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0211-108 (CSCS) Geotechnical ReportSANTA ROSA PLAZA, L.L.C. P.O. BOX 1503 LA QUINTA, CALIFORNIA 92253 GRADING PLAN REVIEW AND FINAL GEOTECHNICAL REPORT PROPOSED EMBASSY SUITES HOTEL CALLE TAMPICO LA QUINTA, CALIFORNIA January 3, 2002 © 2002 Earth Systems Southwest Unauthorized use or copying of this document is strictly prohibited without the express written consent of Earth Systems Southwest. File No.: 07783-03 02-01-706 Earth Systems +fir/' Southwest January 3, 2002 Santa Rosa Plaza, L.L.C. P.O. Box 1503 La Quinta, California 92253 Attention: Ms. Bridget Meyers Project: Proposed Embassy Suites Hotel, Calle Tampico La Quinta, California Subject: Grading Plan Review and Final Geotechnical Report 79-811 B Country Club Drive Bermuda Dunes, CA 92201 (760)345-1588 (800)924-7015 FAX (760) 345-7315 File No.: 07783-03 02-01-706 References: 1. Earth Systems Consultants Southwest, Preliminary Geotechnical Engineering Report for Proposed Embassy Suites Hotel, File No.: 07783-01, Report No.: 00-07-705, dated August 8, 2000. 2. The Keith Companies, Project Precise Grading Plans for Tract Map 29900, Sheets 1 to 6, dated January 2, 2002. We have reviewed the preliminary geotechnical engineering report in conjunction with the project precise grading plans. The preliminary geotechnical engineering report recommended supplemental exploration after building locations were known. Supplemental subsurface exploration was conducted on April 30, 2001, using Holguin, Fahan, & Associates, Inc. of Irvine, California to advance three electric cone penetrometer (CPT) soundings to an approximate depth of 50 feet. The soundings were made at the approximate locations shown on the Site Exploration Plan, Figure 1, attached to this report. Interpretive logs of the CPT soundings are also attached to this report. CPT soundings provide a nearly continuous profile of the soil stratigraphy with readings every 5 cm (2 inch) in depth. The CPT exploration was conducted by hydraulically advancing an instrument Hogentogler 10 cm conical probe into the ground at a ground rate of 2 cm per second using a 23-ton truck as a reaction mass. An electronic data acquisition system recorded a nearly continuous log of the resistance of the soil against the cone tip (Qc) and soil friction against the cone sleeve (Fs) as the probe was advanced. Empirical relationships (Robertson and Campanella, 1989) were applied to the data to give a nearly continuous profile of the soil stratigraphy. Based on this supplemental investigation, the recommendations made in the preliminary geotechnical engineering report remain applicable without modification. Based on our review, it is our opinion that the referenced precise grading plans are in substantial compliance with the referenced soil engineering report. We make no representation as to the accuracy of the dimensions, measurements, calculations, or any portion of the design. If you January 3, 2002 -2- File No.: 07783-03 02-01-706 ^, have any questions or require additional information, please contact this office at your convenience. Respectfully submitted, EARTH SYSTEMS SOUTHWEST FF-SsroLe� w N - �,�{ CD 66 1 Shelton L. Stringer Cr Exp. 6-3a-04 J GE 2266 CK��q Letter/sls/dac F OF GP�� l Distribution: 4/Santa Rosa Plaza, L.L.C. 1/RC File 1 /BD File 1 Attachments: Figure 1 — Site Exploration Plan Logs of CPT Soundings, CPT -I, CPT-2, and CPT-3 -J _� EARTH SYSTEMS SOUTHWEST �1 �1 r•�;�Wb J__N Approximate CPT Location NTS Figure 1 - Site Exploration Plan Project: Embassy Suites Hotel, Calle Tampico File No.: 07783-03 Earth Systems �� Southwest Earth Systems ,..� gouthwest CPT Sounding : CPT-1 Cone Penetrometer: HOLGUIN, FAHAN & ASSC. w W Project Name: Santa Rosa Plaza - Embassy Suites Truck Mounted Electric Project No.: 07783-03 Cone with 21.5-ton reaction H Location: See Site Exploration Plan Date: 4/30/2001 a W Interpreted Soil Stratigraphy Friction Ratio Tip Resistance, Qc (tsq Graphic (Robertson & Campanella, 1989) Density/Consistency 8 6 4 2 0 100 200 300 400 Log Siltyand to Sandy Silt very dense Sand to Clayey Sand very dense Sandy Silt to Clayey Silt dense Silty Sand to Sandy Silt medium dense 5—Sandy Sandy Silt to Clayey Silt medium dense .:.- Silt to Clayey Silt medium dense Sandy Silt to Clayey Silt medium dense h Sandy Silt to Clayey Silt dense Silty Sand to Sandy Silt very dense 10 Overconsolidated Soil very dense Overconsolidated Soil very dense Overconsolidated Soil very dense Overconsolidated Soil very dense Overconsolidated Soil very dense 15 Overconsolidated Soil very dense Overconsolidated Soil very dense Sandy Silt to Clayey Silt _ dense - - - Sandy Silt to Clayey Silt dense _ Sand to Clayey Sand dense 20 Overconsolidated Soil dense Overconsolidated Soil medium dense Overconsolidated Soil medium dense Sand to Clayey Sand very dense Sand to Clayey Sand dense 25 Overconsolidated Soil medium dense Overconsolidated Soil medium dense Clayey Silt to Silty Clay hard Overconsolidated Soil medium dense Overconsolidated Soil medium dense 30 Overconsolidated Soil medium dense Overconsolidated Soil loose Overconsolidated Soil loose Overconsolidated Soil loose Overconsolidated Soil medium dense 35 Overconsolidated Soil _ loose Overconsolidated Soil medium dense Overconsolidated Soil medium dense Overconsolidated Soil loose Overconsolidated Soil _ medium dense f 40 Overconsolidated Soil loose Silty Clay to Clay hard Overconsolidated Soil loose Overconsolidated Soil loose Overconsolidated Soil medium dense 45 Overconsolidated Soil medium dense Overconsolidated Soil medium dense Overconsolidated Soil medium dense Overconsolidated Soil loose Overconsolidated Soil loose 50 Overconsolidated Soil loose Overconsolidated Soil loose End of Sounding @ 50.9 feet Earth Systems outhwest w CPT Sounding : CPT-2 Cone Penetrometer: HOLGUIN, FAHAN & ASSC. w Project Name: Santa Rosa Plaza - Embassy Suites Truck Mounted Electric �- Project No.: 07783-03 Cone with 21.5-ton reaction = i— Location: See Site Exploration Plan Date: 4/30/2001 a W Interpreted Soil Stratigraphy Friction Ratio (%) Tip Resistance, Qc (tsf) Graphic 0 (Robertson & Campanella, 1989) Density/Consistency 8 6 4 2 0 100 200 300 400 bog ilty Sand to Sandy Silt dense Sandy Silt to Clayey Silt very dense Sandy Silt to Clayey Silt very dense 13 Sandy Silt to Clayey Silt very dense 2 - 5 Silty Sand to Sandy Silt very dense f _ Sandy Silt to Clayey Silt very dense l Overconsolidated Soil very dense Clayey Silt to Silty Clay hard Overconsolidated Soil very dense _ 10 Overconsolidated Soil very dense Overconsolidated Soil very dense Overconsolidated Soil very dense Overconsolidated Soil dense i Overconsolidated Soil medium dense 15 Clayey Silt to Silty Clay hard Sandy Silt to Clayey Silt dense Sandy Silt to Clayey Silt dense Sandy Silt to Clayey Silt dense Overconsolidated Soil dense 20 Overconsolidated Soil dense i Overconsolidated Soil dense Overconsolidated Soil dense Sand to Clayey Sand very dense Sand to Clayey Sand very dense 25 Overconsolidated Soil medium dense Clayey Silt to Silty Clay hard Clayey Silt to Silty Clay hard Clayey Silt to Silty Clay hard Silty Clay to Clay hard 30 Silty Clay to Clay hard Silty Clay to Clay hard Silty Clay to Clay hard Silty Clay to Clay hard j Silty Clay to Clay hard 35 Silty Clay to Clay hard Silty Clay to Clay hard Clayey Silt to Silty Clay hard Silty Clay to Clay hard Overconsolidated Soil loose 40 Clayey Silt to Silty Clay very stiff Silty Clay to Clay hard Clay hard Overconsolidated Soil loose _ Overconsolidated Soil loose 45 Overconsolidated Soil very loose Overconsolidated Soil loose Clayey Silt to Silty Clay hard _ Clayey Silt to Silty Clay hard Overconsolidated Soil loose 50 Overconsolidated Soil loose Overconsolidated Soil loose End of Sounding @ 51.3 feet Earth Systems ...,�Southwest i CPT Sounding : CPT-3 Cone Penetrometer: HOLGUIN, FAHAN & ASSC. w Project Name: Santa Rosa Plaza - Embassy Suites Truck Mounted Electric Project No.: 07783-03 Cone with 21.5-ton reaction Location: See Site Exploration Plan Date: 4/30/2001 a !L Interpreted Soil Stratigraphy Friction Ratio (%) Qc (ts Tip Resistance, � Graphic (Robertson & Campanella, 1989) Density/Consistency 8 6 4 2 0 100 200 300 400 Log Sandy Silt to Clayey Silt very dense Sand to Clayey Sand verydense Sandy Silt to Clayey Silt very dense Silty Sand to Sandy Silt very dense - 5 Silty Sand to Sandy Silt very dense Silty Sand to Sandy Silt verydense Silty Sand to Sandy Silt very dense Silty Sand to Sandy Silt very dense Silty Sand to Sandy Silt _ very dense • 10 Overconsolidated Soil very dense Overconsolidated Soil very dense Overconsolidated Soil very dense Sand to Clayey Sand very dense Overconsolidated Soil very dense 15 Sandy Silt to Clayey Silt dense ;. Sandy Silt to Clayey Silt dense S Sandy Silt to Clayey Silt dense -' Sandy Silt to Clayey Silt dense Overconsolidated Soil very dense _ 20 Overconsolidated Soil verydense Overconsolidated Soil dense Overconsolidated Soil dense Sand to Clayey Sand very dense Overconsolidated Soil very dense 25 Overconsolidated Soil dense Overconsolidated Soil medium dense �► Overconsolidated Sall medium dense 0��erconsolidated Sail medium dense Overconsolidated Soil medium dense - 30 DVerconsolidated Soil medium dense Overconsolidated Soil medium dense Overconsolidated Soil loose Overconsolidated Soil medium dense Overconsolidated Soil loose 35 Clay hard f Silty Clay to Clay hard Silty Clay to Clay hard _ Clay very stiff Clay hard 40 Clayey Silt to Silty Clay very stiff Silty Clay to Clay very stiff Clay very stiff Silty Clay to Clay very stiff - Silty Clay to Clay hard 45 Silty Clay to Clay hard - — --- -- - Clay hard Overconsolidated Soil loose - — - --- -�- - �- --- ^-� Silty Clay to Clay hard Silty Clay to Clay _ hard 50 Silty Clay to Clay hard Overconsolidated Soil loose Sand to Silty Sand very loose End of Sounding @ 51.5 feet SANTA ROSA PLAZA, L.L.C. P.O. BOX 1503 LA QUINTA, CALIFORNIA 92253 FINAL REPORT OF TESTING AND OBSERVATIONS DURING GRADING PROPOSED EMBASSY SUITES HOTEL LA QUINTA, CALIFORNIA File No.: 07783-04 02-07-736 56/Z-5 off/r' Earth Systems *ter Southwest July 10, 2002 Santa Rosa Plaza, L.L.C. 1 P.O. Box 1503 La Quinta, California 92253 Attention: Mr. Dan Brown Project: Embassy Suites Hotel La Quinta, California .l Subject: Final Report of Testing and Observations Performed During Grading of the Hotel Pad 79-811B Country Club Drive Bermuda Dunes, CA 92201 (760) 345-1588 (800)924-7015 FAX (760) 345-7315 File No.: 07783-04 02-07-736 Reference: Earth Systems Southwest, Preliminary Geotechnical Engineering Report, dated August 8, 2000, Report No.: 00-07-755. Submitted herewith is a report of testing and intermittent observations performed during the grading on the above referenced project. Grading operations were performed by Dateland Construction, using conventional heavy equipment. Testing was performed as per authorization of Mr. Dan Brown. Test results are presented on the attached test report sheet with their estimated locations plotted Jon the accompanying plan. Compaction tests were performed in accordance with ASTM D 2922-81, Method A or B, and ASTM D 3017-88 Nuclear Density Test Procedures. Maximum Density -Optimum Moisture were determined in the laboratory in accordance with ASTM D 1557-91, Method A or C. Test results are as follows: f Soil Description USCS Maximum Densi J Brown silty Sand SM 112.0 pcf DISCUSSION: Optimum Moisture 15.0% The project is located north of Calle Tampico and west of Desert Club Drive in the City of La Quinta, California. July 10, 2002 - 2 - File No.: 07783-04 02-07-736 2. Prior to the site consisted of a 13.8-acre partially graded property with no grading, structures present. Vegetation consisted of dry desert sages and shrubbery with portions dominated by patches of moderately sized tamarisk trees. 3. The proposed development in this phase will include a multi -story hotel building of wood -frame and stucco exterior. 4. This report includes testing of the proposed hotel building. 5. The scope of our work was based on the referenced preliminary geotechnical engineering report, and plans and staking by the Keith Companies. 6_ The site was cleared of existing vegetation and debris prior to the start of grading operations. 7. The building area was over -excavated to a depth of 8 feet below finish pad grade during site grading. The exposed surface was moisture conditioned and compacted. 8. Fill materials consisting of on -site soils were placed in thin layers and compacted into place. 9. A total of 38 compaction tests were performed. 10. Test results indicate that a minimum of ninety (90) percent of maximum dry density has been obtained in the areas tested. 11. The test locations are approximate and are determined by pacing and sighting from prominent field features. In our work, we have relied on topographic and survey information provided by others. -1 12. Based upon intermittent observations and testing during the fine grading operations, on May 7 through May 22, 2002, on this project, it is our opinion that the intent of the ] recommendations of the referenced geotechnical engineering report as well as the ordinance of the City of La Quinta, have essentially been complied with. 13. As used herein, the term "observation" implies only that we observed the progress of work we agreed to be involved with, and performed tests on which together we based our opinion as to whether the work essentially complies with the job requirements. We make no warranty, express or implied, except that our services are performed in accordance with engineering principles generally accepted at this time and location. J14. With any manufactured product, there are statistical variations in its uniformity and in the accuracy of tests used to measure its quality. As compared with other manufactured J products, field construction usually presents large statistical variations in its uniformity and accuracy of test results used to measure its quality. Thus, even with very careful observation and testing, it cannot be said that all parts of the product comply with the job J requirements and the degree of certainty is greater with full-time observation than it is with intermittent observations and testing. Therefore, our opinion, based on observing JEARTH SYSTEMS SOUTHWEST July 10, 2002 - 3 - File No.: 07783-04 02-07-736 and testing the work means that there is only a statistically based, reasonable certainty that the work essentially complies with the job requirements. 15. It is recommended that Earth Systems Southwest (ESSW) be provided the opportunity for a general review of any changes to the final design and/or location of the proposed structures in order that earthwork and foundation recommendations may be properly interpreted. If ESSW is not accorded the privilege of making this recommended review, we can assume no responsibility for misinterpretation of our recommendations. 16. This report is issued with the understanding that it is responsibility of the owner, or of his representative, to ensure that the information and recommendations contained herein are called to the attention of the architect and engineers for the project and are incorporated into the plans and specifications for the project. It is also the owner's responsibility, or his representative, to ensure that the necessary steps are taken to see that the general contractor and all subcontractors carry our such recommendations in the field. It is further understood that the owner or his representative is responsible for submittal of this report to the appropriate governing agencies. If there are any questions concerning this report, please do not hesitate to contact this office. Respectfully submitted, EARTH SYSTEMS SOUTHWEST MA Mario Aparicio Field Technician Grading/ma/csh/dac Distribution: 4/Santa Rosa Plaza, LLC 1/RC File 2/BD File Reviewed ,, OOESS►oN � av�y'G S. Z CE 38234 rn 'u EXP.03/31105 IT Craig S CE 382 OF CA.V%f EARTH SYSTEMS SOUTHWEST REPORT OF RELATIVE COMPACTIONS JOB NAME: Embassy Suites Hotel LOCATION: La Quinta, California JOB NO: 07783-04 REPORT NO: 02-07-736 Page 1 of 2 Test No Date Tested Description Elevation (feet) %Moisture Dry Density Relative Maximum Ln Place In Place Compaction Density Grading 1 05/07/02 Per Plan 8.0 BPG 16.0 108.8 96 112.0 2 05/07/02 Per Plan 7.0 BPG 20.1 102.2 90 112.0 3 05/07/02 Per Plan 6.0 BPG 17.0 101.8 90 112.0 4 05/07/02 Per Plan 8.0 BPG 15.1 108.7 96 112.0 5 05/07/02 Per Plan 7.0 BPG 16.7 111.7 98 112.0 6 05/07/02 Per Plan 6.0 BPG 18.3 101.5 90 112.0 7 05/09/02 Per Plan 6.0 BPG 12.9 104.8 93 112.0 8 05/09/02 Per Plan 5.0 BPG 9.8 101.3 90 112.0 9 05/09/02 Per Plan 4.0 BPG 14.4 102.8 91 112.0 10 05/08/02 Per Plan 8.0 BPG 18.2 105.2 94 112.0 11 05/08/02 Per Plan 7.0 BPG 11.2 102.7 92 112.0 12 05/08/02 Per Plan 6.0 BPG 18.6 104.7 93 112.0 13 05/14/02 Per Plan 5.0 BPG 14.9 107.6 96 112.0 14 05/14/02 Per Plan 4.0 BPG 14.5 109.9 98 112.0 15 05/14/02 Per Plan 3.0 BPG 11.1 109.6 98 112.0 16 05/14/02 Per Plan 3.0 BPG 17.4 103.0 92 112.0 17 05/14/02 Per Plan 2.0 BPG 17.0 105.5 94 112.0 18 05/16/02 Per Plan 1.0 BPG 13.5 108.0 96 112.0 19 05/16/02 Per Plan 2.0 BPG 16.9 104.2 93 112.0 20 05/16/02 Per Plan 3.0 BPG 16.7 103.3 92 112.0 21 05/16/02 Per Plan 2.0 BPG 16.7 102.8 92 112.0 22 05/16/02 Per Plan 1.0 BPG 15.9 106.6 95 112.0 23 05/17/02 Per Plan FPG 15.3 99.6 90 112.0 24 05/17/02 Per Plan 1.0 BPG 11.7 107.3 97 112.0 25 05/17/02 Per Plan FPG 13.7 105.4 95 112.0 26 05/17/02 Per Plan 5.0 BPG 7.5 97.2 87* 112.0 27 05/17/02 Per Plan FPG 12.7 102.4 92 112.0 28 05/20/02 Retest #26 11.3 104.2 93** 112.0 29 05/20/02 Per Plan 3.5 BPG 9.8 103.3 92 112.0 30 05/20/02 Per Plan 2.0 BPG 10.3 102.8 92 112.0 31 05/20/02 Per Plan 1.0 BPG 12.1 106.6 95 112.0 IJuly 10, 2002 EARTH SYSTEMS SOUTHWEST C6, ldy�- j REPORT OF RELATIVE COMPACTIONS JOB NAME: Embassy Suites Hotel ILOCATION: La Quinta, California I JOB NO: 07783-04 REPORT NO: 02-07-736 Pa e2of2 Test No Date Tested Description Elevation (feet) '%Moisture Dry Density Relative Maximum [n Place In Place Compaction Density 32 05/20/02 Per Plan FPG 13.3 102.4 92 112.0 33 05/20/02 Per Plan 4.0 BPG 14.8 107.6 96 112.0 34 05/20/02 Per Plan 2.5 BPG 13.6 103.0 92 112.0 35 05/20/02 Per Plan 1.0 BPG 12.5 105.5 94 112.0 36 05/20/02 Per Plan FPG 10.9 103.2 92 112.0 37 5/22/02 Per Plan FPG 9.6 106.7 95 112.0 38 5/22/02 Per Plan FPG 10.7 107.7 96 112.0 BPG = Below Pad Grade FPG = Finish Pad Grade * = Failing Test ** = Passing Retest July 10, 2002 EARTH SYSTEMS SOUTHWEST C6. py� �Z - rCfAli �,F MAM4 a ,�` Sri „��__J.7�a.�,•,.'�,yL�� •V.�t� ��I�w, �h�vwr+nii �_wf(...- �. •.n�" �� .. +—. � .. �,—�,p .[n—» Ir` Y4— ;9rs BISON HOTEL GROUP, L.L.C. 49-105 BARRYMORE ROAD INDIO, CALIFORNIA 92201 PRELIMINARY GEOTECHNICAL ENGINEERING REPORT PROPOSED EMBASSY SUITES HOTEL CALLE TAMPICO LA QUINTA, CALIFORNIA File No.: 07783-01 00-07-755 , Earth Systems Consultants Southwest August 8, 2000 Bison Hotel Group, L.L.P. 49-105 Barrymore Road Indio, California 92201 Attention: Mr. Dan Brown Project: Proposed Embassy Suites Hotel, Calle Tampico La Quinta, California 79-811B Country Club Drive Bermuda Dunes, CA 92201 (760)345-1588 (800)924-7015 FAX (760) 345-7315 Subject: PRELIMINARY GEOTECHNICAL ENGINEERING REPORT Dear Mr. Brown: File No.: 07783-01 00-07-755 We take pleasure to present this Geotechnical Engineering Report prepared for the proposed Embassy Suites Hotel to be located on the northwest corner of Calle Tampico and Desert Club Drive in the City of La Quinta, California. This report presents our findings and recommendations for site grading and foundation design, incorporating the tentative information supplied to our office. This report should stand as a whole, and no part of the report should be excerpted or used to the exclusion of any other part. This report completes our scope of services in accordance with our agreement, dated June 5, 2000. Other services that may be required, such as plan review and grading observation are additional services and will be billed according to the Fee Schedule in effect at the time services are provided. Unless requested in writing, the client is responsible to distribute this report to the appropriate governing agency or other members of the design team. We appreciate the opportunity to provide our professional services. Please contact our office if there are any questions or comments concerning this report or its recommendations. Respectfully submitted, EARTH SYSTEMS CONSULTANTS Southwest QRaFESS�aN,g L S o�A $t w U) No. 2266 cc Shelton L. Stringer Exp. 6-30-04 GE 2266 0:1 OrECHN��'Pi�` � 9�E OF CA. SER/sls Distribution: 5/ Bison Hotel Group, L.L.P. l/ Korve Engineering, Mr. Eldon Lee INTA File 2/BD File TABLE OF CONTENTS Page Section1 INTRODUCTION..................................................................................................1 1.1 Project Description.......................................................................-----..............1 1.2 Site Description........................................................................................................1 1.3 Purpose and Scope of Work.....................................................................................2 Section 2 METHODS OF INVESTIGATION.....................................................................3 2.1 Field Exploration.....................................................................................................3 2.2 Laboratory Testing............................................•----..................................................3 Section3 DISCUSSION.........................................................................................................5 3.1 Soil Conditions........................................................................................................5 3.2 Groundwater............................................................................................................5 3.3 Geologic Setting......................................................................................................5 3.4 Geologic Hazards .................. -................................ ............................. .................... 6 3.4.1 Seismic Hazards...........................................................................................6 3.4.2 Secondary Hazards.......................................................................................7 3.4.3 Site Acceleration and UBC Seismic Coefficients ....................... ......... ..... —8 Section 4 CONCLUSIONS..................................................................................................11 ' Section 5 PRELIMINARY RECOMMENDATIONS.......................................................12 SITE DEVELOPMENT AND GRADING......................................................................12 5.1 Site Development - Grading..................................................................................12 5.2 Excavations and Utility Trenches .................................. ....... .............. - ................. 13 5.3 Slope Stability of Graded Slopes .................................. 13 STRUCTURES...... ....................................................................................................14 5.4 Foundations............................................................................................................14 5.5 Slabs-on-Grade......................................................................................................15 5.6 Retaining Walls. .16 5.7 Mitigation of Soil Corrosivity on Concrete...........................................................17 5.8 Seismic Design Criteria.........................................................................................17 5.9 Pavements.......................................................•-..................................................---18 Section 6 LIMITATIONS AND ADDITIONAL SERVICES..........................................19 6.1 Uniformity of Conditions and Limitations.............................................................19 6.2 Additional Services................................................................................................20 REFERENCES...............................................................................................................21 _-1 APPENDIX A Figure 1- Site Location Map Figure 2 - Boring Location Map Table 1 Fault Parameters 1997 UBC Seismic Parameters 2000 IBC Seismic Parameters Logs of Borings APPENDIX B Laboratory Test Results EARTH SYSTEMS CONSULTANTS SOUTHWEST :7 J August 8, 2000 - 1 - File No.: 07783-01 00-07-755 Section 1 INTRODUCTION 1.1 Project Description �j This Geotechnical Engineering Report has been prepared for the proposed Embassy Suites Hotel J to be located on the northwest corner of Calle Tampico and Desert Club Drive in the City of La Quinta, California. The proposed Hotel will be a six -story structure. We understand that the proposed structure will be of steel frame construction and will be supported by conventional shallow continuous or pad footings. Five other single -story buildings are planned that range from 3500 to 10,000-sf. Site development will include site grading, building pad preparation, underground utility installation, street and parking lot construction, and concrete driveway and sidewalk placement. We used maximum column loads of 300 kips and a maximum wall loading of 12 kips per linear foot as a basis for the foundation recommendations. All loading is assumed to be dead plus actual live load if actual structural loading is to exceed these assumed values, we might need to reevaluate the given recommendations. 1.2 Site Description The proposed six -story hotel is to be constructed on a 13.8-acre site as shown on Figure 1 in Appendix A. The site is generally undeveloped property with no structures present. The majority of the site consisted of dried desert sages and shrubbery with portions dominated by patches of moderate sized tamarisk trees. A large portion of the site was compacted soil, particularly in the southern area near Calle Tampico. The compacted zone was demarcated from the remainder of the site by a two- to three-foot high berm extending across the site about 250 feet north of Calle Tampico. The site contained numerous piles of common household and construction debris scattered throughout. Several large vegetation piles were located in the western area behind the small businesses. Evidence of a homeless or transient community was observed west of the center of the site. Several large burn areas were located at the site, particularly to the northwest. The site is generally bounded to the north by a chain link fence atop a ten to fifteen foot berm separating the site from a golf course, to the east by Desert Club Drive, to the south by Calle Tampico, to the southwest by three small commercial businesses, and to the west by Avenida - Bermudas and vacant land. The elevation of the site is approximately 40 feet above mean sea level and the terrain is relatively flat. Surface water in the area generally drains by sheet flow to the northeast and east. �1 There are underground utilities along Calle Tampico and Desert Club Drive. These utility lines include but are not limited to domestic water, telephone, sewer, and irrigation lines. EARTH SYSTEMS CONSULTANTS SOUTHWEST August 8, 2000 - 2 - File No.: 07783-01 00-07-755 1.3 Purpose and Scope of Work The purpose for our services was to evaluate the site soil conditions and to provide professional opinions and recommendations regarding the proposed development of the site. The scope of work included the following: ➢ A general reconnaissance of the site. ➢ Shallow subsurface exploration by drilling 9 exploratory borings to depths ranging from 16.5 to 51.5 feet. ➢ Laboratory testing of selected soil samples obtained from the exploratory borings. ➢ Review of selected published technical literature pertaining to the site ➢ Engineering analysis and evaluation of the acquired data from the exploration and testing programs. ➢ A summary of our findings and recommendations in this written report. This report contains the following: ➢ Discussions on subsurface soil and groundwater conditions. ➢ Discussions on regional and local geologic conditions. ➢ Discussions on geologic and seismic hazards. ➢ Graphic and tabulated results of laboratory tests and field studies. ➢ Recommendations regarding: • Site development and grading criteria, • Excavation conditions and buried utility installations, • Structure foundation type and design, • Allowable foundation bearing capacity and expected total and differential settlements, • Concrete slabs -on -grade, Lateral earth pressures and coefficients, • Mitigation of the potential corrosivity of site soils to concrete and steel reinforcement, • Seismic design parameters, • Pavement structural sections. Not _Contained In This Report: Although available through Earth Systems Consultants Southwest, the current scope of our services does not include: ➢ A corrosive study to determine cathodic protection of concrete or buried pipes. ➢ An environmental assessment. ➢ Investigation for the presence or absence of wetlands, hazardous or toxic materials in the soil, surface water, groundwater, or air on, below, or adjacent to the subject property. ➢ Design -level, final geotechnical report with structure -specific soil borings. This preliminary report is intended for planning purposes only and not for final design or construction. A final geotechnical report should be prepared with structure -specific soil borings once site development plans are complete. EARTH SYSTEMS CONSULTANTS SOUTHWEST August 8, 2000 - 3 - File No.: 07783-01 00-07-755 Section 2 METHODS OF INVESTIGATION 2.1 Field Exploration Nine exploratory borings were drilled to depths ranging from 16.5 to 51.5 feet below the existing ground surface to observe the soil profile and to obtain samples for laboratory testing. The borings were drilled on June 7, 2000 using 8-inch outside diameter hollow -stem augers, and powered by a Mobile B61 truck -mounted drilling rig. The boring locations are shown on the boring location map, Figure 2, in Appendix A. The locations shown are approximate, established _ l by pacing and sighting from existing topographic features. Samples were obtained within the test borings using a Standard Penetration (SPT) sampler (ASTM D 1586) and a Modified California (MC) ring sampler (ASTM D 3550 with shoe similar I to ASTM D 1586). The SPT sampler has a 2-inch outside diameter and a 1.38-inch inside diameter. The MC sampler has a 3-inch outside diameter and a 2.37-inch inside diameter. The samples were obtained by driving the sampler with a 140-pound downhole hammer dropping 30 inches in general accordance with ASTM D 1586. Recovered soil samples. were sealed in containers and returned to the laboratory. Bulk samples were also obtained from auger cuttings, representing a mixture of soils encountered at the depths noted. The final logs of the borings represent our interpretation of the contents of the field logs and the results of laboratory testing performed on the samples obtained during the subsurface investigation. The final logs are included in Appendix A of this report. The stratification lines represent the approximate boundaries between soil types although the transitions, however, may be gradational. 2.2 Laboratory Testing Samples were reviewed along with field logs to select those that would be analyzed further. Those selected for laboratory testing include soils that would be exposed and used during i grading, and those deemed to be within the influence of the proposed structure. Test results are presented in graphic and tabular form in Appendix B of this report. The tests were conducted in general accordance with the procedures of the American Society for Testing and Materials (ASTM) or other standardized methods as referenced below. Our testing program consisted of the following: ➢ In -situ Moisture Content and Unit Dry Weight for the ring samples (ASTM D 2937). ➢ Maximum density tests were performed to evaluate the moisture -density relationship of typical soils encountered (ASTM D 1557-91). ➢ Particle Size Analysis (ASTM D 422) to classify and evaluate soil composition. The Jgradation characteristics of selected samples were made by hydrometer and sieve analysis procedures. EARTH SYSTEMS CONSULTANTS SOUTHWEST August 8, 2000 - 4 - File No.: 07783-01 00-07-755 ➢ Consolidation (Collapse Potential) (ASTM D 2435 and D5333) to evaluate the compressibility and hydroconsolidation (collapse) potential of the soil. ➢ Expansion index tests (UBC Test Method 18-2) to evaluate the expansive nature of the soil. The samples were surcharged under 144 pounds per square foot at moisture content of near 50% saturation. Samples were then submerged in water for 24 hours and the amount of expansion was recorded with a dial indicator. ➢ Liquid and Plastic Limits tests to evaluate the plasticity and expansive nature of clayey 1 soils. ➢ Chemical Analyses (Soluble Sulfates & Chlorides, pH, and Electrical Resistivity) to evaluate the corrosivity of the soil on concrete and steel. EARTH SYSTEMS CONSULTANTS SOUTHWEST August 8, 2000 - 5 - File No.: 07783-01 00-07-755 Section 3 DISCUSSION 3.1 Soil Conditions The field exploration indicates that site soils consist primarily of medium dense to very dense Silty Sand, Silt, Sandy Silt, and very stiff to hard Clayey Silt (Unified Soil Classification Symbols of SM, ML, and ML/CL, respectively). The boring logs provided in Appendix A include more detailed descriptions of the soils encountered. An Expansion test indicates the sandy silt soils to be in the very low expansion category in accordance with Table 18A-I-B of the Uniform Building Code. The plasticity indices (PI 9 to 13) indicate the clayey silt to be in the low expansion category. In and climatic regions, granular soils may have a potential to collapse upon wetting. Collapse (hydroconsolidation) may occur when the soluble cements (carbonates) in the soil matrix dissolve, causing the soil to densify from its loose configuration from deposition. Consolidation tests indicate 0.7% or less collapse upon inundation and are considered a slight site risk. The I hydroconsolidation potential is commonly mitigated by recompaction of a zone beneath building pads. J The site lies within a recognized blow sand hazard area. Fine particulate matter (PM10) can create an air quality hazard if dust is blowing. Watering the surface, planting grass or landscaping, or hardscape normally mitigates this hazard. 3.2 Groundwater Free groundwater was not encountered in the borings during exploration. The depth to groundwater at the site was evaluated by contacting the Regional Water Quality Control Board (RWQCB). Ms. Yetunde Omilana of the RWQCB reports the depth to groundwater at the subject site is about 130 to 140 feet, based on data from a monitoring well located near the southwest corner of the site. Groundwater flow under the site is anticipated to be toward the northeast due to the location of the nearby mountains. Groundwater levels may fluctuate with regional drawdown from pumping from nearby wells. The groundwater levels reported may not represent a permanent condition. Hydrographs of nearby wells indicate that groundwater levels have dropped dramatically (30 to 70-feet) in the north La Quinta cove area in the last twenty years. This corresponds to the increased water usage from the rapid growth of the City of La Quinta and golf course development. 3.3 Geologic Setting Regional Geology: The site lies within the Coachella Valley, a part of the Colorado Desert geomorphic province. A significant feature within the Colorado Desert geomorphic province is the Salton Trough. The Salton Trough is a large northwest -trending structural depression that extends from San Gorgonio Pass, approximately 180 miles to the Gulf of California. Much of this depression in the area of the Salton Sea is below sea level. EARTH SYSTEMS CONSULTANTS SOUTHWEST August 8, 2000 - 6 - File No.: 07783-01 00-07-755 The Coachella Valley forms the northerly portion of the Salton Trough. The Coachella Valley contains a thick sequence of sedimentary deposits that are Miocene to recent in age. Mountains surrounding the Coachella Valley include the Little San Bernardino Mountains on the northeast, foothills of the San Bernardino Mountains on the northwest, and the San Jacinto and Santa Rosa Mountains on the southwest. These mountains expose primarily Precambrian metamorphic and Mesozoic granitic rocks. The San Andreas Fault zone within the Coachella Valley consists of the Garnet Hill Fault, the Banning Fault, and the Mission Creek Fault that traverse along the northeast margin of the valley. Local Gealo.,y. The project site lies at an elevation of about 40-feet above mean sea level in the lower part of the La Quinta Cove portion of the Coachella Valley. The La Quinta Cove is situated on an alluvial wedge between two granite mountain spurs of the Santa Rosa Mountains. The waters of ancient Lake Cahuilla once covered the project site. The sediments within the cove consist of fine to coarse -grained sands with interbedded clays, silts, and gravels of aeolian (wind-blown), alluvial (water laid), and lacustrine (lake bed) origin. The site is located near the boundary between the lacustrine deposits of ancient Lake Cahuilla, and alluvial deposits from the Santa Rosa Mountains to the south. Geohydologic Settling: The site lies within the Thermal subbasin of the Coachella Valley groundwater basin. The Thermal subbasin is subdivided into four generalized zones: a semi perched zone with alternating clay layers to about 100 foot depth, underlain by a upper and lower aquifer, separated by an aquitard layer. Domestic wells in the region derive their water from the upper and lower aquifers, generally from about 200 to 1000 feet deep. 3.4 Geologic Hazards Geologic hazards that may affect the region include seismic hazards (surface fault rupture, ground shaking, soil liquefaction, and other secondary earthquake -related hazards), slope instability, flooding, ground subsidence, and erosion. A discussion follows on the specific hazards to this site. 3.4.1 Seismic Hazards Seismic Sources: Our research of regional faulting indicates that several active faults or seismic zones lie within 62 miles (100 kilometers) of the project site as shown on Table 1 in j Appendix A. The primary seismic hazard to the site is strong groundshaking from earthquakes along the San Andreas and San Jacinto Faults. The. Maximum Magnitude Earthquake (M,,.) listed is from published geologic information available for each fault (CDMG, 1996). The Mmax corresponds to the maximum earthquake believed to be tectonically possible. Surface Fault Rupture: The project site does not lie within a currently delineated State of California, Alquist-Priolo Earthquake Fault Zone (Hart, 1994). Well -delineated fault lines cross through this region as shown on California Division of Mines and Geology (CDMG) maps l(Jennings, 1994). Therefore, active fault rupture is unlikely to occur at the project site. While I fault rupture would most likely occur along previously established fault traces, future fault rupture could occur at other locations. EARTH SYSTEMS CONSULTANTS SOUTHWEST W August 8, 2000 - 7 - File No.: 07783-01 00-07-755 Historic Seismicity: Six historic seismic events (5.9 M or greater) have significantly affected the Coachella Valley this century. They are as follows: • Desert Hot Springs Earthquake - On December 4, 1948, a magnitude 6.5 ML (6.OMW) earthquake occurred east of Desert Hot Springs. This event was strongly felt in the Palm Springs area. ■ Palm Springs Earthquake - A magnitude 5.9 ML (6.2MW) earthquake occurred on July 8, 1986 in the Painted Hills causing minor surface creep of the Banning segment of the San Andreas Fault. This event was strongly felt in the Palm Springs area and caused structural damage, as well as injuries. • Joshua Tree Earthquake - On April 22, 1992, a magnitude 6.1 ML (6.1MW) earthquake occurred in the mountains 9 miles east of Desert Hot Springs. Structural damage and minor injuries occurred in the Palm Springs area as a result of this earthquake. • Landers & Big Bear Earthquakes - Early on June 28, 1992, a magnitude 7.5 Ms (7.3MW) earthquake occurred near Landers, the largest seismic event in Southern California for 40 years. Surface rupture occurred just south of the town of Yucca Valley and extended some 43 miles toward Barstow. About three hours later, a magnitude 6.6 Ms (6.4MW) earthquake occurred near Big Bear Lake. No significant structural damage from these earthquakes was reported in the Palm Springs area. • Hector Mine Earthquake - On October 16, 1999, a magnitude 7.1MW earthquake occurred on the Lavic Lake and Bullion Mountain Faults north of 29 Palms. This event while widely felt, no significant structural damage has been reported in the Coachella Valley. Seismic Risk: While accurate earthquake predictions are not possible, various agencies have conducted statistical risk analyses. In 1996, the California Division of Mines and Geology (CDMG) and the United States Geological Survey (USGS) completed the latest generation of probabilistic seismic hazard maps for use in the 1997 UBC. We have used these maps in our evaluation of the seismic risk at the site. The Working Group of California Earthquake Probabilities (WGCEP, 1995) estimated a 22% conditional probability that a magnitude 7 or greater earthquake may occur between 1994 to 2024 along the Coachella segment of the San Andreas Fault. The primary seismic risk at the site is a potential earthquake along the San Andreas Fault. Geologists believe that the San Andreas Fault has characteristic earthquakes that result from rupture of each fault segment. The estimated characteristic earthquake is magnitude 7.4 for the Southern Segment of the fault. This segment has the longest elapsed time since rupture than any other portion of the San Andreas Fault. The last rupture occurred about 1690 AD, based on dating by the USGS near Indio (WGCEP, 1995). This segment has also ruptured on about 1020, 1300, and 1450 AD, with an average recurrence interval of about 220 years. The San Andreas Fault may rupture in multiple segments producing a higher magnitude earthquake. Recent paleoseismic studies suggest that the San Bernardino Mountain Segment to the north and the Coachella Segment may have both ruptured together in 1450 and 1690 AD (WGCEP, 1995). 3.4.2 Secondary Hazards Secondary seismic hazards related to ground shaking include soil liquefaction, ground deformation, areal subsidence, tsunamis, and seiches. The site is far inland so the hazard from tsunamis is non-existent. At the present time, no water storage reservoirs are located in the immediate vicinity of the site. Therefore, hazards from seiches are considered negligible at this time. EARTH SYSTEMS CONSULTANTS SOUTHWEST August 8, 2000 - 8 - File No.: 07783-01 00-07-755 Soil Liquefaction: Liquefaction is the loss of soil strength from sudden shock (usually earthquake shaking), causing the soil to become a fluid mass. In general, for the effects of liquefaction to be manifested at the surface, groundwater levels must be within 50 feet of the ground surface and the soils within the saturated zone must also be susceptible to liquefaction. The potential for liquefaction to occur at this site is considered negligible because the depth of i groundwater beneath the site exceeds 50 feet. No free groundwater was encountered in our exploratory borings. In addition, the project does not lie within the Riverside County liquefaction study zone. Ground Deformation: Non -tectonic ground deformation consists of cracking of the ground with little to no displacement. This type of deformation is generally associated with differential shaking of two or more geologic units with differing engineering characteristics. Ground deformation may also be caused by liquefaction. As the site is relatively flat with consistent geologic material, and has a low potential for liquefaction, the potential for ground deformation is also considered to be low. Land Subsidence: Land subsidence occurs when the groundwater levels drop to cause an increase in effective overburden stress to underlying sediments and resulting in further consolidation of these sediments. As the sediments consolidate to this increased stress, subsidence of the ground occurs. Land subsidence is common in valleys containing aquifer systems that are in part composed of fine-grained sediments and have undergone extensive groundwater development. The CVVWD has commissioned a study through the U.S. Geological Survey in 1996 to monitor land subsidence because of groundwater withdrawal (Ikehara, et al, 1996). Land subsidence has historically occurred in the lower Coachella Valley, because of the decline in groundwater levels from pumping prior to the import of Colorado River water, beginning in 1949. However, since the 1970's, the demand for water has exceeded the import of water and increased pumping has again lowered the groundwater table. Therefore, there is a potential for land subsidence occurring across the project site. Expected subsidence is expected to be relatively uniform. The magnitude of any differential settlement (if any) that may be detrimental to structures is not known. Slope Instability: The site is relatively flat. Therefore, potential hazards from slope instability, landslides, or debris flows are considered negligible. Flooding: The project site does not lie within a designated FEMA 100-year flood plain. The project site may be in an area where sheet flooding and erosion could occur. If significant changes are proposed for the site, appropriate project design, construction, and maintenance can minimize the site sheet flooding potential. 3.4.3 Site Acceleration and UBC Seismic Coefficients Site Acceleration: The potential intensity of ground motion may be estimated from the horizontal peak ground acceleration (PGA), measured in "g" forces. Included in Table 1 are deterministic estimates of site acceleration from possible earthquakes at nearby faults. Ground motions are dependent primarily on the earthquake magnitude and distance to the seismogenic EARTH SYSTEMS CONSULTANTS SOUTHWEST 1 August 8, 2000 - 9 - File No.: 07783-01 00-07-755 (rupture) zone. Accelerations also are dependent upon attenuation by rock and soil deposits, direction of rupture, and type of fault. For these reasons, ground motions may vary considerably in the same general area. This variability can be expressed statistically by a standard deviation about a mean relationship. The PGA is an inconsistent scaling factor to compare to the UBC Z factor and is generally a poor indicator of potential structural damage during an earthquake. Important factors influencing the structural performance are the duration and frequency of strong ground motion, local subsurface conditions, soil -structure interaction, and structural details. Because of these factors, an effective peak acceleration (EPA) is used in structural design. The following table provides the probabilistic estimate of the PGA and EPA taken from the 1996 CDMG/USGS seismic hazard maps. Estimate of PGA and EPA from 1996 CDMG/USGS Probabilistic Seismic Hazard Maas Equivalent Spectral Spectral Risk of Exceedance Return PGA EPA Acceleration Acceleration Period (years) (g) (1) (g) (2) Sa 0.3 sec. Sa (1.0 sec.) 10% in 50 years 475 0.46 0.43 1.07 0.42 Notes: 1. Based on a soft rock site, SB/c and soil amplification factor of 1.0 for Soil Profile Type SD. 2. Spectral acceleration (SA) at period of 0.3 seconds divided by 2.5 for 5% damping, as defined by the Structural Engineers Association of California (SEAOC, 1996). 1997 UBC Seismic Coefficients: The Uniform Building Code (LTBC) seismic design are based on a Design Basis Earthquake (DBE) that has an earthquake ground motion with a 10% probability of occurrence in 50 years. The PGA and EPA estimates given above are _l provided for information on the seismic risk inherent in the UBC design. The following lists the 1 seismic and site coefficients given in Chapter 16 of the 1997 Uniform Building Code (UBC). 1997 UBC Seismic Coefficients for Chapter 16 Seismic Provisions Seismic Zone: 4 Seismic Zone Factor, Z: 0.4 Soil Profile Type: SD Seismic Source Type: A Closest Distance to Known Seismic Source: 12.4 km = 8.6 miles Near Source Factor, Na: 1.00 Near Source Factor, Nv: 1.10 Seismic Coefficient, Ca: 0.44 = 0.44Na Seismic Coefficient, Cv: 0.71 = 0.64Nv R Pf-rPnrP Figure 16-2 Table 16-I Table 16-J Table 16-U (San Andreas Fault) Table 16-S Table 16-T Table 16-Q Table 16-R IEARTH SYSTEMS CONSULTANTS SOUTHWEST August 8, 2000 - 10 - File No.: 07783-01 00-07-755 Seismic Zoning: The Seismic Safety Element of the 1984 Riverside County General Plan establishes groundshaking hazard zones. The project area is mapped in Ground Shaking Zone IIIB. Ground Shaking Zones are based on distance from causative faults and underlying soil types. The site does not lie within the Liquefaction Hazard area established by this Seismic Safety Element. These groundshaking hazard zones are used in deciding suitability of land use. 2000 IBC Seismic Coefficients: For comparative purposes, the newly released 2000 International Building Code (IBC) seismic and site coefficients are given in Appendix A. As of the issuance of this report, we are unaware when governing jurisdictions may adopt or modify the IBC provisions. EARTH SYSTEMS CONSULTANTS SOUTHWEST -1 August 8, 2000 - 11 - File No.: 07783-01 00-07-755 Section 4 CONCLUSIONS The following is a summary of our conclusions and professional opinions based on the data obtained from a review of selected technical literature and the site evaluation. ➢ The primary geologic hazard relative to site development is severe ground shaking from earthquakes originating on nearby faults. In our opinion, a major seismic event originating on the local segment of the San Andreas or San Jacinto Fault zones would be the most likely cause of significant earthquake activity at the site within the estimated design life of the proposed development. ➢ The project site is in seismic Zone 4 as defined in the Uniform Building Code. A qualified professional who is aware of the site seismic setting should design any permanent structure constructed on the site. ➢ Ground subsidence from seismic events, hydroconsolidation, and groundwater withdrawal is a potential hazard in the lower La Quinta cove of the Coachella Valley. Adherence to the following grading and structural recommendations should reduce potential settlement problems from seismic forces, heavy rainfall or irrigation, flooding, and the weight of the intended structures. ➢ The soils are susceptible to wind and water erosion. Preventative measures to minimize seasonal flooding and erosion should be incorporated into site grading plans. Dust control should also be implemented during construction. ➢ Other geologic hazards including ground rupture, liquefaction, seismically induced flooding, and landslides are considered low or negligible on this site. ➢ The upper soils were found to be relatively medium dense to dense sands, silts, and very stiff to hard, expansive clayey silts. In our opinion, the soils within the building area will require over excavation and recompaction to improve bearing capacity and reduce settlement from static loading. Soils should be readily cut by normal grading equipment. ➢ Earth Systems Consultants Southwest (ESCSW) should provide geotechnical engineering services during project design, site development, excavation, grading, and foundation construction phases of the work. Structure -specific borings should be conducted to confirm the preliminary findings of this report once a site development plan is completed. This is to allow for possible changes in these preliminary recommendations and design in the event that subsurface conditions differ from those encountered in this feasibility study. ➢ Plans and specifications should be provided to ESCSW prior to grading. Plans should include the grading plans, foundation plans, and foundation details. Preferably, structural loads should be shown on the foundation plans. EARTH SYSTEMS CONSULTANTS SOUTHWEST August 8, 2000 -12- File No.: 07783-01 00-07-755 Section 5 PRELIMINARY RECOMMENDATIONS SITE DEVELOPMENT AND GRADING 5.1 Site Development - Grading A representative of ESCSW should observe site grading and the bottom of excavations prior to placing fill. Local variations in soil conditions may warrant increasing the depth of recompaction and over -excavation. Clearing and Grubbing: Prior to site grading existing vegetation, trees, large roots, construction debris, and trash should be removed from the proposed building and pavement areas. The surface should be stripped of organic growth and removed from the construction area. Areas disturbed during clearing should be properly backfilled and compacted as described below. Building Pad Preparation: Because of the relatively non -uniform and nature of the majority of the 1 site soils, we recommend recompaction of soils in the building area. The existing surface soils within the hotel building pad area should be over -excavated to 60 inches below existing grade or a minimum of 48 inches below the footing level (whichever is lower). For single -story structures, the building pad area should be over -excavated to 36 inches below existing grade or a minimum of 24 inches below the footing level (whichever is lower). The over -excavation _ should extend for 5 feet beyond the outer edge of exterior footings. The bottom of the sub - excavation should be scarified; moisture conditioned, and recompacted to at least 90 % relative compaction (ASTM D 1557) for an additional depth of 12 inches. Subgrade Preparation: In areas to receive fill, pavements, or hardscape, the ground surface should be scarified; moisture conditioned, and compacted to at least 90% relative compaction (ASTM D 1557) for a depth of 12 inches below finished subgrades. Compaction should be verified by testing. Engineered Fill Soils: The native silty sand and sandy soil is suitable for use as engineered fill and utility trench backfill. The native clayey silt soils are not suitable for engineered fill beneath the upper two feet of subgrade for structures, but may be used elsewhere. The native soil should be placed in maximum 8-inch lifts (loose) and compacted to at least 90% relative compaction (ASTM D 1557) near its optimum moisture content. Compaction should be verified by testing. Imported fill soils (if required) should be non -expansive, granular soils meeting the USCS classifications of SM, SP-SM, or SW-SM with a maximum rock size of 3 inches and 5 to 35% passing the No. 200 sieve. The geotechnical engineer should evaluate the import fill soils before hauling to the site. However, because of the potential variations within the borrow source, import soil will not prequalified by ESCSW. The imported fill should be placed in lifts no greater than 8 inches in loose thickness and compacted to at least 90% relative compaction (ASTM D 1557) near optimum moisture content. Shrinkage: The shrinkage factor for earthwork is expected to variably range from 15 to 30 percent for the upper excavated or scarified site soils. This estimate is based on compactive effort to achieve an average relative compaction of about 92% and may vary with contractor EARTH SYSTEMS CONSULTANTS SOUTHWEST August 8, 2000 - 13 - File No.: 07783-01 00-07-755 methods. Subsidence is estimated to range from 0.1 to 0.2 feet. Losses from site clearing and removal of existing site improvements may affect earthwork quantity calculations and should be considered. Site Drainage: Positive drainage should be maintained away from the structures (5% for 5 feet minimum) to prevent ponding and subsequent saturation of the foundation soils. Gutters and downspouts should be considered as a means to convey water away from foundations if adequate drainage is not provided. Drainage should be maintained for paved areas. Water should not pond on or near paved areas. 5.2 Excavations and Utility Trenches Excavations should be made in accordance with CalOSHA requirements. Our site exploration and knowledge of the general area indicates there is a potential for caving of site excavations (utilities, footings, etc.). Excavations within sandy soil should be kept moist, but not saturated, to reduce the potential of caving or sloughing. Where deep excavations over 4 feet deep are planned, lateral bracing or appropriate cut slopes of 1:1 (horizontal: vertical) should be provided. No surcharge loads from stockpiled soils or construction materials should be allowed within a horizontal distance measured from the top of the excavation slope, equal to the depth of the excavation. Utility Trenches: Backfill of utilities within road or public right-of-ways should be placed in conformance with the requirements of the governing agency (water district, public works department, etc.) Utility trench backfill within private property should be placed in conformance with the provisions of this report. In general, service lines extending inside of property may be backfilled with native soils compacted to a minimum of 90% relative compaction. Backfill operations should be observed and tested to monitor compliance with these recommendations. 5.3 Slope Stability of Graded Slopes J Unprotected, permanent graded slopes should not be steeper than 3:1 (horizontal: vertical) to reduce wind and rain erosion. Protected slopes with ground cover may be as steep as 2:1. However, maintenance with motorized equipment may not be possible at this inclination. Fill slopes should be overfilled and trimmed back to competent material. Slope stability calculations are not presented because of the expected minimal slope heights (less than 5 feet). EARTH SYSTEMS CONSULTANTS SOUTHWEST August 8, 2000 - 14 - File No.: 07783-01 00-07-755 STRUCTURES In our professional opinion, the structure foundation can be supported on shallow foundations bearing on a zone of properly prepared and compacted soils placed as recommended in Section 5.1. The recommendations that follow are based on very low expansion category soils in the upper two feet of subgrades. 5.4 Foundations Footing design of widths, depths, and reinforcing are the responsibility of the Structural Engineer, considering the structural loading and the geotechnical parameters given in this report. A minimum footing depth of 12 inches below lowest adjacent grade should be maintained. A representative of ESCSW should observe foundation excavations prior to placement of reinforcing steel or concrete. Any loose soil or construction debris should be removed from footing excavations prior to placement of concrete. _ Conventional Spread Foundations: Allowable soil bearing pressures are given below for foundations bearing on recompacted soils as described in Section 5.1. Allowable bearing pressures are net (weight of footing and soil surcharge may be neglected). ➢ Continuous wall foundations, 12-inch minimum width and 12 inches below grade: 1500 psf for dead plus design live loads Allowable increases of 300 psf per each foot of additional footing width and 300 psf for each additional 0.5 foot of footing depth may be used up to a maximum value of 3000 psf. ➢ Isolated pad foundations, 2 x 2 foot minimum in plan and 18 inches below grade: 2000 psf for dead plus design live loads Allowable increases of 200 psf per each foot of additional footing width and 400 psf for each additional 0.5 foot of footing depth may be used up to a maximum value of 3000 psf. A one-third (1/3) increase in the bearing pressure may be used when calculating resistance to wind or seismic loads. The allowable bearing values indicated are based on the anticipated maximum loads stated in Section 1.1 of this report. If the anticipated loads exceed these values, the geotechnical engineer must reevaluate the allowable bearing values and the grading requirements. Minimum reinforcement for continuous wall footings should be two, No. 4 steel reinforcing bars, placed near the top and the bottom of the footing. This reinforcing is not intended to supersede 1 any structural requirements provided by the structural engineer. Expected Settlement: Estimated total static settlement, based on footings founded on firm soils as recommended, should be less than 1 inch. Differential settlement between exterior and interior bearing members should be less than 3/4-inch. Frictional and Lateral Coefficients: Lateral loads may be resisted by soil friction on the base of foundations and by passive resistance of the soils acting on foundation walls. An allowable 1 coefficient of friction of 0.30 of dead load may be used. An allowable passive equivalent fluid pressure of 200 pcf may also be used. These values include a factor of safety of 1.5. Passive -1 EARTH SYSTEMS CONSULTANTS SOUTHWEST August 8, 2000 - 15 - File No.: 07783-01 00-07-755 resistance and frictional resistance may be used in combination if the friction coefficient is reduced to 0.20 of dead load forces. A one-third (1/3) increase in the passive pressure may be used when calculating resistance to wind or seismic loads. Lateral passive resistance is based on the assumption that any required backfill adjacent to foundations is properly compacted. 5.5 Slabs -on -Grade Subgrade: Concrete slabs -on -grade and flatwork should be supported by compacted soil placed in accordance with Section 5.1 of this report. Vapor Barrier: In areas of moisture sensitive floor coverings, an appropriate vapor barrier should be installed to reduce moisture transmission from the subgrade soil to the slab. For these areas an impermeable membrane (10-mil moisture barrier) should underlie the floor slabs.' The membrane should be covered with 2 inches of sand to help protect it during construction and to aide in concrete curing. The sand should be lightly moistened just prior to placing the concrete. Low -slump concrete should be used to help reduce the potential for concrete shrinkage. The effectiveness of the moisture barrier is dependent upon its quality, method of overlapping, its protection during construction, and the successful sealing of the barrier around utility lines. Slab thickness and reinforcement: Slab thickness and reinforcement of slab -on -grade are contingent on the recommendations of the structural engineer or architect and the expansion index of the supporting soil. Based upon our findings, a modulus of subgrade reaction of approximately 150 pounds per cubic inch can be used in concrete slab design for the expected very low expansion subgrade. Concrete slabs and flatwork should be a minimum of 4 inches thick. We suggest that the concrete slabs be reinforced with a minimum of No. 3 rebars at 18-inch centers, both horizontal directions, placed at slab mid -height to resist swell forces and cracking. Concrete floor slabs may either be monolithically placed with the foundations or doweled after footing placement. The thickness and reinforcing given are not intended to supersede any structural requirements provided by the structural engineer. The project architect or geotechnical engineer should continually observe all reinforcing steel in slabs during placement of concrete to check for proper location within the slab. Control Joints: Control joints should be provided in all concrete slabs -on -grade at a maximum spacing of 36 times the slab thickness (12 feet maximum on -center, each way) as recommended by American Concrete Institute (ACI) guidelines. All joints should form approximately square patterns to reduce the potential for randomly oriented, contraction cracks. Contraction joints in the slabs should be tooled at the time of the pour or saw cut (1/4 of slab depth) within 8 hours of concrete placement. Construction (cold) joints should consist of thickened butt joints with one- half inch dowels at 18-inches on center or a thickened keyed joint to resist vertical deflection at the joint. All construction joints in exterior flatwork should be sealed to prevent moisture or foreign material intrusion. These procedures will reduce the potential for randomly oriented cracks, but may not prevent them from occurring. Curing and QualiControl: The contractor should take precautions to reduce the potential of curling of slabs in this and desert region using proper batching, placement, and curing methods. EARTH SYSTEMS CONSULTANTS SOUTHWEST August 8, 2000 - 16 - File No.: 07783-01 00-07-755 1 Curing is highly effected by temperature, wind, and humidity. Quality control procedures may be used including trial batch mix designs, batch plant inspection, and on -site special inspection and testing. Typically, for this type of construction and using 2500-psi concrete, many of these quality control procedures are not required. 5.6 Retaining Walls The following table presents lateral earth pressures for use in retaining wall design. The values are given as equivalent fluid pressures without surcharge loads or hydrostatic pressure. Lateral Pressures and Sliding Resistance Granular Backfill Passive Pressure 300 pcf - level ground Active Pressure (cantilever walls) 35 pcf - level ground Able to rotate 0.1% of structure height At -Rest Pressure (restrained walls) 55 pcf - level ground Dynamic Lateral Earth Pressure Z Acting at mid height of structure, 25H psf Where H is height of backfill in feet Base Lateral Sliding Resistance Dead load x Coefficient of Friction: 0.40 Notes: 1. These values are ultimate values. A factor of safety of 1.5 should be used in stability analysis except for dynamic earth pressure where a factor of safety of 1.2 is acceptable. 2. Dynamic pressures are based on the Mononobe-Okabe 1929 method, additive to active earth pressure. Walls retaining less than 6 feet of soil need not consider this increased pressure. Upward sloping backfill or surcharge loads from nearby footings can create larger lateral pressures. Should any walls be considered for retaining sloped backfill or placed next to foundations, our office should be contacted for recommended design parameters. Surcharge loads should be considered if they exist within a zone between the face of the wall and a plane projected 45 degrees upward from the base of the wall. The increase in lateral earth pressure should be taken as 35% of the surcharge load within this zone. Retaining walls subjected to traffic loads should include a uniform surcharge load equivalent to at least 2 feet of native soil. Drainage: A backdrain or an equivalent system of backfill drainage should be incorporated into the retaining wall design. Our firm can provide construction details when the specific application is determined. Backfill immediately behind the retaining structure should be a free -draining granular material. Waterproofing should be according to the Architect's specifications. Water should not be allowed to pond near the top of the wall. To accomplish this, the final backfill grade should be such that all water is diverted away from the retaining wall. Backfill Compaction: Compaction on the retained side of the wall within a horizontal distance equal to one wall height should be performed by hand -operated or other lightweight compaction equipment. This is intended to reduce potential locked -in lateral pressures caused by compaction with heavy grading equipment. EARTH SYSTEMS CONSULTANTS SOUTHWEST �1I August 8, 2000 - 17 - 5.7 Mitigation of Soil Corrosivity on Concrete File No.: 07783-01 00-07-755 Selected chemical analyses for corrosivity were conducted on samples at the project site. The i native soils were found to have low sulfate ion concentration (to 0.08%) and high chloride ion concentration (to 0.13%). Sulfate ions can attack the cementitious material in concrete, causing weakening of the cement matrix and eventual deterioration by raveling. Chloride ions can cause corrosion of reinforcing steel. The Uniform Building Code does not require any special provisions for concrete for these low concentrations as tested. Normal concrete mixes may be used. A minimum concrete cover of three (3) inches should be provided around steel reinforcing or embedded components exposed to native soil or landscape water (to 18 inches above grade). Additionally, the concrete should be thoroughly vibrated during placement. Electrical resistivity testing of the soil suggests that the site soils may present a low potential for metal loss from electrochemical corrosion processes. Corrosion protection of steel can be achieved by using epoxy corrosion inhibitors, asphalt coatings, cathodic protection, or encapsulating with densely consolidated concrete. A qualified corrosion engineer should be consulted regarding mitigation of the corrosive effects of site soils on metals. 5.8 Seismic Design Criteria - This site is subject to strong ground shaking due to potential fault movements along the San Andreas and San Jacinto Faults. Engineered design and earthquake -resistant construction increase safety and allow development of seismic areas. The minimum seismic design should I comply with the latest edition of the Uniform Building Code for Seismic Zone 4 using the seismic coefficients given in Section 3.4.3 of this report. The UBC seismic coefficients are based on scientific knowledge, engineering judgment, and compromise. Factors that play an important role in dynamic structural performance are: (1) Effective peak acceleration (EPA), (2) Duration and predominant frequency of strong ground motion, (3) Period of motion of the structure, j (4) Soil -structure interaction, J (5) Total resistance capacity of the system, (6) Redundancies, (7) Inelastic load -deformation behavior, and (8) Modification of damping and effective period as structures behave inelastically. Factors 5 to 8 are included in the structural ductility factor (R) that is used in deriving a reduced value for design base shear. If further information on seismic design is needed, a site -specific probabilistic seismic analysis should be conducted. The intent of the UBC lateral force requirements is to provide a structural design that will resist collapse to provide reasonable life safety from a major earthquake, but may experience some structural and nonstructural damage. A fundamental tenet of seismic design is that inelastic EARTH SYSTEMS CONSULTANTS SOUTHWEST August 8, 2000 - 18 - File No.: 07783-01 00-07-755 yielding is allowed to adapt to the seismic demand on the structure. In other words, damage is allowed. The UBC lateral force requirements should be considered a minimum design. The owner and the designer should evaluate the level of risk and performance that is acceptable. Performance based criteria could be set in the design. The design engineer has the responsibility to interpret and adapt the principles of seismic behavior and design to each structure using experience and sound judgment. The design engineer should exercise special care so that all components of the design are all fully met with attention to providing a continuous load path. An adequate quality assurance and control program is urged during project construction to verify that the design plans and good construction practices are followed. This is especially important for sites lying close to the major seismic sources. 5.9 Pavements Since no traffic loading were provided by the design engineer or owner, we have assumed traffic loading for comparative evaluation. The design engineer or owner should decide the appropriate traffic conditions for the pavements. Maintenance of proper drainage is necessary to prolong the service life of the pavements. Water should not pond on or near paved areas. The following table provides our preliminary recommendations for pavement sections. PRELIMINARY PAVEMENTS SECTIONS R-Value Suhgrade Soils - 30 (assumed) Design Method — CALTRANS 1995 Flexible Pavements Rigid Pavements Asphaltic Aggregate Portland Aggregate Traffic Concrete Base Cement Base Index Pavement Use Thickness Thickness Concrete Thickness (Assumed) (Inches) (Inches) Inches (Inches) 4.0 Auto Parking Areas 2.5 4.0 4.0 4.0 5.0 Auto Driveways 3.0 6.0 5.0 4.0 6.0 Service Roads 3.5 8.0 6.0 5.0 7.0 Truck Access 4.0 10.0 7.0 6.0 Notes: 1. Asphaltic concrete should be Caltrans, Type B, 1/2-in. or 3/4-in. maximum -medium grading and compacted to a minimum of 95% of the 75-blow Marshall density (ASTM D 1559) or equivalent. ! 2. Aggregate base should be Caltrans Class 2 (3/4 in. maximum) and compacted to a minimum of 95% of ASTM D1557 maximum dry density near its optimum moisture. 3. All pavements should be placed on 12 inches of moisture -conditioned subgrade, compacted to a minimum of .90% of ASTM D 1557 maximum dry density near its optimum moisture. 4. Portland cement concrete should have a minimum of 3250 psi compressive strength @ 28 days. 5. Equivalent Standard Specifications for Public Works Construction (Greenbook) may be used instead of Caltrans specifications for asphaltic concrete and aggregate base. - ! 6. Clayey subgrades with R Values less than 30 will require additional 2 to 3 inches thickness of t aggregate base or underlain with a sand subbase (minimum R value 40). EARTH SYSTEMS CONSULTANTS SOUTHWEST August 8, 2000 - 19 - File No.: 07783-01 00-07-755 Section 6 LIMITATIONS AND ADDITIONAL SERVICES 6.1 Uniformity of Conditions and Limitations Our findings and recommendations in this report are based on selected points of field exploration, laboratory testing, and our understanding of the proposed project. Furthermore, our findings and recommendations are based on the assumption that soil conditions do not vary significantly from those found at specific exploratory locations. Variations in soil or groundwater conditions could exist between and beyond the exploration points. The nature and extent of these variations may not become evident until construction. Variations in soil or groundwater may require additional studies, consultation, and possible revisions to our recommendations. Findings of this report are valid as of the issued date of the report. However, changes in conditions of a property can occur with passage of time whether they are from natural processes or works of man on this or adjoining properties. In addition, changes in applicable standards occur whether they result from legislation or broadening of knowledge. Accordingly, findings of this report may be invalidated wholly or partially by changes outside our control. Therefore, this report is subject to review and should not be relied upon after a period of one year. In the event that any changes in the nature, design, or location of structures are planned, the conclusions and recommendations contained in this report shall not be considered valid unless the changes are reviewed and conclusions of this report are modified or verified in writing. This report is issued with the understanding that the owner, or the owner's representative, has the responsibility to bring the information and recommendations contained herein to the attention of the architect and engineers for the project so that they are incorporated into the plans and specifications for the project. The owner, or the owner's representative, also has the responsibility to take the necessary steps to see that the general contractor and all subcontractors follow such recommendations. It is further understood that the owner or the owner's representative is responsible for submittal of this report to the appropriate governing agencies. As the Geotechnical Engineer of Record for this project, Earth Systems Consultants Southwest (ESCSW) has striven to provide our services in accordance with generally accepted geotechnical engineering practices in this locality at this time. No warranty or guarantee is express or implied. This report was prepared for the exclusive use of the Client and the Client's authorized agents. ESCSW should be provided the opportunity for a general review of final design and specifications in order that earthwork and foundation recommendations may be properly interpreted and implemented in the design and specifications. If ESCSW is not accorded the privilege of making this recommended review, we can assume no responsibility for misinterpretation of our recommendations. Although available through ESCSW, the current scope of our services does not include an environmental assessment, or investigation for the presence or absence of wetlands, hazardous or toxic materials in the soil, surface water, groundwater or air on, below, or adjacent to the subject property. EARTH SYSTEMS CONSULTANTS SOUTHWEST August 8, 2000 - 20 - File No.: 07783-01 00-07-755 6.2 Additional Services This report is based on the assumption that an adequate program of client consultation, construction monitoring, and testing will be performed during the final design and construction phases to check compliance with these recommendations. Maintaining ESCSW as the geotechnical consultant from beginning to end of the project will provide continuity of services. The geotechnical engineering firm providing tests and observations shall assume the responsibility of Geotechnical Engineer of Record. Construction monitoring and testing would be additional services provided by our firm. The costs of these services are not included in our present fee arrangements, but can be obtained from our office. The recommended review, tests, and observations include, but are not necessarily limited to the following: • Consultation during the final design stages of the project. • Review of the building and grading plans to observe that recommendations of our report have been properly implemented into the design. • Observation and testing during site preparation, grading and placement of engineered fill as required by UBC Sections 1701 and 3317 or local grading ordinances. • Consultation as required during construction. •1• Appendices as cited are attached and complete this report. EARTH SYSTEMS CONSULTANTS SOUTHWEST August 8, 2000 - 21 - File No.: 07783-01 l 00-07-755 REFERENCES Abrahamson, N., and Shedlock, K., editors, 1997, Ground motion attenuation relationships: Seismological Research Letters, v. 68, no. 1, January 1997 special issue, 256 p. Blake, B.F., 1998a, FRISKSP v. 3.01b, A Computer Program for the Probabilistic Estimation of Peak Acceleration and Uniform Hazard Spectra Using 3-D Faults as Earthquake Sources, Users Manual, 191 p. Blake, B.F., 1998b, Preliminary Fault -Data for EQFAULT and FRISKSP, 71 p. ^} Boore, D.M., Joyner, W.B., and Fumal, T.E., 1993, Estimation of Response Spectra and Peak Accelerations from Western North American Earthquakes: An Interim Report; U.S. Geological Survey Open -File Report 93-509, 15 p. Boore, D.M., Joyner, W.B., and Fumal, T.E., 1994, Estimation of Response Spectra and Peak Acceleration from Western North American Earthquakes: An Interim Report, Part 2, U.S. Geological Survey Open -File Report 94-127. California Department of Conservation, Division of Mines and Geology: Guidelines for Evaluating and Mitigating Seismic Hazards in California, Special Publication 117, WWW Version. Envicom, Riverside County, 1976, Seismic Safety Element. Ellsworth, W.L., 1990, "Earthquake History, 1769-1989" in: The San Andreas Fault System, California: U.S. Geological Survey Professional Paper 1515, 283 p. Hart, E.W., 1994 rev., Fault -Rupture Hazard Zones in California: California Division of Mines and Geology Special Publication 42, 34 p. lkehara, M.E., Predmore, S.K., and Swope, D.J. (1996), Geodetic Network to Evaluate Historical Elevation Changes and to Monitor Land Subsidence in the Lower Coachella Valley, j U.S.G.S., Water Resources Investigation Report 97-4237 ll International Conference of Building Officials, 1997, Uniform Building Code, 1997 Edition. 1 International Conference of Building Officials, 2000, International Building Code, 2000 Edition. Jennings, C.W, 1994, Fault Activity Map of California and Adjacent Areas: California Division of Mines and Geology, Geological Data Map No. 6, scale 1:750,000. Joyner, W.B., and Boore, D.M., 1994, Prediction of Ground Motion in North America, in Proceedings of ATC-35 Seminar on New Developments in Earthquake Ground Motion Estimation and Implications for Engineering Design Practice, Applied Technology Council, 4 1994. EARTH SYSTEMS CONSULTANTS SOUTHWEST August 8, 2000 - 22 - File No.: 07783-01 - 00-07-755 Petersen, M.D., Bryant, W.A., Cramer, C.H., Cao, T., Reichle, M.S., Frankel, A.D., Leinkaemper, J.J., McCrory, P.A., and Schwarz, D.P., 1996, Probabilistic Seismic Hazard Assessment for the State of California: California Division of Mines and Geology Open -File Report 96-08, 59 p. Proctor, Richard J. (1968), Geology of the Desert Hot Springs - Upper Coachella Valley Area, California Division of Mines and Geology, DMG Special Report 94. Riverside County (1984), Seismic Safety Element of the Riverside County General Plan, Amended. Rogers, T.H., 1966, Geologic Map of California - Santa Ana Sheet, California Division of Mines and Geology Regional Map Series, scale 1:250,000. Seed, H.B. and Idriss, I.M., 1982, Ground Motions and Soil Liquefaction During Earthquakes. Sieh, K., Stuiver, M., and Brillinger, D., 1989, A More Precise Chronology of Earthquakes Produced by the San Andreas Fault in Southern California: Journal of Geophysical Research, Vol. 94, No. B1, January 10, 1989, pp. 603-623. Seih, Kerry, 1985, Earthquake Potentials Along The San Andreas Fault, Minutes of The National Earthquake Prediction Evaluation Council, March 29-30, 1985, USGS Open File Report 85-507. Structural Engineers Association of California (SEAOC), 1996, Recommended Lateral Force Requirements and Commentary. Tokimatsu, K, and Seed, H.B., 1987, Evaluation of Settlements in Sands Due To Earthquake Shaking, ASCE, Journal of Geotechnical Engineering, Vol. 113, No. 8, August 1987. Van de Kamp, P.C., 1973, Holocene Continental Sedimentation in the Salton Basin, California: A Reconnaissance, Geological Society of America, Vol. 84, March 1973. a Working Group on California Earthquake Probabilities, 1995, Seismic Hazards in Southern California: Probable Earthquakes, 1994-2024: Bulletin of the Seismological Society of JAmerica, Vol. 85, No. 2, pp. 379-439. Wallace, R. E., 1990, The San Andreas Fault System, California: U.S. Geological Survey JProfessional Paper 1515, 283 p. EARTH SYSTEMS CONSULTANTS SOUTHWEST APPENDIX A Figure 1- Site Location Map Figure 2 - Boring Location Map Table 1 Fault Parameters 1997 UBC Seismic Parameters 2000 IBC Seismic Parameters Logs of Borings . -, 0 f 7�2 ......... M wail, (0 Q (p -.77— Water Well, is r �ar•o,,.:ika Nk Z?) v L -Iij ---' 0. r —7!'r7� .40 113 % IL At 6p % La Quiv tal vp r n-1 F11 Reference: 7.5 min. La Quinta Figure 1 - Site Location USGS Quadrangle(photorevised 1980) Project Name: Embassy Suite Hotel Project No.:07783-01 Scale: 1 2,000' fie Earth Systems Consultants Southwest 0 2,000 4,000 �W)e uals'uGiX6YS`_ G IN2139 V(IIN3fAV ow C � O Nl O 9 C3 J y o N ti 'O top W yZ 0 N N we � 3 � O $ w a. i 3 W 0 r_ 0 cu U 0 J W im Z Q O W m J ca E X O L C. Q. O Suites Hotel 07783-01 Table 1 Fault Parameters & Deterministic Estimates of Mean Peak Ground Acceleration (PGA) Fault Name or Seismic Zone Distance from Site (mi) (km) Fault Type UBC Maximum Magnitude Mmax (Mw) Avg Slip Rate (mm/yr) Avg Return Period (yrs) Fault Length (km) Date of Last Rupture (year) Largest Historic Event >5.5M (year) Mean Site PGA (g) Reference Notes: (1) (2) (3) (4) (2) (2) (2) (5) (6) San Andreas - Coachella Valley 7.7 12.4 SS A 7.1 25 220 95 c. 1690 0.31 San Andreas - Southern (Cv+Sbm) 7.7 12.4 SS A 7.4 24 220 203 c. 1690 0.36 San Andreas - Mission Crk. Branch 7.9 12.7 SS A 7.1 25 220 95 6.5 1948 0.31 San Andreas - Banning Branch 7.9 12.8 SS A 7.1 10 220 98 6.2 1986 0.31 San Jacinto (Hot Spgs - Buck Ridge) 15 24 SS 0 6.5 2 354 70 6.3 1937 0.13 Blue Cut 16 26 SS C 6.8 1 760 30 -- 0.15 Burnt Mountain 19 30 SS B 6.4 0.6 5000 20 1992 7.3 1992 0.10 San Jacinto -Anza 19 31 SS A 7.2 12 250 90 1918 6.8 1918 0.16 San Jacinto - Coyote Creek 19 31 SS B 6.8 4 175 40 1968 6.5 1968 0.12 San Andreas - San Bernardino Mtn. 19 31 SS A 7.3 24 433 107 1812 7.0 1812 0.16 Eureka Peak 20 32 SS B 6.4 0.6 5000 19 1992 6.1 1992 0.09 Morongo 29 47 SS C 6.5 0.6 1170 23 5.5 1947 0.07 Pinto Mountain 31 50 SS B 7.0 2.5 500 73 0.09 Emerson So. - Copper Mtn. 34 54 SS B 6.9 0.6 5000 54 - 0.07 San Jacinto - Borrego Mountain 34 54 SS B 6.6 4 175 29 6.5 1942 0.06 Landers 34 55 SS B 7.3 0.6 5000 83 1992 7.3 1992 0.09 San Jacinto -San Jacinto Valley 35 57 SS B 6.9 12 83 42 6.8 1899 0.07 Pisgah -Bullion Mtn. -Mesquite Lk 36 58 SS B 7.0 0.6 5000 88 1999 7.1 1999 0.07 Earthquake Valley 38 61 SS B 6.5 2 351 20 0.05 Brawley Seismic Zone 41 67 SS B 6.4 25 24 42 5.9 1981 0.04 Elsinore - Julian 42 68 SS A 7.1 5 340 75 0.07 Johnson Valley (Northern) 45 72 SS B 6.7 0.6 5000 36 - 0.05 North Frontal Fault Zone (East) 45 73 DS B 6.7 0.5 1730 27 0.05 Elsinore - Temecula 46 74 SS B 6.8 5 240 42 0.05 Calico -Hidalgo 47 75 SS B 7.1 0.6 5000 95 0.06 Elmore Ranch 49 79 SS B 6.6 1 225 29 1987 5.9 1987 0.04 Elsinore -Coyote Mountain 50 80 SS B 6.8 4 625 38 0.04 Lenwood-Lockhart-Old Woman Spgs 50 81 SS B 7.3 0.6 5000 149 0.06 San Jacinto - Superstition Mountain 52 84 SS B 6.6 5 500 23 c. 1440 - 0.04 San Jacinto - Superstition Hills 53 86 SS B 6.6 4 250 22 1987 6.5 1987 0.04 North Frontal Fault Zone (West) 57 92 DS B 7.0 1 1310 50 0.05 Helendale - S. Lockhardt 58 93 SS B 7.1 0.6 5000 97 0.05 San Jacinto -San Bernardino 58 94 SS B 6.7 12 100 35 6.0 1923 0.03 Elsinore- Glen Ivy 60 97 SS B 6.8 5 340 38 6.0 1910 0.04 Weinert (Superstition Hills) 66 0 0 0 0.0 0 0 0 0.21 East Highline Canal (Sand Hills) 67 0 0 0 0.0 0 0 0 0.21 Imperial 68 0 0 0 0.0 0 0 0 0.21 Brawley 69 0 0 0 0.0 0 0 0 0.21 Elsinore - Laguna Salada 70 0 0 0 0.0 0 0 0 0.21 Noes: 1. Jennings (1994) and CDMG (1996) 2. CDMG & USGS (1996), SS = Strike -Slip, DS = Dip Slip 3. ICBO (1997), where Type A faults: Mmax > 7 and slip rate >5 mm/yr &Type C faults: Mmax <6.5 and slip rate < 2 mm/yr 4. CDMG (1996) based on Wells & Coppersmith (1994), Mw = moment magnitude 5. Modified from Ellsworth Catalog (1990) in USGS Professional Paper 1515 6. The estimates of the mean Site PGA are based on the following attenuation relationships: Average of: (1) 1997 Boore, Joyner & Fumal; (2) 1997 Sadigh et al; (3) 1997 Campbell (mean plus sigma values are about 1.6 times higher) Based on Site Coordinates: 33.681 N Latitude, 116.303 W Longtude and Site Soil Type D EARTH SYSTEMS CONSULTANTS SOUTHWEST �T i Project Name: Embassy Suites Hotel File No.: 07783-01 1997 UNIFORM BUILDING CODE (UBC) SEISMIC PARAMETERS Reference -] Seismic Zone: 4 Figure 16-2 }I Seismic Zone Factor: Z 0.4 Table 16-I Soil Profile Type: S D Table 16-J Seismic Source Type: A Table 16-U Closest Distance to Known Seismic Source: 12.4 km = 7.7 miles Near Source Factor: Na 1.00 Table 16-S Near Source Factor: Nv 1.10 Table 16-T Seismic Coefficient: Ca 0.44 = 0.44Na Table 16-Q Seismic Coefficient:: Cv 0.71 = 0.64Nv Table 16-R Closest Signficant Seismic Fault Source: San Andreas - Southern (Cv+Sbm) To: 0.13 sec Ts: 0.64 sec Seismic Importance Factor, I: 1.00 Table 16-K Period Sa 1997 UBC Equivalent Static Response Spectrum T (sec) (g) 0.00 0.44 1.2 f t 0.05 0.70 0.13 1.10 0.20 1.10 0.30 1.10 1.0 0.64 1.10 0.8 �! 0.70 1.01 - = s _ _ o 0.80 0.88 m 0.90 0.79 = E 1 0.6 1.00 0.71 f I 3 _ r U 1.10 0.64 Q 1.20 0.59 I I I 0.4 = 1.30 0.54 ff I: j .. k 1.40 0.50 CL cn 1.50 0.47 ' F _ 0.2 1.60 0.44 1.70 0.42 i 1.80 0.39 0.0 1.90 0.37 0.0 0.5 1.0 1.5 2.0 Period (sec) EARTH SYSTEMS CONSULTANTS SOUTHWEST Project Name: Embassy Suites Hotel File No.: 07783-01 2000 INTERNATIONAL BUILDING CODE (IBC) SEISMIC PARAMETERS Seismic Category D Table 1613.3(1) Site Class D Table 1615.1.1 Latitude: 33.681 N Longitude: -116.303 W Maximum Considered Earthquake (MCE) Ground Motion Short Period Spectral Reponse Ss 1.50 g Figure1615(3) 1 second Spectral Response SI 0.60 g Figure1615(4) Site Coefficient Fa 1.00 Table 1615.1.2(1) Site Coefficient FV 1.50 Table 1615.1.2(2) SMs 1.50 g = Fa*Ss SMI 0.90 g = Fv*SI Design Earthquake Ground Motion Short Period Spectral Reponse SDs 1.00 g = 2/3*SMs 1 second Spectral Response SDI 0.60 g = 2/3*Sm, To 0.12 sec = 0.2*SDI/SDs Ts 0.60 sec = SDI/SDs Seismic Importance Factor IE 1.00 Table 1604.5 Period Sa 2000 IBC Equivalent Elastic Static Response Spectrum 1 T (sec) (g) 0.00 0.40 1.2 I E 0.05 0.65 . _ _ 0.12 1.00 ` 1.0 0.30 1.00 f 0.60 1.00 ca 0.8 - = i 0.70 0.86 =} AD 0.80 0.75 ca = j 0.90 0.67 a7i 0.6 1.00 0.60 Q 1.10 0.55 1.20 0.50 m 0.4 - i 1.30 0.46 , a 1.40 0.43 J U) 1.50 0.40 0.2 1.60 0.38 1.70 0.35 1.80 0.33 0.0 1.90 0.32 0.0 0.5 1.0 1.5 2.0 2.00 0.30 Period (sec) 2.20 0.27 EARTH SYSTEMS CONSULTANTS SOUTHWEST Earth Systems Consultants Southwest 79-811B Country Club Drive, Bermuda Dunes, CA 92201 Phone f7601 345-1588 FAX (7601345-7315 Boring No: B1 Drilling Date: June 7, 2000 Project Name: Embassy Suites Drilling Method: 8" Hollow Stem Auger Project Number: 07783-01 Drill Type: Mobile B61 Boring Location: See Figure-2 Logged By: Clifford W. Batten ^ Sample Type Penetration y o Page 1 of 1 Description of Units Resistance 0 U Nate' The stratification Iines shown represent the Y x v A 5 02 approximate boundary between soil and/or rock types Graphic Trend A0 (Blows/6") A 0 and the transition may he gradational. Blow Count Dry Density 10 I� 15 20 25 i� 30 II 35 40 ,o 55 ML SANDY SILT: brown, laminated, medium dense to 15,18,20 87.9 2.6 dense, dry I16,20,30 90.2 2.3 MLCL CLAYEY SILT: brown, medium plasticity, hard, 16, 50 for 5" 85.6 5.8 damp SM SILTY SAND: brown, fine grained, medium dense, 10,7,15 88.5 1.2 dry MLCL CLAYEY SILT: brown, medium plasticity, hard, 20,21,25 76.1 7.9 damp 20,25,30 87.6 6.2 ML SILT: brown, laminated, medium dense to very 20,20,20 77.3 5.2 dense, damp, minor clay 21, 50 for 76.8 7.4 5" i 12,16,23 i 80.2 8.0 MLCL CLAYEY SILT: brown, medium plasticity, hard, 15, 50 for 5" 91.1 12.2 moist ML SANDY SILT: brown, laminated, very dense, Jdamp, 27, 50 for 73.3 9.1 minor clay 5" TOTAL DEPTH: 51.5 feet No Groundwater or Bedrock Encountered Earth Systems Consultants Southwest I 79-811B Country Club Drive, Bermuda Dunes, CA 92201 Phone (760) 345-1588 FAX(760) 345-7315 Boring No: B2 Drilling Date: June 7, 2000 Project arnc: Embassy Suites Drilling Method: 8" Hollow Stem Auger Project Number: 07783-01 Drill Type: Mobile B61 Boring Location: See Figure 2 Logged By: Clifford W. Batten ^ Sample Type Penetration .2;1 a3 � D@SCr1PtI0I1 Of Units :Page 1 of 1 Resistance A a Note: The stratification lines shown represent the Cn � a o - approximate boundary between soil and/or rock types Graphic Trend o (Blows/6") Q , and the transition may be gradational. Blow Count Dry Density to 0 ML SILT: brown, laminated, dense, damp, with minor . 18,23,40 86.0 10.2 sand and clay 5 16,21,23 85.0 4.9 1 - 10 • 15 - 20 - 25 - 30 - 35 - 40 - 45 - 50 - 55 SM SILTY SAND: -brown, medium grained, dense, dry 18,23,31 88.5 0.9 MIVCL CLAYEY SILT: brown, laminated, hard, damp 19,24,27 84.7 7.4 SM SILTY SAND: brown, medium grained, dense, dry 18,25,30 87.8 1.3 I ML SANDY SILT: brown, medium grained, dense, .20,22,24 84.2 4.0 damp ML SILT: brown, laminated, dense to very dense, damp, . 16,18,19 77.8 4.9 with minor clay .29, 50 for 76.5 6.0 5" MIICL CLAYEY SILT: brown, laminated, hard, moist .23, 50 for 79.6 10.8 5" ML SILT: brown, laminated, dense, damp 18, 50 for 77.2 5.3 5" CL CLAY: dark brown, medium plasticity, hard, damp .26, 50 for 5" TOTAL DEPTH: 51.5 feet No Groundwater or Bedrock Encountered Earth Systems Consultants Wr Southwest 79-811B Country Club Drive, Bermuda Dunes, CA 92201 Phone [7601 345-1588 FAX 060 345-7315 Borll NO: g3 Drilling Date: June 7, 2000 Project lame: Embassy Suites Drilling Method: 8" Hollow Stem Auger Project Number: 07783-01 Drill Type: Mobile B61 Boring Location: See Figure 2 Logged By: Clifford W. Batten ^ Sample Type Penetration �; v Pagel of 1 Description of Units P - Resistance ° I U � u A P. 'o Note: The stratification lines shown represent the Graphic Trend ca.A v approximate boundary between soil andlor rock types (Blowsl6') A 0 and the transition may be gradational. Blow Count Dry Density -0 -5 - 10 - 15 - 20 - 25 - 30 - 35 - 40 - 45 - 50 MUCL CLAYEY SILT: dark brown, medium plasticity, 15,20,20 177.6 2.0 hard, dry SM SILTY SAND: brown, medium grained, dense, dry 19,20,21 86.8 0.9 . 15,16,17 MUCL SM 85.1 9.0 CLAYEY SILT: brown, laminated, very stiff, damp SILTY SAND: brown, medium grained, dense, dry . 15,20,20 91.7 1.6 MUCL CLAYEY SILT: brown, laminated, very stiff to 20,30,35 78.8 12.3 hard, moist, with sand .15,17,20 77.0 7.4 16,20,30 V,1A 190.5 113.0 TOTAL DEPTH: 31.5 feet No Groundwater or Bedrock Encountered Earth Systems Consultants Southwest 79-81113 Country Club Drive, Bermuda Dunes, CA 92201 Phone (760) 345-1588 FAX (760) 345-7315 rl Boriq No: B4 Drilling Date: June 7, 2000 ProjectName: Embassy Suites Drilling Method: 8" Hallow Stem Auger Project Number: 07783-01 Drill Type: Mobile B61 Boring Location: See Figure 2 Logged By; Clifford W. Batten Sample Page 1 1 Type Penetration a� o of Description of Units Resistance U 5 Note: The stratification lines shown represent the A ¢ 'o approximate boundary between soil and/or rock types Graphic Trend A (B1ows16") A t j and the transition may be gradational. Blow Count Dry Density GO 10 ILI 20 25 30 35 40 45 50 L MVCL CLAYEY SILT: dark brown, medium plasticity, 14,19,21 87.0 1.3 hard, dry • 18,19,20 86.1 1.4 SM SILTY SAND: brown, medium grained, dense, dry 20,20,20 81.6 7.3 CLAYEY SILT: brown, laminated, medium dense, damp MLCL SM SILTY SAND: brown, medium grained, dense, dry 16,21,27 89.6 1.9 TOTAL DEPTH: 16.5 feet No Groundwater or Bedrock Encountered Earth Systems Consultants I'diff Southwest 79-811B Country Club Drive, Bermuda Dunes, CA 92201 Phone L760S 345-1588 FAX•(7601345-7315 1 Boring No: B5 Drilling Date: June 7, 2000 Project Name: Embassy Suites Drilling Method. 8" Hollow Stem Auger Project Number. 07783-01 Drill Type: Mobile B61 Boring Location: See Figure 2 Logged By. Clifford W. Batten Sample Page 1 of 1 Description Units ^_ Type Penetration of 1�" = Resistance _ U a�i y " Note: The stratification lines shown represent the p y U A p .o °= 0 approximate boundary between soil and/or rock types Graphic Trend Ap {Bbtivsl6"� � A and the transition may be gradational. Blow Count Dry Density 0 5 10 15 20 25 30 35 40 45 50 9,11,13 ML 91.6 1.2 SANDY SILT: brown, laminated, medium dense, dry MUCL CLAYEY SILT: dark brown, medium plasticity, 18,16,33 80.8 6.2 very stiff to hard, damp to moist 22,50 81.4 12.5 FOR 5" 37, 50 66.7 8.6 FOR 5" - TOTAL DEPTH: 16.5 feet No Groundwater or Bedrock Encountered I 0-- Earth Systems ConsultantsSouthwest 79-811B Country Club Drive, Bermuda Dunes, CA 92201 Pbone11601345-1588 FAX (750)345-7315 Boring No: B6 Drilling Date: June 7, 2000 Project Name: Embassy Suites Drilling Method: 8" Hollow Stem Auger Project Number: 07793-01 Drill Type: Mobile 63 Boring Location: Per Plan Logged By: Clifford W. Batten Sample Page 1 1 Type Pcnetrarion Description of Units of Resistance 0 co U n F v Note: The stratification lines shown represent the x v co ra ¢ .o 2 approximate boundary between soil and/or rock types Graphic Trend A o (BiowsJd") Q and the transition may be gradational. Blow Count Dry Density 0 5 ' 10 , 15 , 20 1 25 30 35 40 I 45 50 16,18,24 ML 73.9 4.1 SILT: brown, laminated, medium dense, dry ML/CL CLAYEY SILT: dark brown, medium plasticity, 21,20,18 i 82.2 14.5 very stiff to hard, dry 18,50 FOR 80.0 12.7 5" 27,30,45 83.2 11.6 TOTAL DEPTH: 16.5' FOOT No Groundwater or Bedrock Encountered Earth Systems Consultants Southwest 79-811B Country Club Drive, Bermuda Dunes, CA 92201 Phone (760) 345-1588 FAX (760) 345-7315 BorinNO: B7 Drilling Date: June 7, 2000 Project Name: Embassy Suites Drilling Method: 8" Hollow Stem Auger Project Number: 07783-01 Drill Type: Mobile B6I Boring Location: See Figure 2 Logged By: Clifford W. Batten Sample Type Penetration Y a� o Page 1 of 1 Description of Units v resistance U a 'o Note: The stratification lines shown represent the Y U I � A a approximate boundary between soil and/or rock types Graphic Trend Ao (Blowsl6") la U and the transitirnl maybe gradational. Blow Count Dry Density 10 i 15 20 25 30 35 F 40 J J 45 J L 50 ML SILT: brown, laminated,medium dense, dry to 7,9,10 damp, with clay and sand 8,11,13 7,8,21 6,7,11 8,11,14 TOTAL DEPTH: 21.5 feet No Groundwater or Bedrock Encountered i ■j Earth Systems Consultants Southwest 79-811B Country Club Drive, Bermuda Dunes, CA 92201 Phone (760) 345-1588 FAX {760} 345-7315 Boring No: BS Drilling Dale: June 7, 2000 Project Name: Embassy Suites Drilling Method: 8" Hollow Stem Auger Project Number: 07783-01 Dri[]Type: Mobile B61 Boring Location: See Figure 2 Logged By: Clifford W. Batten Sample Type Penetration Page 1 of 1 Description of Units Resistance _ U u represent Note: The stratification lines shown sent the y v rn A vR 'o — approximate boundary between sail and/or rock types Graphic Trend AFO- Ao (Blows16") A 0 and the transition may be gradational. Blow Count Dry Density 10 15 20 25 30 35 40 45 50 Earth Systems Consultants Southwest 79-811B Country Club Drive, Bermuda Dunes, CA 92201 Phone(760)345-1588 FAX [760]345-7315 Borin$9 Co:Name: Drilling Date: June 7, 2000 Project Embassy Suites Drilling Method: S" Hollow Stem Auger Project Number: 07783-01 Drill Type: Mobile B61 Boring Location: See Figure 2 Logged By: Clifford W. Batten Sample Type Penetration Description of Units Page 1 of 1 °= I Resistance U rr C. a Note: The stratification lines shown represent the v AO (Blawsl5") A o a approximate boundary between soil andlor rock types Graphic Trend Blow Count AA, A U and the transition may be gradational. Dry Density 10 15 20 25 30 35 40 45 50 APPENDIX B Laboratory Test Results UNIT DENSITIES AND MOISTURE CONTENT Job Name: Embassy Suites Hotel File Number: 07783-01 Date: 06/16/00 - 1 Sample Location Depth (feet) Unit Dry Density (pcf) Moisture Content (%) USCS Group Symbol B 1 2 87.9 2.6 ML 1 B 1 5 90.2 2.3 ML B 1 10 85.6 5.8 ML/CL -� B1 15 88.5 1.2 SM B 1 20 76.1 7.9 ML/CL B 1 25 87.6 6.2 MUCL B1 30 77.3 5.2 ML B1 35 76.8 7.4 ML 1 B 1 40 80.2 8.0 ML B 1 45 91.1 12.2 MUCL B 1 50 73.3 9.1 ML B2 2 86.0 10.2 ML B2 5 85.0 4.9 ML 1 B2 10 88.5 0.9 SM B2 15 84.7 7.4 MUCL 1 B2 20 87.8 1.3 SM B2 25 84.2 4.0 ML J B2 30 77.8 4.9 ML B2 35 76.5 6.0 ML B2 40 79.6 10.8 MUCL - ' B2 45 77.2 5.3 ML B3 2 77.6 2.0 ML/CL J B3 5 86.8 0.9 SM B3 10 85.1 9.0 ML/CL B3 15 91.7 1.6 SM UNIT DENSITIES AND MOISTURE CONTENT Job Name: Embassy Suites Hotel File Number: 07783-01 Date: 06/16/00 Unit Moisture USCS Sample Depth Dry Content Group Location (feet) Density (pcf) N Symbol B3 20 78.8 12.3 ML/CL B3 25 77.0 7.4 ML/CL B3 30 90.5 13.0 ML/CL B4 2 87.0 1.3 ML/CL B4 5 86.1 1.4 SM B4 10 81.6 7.3 ML/CL B4 15 89.6 1.9 SM B5 2 91.6 1.2 ML B5 5 80.8 6.2 ML/CL B5 10 81.4 12.5 ML/CL B5 15 66.7 8.6 ML/CL B6 2 73.9 4.1 ML B6 5 82.2 14.5 ML/CL B6 10 80.0 12.7 ML/CL B6 15 83.2 11.6 ML/CL 07783-01 Jun 16, 2000 PARTICLE SIZE ANALYSIS ASTM D-422 Job Name: Embassy Suites Hotel Sample ID: B1 @ 0-5 Feet Description: Sandy Silt with some clay (ML) Sieve Size % Passing 3" 100 2" 100 1-1/2" 100 1" 100 3/4" 100 1/2" 100 3/8" 100 #4 100 #8 100 #16 100 #30 99 #50 99 #100 88 #200 66 100 90 80 70 60 to w 50 0 40 30 20 10 0 By Hydrometer Method: Particle Size % Passing 45 Micron 54 19 Micron 37 11 Micron 31 6 Micron 22 4 Micron 18 3.1 Micron 15 2.5 Micron 15 1.3 Micron 10 % Gravel: 0 % Sand: 34 % Silt: 51 % Clay (3 micron): 15 100 10 1 0.1 Particle Size (mm) 0.01 0.001 EARTH SYSTEMS CONULTANTS SOUTHWEST 07783-01 Jun 16, 2000 PARTICLE SIZE ANALYSIS ASTM D-422 Job Name: Embassy Suites Hotel Sample ID: B1 @ 15' Feet Description: Very Silty Fine Sand (SM) Sieve Size % Passing By Hydrometer Method: 3" 100 Particle Size % Passing 2" 100 52 Micron 36 1-1/2" 100 20 Micron 27 1" 100 13 Micron 10 3/4" 100 7 Micron 8 1/2" 100 5 Micron 7 3/8" 100 3.3 Micron 5 #4 100 2.6 Micron 5 #8 100 1.4 Micron 4 #16 100 #30 100 % Gravel: 0 #50 100 % Sand: 60 #100 93 % Silt: 35 #200 40 % Clay (3 micron): 5 100 90 80 70 60 on Ei CwO a 50 . -- 0 40 30 20 10 0 100 10 1 0.1 0.01 0.001 Particle Size (mm) EARTH SYSTEMS CONULTANTS SOUTHWEST 07783-01 Jun 16, 2000 PARTICLE SIZE ANALYSIS ASTM D-422 Job Name: Embassy Suites Hotel Sample ID: B3 @ 5' Feet Description: Silty Fine Sand w/ Silt Layers (SM) Sieve Percent Size Passing 1-1/2" 100 1" 100 3/4" 100 1/2" 100 3/8" 100 #4 100 #8 100 #16 100 % Gravel: 0 #30 100 % Sand: 63 #50 98 % Silt: 30 #100 76 % Clay (3 micron): 7 #200 37 (Clay content by short hydrometer method) EARTH SYSTEMS CONSULTANTS SOUTHWEST 07783-01 PARTICLE SIZE ANALYSIS Job Name: Embassy Suites Hotel Sample ID: B6 @ 5' Feet Description: Clayey Silt (ML/CL) Sieve Size % Passing 3" 100 2" 100 1-1/2" 100 1" 100 3/4" 100 1/2" 100 3/8" 100 #4 100 #8 100 #16 100 #30 99 #50 99 #100 99 #200 97 100 90 80 70 60 bo a v 50 w 0 40 30 20 10 0 By Hydrometer Method: Particle Size % Passing 42 Micron 91 17 Micron 73 11 Micron 60 6 Micron 45 4 Micron 38 3.0 Micron 32 2.4 Micron 30 1.3 Micron 20 % Gravel: 0 % Sand: 3 % Silt: 67 % Clay (2 micron): 30 100 10 1 0.1 Particle Size (mm) Jun 16, 2000 ASTM D-422 0.01 0.001 EARTH SYSTEMS CONULTANTS SOUTHWEST 07783-01 PLASTICITY INDEX Job Name: Embassy Suites Hotel Sample ID: B3 @ 2' Feet Soil Description: Clayey Silt (ML/CL) Jun. 16, 2000 ASTM D-4318 DATA SUMMARY TEST RESULTS Number of Blows: 15 23 35 LIQUID LIMIT 33 Water Content, % 35.0 33.1 32.0 PLASTIC LIMIT 24 Plastic Limit: 23.9 24.3 PLASTICITY INDEX 9 35.5 ooR 35.0 34.5 34.0 p 33.5 U 33.0 +� 32.5 32.0 31.5 70 60 50 b 40 30 p" 20 10 0 10 Flow Index Number of Blows 100 Plasticity Chart Coil ML H H 0 10 20 30 40 50 60 70 80 90 100 Liquid Limit EARTH SYSTEMS CONSULTANTS SOUTHWEST 07783-01 Jun. 16, 2000 PLASTICITY INDEX ASTM D-4318 Job Name: Embassy Suites Hotel Sample ID: B4 @ 2' Feet Soil Description: Clayey Silt (ML/CL) DATA SUMMARY TEST RESULTS Number of Blows: 22 30 35 LIQUID LIMIT 36 Water Content, % 37.1 35.2 34.6 PLASTIC LIMIT 25 Plastic Limit: 24.7 24.8 PLASTICITY INDEX 11 Flow Index 37.5 0 37.0 36.5 � 36.0 - c�j 35.5 35.0 34.5 34.0 - 10 Number of Blows 100 70 60 k 50 b 40 30 y C� p" 20 10 0 Plasticity Chart CL ML 0 10 20 30 40 50 60 70 80 90 100 Liquid Limit EARTH SYSTEMS CONSULTANTS SOUTHWEST 07783-01 Jun. 16, 2000 PLASTICITY INDEX ASTM D-4318 Job Name: Embassy Suites Hotel Sample ID: B6 @ 5' Feet Soil Description: Clayey Silt (ML/CL) DATA SUMMARY TEST RESULTS Number of Blows: 35 29 17 LIQUID LIMIT 39 Water Content, % 37.1 38.1 41.0 PLASTIC LIMIT 26 Plastic Limit: 27.0 24.6 PLASTICITY INDEX 13 42.0 41.0 a� 40.0 p 39.0 U 38.0 37.0 36.0 70 60 50 d 40 jr 30 5 el p" 20 10 0 Flow Index 10 Plumber of Blows 100 0 Plasticity Chart Call H W 10 20 30 40 50 60 70 80 90 100 Liquid Limit EARTH SYSTEMS CONSULTANTS SOUTHWEST 07783-01 EXPANSION INDEX Job Name: Embassy Suites Hotel Sample ID: B1 @ 0-5' Feet Soil Description: Sandy Silt (ML) Initial Moisture, %: 11.8 initial Compacted Dry Density, pcf: 101.5 Initial Saturation, %: 49 Final Moisture, %: 22.3 Volumetric Swell, %: 1.0 Expansion Index: 10 Very Low Jun. 16, 2000 ASTM D-4829, UBC 18-2 EI UBC Classification 0-20 Very Low 21-50 Low 51-90 Medium 91-130 High 130+ Very High 07783-01 Jun. 16, 2000 CONSOLIDATION TEST ASTM D 2435-90 & D5333 Embassy Suites Hotel 131 @ 15' Feet Silty Fine Sand (SM) Ring Sample 2 1 0 -1 -2 -3 x c -4 Cd - ea 5 U -6 a� U it -7 a -8 -9 -10 -11 -12 Initial Dry Density: 86.6 pcf Initial Moisture, %: 1.2% Specific Gravity (assumed): 2.67 Initial Void Ratio: 0.925 Hydrocollapse: 1.7% @ 2.0 ksf % Change in Height vs Normal Presssure Diagram O Before Saturation ' Hydrocollapse ■ After Saturation OE Rebound Trend 0.1 1.0 Vertical Effective Stress, ksf 10.0 EARTH SYSTEMS CONSULTANTS SOUTHWEST 07783-01 Jun. 16, 2000 CONSOLIDATION TEST ASTM D 2435-90 & D5333 Embassy Suites Hotel Initial Dry Density: 85.8 pcf B3 @ 10 Feet Initial Moisture, %: 9.0% Clayey Silt (ML/CL) Specific Gravity (assumed): 2.67 Ring Sample Initial Void Ratio: 0.943 Hydrocollapse: 0.7% @ 2.0 ksf % Change in Height vs Normal Presssure Diagram O Before Saturation Hydrocollapse ■ After Saturation Rebound Trend 2 1 0 1 -8 -9 -10 -11 -12 0.1 1.0 Vertical Effective Stress, ksf 10.0 EARTH SYSTEMS CONSULTANTS SOUTHWEST 07783-01 Jun. 16, 2000 CONSOLIDATION TEST ASTM D 2435-90 & D5333 Embassy Suites Hotel Initial Dry Density: 89.8 pcf B5 @ 2 Feet Initial Moisture, %: 1.2% Very Sandy Silt (ML) Specific Gravity (assumed): 2.67 Ring Sample Initial Void Ratio: 0.857 Hydrocollapse: 1.1 % @ 2.0 ksf % Change in Height vs Normal Presssure Diagram O Before Saturation °Hydrocollapse ■ After Saturation Rebound Trend 2 1 0 -1 -2 -8 -9 -10 -11 -12 0.1 1.0 Vertical Effective Stress, ksf 10.0 EARTH SYSTEMS CONSULTANTS SOUTHWEST 07783-01 Jun 16, 2000 MAXIMUM DENSITY / OPTIMUM MOISTURE ASTM D 1557-91 (Modified) Job Name: Embassy Suites Hotel Sample ID: B 1 @ 0-5' feet Location: Native Description: Gray Brown, Sandy Silt (ML) Maximum Density: 113 pcf Optimum Moisture: 15.5% 140 I 135 .... .......,:e 130 ......., �., ... . 125 c� G. 120 a� A A 115 110 105 100 Procedure Used: A Prep. Method: Moist Rammer Type: Mechanical Sieve Size % Retained 3/4" 0.0 3/8" 0.0 #4 0.0 i <----- Zero Air Voids Lines, sg =2.65, 2,70, 2,75 i 0 5 10 15 20 25 Moisture Content, percent EARTH SYSTEMS CONSULTANTS SOUTHWEST ", 2 U) Jc O U) ul 4-1 rn H U cn 0 0 N 4' Ln i.a ai O 4-)A w ro ro r +-) }4 P O G. a -�1 (D >4 a) 9 rl fx 74 N o •a N E-+ U rn a�a 04 U) a E-1 >. z > 4 Ea E-1 Pc� 4-) a) U") as 0rn aD O A� w U) U I z ro N L45 O r- 'L3 I- UO a 4.3 E I H R7 I -rl 34 O O C rn :3 a) Lp U) ro I` V) M I, M A M CNJo z co [� N Ln 0 N M 0 0 m 0 NN ,-4 N 0 0 Ln rn �D 0 JOMMM.. .. co Ln a) I - - 1� O Ln N u u ul PO EO co 0 1 A t` t` 0 'O a) 43 u a) v s~ z° 0