due to saturation during winter months. 3. Subsequent to removals, the natural ground should be processed to a depth of six inches, moistened to near optimum moisture conditions and compacted to fill standards. Fill Placement 1. Most site soil and bedrock may be reused for compacted fill; however, some special processing or handling may be required (see report). Highly organic or contaminated soil should not be used for compacted fill. (1) 2. Material used in the compacting process should be evenly spread, moisture conditioned, processed, and compacted in thin lifts not to exceed six inches in thickness to obtain a uniformly dense layer. The fill should be placed and compacted on a horizontal plane, unless othenA/ise found acceptable by the Soils Engineer. 3. If the moisture content or relative density varies from that acceptable to the Soils engineer, the Contractor should rework the fill until it is in accordance with the following: a) Moisture content of the fill should be at or above optimum moisture. Moisture should be evenly distributed without wet and dry pockets. Pre- watering of cut or removal areas should be considered in addition to watering during fill placement, particularly in clay or dry surficial soils. b) Each six inch layer should be compacted to at least 90 percent of the maximum density in compliance with the testing method specified by the controlling governmental agency. In this case, the testing method is ASTM Test Designation D-1557-91. 4. Side-hill fills should have a minimum equipment-width key at their toe excavated through all surficial soil and into competent material (see report) and tilted back into the hill (Plate A). As the fill is elevated, it should be benched through surficial deposits and into competent bedrock or other material deemed suitable by the Soils Engineer. 5. Rock fragments less than six inches in diameter may be utilized in the fill, provided: a) They are not placed in concentrated pockets; b) There is a sufficient percentage of fine-grained material to surround the rocks; c) The distribution of the rocks is supervised by the Soils Engineer. 6. Rocks greater than six inches in diameter should be taken off site, or placed in accordance with the recommendations of the Soils Engineer in areas designated as suitable for rock disposal. 7. In clay soil large chunks or blocks are common; if in excess of six (6) inches minimum dimension then they are considered as oversized. Sheepsfoot compactors or other suitable methods should be used to break the up blocks. (2) 8. The Contractor should be required to obtain a minimum relative compaction of 90 percent out to the finished slope face of fill slopes. This may be achieved by either overbuilding the slope and cutting back to the compacted core, or by direct compaction of the slope face with suitable equipment. If fill slopes are built "at grade" using direct compaction methods then the slope construction should be performed so that a constant gradient is maintained throughout construction. Soil should not be "spilled" over the slope face nor should slopes be "pushed out" to obtain grades. Compaction equipment should compact each lift along the immediate top of slope. Slopes should be back rolled approximately every 4 feet vertically as the slope is built. Density tests should be taken periodically during grading on the flat surface of the fill three to five feet horizontally from the face of the slope. In addition, if a method other than over building and cutting back to the compacted core is to be employed, slope compaction testing during construction should include testing the outer six inches to three feet in the slope face to determine if the required compaction is being achieved. Finish grade testing of the slope should be performed after construction is complete. Each day the Contractor should receive a copy ofthe Soils Engineer's "Daily Field Engineering Report" which would indicate the results of field density tests that day. 9. Fill over cut slopes should be constructed in the following manner: a) All surficial soils and weathered rock materials should be removed at the cut-fill interface. b) A key at least 1 equipment width wide (see report) and tipped at least 1 foot into slope should be excavated into competent materials and observed by the Soils Engineer or his representative. c) The cut portion of the slope should be constructed prior to fill placement to evaluate if stabilization is necessary, the contractor should be responsible for any additional earthwork created by placing fill prior to cut excavation. 10. Transition lots (cut and fill) and lots above stabilization fills should be capped with a four foot thick compacted fill blanket (or as indicated in the report). 11. Cut pads should be observed by the Geologist to evaluate the need for overexcavation and replacement with fill. This may be necessary to reduce water infiltration into highly fractured bedrock or other permeable zones,and/or due to differing expansive potential of materials beneath a structure. The overexcavation should be at least three feet. Deeper overexcavation may be recommended in some cases. (3) 12. Exploratory backhoe or dozer trenches still remaining after site removal should be excavated and filled with compacted fill if they can be located. Grading Observation and Testinq 1. Observation of the fill placement should be provided by the Soils Engineer during the progress of grading. 2. In general, density tests would be made at intervals not exceeding two feet of fill height or every 1,000 cubic yards of fill placed. This criteria will vary depending on soil conditions and the size of the fill. In any event, an adequate number of field density tests should be made to evaluate if the required compaction and moisture content is generally being obtained. 3. Density tests may be made on the surface material to receive fill, as required by the Soils Engineer. 4. Cleanouts, processed ground to receive fill, key excavations,subdrains and rock disposal should be observed by the Soils Engineer prior to placing any fill. It will be the Contractor's responsibility to notify the Soils Engineer when such areas are ready for observation. 5. A Geologist should observe subdrain construction. 6. A Geologist should observe benching prior to and during placement of fill. Utility Trench Backfill Utility trench backfill should be placed to the following standards: 1. Ninety percent of the laboratory standard if native material is used as backfill. 2. As an alternative, clean sand may be utilized and flooded into place. No specific relative compaction would be required; however, observation, probing, and if deemed necessary, testing may be required. 3. Exterior trenches, paralleling a footing and extending below a 1:1 plane projected from the outside bottom edge of the footing, should be compacted to 90 percent of the laboratory standard. Sand backfill, unless it is similar to the inplace fill, should not be allowed in these trench backfill areas. Density testing along with probing should be accomplished to verify the desired results. (4)