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Home My WebLink About20 Civic Center Plaza - Soils ReportECEIVED APR 2 7 1998 City of Santa Ana LAW Crandall LAWGIBB Group Member 1 REPORT OF GEOTECHNICAL INVESTIGATION PROPOSED PLANNING AND BUILDING AGENCY BUILDING SANTA ANA BOULEVARD AND ROSS STREET SANTA ANA, CALIFORNIA Prepared for: GRIFFIN REALTY SA, INC. Santa Ana, California July 8, 1997 Project 70131-7-0261.0001 I DI I1042- r-?J 31.rap 42 0 <yz LAW Crandall LAWGIBB Group Member A July 8,1997 Mr. Roger Nello Torriero Griffin Realty SA, Inc. 6 Hutton Center Drive, Suite 820 Santa Ana, California 92707 Subject:Report of Geotechnical Investigation Proposed Planning and Building Agency Building Santa Ana Boulevard and Ross Street Santa Ana, California Law/Crandall Project 70131-7-0261.0001 Dear Mr. Torriero: We are pleased to submit the results of our geotechnical investigation for the proposed Planning and Building Agency building to be constructed at Santa Ana Boulevard and Ross Street in Santa Ana, California. This investigation was conducted in general accordance with our proposal dated May 27,1997, as authorized by you on May 27,1997. The results of our investigation and design recommendations are presented in this report. Please note that you or your representative should submit copies of this report to the appropriate governmental agencies for their review and approval prior to obtaining a building permit. We are performing a Phase 1 environmental site assessment of the site of the proposed building. The results of the assessment will be submitted under separate cover. LAW Engineering and Environmental Services, Inc. 200 Citadel Drive Los Angeles, CA 90040-1554 213-889-5300 Â· Fax. 213-721-6700 Grifin Realty SA, Inc. - Geotechnical Investigation Law/Crandall Project 70131-7-0261.0001 July 8,1997 It is a pleasure to be of professional service to you on this project. Please call if you have any questions or require additional information. Sincerely, LAW/CRANDALL *:EAAEL H, ,{Di No. 54974 Exp.6-30-00 Michael W. Han CCe/#ACVLVT Staff Engineer -1.=M-QMS,0, < No. 2371 MI No. 2087 Paul R. Schade 1*\ Exp. 9/30/00 fj Jake Kliafraz - '- - * Exp. 9-30-99 *Senior Engineer Principal Engineer TECHN\43-e n g g e o \ 9 7 - p roj \ 7 0 2 61 \0 2 6 1 1 RO 1' B i * I..j NtÂ£23/ (3 copies submitted) 32 CC:John A. Martin & Associates, Inc. Attn: Mr. Chuck Whitaker McLarand, Vasquez & Partners, Inc. Attn: Mr. Jim Mittendorf REPORT OF GEOTECHNICAL INVESTIGATION PROPOSED PLANNING AND BUILDING AGENCY BUILDING SANTA ANA BOULEVARD AND ROSS STREET SANTA ANA, CALIFORNIA Prepared for: GRIFFIN REALTY SA, INC. Santa Ana, California Law/Crandall Los Angeles, California July 8, 1997 Project 70131-7-0261.0001 Gri#in Realty SA, Inc.-Geotechnical Investigation Law/Crandall Project 70131-7-0261.0001 July 8.1997 TABLE OF CONTENTS Eagg LIST OF FIGURFR It! SUMMARY iv 1.0 SCOPE 1 2.0 PROJECT DESCRIPTION 2 3.0 SITE CONDITIONS 3 4.0 EXPLORATIONS AND LABORATORY TESTS 3 5.0 SOIL CONDITIONS 4 6.0 RECOMMENDATIONS 4 6.1 FOUNDATIONS 5 6.2 SITE COEFFICIENT AND SEISMIC ZONATION 7 6.3 EXCAVATION AND SLOPER 7 6.4 SHORING 8 6.5 WALLS BELOW GRADE 13 6.6 FLOOR SLAB SUPPORT 14 6.7 PAVING 15 6.8 GRADING 16 6.9 GEOTECHNICAL OBSERVATION 17 7.0 BASIS FOR RECOMMENDATIONS 18 APPENDIX A:EXPLORATIONS AND LABORATORY TESTS APPENDIX B:SOIL CORROSIVITY STUDY BY M.J. SCHIFF AND ASSOCIATES It Gri#in Really SA, Inc.-Geotechnical Investigation Law/Crandall Project 70131-7-0261.0001 July 8, 1997 1 LIST OF FIGURES 1 Site Plan 2 Drilled Pile Capacities 1 1 1 1 1 1 1 1 1 1 lili Gri#in Realry SA, Inc.-Geotechnical Investigation Law/Crandall Project 70131-7-0261.0001 July 8, 1997 SUMMARY We have completed our geotechnical investigation of the site of the proposed Planning and Building Agency building in Santa Ana, California for Griffin Realty SA, Inc. Our subsurface explorations, engineering analyses, and foundation design recommendations are summarized below. We explored the soil conditions by drilling two borings at the site; fill soils, 2 and 3 feet thick, were found in the two borings. The natural soils consist of sandy silt, clayey silt, silty sand and sand. To supplement our current geotechnical analyses, we also reviewed our report of foundation investigation, dated November 7, 1958, for the existing on-site police building which will be demolished. The geotechnical recommendations in this report were developed in part using information from our previous investigation. The existing fill soils are not suitable for support of the proposed building foundations and fioor slab. The natural soils consist primarily of medium stiffsilt, with minor deposits of dense sand and silty sand. The upper natural soils become considerably weaker and more compressible when wet. Water was encountered at depths of 65'h and 67'h feet below the existing grade. To provide support for the proposed building with minimum settlement, drilled cast-in-place concrete piling may be used. We understand that the drilled cast-in-place piles for the existing police building will be left in-place but will not be used for support of the new building. The on- site soils are suitable for use as compacted fill, and the building floor slab can be supported on grade. iv Gri#in Realry SA, Inc.-Geotechnical Investigation Uiw/Crandall Project 70131-7-0261.0001 July 8, 1997 1.0 SCOPE This report provides foundation design information for the proposed Planning and Building Agency building in Santa Ana, California. The locations of the existing building and our exploration borings are shown in Figure 1, Site Plan. We submitted the results of our foundation investigation at the site for the existing police building in a report dated November 7, 1958 (our Job No. 58338). The locations of our previous exploration borings are shown in Figure 1. The recommendations presented in this report were developed in part using geotechnical information from our previous investigation. This investigation was authorized to determine the static physical characteristics of the soils at the site of the proposed building, and to provide recommendations for foundation design, floor slab support, and for grading for the proposed development. We were to evaluate the existing soil and groundwater conditions at the site, including the corrosion potential of the soils, and develop recommendations for the following: â€¢ Design of new foundations to be used for support of the proposed building, including allowable increases for wind or seismic loads, estimated settlements for the anticipated loadings, and frictional and passive values for the resistance of lateral forces. â€¢ Subgrade preparation and floor slab support. â€¢ Design of walls below grade and retaining walls. â€¢ Design of shoring. â€¢ Subgrade preparation and design of asphalt and Portland cement concrete paving. â€¢ Grading, including site preparation, excavation and slopes, the placing of compacted fill, and quality control measures relating to earthwork. In addition. corrosion studies were performed by M.J. Schiff and Associates, Inc., Consulting Corrosion Engineers. The results of the studies are presented in Appendix B. 1 Griffin Realty SA, Inc.-Geotechnical investigation Law/Crandall Project 70131-7-0261.0001 July 8, 1997 The scope of this investigation did not include geologic or seismic studies for the site. Accordingly, our conclusions and recommendations are for static loading conditions only: however, this does not imply that there is a geologic or seismic hazard affecting the site. Our recommendations are based on the results of our current and previous field explorations, laboratory tests, and appropriate engineering analyses. The results of the current and previous field explorations and laboratory tests, which form the basis of our recommendations, are presented in Appendix A. Our professional services have been performed using that degree of care and skill ordinarily exercised, under similar circumstances, by reputable geotechnical consultants practicing in this or similar localities. No other warranty, expressed or implied, is made as to the professional advice included in this report. This report has been prepared for Griffin Realty SA, Inc. and their design consultants to be used solely in the design of the proposed Planning and Building Agency building. The report has not been prepared for use by other parties, and may not contain sufficient information for purpose of other parties or other uses. 2.0 PROJECT DESCRIPTION Griffin Really SA plans to redevelop a portion of the civic center area for the Public Works Agency and the Planning and Building Agency following the relocation of the City Police Department into new facilities. It is planned to demolish the former Police Department building at the site and construct a new Planning and Building Agency building totaling approximately 30,000 gross square feet. The location of the proposed building has not been determined, however, the proposed building is anticipated to be two stories above grade. The proposed building may be underlain by one subterranean level that will utilize and extend beyond the existing basement of the Police Department building. 2 Grifin Really SA, Inc.-Geotechnical Investigation Unv/Crandall Project 70131-7-0261.0001 July 8, 1997 3.0 SITE CONDITIONS The site is located northeast of the Santa Ana City Hall building in the Civic Center area. The site is currently occupied by the former Police Department building and a surface parking lot. The Police Department building is currently vacant and is two stories high and underlain by one subterranean level. The existing building extends over a ramp that connects the existing grade to a subterranean parking level that is located adjacent to the west side of the existing building. If a subterranean parking level is not constructed, the existing basement will be backfilled. The existing building is supported on pile foundations and we understand that the existing piles wili be left in-place and will not to be used for support of the proposed building. An on grade annex building is located at the southwest corner ofthe existing building. 4.0 EXPLORATIONS AND LABORATORY TESTS The soil conditions beneath the site were explored by drilling two borings to depths of 68'h and 70 feet below the existiAg grade at the locations shown in Figure 1. Data were also available from our previous investigation at the site (our Job No. 58338). Details of the current and prior explorations and the logs of the borings are presented in the Appendix A. Laboratory tests were performed on selected samples obtained from the borings to aid in the classification of the soils and to determine the pertinent engineering properties of the foundation soils. The following tests were performed: â€¢ Moisture content and dry density determinations. â€¢ Direct shear. â€¢ Consolidation. â€¢ Hydroconsolidation. â€¢ Compaction. All testing was done in general accordance with applicable ASTM specifications. Details of the laboratory testing program and test results are presented in the Appendix. 3 Gri#in Realty SA, Inc.-Geotechnical Investigation Law/Crandall Project 70131-7-0261.0001 July 8,1997 5.0 SOIL CONDITIONS' Fill soils, 2 and 3 feet thick, were found in the two current borings. The fill soils consist of silty sand and are not uniformly well compacted. Deeper fill could occur between borings and especially adjacent to the existing basement walls. The natural soils consist of silly sand, sandy silt, clayey silt, and sand. The silty soils throughout the depth explored are variable in strength and compressibility, ranging from soft and compressible to medium stiff. The upper silty soils will become weaker and more compressible when wet. The sand and silty sand deposits are generally dense. Water was encountered at depths of 65'/1 and 67'6 feet below the existing grade. The corrosion studies indicate that the on-site soils are moderately corrosive to ferrous metals and non-deleterious to Portland cement concrete. The report of corrosion studies presented in Appendix B should be referred to for a discussion of the corrosion potential of the soils, and for potential mitigation measures. 6.0 RECOMMENDATIONS The existing fill soils are not considered suitable for support of the proposed building foundations and floor slab. The natural silty soils at the site are soft to medium stiff and compressible. Because of settlement considerations, the use of conventional spread footings is not recommended for the support of the proposed building. Accordingly, we recommend that the proposed building be supported on drilled cast-in-place friction piles. If the recommendations on grading are followed, the floor slab can be supported on grade. If a subterranean level is to be constructed, excavation of about 15 feet below the existing grade will be required. The excavation should be either sloped back and/or shored. Care should be taken in excavating adjacent to the existing buildings to the west to avoid undermining the existing footings and slabs. 4 Griffin Realm SA, inc.-Geotechnical Investigation Law/Crandal! Project 70131-7-0261.0001 July 8, 1997 .. 6.1 FOUNDATIONS Drilled Pile Capacities The downward and upward capacities 6f 18-, 24-, and 30-inch-diameter drilled piles are presented as a function of penetration below pile caps in Figure 2, Drilled Pile Capacities. Dead plus live load capacities are shown; a one-third increase may be used for wind or seismic loads. The capacities presented are based on the strength of the soils; the compressive and tensile strength of the pile sections should be checked to verify the structural capacity of the piles. Piles in groups should be spaced at least 20 diameters on centers. If the piles are so spaced, no reduction in the downward capacities need be considered due to group action. Settlement Although foundation load information is not available, we estimate the settlement of the proposed building, supported on drilled piling in the manner recommended, will be less than 'h inch. Differential settlement between adjacent columns is expected: to be about 'A inch or less. Lateral Loads Lateral loads can be resisted by the piles, by soil friction on the floor slab, and by the passive resistance of the soils. The soils adjacent to a 24-inch-diameter pile, at least 20 feet long, can resist horizontal loads imposed at the top of the pile of up to 20,000 pounds. The lateral resistance of other sizes of piles may be assumed to be proportional to the diameter. In calculating the bending moment in a pile, the lateral load imposed at the top of the pile may be multiplied by a moment arm of 5 feet. For design, it may be assumed that the maximum bending moment will occur near the top of the pile and that the moment will decrease to zero at a depth of 20 feet below the pile cap. The lateral capacity and reduction in the bending moment are based in part on the assumption that any required backfill adjacent to the pile caps and grade beams will be properly compacted. 5 Grifin Really SA, Inc.-Geolechnical Investigation Law/Crandall Project 70131-7-0261.0001 July 8. 1997 A coefficient of friction of 0.4 can be used between the fioor slab and the supporting soils. The passive resistance of natural soils or properly compacted fill soils can be assumed to be equal to the pressure developed by a fluid with a density of 300 pounds per cubic foot. A one-third increase in the passive value can be used for wind or seismic loads. The frictional resistance and the passive resistance of the soils can be combined without reduction in determining the total lateral resistance. Installation All drilled pile excavations should be observed by personnel of our firm. Because of the sandy soils, minor difficulties should be anticipated in drilling the pile shafts because of caving. Water was encountered at depths of 65'/1 and 67'/1 feet below grade. Accordingly, pile tip evaluations will be established above the water level. Also, due to the sandy layers, localized water seepage zones may occur above the groundwater levels encountered in our exploration borings. Depending on the typeof drilling equipment used by the contractor, some caving and raveling will occur within the pile shafts during drilling. Precautions should be taken during the installation of the piles to reduce caving and raveling. Among other precautions, the drilling speed should be reduced as necessary to minimize vibration and sioughing of the sand deposits. Closely spaced piles should be drilled and filled alternately, with the concrete permitted to set at least eight hours before drilling an adjacent hole. Pile excavations should be filled with concrete as soon after drilling and inspection as possible; the holes should not be left open overnight. The concrete should be placed with special equipment so that the concrete is not allowed to fall freely more than 5 feet and to prevent concrete from striking the walls of the excavations. Spread Footings for Minor Structures Spread footings, for minor structures, established in the undisturbed natural soils andjor properly compacted fill soils may be designed to impose a net dead plus live load pressure of 2,000 pounds per square foot. A one-third increase in the quoted bearing value may be used when considering 6 Grijlin Really SA, Inc.-Geotechnical Investigation Law/Crandall Project 70131-7-0261.0001 July 8. 1997 wind of seismic loads. Footings should extend at least 2 feet below the adjacent final grade. Since the recommended bearing value is a net value, the weight of concrete within the footings may be taken as 50 pounds per cubic foot, and the weight of soil backfill may be neglected when determining the downward load on the footings. A coefficient of friction of 0.4 can be used between the floor slab and the supporting soils. The passive resistance of natural soils or properly compacted fill soils can be assumed to be equal to the pressure developed by a fluid with a density of 300 pounds per cubic foot. A one-third increase in the passive value can be used for wind or seismic loads. The frictional resistance and the passive resistance of the soils can be combined without reduction in determining the total lateral resistance. 6.2 SITE COEFFICIENT AND SEISMIC ZONATION The site coefficient, S, can be determined as established in the Earthquake Regulations under Section 1628 of the Uniform Building Code, 1994 edition, for seismic design of the proposed building. Based on a review of the local soil and geologic conditions, the site can be classified as Soil Profile S2, and the site coefficient (S) can be taken as equal to a value of 1.2, as specified in the code. The site is located within UBC Seismic Zone 4. 6.3 EXCAVATION AND SLOPES Excavation of about 15 feet deep will be required for the basement level. Where the necessary space is available, temporary unsurcharged embankments may be sloped back at 1: 1 without shoring. Where space is not available, shoring will be required. Data for design of shoring are presented in a following section. The excavations should be observed by personnel of our firm so that any necessary modifications based on variations in the soil conditions encountered can be made. All applicable safety requirements and regulations, including OSHA regulations, should be met. 7 Grifin Realry SA, inc.-Geotechnical Investigation tizw/Crandall Project 70131-7-0261.0001 July 8. 1997 Where sloped embankments are used, the tops of the slopes should be barricaded to prevent vehicles and storage loads within 5 feet of the tops of the slopes. A greater setback may be necessary when considering heavy vehicles, such as concrete trucks and cranes; we should be advised of such heavy vehicle loadings so that specific setback requirements can be established. If the temporary construction embankments are to be maintained during the rainy season, berms are suggested along the tops of the slopes where necessary to prevent runoff water from entering the excavation and eroding the slope faces. The soils exposed in the cut slopes should be inspected during excavation by our personnel so that modifications of the slopes can be made i f variations in the soil conditions occur or if adverse water seepage conditions are developed. 6.4 SHORING General Where there is not sufficient space for sloped embankments, shoring will be required. One method of shoring would consist of cantilevered steel soldier piles placed in drilled holes and backfilled with concrete. The soldier piles can also be retained with drilled-in earth anchors or raker bracing. Caving and raveling of the granular soils should be considered during installation of the soldier piles. Special techniques and measures may be necessary in some areas to permit the proper installation of the soldier piles. The following information on the design and installation of the shoring is as complete as possible at this time. We can furnish additional required data as the design progresses. Also, we suggest that our firm review the final shoring plans and specifications prior to bidding or negotiating with a shoring contractor. Lateral Pressures For design of cantilevered shoring, a triangular distribution of lateral earth pressure may be used. It may be assumed that the retained soils with a level surface behind the cantilevered shoring will exert a lateral pressure equal to that developed by a fluid with a density of 30 pounds per cubic foot. 8 Gri#in Realty SA, inc.-Geotechnical Investigation Iiiw/Crandall Project 70131-7-0261.0001 July 8, 1997 For the design of tied-back or braced shoring, we recommend the use of a trapezoidal distribution of earth pressure. The recommended pressure distribution, for the case where the grade is level behind the shoring, is illustrated in the following diagram with the maximum pressure equal to 22H in pounds per square foot, where H is the height of the shoring in feet. (Where a combination of sloped embankment and shoring is used, the pressure would be greater and must be determined for each combination.) u )..i//2 //03 //02 4 //r 0.2H O . CO 0 M-HEIGHT OF 0 0.6H SHORING IN FT. 0 0 0 0 0. 1H 0 //A.//A'//Â£//90//A'//,0//A \|e- 22H -5,| (P.S.F.) In addition to the recommended earth pressure, the upper 10 feet of shoring adjacent to any vehicular traffic areas should be designed to resist a uniform lateral pressure of 100 pounds per square foot, acting as a result of an assumed 300 pounds per square foot surcharge behind the shoring due to vehicular traffic. If the traffic is kept back at least 10 feet from the shoring, the traffic surcharge may be neglected. Design of Soldier Piles For the design of soldier piles spaced at least two diameters on centers, the allowable lateral bearing value (passive value) of the soils below the level of excavation may be assumed to be 500 pounds per square foot per foot of depth, up to a maximum of 2,000 pounds per square foot. To develop the full lateral value, provisions should be taken to assure firm contact between the soldier piles and the undisturbed soils. The concrete placed in the soldier pile excavations may be a lean- mix concrete. However, the concrete used in that portion of the soldier pile which is below the 9 Grifin Realty SA, Inc.-Geotechnical Investigation Uiw/Crandall Project 70131-7-0261.0001 July 8. 1997 planned excavated level should be of sufficient strength to adequately transfer the imposed loads to the surrounding soils. The frictional resistance between the soldier piles and the retained earth may be used in resisting the downward component of the anchor load. The coefficient of friction between the soldier piles and the retained earth may be taken as 0.4. (This value is based on the assumption that uniform full bearing will be developed between the steel soldier beam and the lean-mix concrete and between the lean-mix concrete and the retained earth.) In addition, provided that the portion of the soldier piles below the excavated level is backfilled with structural concrete, the soldier piles below the excavated level may be used to resist downward loads. The frictional resistance between the concrete soldier piles and the soils below the excavated level may be taken as equal to 400 pounds per square foot. Lagging Continuous lagging will be required between the soldier piles. The soldier piles and anchors should be designed for the full anticipated lateral pressure. However, the pressure on the lagging will be less due to arching in the soils. We recommend that the lagging be designed for the recommended earth pressure but limited to a maximum value of 400 pounds per square foot. Anchor Design Tie-back friction anchors may be used to resist lateral loads. For design purposes, it may be assumed that the active wedge adjacent to the shoring is defined by a plane drawn at 35 degrees from the vertical through the bottom of the excavation. The anchors should extend at least 15 feet beyond the potential active wedge and to a greater length if necessary to develop the desired capacities. The capacities of anchors should be determined by testing of the initial anchors as outlined in a following section. For design purposes, it may be estimated that drilled friction anchors will develop an average friction value of 600 pounds per square foot. Only the frictional resistance developed beyond the active wedge would be effective in resisting lateral loads. If the anchors are 10 Grifin Realty SA, Inc.-Georechnical Investigation L,aw/Crandall Project 70131-7-0261.0001 July 8, 1997 spaced at least 6 feet on centers, no reduction in the capacity of the anchors need be considered due to group action. Anchor Installation The anchors may be installed at angles of 15 to 40 degrees below the horizontal. Caving of the anchor holes should be anticipated and provisions made to minimize such caving. The anchors should be filled with concrete placed by pumping from the tip out, and the concrete should extend from the tip of the anchor to the active wedge. To minimize chances of caving, we suggest that the portion of the anchor shaft within the active wedge be backfilled with sand before testing the anchor. This portion of the shaft should be filled tightly and flush with the face of the excavation. The sand backfill may contain a small amount of cement to allow the sand to be placed by pumping. Anchor Testing Our representative should select at least one of the initial anchors for a 24-hour 200% test, and two additional anchors for quick 200% tests. The purpose of the 200% tests is to verify the friction value assumed in design. The anchors should be tested to develop twice the assumed friction value. Anchor rods of sufficient strength should be installed in these anchors to support 200% test loading. Where satisfactory tests are not achieved on the initial anchors, the anchor diameter and/or length should be increased until satisfactory test results are obtained. The total defiection during the 24-hour 200% tests should not exceed 12 inches during loading; the anchor deflection should not exceed 0.75 inch during the 24-hour period, measured after the 200% test load is applied. If the anchor movement after the 200% load has been applied for 12 hours is less than 0.5 inch, and the movement over the previous 4 hours has been less than 0.1 inch, the test mav be terminated. Ill----Ill=/ 11 Griffin Really SA, Inc.-Geotechnical Investigation I.aw/Crandall Project 70131-7-0261.0001 July 8, 1997 For the quick 200% tests, the 200% test load should be maintained for 30 minutes. The total deflection of the anchor during the 200% quick test should not exceed 12 inches; the deflection after the 200% test load has been applied should not exceed 0.25 inch during the 30-minute period. All of the production anchors should be pretested to at least 150% of the design load; the total deflection during the tests should not exceed 12 inches. The rate of creep under the 150% test should not exceed 0.1 inch over a 15-minute period for the anchor to be approved for the design loading. After a satisfactory test, each production anchor should be locked-off at the design load. The locked-off load should be verified by rechecking the load in the anchor. If the locked-off load varies by more than 10% from the design load, the load should be reset until the anchor is locked- off within 10% of the design load. The installation of the anchors and the testing of the completed anchors should be observed by our firm. Internal Bracing Raker bracing, if used, could be supported laterally by temporary concrete footings (deadmen). For design of such temporary footings, poured with the bearing surface normal to rakers inclined at 45 to 60 degrees with the vertical, a bearing value of 2,000 pounds per square foot may be used Â· at the excavation level, provided the shallowest point of the footing is at least 1 foot below the lowest adjacent grade. To reduce the movement of the shoring, the rakers should be preloaded or at least tightly wedged between the footings and the soldier piles. Dellection It is difficult to accurately predict the amount of deflection of a shored embankment. It should be realized, however, that some dellection will occur. We estimate that this deflection would be less than 1 inch at the top of a cantilevered shoring system, and less than M inch for a braced shoring system. If greater dellection occurs during construction, additional bracing may be necessary to 12 Grifin Realty SA, Inc.-Geotechnical Investigation Unv/Crandall Project 70131-7-0261.0001 July 8, 1997 minimize settlement of the adjacent structures. If desired to reduce the deflection of the shoring, a greater active pressure could be used in the shoring design. Monitoring Some means of monitoring the performance of the shoring system is recommended. The monitoring should consist of periodic surveying of the lateral and vertical locations of the tops of all the soldier piles and the lateral movement along the entire lengths of selected soldier piles. Also, some means of periodically checking the load on selected anchors may be necessary. We will be pleased to discuss this further with the other design consultants and the contractor when the design ofthe shoring system has been finalized. 6.5 WALLS BELOW GRADE Lateral Pressures For design of cantilevered retaining walls below grade where the surface of the backfill is level, it may be assumed that the soils will exert a lateral pressure equal to that developed by a fluid with a density of 30 pounds per cubic foot. The building walls below grade should be designed to resist a trapezoidal distribution of lateral earth pressure plus surcharges from adjacent loads. The lateral earth pressure on the permanent walls below grade will be the same as that recommended for design of temporary shoring with a maximum lateral pressure will be 22H in pounds per square foot, where H is the height of the wall in feet. In addition to the recommended earth pressure, the upper 10 feet of walls adjacent to any vehicular traffic areas should be designed to resist a uniform lateral pressure of 100 pounds per square foot, acting as a result of an assumed 300 pounds per square foot surcharge behind the walls due to normal traffic. If the traffic is kept back at least 10 feet from the walls, the traffic surcharge may be neglected. 13 Gri#in Realry SA, Inc.-Geotechnical investigation Law/Crandall Project 70131-7-0261.0001 July 8, 1997 Backfill Any required soil backfill should be mechanically compacted, in layers not more than 8 inches in thickness. to at least 90% of the maximum dry density obtainable by the ASTM Designation Dl 557-91 method of compaction. The on-site soils may be used in the backfill. Flooding should not be permitted. Proper compaction of backfill will be necessary to reduce settlement of the backfill and to reduce settlement of overlying walks and paving. Some settlement of the backfill should be anticipated, and any utilities supported therein should be designed to accept differential settlement, particularly at the points of entry to the building. Also, provisions should be made for some settlement of concrete walks on grade supported on backfill. Drainage Walls below grade and retaining walls should be designed to resist hydrostatic pressures or be provided with drain pipes or weepholes. A drain pipe could consist of a 4-inch-diameter perforated pipe placed with perforations down at the base of the wall. The pipe should be sloped at least 2 inches in 100 feet and surrounded by filter gravel. The filter gravel should meet the requirements of Class 2 Permeable Material as defined in the current State of California, Department of Transportation, Standard Specifications. If Class 2 Permeable Material is not available, 4-inch crushed rock or gravel separated from the on-site soils by an appropriate filter fabric, such as Mirafi 140 or equivalent, can be used. The crushed rock or gravel should have less than 5% passing a No. 200 sieve. For exterior retaining walls, drainage can be provided by weepholes placed about 10 feet on center. 6.6 FLOOR SLAB SUPPORT If the subgrade is prepared as recommended in the following section on grading, the building floor slab can be supported on grade. Construction activities and exposure to the environment can cause deterioration of the prepared subgrade. Therefore, we recommend that our field representative observe the condition of the final subgrade soils immediately prior to slab-on-grade construction, and, if necessary, perform further density and moisture content tests to determine the suitability of the final prepared subgrade. 14 Griffin Realty SA. Inc.-Geotechnical Investigation Law/Crandall Project 70131-7-0261.0001 July 8, 1997 I f vinyl or other moisture-sensitive floor covering is planned, we recommend that the floor slab in those areas be underlain by a capillary break consisting of a vapor-retarding membrane over a 4-inch-thick layer of gravel. Two-inch-thick layers of sand should be placed above and below the membrane to decrease the possibility of damage to the membrane and reduce slab curling. We suggest the following gradation for the gravel: Sieve Size Percent Passing %4"90-100 No. 4 0-10 No. 100 0-3 A low-slump concrete should also be used to minimize possible curling of the slab. Care should be taken during the placement of the concrete to prevent displacement of the sand. The concrete slab should be allowed to cure properly before placing vinyl or other moisture-sensitive floor covering. 6.7 PAVING An R-value of 20 was assumed for design of asphalt paving based on our observations and experience with similar soil conditions. The R-value should be confirmed during grading. Assuming that the paving subgrade will consist of the on-site or comparable soils compacted to at least 90% as recommended in the following section on grading, the minimum recommended paving thicknesses are presented in the following tables. The asphalt paving sections were determined using the flexible pavement design procedure used by the Orange County Environmental Management Agency. The Portland Cement Concrete (PCC) paving sections were determined using the Portland Cement Association design method; base course beneath the PCC paving is not required. 15 Griffin Really SA, Inc.-Geotechnical Investigation Law/Crandall Project 70131-7-0261.0001 July 8, 1997 Asphalt Concrete Paving Asphalt Concrete Base Course Traffic Use Traffic Index (inches)(inches) Automobile Parking 4.0 3 4 Drives Subject to 5.5 3 10 Light Truck Traffic Drives Subject to 7.0 4 13 Heavy Truck Traffic Portland Cement Concrete Paving Portland Cement Traffic Use Traffic Index Concrete (inches) Automobile Parking 4.0 7 Drives Subject to 5.5 7% Light Truck Traffic Drives Subject to 7.0 8 Heavy Truck Traffic We can determine the recommended paving and base course thicknesses for other Traffic Indices if required. Careful inspection is recommended to verify that the recommended thicknesses or greater are achieved, and that proper construction procedures are followed. The base course should conform to requirements of Section 26 of State of California Department of Transportation Standard Specifications (Caltrans), latest edition, or meet the specifications for untreated base as defined in Section 200-2 of the latest edition of the Standard Specifications for Public Works Construction (Green Book). The base course should be compacted to at least 95%. 6.8 GRADING The existing fill soils were not observed and tested during placement and are not considered suitable for support of foundations, paving, or slabs on grade. The existing fill soils should be excavated and replaced as properly compacted fill. All required fill should be uniformly well compacted and observed and tested during placement. The on-site soils can be used in any required fill. If a basement is not planned. the existing basement should be backfilied. However. 16 Griffin Realty SA. Inc.-Geotechnical Investigation Law/Crandall Project 70131-7-0261.0001 July 8.1997 prior to backfilling, holes 2 to 3 inches in diameter and spaced at 10 feet on centers should be cored through the floor slab of the existing basement. Site Preparation After the site is cleared and existing fill soils are excavated as recommended, the exposed natural soils should be carefully observed for the removal of all unsuitable deposits. Next, the exposed soils should be rolled with heavg compaction equipment. At least the upper 6 inches of the exposed soils should be compacted to at least 90% of the maximum dry density obtainable by the ASTM Designation D 1557-91 method of compaction. Compaction Any required fill should be placed in loose lifts not more than 8 inches thick and compacted. The fill should be compacted to at least 90% of the maximum density obtainable by the ASTM Designation D1557-91 method of compaction. The moisture content of the on-site soils at the time of compaction should vary no more than 2% below or above optimum moisture content. Material for Fill The on-site soils, less any debris or organic matter, can be used in required fills. Cobbles larger than 4 inches in diameter should not be used in the fill. Any required import material should consist of relatively non-expansive soils with an expansion index of less than 35. The imported materials should contain sufficient fines (binder material) so as to be relatively impermeable and result in a stable subgrade when compacted. All proposed import materials should be approved by our personnel prior to being placed at the site. 6.9 GEOTECHNICAL OBSERVATION The reworking of the upper soils and the compaction of all required fill should be observed and tested during placement by a representative of our firm. This representative should perform at least the following duties: 17 Griffin Really SA. Inc.-Geotechnical Investigation Law/Crandall Project 70131-7-0261.0001 July 8. 1997 â€¢ Observe the clearing and grubbing operations for proper removal of all unsuitable materials. â€¢ Observe the exposed subgrade in areas to receive fill and in areas where excavation has resulted in the desired finished subgrade. The representative should also observe proofrolling and delineation of areas requiring overexcavation. â€¢ Evaluate the suitability of on-site and import soils for fill placement; collect and submit soil samples for required or recommended laboratory testing where necessary. â€¢ Observe the fill and backfill for uniformity during placement. â€¢ Test backfill for field density and compaction to determine the percentage of compaction achieved during backfill placement. â€¢ Observe the drilling and pouring of the piles to verify that the desired diameter and depth are obtained. â€¢ Observe and probe foundation materials to confirm that suitable bearing materials are present at the design foundation depths. The governmental agencies having jurisdiction over the project should be notified prior to commencement of grading so that the necessary grading permits can be obtained and arrangements can be made for required inspection(s). The contractor should be familiar with the inspection requirements ofthe reviewing agencies. 7.0 BASIS FOR RECOMMENDATIONS The recommendations provided in this report are based upon our understanding of the described project in formation and on our interpretation of the data collected during our current and previous subsurface explorations. We have made our recommendations based upon experience with similar subsurface conditions under similar loading conditions. The recommendations apply to the specific project discussed in this report; therefore, any change in the structure configuration, loads, location, or the site grades should be provided to us so that we can review our conclusions and recommendations and make any necessary modifications. 18 Grillin Really SA, Inc.-Geotechnical Investigation Law/Crandall Project 70131-7-0261.0001 July 8, 1997 The recommendations provided in this report are also based upon the assumption that the necessary geotechnical observations and testing during construction will be performed by representatives of our firm. The field observation services are considered a continuation of the geotechnical investigation and essential to verify that the actual soil conditions are as expected. This also provides for the procedure whereby the client can be advised of unexpected or changed conditions that would require modifications of our original recommendations. In addition, the presence of our representative at the site provides the client with an independent professional opinion regarding the geotechnically related construction procedures. If another firm is retained for the geotechnical observation services, our professional responsibility and liability would be limited to the extent that we would not be the geotechnical engineer of record. 19 1 1 1 1 1 1 1 1 FIGURES 1 1 1 1 1 1 1 1 1 EXISTING EXISTING ANNEX SUBTERRANEAN BLDG.PARKING (TO REMAIN)(TO REMAIN) , 1 T----, / 2 1 EXISTING BLDG. 1 [TO BE DEMOLISHED)lg/ 1 El 1 \ .0- '- k 1 1 1 1 1 1 2 ili 'A .0 1-1101 1 l 11 < m I 1 -I--TO SANTA ANA BLVD. 1 1 TO CIVIC CTR. DR. 1 1 1 1 ROSS ST. B.M FOR BOR. ELEVS CHISELED W IN SIDEWALK ASSUMED EL .100.00 MEI: 2 CURRENT INVESTIGATION (70131-7-0261.0001) 1 Q PREVIOUS INVESTIGATION (58338) - BORING LOCATION AND NUMBER SITE PLAN SCALE 1 = 40' LAW/CRANDALL , FIGURE 1 JOB 7013/-7-0241. 000< DATE F -25- 47 F.T. DR. rlÂ·A. O.E. CHKD W 0 0 ALLOWABLE DOWNWARD PILE CAPACITY in Kips 40 80 120 160 200 240 /-- Pile Diameter in Inches 0 (18 267*2 \\ 1-00 1Â·U - - 0 20 40 60 80 100 120 ALLOWABLE UPWARD PILE CAPACITY in Kips NOTES: (1) The indicated Mlues refer to the total of dead plus INe loads; a one-third increase may be used when considering wind or seismic loads. (2) Piles in groups should be spaced a minimum of 2-1/2 diameters on centers, and should be drilled and filled alternately with the concrete permitted to set at least 8 hours before drilling an adjacent hole. (3) The indicated Malues are based on the strength of the soils; the actual pile capacities may be limited to lesser yalues by the strength of the piles. DRILLED PILE CAPACITIES LAW/CRANDALL n FIGURE 2 JOB 70131.70261.0001 DATE : 6/26/97 OE. mwh CHKD:PENETRATION BELOW PILE CAP in Feet 1 1 1 1 1 1 1 1 APPENDIX A EXPLORATIONS AND LABORATORY TESTS 1 1 1 1 1 1 1 1 1 Gri#in Really SA. Inc.-Geotechnical Investigation Law/Crandall Project 70131-7-0261.0001 July 7,1997 APPENDIX A EXPLORATIONS AND LABORATORY TESTS EXPLORATIONS The soil conditions beneath the site were recently explored by drilling two borings. In addition, data were available from our prior investigation at the site (our Job No. 58338). The locations of our current and prior borings are shown in Figure 1. The current borings were drilled to depths of 68% and 70 feet below the existing grade using 18-inch-diameter bucket-type drilling equipment. Caving and raveling of the boring walls occurred as indicated on the boring logs; however, easing or drilling mud was not used to extend the borings to the depths drilled. The soils encountered were logged by our field technician, and undisturbed and bulk samples were obtained for laboratory inspection and testing. The logs of the current borings are presented in Figures A-1.1 through A-1.2; the logs from prior borings are presented in Figures A-1.3 and A- 1.5. The depths at which the undisturbed samples were obtained are indicated to the left of the boring logs. The number of blows required to drive the Crandall sampler 12 inches is indicated on the logs. The soils are classified in accordance with the Unified Soil Classification System described in Figure A-2. LABORATORY TESTS Laboratory tests were performed on selected samples obtained from the borings to aid in the classification of the soils and to determine their engineering properties. The field moisture content and dry density of the soils encountered were determined by performing tests on the undisturbed samples. The results of the tests are shown to the left of the boring logs. A-1 Griffin Realry SA, Inc.-Geotechnical Investigation Inw/Crandall Project 70131-7-0261.0001 July 7,1997 Direct shear tests were performed on selected undisturbed samples to determine the strength of the soils. The tests were performed at field moisture content and after soaking to near-saturated moisture content and at various surcharge pressures. The yield-point values determined from the direct shear tests are presented in Figure A-3, Direct Shear Test Data. Confined consolidation tests were performed on two undisturbed samples to determine the compressibility of the soils. Water was added to one of the samples during the tests to illustrate the effect of moisture on the compressibility. The results of the tests are presented in Figures A-4, Consolidation Test Data. The optimum moisture content and maximum dry density of the upper soils were determined by performing a compaction test on a sample obtained from Boring 1. The test was performed in accordance with the ASTM Designation D1557-91 method of compaction. The results of the tests are presented in Figure A-5, Compaction Test Data. In addition to the normal consolidation tests, a "quick" consolidation test was performed on an undisturbed sample to determine the hydroconsolidation potential of the soils. The test was performed by confining the sample under a normal surcharge pressure, allowing the sample to consolidate at its field moisture content, and then saturating the sample and measuring the consolidation resulting from the addition of water. The results (percent hydroconsolidation) of the test are presented in Figure A-6, Hydroconsolidation Test Data. 4 A-2 EB D>EVATION Hld3a BORING 1 LU DATE DRILLED:June 5,1997 EQUIPMENT USED: 18" - Diameter Bucket ELEVATION:100.6 ./ 100 - 4 SM 2.8 102 2 . IE Ili 3" Asphalt Paving FILL - SILTY SAND - fine, pieces of concrete and metal, light brown SURFACE OF NATURAL SOIL SILTY SAND - fine, brown 5 t' lit 95 - - 10 90 - 1(KiÂ· sp-SAND and SILTY SAND - fine, light brown 3.0 99 3 'intil SM Wn 1.0 95 2 .OV; 1 ML SANDY SILT - some Clay, few Gravel, brown 10.3 102 2 1 - 15 85 -7.0 105 2 1 CLAYEY SILT - some Sand, brownML 17.9 108 3 1 - 20 80 - 7.4 111 2 1 Layers of Sandy Silt - 25 20.2 101 2 1 ML SANDY SILT - some Clay, light greyish brown 75 - 15.8 109 9 1 Brown * Number of blows required to drive the Crandall sampler 12 inches for depths of: - 30 0' to 25' using a 1600 pound hammer falling 12 inches; 70 -10.7 111 10 1 25' to 50' using an 800 pound hammer falling 12 inches; Below 50' using a 1200 pound hammer falling 12 inches. * * Elevations refer to assumed datum; see Figure 1 for location and elevation of bench mark. 12.3 97 11- 35 65 -Layer of fine Sand, brown 10.740 J013 Not 118 5 1 Few Gravel, brown (CONTINUED ON FOLLOWING FIGURE) LOG OF BORING LAW/CRANDALL FIGURE A-1.la e: The log of subsurface conditions shown hereon applies only at the specific boring location and at the date indicated 11 is not warranted to be representative of subsurface conditions at other locations and times. I D>ATION llSN3 2 2= - D= 5 0: O 09 ELEV 30 BORING 1 (Continued) DATE DRILLED:June 5, 1997 EQUIPMENT USED: 18" - Diameter Bucket ELEVATION:100.6 ** 60 - 45 SAND - fine, some Gravel, few Cobbles (to 5" in size), lightD ..brown22: i 20 t.ip: ML SANDY SILT - brown 50 20.5 108 6 1 ML CLAYEY SILT - brown 55 16.1 116 4 1 Layer of Sandy Silt 19.3 114 11 /-,7,-----60 .N : SM SILTY SAND - fine to medium, about 20% Gravel, brown R bt A :.13 Sw SAND - well graded, light brown 2.9 114 14 1 2Â·Â·.3 -65 :d '. ML CLAYEY SILT - some Sand, brown 70 24.5 101 17 1 (BORING TERMINATED AT A DEPTH OF 70' DUE TO LACK OF PROGRESS) NOTE: Water level measured at a depth of 65 !4' 15 minutes after completion of drilling. Caving from 6' to 10' (to 3' in diameter) and below 6614' LOG OF BORING LAW/CRANDALL FIGURE A-l.lb I JCIO 131_I DI/25 GIV M-C 'Note: The log of subsurface conditions shown hereon applies only at the specific boring location and at the date indicated.It is not wairanted to be representative of subsurface conditions at other locations and times.W Ull 0 u'l 1 1 50 - 55 - D>EVATION Hld30 UJ to 0 - Z =i U.1 0 Oh Z- 3 45 O -Di 0 23 BORING 2 DATE DRILLED:June 10,1997 EQUIPMENT USED: 18" - Diameter Bucket ELEVATION:103.1 @li 100 - 8.1 129 12 3" Asphalt Paving - 7" Base Course :, SM FILL - SILTY SAND - fine, some pieces of brick and metal, light brown SURFACE OF NATURAL SOIL ML SANDY SILT - some Clay, few roots, brown -5 2 2 2 SM SILTY SAND - fine, brown 2.1 102 2 1 95 - 4.5 103 2 Light brown- 10 ... ML SANDY SILT - few roots, light brown 9.9 93 2 1 Rootlets 90 - 15 9.9 110 3 1 Brown 85 - 14.9 97 3 1 - 20 12.5 105 4 1 Rootlets 80 - - 25 14.9 110 3 1 12.5 98 9 1 75 - - 30 13.4 106 8 1 Some Clay 70 - - 35 10.2 102 8 1 65 - 40 Some Clay 18.6 104 12 i.-:-- (CONTINUED ON FOLLOWING FIGURE) LOG OF BORING LAW/CRANDALL FIGURE A-1.2a 11111 11111 J(11111 013 /////61 ///// DA16/25 GIVII DR M CI Note: The log of subsurface conditions shown hereon applies only at the specific boring location and at the date indicated.It is not warranted to be representative of subsurface conditions at other locations and times. 0 2% L. g- E- 22 z. ELEV 5 2 9 BORING 2 (Continued) 0: w 0% rl 9 2 * DATE DRILLED:June 10,1997 O 2 4 EQUIPMENT USED: 18" -Diameter Bucket @ in ELEVATION:103.1 60 - Layer of Silty Sand SP SAND - fine, light brown Layer of Sandy Silt 1.5 119 17 1%41 A. Few Cobbles (to 8" in size) 1.9 118 15 Fine to coarse, light brown ML CLAYEY SILT - brown 20.7 106 3 I 18.8 113 5 1 SANDY SILT - some Clay, brownML 26.1 101 11 1 Layer of Silty Sand SW SAND - well graded, about 20% Gravel and Cobbles, light greyish brovvn END OF BORING AT 68 M' NOTE: Water seepage encountered at 67 72'. Water level measured at a depth of 67 h' 30 minutes after completion of drilling. Heavy caving and raveling from 47' to 51' and from 67!4' to 68/2' (to 3' in diameter). LOG OF BORING LAW/CRANDALL FIGURE A-1.2b --J â‚¬01361 DA6/25 GA/ DR. . M Cl Note: The log of subsurface conditions shown hereon applies only at the specific boring location and at the date indicated.It is not warranted to be representative of subsurface conditions at other locations and times.CO Ul N U1 0 Ul 0 1 1 1 1 99 - 09 - - 55 - 50 55 - - 45 11.-L- 16 "-Diameter Ro* Buckit Hole Drilled October 1, 1958 0 Elevatian 102.4* 100-5.1*- 911. in SILTY 8AND - sant predaninantly fine, contains large amount of ailt, brown . 6.4%. 86 :f f f Sand fine to very fine, medium amount of silt, light brown 11.0*- 9413; f Sand predaminantly very fine, containâ€¢ 10 large amount of Bilt 90- 15Â·00- 95 1 14 - 10-106 i N . â€¢20 80- - 25.80- 96 1 Grading to SILT - containg small amount of very fine sand, brown Small amount of clay SILTY SAND - sand predominantly very fine, contains large amount of Bilt, brorn SILT - contains large amount of clay, plastic, brown 4 30 -7 SILTY SAND - and predaninantly fine, contains 12.00-104 1-large amount of silt, brown e Al 0 40 060_ O -4 )4 5o 50 _ % -70_ - 34.6%- 84.Layers of ELASTIC SILT and SILT 5.7%-118 i 22.4%-104 1 7, 20.7%-107 1 POORLY GRADED SAND - fine to medium, trace of fines, feâ€¢ gravel, brown Large amount of gravel, few cobbles to 6" Grading to WELL GRADED SAND - contains large amount of gravel and small cobbles, trace of fines, brain SILT - cantaine large amount of clay, slightly plastic, small amount of very fine Band, fe, amall cobbles, brown 21.5%-101 1 60 15.90-112 '*d pÂ°Â°=Dg=El; =to medium, large 40-0171 WELL GRADED SAND - contains large eount of j..,9.1 gravel and cobbles to 10", greyiah-brown NOTE: Groundwater not encountered; caved badly fram 42' to 46' and fram 60' to 65'. 15 9%-lf 'Indicates depth at which undisturbed simple obtained Dry density in pounds per cubic foot Field moisture cantent in percent af dry weight Soils classified in accordance vith the Unified Soil Classificatian System. * 11*vatians refer to assumed datum (see Plot Plan for benchmark). LEROY CRANDALL O ASSOCIATES FIGURE A-1.3 JUU 1,Al t 8 Y Â£ <54 ... 4 - Ca-+ LOG OF BORING 1 LOO OF BORING 2 24"-Diameter Rotary Bucket Hole Drilled October 2, 1958 Elevation 102.00 100-0 f : SILTY SAND - aand predominantly fine, contains 3.40- 95/62 j i large amount of silt, brown Small amount of silt .. 21.4%- 81 10 SILT - cantains small amount of clay and very fine sand, brown 90-22.2%- 98 6.6%-10(*UJ SILTY SAND - sand uredominantly fine, containst.1-medium amount of silt, brown 20 24 Layer of FINE SAND 80- Â®64 25. 70- 90:fi 2#Ir-0709*lps115'e amolmt of clay, brown 18.0%-101 Small amount of olay and medium amount of very fine sand 3o 70 _ 60- ,EZ Layers of POORLY GRADED FINE SAND1 6 8.2%-11lliE SILTY SAND and POORLY GRADED FINE SAND ' 40 frht 05.Â·i: WELL GRADED SAND - containa large amount of 3.2%-1(7:itbi gravel, few small cobbles, trace of silt, broln SILT - contains large amount af clay and 22.6%-1031 small amount of very fine sand, brown 5o 50_ 17.9%-1111 6o 40- .0.Small amouu b of gravel and cobbles21. 3%-1031 77 SILTY SAND - sand predominantly fine to very 1, : t.fine, contains large amount of silt 54-' WELL GRADED RAND - cantaing large amount of gravel and small cobbles, greyish-broin NOTE: Groundiater not encountered 40, to 44, and 60' to 63'Â· ; caving from LEROY CRANDALL 6- ASSOCIATES FIGURE A-1.4 JUD. --- .--- I. UAIt 8 7 C. Â« 6 . Elevation in feet LOG OF BORING 3 24"-Diameter Rot/ry Bucket Hole Drilled October 1, 1958 100- Elevatian 101.1 C Â·: SILTY SAND - sand predominantly fine, contains 6.7%- 931{ Â·:large amount of silt, brown ... 11. 1444 Layer of po0RLY GRADED FINE. SAND 90 10 RE Layer of SILT 5. 3%-102!j. f j Medium amount of silt F . Small amount of gravel SILT - contains medium amount of clay and 19.4%-1031 very fine sand, broin E Layer of POORLY GRADED SAND - fine to 4 20 medium, with gravel80 - 26.0%- 891 o Slightly plastic 21.9%-1011 70 - 60 - Â¤ 30 0. 40 A. 7. 3%-114+:-,-cm 2 9:0, '3:10 g 3.2*-1001 :4 P. 22.5%-1031 Layer of POORLY GRADED SAND - fine to medium with gravel Lens of FINE SAND POORLY GRADED SAND - fine, contains few gravel and small cobbles, small amount of fines, broâ€¢n Sand fine to medium, medium to large amountof gravel and small cobbles SILT - contains large amount of clay, brown 50 Few small gravel50 _14.0%-1081 40 - ..7.9- \ELL GRADED SAND - contains large amount ofgravel, medium amount of cobbles to 8", 3.60-1151 *W trace of fines, broâ€¢n 60 bif NOTE: Groundwater not encountered; oeving fram 18' to 20'; 38' to 45' and 53' to 60'. LEROY CRANDALL 6- ASSOCIATES cint *c 8-14 Elevation in feet SHEAR STRENGTH in Pounds per Square Foot 0 0 0 2@6 \ 2000 000 2000 3000 /1@12 02@16 01@2, *1@3 0 1@34 2@6 1 4000 5000 6000 O.1@3 1000 \ BORING NUMBER & SAMPLE DEPTH (FT.) 02@21 3000 0 222 ju 4000 82Â¢Z!39 02@54 VALUES USED / IN ANALYSES 5000 01@54 6000 - '0,@64 KEY 0 Samples tested at field moisture content 2 Samples tested after soaking to a moisture contentnear saturation 4-Natural solls DIRECT SHEAR TEST DATA LAW/CRANDALL L. FIGURE A-3 I JOI'- 131 1 00 DA/18/ R WKD SURCHARGE PRESSURE in Pounds per Square Foot LOAD IN KIPS PER SQUARE FOOT 0.4 0 0.5 0.6 0.7 0.8 0.91.0 2.0 3.0 4.0 5.0 6.0 7.0 1 1 Boring 2 at 12' /-- SANDY SILT 0.02 Boring 1 at 49' \ SANDY SILT -2- NOTE: Wateradded to sample from Boring 2 afterconsolidation under a load of 3.6 kips per sQuare foot The other sample tested at field moisture content. CONSOLIDATION TEST DATA LAW/CRANDALL 8.0 FIGURE A-4 JOB 70131.70261.0001 DATE 6/26/97 DR JB 0E MWH CHKD CONSOLIDATION IN INCHES PER INCH 0 0 0 0 0 0 0 0 (JO CD fL'O EL O BORING NUMBER AND SAMPLE DEPTH:1 at 2' to 5' SOIL TYPE:SILTY SAND MA)0MUM DRY DENSITY:126 (lbs./cu. ft.) OPTIMUM MOISTURE CONTENT:9.5 (% of dry wt.) TEST METHOD:ASTM Designation D1557-91 COMPACTION TEST DATA LAW/CRANDALL FIGURE A - JOB--70131.70261.0001 |r23/9 0 DAT JB MWA-- CHKD Ul BORING NUMBER AND SAMPLE DEPTH:1 at 12' SOIL TYPE:SANDY SILT SURCHARGE PRESSURE:3600 (lbs./sq. ft.) PERCENT HYDROCONSOLIDATION:3.8 HYDROCONSOLIDATION TEST DATA LAW/CRANDALL FIGURE A ./ /1:'I 702/9'BFO 1 E : |3/97 MW C CD 1 1 1 1 1 1 1 1 APPENDIX B 1 SOIL CORROSIVITY STUDY BY M.J. SCH[FF AND ASSOCIATES 1 1 1 1 1 1 M. J. SCHIFF & ASSOCIATES, INC. Consulting Corrosion Engineers - Since 1959 1291 North Indian Hill Boulevard Claremont, California 91711-3897 Phone 909-626-0967 FAX 909-621-1419 E-mail SCHIFFCORR@AOL.COM June 26,1997 LAW/CRANDALL, INC. 200 Citadel Drive Los Angeles, California 90040-1554 Attention:Mr. Michael Han Re:Soil Corrosivity Study Santa Ana Police Department Building Santa Ana, California Your #70131-7-0261.0001, MTS&A #97192 INTRODUCTION Laboratory tests have been completed on two soil samples we selected from your boring logs for the referenced police department project. The purpose of these tests was to determine if the soils may have deleterious effects on underground utilities, hydraulic elevator cylinders, and concrete foundations. We assume that the samples provided are representative of the most corrosive soils at the site. The scope of this study is limited to a determination of soil corrosivity and general corrosion control recommendations for materials likely to be used for construction. If the architects and/or engineers desire more specific information, designs, specifications, or review of design, we will be happy to work with them as a separate phase ofthis project. TEST PROCEDURES The electrical resistivity of each sample was measured in a soil box per ASTM G57 in its as- received condition and again after saturation with distilled water. Resistivities are at about their lowest value when the soil is saturated. The pH of the saturated samples was measured. A 5:1 water:soil extract from each sample was chemically analyzed for the major anions and cations. Test results are shown on Table 1. CORROSION AND CATHODIC PROTECTION ENGINEERING SERVICES PLANS AND SPECIFICATIONS â€¢ FAILURE ANALYSIS â€¢ EXPERT WITNESS ' CORROSIVITY AND DAMAGE ASSESSMENTS LAW/CRANDALL, INC.June 26,1997 MJS&A #97192 Page 2 SOIL CORROSIVITY A major factor in determining soil corrosivity is electrical resistivity. The electrical resistivity of a soil is a measure of its resistance to the flow of electrical current. Corrosion of buried metal is an electrochemical process in which the amount of metal loss due to corrosion is directly proportional to the flow of electrical current (DC) from the metal into the soil. Corrosion currents, following Ohm's Law, are inversely proportional to soil resistivity. Lower electrical resistivities result from higher moisture and chemical contents and indicate corrosive soil. A correlation between electrical resistivity and corrosivity toward ferrous metals is: Soil Resistivity in ohm-centimeters Corrosivity Category over 10,000 mildly corrosive 2,000 to 10,000 moderately corrosive 1,000 to 2,000 corrosive below 1,000 severely corrosive Other soil characteristics that may influence corrosivity towards metals are pH, chemical content, soil types, aeration, anaerobic conditions, and site drainage. Electrical resistivities were in mildly and moderately corrosive categories with as-received moisture. When saturated, both resistivities dropped into the moderately corrosive category. Soil pH values were 6.4 and 6.5. These values are slightly acidic and do not particularly increase soil corrosivity. The chemical content of the samples was low. Tests were not made for sulfide or negative oxidation-reduction (redox) potentials because they would not exist in these aerated samples. This soil is classified as moderately corrosive to ferrous metals. LAW/CRANDALL, INC.June 26,1997 MJS&A #97192 Page 3 CORROSION CONTROL The life of buried materials depends on thickness, strength, loads, construction details, soil moisture, etc., in addition to soil corrosivity, and is, therefore, difficult to predict. Of more practical value are corrosion control methods that will increase the life of materials that would be subject to significant corrosion. Steel Pipe Abrasive blast underground steel utilities and apply a high quality dielectric coating such asÂ· extruded polyethylene, a tape coating system, hot applied coal tar enamel, or fusion bonded epoxy. Bond underground steel pipe with rubber gasketed, mechanical, grooved end, or other nonconductive type joints for electrical continuity. Electrical continuity is necessary for corrosion monitoring and cathodic protection. Electrically insulate each buried steel pipeline from dissimilar metals, cement-mortar coated and concrete encased steel, and above ground steel pipe to prevent dissimilar metal corrosion cells and to facilitate the application of cathodic protection. With the above recommendations in place, we would not anticipate corrosion problems for at least 20 years and probably much longer. Further, cathodic protection can be easily applied in the future, if necessary. Hydraulic Elevator Coat hydraulic elevator cylinders as described above. Electrically insulate each cylinder from building metals by installing dielectric material between the piston platen and car, insulating the bolts, and installing an insulated joint in the oil line. Apply cathodic protection to hydraulic cylinders as per NACE International RP-0169-92. As an alternative to electrical insulation and cathodic protection, place each cylinder in a plastic easing with a plastic watertight seal at the bottom. The elevator oil line should be placed above ground if possible but, if underground, should be protected as described above for steel utilities. Iron Pipe Cast and ductile iron piping do not require special protective measures such as a plastic wrap. However. to avoid possibly creating corrosion problems, iron should not be placed partially in contact with concrete such as thrust blocks. Use coatings mentioned above for steel or 8 mil thick low-density polyethylene or 4 mil thick high-density polyethylene plastic sheets per AWWA C105 to prevent such contact. Electrically insulate underground iron pipe from dissimilar metals and above ground iron pipe with insulated joints. LAW/CRANDALL, INC.June 26,1997 MJS&A #97192 Page 4 Copper Tube No special precautions are necessary for bare copper tubing for cold water. Hot water tubing may be subject to a higher corrosion rate. The best corrosion control measure would be to place the hot copper tubing above ground. If buried, encase in plastic pipe to prevent soil contact or apply cathodic protection. Plastic and Vitrified Clay Pipe No special precautions are required for plastic and vitrified clay piping placed underground from a corrosion viewpoint. Protect any iron valves and fittings with a double polyethylene wrap per AWWA C105 or as described below for bare steel appurtenances. Where concrete thrust blocks are to be placed against iron, use a single polyethylene wrap to prevent concrete/iron contact and to eliminate the slipperiness of a double wrap. All Pipe On all pipe, coat bare steel appurtenances such as bolts, joint harnesses, or Dexible couplings with a coal tar or elastomer based marnie, coal tar epoxy, moldable sealant wax tape, or equivalent after assembly. Where metallic pipelines penetrate concrete structures such as building floors or walls, use plastic sleeves, rubber seals, or other dielectric material to prevent pipe contact with the concrete and reinforcing steel. Concrete Any type of cement and standard concrete cover over reinforcing steel may be used for concrete structures and pipe in contact with these soils. Please call if you have any questions. Respectfully Submitted, M.J. SCHIFF & ASSOCIATES, INC. Â«/tÂ«*1) U./utw *&3V James T. Keegan Enc:Table 1 z:\docs-97\971 92.doc Reviewed by: - Pall<R.64 Paul R. Smith, P.E. 1,52 -oR,,5*,A C *BACR1043 2 It*C Expg-:30.094} i \00,-A/ 11V>:,\4:n?os\.1..,Â»,4 M. J. SCHIFF & ASSOCIATES, INC. Consulting Corrosion Engineers - Since 1959 1291 North Indian Hill Boulevard Claremont, California 91711-3897 Phone 909-626-0967 FAX 909-621-1419 E-mail SCHIFFCORR@AOL.COM Table 1 - Laboratory Tests on Soil Samples Page 1 of 1 Santa Ana Police Department Building, Santa Ana, California Your #70131-7-0261.0001, MJS&A #97192 June 25,1997 Sample ID B-1 B-2A @ 3.5'@ 3.5' silty sandySoil Type sand Silt Resistivity Units as-received ohnn-cnn 23,500 7,700 saturated ohm-cm 4,750 3,500 pH 6.5 6.4 Electrical Conductivity mS/cm 0.10 0.14 Chemical Analyses Cations calcium Ca2+ mg/kg 32 88 magnesium Mg2. mg/kg 12 17 sodium Na" mg/kg 45 175 Anions carbonate C32- mg/kg ND ND bicarbonate HCO/- mg/kg 85 281 chloride Cll. mg/kg 32 273 sulfate SO42- mg/kg 108 54 Other Tests sulfide SZ. qual na na Redox mv na na ammonium NH4 ' mg/kg na na nitrate NOj mg/kg na na Electrical conductivity in millisiemens/cm and chemical analysis are of a 1:5 soil-to-water extract. mg/kg = milligrams per kilogram (parts per million) of dry soil. Redox = oxidation-reduction potential in millivolts ND = not detected na = not analyzed docs97\97192.xls CORROSION AND CATHODIC PROTECTION ENGINEERING SERVICES PLANS AND SPECIFICATIONS ' FAILURE ANALYSIS ' EXPERT WITNESS ' CORROSIVITY AND DAMAGE ASSESSMENTS