The URL can be used to link to this page

Home My WebLink About3299; Home Plant Lift Station; Pump Station North of State St & Carlsbad Blvd; 1987-04-30PRELIMINARY GEOTECHNICAL EVALUATION PUMP STATION, CITY OF CARLSBAD NORTH OF THE INTERSECTION OF STATE STREET AND CARLSBAD BOULEVARD CARLSBAD, CALIFORNIA PREPARED FOR: BILL KOPTIONAK ALMGREN & KOPTIONAK 9968 HIBERT STREET, SUITE 102 SAN DIEGO, CALIFORNIA 92131 APRIL 30, 1987 PROJECT NO. 100239-01 Almgren & Koptionak April 30, 1987 Project No. 100259-01 m m m m Table of Contents Page Site Description 1 Proposed Site Development 2 Field Exploration 2 Laboratory Testing 3 Subsurface Conditions 3 General 3 Fill Soil 3 Santiago Formation: 3 Ground Water 4 Seismicity 4 Regional Seismicity 4 Liquefaction and Dynamic Settlement Potential 5 Discussion, Conclusions and Recommendations 6 Illustrations Figure 1 - Site Location Map Figure 2 - Site plan and Boring Location Map Figure 3 - Lateral and Uplift Pressure Diagrams Table 1 - Seismic Parameters Appendices Appendix A - References Appendix B - Boring Logs Appendix C - Laboratory Testing mm "'"HV Geotechnical Consultants April 30, 1987 Project No. 100239-01 Almgren & Koptionak •* 9968 Hibert Street, Suite 102 San Diego, California 92131 •^ *j Attention: Bill Koptionak Subject: Preliminary Geotechnical Evaluation, Pump Station, City of Carlsbad, North of the Intersection of State Street and Carlsbad Boulevard, Carlsbad, California m Gentlemen: tm m This report presents the results of our preliminary geotechnical investigation of the ^ subject property. The purpose of this study was to evaluate the site materials rel- M ative to the feasibility and design of the planned building. m Site Description «, The subject property consists of a roughly rectangular shaped lot just north of the g| intersection of Carlsbad Boulevard and State Street in Carlsbad, California. The site is relatively level at an approximate elevation of + 15 feet (MSL). A pump — house exists at the south portion of the site. South of the pump house an approxi- mately 15 foot high slope ascends at 2:1 (horizontal to vertical) in a southerly direction (Figure 2, Site Plan). An outlet structure exists at the northern portion of the site, west of boring B-4. Soil Engineering • Geology • Groundwater 10225 Barnes Canyon Road • Suite A-112 • San Diego, CA 92121 • (619)457-0400 Almgren & Koptionak April 30, 1987 Project No. 100239-01 Proposed Site Development The proposed site development will include construction of an underground sewage ^ pump station. Based on preliminary plans and sections (Appendix A), the dry and wet well will be approximately 20 feet deep. A diesel generator room will be ad- «i jacent to the wells, at or close to, existing ground surface. We understand an un- " derground oil tank will be located north of the constructed pump station. We fur- m ther understand that only minor grading will take place, and that the site will re- H main at approximately present grade. Field Exploration Subsurface conditions were evaluated by drilling a test boring (B-l) to a depth of approximately 41.5 feet below existing grade. Four additional shallow borings (B-2 ** through B-5, Figure 2) were drilled to a depth of approximately 5.0 feet below ex- * isting grade to evaluate consistency of the fill material on site. An engineering m geologist was present during the drilling operation to log materials encountered and M to obtain representative soil samples. Borings are presented in Appendix B and the locations are shown in Figure 2. m Sampling from the borings consisted of relatively undisturbed ring samples and stan- ; dard penetration test samples, •f The sampler was driven into the soil with a 140 pound hammer dropping 30 inches. The number of blows required for 12 inches of penetration was noted on the boring m log. if m • 9 m.» Almgren & Koptionak April 30, 1987 Project No. 100239-01 Laboratory Testing tf Laboratory tests were performed on representative soil samples obtained from the — exploratory boring to evaluate engineering characteristics. Laboratory tests in- cluded in-place moisture and density tests, index tests to aid in soil classification, m direct shear tests and a sulfate solubility test. A description of test results is pre- ^sented in Appendix C. m *) Subsurface Conditions «•» m o General Based on our subsurface investigation and our review of the map by Weber, 1982 (Appendix A, Reference 7), the geologic formation present at the site is the Eocene Santiago Formation. Recent man-made fills overlie these deposits. Brief descriptions of the earth materials en- countered are presented below. o Fill Soil Fill soil was encountered in the deep test boring to a depth of ap- proximately 10 feet and to full depth in the four shallow borings. Fill material generally consisted of brown, slightly clayey sand and olive, gray-green well graded sand. In general, the fill material was loose. Based on the four shallow exploratory borings it appears there may be some variations of the fill material. Santiago Formation Underlying the fill, the formational silty sandstone and sandy siltstone with minor amounts of clay of the Santiago Formation were Almgren & Koptionak April 30, 1987 Project No. 100239-01 encountered in boring B-l. In general, the formational materials encountered were very dense. o Ground Water Ground water was encountered at a depth of approximately 10.0 feet below the existing grade in boring B-l. Ground water was encountered in boring B-4 and B-5 at depths of 4.0 feet below existing grade (Figure 2). No ground water was encountered in borings B-2 and B-3. Seismicity o Regional Seismicity No active faults were observed on, or adjacent to the site. The over- all seismic risk is generally considered low. Seismic hazards within the site can be attributed to ground shaking re- suiting from events on active faults. Listed on Table 1 are the faults which can significantly affect the site. The principal seismic considerations for most structures in Southern California are surface rupturing of fault traces and damage caused by ground shaking or selsmlcally-induced ground settlement. The possibil- ity of damage due to ground rupture is considered unlikely since no active faults are known to cross the site. Analyses of the possible earthquake accelerations at the site indicate that the most significant event would be a 6.7 magnitude earthquake located on the Elsinore Fault Zone, which would produce a peak bedrock acceleration of 0.15g at the subject site. Peak accelerations are not, however, representative of the accelerations for which structures are actually designed. Almgren & Koptionak April 30, 1987 Project No. 100239-01 m m The effects of seismic shaking can be mitigated by adhering to the Uniform Building Code and standard practice for seismic design param- eters suggested by the Structural Engineers Association of California. Liquefaction and Dynamic Settlement Potential Research and historical data indicate that saturated loose granular soils are most susceptible to liquefaction. Per recommendations later in this report, the proposed development will rely on the very dense bedrock for support. It is, therefore, our opinion that liquefaction or seismically induced dynamic settlement of the proposed development is unlikely. Cracking due to shaking is not considered a significant haz- ard. No areas within the site were identified as being susceptible to seismically induced landsliding. Site improvements resting on the existing loose surface fills could be subjected to damages should the fill liquefy. If no loads are carried on these improvements, such damages are anticipated to be minor. Almgren & Koptionak April 30, 1987 Project No. 100239-01 DISCUSSION. CONCLUSIONS. AND RECOMMENDATIONS ^1i Discussionm I The geotechnical factors expected to most significantly affect design and construe- ^Pf ^ tion of the proposed development are the high ground water tables and the loose fill overlying the dense bedrock. The bedrock itself is considered a competent *! foundation material and capable of supporting significant loads. The excavation for, and installation of the proposed dry and wet wells will actually result in a net un- ^ loading of the soils at proposed foundation elevation. « <m Of greater significance for design are uplift (or buoyancy) considerations. Uplift t» forces are governed by the relative positions of the ground water level and the bottoms of the underground chamber. For the proposed structure other considera- m tions have set the bottom elevation. Any reduction in uplift forces would therefore depend on lowering the ground water table. Without taking any measures to this effect at this site, prudent design ground water elevation would in our opinion,«•have to be considered to be at finish grade elevation. This situation creates a sub- ** stantial uplift force and high lateral wall pressures. *» m Site location and elevation relative to the ocean (and Mean Sea Level) would make MI complete drainage of the structure impractical, and deep, partial drainage would also severely tax the underdrain system. In our opinion an economical solution™ l| would be to install a perimeter underdrain close to the elevation at which highest ground water level was encountered during this investigation at approximate eleva- tion +11 feet. It would allow the underdrain invert elevation to be used as design ground water elevation in uplift and lateral pressure evaluations. This significantly m reduces the magnitudes of these pressures. Since the drain will be at a relatively ill shallow depth, flow is expected to be low and possibly only periodic. The outflow «t should be tightlined to a suitable outlet facility (or pipe) or, considering the low <i expected volume, even to a rock pocket (French drain) daylighting at a convenient Almgren & Koptionak April 30, 1987 Project No. 100239-01 location. Further discussion and recommendations later in this report are based on this solution. Uplift pressures are resisted primarily by the dead weight of the structure. If the dead weight is larger than the uplift forces, no further uplift resistance measures are required. Methods to provide added uplift resistance, if required, include adding dead weight, and "anchoring" the structure. Dead weight is usually added by increasing structure wall or slab sizes. A combination of anchoring and dead weight increase can be obtained by extending the foundation mat a distance outside the walls to utilize the weight of the soil resting on this and the internal soil fric- tion. Anchoring is usually obtained by installing piers or piles into the underlying bedrock and structurally tying them into the structure. A preliminary uplift evaluation of the proposed underground structure, using esti- mated wall and slab thickness (and hence bottom elevation), indicates that the structure dead weight is relatively close to the uplift forces. Actual figures de- pend on design refinements. It would appear that an economical approach to the uplift design would be to add dead weight. We envision this most conveniently done by thickening the lower portion of the wall or the foundation mat. Cost of additional concrete would to some extent be offset by reduced reinforcing steel re- quirement in the thickened portion. Due to waterproofing on exterior walls (recommended in a later section) we do not consider it prudent to rely on any wall frictional forces when considering uplift re- sistance. The wells should also be taken as empty, and without pumps or mechani- cal equipment installed, when considering uplift. Existing fills, due to their looseness and apparent uncontrolled deposition, cannot be relied on; for structural support for building foundations or flatwork. This affects the proposed diesel generator structure, and requires special foundation considera- tions. Loads should be transferred to the underlying dense formational soils. This can be done either by deep foundations (piers) drilled into the formational soils, by Almgren & Koptionak April 30, 1987 Project No. 100239-01 ^ lowering of a continuous footing or individual footings to bear on the formational S soils, or by overexcavation of fill to the formational soil and construction of a structural fill to finish grade. With the latter option conventional slab-on-grade M floor can be used. The other options should have a structural slab. Selection of the most economical solution depends in part on the approach taken by the con- ^ tractor to the entire well excavation.m *| Conclusions mi The results of our investigation indicate that the proposed construction is feasible di from a geotechnical standpoint, provided the conclusions and recommendations in this report are incorporated into the design of the project and sound construction ^ practices are utilized. The principal concerns that have to be considered for site development have been discussed above. The following section contains our recom- mendations, based on our understanding of the proposed development and the resultsaof this investigation. * Recommendations 4)1 These recommendations are based on current site conditions and our understanding of the proposed construction. If the site is modified by grading or the location of ^ the proposed building is changed, our office should be contacted to review these changes and provide additional recommendations as appropriate. Earthwork Earthwork at the site will consist of excavation for the wet and dry wells, founda- tion excavation, backfill, and minor grading. Grading and earthwork should be per- formed in: accordance with the following recommendations. m Almgren & Koptionak April 30, 1987 Project No. 100239-01 M o Excavation m In our opinion, excavations of the formational material may be accom- ^^A plished with standard heavy excavation equipment. Due to the loose- ness of the overlying fill soil, even shallow excavations should be ^ shored or laid back to 1:1. The option chosen is restrained by adja- cent installations. «» * Drawdown of the ground water during construction is required. Dewa- ^ tering and shoring are addressed in more detail under Construction ii Considerations. — o Fill Placement The on-site formational material and fill soils are generally suitable for use as compacted fill provided they are free of organic material ** and debris. All fill and backfill should be compacted to a minimum ** relative compaction of 90 percent as evaluated by ASTM D1557-78. M The optimum lift thickness for fill soils will be dependent on the type of compaction equipment utilized. Generally, fill should be placed in - uniform lifts not exceeding eight inches. Placement and compaction of fill should be performed in general accordance with the recommendations herein, local grading ordinances, and sound construction practices. 11 jjim Foundations ** m Foundations and slabs should be designed in accordance with structural considera- tions and the following recommendations. In general, a ground water elevation of + j| 11 feet (MSL) should be considered for design. Our tests indicate that the sulphate content of the soil is not high enough to warrant use of Type V Portland cement. Almgren & Koptionak April 30, 1987 Project iNo. 100239-01 Foundation Mat - Wet and dry wells The mat can be founded in the formational materials. Excavation for the proposed construction will actually result in an unloading of the soil at bearing elevation of approximately 1500 psf, which we estimate is less than the design pressure from the construction. As discussed earlier in this report, uplift becomes the controlling factor for design. We recommended that the mat be designed for uplift in accordance with the pressure diagram shown in Figure 3. Final wall and slab thicknesses allow selection of definite design values from this pressure diagram. The thicknesses are related to overall uplift considerations, as discussed earlier. The foundation mat should be waterproofed to withstand the hydro- static pressure and prevent infiltration, using one of several recognized industrial methods. All construction joints should have water stops. Dry and Wet Well Walls We recommend that the dry and wet well walls be designed for lateral pressures represented by the pressure diagram on Figure 3. The exte- rior of all well walls should be waterproofed, as should the wet wall side of the interior wall separating the wet and dry wells. All horizontal and vertical construction joints should have water stops. These measures will minimize ground water infiltration into the wells, and infiltration from the wet well to the dry well. Since experience has shown that some infiltration usually develops even in waterproof underground concrete chambers, it is recommended that the top of the dry well mat be sloped to guide any water from such leakage to a conveniently located sump, from which it can be removed. 10 Almgren & Koptionak April 30, 1987 Project No. 100239-01 *^ leakage to a conveniently located sump, from which it can be g| removed. J o Foundations-Diesel Generatorm ^ In accordance with previous discussions, the loads from the diesel gen- erator structure should be transferred to the underlying formational *i material. We recommend either of three options. Selections of the & most economical is tied to selected method of construction of the «* overall pump facility. Option A: Overexcavation of the loose, existing fill to formational material to 10 feet minimum outside the building line, and replacing with structural fill to grade, installed per recommendation under Earthwork, herein. The proposed building may be supported by conven- tional isolated or continuous footings founded at a minimum depth of ** 18 inches below the lowest adjacent grade. Floor slab may be conven- m tional slab on grade. 4 At a depth of 18 inches, continuous and isolated footings may be de- signed using a maximum allowable bearing capacity of 2500 psf. The — allowable bearing pressure may be increased by one-third when consid- ering loadings of short duration such as wind or seismic forces. Total ^* and differential settlements for footings designed in accordance with the above should be within tolerable limits for this type of construc- "• tion. m ^ Isolated footings should have a minimum width of 24 inches and be 41 reinforced in both directions with a minimum of on No. 4 rebar, top and bottom, for every 12 inches of width or the equivalent. Continu- ^j ous footings should have a minimum width of 12 inches and be rein- forced with at least one No. 4 rebar, top and bottom. 11 Almgren & Koptionak April 30, 1987 Project No. 100239-01 Floor slab should have a minimum thickness of 4 inches and be rein- forced with 6x6-10/10 welded wire mesh placed at midheight in the slab. Concrete shrinkage cracking may be reduced by addition of fiber mesh into the concrete and by careful control of concrete water-to- cement ratios. If moisture sensitive equipment or floor coverings are to be used, we recommend that a moisture barrier (6-mil or greater) be placed beneath the slabs. A two inch sand layer between the slab barrier is recommended to aid in concrete curing. The moisture bar- rier should be underlain by a four inch thick sand layer. Soils under- lying the slabs should be moisture .conditioned prior to concrete place- ment. We recommend that the upper 12 inches of pad grade be soaked to at least 1.2 times optimum moisture content or four percent above optimum moisture content, whichever is greater. Slabs should have crack control joints with appropriate spacing, as designed by the structural engineer. Option B; Supporting the building frame on piers, drilled into the underlying formational material, and connecting the piers with grade beams, on which a structural slab should be designed. Piers should be drilled to 24 inch minimum diameter and extend 10 feet minimum into the underlying foundations! material. Design bearing capacity can be taken at 40 Kips per pier. Option C; Lowering of continuous or isolated footings to bear one foot minimum into the formational material. Extending the walls to grade, or using grade beams, to support a structural slab. At a depth of 12 inches into the foundational bedrock, continuous and isolated footings may be designed using a maximum allowable bearing capacity of 4000 psf. The allowable bearing pressure may be increased by one- third when considering loadings of short duration such as wind or seis- mic forces. Total and differential settlements for footings designed in 12 Almgren & Koptionak April 30, 1987 Project No. 100239-01 accordance with the above should be within tolerable limits for this type of construction. Isolated footings should have a minimum width of 24 inches and be reinforced in both directions with a minimum of one No. 4 rebar, top and bottom, for every 12 inches of width or the equivalent. Continu- ous footings should have a minimum width of 12 inches and reinforced with at least one No. 4 rebar, top and bottom. o Pipe Penetrations Wall penetration for both the gravity feed-line and the force main are below ground water level. Standard "water-tight" penetration design should be utilized. Both gravity feed line and force main are located in the loose fill soil. Proper pipe support should be provided to minimize relative pipe to wall differential settlement, which could cause pipe shearing. This can be achieved by trench overexcavation to the top of the dense bedrock and installing proper bedding to correct invert elevation. Bedding fill should be placed in accordance with recommendations given in earthwork, herein. We also recommend that a pipe joint be located close to the exterior of the well wall. The type of joint should be such that minor relative movement can be accommodated without distress. Underground Fuel Tank We are at this stage in possession only of schematic location of this. We will pre- sent some general recommendations, based on the underground conditions indicated at the well structure. Presuming conditions to be similar at the proposed tank lo- cation, overexcavation to foundation soil is recommended, laying back the slopes to m f—-£g-* ' 13 Almgren & Koptionak April 30, 1987 Project No. 100239-01 _ 1:1. Fill, placed in accordance with the earthwork recommendations herein, should^W jg then be brought up first to the bottom of the tank elevation, later to finish grade. Any flatwork above or near the tank would benefit from the controlled structural , fill and be competently supported. A review of tank excavation/fill versus flatwork location or limits should be made to ensure that structural fill underlies the entire m flatwork. at «« Uplift must be considered when designing for tank support, and if required, the «f tank anchored. This could be to an underlying concrete slab. The groundwater „, could alternatively be lowered locally by installation of perimeter drains at an M elevation sufficiently low for uplift balance purposes. It is assumed that such perimeter drains will be at an elevation that will permit daylighting or direction to•am some other suitable discharge point. ""* Drainage •• «• o Underground Drainage m A perforated underground perimeter drain pipe should be installed — within 2 feet of the dry and wet well at a high point invert elevation + 11 feet (MSL) and at a gradient of 0.5 percent minimum. Free draining granular material should be used for backfill within two feet of the wall, from six inches below pipe invert elevation to approxl- m mately six inches below finish grade. The flow should be tightlined to a convenient discharge point once collected outside the drainage zone. •m — o Surface Drainage «• « The site should be graded so that surface runoff is directed away from the proposed pump facility, collected and directed to a suitable exit device. Gutters and downspouts should be installed on the proposed 14 Almgren & Koptionak April 30, 1987 Project No. 100239-01 diesel generator building, and the water directed to suitable collection swales at least five feet outside the building, and then offsite. Construction Considerations Some, in our opinion, important construction aspects will be addressed in this sec- tion. o Shoring In view of adjacent exis.ting underground piping and site improvements, it is recommended that the shoring of the well excavation be carried to full height on the south, east, and west sides. At the north side, excavation to formational soil In the diesel genera- tor building, if this foundation option is selected (Option A, described earlier), would allow shoring the well excavation only in the lower, formational soil portion. It would also give a lower access point to the well excavation. The generator building excavation should be shored full height, or laid back at 1:1, if sufficient room exists. o De watering There is, in our opinion, no practical method of sealing out the ground water during construction. Dewatering of the excavation will there- fore, be necessary during construction. This can be carried out by drilling wells outside the excavation limits and installing pumps, and start drawing down the water level prior to excavation taking place. Dewatering can also be achieved from a deepened sump inside the ex- cavation, as the latter descends. The least messy of the two dewa- tering methods is the pre-construction well installation, both in terms 15 Almgren & Koptionak April 30, 1987 Project No. 100239-01 of the turbidity of the water pumped, and the handle-ability of exca- vated material. By drawdown of the general ground water, the effective stress in- creases in the areas surrounding the well or sump. Due to the loose- ness of the fill, minor settlements in these areas are likely. Some allowance for restoration should therefore be made in budgeting the project. o Method of Wet and Dry Well Excavation A contractor's approach to the excavation could affect the selection of the most economical generator building foundation scheme. It is recommended that potential candidate contractors opinions on this matter be sought prior to issuing contract documents and drawings. Construction Observation The recommendations provided in this report are based on subsurface conditions dis- closed by our subsurface investigation. The interpolated subsurface conditions should be checked in the field during construction. We recommend that final pro- ject drawings be reviewed by our office prior to construction so that construction is in accordance with our recommendations. We recommend that all footing excavations be observed by a representative of our firm, and that testing and observation of fill placement be performed by a repre- sentative of this firm to evaluate compliance with the recommendations provided in this report. The field. Investigation, laboratory testing and geotechnical analysis presented In this report have been conducted in accordance with current engineering practice. Our observations are based on test borings located across the site and our recommenda- 16 Almgren & Koptionak April 30, 1987 Project No. 100239-01 tions reflect interpolated conditions between the test excavations. Variations may exist and conditions not observed nor described in this report may be encountered during construction. If conditions different from those described in this report are encountered, this office should be notified and additional recommendations, if appli- cable, will be provided upon request. We appreciate this opportunity to be of service, and if you should have any ques- tions regarding this matter please contact this office. Very truly yours, NINYO & MOORE Beth S. Abramson Project Senior Staff Geologist m ma m m Jan A. Dahlgren Associate Engineer Roy E. Moore, REC 28119 Principal BSA/JAD/REM/eg Distribution: (2) Addressee m a 17 e Carlsbad-Beach State Park \ "\ REFERENCE: 1986 Aerial Foto-Map Book. 2OOO Scale In Feet 4000 NORTH m m m SITE LOCATION MAP CITY OF CARLSBAD PUMP STATION FACILITY CARLSBAD, CALIFORNIA PROJECT NO. 100239-01 DATE 4/10/87 FIGURE 1 LEGEND B-5 Indicates approximate location W of exploratory borings REFERENCE: JAYKIM ENGINEERS, inc. 8865 BALBOA AVENUE SAN DIEGO, CALIFORNIA "CITY OF CARLSBAD HOME PLANT SEWER STATION SITE PLAN /?/? 26363 DRAWING NUMBER: 257-3"Approximate Scale in Feet SITE PLAN AND BORING LOCATION MAP CITY OF CARLSBAD PUMP STATION FACILITY CARLSBAD, CALIFORNIA PROJECT NO, 100239-01 DATE 4/10/87 FIGURE 2 Finished grade Drain invert elevation plus 1 1 (msl) V /I /I Bottom of Mat Elevation Perimeter Drain \ \ <- 60.Y PSF k 62.4X X PSF \ \ \ \L \j. \ XPSF ASSUMED CONDITIONS 1. At rest conditions Ko equals 0.5 2. Ysoil (moist) equals 120 PCF 3. Ground water at perimeter underdrain invert elevation NOT TO SCALE LATERAL AND UPLIFT PRESSURE DIAGRAMS CITY OF CARLSBAD PUMP STATION FACILITY CARLSBAD, CALIFORNIA PROJECT NO. 1002 39-O1 DATE 5/1/87 FIGURE 3 Almgren & Koptionak April 30, 1987 Project No. 100239-01 m m m m TABLE I SEISMIC PARAMETERS FOR ACTIVE FAULTS Maximum Probable Earthquake Fault San Andreas Elsinore San Jacinto Newport- Inglewood Coronado Banks *Rose Canyon Approximate Distance From Fault To Site (Miles) 70 24 48 52 20 14 Maximum Credible Earthquake Richter Magnitude 7.5 7.5 7.5 7.0 7.5 7.0 Richter Magnitude 7.5 6.7 7.2 6.5 6.0 6.5 Peak Bedrock Acceleration (Gravity) .07 .17 .08 .03 .12 .23 **Repeatable High Ground Acceleration (Gravity) .07 .17 .08 .03 .08 .15 * This fault is considered "potentially active," based on our current knowledge of the geologic conditions of the San Diego County area. ** The repeatable high ground acceleration may be taken as 65% of the peak acceleration for sites within 20 miles of the epicenter (after Ploessel and Slossen, 1974). Almgren & Koptionak April 30, 1987 Project No. 100259-01 j APPENDIX A References«l - 4 1. Almgren & Koptionak: unpublished, undated sketches, received April 22, <H 1986. Location, marked on 1:10 Part Plan (Ref. J), Schematic |J Sections and Isometric Views, 2 pages. j 2. Borchardt, G. and M.P. Kennedy, 1979, Liquefaction Potential in Urban * . San Diego in California Geology. «H «i 3. City of Carlsbad Engineering Department, Home Plant Sewer Station Site Plan, Project No. 6/M9, Drawing No. 257-3, (undated).m «4. Greensfelder, R.W., 1974 Maximum Credible Rock Acceleration from „, Earthquakes in California Division of Mines and Geology, Map Sheet 23. Ml "* 5. Lee, L.J, 1977, Potential Foundation Problems Associated with Earth- w quakes in San Diego jn Geologic Hazards in San Diego. •m — 6. Ploessel, M.R., and Slossen, J.E., 1974, Repeatable high ground accel- erations from earthquakes, important design criteria: California m Geology V. 27, p. 195-199. 0 7. Weber, F.H. Jr., 1982, Recent Slope Failures, ancient landslides, and """ related geology of the north-central coastal areas San Diego — County California: C.D.M.G., OFR 82-12LA Aerial Photographs Source Date Scale Flight Numbers B-W 1953 1:24,000 AXN-14M 20 and 21 APPENDIX B MAJOR DIVISIONS COARSE GRAINED SOILS(Mor« thin MZ ol »oll > no. 200 stove »(z«)FINE GRAINED SOILS 1tMore thin 1/2 ol toll < no. 2OO »l«v» alz*) |GRAVELS (More thin 1/2 ol coarea friction ]> no. 4 tlive alze) SANDS (More thin 1/2 ol coin* friction <^ no. 4 ileve ilzt) SILTS & CLAYS LL< 50 SILTS & CLAYS LL>50 HIGHLY ORGANIC SOILS SYMBOLS GW GP GM GC SW SP SM SC ML CL OL MH CH OH Pt TYPICAL NAMES WtR grided grtvete or grsvel-tand mixture*. Ittt* or no fine* Poorly gridid graval* or griv»(-»ind mixtures, little or no flnti Sllty grivili. grivet-und-illt mlxturis Cliyiy grsvels, grsveHssnd-clsy mixture* Will grided iindi or grivilly ssnds. little or no fln«i Poorly gridid iindi or grtvslly iindi, llttl* or no finis Sllty unds, iind-*llt mixtures Cliyty unds, ssnd-clsy mlxturss Inorginle lilts tnd very fin* isnds, rock flour, illty or cliy«y fin* isnds or ctsycy lilts with sXght plsstlelty Inorgtnlo clsys ol low to mtdlum plsstlelty. gnv.lly elsys. • sndy clsys. tllty clsys, Issn elsys Organic lilts snd orginto sIKy elays ol low pUitterly Inorginlc lilts, mtc«c«oul or dlstomsc*ous (In* ssndy or *llty lolls, •little lilts Inorginlo olsys pt high plsitlctty. 1st elsys Organic clsy* of medium to high plsstlelty, orginkj illty elsys, organic silts Peat snd other highly orgsnle soil* CLASSIFICATION CHART (Unified Soil Classification System) CLASSIFICATION BOULDERS COBBLES GRAVEL coarae line SAND coarie medium fine SILT & CLAY RANGE OF GRAIN SIZES U.S. Standard Sieve Size Above 12" 12" to 3" 3" to No. 4 a" u 1/4" a/4" i« N*. 4 No. 4 to No. 200 N*. 4 1* H«. 10 H». 10 10 N*. 40 N*. 40 10 M«.200 Below No. 200 Qrsln.SIze In MIIHmaters Above 30S 306 to 78.2 76.2 to 4.76 rs.a to 11.1 1S.1 t» 4.7* 4.76 to 0.074 4.7S to S.OO 1.00 U 0.410 0.410 U 0.074 Below 0.074 30 " 40•of >« £ 30_u •oa.— 20 a. 10 0 S /\s / /Z^ti.-Wi'/P / \ ML y/ CL yXS^ / J / ML ft OL S 1 y CH x iS MH ft _S^ / OH GRAIN SIZE CHART 10 20 SO 40 30 60 70 80 LL (Ll«iild Limit), % PLASTICITY CHART U.S.C.S. METHOD OF SOIL CLASSIFICATION 1H •I n HOLE PIAMFTFR D^TE DRii i En npop BORING NO, nnn i iwr, r.o TYPP OP RIR PI FV TOP OF HOI F DRIVE WEIGHT i(— i-Q. UJUl UJQ U. 0 — 5 — 10 - 15 - 20 — - - * 25 - 30 — mm* <j X 19 ^ iK (9 •Q _» • — '0 -. 0 . — o "~— ^-T U" — . - ~_7_" -T7^-T_ ¥ UJo3 5 fc0« CO ljQ.s i "> t o Q£_l Ul CD Q. 1 | 14 rr> . 7- 8.5' - •« - - " - 15 >*W i— in>ZU.KUJUQQQ. 106.2 (86.4) \\_ ior § ^ §| m 2 U 14.9 •c. co"> — ^ wSd3 .^ •in GEOTECHNICAL DESCRIPTION I OGGED BY DATE BACKFILLED — - Undisturbed Drive Sample - Number to left represents sample number - Percent of Maximum Density r Bulk Sample LI • Standard Penetration Test (Split-Spoon Sampler) Graphic Log : r-i-J. silt ••:•.'• sand "~~- clay ^»* caliche pods ^S* caliche stringers ° clast ^y^ cemented zone f. Jk root hairs <^> clay rip-up clasts heavy mineral laminae <g> pockets of gravel ™" 9 seepage _S- groundwater table T.D. = Total Depth Backfilled 11/6/86 - BORING LOG PROJECT NO. DATE PLATE NO. Explanation of Small-Diameter Boring Log _ 41VLL Z &O 5- 15- COLD O.S co m ~ c n - o0 LL CO O CO _H 8 ~flJjum~m 4 ~1 If 6nif] 3 J 1 18 -ITln -t 4-i i| 65 5% 1 ~ HIoc COo S 12.1 24.8 16,5 23.7 17.8 25.4 27.6 oa H 111a a:a 90.1 99.8 101.7 98.5 103.5 o 5 °? 1 = 0 SC sc-sw sw+sc SW-SM SC sc+sw 1 DATE DRILLED 3/23/87 BORING NO. l GROUND ELEVATION 15'~ (MSL) SHEET 1 OF 3 METHOD OF DRILLING Geodrill DRIVE WEIGHT 1^0 Ibs. DROP 30" SAMPLED BY BS^ LOGGP" Ry BSA DESCRIPTION FILL: @ 0.0': Brown, moist, loose, slightly clayey sand. @ 1.5': Mottled brown, moist, loose, slightly clayey sand and olive green, moist, loose, fine to coarse-grained sand; some coarse quartz grains. @ 2.0': Mottled olive gray, very moist, loose, fine to medium grained sand with occasional brown, clayey sand; decrease in brown, clayey sand with increased depth. @ 5.0': Olive gray green and lesser orange gray, very moist, loose, fine to medium-grained sand; some dense chunks. @ 6.5': Olive gray brovn, very wet, loose, clayey, fine to medium-grained sand. @ 8.0': Olive gray, wet, loose to dense, clayey, fine to medium-grained sand; some silt, chunks of brown, clayey sand at approximately 8.0 feet. @ 9.0': Olive' gray 'green, wet to saturated, dense, fine to medium-grained sand. FORMATION : @ 10.0': Gray, olive green, saturated, dense, silty, fine- grained sandstone; very homogenous. @ 14.0': Yellow brown, saturated, very dense, slightly clayey. silty, fine-grained sandstone. . BORING LOG ^^JjjImmalfmJ "yl^^JlJl W^^ Carlsbad Pump Station F «^ f City of Carlsbad PROJECT NO. DATE 100239-01 3/23/87 FIGURE B-1 «* *) **4 ni DEPTH (Feel)9O 25- 30- Q C_| SAMPLES"5CO Driven1 CLOWS/FOOT50/4 5°/5 82 MOISTURE (%)27.7 17.3 15.0 DRY DENSITY (PCF)CLASSIFICATIONU.S.C.S.DATE DRILLED 3/23/87 GROUND ELEVATION 15'~ (MSL) METHOD OF DRILLING DRIVE WEIGHT 1^0 Ibs SAMPLED BY &SA BORING NO. 1 SHEET 2 OF 3 Geodrill in"DROP JU LOfifjpn RV BSA DESCRIPTION @ 23.0': Gray green, very dense, fine to coarse-grained sandstone; minor amounts of clay. @ 30.0': Green to green gray, very dense, slightly silty, fine to medium-grained sandstone; minor clay, probably associated with altered feldspars. @ 35.0': Dark green gray, with spotted orange-brown, iron oxides, very dense, slightly clayey, sandy silt- stone. . BORING LOG_/V//7^/yi lpore__ PROJECT NO. 100239-01 Carlsbad Pump Station City of Carlsbad DATE 3/23/87 FIGURE B-2 *n * * <m 4 doQU. 3! 2. UO dn 45- 50- 5- /u ••I </u 5K; (/ 3 ,j > c <u> Q m *\ oOLL\(fi 5 u 5°/4 i •<// ? UJ CCD co O2 14,8 »w 0 D. ^. H UQ CCa r&& op §S I'J< o JB jmsy\ DATE DRILLED 3/23/87 BORING NO. ! GROUND ELEVATION 15'~ (MSL) SHEET 3 OF 3 METHOD OF DRILLING Geodrill DRIVE WEIGHT l^u lbs • DROP ^^ CAMPLED BY B^A LQGGFO PY B^A DESCRIPTION @ 40.0': Light brown, very dense, medium to coarse-grained sandstone; altered feldspars. Total Depth @ 41.5 feet Groundwater @ 1Q.O feet BORING LOG C%€|%l^^h Carlsbad Pump Station * ^««i City of Carlsbad 100239-01 " 3/23/87 FIGURE 3.3 DEPTH (Feet)10- 15- on—- SAMPLES£ 3 DrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)0 _i0 DATE DRILLED 3/23/87 BORING NO. 2 GROUND ELEVATION SHEET OF METHOD OF DRILLING Geodrill DRIVE WEIGHT 140 Ibs. DROP 30" SAMPLED BY BSA I nr:r;pD BY BSA DESCRIPTION FILL: Orange brown, slightly clayey sand; clayey areas are darker brown. Total depth @ 5.0 feet. No ground water encountered. -W>y*w BORING LOG l\j%j |[ %j Carlsbad Pump Station ^™" City of Carlsbad PROJECT NO. DATE ,-,^,,r.^100239-01 3/23/87 FIGURE B_4 0 0)u. ir LU Q 10- 15- ••• 0u 5 «: (/ 3 rj 1J • O> Q ,J| 1 o0u.X(/) 5 a i ^< ^ b° LU CCD 1- W Os »«» oQ. >• U > CCQ w& 0 (_ S3 *3 3o . A myy\ DATE DRILLED 3/23/87 BORING NO. 3 GROUND ELEVATION 15 ~ SHEET 1 OF l METHOO OF DRILLING Geodrill DRIVE WEIGHT 1^° lbs • DROP 30" SAMPLED BY B^^ ' <">GGEQ BY B^^ DESCRIPTION FILL: comment that drilling is hard. Total depth @ 5.0 feet. No ground water encountered. BORING LOG |1J 1J 1~ IS ^ „ - Carlsbad Pump Station City of Garish^ PROJECT NO. DATE .-,«.,.,,- 100239-01 3/23/87 | FIGURE B_5 ~. ou. X Q.ut Q 10- 15- ••I 0u 5*: (/ | ,J •) O> Q m 1 oou.xV)5 a , mi /t j2 Uc: 01 O S > _ «» Oa. >•t u ^>-irQ Y/A zgp S^13< o ji ^yyi DATE DRILLED ^/?^/87 ROBING NO. 4 GROUND ELEVATION IS'^ SHEET 1 OF 1 METHOD OF Dh.iLLING Geodrill DRIVE WEIGHT 140 Ibs . DROP 30" CAMPLED BY BSA i OGGED BY BSA DESCRIPTION FILL: Orange brown, slightly clayey sand. @ 4 ' : color change to gray blue. Total depth @ 5.0 feet Ground water @ 4.0 feet. BORING LOG i(%(%l[*Ch [**»*• **«••• Carlsbad Pump Station C~it"y nf flarlsh^H 1P0R0°2J3E9C-T0N10- " 3y2A3^87 FIGURE B-6L_ iH ««l m m m m ^ooLL. r c^ UJQ 5 - 10- 15- 20 ••• </n a2 V 3 UJ ,t )1i o> Q m 1 f-oOLL w5 _ia 1 ^< ^ b" 111cco V)o »^ oQ. >• (/5s >cc Q Y/A zo^zs^ 13 5o • j|yyi DATE DRILLED 3/23/87 BORING NO. ^ 15'- 1 1GROUND ELEVATION SHEET OF METHOD OF DRILLING Geodrill DRIVE WEIGHT ° lbs * DROP 30 SAMPLED BY I.OGOEP BY BSA. DESCRIPTION FILL: Orange brown, slightly clayey sand. @ 4 ' : Dark brown, slightly clayey, medium- grained sand. Total depth @ 5.0 feet. Ground water @ 4.0 feet. BORING LOG iQOl ^ Carlsbad Pump Station ' ^mm City of Carlsbad PROJECT NO. DATE ci^noe100239-01 3/23/87 rHaUKE B_7 Almgren & Koptionak April 30, 1987 Project No. 100259-01 APPENDIX C Laboratory Testing «H Classification Mi Soils were visually classified in accordance with the Unified Soils Classification Sys- tem. Soil classifications are indicated on the boring logs in Appendix B. In-Place Moisture and Density Tests The moisture content and dry density of relatively undisturbed samples obtained from the exploratory excavations were evaluated in general accordance with ASTM D-2216. The test results are presented in the boring logs Appendix B. Particle - Size Analysis An evaluation was performed on selected representative soil samples in general ac- cordance with ASTM D422-63. The grain-size distribution curves are presented in Appendix C. These test results were utilized in evaluating the soil classifications in accordance with the Unified Soil Classification System. Direct Shear Test A direct shear tests were performed on both disturbed and remolded samples in general accordance with ASTM D3080-72 to evaluate the shear strength characteris- tics of selected materials. The samples were inundated during shearing to repre- sent adverse field conditions. 4000 3000 HIe 2000 lil CO 1000 1000 2000 3000 4000 5000 NORMAL STRESS (PSF) Description Symbol o Boring Number B-l Sample Number Depth (Feet) 8.5 - 9.0 Cohesion (PSF) 100 Friction Angle 24 Soil Type SC + sw DIRECT SHEAR TEST RESULTS Carlsbad Pump Station City of Carlsbad PROJECT NO. 100239-01 DATE 4/22/87 FIGURE C-l 3000 {7*U. a wU onnficcfe a: tuxo i Ann 0 . / A .w // ( ^ •^• '^ / (, ^ ^ ^* /^ /^ /^ ''^ / ^I / ? /^ gi ^/0 f t s/*K*1 / J 1* 1000 2000 3000 4000 5000 NORMAL STRESS (PSF) Description Symbol B-l Boring Number 3 Sample Number Depth (Feet) 5.5 - 6.0 Cohesion (PSF) 320 Friction Angle 36.5 Soil Type DIRECT SHEAR TEST RESULTS Carlsbad Pump Station City of Carlsbad PROJECT NO. 100239-01 DATE 4/22/87 FIGURE C-2 "If III SAMPLE B-l 7 10 - 11.5 DILUTION 1.1 READING PPM 110 % SULFATES .0110 POTENTIAL DEGREE OF SULFATE ATTACK Negligible « m * I SOLUBLE SULFATE TEST RESULTS Carlsbad Pump Station City of Carlsbad PROJECT NO. 100239-01 DATE A/22/87 FIGURE C-3 100 90 I 80 UJ _ _ite f O co 60 a: £ 50 "• 40 S 30 0 S 20 0. 10 n GRAVEL Coor»e 1 Fine SAND Cor.Medium Fine FINES (Silt or Cloy) U.S. STANDARD SIEVE NUMBERS HYDROMETER S* 1-1/2" 5/4" S/V 4 10 20 40 SO IOO 200 ' ••• M»«• "^>$\ \ 11 1 I \ S v ", 50 10 0.9 0.1 0.09 GRAIN SIZE IN MILLIMETERS 0.01 0.009 0.001 0.000! SYMBOL BORING NUMBER B-l SAMPLE NUMBER DEPTH (FEET) 3% - 5 LIQUID LIMIT PLASTIC LIMIT PLASTICITY INDEX SOIL TYPE SW+ sc IOO 90 N * TO fa 60 £ 50 "• 40 5 30u £ 20 Q, 10 n GRAVEL Coarse 1 Fine SAND Cor.Mediu n Fine FINES (Silt or Clay) U.S. STANDARD SIEVE NUMBERS HYDROMETER 5" t-l/2" 3/4' 3/V 4 10 20 4O SO IOO 200^ •^>, 1S ^,, 90 10 I 0.9 O.I 0.09 GRAIN SIZE IN MILLIMETERS 0.01 0.009 0.001 0.0001 SYMBOL BORING NUMBER B-l SAMPLE NUMBER DEPTH (FEET) 8.5 - 9 LIQUID LIMIT PLASTIC LIMIT PLASTICITY INDEX SOIL TYPE SC+ sw GRADATION TEST RESULTS Carlsbad Pump Station City of Carlsbad PROJECT NO. 100239-01 DATE 4/87 FIGURE C-4 100 90 I 80 * 70 a 60 K £ 50 1 40 5 30u £ 20a. 10 n GRAVEL Coorie 1 Fine SAND Cor.Medium Fine FINES (Silt or Clay) U.S. STANDARD SIEVE NUMBERS HYDROMETER J" 1-1/2" 3/4' S/V 4 10 20 *0 60 100 300 • -*•<V s \ t V t\\\1 50 10 I 0.5 0.1 0.05 GRAIN SIZE IN MILLIMETERS 0.01 0.005 0.001 0.0001 SYMBOL BORING NUMBER B-l SAMPLE NUMBER DEPTH (FEET) 15.5-17 LIQUID LIMIT PLASTIC LIMIT PLASTICITY INDEX SOIL TYPE 100 90 i 8° w -./»* 70 m 60 or ^ 50 ^ 40 5 30o £ 20 0. 10 n GRAVEL Coarse I Fine SAND Cor.Medium Fine FINES (Silt or Clay) U.S. STANDARD SIEVE NUMBERS HYDROMETER t* 1-1/2" 3/4" S/J" 4 10 20 40 60 100 200 , >X VK S, \ " ~\s s s ^•^ , 50 10 I 0.5 0.1 0.05 GRAIN SIZE IN MILLIMETERS 0.01 0.005 0.001 0.0001 SYMBOL BORING NUMBER B-l SAMPLE NUMBER DEPTH (FEET) 35-36.5 LIQUID LIMIT PLASTIC LIMIT PLASTICITY INDEX SOIL TYPE GRADATION TEST RESULTS Carlsbad Pump Station City of Carlsbad PROJECT NO. 100239-01 DATE 4/87 FIGURE C-5