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HomeMy WebLinkAbout3889A; Proposed Twin "D" Recycl Water Pump Station; Soils Report; 2002-09-27. RECEfVEB OCT 9 2 2002 KRIEGER & STEWART Preliminary Geotechnical Investigation Proposed Twin "D" Recycled Water Pump Station Black Rail Road, Carlsbad September 27,2002 Prepared For: KRIEGER & STEWART, INC. Attention: Mr. Philip Strom 3602 University Avenue Riverside, California 92501-3331 Prepared By: VINJE & MIDDLETON ENGINEERING, INC. 2450 Vineyard Avenue, Suite 102 Escondido, California 92029 JO b #02-204-P r ._ m.JE 63 MlDDLETON ENGINEERING, INC. - 2450 Vineyard Avenue, #lo2 Escondido, California 92029- 1229 -~ Phone (760) 743-1214 Job #02-204-P Fax (760) 739-0343 September 27,2002 Krieger & Stewart, Inc. Attention: Mr. Philip Strom 3602 University Avenue Riverside, California 92501-3331 PRELIMINARY GEOTECHNICAL INVESTIGATION, PROPOSED TWIN “D” RECYCLED WATER PUMP STATION, BLACK RAIL ROAD, CARLSBAD Pursuant to your request, Vinje & Middleton Engineering, Inc., has completed the Preliminary Geotechnical Investigation Report for the proposed Twin “D Recycled Water Pump Station at the above-referenced project site. The following report summarizes the results of our field investigation, laboratory analyzes and conclusions, and provides geotechnical recommendations for the proposed construction as understood. In our opinion, the study site is suitable for the support of the planned pump station from a geotechnical engineering standpoint provided the recommendations presented in this report are incorporated into the final plans and implemented during the construction phase of the project. Thank you for choosing Vinje & Middleton Engineering, Inc. If you have any questions concerning this report, please do not hesitate to call the undersigned. Reference to our Job #02-204-P will help to expedite our response to any inquiries. We appreciate this opportunity to be of service to you. VINJE & MIDDLETON ENGINEERING, INC. Dennis Middleton CEG #980 DMIjt . TABLE OF CONTENTS PAGE NO . 1 . INTRODUCTION .................................................. 1 II . SITE DESCRIPTION I PROPOSED DEVELOPMENT ..................... 1 111 . SITE INVESTIGATION ............................................. 1 IV . GEOTECHNICAL CONDITIONS ....................................... 2 A . Earth Materials ................................................. 2 B . Groundwater .................................................. 2 C . Faults/Seismicity ............................................. 2 D . Geologic Hazards .............................................. 5 E . Laboratory Testing I Results ...................................... 5 V . CONCLUSIONS .................................................. 7 VI . RECOMMENDATIONS ............................................. 8 A . Limited Ground Preparations and Remedial Grading ................. 8 B . Foundations and Slab-on-Grades ................................ 11 C . Exterior Concrete Flatworks ..................................... 12 D . Soil Design Parameters ........................................ 13 E . General Recommendations ..................................... 14 VI1 . LIMITATIONS ................................................... 15 TABLE NO . Faultzone .......................................................... 1 Site Specific Seismic Parameters ....................................... 2 SoilType ........................................................... 3 Maximum Dry Density and Optimum Moisture Content ..................... 4 Moisture-Density Tests (Undisturbed Chunk Samples) ..................... 5 ExpansionlndexTest ................................................. 6 DirectShearTest .................................................... 7 . TABLE OF CONTENTS (continued) PLATE NO . RegionallndexMap .................................................. 1 Site Plan ........................................................... 2 TestPitLog(with key) ................................................ 3 Fault-EpicenterMap ................................................. 4 Isolation Joints and Re-entrant Corner Reinforcement ..................... 5 Retaining Wall Drain Detail ............................................ 6 , -- PRELIMINARY GEOTECHNICAL INVESTIGATION PROPOSED TWIN “D” RECYCLED WATER PUMP STATION BLACK RAIL ROAD, CARLSBAD 1. INTRODUCTION The site investigated for this work includes a portion of the Twin “D water tank facility located southeast of the intersection of Poinsettia Lane and Black Rail Road within the City of Carlsbad. The site location is depicted on a Regional Index Map enclosed with this report as Plate 1. We understand that a pump station, consisting of a masonry building enclosure with associated improvements, is planned near the existing chlorine building in the northwestern area of the Twin “D tank site. Consequently, this investigation was initiated to determine geotechnical conditions at the proposed pump station and their influence upon the planned construction. Test pit digging and soil sampling and testing were among the activities conducted in connection with this investigation which has resulted in construction and development recommendations provided herein. Our scope of services were limited to the area planned for the new construction as delineated in this report. Other portions of the project site and existing structures not investigated were beyond the scope of this report. II. The project area is located in the northeastern section of the existing Twin “D” Tank Site. The study construction site consist of a nearly level surface which presently supports asphaltic paving and landscaping. A portion of a Site Plan, prepared by Krieger & Stewart, Inc., which depicts the existing site conditions and the proposed pump station has been reproduced and included with this report as Plate 2. As shown, an approximate 600 square foot masonry pump station building, which will house 4 vertical turbine pumping units, is planned for the study area. Among the associated improvements are new piping units connecting the pump station to nearby reservoirs. 111. SITE INVESTIGATION Geotechnical conditions at the study location were chiefly determined by the excavation of one hand-dug test pit. Manual hand-excavation methods were utilized in view of the existing utility lines known to cross the facility. The selection of the test pit location was also limited by existing site structures. Subsurface exposures within the Test Pit excavation were logged by our project geologist who also retained representative soillbedrock samples for subsequent laboratory testing. The Test Pit location is shown on Plate 2. A detailed log of the Test Pit is enclosed with this report as Plate 3. SITE DESCRIPTION I PROPOSED DEVELOPMENT VINJE Sr MlDDLETONENGINEERINQ, INC. 2450 Vineyard &ewe, #102, Ewmdido, oIlij%mia 92029.1229 Phau (760) 743-1214 Fox 1’160) 7394343 FEOTECHNICAL INVUITIGATIONS GR-ING SUPERVISION PERC TESTING ENVlRONMEKTAL IWW71GAT10~ PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 2 BLACK RAIL ROAD, CARLSBAD SEPTEMBER 27,2002 IV. GEOTECHNICAL CONDITIONS The project area is largely natural terrain underlain by sedimentary formational units that are widely exposed in local areas. Significant slopes do not occur in the proximity to the project construction site. A. Earth Materials The project site is underlain by a section of Pleistocene age Terrace Deposit soils which characterize much of the coastal surface terrain in surrounding areas. Site Terrace Deposits typically consist of fine to medium grained sandstone found in a dense and moderately cemented to cemented condition overall. A thin layer of topsoil mantles project Terrace Deposits. Topsoils are silty fine sands typically found in a dry and loose condition. Site topsoils are characterized by numerous roots and rootlets. Project earth materials are sandy deposits with very low expansion potential. Details of site earth materials underlying the area are given on Plate 3. B. Groundwater Groundwater conditions were not encountered in our exploratory test excavations to the depths explored and are not expected to impact the proposed construction. However, like all graded building sites, the proper control of surface drainage is an important factor in the continued stability of the property. Irrigation and meteoric water should not be allowed to pond on finish surfaces, and over-watering of site vegetation should be avoided. C. Faults I Seismicitv Faults or significant shear zones are not indicated on or near proximity to the project site. As with most areas of California, the San Diego region lies within a seismically active zone; however, coastal areas of the county are characterized by low levels of seismic activity relative to inland areas to the east. During a 40-year period (1934-1974), 37 earthquakes were recorded in San Diego coastal areas by the California Institute of Technology. None of the recorded events exceeded a Richter magnitude of 3.7, nor did any of the earthquakes generate more than VINJE @MIDDLfiTONENGIh'EERIN(j, WC. 2450 Vi-davmUe, #IO& Ere&, California 92029-1229 Ph (7601 743.1214 Fer (760) 739.0343 ENVIRONMENTAL INYEF716ATlO~ GEOTECHNICAL INVESTIGATIONS GRADIN0 SUPERVISION PERC TESTING , -- Newport-lnglewood fault 8.8 miles 0.1339 - Coronado Bank fault 21 .O miles 0.1419 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 3 BLACK RAIL ROAD, CARLSBAD SEPTEMBER 27,2002 I Elsinore fault 24.2 miles 0.108g modest ground shaking or significant damages. Most of the recorded events occurred along various offshore faults which characteristically generate modest earthquakes. Historically, the most significant earthquake events which affect local areas originate along well known, distant fault zones to the east and the Coronado Bank Fault to the west. Based upon available seismic data, compiled from California Earthquake Catalogs, the most significant historical event in the area of the study site occurred in 1800 at an estimated distance of 7.8 miles from the project area. This event, which is thought to have occurred along an off-shore fault, reached an estimated magnitude of 6.5 with estimated bedrock acceleration values of 0.1 16g at the project site. The following list represents the most significant faults which commonly impact the region. Estimated ground acceleration data compiled from Digitized California Faults (Computer Program EQFAULT VERSION 3.00 updated) typically associated with the fault is also tabulated. TABLE 1 I\ Rose Canyon fault I 0.180a II ~ ~~ VINJE B MIDDLETON ENGINEERING, INC. 2450 Vineyard Auewr, Y102, Ereandido. Cnlifomio 92029-1229 * Phon. (760) 743.1214 Fa 1760) 739.0343 GEOTECHNICAL INVESTlGATlONS GR*DING SUPERVISION PERC TESTING EWJIRONMENTAL rNvFwlOATlnNP PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 4 BLACK RAIL ROAD, CARLSBAD SEPTEMBER 27,2002 A series of notable events shook County areas with a (maximum) magnitude 7.4 shock in the early morning of June 28, 1992. These quakes originated along related segments of the San Andreas Fault approximately 90 miles to the north. Locally high levels of ground shaking over an extended period of time resulted; however, significant damages to local structures were not reported. The increase in earthquake frequency in the region remains a subject of speculation among geologists; however, based upon empirical information and the recorded seismic history of County areas, the 1986 and 1992 events are thought to represent the highest levels of ground shaking which can be expected at the study site as a result of seismic activity. In recent years, the Rose Canyon Fault has received added attention from geologists. The fault is a significant structural feature in metropolitan San Diego which includes a series of parallel breaks trending southward from La Jolla Cove through San Diego Bay toward the Mexican border. Test trenching along the fault in Rose Canyon indicated that at that location the fault was last active 6,000 to 9,000 years ago. More recent work suggests that segments of the fault are younger having been last active 1000 - 2000 years ago. Consequently, the fault has been classified as active and included within an Alquist-Priolo Special Studies Zone established by the State of California. Fault zones tabulated in the preceding table are considered most likely to impact the region of the study site during the lifetime of the project. The faults are periodically active and capable of generating moderate to locally high levels of ground shaking at the site. Ground separation as a result of seismic activity is not expected at the property. For design purposes, site specific seismic parameters were determined as part of this investigation in accordance with the Uniform Building Code. The following parameters are consistent with the indicated project seismic environment and may be utilized for project design work: TABLE 2 According to Chapter 16, Division IV of the 1997 Uniform Building Code. VINJE 8 MIDDLETON ENFINEERINF, INC. 245OVinqulrdhmue, XIOZ, Escadido, Ollifmn*92029.1229 Phonr (760) 743-1214 Fa (760J 739.0343 - GEOTECHNICAL INVESTIGATIONS GRMING SUPERVISION PERC TESTING ENV1RO”TAI INVE.WIGATIONS . , 1 red-brown silty fine sand (topsoil) - 2 red-brown fine to medium sandstone (Terrace Deposit) ! ;. , --- .. ! PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 5 ~- BLACK RAIL ROAD, CARLSBAD SEPTEMBER 27,2002 D. Geo logic Hazards Geologic hazards are not presently indicated at the project site. Minor exposed slopes do not indicate gross geologic instability. The most significant geologic hazards at the property will be those associated with ground shaking in the event of a major seismic event. Liquefaction or related ground rupture failures are not anticipated. E. Laboratory Testina I Results Earth deposits encountered in our exploratory lest excavations were closely examined and sampled for laboratory testing. Based upon our test trench data and field exposures, site soils have been grouped into the following soil types: TABLE 3 I TP-1 @ X I 1 I 133.2 I 10.2 2. Moisture-Density Tests Wndisturbed Chunk SamD les): In-place dry density and moisture content of representative soil deposits beneath the site were determined from relatively undisturbed chunk samples using the water displacement test method. The test results are presented in Table 5 and tabulated on the enclosed Test Pit Log. VINJE B MIDDLETON ENGINEERING, INC. 2450 W-rd Aunuo. 1102, Escmdido, Cklifmni. 92029.1229 Ph (760) 743,1214 Fa 1760) 739-0343 ENVIRONMEhTAI Im-m.TmM PERC TESTING GEOTECHNICAL INVESTIGATIONS GRADING SUPERVISION PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 6 BLACK RAIL ROAD, CARLSBAD SEPTEMBER 27,2002 TABLE 5 - 11 TP-1 @ 1% 1 2 I 3.0 1 123.9 I - I TP-1 @ 2%' 2 3.7 110.2 - - TP-1 @ 3' 2 4.8 117.9 Designated as relative compaction for structural fills. 3. Expans ion Ind ex Test: One expansion index test was performed on a representative sample of Soil Type 1 in accordance with the Uniform Building Code Standard 18-2. The test result is presented in Table 6. TABLE 6 TP-1 @ % 1 7.2 50.3 12.4 0 very low (w) = moisture content in percent. 4. Direct Shear Test: One direct shear test was performed on a representative sample of Soil Type 2. The prepared specimen was soaked overnight, loaded with normal loads of 1, 2, and 4 kips per square foot respectively, and sheared to failure in an undrained condition. The test result is presented in Table 7. TABLE 7 .- VlNJE 8 MIDDLETON ENGINEERING, INC. 2450 W-d Aumur, #102, Escondida, California 92029-1229 Ph (760) 743,1214 Fa (760) 739.0343 GRADING SUPERVISION PERC TESTING ENVIRONMENTAL INVESTIGATIONS GEOTECHNICAL INVESTIGATIONS PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 7 BLACK RAIL ROAD, CARLSBAD SEPTEMBER 27,2002 V. CONCLUSIONS Based upon the foregoing investigation, development of the project construction site for a pump station is feasible from a geotechnical viewpoint. The properly is underlain by dense, stable terrace deposits at very shallow depths which will provide adequate support for the planned pump station. Geologic instability or adverse geotechnical conditions are not indicated at the project construction site. The following factors are unique to the study construction site and will most impact its development from a geotechnical viewpoint: * Exposed surface areas of the project site are mantled by a thin cover of natural topsoil. These are shallow, sandy deposits which occur in a loose condition overall. * Removal and recompaction of existing topsoils and upper weathered terrace deposits will be necessary in order to construct stable ground suitable for the support of the proposed structures and improvements. Generated soils will predominantly be granular, non-expansive to very low expansive sands which work well in compacted fills. Unusual grading problems, including hard excavations or trenching difficulties, are not expected. Final bearing and subgrade soils are anticipated to consist of silty sands (SM) with very low expansion potential (El less than 21), according to the Uniform Building Code classification. Actual classification and expansion characteristics of the finish grade soil mix can only be provided in the final as-graded compaction report based upon proper testing of foundation bearing soils when rough finish grades are achieved. Natural groundwater was not encountered and is not expected to impact project grading or the long term stability of the developed construction site. Adequate site surface drainage control is a critical factor in the future stability of the developed property as planned. Drainage facilities should be designed and installed for proper control and disposal of surface runoff. Liquefaction and seismically induced settlements will not be a factor in the development of the proposed construction site. * * * * * VINJE 6) MIDDLETON ENGNEERING, INC. 2450 Vineyardhue, M02, Escadida, California 92029-1229 * Phav (760) 743,1214 Fa (760J 739.0343 GEOTECHNICAL INVESTlGATlONS GRADING SUPERVISION PERC TESTING ENVIROWNTAL lNVESTIGATIONS PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 8 BLACK RAIL ROAD, CARLSBAD SEPTEMBER 27,2002 * Post construction settlements will not be a factor in the development of the project construction site, provided our remedial grading and foundation recommendations are implemented during the construction phase of the project. * Soil collapse will not be a factor in development of the study site, provided our recommendations for site development are followed: VI. RECOMMENDATIONS Recommendations given below are consistent with the indicated geotechnical conditions at the study construction site and should be incorporated into final plans and implemented during the construction phase of the project: A. Limited G round Preparations a nd Rerned ial Grading I. Existing Underground Utilities: All existing underground utilities and facilities to remain at or nearby the project construction site should be identified and marked prior to the initiation of the actual ground preparations and remedial grading works. Specific geotechnical engineering recommendations should be given at the time of earthwork operations based on the actual exposures in the event of a conflict. 2. Clearing and Grubbing: The existing asphalt and landscaping should be neatly saw cut and/or removed from the proposed pump station building and improvement areas plus a minimum of 3 feet, where possible, and as approved in the field. Excess debris and other unsuitable materials should be removed from within the specified areas. The prepared ground should be inspected and approved in the field by the project geotechnical engineer or his representative. 3. Overexcavations/Removals: The project construction site is covered with a shallow mantle of loose topsoils on the order of I-foot thick. Existing topsoils and upper weathered Terrace Deposits beneath the planned structures and improvement areas plus 3 feet , where possible, and as approved in the field, should be over-excavated and recompacted. For this purpose, limited removals and ground preparations will be required. Removal depths will be on the order of I-foot with the bottom of over-excavations additionally ripped and recompacted in-place to a minimum depth of 6 inches. Deeper removals and soil densification beneath the planned structures and improvements may also be necessary based on actual field exposures and should be anticipated as directed in the field by the project geotechnical engineer. VINJE B MIDDLETON ENGINEERING, INC. 2450 Vineyard Awn-, Vl02, Esradido, WiM 92029.1229 Ph (760) 743.1214 Fa (760) 739.0343 GEOTECHNICAL INYESTIGATIONS GRADING SWERVlSlON PERC TESTING mvrmmmmu rrnmnmnm PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 9 BLACK RAIL ROAD, CARLSBAD SEPTEMBER 27,2002 4. Fill Materials and Compaction: Removed soils may be reused as site compacted fills and backfills provided all unsuitable materials and vegetation are selectively separated and removed to the satisfaction of the project geotechnical engineer. Fill soils should be clean deposits free of vegetation, roots, debris, deleterious matter or rock sizes greater than 6 inches in maximum diameter. Import soils, if used to complete grading or achieve design grades, should be non-expansive sandy granular soils (expansion index less than 21), inspected, tested as necessary and approved by the project geotechnical consultant prior to the delivery to the site. Uniform bearing soil conditions should be constructed at the site by the remedial grading and ground preparation operations. Site tills/backfills should be adequately processed, thoroughly mixed, moisture conditioned to near optimum moisture levels, placed in thin uniform horizontal lifts and mechanically compacted to a minimum of 90% of the corresponding laboratory maximum dry density (ASTM D-I 557) unless otherwise specified. 5. Surface Drainage and Erosion Control: A critical element to the continued stability of the graded building surfaces is an adequate drainage system. This can most effectively be achieved by installation of appropriate drainage facilities, per the project civil engineerlarchitect design. Building pad surface run-off should be collected and directed to a selected location in a controlled manner. Area drains should be installed. In no case should water be allowed to pond or accumulate adjacent to the improvements and structures. Site drainage over the finished surfaces should flow away onto suitable locations in a positive manner. Care should be taken during the construction, improvements, and final construction phases not to disrupt the designed drainage patterns. 6. Engineering Inspections: All remedial grading and ground preparations including removals, suitability of earth deposits used as compacted fill/backfill and compaction procedures should be continuously inspected and tested by the project geotechnical consultant and presented in the final as-graded compaction report. The nature of finish foundation bearing and subgrade soils should also be confirmed in the final compaction report at the completion of grading. VINJE @ MIDDLETON ENGINEERING, INC. 2450 vinyard he, Y.102, E~condido, CoLfmnia 92029.1229 * Phar f760) 743.1214 Fa (760) 739.0343 GRADING SUPERVISION PERC TESTING ENVIRONMENTAL lNV€WlGATIONS GEOTECHNICAL INVESTIGATIONS PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 10 BLACK RAIL ROAD, CARLSBAD SEPTEMBER 27,2002 Geotechnical engineering inspections shall include but not limited to the following: Initial Inspection - After the gradinglbrushing limits have been staked, but before gradinglbrushing starts. Bottom of over-excavation inspection - After Terrace Deposits or firm native ground (in-place densities above 90%) is exposed and prepared to receive fill, but before fill is placed. Exposed bottom of all removals and over-excavations should be additionally prepared as directed in the field. Filllbackfill inspection -After the filllbackfill placement is started, but before the vertical height of fill/backfill exceeds 2 feet. A minimum of one test shall be required for each 100 lineal feet maximum, with the exception of wall backfills where a minimum of one test shall be required for each 25 lineal feet maximum. Finish rough and final pad grade tests shall be required regardless of fill thickness. * * * * Foundation trench inspection - After the foundation trench excavations, but before steel placement. Foundation bearinglslab subgrade soils inspection - Within 72 hours prior to the placement of concrete for proper moisture and specified compaction levels. Geotechnical foundationlslab steel inspection - After steel placement is completed, but 24 hours before the scheduled concrete pour. Subdrainhvall back drain inspection -After the trench excavation, but during the actual placement. All material shall conform to the project material specifications and be approved by the project geotechnical engineer. Underground utility trench inspection - After the trench excavations, but before installation of the underground facilities. Local and CAL-OSHA safety requirements for open excavations apply. Inspection of the bottom of the trench and pipe bedding may also be required by the project geotechnical engineer. Underground utility trench backfill inspection - After the backfill placement is started above the pipe zone, but before the vertical height of backfill exceeds 2 feet. Testing of the backfill within the pipe zone, may also be required by the * * * * * VlNJE 6, MIDDLETON ENGINEERING, INC. 2450 Vi-rd Awturo, $102, Escadido. clllifmn*r 92029,1229 Phav (760) 743.1214 * Fa (7601 739.0343 FEOTECHNICAL INYESTIFATIONS FRADlNF SUPERVISION PERC TESTIN0 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 11 BLACK RAIL ROAD, CARLSBAD SEPTEMBER 27,2002 governing agencies. Pipe bedding and backfill materials shall conform to the governing agencies requirements and project soils report if applicable. All trench backfills shall be mechanically compacted to a minimum of 90% compaction levels unless otherwise specified. All trenches over 12 inches deep maximum under the interior floor slabs should also be mechanically compacted and tested for a minimum of 90% compaction levels. Flooding or jetting techniques as a means of compaction method shall not be allowed. Improvement subgrade inspections - Within 72 hours prior to the placement of finish surface for proper moisture and specified compaction levels. B. Foundations and Slab-on-Grades The following recommendations are consistent with very low expansive (El less than 21) silty sand (SM) bearing soil expected at finish grades. Final designs should be confirmed and/or revised as necessary in the rough grading compaction report based on site as-graded geotechnical conditions and actual testing of the foundation bearing and subgrade soils. 1. Continuous strip foundations should be a minimum of 15 inches wide and 18 inches deep. Spread pad foundations, if any, should be a minimum of 24 inches square and 12 inches deep. Exterior continuous footings should enclose the entire building perimeter. 2. Continuous interior and exterior foundations should be reinforced with a minimum of 44 reinforcing bars. Place 2-M bars 3 inches above the bottom of the footing and 24 bars 3 inches below the top of the footing. Reinforcement details for spread pad footings should be provided by the project architecffstructural engineer. 3. Commerciallindustrial floors on very low expansive subgrade soils which support machinery loads should be a minimum of 5 inches in thickness, reinforced with #4 reinforcing bars spaced 18 inches on center each way, placed mid-height in the slab. The slabs may be underlain by 4 inches of clean sand (SE 30 or greater) and provided with a 6-mil plastic moisture barrier placed mid-height in the sand. In the case of good quality sandy subgrade soils and as approved by the project geotechnical engineer, the 6-mil plastic moisture barrier may be laid directly over the slab subgrade and covered with a minimum of 2 inches of clean sand as specified. The sand underlayment and/or plastic moisture may be deleted in the case of non-moisture sensitive floors. VINJE B MIDDLETON ENGINEERING, INC. 2450 Vinqd Aymwe, Y102, Eieandido, Cdifmnh 92029.1229 * Phrmr (7601 743.1214 Fax (760) 739.0343 GEOTECHNICAL INVETTlGATlONS GRADINQ SUPERVISION PERC TESTINQ ENVIRONMENTAL IWESTIQATIONS !- ... PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 12 BLACK RAIL ROAD, CARLSBAD SEPTEMBER 27,2002 Actual slab design should be evaluated, confirmed or revised as necessary by the project structural engineer based on the design loads. A soil module of subgrade reaction of 200 pci may be considered. 4. Control joints in commerciallindustrial floor slabs should be provided, per the structural design. In general, slabs may be provided with “soft-~t” contractionlcontrol joints consisting of sawcuts spaced 10 feet on center maximum each way for all interior slabs. Cut as soon as the slab will support the weight of the saw, and operate without disturbing the final finish which is normally within 2 hours after final finish at each control joint location, or 150 psi to 800 psi. The softcuts should be a minimum of I-inch in depth, but not to exceed 1%-inches. Anti-ravel skid plates should be used and replaced with each blade to avoid spalling and raveling. Avoid wheeled equipment across cuts for at least 24 hours. 5. Provide re-entrant corner reinforcement for all interior slabs. Re-entrant corners will depend on slab geometry and/or interior column locations. Plate 5 may be used as a general guideline. 6. Foundation trenches and slab subgrade soils should be inspected and tested for proper moisture and specified compaction levels, and approved by the project geotechnical consultant within 72 hours prior to the placement of concrete. C. E-s 1. All exterior slabs (walkways, and patios) should be a minimum of 4 inches in thickness, reinforced with 6x6/1OxlO welded wire mesh carefully placed mid- height in the slab. 2. Provide “tool joint” or “soft-cut’’ contraction/control joints spaced 10 feet on center maximum each way. Tool or cut as soon as the slab will support weight, and operate without disturbing the final finish which is normally within 2 hours after final finish at each control joint location or 150 psi to 800 psi. The tool or softcut joints should be a minimum of I-inch in depth but not to exceed 1 %- inches. In case of softcut joints, anti-ravel skid plates should be used and replaced with each blade to avoid spalling and raveling. Avoid wheeled equipments across cuts for at least 24 hours. 3. Subgrade soils should be tested for proper moisture and a minimum of 90% compaction levels, and approved by the project geotechnical consultant within 72 hours prior to the placement of concrete. - VINJE t7 MIDDLETON ENGINEERING, INC. 2450 Vineyard hue, 1102, Eseandida, Cdif-i~ 92029.1229 * Phar (7601 743-1214 Fa (760) 739.0343 GEOTECHNICAL INYESTIGATIONS GRADING SUPERVISION PERC TESTING ENVIRONMENI’AL lNVESTlGATIONS i , .- PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 13 BLACK RAIL ROAD, CARLSBAD SEPTEMBER 27,2002 D. Soil Desian Parameters The following site specific soil design parameters are based upon characteristics of tested soil samples and our experience with similar deposits. All parameters should be confirmed when the characteristics of the final as-graded soils have been specifically determined: * * * * * * * * Design wet density of soil = 129.4 pcf. Design angle of internal friction of soil = 31 degrees. Design active soil pressure for retaining structures = 40 pcf (EFP), level backfill, cantilever, unrestrained walls. Design at-rest soil pressure for retaining structures = 62 pcf (EFP), non- yielding, restrained walls. Design passive soil pressure for retaining structures = 414 pcf (EFP), level surface at the toe. Design coefficient of friction for concrete on soil = 0.38. Net allowable foundation pressure = 2000 psf, minimum 15 inches wide by 18 inches deep footings. Design allowable lateral bearing pressure (all structures except retaining walls) = 200 psfm . Notes: 1. Use a minimum safety factor of 1.5 for wall over-turning and sliding stability. However, because large movements must take place before maximum passive resistance can be developed, a minimum safety factor of 2 may be considered for sliding stability particularly where sensitive structures and improvements are planned near or on top of retaining walls. 2. When combining passive pressure and frictional resistance, the passive component should be reduced by one-third. 3. The indicated net allowable foundation pressure provided herein was determined based on the specified foundation width and depth and may be increased by 20% for each additional foot of depth and width to a maximum of 4500 psf. The net allowable foundation pressure provided herein also applies to dead plus live loads and may be increased by one-third for wind and seismic loading. 4. The lateral bearing earth pressures may be increased by the amount of the designated value for each additional foot of depth to a maximum of 1500 pounds per square foot. - VINJE 6, MIDDLETON ENGlNEERING, INC. 2450 Vi-rd Awn=, 1102. Essandido, Calif.mi. 92029.1229 * Phmv 17-91 743.1214 - Fax 1760) 739.0343 ~EOTECHNICAL INVESTIGATIONS GRADING SUPERVISION PERC TESTING ENVIRONMMTAL INYESTIGATIONS ,. .- PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 14 BLACK RAIL ROAD, CARLSBAD SEPTEMBER 27,2002 E. General Recornrnen dations 1. The minimum foundation/slab design and steel reinforcement provided herein is based upon soil characteristics only and is not intended to be in lieu of reinforcement necessary for structural considerations. All recommendations should be evaluated and confirmed by the project architectlstructural engineer. 2. Adequate staking and grading control is a critical factor in properly completing the recommended remedial and site grading operations. Grading control and staking should be provided by the project grading contractor or surveyor/civil engineer and is beyond the geotechnical engineering services. Inadequate staking and/or lack of grading control may result in unnecessary additional grading which will increase construction costs. 3. Final plans should reflect preliminary recommendations given in this report. Final plans may be submitted to the project geotechnical consultant for review and conformance with the soils report. Additional recommendations should be provided at that time if it becomes necessary. 4. All foundation trenches should be inspected to ensure adequate footing embedment and confirm competent bearing soils. Foundation and slab reinforcements should be inspected and approved by the project geotechnical consultant. 5. All underground utility trenches should be mechanically compacted to a minimum of 90% of the maximum dry density of the soil unless otherwise specified. Care should be taken not to crush the utilities or pipes during the compaction of the soil. Non-expansive, granular backfill soils should be used. 6. Expansive clayey soils should not be used for backfilling of any retaining structure. All retaining walls should be provided with a 1:l wedge of granular, compacted backfill measured from the base of the wall footing to the finished surface. Retaining walls should be provided with a back drainage in general accordance with the enclosed Plate 6. 7. Site drainage should flow away from structures in a positive manner. Care should be taken during the construction, improvement, and fine grading phases not to disrupt the designed drainage patterns. Rooflines of the building should be provided with roof gutters. Roof water should be collected and directed away from the buildings to a suitable location. - VlNJE B MIDDLETON ENGINEERING, INC. 2450 vi-d Awwr, #102, &condido. Cdlifmnin 92029.1229 Phav (760) 743-1214 Fa (760J 739.0343 GEOTECHNICAL INVESTIGATIONS GRALXNG SUPERVISION PERC TEETINO ENVIRONMENTAL INVESTlGATlOh'S PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 15 BLACK RAIL ROAD, CARLSBAD SEPTEMBER 27,2002 8. The amount of shrinkage and related cracks that occurs in the concrete slab- on-grades and flatworks depends on many factors, the most important of which is the amount of water in a concrete mix. The purpose of the slab reinforcement is to keep normal concrete shrinkage cracks closed tightly. The amount of concrete shrinkage can be minimized by reducing the amount of water in the mix. To keep shrinkage to a minimum, the following should be considered: * Use the stiffest mix that can be handled and consolidated satisfactorily. * Use the largest maximum size of aggregate that is practical, (for example, concrete made with %-inch maximum size aggregate usually requires about 40 Ibs more (nearly 5 gal.) water per cubic yard than concrete with I-inch aggregate). Cure the concrete as long as practical. * The amount of slab reinforcement provided for conventional slab-on-grade construction considers that good quality concrete materials, proportioning, craftsmanship, and control tests where appropriate and applicable are provided. 9. A preconstruction meeting between representatives of this office and the property owner or planner, as well as the generaVgrading contractor, is recommended in order to discuss grading/construction details associated with proposed development. VII. LIMITATIONS The conclusions and recommendations provided herein have been based on a review of pertinent reports ans plans, all available data obtained from our field investigation and laboratory analyzes, as well as our experience with the soils and formational materials located in the general area. The materials encountered on the project site and utilized in our laboratory testing are believed representative of the total area; however, earth materials may vary in characteristics between excavations. Of necessity we must assume a certain degree of continuity between exploratory excavations and/or natural exposures. It is necessary, therefore, that all observations, conclusions, and recommendations be field verified during the grading operation. In the event discrepancies are noted, we should be contacted immediately so that an inspection can be made and additional recommendations issued if required. The recommendations made in this report are applicable to the site at the time this report was prepared. It is the responsibility of the owner/developer to ensure that these recommendations are carried out in the field. - VINJE ff MIDDLETON ENGINEERINF, INC. 2450 Vineyard Avenue, Y102, Escadido, Califmnh 92029.1229 Phav (760) 743-1214 Fa (760) 739.0343 PERC TESTING ENVIRONUEhTN IWESTlGATIONS OFOTECHNICAL INVESTIGATIONS GRMING SUPERVISION ! !,,- I -.. ,- PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 16 BLACK RAIL ROAD, CARLSBAD SEPTEMBER 27,2002 It is almost impossible to predict with certainty the future performance of a property. The future behavior of the site is also dependent on numerous unpredictable variables, such as earthquakes, rainfall, and on-site drainage patterns. The firm of VlNJE & MIDDLETON ENGINEERING, INC. shall not be held responsible for changes to the physical conditions of the property such as addition of fill soils, added cut slopes, or changing drainage patterns which occur without our inspection or control. This report should be considered valid for a period of one year and is subject to review by our firm following that time. If significant modifications are made to your tentative development plan, especially with respect to the height and location of cut and fill slopes, this report must be presented to us for review and possible revision. Vinje & Middleton Engineering, Inc. warrants that this report has been prepared within the limits prescribed by our client with the usual thoroughness and competence of the engineering profession. No other warranty or representation, either expressed or implied, is included or intended. Once again, if any questions arise concerning this report, please do not hesitate to contact this office. Reference to our Job #02-204-P will help to expedite our response to your inquiries. We appreciate this opportunity to be of service to you. VINJE & MIDDLETON ENGINEERING, INC. - 23- ,) .- Steven J. Melzer < 1 W v ~- RG#6953 DM/SMSS/SJM/jt Distribution: Addressee (5) VINJE B MIDDLETON ENGINEERlh’G, INC. 2450 Vinmzrd Awnt ~ ~ ~____ GRADING SUPERVISION PERC TESTIN0 FNYIBONMRJr*I IrnnAITIAUC GEOTECHNICAL IWESTIQATIONS I. EXPLANATION Approximate Location of Test Pit -. ~~ PRIMARY DIVISIONS CLEAN GRAVELS (LESS THAN 5% FINES) - GRAVEL WITH FINES CLEAN SANDS (LESS THAN 5% FINES) SANDS WiTH EIUCe GRAVELS MORE THAN HALF OF COARSE FRACTION IS GROUP SECONDARY DIVISIONS SYMBOL GW GP GM GC sw SP SM SC Well graded gravels. gravel-sand mixtures. little or no fines. Poorly graded gravels or gravel-sand mixtures, little or no fines. Silty gravels. gravei.sand-silt mixtures. nondastlc fines. Clayey gravels. gravel-sand-clay mixtures, plastic fines. Well graded sands, gravelly sands, little or no fines. Poorly graded sands or gravelly sands, little or no fines. Silty sands, sand-silt mixtures, non.plastic fines. Clayey sands, sand-clay mixtures. plastic fines. LARGER THAN NO. 4 SIEVE SANDS SlLTS AN0 CLAYS LIQUID LIMIT IS LESS THAN 50% SILTS AND CLAYS LlQUiD LIMIT IS GREATER THAN 50% MORE THAN HALF OF COARSE FRACTION IS SMALLER THAN NO. 4 SIEVE ML CL OL MH CH OH Inorganic silts and very fine sands, rock flour. silty or clayey fine Inorganic clays of low to medium plasticity, gravelly clays, sandy Organic silts and organic silty clays of low plasticity. Inorganic silts, micaceous or diatomaceous fine sandy or silty Inorganic clays of high plasticity, fat ciays. Oraanic clavs of medium to hiah OlaStiCitV. omanlc silts. sands or clayey silts with slight plastlcity. clays, silty clays, lean clays. - soils. elastic silts. SAND SILTS AND CLAYS FINE MEDIUM COARSE GRAVEL .COBBLES BOULDER! FINE COARSE HIGHLY ORGANIC SOILS [ PT 1 Peat and other highly organic soils. ;ANDs. GRAVELS AND NON-PLASTIC SILTS BLOWS,FOOT RELATIVE DENSITY STRENGTH CLAYS AND PLASTIC SILTS BLOWS/FOOT VERY SOFT CONSISTENCY 0-% 0.2 VERY LOOSE LOOSE MEDIUM DENSE DENSE VERY DENSE 0-4 4-10 10.30 30.50 OVER 50 SOFT FIRM STIFF VERY STIFF HARD I. Blow count, 140 pound hammer falling 30 inches on 2 inch O.D. split spoon sampler (ASTM D-1586) 2. Unconfined compressive strength per SOILTEST pocket penetrometer CL-700 %-x 2-4 %-I 4-8 1-2 6-16 2.4 16-32 OVER 4 OVER 32 I 246 = Standard Penetration Test (SPT) (ASTM D-1 566) Sand Cone Test Bulk Sample with blow counts per 6 inches PROJECT NO. c] Chunk Sample 0 Driven Rings I I 246 = California Sampler with blow counts per 6 inches i KEY TO EXPLORATORY BORING LOGS Unified Soil Classification System (ASTM D-2487) VINJE & MIDDLETON ENGINEERING, INC. KEY Date: uscs SYMBOL Date: FIELD MOISTURE 0%) 8-28-02 - SAMPLE - 0 0 0- T-1 DESCRIPTION ~ ~ ~~ TOPSOIL: Silty fine sand. Red-brown color. Dry to moist. Loose. Abundant rootlets. ST-I TERRACE DEPOSITS: Sandstone. Fine to medium arained. Red-brown color. Dry to moist. Dense. Weathered friable. Cemented. No apparent structure. Scattered pebbles. ST-2 End Test Trench at 3%'. No caving. No groundwater. Logged by:' SJE -- FIELD DRY DENSITY (pa) 123.9 118.2 117.9 RELATIVE COMPACT10 00 DEPTH (fit - .- .I - .2 - .3- -4 - 5- 6- 7- 8- .- .- .- .- .- - - DESCRIPTION SAMPLE USCS 5YMBOL Logged by: RELATIVE COMPACTION 1%) VINJE & MIDDLETON ENGINEERING, INC 2450 Vineyard Avenue, Suite 102 Bulk Sample 0 Chunk Sample 0 Driven Rings V Sand Cone Test . ............. \ 30 MILES FAULT - EPICENTER MAP SAN DIEGO COUNTY REGION INDICATED EARTHQUAKE EVENTS THROUGH 75 YEAR PERIOD (1900-1974) This Map data is compiled from varlous sources including the California Division of Mines and Geology, California Institute of Technology, and the National Oceanic and Atmospheric Administration. This Map is reproduced from the California Division of Mines and Geology, “Earthquake Epicenter Map of California: Map Sheet 39.” Eehquake Magnitude 1 ............ 2 4.0 TO 4.9 8 .........a 5.0 TO 5.9 ........... 6.0 TO 6.9 7.0 TO 7.9 ..-..., PROJECT Job #02-304-P BI ACK RA IL ROAD. CAR LSBAD +- --A Fault PLATE: 4 - c ISOLATION JOINTS AND RE-ENTRANT CORNER REINFORCEMENT Typical - no scale ISOLATION JOINTS CONTRACTION JOINTS I. -RE-ENTRANT . CORNER CRACK RE-ENTRANT CORNER -L REINFORCEMENT NO. 4 BARS PLACED 1.5'' BELOW TOP OF SLAB NOTES: 1. Isolation joints around the columns should be either circular as shown in (a) or diamond shaped as shown in (b). If no isolation joints are used around columns, or if the corners of the isolation joints do not meet the contraction joints, radial cracking as shown in (c)may occur (reference ACI), 2. In order to control cracking at the re-entrant corners (f270' corners), provide reinforcement as shown in (c). 3. Re-entrant corner reinforcement shown herein is provided as a general guideline only and is subject to verification and changes by the project architect and/or structural engineer based upon slab geometry, location, and other engineering and construction factors. VINJE & MIDDLETON ENGINEERING, INC. PLATE 5 RETAINING WALL DRAIN DETAIL Typical - no scale filter fabric) or Class 2 Permeable Material (see specifications below) i Perforated drain pipe Competent, approved soils or bedrock 1. Provide granular, non-expansive backfill soil in 1:l gradient wedge behind wan. Compact backfill to minimum 90% of laboratory standard. 2. Provide back drainage for wall to prevent build-up of hydrostatic pressures. Use drainage openings along base of wail or back drain system as outlined below. 3. Backdrain should consist of 4" diameter PVC pipe (Schedule 40 or equivalent) with perforations down. Drain to suitable outlet at minimum 1%. Provide %" - 1%" crushed gravel filter wrapped in fiiter fabric (Mirafi 140N or equivalent). Deietefiter fabrh wrap it CaRrans Class 2 permeable material is used. Compact Class 2 material to minimum 90% of laboratory standard. 4. Seal back of wall with waterproofing in accordance with architeds spedcations. 5. Provide positive drainage to disallow ponding of water above wail. Lined drainage ditch to minimum 2% flow awayfrom wall is recommended, * Use 1 % cubic foot Per foot with granular backfill soil and 4 cubic foot per foot if expansive backfill soil is used VINJE & MIDDLETON ENGINEERING, INC. PLATE 6