Loading...
HomeMy WebLinkAbout; ; PRELIMINARY GEOTECHNICAL INVESTIGATION; TWO PROPOSED WATER STORAGE TANKS SOUTH OF PALOMAR AIRPORT ROAD BETWEEN I-5 AND EL CAMINO REAL; 1990-10-02- ... ... ... ... ... ... ... .. ... ... ... ... .. ... -... -... ... ... ... .. ... ... -.. .. ... .. ... -... LEIGHTON AND ASSOCIATES, INC Geotechnical and Environmental Engineering Consuhants PRELIMINARY GEOTECHNICAL INVESTIGATION, TWO PROPOSED ±8.2 MILLION GALLON WATER STORAGE TANKS, LOCATED SOUTH OF PALOMAR AIRPORT ROAD BETWEEN INTERSTATE 5 AND EL CAMINO REAL, CARLSBAD, CALIFORNIA October 2, 1990 Project No. 8900881-01 Prepared For: MACDONALD-STEPHENS ENGINEERS, INC . 11770 Bernardo Plaza Court, Suite 212 San Diego, California 92128 5421 AVENI DA ENCINAS, SUITE C, CARLSBAD, CALIFORNIA 9200B (619) 931-9953 fAX ( 619) 931-9326 ... ... ... ... ... ... .. ... .. ""' ... .. -.. -... ... ... ... ... .. .. ... .. -... -... -... .. .. --... ... -.. To: Attention: LEIGHTON AND ASSOCIATES, INC • Geotechnical and Environmental Engineering Consultants October 2, 1990 MacDonald-Stephens Engineers, Inc. 11770 Bernardo Plaza Court, Suite 212 San Diego, California 92128 Mr. Robert Coates Project No. 8900881-01 Subject: Preliminary Geotechnical Investigation, Two Proposed ±8.2 Million Ga 11 on Water Storage Tanks Located South of Palomar Airport Road Between Interstate 5 and El Camino Real, Carlsbad, California Introduction In accordance with your request, we have performed a preliminary geotechnical investigation of the subject property. The accompanying report presents a summary of our investigation and provides conclusions and recommendations relative to site development . If you have any questions regarding our report, please do not hesitate to contact this office. We appreciate this opportunity to be of service . WM/MRS/SRH/bje Distribution: (3) Addressee Respectfully submitted, LEIGHTON AND ASSOCIATES, INC . ~~~ Michael R. Stewart, CEG 1349 (Exp. 6/30/92) Chief Geologist -2~~~;.~ Stan Helenschmidt, GE 2064 (Exp. 6/30/92) Chief Engineer/Manager 5421 AVENIDA ENCINAS, SUITE C, CARLSBAD, CALIFORNIA 92008 (619) 931-9953 FAX (619) 931-9326 .. .. ... .. ... .. ... .. ... .. ... -.. ... ... ... .. ... .. .. ... ... ... -... -... - ... ... .. ... -... .. ... TABLE OF CONTENTS Section 1.0 INTRODUCTION 2.0 SITE DESCRIPTION AND PROPOSED DEVELOPMENT 3.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING 4.0 GEOTECHNICAL CONDITIONS 4.1 Regional Geology 4.2 Site Geology .. 4.3 Ground Water .. 5.0 FAULTING AND SEISMICITY 5.1 Faulting .. . 5.2 Seismicity .. . 5.2.1 Lurching and Shallow Ground Rupture 5.2.2 Liquefaction and Dynamic Settlement 6.0 CONCLUSIONS 7.0 RECOMMENDATIONS 7.1 Earthwork 7.1.1 Site Preparation 7.1.2 Excavations . . . ..... 7.1.3 Trench Excavations and Backfill 7:1.4 Fills . . . . . . . ... 7.1.5 Overexcavation of Daylight Building Pads 7.2 Foundation Design ............. . 7.3 Lateral Earth Pressure and Lateral Resistance 7.4 Settlment Considerations 7.5 Surface Drainage and Erosion 7.6 Construction Observation -i - 8900881-01 Page 1 1 3 4 4 4 4 5 5 5 8 8 9 10 10 10 10 10 10 11 11 11 12 12 13 LEIGHTON AND ASSOCIATES, INC. --... -... -.. -... -.. -... -.. .. ... -.. -.. -.. ... .. ... ... -... ... ... ... ... ... ... ... ... ... ... Appendices Appendix A -References Appendix B -Boring Logs TABLE OF CONTENTS (Continued) Appendix C -Laboratory Testing Procedures and Test Results Appendix D -General Earthwork and Grading Specifications 8900881-01 Table 1 -Seismic Parameters for Active and Potentially Active Faults 7 Figures Figure 1 -Site Location Map ...... . Figure 2 -Regional Seismicity and Index Map Plate 2 6 Plate 1 -Geotechnical Map . . . . . . . . . . . . . . . . . . . . In Pocket -ii - LEIGHTON AND ASSOCIATES, INC. ... .. ... .. .. ... .. .. ... .. ... ... ... -... ... .. ... ... ... -... ... ... ... ... ... -... --... 8900881-01 1.0 · INTRODUCTION This report presents the results of our geotechnical investigation at the subject site. The purpose of our investigation was to identify c1,1d evaluate the geotechnical conditions present on the site and to provide geotechnical recommendations regarding the proposed development. Our scope of services for this investigation included the following: • Review of available published and unpublished geologic literature pertaining to the site (Appendix A). • Review of stereoscopic aerial photographs to assess the general geology of the site . • Geologic reconnaissance of the subject property. • Subsurface exploration consisting of the drilling, logging and sampling of four small-diameter borings (two per tank site). The locations of the borings are shown on Plate 1. The logs of the borings are presented in Appendix B . • Laboratory testing of representative undisturbed and bulk samples obtained from our subsurface exploration (Appendix C) . • Geotechnical evaluation of the data obtained. • Preparation of this report presenting our findings, conclusions and recommendations relative to the proposed development . 2.0 SITE DESCRIPTION AND PROPOSED CONSTRUCTION The site is an rectangular-shaped parcel of land.approximately 2-3/4 acres in total area, located south of Palomar Airport Road between Interstate 5 and El Camino Real in Carlsbad, California (Site Location Map, Page 2). The property is located east of and adjacent to two smaller steel water tanks each approximately 1.25 million gallons in size. Topographically, the property slopes gently to the east at an average gradient of 10 to 15 percent. The site is currently used for agricultural purposes, with no existing structures being present. Based on our review of the preliminary site plans (Right-of-Way 1990), we understand that the proposed construction will consist of two ±8.2 mill ion gallon steel water tanks each having a diameter of 164 feet. Grading of the site will involve the construction of building pads for the tanks which will consist of relatively minor cuts along the western edge of the property and the placement of 10 to 15 feet of fill soils on the eastern portion. Based on our conversations with Mr. Robert Coates, we also understand that the area directly adjacent to each tank will be paved. -1 - LEIGHTON AND ASSOCIATES, INC. .. ------------------------------------------- -... -... -... -... .. ... " / II ' " BA 33 0 2000 scale ,, ' ll . ,I-, ,, Ii .. ---~ . r IQUITOS LA c;;'OST ·~ 4000 feet SITE LOCATION MAP _.,'\ I \ ,,_, .. ... Base Map: Enemas Quadrangle, Caifomia -San Diego CoWlty, 7.5 Mnite Series (Topogaphic}, SE/ 4 Oceanside 15' Quadrangle, US.GS, 1968, Photorevised 1975, AMS 2550 I SE-Series V895 MACDONALD-STEVENS/TANK SITE j Carlsbad, California Project No. 8900881-01 Date 10/02/90 []a[I] 1040 889 Figure No. 1 I ... .. ... .. ... .. .. .. ... .. .. .. ... .. ... ... ... -... -.. .. ... - .. ... -... .. ----... 8900881-01 3.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING Our subsurface exploration program consisted of the drilling of four 8-inch- diameter borings to a maximum depth of 21.5 feet. The approximate locations of these borings are shown on Plate 1. The purpose of this program was to evaluate the engineering characteristics of the onsite soils. All of the borings were logged, and representative bulk and undisturbed samples were obtained by a geologist from our firm. Logs of the borings are presented in Appendix B. Subsequent to logging and sampling, the borings were backfilled . Laboratory testing was performed on representative samples of the soils encountered during the drilling operation. Laboratory testing included determination of in-place moistures and densities, determination of the soils' maximum dry density, remolded shear tests and consolidation tests. A discussion of the tests performed and a summary of the results are presented in Appendix C . -3 - LEIGHTON AND ASSOCIATES, INC. ,.. .. -... -... -... -... -... -... -... -.. -.. ... -... -... -... -.. .. ... .. .. .. - 8900881-01 4.0 GEOTECHNICAL CONDITIONS 4.1 Regional Geology The subject site is located in the coastal section of the Peninsular Range Province, a California physiographic province with a long and active history in southern California. The Peninsular Range Province is characterized by northwest-trending mountain ranges separated by subpara 11 e 1 fault zones. The mountain ranges are underlain by basement rocks consisting of pre-Cretaceous metavolcanic rock and metasedimentary rocks and Cretaceous igneous rocks of the southern California batholith. Late Cretaceous, Tertiary and Quaternary sediments flank the mountain ranges to the northeast and southeast . Throughout the last 54 mill ion years, the area known as the "San Diego Embayment" has undergone several episodes of marine inundation and subsequent marine regression. This has resulted in a thick sequence of marine and non-marine sediments deposited on the rocks of the southern California batholith with relatively minor tectonic uplift of the area. The Peninsular Range Province is traversed by several major active faults. The Elsinore and San Jacinto Faults (associated with the San Andreas fault system) are the major tectonic features. Both are strike-slip faults with predominantly right-lateral movement. The major tectonic activity appears to be a result of right-lateral movement on faults within the San Andreas fault system. Rolling hills and terraces make up the majority of the landforms in the genera 1 vicinity of the subject site. These topographic features are connected by several valleys. The relatively flat-lying areas in these valleys are generally underlain by Quaternary alluvium and slope wash deposits. · · 4.2 Site Geology Based on our subsurface exploration, analysis of 1953 stereoscopic aerial photographs, and review of pertinent geologic literature and maps (Appendix A), the entire site is underlain by Quaternary-aged terrace deposits. As encountered in our borings, these soils were observed to predominantly consist of orange-brown, moist, dense, fine-to medium- grained silty sands. 4.3 Ground Water Ground water was not encountered in our exploratory borings which extended to a maximum depth of 21. 5 feet. However, it should be noted that fluctuations in the level of ground water may occur due to variations in ground surface topography, subsurface stratification, rainfall, irrigation, and other possible factors which may not have been evident at the time of our investigation . -4 - LEIGHTON AHO ASSOCIATES, INC. ... ... ... ... ... .. ... ... .. ... ... ... ... ... ... ... --... ... ... ... ... - -... -... -... -... ... .. -... 8900881-01 5.0 FAULTING AND SEISMICITY 5.1 Faulting Our review of available geologic literature (Appendix A), indicates that there are no known major or active faults on or in the immediate vicinity of the site. The nearest active regional faults are the Coronado Banks fault zone, located offshore approximately 22 miles southwest of the site and the Elsinore fault zone, located approximately 23 miles northeast of the site • The Rose Canyon fault is approximately 6 miles west of the site. Since definitive geologic evidence for active faulting on the Rose Canyon fault is not known, the Rose Canyon fault in the San Di ego area has been classified as potentially active based on the criteria set forth by the California Division of Mines and Geology (CDMG 1985). It should be understood, however, that as a result of recent studies in the San Diego area, the California Division of Mines and Geology is currently re- evaluating the classification of the Rose Canyon Fault. Based on the results of recent studies and several ongoing studies, the Rose Canyon Fault zone may soon be reclassified by the State as an active fault . Figure 2 indicates the location of the site in respect to known major faults in the San Diego region. Included in Figure 2 are the approximate epicentral area and magnitude of earthquakes recorded during the period of 1769 to 1973. 5.2 Seismicity The subject site can be considered to lie within a seismically active region, as can all of southern California. Table 1 indicates potential seismic events that could be produced by maximum probable earthquakes. A maximum probable earthquake is the maximum expectable earthquake produced from a causative fault during a 100-year interval. Site-specific seismic parameters included in Table 1 are the distance to the causative faults, Richter earthquake magnitudes, expected peak/repeatable high ground accelerations (RHGA), and estimated period and duration of ground shaking. As indicated in Table 1, the Elsinore fault is considered to have the most significant effect at the site from a design standpoint. A maximum probable earthquake of Richter Magnitude 7.3 on the fault could produce a peak repeatable horizontal bedrock acceleration of approximately 0.23g. If the Rose Canyon Fault is reclassified, the values indicated on Table 1 should be utilized. The effect of seismic shaking may be mitigated by adhering to the current Uniform Building Code or state-of-the~art seismic design parameters of the Structural Engineers Association of California . Secondary effects associated with severe ground shaking following a relatively large earthquake include ground lurching and shallow ground rupture, soil liquefaction and dynamic settlement, seiches and tsunamis . These secondary effects of seismic shaking are discussed below . -5 -LEIGHTON AND ASSOCIATES, INC ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... -... ... ... ... ... -... ... ... ... .. .. .. ... ... - ----- s ' ' CAlJ.f_QRNll _ ---------so.Ji C)J.ltoRHIA LA NACION I FAULT ZONE ·-·-• ....... _.=,.._--=,;•;;.;;;;=""'="""""';;,;;;;a-:.;.~---===""',;:-;:;;=""'="""'"""...li .. IILOIIIETEIIS • • • .. II I LE I MAJOR EARTHQUAKES AND RECENTLY ACTIVE FAUL TS IN THE SOUTHERN CALIFORNIA REGION ACTIVE FAULTS Total lenglh of foul! zone that bfeoh Holocene deposils 111 thal hos hod seismic activity. Foul! segmenl with surfoee ruptu<e during en historic eorthquoke, °' with oseismic fault creep . O Holocene volcanic octivitJ IAmboJ, Pisgah, c.r,,, Prieto cn! Sa111111 &ittnl EXPLANATION" IIH 111+ 1177 IHZO EARTHOUAKE LOCATIONS App,cximote epicentrol oreo ol eorthquok .. thol occurred 1769-1933. Mogn,tud .. not itC111ded by inslruments prior to 1906 were eslimaled from domog• reports ossi9"ed 1111 lntensily W ( t.'cd1fied Mor coli seole) or 1eo1or; lh,s is rouq,Jy equivolent lo Richter M 6.0. 31 moderote- eorthquok ... 7 mojor and on, ,,.o1 earthquake (1857) were reported in the 164-yeor pttiod 1769·1933 . Eatlhquokt epkenltts since 1933, plotted ho:!' inpro,ed instnomenls. 29 """'"'le"" ond tt..e mojor e0<lhquokts were rea,,ded in the 40-yeor period 1933-1973 . • SM LI..,, llt!fl•N, Pncl1t ,-,., t.llti• ._ -4111 .. 1 t1JleNtltlll tf Nf . .. t.41 --•tMIM ., .. Str.chlrll EAti111t"1 A11«1tl_. rf C.lif.,11• Mint I f'ttl ..,,.._._ • • 1W NI I lldts M••••N If 1% If' tfHltr, I NfO' .. ,,.._,,, 1 It 1 l i I ..._,,, ..,,..,..,. , 11 1 • REGIONAL SEISMICITY INDEX MAP :~:::: ::~e s:88~teVMS I][I] Date 10/02/90 Figure No.....s,.2_ 2095 788 I I r I I I r I I I I 1 ·, 1 i I ·, I ., 1 r I I 1 r I f 1 I I I I I 1 f 1 f I * 8900881-01 TABLE 1 SEISMIC PARAMETERS FOR ACTIVE AND POTENTIALLY ACTIVE FAULTS MAXIMUM PROBABLE EARTHQUAKE (Functional Basis Earthquake) Maximum Credible Peak Bedrock/ Duration of Distance Earthquake Repeatable Predominant Strong Potential From Fault Horizontal Period at Shaking at · Causative To Site Richter Richter Ground Acceleration** Site in Site in Fault (Miles) Magnitude Magnitude (Gravity) Seconds Seconds Coronado Banks 22 6,5 6.0 0.10 0.26 6 (offshore) Elsinore 23 7.6 7.3 0.23 0.35 25 San Clemente 54 7.5 7.0 0.06 0.42 7 (offshore) San Jacinto 47 7.6 7.3 0.10 0.41 12 San Andreas 67 8.5 8.3 0.09 0.64 5 Rose Canyon* 6 7.1 6.2 0.36 (0.23) 0.27 15 (offshore) This fault is considered "potentially active," based on .our current knowledge of the geologic conditions of the San Diego County area. ** For design purposes, the repeatable horizontal ground acceleration may be taken as 65 percent of the peak acceleration for the site within approximately 20 miles of the epicenter (after Ploessel and Slosson, 1974). ... ... ' -.. i ... ... .. .. .. .. ... .. ... ... ... .. ... ... ... .. -.. --... ... -.. ... -.. -... ... .. .. .. 8900881-01 5.2.1 Lurching and Shallow Ground Rupture Soil lurching refers to the rolling motion on the surface by the passage of seismic surface waves. Effects of this nature are likely to be significant where the thickness of soft sediments vary appreciably. Due to the relatively dense nature of the onsite soils, damage to the proposed development should not be significant . Breaking of the ground from faulting is not likely to occur on site due to the absence of active faults. Cracking due to shaking from distant seismic events is not considered a significant hazard, although it is a possibility at any site • 5.2.2 Liquefaction and Dynamic Settlement Liquefaction and dynamic settlement of soils can be caused by strong vibratory motion due to earthquakes. Both research and historical data indicate that loose, saturated, granular soils are susceptible to liquefaction and dynamic settlement while the stability of silty clays and clays is not adversely affected by vibratory motion. Liquefaction is typified by a total loss of shear strength in the affected soil layer, thereby causing the soil to flow as a liquid. This effect may be manifested by excessive settlements and sand boils at the ground surface. · The onsite materials below the ground water table are not considered liquefiable due to their high density characteristics, along with the low ground water table elevation . -8 - IEIGHTON AND ASSOCIATES, INC. -... - "" i ... ... - .. ... - ... ... -... ... ... ... ... ... ... -... ... ... -... -... -... -... ... ... -- 8900881-01 6.0 CONCLUSIONS The results of our investigation indicate that the subsurface conditions are generally favorable for the proposed development. The proposed construction is feasible from a geotechnical standpoint provided the following recommendations are incorporated into the final design and construction of the project. The following is a summary of the main geotechnical factors which may affect development of the site. • Active faults are not known to exist on or in the immediate vicinity of the site . • The maximum anticipated bedrock accelerations on the site is estimated to be 0.23g based on a maximum probable earthquake of Richter Magnitude 7.3 on the active Elsinore Fault zone. • Ground water was not encountered at the time of our investigation . • Soils encountered during our investigation are anticipated to have a low potential for expansion. -9 - LEIGHTON AND ASSOCIATES, INC. ... ... -... ... ... ... ... ... ... -... -... -... ... ... ... ... ... ... ... -.. ... ... ... ... --... ... ... .. 8900881-01 7.0 RECOMMENDATIONS 7 .1 Earthwork Grading and earthwork should be performed in accordance with the following recommendations and the General Earthwork and Grading Specifications included in Appendix D. In case of conflict, the following recommendations shall supersede those in Appendix D . 7.1.1 Site Preparation Prior to grading, all areas to receive structural fill or ~ngineered structures should be cl eared of surface and subsurface obstruct ions, including any existing debris, and stripped of vegetation. Removed vegetation and debris should be properly disposed of off site. Holes resulting from removal of buried obstructions which extend below finished site grades should be replaced with suitable compacted fill material. Where not removed by proposed grading, the topsoil layer should be removed and recompacted. All areas to receive fill should be scarified to a minimum depth of 12 inches, brought to near optimum moisture conditions and recompacted to at least 90 percent relative compaction {based on ASTM Test Method D1557-78). 7.1.2 Excavations The onsite materials are expected to be rippable with conventional earthmoving equipment . 7.1.3 Trench Excavation and Backfill Excavation of utility trenches and foundations in the onsite terrace deposits appears to be feasible with heavy-duty backhoe equipment . The onsite soils may be used as trench backfill provided they are screened of organic matter, rock fragment~greater than 6 inches in diameter, and debris. Trench backfill should be compacted in uniform lifts {not exce·eding 8 inches in thickness) by mechanical means to at least 90 percent relative compaction {ASTM Test Method D1557-78) . 7.1.4 Fills The onsite soils are generally suitable for use as compacted fill provided they are free of organic material and debris. A 11 fi 11 soils should be brought to near-optimum moisture conditions and compacted in uniform lifts to at least 95 percent relative compaction based on laboratory standard ASTM Test Method D1557-78. The optimum lift thickness required to produce a uniformly compacted -10 - LEIGHTON AND ASSOC/AT~ INC. .. ... .. ... ... ... .. ... .. 8900881-01 fill will depend on the type and size of compaction equipment used . In general, fill should be placed in lifts not exceeding 8 inches in thickness . 7.1.5 0verexcavation of Daylight Building Pads The cut portion of the tank pads should be overexcavated to a minimum depth of 6 feet below finished grade and replaced with compacted fill (see Appendix D for Transition Lot Detail). The base of the overexcavation should extend at least 6 feet outside the footprint of the proposed tanks. 0verexcavation of daylight pads is recommended in order to minimize the potential for differential settlements between cut and fill transitions. • 7.2 Foundation Design .. .. ... ... ... .. .. .. ... .. ... ... -... .. .. ... ... -.. -... ... .. The ring wans of the proposed water tanks may be supported on continuous footings bearing in the properly compacted fi 11 at a minimum depth of 18 inches beneath lowest adjacent finish grade (for low expansive soils). At this depth, footings may be designed for an allowable soil bearing value of 5,000 psf. This value may be increased one-third for loads of short duration, such as wind or seismic forces .. Footings should have a minimum width of 24 inches, and minimum reinforcement consisting of two No. 4 bars, one top and one bottom. Actual reinforcement as well as concrete strength should be based on the recommendations of the structural engineer . 7.3 Lateral Earth Pressure and Lateral Resistance If retaining walls are proposed, the following earth pressure ~alues for level or sloping backfill are recommended for walls backfilled with onsite nonexpansive soils . Equivalent Fluid Weight (pcfl Conditions Active At-Rest Passive 35 60 300 2:1 Slope 65 70 150 (Sloping Down) Unrestrained (yielding) cantilever walls should be designed for an active equivalent fluid weight value provided above. In the design of walls restrained from movement at the top (nonyielding), the at-rest equivalent fluid weight value should be used. The above values assume nonexpansive backfill and free-draining conditions. Should a sloping backfill other than 2: 1 (horizontal to vertical) be designed, or if a backfi 11 is loaded by an adjacent surcharge load, the equivalent fluid weight values provided above should be evaluated on an individual-case basis by the geotechnical engineer. All retaining wall structures should be provided with -11 - LEIGHTON AND ASSOCIATES, INC. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .. ... ... ... ... -... -... -... ... ... ... ... .. ... ... -... 8900881-01 appropriate drainage. Typical drainage design is illustrated in Appendix D. The total depth of retained earth for design of cantilever walls should be the vertical distance below the ground surface measured at the wall face for stem design or measured at the heel of the footing for overturning and sliding calculation. Wall footings should be designed in accordance with structural considerations and the recommendations above. Wall backfill should be compacted by mechanical methods to at 1 east 90 percent relative compaction based on ASTM Test Method D1557-78 . Soil resistance developed against lateral structura 1 movement can be obtained from the passive pressure value provided above. Further, for sliding resistance, a friction coefficient of 0.35 may be used at the concrete and soil interface. The passive value may be increased by one- third when considering loads of short duration including wind or seismic 1 oads. The total lateral resistance may be taken as the sum of the frictional and passive resistances provided that the passive portion does not exceed two-thirds of the total resistance . 7.4 Settlement Considerations The potential for settlement of the fill soils was estimated assuming the following conditions: • The entire site will be overexcavated to a depth of 6 feet and replaced with fill material compacted to at least 95 percent relative compaction . • The fill material is drained . • Each water tank has an approximate height of 50 feet . • The ring wall footings are embedded at a depth of 18 inches below finish grade. • The ring wall footings are designed for a maximum bearing pressure of 5,000 psf. Using these assumptions, the maximum anticipated settlement beneath each water tank was estimated to be on the order of one inch. The differential settlement across each tank was calculated to be approximately 1/2 inch. In our professional opinion, these values are considered to be within tolerable limits for such structures provided our recommendations are incorporated into the design and construction of the water tanks. Most of the estimated settlements are anticipated to occur during or shortly after construction . 7.5 Surface Drainage and Erosion Surface drainage should be controlled at all times. The subject structures should have appropriate drainage systems to collect roof runoff. Positive surface drainage should be provided to direct surface water away from the structures toward suitable drainage facilities. Positive drainage may be -12 - LEIGHTON AND ASSOCIATES, INC. ... .. .. .. ... .. ... ... .. ... .. .. .. ... .. .. .. .. .. ... .. .. .. .. -.. -.. .. .. .. ... .. ... .. ... -.. 8900881-01 accomplished by providing a minimum 2 percent gradient from the structures. In general, ponding of water should be avoided adjacent to the structures . In order to help reduce the potential for excessive erosion of graded slopes, we recommend berms and/or swales be provided along the top of the slopes and lot drainage directed such that surface runoff on the slope faces is minimized. Protective measures to mitigate excessive site erosion during construction should also be implemented in accordance with the latest City grading ordinances . 7.6. Construction Observation The recommend at ions provided in this report are based on subsurface conditions disclosed by our subsurface exploration. The interpolated subsurface conditions should be field checked during construction by a representative from Leighton and Associates. All foundation excavations and grading operations should be observed by a representative of this firm so that construction is performed in accordance with the recommendations of this report. Final grading plans should be reviewed by this office prior to construction . -13 - LEIGHTON AND ASSOCIATES, INC ' . ... ... ... ... ... ... ... .. .. -.. ... -.. ... ... .. .. .. ... .. .. -... .. ... .. ... .. ... .. .. -.. ... .. 8900881-01 APPENDIX A References Albee, A.L., and Smith, J.L., 1966, Earthquake Characteristics and Fault Activity in Southern California, in Lung, R., and Proctor, R., eds., Engineering Geology in Southern California, Association of Engineering Geologists, Special Publication, dated October 1966 . Allen, C.R., Amand, P., Richter, C.F., and Nordquist, J.M., 1965, Relationship Between Seismicity and Geologic Structure in Southern California, Seismological Society of America Bulletin, Vol. 55, No. 4, pp. 753-797 . Bolt, B.A., 1973, Duration of Strong Ground Motion, Proc. Fifth World Conference on Earthquake Engineering, Rome, Paper No. 292, pp. 1394-1313, dated June 1973 . Bonilla, M.J., 1970, Surface Faulting and Related Effects, in Weigel, R., ed., Earthquake Engineering, New Jersey, Prentice-Hall, Inc., pp. 47-74 . Greensfelder, R.W., 1974, Maximum Credible Rock Accelerations from Earthquakes in California, California Division of Mines and Geology, Map Sheet 23 • Hannan, D.L., 1975, Faulting in the Oceanside, Carlsbad, and Vista Areas, Northern San Diego County, California, in Ross, A. and Dowleri, R.J., eds., Studies on the Geology of Camp Pendleton and Western San Diego County, California, San Diego Association of Geologist Field Trip Guidebook, pp. 56-60 . Lamar, D.L., Merifield, P.M., and Proctor, R.J., 1973, Earthquake Recurrence Intervals on Major Faults in Southern California, in Moran, D.E., Slosson, J.E., Stone, R.D., Yelverton, C.A., eds., 1973, Geology, Seismicity, and Environmental Impact: Association of Engineering Geologists, Special Publication . Leighton and Associates, Inc., Unpublished In-House Data . Ploessel, M.R., and Slosson, J.E., 1974, Repeatable High Ground Accelerations from Earthquakes -Important Design Criteria, California Geology, Volume 27, No. 9 . Right-of-Way Engineering Services, Inc., 1990, Twin D Reservoir Site, dated August 27, 1990 . San Diego, County of, 1985, Orthotopographic Survey, Scale 1"=200', Sheet No. 318-1683 . ---, 1985, Orthotopographic Survey, Scale=l"=200', Sheet No. 322-1683 . A-1 .. ... .. ... .. ... .. ... .. ... .. ... -... -... .. ... ... -... ... ... -... ... -... ... ... ... ... .. -... -... ... 8900881-01 References (Continued) Schnabel, B., and Seed, H.B., 1974, Accelerations in Rock for Earthquakes in the Western United States, Bulletin of the Seismological Society of America, Volume 63, No. 2, pp. 501-516 . Seed, H.B., Idriss, I.M., and Kiefer, F.W., 1969, Characteristics of Rock Motions During Earthquakes, Journal of Soil Mechanics and Foundation Division, ASCE, Volume 95, No. SM5, Proc. Paper 6783, pp. 1199-1218 . Seed, H.B., 1979, Soil Liquefaction and Cyclic Mobility Evaluation for Level Ground During Earthquakes, ASCE, GT2, p. 201, dated February . Wilson, K.L., 1972, Eocene and Related Geology of a Portion of the San Luis Rey and Encinitas Quadrangles, San Diego, California. A-2 ·-... .. --... .. .. ... ... .. .... .. .. ... .. ... .. ... ... ... .. ... ... ... -... .. ... ... ... --.. .. -... GEOTECHNICAL BORING LOG Date September 11, 1990 Drill Hole No. B-1 _.....;;.....,;;. __ _ Project MacDonald-Stevens/Tank Site Drilling Co. GeoDrill Sheet 1 of 1 8900881-01 Hollow Stem Auger Hole Diameter 8-inches Project No. Type of Rig Ori ve Weight ---=-14.:..:0:_:..l b=-=s=------Drop 30 in. Elevation Top of Hole 366± .c:-tJ -~ ........ .c: "' C. QI C. 0 QI QI .,, -I c"-.. ~ '-" 0 :if;Y{ .:!£fi "' QI "C :::, .... -~ ..., .... <C 0 ..., z "' 0 QI 30 ..c QI :::,-0 u. I-C. -.. E a, QI .,, 0.. V, -- 1 80 - ~ 2 76 ~ ~ ~ 3 92 >, ..., -~ en-<='+- QI tJ Q C. t Q 119.2 110.6 118.0 Ref. or Datum Mean Sea Level (MSL) .... QI .. . :::J+' +-' C "' QI -~+' oc ::e: 0 u 12.3 11.4 12.5 .,;-"' . .,, V, -u u. ~"'! ·o => V')~ SM SP- SM SP- SM SP- SM GEOTECHNICAL DESCRIPlION Logged by JB Sampled by JB TERRACE DEPOSITS: @ 5' Light to medium orange-brown, damp to moist, dense, silty, fine to medium grained sand @ 10' Medium orange-brown, moist, dense, slightly silty, fine to medium grained sand; uniform @ 15' As Above @ 20' As Above -i=idi:-/·._ 4 83 119.4 12.6 -- -- -- 25--Total Depth= 21.5 Feet --No Ground Water Encountered Backfilled 9-11-90 -- -. 30 I Alnhtnn anti At11.nr.h:1:tat Int'!_ I ·-... ... ... ... ... ... ... ... ... .. ... --... .. ... -... -... .. ... ... ... ... ... ... .. .. ... ... ... ... ... ... .. -- GEOTECHNICAL BORING LOG Date September 11, 1990 Drill Hole No. B-2 ------Project MacDonald-Stevens/Tank Site Project No . Sheet 1 of 1 8900881-01 Drilling Co. GeoDrill Type of Rig Hollow Stem Auger Hole Diameter 8-inches Ori ve Wei gh t ___ .:.14.:.:0:.......,.1.:,.b s,,__ ___ _ Drop 30 in. Elevation Top of Hole 358+ Ref or Datum . Mean Sea Level { MSL) ->, N .,;-"' . .... QI GEOTECHNICAL DESCRIPl ION ..c:~ ... QI 0 .... ·-,_ . "' . ........ ·-"O z "' 0 ,n-:::, .... "' "! 0. QI ..c: en :::, QI 30 C: .... .... C: -u QI QI 0. 0 .... .Q QI o"-QI ... "' QI u. Logged by JB "' ..I :::,-C 0. c"-,_ ·-I-0. -,_ -·-.... -"! -~ .... E a:) QI t 0 C: Samp l e·d .... z: 0 ·-:::, by JB < "' Q. s=l-(/') C u 0 :il1~ -TERRACE DEPOSITS: - -- --SP-@ 5' Light orange-brown, moist, dense, SM silty, fine to medium grained sand; 5-uniform 1 92 117 .5 11.l - -© -. . II ~ SP-@ 10' Light to medium orange-brown, moist, 10-SM dense, slightly silty, fine to 2 67 116.6 10.4 medium grained sand, with some coarse . grains of sand . .. . .. . .. SP-@ 15' Light to medium orange-brown, moist, 15-SM dense, slightly silty, fine to ' 3 60 111.7 ll.4 medium grained sand; predominantly -medium grained sand ' - I~ -----@ 20' Medium orange-brown, moist, dense, 20-SP-slightly silty, fine to medium 4 75 107 .5 10.7 SM grained sand; slightly micaceous -; t:-:·:-:. "7-' ! ----- 25-- --Total Depth = 21.5 Feet No Ground Water Encountered --Backfilled 9-11-90 -. .. 30 Lelahton and A ■,u,clates. Inc. ... ... .. ... -... -... .. ... -... .. ... .. -.. ... -... -.. -.. ---.. -.. -.. -.. -... Date September 11, 1990 GEDTECHNICAL BORING LOG Drill Hole No. B-3 Project MacDonald-Stevens/Tank Site Sheet 1 of 1 Project No • __;;;8.:c.90;:..;0:..:8""B"""l--'O:..:l'---- Type of Rig Hollow Stem Auger Drilling Co. GeoDrill Hole Diameter 8-inches Drive Weight ---~1..:..:40=-.!l.::.b.:c.s____ Drop 30 in. Elevation Top of Hole 360+ Ref or Datum . Mean Sea Level (MSL) >, .. .;-. .... GEOTECHNICAL u "' 0 .... -~ .. "' . DESCRIPl ION .s:-.. I-. ...... ·~ "C z "' 0 111~ ::J ... "' "! a. .. .s: C'I ::J .. 30 C'+-... C -..., a. 0 .... ..0 .. o"-.. u "' .. u . Logged by JB .... "'..J ::J -Q C. Q LL. I-·~ I-C. -I--·~ ... -V) -<.!J .... E C0 .. t 0 C ~:;; JB .... ::E 0 Sampled by "' Q. ~-< V) Q u 0 --TERRACE DEPOSITS: . -- . ----@ 5' Light orange-brown, damp to slightly SM 5-moist, dense, silty, fine to medium 1 92 116.4 13.0 grained sand; slightly micaceous ---. ~ -.. SM @ 10' Light red-brown to orange-brown, lD-moist, dense, silty, fine to medium grained sand . 2 80 121.0 11.5 . ~ . © ~ . .. SP-@ 15' Light orange-brown, moist, dense, 15-SM slightly silty, fine to medium 3 91 118.6 11.8 grained sand; slightly micaceous --.. ---- 20-SP-@ 20' Light orange-brown, moist, dense, 4 92 SM slightly silty, fine to medium -117 .s 8.7 grained sand; with some coarse sand .. qrains --.. -- 25-----Total Depth 21.5 Feet = --No Ground Water Encountered Backfilled 9-11-90 - - 30 Lelahton and Aaaoclatea, Inc. .. .. .. .. .. ... ... ... .. ... ... .. -.. -.. -.. .. ... .. .. .. -.. -.. .. ... ---.. .. .. .. ... GEOTECHNICAL BORING LOG Date September 11, 1990 Drill Hole No. B-4 Project MacDonald-Stevens/Tank Site Project No . Sheet l of 1 8900881-01 Drilling Co. GeoDrill Hole Diameter 8-inches Elevation Top of Hole 377+ 0 ... (:".·:~/S-: . •,; ~-~--~ · b}:S\ ·~ .... .... < 0 z .. .0 .. :::,~ I-C. E ,a VI - 0: - - - - - - 1 - - .... VI 0 3: 0 o,.._ ~ '-a, .. Q. No 102 >, .... -~ VI- C: .... .. u Q C. -t Q ecov Type of Rig Hollow Stem Auger Drive Wei g ht ___ ..:1...:.4.:c.O _l:..:b:..::s'------Drop 30 in. Ref. or Datum Mean Sea Level 1MSL) ... .. '-. :::, .... .... C: VI a, -~ .... 0 C: ::E 0 u ~ry VI- VI • ,a V, ~..; u. ~"' ·~ :i ~- SM SP- GEOTECHNICAL DESCRIPlION Logged by JB Sampled by __ J_B __ _ TERRACE DEPOSITS: @ 5' Light brown to light brown-orange,dry to damp, dense, silty, fine grained sand 104.4 8.9 SM @ 10' Light to medium orange-brown, moist, very dense, slightly silty, fine to medium grained sand; slightly micaceous 2 SP-95 109.9 9.0 SM @ 15' Medium orange-brown, moist, dense, slightly silty, fine to medium grained sand - - - 3 94 - -- -- 25-- -- --. . 30 102.7 8.7 SP- SM @ 20' Medium orange-brown, moist, dense, slightly silty, fine to medium grained sand; micaceous Total Depth= 21.5 Feet No Ground Water Encountered Backfilled 9-11-90 Lelchton and Associates. Inc. ··---... ... ... -... ... ... ... ... ... ... ... ... ... - -... ... ... -... -... -... -... -... -... --... - 8900881-01 APPENDIX C Laboratory Testing Procedures and Test Results Moisture and Density Tests: Moisture content and dry density determinations were performed on relatively undisturbed samples obtained from the test borings and/or trenches. The results of these tests are presented in the boring and/or trench logs. Where applicable, only moisture content was determined from "undisturbed" or disturbed samples . Classification Tests: Typical materials were subjected to mechanical grain-size analysis by wet sieving from U.S. Standard brass screens (ASTM D422). Hydrometer analyses were performed where appreciable quantities of fines were encountered . The data was evaluated in determining the classification of the materials. The grain-siie distribution curves are presented in the test data and the Unified Soil Classification is presented in both the test data and the boring and/or trench 1 ogs . Atterberg Limits: The Atterberg Limits were determined in accordance with ASTM D423 for engineering classification of the fine-grained materials . Direct Shear Tests: Direct shear tests were performed on selected remolded and/or undisturbed samples which were soaked for a minimum of 24 hours under a surcharge equal to the applied normal force during testing. After transfer of the sample to the shear box, and reloading the sample, pore pressures set up in the sample due to the transfer were allowed to dissipate for a period of approximately 1 hour prior to application of shearing force. The samples were tested under various normal loads, a motor-driven, strain-controlled, direct- shear testing apparatus at a strain rate of 0.005 inches per minute. After a travel of 0.300 inches of the direct shear machine, the motor was stopped and the sample was allowed to "relax" for approximately 15 minutes. The "relaxed" and "peak" shear values were recorded. It is anticipated that, in a majority of samples tested, the 15 minutes relaxing of the sample is sufficient to allow dissipation of pore pressures set up in the samples due to application of shearing force. The relaxed values are therefore judged to be a good estimation of effective strength parameters. The test results were plotted on the "Direct Shear Summary". For residual direct shear test, the samples were sheared, as described in the preceding paragraph, with the rate of shearing of 0.001 inches per minute. The upper portion of the specimen was pulled back to the original position and the shearing process was repeated until no further decrease in shear strength was observed with continued shearing (at least three times resheared). There are two methods to obtain the shear values: (a) the shearing process was repeated for each normal load applied and the shear value for each normal load was recorded . One or more than one specimen can be used in this method; (b) only one specimen was needed, and a very high normal load (approximately 9000 psf) was applied from the beginning of the shearing process. After the equilibrium state was reached (after "relaxed"), the shear value for that normal load was recorded. The normal loads were then reduced gradually without shearing the sample (the motor was stopped). The shear values were recorded for different normal loads after they were reduced and the sample was "relaxed" . C-1 ..... ... ... ... ... ... ... .. -... .. ... .. ... .. ... ... ... ... .. ... ... ... .. ... ... ... .. ... .. ... ---.. ... ... 8900881-01 Laboratory Testing Procedures {Cont'd.) Maximum Density Tests: The maximum dry density and optimum moisture content of typical materials were determined in accordance with ASTM 01557-78 (five layers). The results of these tests are presented in the test data . Expansion Index Tests: The expansion potential of selected materials was evaluated by the Expansion Index Test, U.B.C. Standard No. 29-2. Specimens are molded under a given compactive energy to approximately the optimum moisture content and approximately 50 percent saturation or approximately 90 percent relative compaction. The prepared I-inch thick by 4-inch diameter specimens are loaded to an equivalent 144 psf surcharge and are inundated with tap water until volumetric equilibrium is reached. The results of these tests are presented in - the test data . Consolidation Tests: Consolidation tests were performed on selected, relatively undisturbed samples recovered from the sampler. Samples were placed in a consolidometer and loads were applied in geometric progression. The percent consolidation for each load cycle was recorded as the ratio of the amount of vertical compression to the original I-inch height. The consolidation pressure curves are presented in the test data. Where applicable, time-rates of consolidation were also recorded. A plot of these rates can be used to estimate time of consolidation . Soluble Sulfates: The soluble sulfate contents of selected samples were determined by the California Materials Method No. 417 . "R"-Value: The resistance "R"-value was determined by the California Materials Method No. 301 for base, subbase, and basement soils. Three samples were prepared and exudation pressure and "R"-va l ue determined on each one. The graphically determined "R"-value at exudation pressure of 300 psi is reported . Tri axial Compression Tests: Tri axial compression tests were performed on selected remolded and/or undisturbed samples according to ASTM 2166 (unconfined) and ASTM 2850 (confined) . C-2 ... ... ... ... ... .. ... .. ... .. -• loll O.tcriplon: ~of~: 3000 ,_ LoediOQ Rate: • I 2500 I : I Ta □, silt~. r.;la~e~ ~ I sand []Remolded to _.1Q. 'I AelallYe ~ctlon D l.kldlatu'bed I 0.05 In.I.min. i I T • I i i i .. a. 2000 ._..ldl ~ w -a:: I-m : i 1600 ... ... ... ... ... ... ... ... ... ... -... ... ... 1000 / / ( ' 500 0 Sample Location B-2, (D I i ! ! I / "' I ! I I • 500 Symbol 0 . / / / ( 1/ ,,. / I I I . 1 I • : ! T 1000 1600 NORMAL STRESS, pat Average Moisture Contenta ./ I . I ! I . I I . I i : ! 2000 Before After Friction Angbt 9 .4 N/A 31 2500 Cohesion 857.5 3000 Remarks DIRECT SHEAR TEST RESULTS Project No. 69QQ66J -Ql r1fefT7 Project Nalfte MacDonald-Stevens lLW Date 10/1/90 figure No. C-3 3015 1088 .... '------------------.L...:::==~==~~:.:..=:.===;:::;:=--=.!!..~:!- ... Sol 0.Krlptk)n: Ian siJty sand I ... ~of~: (]Remolded to _1Q_ ~ ... Relat!Y• ~ction ... ... 3000 0lkldllh.rlled I ,_ Loading Rate: a □4s ln./mn i I • I • ... I I I I ... 2500 ... I • I -I .. I : -• I a. 2000 .. I a; If) w ... I!:: If) : i 1500 .. .. .. .. ... .. ... .. ... ... ... .. .. 1000 500 / / \ 1 0 Sample Location B-4; u) I i I • ! I I I : ! I I / / / ) • 500 Symbol 0· I I /'h • ! /1 / ! / I / I I ,/ I . I / . I '/ ! A ) I / I I i i ; I : T 1000 1500 2000 NORMAL STRESS. pef Average Moisture Contents Bafora After Friction Angle 9.1 N/A 32.4 2f500 Cohesion 291.5 Project No. 8900881-01 DIRECT SHEAR TEST RESULTS Project Name MacDonaJ d-Steyens Date 10/1 /90 Figura No. G· 4 ... Remark• [fill 30111018 ;.. SOIL TYPE OR OPTIMUM MAXIMUM SAMPLE LOCATION SOIL DESCRIPTION MOISTURE ('!I.) DRY DENSITY (pc "'"1--------+--------------~f-------t------~ ;.. ... ... ... .. .. .. .. .. .. .. .. .. ... ... ... .. ... ... ... .. ... -... ... .. -... ... ... -... -- B-4, CD B-2, G) Brown, silty sand Orange, silty sand TEST METHOD: ASTM D1557-7B MAXIMUM DENSITY TEST RESULTS 8.5 9.0 Project No. 8900881-01 Project Name MacDonaJ ct-Stevens Date 10/1/90 Figure No. C-5 131. 5 130.0 [1j[I] 3050 688 -.. ... .. -,.. ... .. ... .. .. .. .. .. .. .. -.. ... .. ... .. ... .. ... .. -.. -.. -.. .. .. .. .. ... .. ..... IO IO GI C -" () :c I- GI a. e Ill rn -0 c GI () .. GI 0. ..... z Q I-< 0 :J 0 (/) z 0 9 . (.) 12. 14 . 0 Rllcatea Sample at Field Moisture -Loading PRESSURE (kipa per Square Foot) • Indicates Sample After Satiratlon ---Rebound 5.0 10.0 BORING NO.: 8-4 SAMPLE NO.: 0 Project No. 8900881-Ql DEPTH (FT): 0 SOL TYPE: SM to 5 {Remolded to CONSOLDATION-PRESSURE CURVE Project Name MacDona 1 rt-Steve as Date ]QI) (9D Figure No. C-6 [lj[l] 3010 188 -... ... ... -.. -.. .. 11111 .. 11111 ... .. ... ... -... .. .. ... ... -... .. ... .. ... .. ... -... -... -.. -... ,.. ., ., a, C -"' .2 t= a, a. E as (1' -0 c a, C) .. a, a. .... 0.05 z Q I-< e ..J 0 rn z 0 9 . 0 12 . 14. 0 hdlcatea Sample at Field Moisture -Loading PRESSURE (k~a per Square Foot) 0.5 1.0 • Indicates Sample After Saturation BORING NO~ SAMPLE NO~ B-4 © DEPTH (FT): 0 to 5 son. TYPE: SM ( Remo 1 de to 90% ---Rebound Project No.__,8""9""'0""08=<>8""1'---"'0=-l ____ ~ITT CONSOLOATK>N-PRESSURE CURVE Project Name Macdaoa J d-Steveos WW Date )Q/) (90 Figure No. C-7 3010 188 --.. .. .. .. .. .. .. "" .. .. .. .. .. .. .. -.. ... .. ... .. -... -.. - ... .. -.. -... -... 8900881-01 APPENDIX D General Earthwork and Grading Specifications 1.0 General Intent The~e specifications are presented as general procedures and recommendations for grading and earthwork to be utilized in conjunction with the approved grading pl ans. These general earthwork and grading specifications are a part of the recommendations contained in the geotechnical report and shall be superseded by the recommendations in the geotechnical report in the case of conflict. Evaluations performed by the consultant during the course of grading may result in new recommendations which could supersede these specifications or the recommendations of the geotechnical report. It shall be the responsibility of the contractor to read and understand these specifications as well as the geotechnical report and approved grading plans . 2.0 Earthwork Observation and Testing Prior to the commencement of grading, a qualified geotechnical consultant should be employed for the purpose of observing earthwork procedures and testing the fills for conformance with the recommendations of the geotechnical report and these specifications. It shall be the responsibility of the contractor to assist the consultant and keep him apprised of work schedules and changes, at least 24 hours in advance, so that he may schedule his personnel accordingly. No grading operations should be performed without the knowledge of the geotechnical consultant. The contractor shall not assume that the geotechnical consultant is aware of all grading operations . It shall be the sole responsibility of the contractor to provide adequate equipment and methods to accomplish the work in accordance with applicable grading codes and agency ordinances, recommendations in the geotechnical report and the approved grading plans not withstanding the testing and observation of the geotechnical consultant. If, in the opinion of the consultant, unsatisfactory conditions, such as unsuitable soil, poor moisture condition, inadequate compaction, adverse weather, etc., are resulting in a quality of work less than recommended in the opinion of the consultant, unsatisfactory conditions, such as unsuitable soil, poor moisture condition, inadequate compaction, adverse weather, etc., are resulting in a quality of work less than recommended in the geotechnical report and the specifications, the consultant will be empowered to reject the work and recommend that construction be stopped until the conditions are rectified. Maximum dry density tests used to evaluate the degree of compaction should be performed in general accordance with the latest version of the American Society for Testing and Materials test Method ASTM D1557 . 3.0 Preparation of Areas to be Filled 3.1 Clearing and Grubbing: Sufficient brush, vegetation, roots, and all other deleterious material should be removed or properly disposed of in a method acceptable to the owner, design engineer, governing agencies, and the geotechnical consultant . D-1 ,.. ... ,.. ,.. ,.. .. ,.. .. ,.. .. ... .. ... .. ... -.. .. .. .. .. .. ... ---.. ... -... 8900881-01 General Earthwork and Grading Specifications (Cont'd.) The geotechni cal consultant should evaluate the extent of these removals depending on specific site conditions. In general, no more than 1 percent (by volume) of the fill material should consist of these materials and nesting of these materials should not be allowed. 3.2 Processing: The existing ground which has been evaluated by the geotechnical consultant to be satisfactory for support of fill, should be scarified to a minimum depth of 6 inches. Existing ground which is not satisfactory should be overexcavated as specified in the following section. scarification should continue until the soils are broken down and free of large clay lumps or clods and until the working surface is reasonably uniform, flat, and free of uneven features which would inhibit uniform compaction . 3.3 Overexcavation: Soft, dry, organic-rich, spongy, highly fractured, or otherwise unsuitable ground, extending to such a depth that surface processing cannot adequately improve the condition, should be overexcavated down to competent ground, as evaluated by the geotechnical consultant. For purposes of determining quantities of materials overexcavated, a licensed land surveyor/civil engineer should be utilized . 3.4 Moisture Conditioning: Overexcavated and processed soils should be watered, dried-back, blended, and/or mixed, as necessary to attain a uniform moisture content near optimum . 3. 5 Recompact ion: Overexcavated and processed soils which have been properly mixed, screened of deleterious material, and moisture- conditioned should be recompacted to a minimum relative compaction of 90 percent or as otherwise recommended by the geotechnical consultant. 3.6 Benching: 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 should be a minimum of 15 feet wide, at least 2 feet into competent material as evaluated by the geotechnical consultant. Other benches should be excavated into competent material as evaluated by the geotechnical consultant. Ground sloping flatter than 5:1 should be benched or otherwise overexcavated when recommended by the geotechnical consultant . 3.7 Evaluation of Fill Areas: All areas to receive fill, including processed areas, removal areas, and toe-of-fill benches, should be evaluated by the geotechnical consultant prior to fill placement . 4.0 Fill Material 4.1 General: Material to be placed as fill should be sufficiently free of organic matter and other deleterious substances, and should be evaluated by the geotechnical consultant prior to placement. Soils of poor gradation, expansion, or strength characteri sties should be pl aced as recommended by the geotechnical consultant or mixed with other soils to achieve satisfactory fill material . 0-2 .... ... .. ... "" "" ... ... .. ..... ... .. ... .. ... .. .. .. .. ... ... ... ... ... -.. -.. ... ... ... ... -- 8900881-01 General Earthwork and Grading Specifications (Cont'd.) 4.2 Oversize: Oversize material, defined as rock or other irreducible material with a maximum dimension greater than 6 inches, should not be buried or placed in fills, unless the location, materials, and di sposa 1 methods are speci fi ca lly recommended by the geotechni ca 1 consultant. Oversize disposal operations should be such that nesting of oversize materi a 1 does not occur, and such that the oversize material is completely surrounded by compacted or densified fill. Oversize materials should not be placed within 10 feet vertically of finish grade, within 2 feet of future utilities or underground construction, or within 15 feet horizontally of slope faces, in accordance with the attached detail . 4.3 Import: If importing of fill material is required for grading, the import material should meet the requirements of Section 4.1. Sufficient time should be given to allow the geotechnical consultant to observe (and test, if necessary) the proposed import materials . 5.0 Fill Placement and Compaction 5.1 Fill Lifts: Fill material should be placed in areas prepared and previously evaluated to receive fill, in near-horizontal layers approximately 6 inches in compacted thickness. Each layer should be spread evenly and thoroughly mixed to attain uniformity of material and moisture throughout . 5.2 Moisture Conditioning: b 1 ended, and/ or mixed, content near optimum . Fill soils should be watered, dried-back, as necessary to attain a uniform moisture 5.3 Compaction of Fill: After each layer has been evenly spread, moisture-conditioned, and mixed, it should be uniformly compacted to not less than 90 percent of maximum dry density (unless otherwise specified). Compaction equipment should be adequately sized and be either specifically designed for soil compaction or of proven reliability, to efficiently achieve the specified degree and uniformity of compaction . 5.4 Fill Slopes: Compacting of slopes should be accomplished, in additional to normal compacting procedures, by backrolling of slopes with sheepsfoot rollers at increments of 3 to 4 feet in fill elevation gain, or by other methods producing satisfactory results. At the completion of grading, the relative compaction of the fill out to the slope face should be at least 90 percent . 5.5 Compaction Testing: Field tests of the moisture content and degree of compaction of the fill soils should be performed by the geotechnical consultant. The 1 ocat ion and frequency of tests should be at the consultant's discretion based on fie 1 d conditions encountered. In general, the tests should be taken at approximate intervals of 2 feet in vertical rise and/or 1,000 cubic yards of compacted fill soils. In addition, on slope faces, as a guideline approximately one test should be taken for each 5,000 square feet of slope face and/or each 10 feet of vertical height of the slope . 0-3 •• ... ... .. -.. ... .. ... ... .. ... .. -... 8900881-01 General Earthwork and Grading Specifications (Cont'd.) 6.0 Subdrain Installation Subdrain systems, if recommended should be installed in areas previously evaluated for suitability by the geotechnical consultant, to conform to the approximate alignment and details shown on the plans or herein. The subdrain location or materials should not be changed or modified unless recommended by the geotechnical consultant. The consultant, however, may recommend changes in subdrain line or grade depending on conditions encountered. All subdrains should be surveyed by a licensed land surveyor/civil engineer for line and grade after installation. Sufficient time shall be allowed for the surveys, prior to commencement of filling over the subdrains • 7 .0 Excavation Excavations and cut slopes should be evaluated by a representative of the geotechnical consultant (as necessary) during grading. If directed by the geotechnical consultant, further excavation, overexcavation, and refilling of cut areas and/or remedial grading of cut slopes (i.e., stability fills or slope buttresses) may be recommended . .. 8.0 Quantity Determination ... .. .. .. -.. -... -.. -.. -.. -.. ... .. .. .. For purposes of determining quantities of materials excavated during grading and/or determining the limits of overexcavation, a licensed land surveyor/civil engineer should be utilized . 0-4 .. _________________________________ _ KEY AND BENCHING DETAILS ... -.. -.. -.. .. .. -... -... -.. .. ... -.. -.. -.. -.. -.. -.. .. FILL SLOPE EXISTING GROUND SURFACE - PROJECT 1 TO 1 LINE FROM TOE OF SLOPE l--15' MIN:--! 2' I . LOWEST I MIN. BENCH KEY (KEY) DEPTH CUT SLOPE (TO BE EXCAVATED ?RJOR TO FILL · PLACEMENT) REMOVE UNSUITABLE MATERIAL ---::=-REMOVE UNSUITABLE MATERIAL /_,,/ EXISTING // GROUND // SURFACE--.._,// g / / ~l\y ~ JI CUT SLOPE CUT-OVER-FILL SLOPE / / I, "'~ (TO BE EXCAVATED PRIOR TO FILL PLACEMENT) PROJECT 1 TO 1 LINE FROM TOE OF SLOPE TO COMPETENT MATERIAL ~~:'.:::::::=-REMOVE BENCH UNSUITABLE "MATERIAL .. NOTE: Back drain may be recommended by the geotechnlcal consultant baaed on actual field conditions encountered. Bench dimension recommendations may alao be altered baaed on field conditions encountered. -- ..... ,._ .. .. .. .. .. .. .. ------.. ... .. ... .. ... ... .. ... .. "" .. ... .. .. .. ... .. ... -.. ... ... ----- *NOTE: TRANSITION LOT DETAILS CUT-FILL LOT EXISTING OROUN1:•ce --.,,,,,.,...-----:: ;; -.--MIN. COMPETENT BEDROCK I ,,.-OR MATERIAL EVALUATED_/ I' SY THE GEOTECHNICAL CONSULTANT CUT LOT EXISTING GROUND SURFACE . --------~REMOVE -----UNSUITABLE---.._ ---MATERIAL _..- COMPETENT BEDROCK _/ /QR MATERIAL EVALUATED...----- BY THE GEOTECHNICAL CONSULTANT J__ --- 5•· MIN. ,_ /1;;;:. Deeper or laterally more extensive overexcavatlon and recompactlon may be recommended by the geotechnlcal . consultant based on actual field condition, encountered and location, of proposed Improvement, ... ... ... .. .. -• .. • .. -.. .. • .. • -• ... .. ... • -.. -.. .. .. -... -.. -... RETAINING WALL DRAINAGE DETAIL RETAINING WALL--- WALL' WATERPROOFING PER ARCHITECT'S SPECIFICATIONS---- FINISH GRADE ---""-=-:::t~:::t=::;coMPACTED FILLt::t~::t::t= ·-·--------- SPECIFICATIONS FOR CALTRANS CL.ASS 2 PERMEABLE MATERIAL U.S. Standard Sieve Size 1• 3/4" 3/8" No. 4 No. 8 No. JO No. 50 No. 200 % Passing 100 90-100 40-100 25-40 18-33 5-15 0-7 0-3 Sand Equfvalent>75 SOIL BACKFILL, COMPACTED TO 110 PERCENT RELATIVE COMPACTION* ----¥=-----·Jia• MIN--~-----· :§::§:i=i=i=:§:~-~:. ____ :::-· D ~ O~ ~~iiii;- 0 IS MIN.• ==..,.::::'· FILTER FABRIC ENVELOPE OVE•R~A~ :§:i=~:f (MIRAFI 1-40N OR APPROVED •• O : -Ill EQUIVALENT) .... 1' MIN. ,t-c'z?_.-3/-4'-1·1/2' CLEAN GRAVEL...,. ,4'.(MIN.) DIAMETER PERFORATED =~-.PVC PIPE (SCHEDULE -40 OR EQUIVALENT) WITH PERFORATIONS ORIENTED DOWN AS DEPICTED MINIMUM 1 PERCENT GRADIENT TO SUIT ABLE OUTLET COMPETENT BEDROCK OR MATERIAL AS EVALUATED BY THE GEOTECHNICAL CONSULTANT *BASED OH ASTM 015157 **IF CAL TRANS CLASS 2 PERMEABLE MATERIAL (SEE GRADATION TO LEFT) IS USED IN PLACE OF 3/-4'-1•1/2' GRAVEL, FILTER FABRIC MAY BE DELETED. CAL TRANS CLASS 2 PERMEABLE MATERIAL SHOULD BE COMPACTED TO 110 PERCENT RELATIVE COMPACTION* NO•T TO SCALE ... -------------------:------------, -... -' .. ... ... .. .. .. 1111 -... ... ... ... -... .. ... .. ... .. -.. ... .. .. ... -.. .. .. SIDE HILL STABILITY FILL DETAIL FINISHED SLOPE FACE PROJECT 1 TO 1 LINE FROM TOP OF SLOPE TO OUTSIDE EDGE OF KEY OVERBURDEN OR UNSUITABLE MATERIAL ,, "' 15• MIN. LOWEST BENCH (KEY) EXISTING GROUND ---- SURFACE~ . -->---_,,,..,...-,,,,. / ..,,,,..,,,,✓-~ ~..,,,,.,,,,,..,,.,,✓ .,,,,,.✓/ /., ., // FINISHED CUT PAO PAO OVEREXCAVATION DEPTH ANO RECOMPACTION MAY BE RECOMMENDED BY THE GEOTECHNICAL CONSULTANT BASED ON ACTUAL FIELD CONDITIONS ENCOUNTERED • COMPETENT BEDROCK OR ,,,,,-MATERIAL AS EVALU~TED { BY THE GEOTECHNICAL CONSULTANT NOTE: Subdrain details and key width recommendations to be provided based on exposed subsurface conditions --------------------------------------.J ... ... ... ... .. ... .. .. .. .. .. ... .. .. .. .. .. .. .. .. .. .. .. .. .. -... .. .. .. ... .. .. .. .. .. .. STABILITY FILL / BUTTRESS DETAIL FILTER FABRIC ENVELOPE (MIRAFI 140N OR APPROVED EQUIVALENTI* OUTLET PIPES 4' f4 NONPERFORATED PIPE, 100' MAX. O.C. HORIZONTALLY, 30' MAX. O.C. VERTICALLY SEE T-CONNECTION DETAIL 5$ MJNT 4' MIN. BEDDING SUBDRAIN TRENCH DETAIL NOTES: BACK CUT 1:1 OR FLATTER SEE SUBORAIN TRENCH OETAIL LOWEST SUBDRAIN SHOULO BE SITUATED AS LOW AS POSSIBLE TO ALLOW SUIT ABLE OUTLET ,----10' MIN. PERFORATED L-1....J EACH SIDE PIPE~ . CAP NON-PERFORATED OUTLET PIPE T-CO.NNECTION DETAIL * IF CAL TRANS CLASS 2 PERMEABLE MATERIAL IS USED IN PLACE OF 314'-1•1/2' GRAVEL, FILTER FABRIC MAY BE DELETED SPECIFICATIONS FOR CALTRANS CLASS 2 PERMEABLE MATERIAL U.S. Standard Sieve Size l" 3/4" 3/8" No. 4 No. 8 No. JO No. 50 No. 200 l: Passing 100 90-100 40-100 25-40 18-33 5-15 0-7 0-3 Sand Equivalent>75 For buttreu dlmen1lon1, ••• geotechnlcal reporl/plane. Actual dlmenelone of buttreu and eubdraln ••)'. be changed by the geolechnlcal con1ullant baud on field condltlona • SUBDRAIH INSTALLATION-Subdraln pipe ahould be lnatalled wllh perforallona down u depicted. At locatloaa recommended by th• geotechnlcal, conaullant, nonperforated pipe ahould be lnatalled IUBDRAIN TYPE-Subdraln type ahould be Acrylonltrlle Butadlene Styrene (A.B.S.), Polyvinyl Chloride (PVC) or approved equivalent. Cl••• 1211,SOR 32.11 ahould be uud for maximum fill deptha of 311 fHt • Claaa 200,SDR 21 ahould be uaed for maximum 1111 depth• of 100 feet • .. .. .. .. ... .. ... ... ... .. -.. -.. -... .. .. .. .. .. -... ... ... ... .. -.. -... -.. -.. CANYON SUBDRAIN DETAILS -----EX18'flNQ GROUND SURFAC~ BENCHlllQ 3/4'-1·1/2• CLEAN GRAVEL (9ft.3111. MIN.) e• MIN • COVER SUBORAIN TRENCH SEE BELOW '---8' fJi MIN. ---✓ * IF CAL TRANS CLASS 2 PERMEABLE PERFORATED MATERIAL IS USED IN PLACE· OF PIPE 3/4~1-1/2' GRAVEL, FILTER FASRIC MAY BE DELETED DETAIL OF CANYON SUBDRAIN TERMINAL DESIGN FINISH GRADE SUBDRAIN • • : . ·- t-w-----PERFORATED 5• /6 MIN. PIPE SPECIFICATIONS FOR CALTRANS CLASS 2 PERMEABLE MATERIAL U.S. Standard Si eve Size % Passing l" lOO 3/4" 90-100 3/8" 40-100 No. 4 25-40 No. 8 18-33 No. 30 5-15 No. 50 0-7 No. 200 0-3 Sand Equivalent)75 Sultdraln ahould be conatructed only on competent material aa eveluat•d by the geotechnlcal conaultant. SUBDRAIN INSTALLATION Subdraln pipe ahould be lnatalled with perforatlona down H depicted • At locallona recommended by the geotechnlcal conaultant, nonperforated pipe ahould be lnatalled. SUBDRAIN TYPE-Subdraln type ahould be Acrylonltrlle Butadlene Styrene (A.B.S.), Polyvinyl Chloride (PVC) or approved equlvalent. Clan 1211, SDR 32.5 ahould be UHd for maximum rm depth a of 35 feel. Clau 200, SOR 21 ahould be uaed for maximum flll depth• of 100 feet. ... ... .. ... ... ... .. ... .. .. ""' .. ... .. ... .. ... .. .. .. ... .. ... .. ROCK DISPOSAL DETAIL l'INISH QRAOE SLOPS FACE-- OVERSIZE WINDROW ----., . - DETAIL -------------,,..--:::::;_-- CT~IJ .. TYPICAL PROFILE ALONG WINDROW ... .. ... ... .. .. ... .. -... ... 1) Rock with maximum dimensions greater than 6 inches should not be used within 10 feet vertically of.finish grade (or 2 feet below depth of lowest utility whichever ls greater), and 15 feet horizontally of slope faces, 2) Rocks with maximum dimensions greater than 4 feet should not be utilized in fills . 3) Rock placement, flooding of granular soil, and flll placement should be observed by the geotechnlcal consultant. · 4) Maximum alze and spacing of windrows should be in accordance with the above details Width of windrow should not exceed 4 feet. Windrows should be staggered vertlcally (as depicted) . 5) Rock should be placed In excavated trenches. Granular soil (S.E. greater than or equal to 30) should be flooded in the windrow to completely fill voids around and beneath rocks. ... -----------------------------------' I ,/ I ' I ,, ( ,, I / ' f ', 1 { \ ' ' -; t~ ' I ,I, I I ! ,, ' ,.. , -~~, -c'L .. ,~ ·:: ' I,' l ' • ! ' ' ' .\ \" I I ' \ ' \ \ t ' 1: !. 1 f1.f \ J[) 1:11 " i "" ' . : l , ' 'l ' l l \ -l : ,j ,' l I ! I ,. t I ! . ~ ' ) ' " / ' . ' i ' \ ' ' ,i