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Home My WebLink About; Squires Reservoir; Soils Report; 1988-09-09PRELIMINARY GEOTECHNICAL INVESTIGATION FACILITIES EXPANSION FOR SQUIRES RESERVOIR COSTA REAL MUNICIPAL WATER DISTRICT CARLSBAD, CALIFORNJA PREPARED FOR: MR. STEVE DEERING LUKE-DUDEK CIVIL ENGINEERS 605 THIRD STREET ENCINITAS, CALIFORNIA 92024 SEPTEMBER 9,198s PROJECT NO. 100743-01 Luke-Dudek September 9,198s Project No. 100743-01 Table of Contents El@ Scope of Services ................................................................................................................... 1 Site Description.. ................................................................................................................... 2 Proposed Development ........................................................................................................ 2 Subsurface Investigation and Laboratory Testing.. .......................................................... 4 Geology and Subsurface Conditions .................................................................................. 5 Conclusions and Recommendations .................................................................................. 8 Recommendations for Earthwork.. ........................................................................ 8 Recommendations for Concrete Storage Tank.. ............................................... .10 Recommendations for Pump Station.. .................................................................. 12 Recommendations for Pipeline Alignment.. ....................................................... 14 Recommendations for Chlorination Building Expansion.. ............................... 15 Recommendations for Bulk Storage Tanks.. ....................................................... 17 Illustrations Figure 1 - Site Location Map Figure 2 - Adjusted Modulus of Subgrade Reaction Figure 3 - Tank Underdrain Detail Figure 4 - Retaining Wall DrainDetail Table 1 - Seismic Parameters for Active Faults Plate 1 - Site Plan Armendices Appendix A - References Appendix B - Boring and Test Pit Logs Appendix C - Laboratory Test Results Appendix D - Seismic Traverse Results i &t m ame Gec’technlcai Corwranti September 9,198s Project No. 100743-01 Luke-Dudek Civil Engineers 60.5 Third Street Encinitas, CA 92024 Attention: Mr. Steve Deering Subject: Preliminary Geotechnical Investi ation, Facilities Expansion for Squires 8 eservoir, Costa Real Municipal Water District, Carlsbad, Califorma Gentlemen: In accordance with your request, we have performed a preliminary geotechnical investiga- tion at the site of the proposed facilities expansion for Squires Reservoir in Carlsbad, Cali- fornia (Figure 1). The purpose of our study was to evaluate the geotechnical conditions at the site as they pertained to the proposed concrete storage tank facility, pump station, pipelines, bulk storage tank facilities, and expansion of the existing chlorination building. This report presents our findings, conclusions, and recommendations regarding the pro- posed facilities expansion at the subject site. Scope of Services The scope of our services included the following: 0 Review of the referenced geotechnical literature, project drawings, and aerial photographs. (Appendix A). 0 Site visit and geologic reconnaissance. 0 Field work for eight seismic traverses located generally within the limits of the two alternative pipeline alignments and one of the alternative tank site . Soil Engineering l Geol~ . Groundwater IO225 Barnes Canyon Road l Suite A-112 l San Diego. CA 92121 l (619) 457-0400 r - Luke-Dudek September 9,198s Project No. 100743-01 0 Excavation, sampling, and logging of twelve exploratory test pits and seven exploratory borings. 0 Laboratory testing of selected soil samples. 0 Geotechnical data analysis and engineering design for the proposed construc- tion. 0 Preparation of this report presenting our findings, conclusions, and recom- mendations regarding the proposed facilities expansion. Site Descriution The site of the proposed construction consists, generally, of the eastern side of a southerly trending canyon which terminates to the north of the existing Squires Reservoir site and is truncated to the east by the Squires Reservoir embankment. The canyon wall is composed primarily of natural soils at grade, with some grading having taken place to construct the access roads and building pad for the existing chlorination building. Access roads leading to the existing facilities extend generally along the bottom of the canyon. Minor fills for the access roads and the building pad for the chlorination building appear to have been con- - strutted utilizing on-site fill materials. The canyon wall, as well as the face of the reservoir embankment, are moderately to sparsely vegetated with natural vegetation. The existing topography and general site conditions are depicted on Plate 1. wsed Development The proposed site development consists of a a ten million gallon concrete water storage tank, a pump station and pipelines provided for the movement of water from the reservoir inlet/outlet pipe through the pump station to the storage tank and back again. The devel- opment also includes expansion of an existing chlorination building and construction of two bulk storage tank sites. The locations of the planned construction are shown on Plate 1, and a brief description of each area of the development is provided below. The ten million gallon rectangular concrete water tank will be located at the northern ter- minus of the canyon generally west of the north reservoir embankment abutment. This tank will be founded in formational materials and will be buried on all four sides by fill r 2 e c - - I Luke-Dudek September 9,198s Project No. 100743-01 slopes to be constructed as part of the development. We understand that the tank will be approximately 62,000 square feet in area, measuring 240 feet by 260 feet by 26 feet high. The tank will be constructed with a 14 inch thick reinforced concrete mat foundation, side- walls, internal multiple baffles and 8 inch thick top. The tank will be founded at an eleva- tion of approximately 485 feet M.S.L. which will require an excavation into the natural ma- terials ranging in depth from approximately 5 to 20 feet. The pump station is to be located south of the tank site, generally west of the toe of the ex- isting reservoir embankment. The pump station will be situated in the eastern portion of an excavation made into an existing natural knoll just north of the chlorination building. The pump station will be founded at approximately the existing elevation of the adjacent access road with cut slopes up to 25 feet in height on the north and east sides of the struc- ture. The proposed structure will be constructed utilizing reinforced concrete. The pumps and motors will be situated on a pad directly west (in front of) the proposed structure. We understand that fill will be placed against the lower 8 to 10 feet of the walls at the toe of the cut slopes adjacent to the north and east sides of the structure. Borings will be drilled for the pump shafts which will extent a maximum of IO feet below the finish pad grade. The pipelines which will transport water from the inlet/outlet pipe for the Squires Reser- voir, through the pump station, to the concrete storage tank and back, will be placed in an excavation approximately 7 feet below the existing grade following the existing site con- tours. We understand that the trench excavations for the pipeline will be approximately 14 feet wide, and that the pipeline will be entirely buried at all locations. The pipelines will consist of dual 42 inch diameter pipes, laid side by side, and will be tied into the in- let/outlet pipe for the Squires Reservoir, and the pumps at the pump station. The pipes will extend below the bottom of the tank at a maximum depth of 10 feet, and will access the tank bottom near the center. The proposed expansion of the chlorination building will be constructed on the existing fill pad, adjacent to the west sides of the building. Only minor remedial earthwork is antici- pated to prepare the pad site for the building expansions. We understand that the new 3 structure will be constructed using similar materials and construction design as those used in the original chlorination building. Luke-Dudek September 9,198s Project No. 100743-01 Two bulk storage tank sites have been identified. One on the building pad west of the chlo- rination building approximately 10 feet east of the west side of the fence enclosure. The second tank will be located on a fill pad to be constructed, generally, south of the concrete storage tank. Both tanks will be founded on grade in fill materials utilizing isolated foun- dations. The tanks will be constructed of steel and will be cylindrical in configuration rest- ing on two or more “saddles”. S ubg surface Inv _ Testin On May 17, 1988, representatives of our firm performed eight seismic traverses at the sub- ject site. One of the traverses (T-8) was located adjacent to the area of the westernmost of the two proposed tank sites. The remaining seismic traverses were located generally along the two alternative pipeline alignments. Prior to commencement of the exploratory exca- vations, the easternmost alternative tank site and the alternative pipeline alignment along the access road were eliminated from consideration. The exploratory excavations were made on July 26 and 27, 1988, and consisted of drilling four borings at the proposed tank site, one boring at the proposed pump station site, one boring at the proposed bulk storage tank site adjacent to the chlorination building, and one boring south of the existing chlorination building. One exploratory test pit (IF-l) was ex- cavated within the limits of the proposed tank site to correlate data obtained from an ex- ploratory boring. One test pit (TP-2) was excavated within the area of the proposed fill pad just south of the tank site. Nine test pits were excavated generally along the alignment of the proposed pipeline and one test pit (TP-9) was excavated near the northeast corner of the proposed pump station. c The purposes of all excavations were to observe the geotechnical conditions at those sites, to log and obtain representative soil samples and to evaluate the depth to non-rippable granitic bedrock. Undisturbed soil samples were obtained only from borings B-6 and B-7, - ,- Luke-Dudek September 9, 1988 Project No. 100743-01 which were located within the fill pad for the existing chlorination building. Bulk samples were obtained from each of the borings and the test pits excavated at the site. The ap- proximate locations of the borings and test pits are shown on Plate 1. Test pit and boring logs are presented in Appendix B. Laboratory tests performed on representative soil samples obtained from the exploratory excavations included evaluation of maximum density, in-situ moisture and density, grain size distribution analysis and soil type classification. Results of the laboratory tests are pre- sented in Appendix C and on boring logs B-6 and B-7, in Appendix B. The results of the seismic traverses are presented in Appendix D. Based on our subsurface investigation, site reconnaissance and review of the referenced lit- erature, the site appears to be underlain by fill, decomposed granitic bedrock and granitic bedrock. Some alluvium is likely to be present in the drainage chamrels on the site, but alluvium was not observed in our excavations. Detailed descriptions of the observed on- site soil units appear on the boring logs and test pits in Appendix B. Generalized descrip- tions of the units observed during our investigation are presented below in order from old- est to youngest: Granitic Bedrock The granitic bedrock on the site is part of the Cretaceous Southern Califor- nia Batholith in the Peninsular Ranges Geomorphic Province. Our excava- tions indicate that, at depths ranging from 5.5 to an excess of 20 feet, these rocks become very competent. At shallower depths, these rocks are typically weathered or decomposed. Decomposed Granitics The decomposed granitic materials at the site typically consist of silty fine- to very coarse-grained sand and weathered bedrock. Some jointing and frac- 5 - Luke-Dudek September 9,198s Project No. 100743-01 turing were observed in these materials, but this unit was generally observed to be massive. White veinlets of quartz rich material were observed locally in the test trenches. A leached, calcium carbonate-rich zone was observed in Trench No. 8. Based on our experience with this material type the expansion potential is considered to be low. Some fill soils are present in localized areas of the site. Fill soils were en- countered in our excavations at the chlorination building pad and in the ad- jacent canyon to the south to a maximum depth of approximately 3 feet. Density tests performed on samples from borings B-6 and B-7 indicate rela- tive compactions in the fill of 86 and 90 percent respectively. Based on our visual observations, it is anticipated that additional localized areas of fill are present along the paved roadways, particularly in the area of the chlorination building. The total depth of fill in these areas is not known. The fill soil ap- pears to have been generated from on-site decomposed granitics, and is con- sidered to have a low potential for expansion. Ground Water No seep, springs, or other indications of a shallow ground water table were observed at the site. Free water was not observed in our excavations or in the drainage courses. Employees of the Water District report that ground water is present at a relatively shallow depth in the the filled canyon south of the chlorination building, generally in the alignment of the inlet/outlet pipe for Squires Reservoir. Seismicity No active faults are know to occur on or adjacent to the site. The most significant seismic hazard at the site is ground shaking following an event on a distant active fault. Table 1 lists the major active regional faults, their distance from the site, anticipated peak bedrock 6 - Luke-Dudek September 9, 1988 Project No. 100743-01 acceleration, and repeatable high ground accelerations for the maximum probable earth- quake on each of these faults. The seismic event most likely to significantly affect the site would be the maximum proba- ble event on the Elsinore Fault, which could produce a peak bedrock acceleration of 0.19g and repeatable high ground acceleration of 0.12g. An event on the potentially active Rose Canyon fault zone could produce a higher peak bedrock acceleration, but this is considered less likely than an event on the active Elsinore Fault. Peak accelerations are not, however, generally used for design of structures. 7’he project seismic design should be completed in accordance with regulations of the governing jurisdictions and standard practices of the Structural Engineers Association of California. Due to the dense nature of the bedrock at the site, seismically induced liquefaction, dy- namic settlement or landsliding within the native materials is deemed unlikely. Due to the distance between the site and the closest know active fault, seismically induced ground rup- ture or cracking is also deemed unlikely. Rippability On May 17, 1988, our representatives performed eight seismic traverses at the site for the purpose of estimating rippability of the on-site materials. The results of the seismic tra- verses are presented in Appendix D. Analysis of the traverse results indicates that there are significant variations between surveys. These variations likely represent differential amounts of weathering across the site and, accordingly, it is anticipated that rippability may vary greatly across a relatively small area. Our seismic traverse results in conjunction with the results of our subsurface exploration program indicate that excavation for the proposed 7 foot deep pipeline, as shown on Plate 1, should be possible. In the area of the proposed tank, it is anticipated that non-rippable material may be encountered at variable depth ranging from approximately 15 to 25 feet below the existing ground surface, at elevations of approximately 480 to 492 feet M.S.L. Materials above these elevations are expected to be rippable or marginally rippable. 7 Luke-Dudek September 9, 1988 Project No. 100743-01 - CONCLUSIONS AND RECOMMENDATIONS Based on our field and laboratory test results, and the results of our analysis, it is our opinion that the proposed construction is feasible from a geotechnical standpoint provided the following recommendations are incorporated into the design, and sound construction practices are utilized. Recommendations for the site earthwork, concrete storage tank, the pump station, the pipeline alignment, the chlorination building expansion, the pipeline alignment, and the bulk storage tanks are provided below. The following recommendations are provided as general earthwork at the site. As neces- sary additional specific recommendations have been provided below for each area of the proposed development. Earthworks at the site should consist of site preparation, excava- tion into granitic materials, and placement of fill. Grading and earthwork should be per- formed in accordance with the following recommendations: 0 Site Preuaration Prior to earthwork, the site should be cleared of any existing debris, vegeta- tion, or other deleterious materials. Removed materials not suitable for structural backfill should be disposed of off-site or utilized in non-structural fill areas. During the site preparation, efforts should be made to excavate the bedrock within the building pad area to a relatively level surface. Com- pacted fill may then be placed directly on the bedrock. In general, excavation may be accomplished with heavy duty earthwork equipment. The results of our subsurface investigation conducted with a Caterpillar C-235 excavator indicated that appropriate excavation equipment in good working order should be able to excavate the bedrock materials to Luke-Dudek September 9,198s Project No. 100743-01 the proposed foundation level. However, blasting may be necessary if hard bedrock is encountered. Cut slopes should be constructed at an inclination no steeper than 21 (horizontal to vertical). If necessary, temporary shallow excavations with near vertical side slopes should generally be stable. To satisfy OSHA re- quirements, however, temporary excavations deeper than five feet should be braced or laid back at a ratio of at least 1:l if workers are to enter such exca- vations. 0 Fill Placement and Comuaction We anticipate that placement and compaction of fill soils will be necessary behind the retaining and tank walls proposed on the site and to create fill pads and fill slopes. The on-site soils are generally suitable for use as com- pacted fill. Fill soils should be free of organic material or debris. Any im- ported fill soils, if required, should be non-expansive and approved by the geotechnical consultant prior to being brought to the site. Fill soils should be moisture conditioned to near optimum moisture content, and compacted to a minimum of 90% relative compaction based on ASTM D1557-78. 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 in loose thickness. Fill slopes should be placed at an inclination no steeper than 21 (horizontal to vertical) and should be compacted to the slope face in accordance with the recommendations presented above. To achieve 90 percent relative com- paction on the slope face, the slope may be over built and cut back or may be backrolled at vertical intervals of 3 feet maximum. c - Luke-Dudek September 9,198s Project No. 100743-01 The following recommendations are provided for the ten million gallon concrete water storage tank: 0 Excavation Based on the results of our subsurface investigation, it appears that the east- ern portion of the tank is underlain by granitic rock at a depth of approxi- mately 15 feet. The granitic rock contact was evaluated to be at depths in ex- cess of 20 feet in the other borings drilled at the site. As the tank is to be founded at an elevation of approximately 485 feet, this would indicate that the eastern portion of the tank will be founded on granitic rock, while the re- maining portions of the tank will be founded on decomposed granitic rock. This situation would provide a differential foundation condition and likely lead to differential settlement of the tank structure in excess of tolerable limits. Accordingly, we recommend that the entire tank excavation be ex- tended an additional five feet in depth and replaced with suitable compacted fill soils. This will provide a relatively uniform foundation condition for a depth of five feet underlying the tank mat foundation. 0 TankDeb The mat foundation and sidewalls of the tank should be designed in accor- dance with the recommendations of the structural engineer. Based on dis- cussions with the structural engineer, total loads (tank plus water) of up to 2200 pounds per square foot are anticipated. The mat foundation placed on properly compacted fill soil, may be designed using an allowable bearing ca- pacity of 2200 pounds per square foot. The allowable bearing capacity may be increased by l/3 when considering loading of short duration such as wind or seismic forces. 10 Luke-Dudek September 9,198s Project No. 100743-01 Differential settlement of the mat foundation was estimated using test boring, laboratory, and seismic refraction data obtained from our investigation. Based on this data, assuming a rigid mat and a uniform bearing pressure of 2200 psf, we estimate elastic settlements as follows: 0 Mid point of southeast and northwest sides - negligible. 0 Midpoint of northeast and southwest sides - 3/4 inch. 0 Corners - l/4 inch. 0 Center - l/2 inch Most of the above settlement should occur during the initial application of loads. In order to reduce the potential for abrupt differential settlement, we suggest that the tank be filled in stages of between 5 and 10 feet of water, allowing at least 24 hours between each increment of filling. Large concrete mat foundations, such as those being utilized for the pro- posed tank, will experience some deflection due to the surcharge placed on the mat and the reaction of the soils directly underlying the mat. For use and design by the structural engineer, a modulus of subgrade reaction of 150 pounds per cubic foot may be utilized. This value is based on a unit square foot area and must be adjusted for large footings or mats. Adjusted values of the modulus of subgrade reaction, based on the actual tank area, may be ob- tained from Figure 2, for tanks of various widths (minimum dimension). 0 Lateral The mat foundation placed in properly compacted fill may be designed using a coefficient of friction of 0.35 (total frictional resistance equals coefficient of friction times the dead load). A design passive resistance value of 300 pounds per square foot per foot of depth (with a maximum of 3000 pounds - Luke-Dudek September 9, 1988 Project No. 100743-01 per square foot) may be used. The allowable lateral resistance may be taken as the sum of the frictional resistance and the passive resistance, provided the passive resistance does not exceed 2/3 of the total allowable resistance. Sidewalls for the concrete tank, backfilled with granular soils, may be de- signed using an equivalent fluid unit weight of 60 pounds per cubic foot for level or negative sloping backfill, with an inclination no steeper than 2:l (horizontal to vertical). These values assume non-expansive backfill and free draining conditions. 0 Underdrain To facilitate collection and removal of subsurface moisture and any tank seepage which may occur, we recommend the use of an underdrain. This un- derdrain should be placed under the entire tank and extend up the sidewalls in accordance with the Tank Underdrain Detail, Figure 3. The following recommendations are provided for the proposed station: Based on the results of our exploratory boring B-5, drilled with an eight inch rotary auger, it appears that drilling for the pump shafts using heavy drilling equipment in good working order may be accomplished to the proposed depths of ten feet below the existing grade. o Foundation Desien Foundations for the pump station should be designed in accordance with the recommendations of the structural engineer and the following geotechnical recommendations. These recommendations assume that the soils at finish 12 Luke-Dudek September 9, 1988 Project No. 100743-01 pad grade will have a low potential for expansion. This condition should be evaluated by the geotechnical consultant upon reaching finish grade. Footings Continuous concrete footings for the proposed pump station should be a minimum of 18 inches wide and embedded at least 24 inches be- low the lowest adjacent grade. These footings should be reinforced with at least two #4 reinforcing bars, top and bottom. At this depth, concrete footings placed in formational materials or properly com- pacted fill, may be designed using an allowable bearing capacity of 2500 pounds per square foot. To reduce the potential for significant differential settlement of the proposed structure, the footings should be founded either entirely in the fill or entirely in formational materi- als. If founded in fill, the fill thickness should be uniform under the footings. The allowable bearing capacity may be increased by l/3 when considering loads of short duration such as wind or seismic forces. Total and differential settlement of footings designed in ac- cordance with the above recommendations should be within normally tolerable limits, approximately 1 and l/2 inch, respectively. Floor Slab Floor slabs for the pump station should have a minimum thickness of four inches and be reinforced, at a minimum, with one #4 reinforcing bar on 18 inch centers, each way. We recommend the use of “chairs” to properly locate the reinforcement in the middle one-third of the slab thickness. If moisture sensitive equipment, or floor coverings, are to be installed, floor slabs should be underlain by a 6 mil v&queen moisture barrier, covered with at least two inches of clean, washed sand, and underlain by four inches of 3/S-inch gravel. The sand directly underlying the Luke-Dudek September 9, 1988 Project No. 100743-01 ,- slab should be moisture conditioned prior to concrete placement. The slab should have crack control joints with appropriate spacing as rec- ommended by the structural engineer. Lateral Resistance and Earth Pressures Foundations placed in properly compacted fill or formational materi- als may be designed using coefficient of friction of 0.35 (total fric- tional resistance equals coefficient of friction times the dead load). A design passive resistance of 300 pounds per square foot per foot of depth (with a maximum value of 3,000 pounds per square foot) may be used. The allowable lateral resistance may be taken as the sum of frictional resistance and the passive resistance, provided the passive resistance does not exceed 2/3 of the total allowable resistance. Sidewalls for the pump station backfilled, using granular soils, should be designed as restrained walls using an equivalent fluid unit weight of 60 pounds per cubic foot for level backfill and 85 pounds per cubic foot for sloping backfill at an inclination no steeper than 2:l (horizontal to vertical). These values assume non-expansive backfill and free draining conditions. Retaining walls should be provided with appropriate drainage as shown on Figure 4. e d t ons for Pioeline Alienment R mmnai eco The following recommendations are provided for the dual 42 inch diameter pipeline alignment: 0 Excavation An outcrop in Test Pit No. 6 of granitic rock was observed at a depth of ap- proximately 5-l/2 feet in a portion of the trench. This may indicate that in 14 Luke-Dudek September 9,1988 Project No. 100743-01 portions of the alignment, which were not excavated as part of our investiga- tion, hard granitic rock may be encountered at a depth shallower than 7 feet, and blasting may be required for removal. Groundwater was not encoun- tered during our subsurface exploration. However, if groundwater is en- countered during the construction the geotechnical engineer should be con- tacted to evaluate stability of the trench excavation and provide appropriate recommendations. Recommendations for Chlorination Building Exoansion The following recommendations are provided for the expansion of the existing chlorination building: 0 Site Preoaration and Fill Placement Prior to commencement of construction at the site, all asphaltic concrete and fill soil should be removed from within the proposed expansion building pad area plus 5 feet outside the perimeters of the foundations for the proposed structure. To reduce the potential for differential settlement of the proposed structure resulting from a non-uniform soil condition we recommend that the bottom of the foundation be placed directly on firm decomposed granitics. 0 Foundation Design Foundations for the subject expansion should be designed in accordance with the recommendations of the structural engineer, and the following geotech- nical recommendations. These recommendations assume that the soil at fin- ish grade will have a low potential for expansion. To reduce the potential for distress to the existing building we recommend that the proposed expansion be isolated unless special design recommendations are provided by the struc- tural engineer to attach the existing and proposed structures. Footing exca- vations should not be made within a horizontal distance of 3 feet of the ex- isting structure’s foundation. If the foundations for the expansion must be 15 - ,- c Luke-Dudek September 9,1988 Project No. 100743-01 placed adjacent to the existing structure, special care must be taken by the contractor not to undermine the existing foundation. Continuous footings for the proposed expansion should be a minimum of 18 inches wide and be imbedded at least 24 inches below the lowest adjacent grade. These footings should be reinforced with at least two #4 reinforcing bars top and bottom. At this depth the concrete foot- ings, placed on fii decomposed granitics may be designed using a al- lowable bearing capacity of 2500 pounds per square foot. The allow- able bearing capacity may be increased by l/3 when considering loading of short duration such as wind or seismic forces. Total and differential settlement of footings designed in accordance with the above recommendations should be within normally tolerable limits, approximately 1 and l/2 inch, respectively. .Floor Slabs Floor slabs for the expansion should have a minimum thickness of 4 inches and be reinforced, at a minimum, with one #4 rein- forcing bar on 18 inch centers, each way. We recommend the use of “chairs” to properly locate the reinforcement in the middle l/3 of the slab thickness. If moisture sensitive equipment or floor coverings are to be in- stalled, floor slabs should be underlain by a 6 mil visqueen mois- ture barrier covered with at least 2 inches of clean washed sand and underlain by 4 inches of 3/8-inch gravel. The sand directly underlying the slab should be moisture conditioned prior to con- crete placement. Slabs should have crack control joints with ap- propriate spacing as recommended by the structural engineer. 16 Luke-Dudek September 9,1988 Project No. 100743-01 The following recommendations provided for the two proposed bulk storage tanks: 0 Site Prenaration Prior to commencement of foundation construction, all asphaltic concrete and fill soil should be removed from within the proposed foundation area plus 2 feet outside the perimeter. To reduce the potential for a differential settlement of the proposed foundations resulting from a non-uniform soil condition, we recommend that the bottom of the foundations for the pro- posed bulk storage tanks be underlain by a minimum thickness of 2 feet of compacted fill soil or placed entirely on firm decomposed granitics. 0 Foundation Desian Foundations for the bulk storage tank should be designed in accordance with the recommendations of the structural engineer and the following geotechni- cal recommendations. These recommendations assume that the soils under- lying the foundations have a low potential for expansion. Continuous and isolated concrete footings for the proposed bulk storage tank should be a minimum of 18 inches wide and imbedded at least 24 inches be- low the lowest adjacent grade. These footings should be reinforced with at least two #4 reinforcing bars, top and bottom. At this depth concrete foot- ings, placed in properly compacted fill or on firm decomposed granitics, may be designed using an allowable bearing capacity of 2500 pounds per square foot. The allowable bearing capacity may be increased by l/3 when consid- ering loading of short duration such as wind or seismic forces. Total settle- ment of footings designed in accordance with the above recommendations should be within normally tolerable limits, approximately l/2 inch. 17 - - c Luke-Dudek September 9, 1988 Project No. 100743-01 Foundations placed in properly compacted fill may be designed using a coef- ficient friction of 0.35 (total frictional resistance equals coefficient of friction times the dead load). A designed passive resistance value of 300 pounds per square foot per foot of depth (with a maximum value of 3000 pounds per square foot) may be used. The allowable lateral resistance may be taken as the sum of frictional resistance and the passive resistance provided the pas- sive resistance does not exceed two thirds of total allowable resistance. + Concrete in direct contact with soil or water that contains a high concentration of soluble sulphates can be subject to a form of deterioration commonly known as sulphate attack. Deterioration from corrosion of metal pipes or reinforcement may result from contact with corrosive soils. It is our understanding that the evaluation of sulphate attack and corrosion potential at this site is not within the scope of our services. At the request of Luke-Dudek, we have provided samples of the soils encountered in our excavations to PSG Corrosion Engineering for evaluation and appropriate recommendations. Draina@ Positive site drainage should be established and controlled around each of the proposed structures at the subject site. Drainage control measures should include rain collection sys- tems such as gutters and downspouts for the proposed pump station, chlorination building expansion and concrete tank. Positive drainage should be established for surface runoff for each of the proposed structures., Positive drainage may be established by providing a ground surface gradient away from the structures of at least 2 percent for a distance of 5 feet outside the perimeter of the structures. Accumulated surface runoff should be di- rected off-site by providing a graded swale with a gradient of at least 1 percent to an ap- propriate surface collector and/or tightlined to a suitable outlet. Site runoff should not be permitted to run over the tops of slopes constructed at the site. A brow ditch should be constructed at the top of each of the fill or cut slopes to collect surface runoff and direct that runoff to a suitable outlet. 18 Luke-Dudek September 9, 1988 Project No. 100743-01 r r r Concrete Construction Concrete should be poured with a maximum slump of 4 inches under the observation and testing of a qualified materials testing laboratory. We recommend that a slump test be conducted for each concrete truck. Potential for slab shrinkage and associated cracking may be reduced by the addition of fiber mesh in the concrete and by careful control of wa- ter/cement ratios during concrete placement. Co n ti n The recommendations provided in this report are based on subsurface conditions disclosed by widely spaced excavations. The interpolated subsurface conditions should be observed by the geotechnical consultant, in the field, during construction. All geotechnical construc- tion should be observed by the geotechnical consultant. Geotechnical services outlined in this report have been performed in accordance with cur- rent practice and the standard of care exercise by geotechnical consultants performing sim- ilar tasks in this area. No other warranty, expressed or implied, is made regarding the con- clusions, recommendations and professional opinions presented in this report. Site con- ditions may vary from those observed in this report. Our conclusions and recommenda- tions are based on an analysis of the observed conditions. If actual conditions differ from those described in this report, our office should be notified and additional recommenda- tions, if required, can be provided upon request. 19 Luke-Dudek September 9,1988 Project No. 100743-01 c We appreciate this opportunity to be of service. Please do not hesitate to contact us if you have any questions regarding the contents of this report. Mark R. Cuthbert, RCE 40624 Manager of Engineering Thomas C. Gray, CEG 281 Chief Geologist MC/SWJ/REM/dh Distribution: (4) Addressee - 20 .I --. NY- /’ ,,,, ~~I:> :b~: ? __ .---..,i ,,,,,,,, ;,&.. _... -.-. -.. ,: & . ,i . $ 4 A’ L L : ; 7 s 0. .- ‘. 6 REFERENCE: 1986 Aerial Foto-Map Book. NORTH Scale in Feet SITE LOCATION MAP LUKE-DUDEKXOSTA REAL SAN DIEGO, CALIFORNIA PROJECT NO.1 DATE 10074361 1 S/88 FIGURE 1 - - - (qoul gqna Jed epunod) ~ou3v3~ 3avkmns do sninaow a3umrav (Y ii 2 iz 1 0 ; ? I c i : ; ; : J ;r 1 : : , a’ . . E I-, -0 - 0’ 5 - FILTER MATERIAL Filler material shall be Class 2 permeable material per State 01 California Standard Specificslions or approved alternate geofabric drain system. Class 2 grading as tollow6: SIEVE SIZE PERCENT PASSING 1’ 100 3 J4‘ go-100 3’8’ 40-100 No. 4 25-40 No. 8 18-33 No. 30 5-15 No. 50 o-7 ND. 200 o-3 PUMP STATION RETAtNlNG WALL \ f SOIL BACKFILL, COMPACTED TO Al LEAST 90 PERCENT REunvEcowwnord* b+& tna ; , O** * 0 0 0 OQ 0 o" o 0 I . 1 MIN. , 0 0 0 0 0 0 0, 0 o" 0 0 0 0 a.0 0 FLOOR SLAB - 7 6’ DIAMETER PERFORATED SCHEDULE i 40 PVC PtPE DR EDUVALENT tNSTALLED WALL FOOTtNG WALL FOOTtNG WITH PERFDRATfONS DOWN. MlNlMlJM WITH PERFDRATfONS DOWN. MlNlMlJM , PERCENTGRADIENTTOJUSTEEYON) , PERCENTGRADIENT TOJUSTEEYON) WALL AND THEN NON-PERFORATED PtPE WALL AND THEN NON-PERFORATED PtPE TO STREET OR SUTABLE OUTLET. TO STREET OR SUTABLE OUTLET. *BASED ON ASTM 01557-78 cuss 2 PERME*BLE ~nTmt MATERIAL, COMPACTED TO AT LEAST 90 PERCENT RELATIVE COMPACTION * IAMBS - NOT TO SCALE FIGURE 4 RETAINING WALLS DRAIN DETAIL . ,- - Luke-Dudek September 9,198s Project No. 100743-01 TABLE 1 SEISMICPARAMETERS Maximum Ap roximate ii* Probable istance Earthquake Peak **Repeatable From Fault Bedrock High Ground To Site M(aRi;$tner Acceleration Acceleration Fault (Miles) e el (Gravitv) (Gravitv) San Andreas 73 7.2 < 0.05 < 0.05 San Jacinto 4s 7.2 0.08 0.08 Coronado Banks 21 6.0 0.11 0.11 Elsinore 19 6.7 0.19 0.12 *Rose Canyon 6 6.0 0.35 0.23 \ This fault is considered “potentially active.” ** The repeatable high ground acceleration may be taken as 65% of the peak accelera- tion for sites within 20 miles of the epicenter (after PloesseI and Slossen, 1974). I I I I I 1 1 - I I I i I I I I i I I \ i APPEND IX A Luke-Dudek September 9,198s Project No. 100743-01 APPENDIX A References 1. Luke-Dudek, 1988, Pro voir, Costa rp osal for Facilities Up eal Municipal Water %. rade and Expansion for Squires Reser- rstrict, Project No. 87-109, February. 2. Luke-Dudek, 1988, Site Plans for Proposed development at various stages of prepara- tion, several dates. 3. Ploessel, M.R. and Slossen, J.E., 1974, Repeatable High Ground Accelerations From Earthquakes, Earthquake Engmeering Research Institute, Monograph Se- ries. ic Map of North-Central Costa1 Area of San Diego Recent Slope Failures and Predevelopment Aerial Photoeraphs -Date ___Flight --Jg&&$ USDA ’ 4-11-53 1:20,000 AXN-SM 22 and 23 i i I 1 I 1 I I I I I I I 1 1 i 1 I i APPENDIX B - MAJOR DIVISIONS Sm TYPICAL NAMES GW Well graded gravels or gravel-sand mlxtures. little er no fines GRAVELS GP Poorly graded gravels or gravel-sand mixtures, little or no fines (More than ,/2 of I:=-i; coarte fraction GM Silty grsvels. gravel-sand-silt mixtures 525 UJ, - ~No. 4 sieve size) 0”: y Y .z GC Clayey gravels. gravel-sand-clay mixtures ;i” c co 0::: SW Well graded sands or gravelly lands, little or no fines Lied sa= SANDS $“A SP Poorly graded sends or gravelly sands, little 01 ne finer (More than l/2 of coarse fraction SM Silty sands, sand-silt mixtures < No. 4 sieve sire) SC Clayey sands, sand-clay mixture6 ML Iwrgsnic silts and very fine sends, rock flour, silty or clayey fine sand SILTS a CLAYS ot clayey eilts with slight plasticity cjy CL tnorganic clays of low to medium plasticity, gravelly clays, sandy clays E- 2 Liquid Limit ~50 swy clays, lean cleys p 9-2 OL Oiganic silts and organic silty clays of low plasticity z sg %SN MH Inorganic silts, micace,our QI diatomaceous fine sandy or silty solle, IllEd SILTS & CLAYS elastic silts z Eel/ Liquid Limit > 50 CH kiorgsnlc cleys of high plasticity, fat clays OH Organic clayt of medium to high pfaotlclty, organic silty Maye, o(9anic silts HIGHLY ORGANIC SOILS Pt Pbat and other hlghty organic soils CLASSIFICATION CHART (Unified Soir Classification System) ClASStFlCAllON 6oulDERS RANGE OF GRAIN StaS U.S. Standard Grain Sire Sieve Sire in Mlllirneters Above 12’ I Above 305 I Medium COXSO Fine I No. No. No. 40 10 4 to to to No. NO. No. 200 10 40 I 0.420 2.00 4.76 to to to 0.420 0.074 2.00 I I SILT a CLAY 1 Below No, 200 Below 0.074 GRAIN SIZE CHART 0 0 10 20 30 40 50 60 70 60 LlOUlD LIMIT tu), % PLASTICITY CHART - -/j@kayo~~~ore~ U.S.C.S. METHOD OF SOIL CLASSIFICATION 190) DATE DRILLED GROUND ELEVATION METHOD OF DRILLING DRIVE WEIGHT SAMPLED BY BORING NO. SHEET __ OF - DROP LOGGED BY DESCRIPTION Undisturbed drive sample Relative compaction Bulk sample seepage Zround water table Standard penetration test jolid line denotes formation change -- ---- lashed line denotes lithologic gradational change, BORING LOG Explanation of Boring Log PROJECT NO. DATE I FIGURE r (d3d) AllSN3a ALla FIGURE ,- r 7 r ,- f- ,- GROUND ELEVATION 487'- (MSL) SHEET-.!- OF 2 METHOD OF DRILLING DRIVE WEIGHT 140 lbs. DROP 30” SAMPLED BY Red-brown, dry, dense, silty, fine to, coarse-grained s+ND!. @ 2.0': Light brown, dry to damp, dense, fine to very coarse- grained, angular, silty SAND. Light to medium brown, damp, slightly cemented, fine to very coarse-grained, silty SAND; angular. @ 6.0': Color change to medium yellow-brown. 1.0': Medium yellow-brown, damp, medium well cemented;. me to very coarse-grained, silty SAND; angular. Consistancy change to more well cemented; color change to a light to medium yellow-brown. Total Depth 20.0'. No Ground Water Encountered. Backfilled 7/26/88. BORING LOG Luke Dudek/Costa Real San Diego, California PROJECT NO. DATE 100743-01 7/26 FIGURE B-1 GROUND ELEVATION SHEET 1 OF 2 METHOD OF DRILLING 8” Diameter Rotary Auger 140 lbs. 30” DRIVE WEIGHT DROP SAMPLED BY Medium red-brown, dry, dense, very silty fine to coarse SAND. @ 3.0': Medium brown, damp, dense, fine to coarse, silty @ 7.0': Hard drilling. @ 10.0': Color change to medium yellow-brown. cola change to medium brown. Total Depth 20.0'. NC, Ground Water Encountered. Backfilled 7/26/88. BORING LOG L"ke Dudek/Costa Real San Dieqo, California PROJECT NO. DATE 100743-01 9/88 FIGURE E-2 tl 5 DATE DRILLED ?/26/88 BORING NO. B-3 E! ; :, 2 0 = I GROUND ELEVATION 506’+ (MSL) SHEET 1 OF 2 z 3 0 Z” Y- E z x iz (j EU METHOD OF DRILLING 8” Diameter Rotary Auger F 2 g u, B 5: :5 DRIVE WEIGHT 140 lbs. El 9 DROP 30” 0 a? m6 i % iz 0 SAMPLED BY LPR/MAS LOGGED BY LPR/MAS 0 DESCRIPTION D RESIDUAL SOIL/DECOMPOSED GRANITICS: SM Medium red-brown, dry, fine to coarse-grained, clayey, silty SAND. DECOMPOSED GRANITICS: @ 2.5': Medium yellow-brown, damp, fine to coarse-grained, silty SAND; micaceous. 5 @ 5.0': Hard drilling. @ 5.5’: Small rock fragments. D Drilling becomes slightly easier. @ 11.0': "Moderately hard" drilling. I5 GP.ANITIC,ROCK: @ 14.5': contact with underlying granitic rock; rotary wash drilling begun with 3-3/4" tri-cone drill bit at 600 Psi. Drilling rate approximately 1" per minute. 0 BORING LOG Luke Dudek/Costa Real San Diego, California PROJECT NO. DATE 100743-01 9/88 FIGURE B-3 In DATE DRILLED 7/26/88 2 3 BORING NO. B-3 % $ P 5 3 gj GROUND ELEVATION 506lc (MSL) SHEET 2 OF 2 it?;! 1 1 g METHOD OF DRILLING 8" Diameter Rotary Auger -- DRIVE WEIGHT 140 lbs. DROP 30” z;>: z m; 9 0 i ” SAMPLED BY LPR/MAS LOGGED BY ~%!!!As DESCRIPTION ----E GRANITIC ROCK: (CONTINUED) 0 Total Depth 30.0'. Hole terminated due to loss of water circulation. Backfilled 7/26/88. 5--- d BORING LOG Luke Dudek/Costa Real c PROJECT NO. DATE 100743-01 9/88 FIGURE S-4 SHEET 1 OF 2 METHODOFDR~LL)NG 8" Diameter Rotary Auger DRIVE WEIGHT 140 lbs. DROP 30” SAMPLED BY LPR/MAS LOGGEDSY _ LPR/MAS silty fine to coarse SAND. @ 2.0': Medium brown, damp, very dense, silty fine to very coarse SAND. SM @ 5.0': Medium yellow-brown, damp, very dense, silty fine to very cc~arse SAND; micaceous. @ 7.5': Rock fragments. X-SM @ 10.0': Medium yellow-brown, damp, very dense, fine to coarse-grained, silty, clayey SAND. I- I5--- @ 15.0':'"Substantially harder drilling" - per driller. @ 19.0': Drilling becomes harder according to driller, l-2" thick zones of softer material. 0 BORING LOG Luke Dudek/Costa Real San Diego, California PROJECT NO. DATE 100743-01 9/88 FIGURE E-5 DATE DRILLED GROUND ELEVATION Lo2 I’ (MSL) METHOD OF DRILLING 8” Diameter Rotary Auger -- DRIVE WEIGHT 140 lbs. SAMPLED BY LPR/MAS LOGGEDBY dpR/ms clayey SAND. Total Depth 22.5'. (Auger Refusal) NO Ground Water. Backfilled 7/26/88. BORING LOG Luke Dudek/Costa Real c PROJECT NO. DATE 100743-01 9/88 1 FIGURE B-6 u1 !I c DATE DRILLED 7/26/88 BORING NO. B-5 : k 2 hi S :: GROUND ELEVATION 355'+ (MSL) SHEET1 OF -!- sou& g $4 5-F z E” METHOD OF DRILLING 8” Diameter Rotary Auger z 3g 2 2 v) $5 DRIVE WEIGHT 140 lbs. Beefy 2 > -j DROP 30” 0 == m ‘DE 0 SAMPLED BY LPR/MAS LOGGED BY LPR/MAS B DESCRIPTION D DECOMPOSED GPANITICS: SM-SW Light brown, dry, dense, fine to coarse-grained, slightly silty SAND/well-graded SAND; moderately hard drilling. L- D Total Depth 10.0'. NO Ground Water. Backfilled 7/26/88. 5--- D BORING LOG Luke Dudek/Costa Real San Diego, California PROJECT NO. DATE 100743-01 9/88 FIGURE S-7 DATE DRILLED GROUND ELEVATION 352’-+ (MSL) SHEET - ’ OF1 METHOD OF DRILLING 0” Diameter Rotary Auger DRIVE WEIGHT 140 lbs. DROP 30” SAMPLED BY LPR/MAS LOGGED BY LPR/NAS fine to coarse-grained, silty, clayey SAND. @ 2.5': Medium orange-brown to red-brown, damp, very dense, L fine to coarse-grained, silty SAND. 5--- 0 Total Depth 10.0'. NO Ground Water. Backfilled 7/26/88. 5--- , BORING LOG Luke Dudek/Costa Real San Diego, California PROJECT NO. DATE 100743-01 9/88 FIGURE S-8 .,>i~, t: 5 DATE DRILLED 7/26/88 2 BORING NO. B-7 El T 6 2 P z 0 F GROUND ELEVATION 352’f (ML.1 *:vj SHEET1 OF 1 E-- k c 26 * z METHOD OF DRILLING 8” Diameter Rotarv Auser F gu, g 2 Yh $=5f 0 $5 DRIVE WEIGHT 140 lbs. DROP 30” o=zi s 9 m; z 0 SAMPLED BY LPR/MAS LOGGED BY 0 LPR/MAS DESCRIPTION 0 ASPHALTIC CONCRETE: Approximately 2" thick, no base materia FILL: 7.3 117.3 SM Medium brown, damp, medium dense, slightly clayey, silty, fine to coarse-grained SAND. DECOMPOSED GRANITICS: SM Medium brown, damp, dense, fine to coarse-grained, silty SAND. 5 --- o-- Total Depth 10.0'. NO Ground Water. Backfilled 7/26/88. 5--- 0 BORING LOG Luke Dudek/Costa Real San Diego, California PROJECT NO. DATE 100743-01 9/88 FIGURE B-9 J ~ ‘s’3’s’ll N011V31dlSSV13 Wd) AiISN3Q ma (%) 3mlsIow I U33j) Hld3(1 I I I I I I I I I I I -- . . . . . . . . . -.., J i...... I I I I I I I I -++74-- d N -,-,.., ,..,... __ ..,..,... .-..,. ___..~ . . : ~ t I FIGURE E-’ FIGURE s-1 1 Wd) AllSN3(1 ua (133d) Hld3a I I I I FIGURE S-1: FIGURE S-1: ‘SSSTI N011V31d1SSV13 (d3d) AlISN30 ma (1333) Hld3a I ! I I I I I I I I I I I I I 0., rl 4~‘~ m Q m rD P I I I I +..-y ..- fiw+~~ j- f .._... ~.~ -j I~....,.,. .,.., i.~ ___.-... ~~~~f .,_-,.. ~.~~ . ..f .___... j 'S3's'fl N011V31dlSSV13 (d3d) AllSN30 AtlO (1333) Hld30 I I I I I I I I I I I I I I I I I I I I I 0 rl N m 9 m ID P Ql (dad) AlISN30 ALIG (96) 3tlnistow (1333) Hld3Q I I I I FIGURE B- FIGURE B- 'S'XSn N011V'31dlSSV13 Wd) AllSN3G AHG (a) 3mlsboyY ..ldl*b (1333) Hld30 I I I I I I I I I I I I I I I .^ .,,............ - __I,_..... - . ~... 1 / I ..,,..... -,,,~ v ^.... i .-^.” “- ~- _........, .-^.” “- ~- _........, I I I I I I FIGURE S-1 FIGURE S-1 FIGURE 8-l FIGURE B-’ (d3d) AllSN30 AUG (a) 3mmow FIGURE E-20 b r; ci; 5” aa tL 24 5.5 Ftzz $“U 000 hZZ r r FIGURE E-2 : I I 1 I I I I I 1 I I I I I I I I I I APPENDIX C 135 ,A-.++ I :. , 3a p-J ‘;:‘f; ~ ,25 ‘1. ._I .._. _ . j .._. -, -.& : .,...... +., i -... .* ..-_ , 2a y+- -“+“‘- K . . _..__. + -i-._.; 3 P s- t I? iFI ; i ~ : i i i : ~ : ’ Jo .:j. :, i&q+& I 9 i -+e .; 100 ;;;:I;: ;(~. iI/; g! 7-y -7-r s5 IjFi,j. : / ;, Zero Air Voids Curves 5 30 36 40 MoisTuRE CONTENT (PERCENT 0~ DRY WEIGHT) I SAMPLE DEPTH LOCATION IN FEET SOIL DESCRIPTION B-6 0.5-3.5’ Brown-orange silty SAND (SM) I TEST RESULTS MAY BE SUBJECT TO “ARIRTION. PERFORMED IN GENERAL ACCORDANCE WITH ASTM b1667-76 I MAXIMUM DENSITY TEST RESULTS Luke-Dudek/Costa Real San Diego, California PROJECT NO. 1 DATE I FIGURE C-l 100743-01 9/m GRlYEL I SAND I FINES CO,r*e Fh, coars. M.di”nl I Fl”. Sll, I CIW “S. STANDARD SEVE NUMBERS ““OROMETER 0 I II I I II I Ill I I I II I I I I l[llll! I I I I !IlIII! I l I rrllll; : ! I J 10 10 5 1 OS a, 0.m 0.0, o&Q, MO, 090* GRNN SEE IN MIUMETERS 7 SymLd “0,. Number D.Fm h.1, Liquid udt PI.S,k Limit Ph*tlclty Index. 5011 TIP. B-2 2.0-2.1’ SM I GRADATION TEST RESULTS I I I Luke-Dudek/Costa Real San Diego, California PROJECT NO. 1 DATE FIGURE C-2 100743-01 I 9/ss I - ,- - ,- SYMBOL LOCATION DEPTH % PASSING 200 l TP-3 5.0-7.0’ 10.0 60 60 40 30 20 10 0 ‘I 0 10 20 30 40 50 60 70 60 PL (%I 36 PI (%) 2 SM * Entire Sample LIOUID LIMIT ILL), % miNGEtERAL -ANCE WlTH A6TM D 431S-S4. ATTERSERG LIMITS TEST RESULTS Luke-Dudek/Costa Real San Diego, California PROJECT NO. 1 100743-01 DATE FIGURE C-3 9/ss I 1 I 1 I I I I I I I I i 1 I I ! 1 1 I ~J APPENDIX D - - - - r 2 g “, 2 s :: : : : E 0 c (sPuo-wll!w) 3Wll ,- - - - - - -~ - -. - r 0 54 m “E”,SS:: :: c o 0 ,o (sPuo~-llllw) 3yYll a c ( -. r 8 0 0) 0 OD E 0 u) :: : : z z 0 (sPuo~~sllllbu) 3r4ll r- - - - - .- - - 0 z a “, 0 u) :: : s: : o .- (sPuo~~wlrS) !lWII I : : i r - - .- - - - z o 0 : El s :: : : :: 0 - 0 (sPuo=sllllw) 3Wll r- - -. - - - - 1 f (SPuooewlllw) 3Wll P; n i $ 1 0 : ? i c ; I- c : c c 7 - - - - - I r g 0 aI 0 m E 2 2 z s: s 0 0 (sPuo~wlllw) 3Wll