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15599 (AC) Geotechnical Engineering Report & Addendum%k Earth Systems Consultants '�•� Southern Califomla RECEIVED APR 2 9 1995 April 27, 1995 KSL Recreation Corporation 56-140 PGA West Boulevard . La Quinta, California 92253 Project: Proposed Ballroom Addition La Quinta Resort and Club La Quinta, California Subject Geotechnical Engineering Report Addendum Busm Enghum s Divlslon 79-811B CountryCIub:Drive Bermuda Dunes,'CA 92201 (619) 345-1568 (619) 328-9131 FAX (619) 345-7315 B7-0271-PIA 95-04-745 Ref: Geotechnical Engineering Report prepared by Buena Engineers, Inc. dated December 9, 1987; Report No. 87-12-724 INTRODUCTION This addendum report -was prepared to . provide recommendations: for the design and - construction of the ballroom addition proposed for the La Quinta Resort and Club. It is our .understanding that :the ballroom -is proposed for an area. directly north of the existing: -hotel- facilities,: and- will `:include -a basement ---for subterranean parking. Preliminary. -._ design _:.information- provided -_by_.-the. _Structural .Engineer, Minuro_ Ikeda__. with Hillman. Biddison and Loevenguth indicates column - loads of up to ' 350 kips (including substantial live loads) and an anticipated footing depth of approximately fourteen (14) feet .below existing grade. The referenced Geotechnical Engineering Report was previously prepared by our firm for the design and construction of the existing hotel facilities to the south, east and west of . the proposed - ballroom site. Many of the recommendations included in the referenced report should be applicable to this project. The site of the proposed ballroom is located within the existing paved parking lot along the north end of the La Quinta Resort and Club property.. The parking area is fairly level, paved with asphalt and includes several landscape islands and decorative concrete walkways. There is a single story equipment building attached to the existing hotel that will also be directly adjacent to the proposed ballroom. FIELD EXPLORATION: Two (2) borings were excavated in the proposed building area to observe the soil profile and to obtain samples for further analysis. The borings were excavated to a maximum depth of approximately thirty-six (36) feet on April 5, 1995 using eight (8) inch diameter hollow stem augers powered by a CME 75 drilling rig. Samples were obtained within the borings with a two and one-half (2.5) inch inside diameter ring sampler (ASTM D 3550). The boring logs are attached and the approximate boring locations are indicated on the attached plan. April 27, 1995 -2- B7-0271-PIA 95.-04-745 LABORATORY TESTING: Samples were reviewed along with further analyzed. Those chosen representative of soils that would be the zone of influence of the proposed form and are attached. the field logs to determine which would be for laboratory analysis were considered encountered during grading or would be within structure. Test results are presented in graphic In -situ moisture content and unit dry weight for the ring samples were determined in general accordance with ASTM D 2937. The grain -size characteristics of selected samples were determined by sieve analysis and hydrometer procedures. Settlement and hydroconsolidation potential was evaluated from the results of consolidation tests performed in general accordance with ASTM D 2435. Maximum density - optimum moisture information and shear strength data were obtained from the referenced report based upon grain size correlation. SOIL CONDITIONS: As indicated by the borings, the site soils were found to consist primarily of silty very fine to fine grained -sands and -sandy clayey silts. The soils were found to be fairly loose throughout the upper twenty (20) feet with ring samples indicating relative compaction as low as seventy-eight (78) percent. The moisture content of the site soils varied from two (2) percent to over thirty-five (35) percent but in general, the silty fine sands were .moist and the clayey silts were wet. Consolidation testing indicates that the soils. encountered -near the `proposed foundation level may be susceptible to hydroconsolidation and compression related .settlements. The site w soils were - found to be very similar to those described in the referenced Geotechnical Engineering Report. SITE PREPARATION: Because our testing indicates that the soils encountered near the proposed foundation level (approximately:, _14 feet below .existing _ grade) .,may. be .susceptible to settlements; . we recommend overexcavation and recompaction of the bearing soils. In general, building areas should be overexcavated to a depth of at least five (5) feet below the bottom of the footings. The exposed surface should be scarified, moisture conditioned and recompacted to at least ninety (90) percent of maximum density. The previously removed soils should be replaced in thin lifts at near optimum moisture content and compacted to at least ninety (90) percent of maximum density. Overexcavation and compaction should be verified by testing. This applies to the building areas and at least five (5) feet beyond footing limits except adjacent to the existing equipment building which will be limited by the presence of the shoring and underpinning system. STRUCTURAL CONSIDERATIONS: An allowable bearing pressure of 3500 psf should be applicable for the design of structure foundations to be founded at the proposed basement foundation level. The allowable bearing pressures provided in the referenced report should be applicable for the design and construction of foundations to be constructed at grade for any auxiliary structures . These values are based upon dead plus reasonable live loads and can be increased by one-third for wind and seismic loading. EARTH SYSTEMS CONSULTANTS April 27, 1995 -3- B7-0271-PIA 95-04-745 The lateral values included in the referenced report remain applicable and are as follows; for "active" conditions an equivalent fluid pressure of 35 pcf is recommended for free -draining level backfill, for "at rest" or "restrained" conditions 55 pcf (EFP) is recommended for free -draining level backfill, for "passive" conditions 300 pcf (EFP) is recommended, a coefficient of friction of 0.49 is recommended but if combined with passive resistance the friction factor should be reduced to 0.33. Adequate basement wall drainage systems will be necessary to assure the "free draining" condition and prevent the buildup of hydrostatic pressures. SETTLEMENT CONSIDERATIONS: Based upon our recent and previous investigations and the assumption that the given recommendations will be. incorporated . into design and construction, we anticipate that settlements' will remain within the range included in the referenced Geotechnical Engineering Report. We anticipate total settlements of less than one (1) inch and differential settlements of less than one-half (.1/2) inch. The majority of the settlements should occur during- construction. GEOLOGIC AND SEISMIC CONSIDERATIONS: The geologic and seismic hazards outlined in - the referenced Geotechnical Engineering Report should be considered in design. There are no active or potentially active faults on the . site but due to the proximity of active faults, strong ground motion should be anticipated during the life of the proposed development. It is recommended that the structure be, designed .by a qualified professional. who is aware of the project site's seismic setting. The potential for other seismic hazards such as liquefaction occurring at the site is negligible. SPECIAL UNDERPINNING AND SHORING CONSIDERATIONS: Because the proposed ballroom is to be constructed directly adjacent to the equipment room for the existing hotel building, underpinning and shoring will be necessary during basement excavation. A preliminary plan submitted by Mr. Ikeda indicating a drilled pier/soldier. . pile support and shoring system appears to be an appropriate underpinning. method for this project. The following structural values should be applicable for underpinning and shoring system design. The "active" pressures indicated above should be applicable for estimating lateral pressures for shoring design but surcharge loading from the existing equipment room foundations should also be considered. In the case of isolated drilled pile foundations. the previously recommended "passive" resistance (300 pcf EFP) can be double. However, the maximum passive resistance should be 5000 psf. A minimum pile spacing of six (6) feet is recommended to maintain maximum lateral capacity for the individual piles. Because the foundation loading of the existing equipment room should be fairly light, we anticipate that lateral capacity will control pile design. A minimum pile depth of twenty (20) feet is recommended for adequate axial capacity but we anticipate deeper piles to accommodate lateral loading. The additional depth of the recommended overexcavation should be considered in pile design. We recommend a minimum drilled pile diameter of two (2) feet to provide room for proper positioning of the "H" pile within the drilled hole and beneath the existing foundation. EARTH SYSTEMS CONSULTANTS ,April 27, 1995 -4- B7-0271-P1A 95-04-745 If there are any questions concerning this report or the referenced report, please contact the undersigned. Respectfully submitted, EARTH SYSTEMS CONSULTANTS O Q�FE 'Y y~ �� Brett L. Anderson, P. Copies: 4/KSL Recreation Corporation/Greg Burkhart 2/Hillman, Biddison & Loevenguth/Minuro Ikeda 1/VTA File o EARTH SYSTEMS CONSULTANTS R P Ti 1110 1 •• ` I, '' I'•- t I M-1 1,'!•li.� - i.��.�lyl'! j;,Q 'i2r•: �J: 1 ' s Pr ed: i �I i •� ' �� a k •. Ballroom` a...° .0 ;;I 1 . ,... ! ..} t .. 1• Existing Hotei Buildings :.. �i' ,� i I :. r• .. ..._ i �_ ..✓jai s'.i '- I ilJtil�i Y 1. ..L•1, 1 .!•+..-1. i 1•. r 1 .t . -. -. -."-1 Approximate Boring Location La Quinta Hotel Expansion . Date: 4/5/95 Location: Per Plan BORING NO. 1 File No. B7-0271-P1A 0 E 0 3 DESCRIPTION 0 o _ 0 0 C > C REMARKS 0 :� •C U 75 O o U 0 B1: Brown clayey very, ML 5 1/2" A.C. over 5° Base sandy silt " 37 106.5 14.3 96 5 - 24 Al Brown clayey silty sM 117.0 11.1 100 Interbedded B1 layers - very fine to fine sand " B1: Brown clayey'very ML 10 30 sandy silt 96.2 16.0 87 - A 1 :Brown clayey silty sM - very fine to fine sand 15 47 97.2 2.0 83 20 - 23 B2: Brown very fine sandy ML 94.3- 24.5 , 86 " ' - clayey silt -2.5 ,. _ 30 B1: Brown clayey. very ML 93.7. 4.7- 784. "Interbedded Al layers _ sandy silt 30 _ 50/10" �� �� �� 97.3 9.3 88 Interbedded B2 layers _ B2: Brown very fine sandy ML 35 clayey silt 21 99.6 21.8 90 - - Relatively undisturbed Total Depth = 36' - ring sample No Free Water - No Bedrock 40 ® No recovery 45 _ Note: The stratification _ lines represent the approximate boundaries _ between the soil types; the 50 transitions may be gradual. La Quinta Hotel Expansion Date: 4/5/95 Location: Per Plan BORING NO. 2 File No. 67-0271-PIA a E o N DESCRIPTION �' N .o c Cis REMARKS c T o 0 0 Z� g ; U 0 B 1 : Brown clayey very ML 5" A.C. over 5" Base - sandy silt 48 108.4 10.7 98 5 - 25 A 1 :Brown clayey silty SM 96.9 16.6 82 - very fine to fine sand 10 40 u o u 1.5 T. 37 VT 2.0 - 30 B2: Brown very fine sandy ML 86.1 35.7 78 - clayey silt . i5 _ 47 A 1 :Brown clayey silty - SM 105:.1 18.9- :.8.9 Abundant:intetbedded. _ very fine to fine sand B1 layers 30 50 u u u 91.6 11.5 78 so _ B2: Brown very fine sandy ML 35 31 clayey silt 83.6 33.0 76 - - Relatively undisturbed Total Depth = 36' - ring sample No Free Water No Bedrock 40 ® No recovery 45 Note: The stratification _ lines represent the _ approximate boundaries _ between the soil types; the 50 transitions may be gradual. Pressure in KIPS per Square Foot 0.5 1.0 2.0 4.0 8.0 .03 .02 .01 EEIE 0.0 7z .0 U .� .01 U a f: .02 ::;;;EfFec 17 Gig G €er= .03 .02 .01 0.0 ,C U .01 a� a .02 U Q L: c .03 0 C, b 0 04 m 0 U .05 .06 .07 .08 .09 .10 Pressure in KIPS per Square Foot 0.5 1.0 2.0 _ _ $ HEET ==4z _ _ _ 4.0 7T� C z - n - — - - _ --ate E E EN _ _ _ - C 8.0 Pressure in KIPS per Square Foot 0.5 1.0 2.0 4.0 8.0 .03 .02 .01 0.0 v .01 H d a 00 .02 U C. act=oE f". A Pressure in KIPS per Square Foot 0.5 1.0 2.0 4.0 8.0 .03 .02 .01 0.0 z z z z 4 .01 a� a co .02 U C. 0 .03 cis X0, 0 a 0 04 U .05 -SN17r .06 .07 08 .09 .10 Consolidation Diagram La Quinta Hotel Expansion Boring 2 @ 20' EARTH SYSTEMS CONSULTANTS Date: 4/27/95 1 Job No.: B7-0271-PIA Pressure in KIPS per Square Foot 0.5 1.0 2.0 4.0 8.0 .03 .02 .01 EEIE 0.0 .� .01 to N tL .02 a a a 0 .03 b 0 0 .04 m c U 05 .0s .07 .08 .09 .10 Consolidation Diagram nta Hotel Expansion ring 2 �+ 25' EEARTH TEMS CONSULTANTS 5 Job No.: B7-0271-PIA - — - - — - — - - afar= - — - Re�uand: x = - - RECEIVED APR 281995 GEOTECHNICAL ENGINEERING REPORT LA QUINTA HOTEL EXPANSION LA QUINTA, CALIFORNIA PREPARED FOR LANDMARK LAND COMPANY, INC. B7-0271-P1 DECEMBER 9, 1987 BUENA ENGINEERS, INC. �' Buena Engineers, Inc. AN EARTH SYSTEMS. INC. COMPANY Z% December 9, 1987 Landmark Land Company, Inc. P. 0. Box 1000 La Quinta, CA 92253 Project: La Quinta Hotel Expansion La Quinta, CA Subject: Geotechnical Engineering Report B7-0271-P1 87-12-724 Presented herewith is our Geotechnical Engineering Report prepared for'the proposed hotel expansion to be located adjacent to the existing La Quinta Hotel in La Quinta, California. This report incorporates the tentative information supplied to our- office, and in accordance with the request, recommendations for general site development,and foundation design are provided. This report completes our scope of services in accordance with our agreement dated November 9, 1987. Other services which 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. Please contact the undersigned if there are any questions concerning this report or the recommendations included herein. Respectfully submitted, Buena Engineers, Inc. R. Layne Richins Staff Geologist Reviewed and Ap ��k K 061-t- YJoseph R. Venuti Civil Engineer RLR/JRV/'mea 'Copies: 2 - Landmark Land Company, Inc. 2 - J. F. Davidson VENTURA Attn: Lloyd Watson (805) 642-6727 2 - PS file 2 - VTA file OQRurtSs��,� y�rN OIF G No. C-- Exo. kJ'Jq �` cpw`�%�: LANCASTER (805) 948-7538 BAKERSFIELD SANTA BARBARA BERMUDA DUNES SAN LUIS OBISPO (805) 327-5150 (805) 966-9912 (619) 345-1588 (805) 544-6187 TABLE OF CONTENTS NTRODUCT I ON...........................................:.......:....:............................ 1 PURPOSE AND SCOPE OF WORK ......................................................... 1 SITEDESCRIPTION............................................................................. 2. FIELD EXPLORATION........................................................................... 3 LABORATORY TESTING....................................................................... 4 SOILCONDITIONS............................................................................... 4 GROUNDWATER..........................................................:................:........ 5 REGIONAL GEOLOGY............................................................................ 5 LOCAL GEOLOGY ........ ........................ ................:...................... GEOLOGICHAZARDS........................................................................... 6 Primary...................................................................................... 6 Secondary.................................................................................... 7 CONCLUSIONS AND DISCUSSIONS..................................................... 8 RECOMMENDATIONS..................... :...................... ................................. 8 SITE DEVELOPMENT AND GRADING .................................................... 9 Site Development - Grading9 Site Development - General.......................................................... 1 1 Excavations.................................................................................. 14 TrafficAreas............................................................................... 14 Ut-i 1 i ty Trenches........................................................................... 14 STRUCTURES........................................................................................ 15 Foundations.................................................................................. 15 Slabon Grade............................................................................... 17 Settlement Considerations.......................................................... 17 Frictional and Lateral Coefficients ............................................. 18 Slope'Stabi l ity............................................................................ 18 Expansion..................................................................................... 18 Additional Services..................................................................... 19 LIMITATIONS AND UNIFORMITY OF CONDITIONS ............................. 19 REFERENCES ......................... ......... 21 ...................................................... APPENDIX A Site and Vicinity Map Logs of Borings APPENDIX B Summary of Test Results Table 29-A APPENDIX C Standard Grading Specifications BUENA ENGINEERS, INC. December 9, 1987 �� - 87-0271-P1 87-12-724 This Geotechnical Engineering Report has been prepared for the proposed expansion of the existing La Quinta Hotel in La Quinta, California. The expansion will include a ballroom, hotel facilities, an auxiliary building, service buildings and condominiums. A. The ballroom will be of steel frame construction. The expected loading is as follows: Continuous footings - one thousand two hundred (1200) pounds per linear foot, Column loads fourty-five (45) kips, double column loads - ninety (90) kips, maximum column load at midspan portico - two hundred sixty-four (264) kips. B. The expected loading for the hotel facilities is as follows: Continuous footings - one thousand one hundred (1100) pounds per linear foot for single story buildings and three thousand (3000) pounds per linear foot for two (2) story buildings. C. The expected loading for the auxiliary buildings is as follows: Continuous footings two thousand five hundred (2500) pounds per linear. foot. D. •The condominiums will be of wood frame and stucco construction. The expected loading is as follows: continuous footings --one thousand -twenty (1020) pounds per linear foot for single story and one thousand -three hundred (1300) pounds per linear foot for two (2) story buildings. E. The expected loading as outlined above was provided by Alejandro Martinez of Landmark -Land Company, Inc. F. All loading is assumed to be dead plus reasonable live load. The purpose of our services was to evaluate the site soil conditions, and to provide conclusions and recommendations relative to the site and the proposed development., The scope of work includes the following: A. A general reconnaissance of the site. B. Shallow subsurface exploration by drilling. BUENA ENGINEERS, INC. December 9, 1987 -2- 137-0271-P 1 87-12-724 C. Laboratory testing of selected soil samples obtained from the exploratory borings drilled for this project. D. Review of selected technical literature pertaining to the site. E. Evaluation of field and laboratory data relative to soil conditions. F. 'Engineering analysis of the data obtained from the exploration and .testing programs, G. A summary of our findings and recommendations in written report. Contained in this report are: A. Discussions onregional and local geologic and soil conditions. B. Graphic and/or tabulated results of laboratory tests and field studies. C. Discussions and recommendations relative to allowable foundation bearing capacity, recommendations for foundation design, estimated total and differential settlements, lateral earth pressures and site grading criteria. The site of the proposed project is located west of Eisenhower Drive and north of the existing La Quinta Hotel in the La Quinta area of Riverside County, California. A. There are existing buildings on a portion of the site which will be demolished prior to construction. The remaining area is vacant with scattered short grass and debris. B. The property is basically level throughout with a slight overall slope to the east. C. There appears to have been some minor grading previously performed on the site. D. There is undoubtly underground utilities throughout the site, particularly in the area of the existing buildings. BUENA ENGINEERS, INC. a December 9, 1987 -3- 137-0271-P 1 87-12-724 E. Septic systems and dry wells were found in the area of the proposed auxiliary building and it is likely they may be found in other areas also. FIELD EXPLORATION Exploratory borings were drilled for observing the soil profile and obtaining samples for further analysis. A. Nine (9) borings were drilled for soil profiling and sampling to a maximum depth of fourty-one (41) feet below the existing ground surface. Borings were drilled on November 9 and November 10, -1987, using an eight,(8) inch diameter hollow -stem auger powered by a CME 45-B drilling rig. The approximate boring locations. as indicated on the attached plan in Appendix A, were determined by pacing and sighting from existing streets and topographic features. The boring locations should -be considered accurate only to the degree implied by the method used. B. Samples were secured within the borings with a two and one-half (2.5) inch diameter ring sampler (ASTM D 3550, shoe similar to ASTM D 1586). The samples were obtained by driving the sampler with a one hundred forty (140) pound hammer, dropping thirty (30) Inches. The number of blows required to drive the sampler one foot was recorded. Recovered soil samples were sealed in containers and returned to the laboratory for further classification. and testing. C. Bulk disturbed samples of the soils were obtained from cuttings developed during excavation, of the test borings. The. bulk samples were secured for classification purposes and represent a mixture of soils within the noted depths. D. The final logs represent our interpretation of the contents of the field logs, and the results of the laboratory observations and tests of the field samples. The final logs are included in the appendix A of this report. The stratification lines represent the approximate boundaries between soil types although the transitions may be gradual. BUENA ENGINEERS, INC. December 9, 1987 -47 B7-0271-P 1 87-12-724 After a visual and tactile classification in the field, samples were returned to the laboratory, classifications were checked, and a testing program was established. A. Samples were reviewed along with field logs to determine which would be further analyzed. Those chosen were considered as representative of soil which would be exposed and/or used in grading and those deemed within building influence. B. In -situ moisture content and unit dry weights for the core samples were developed in accordance with ASTM D 2937, C. The relative strength characteristics of the subsurface soils were determined from the results of direct shear tests. Specimens were placed in contact with water at least twenty-four (24) hours before .testing, and were then sheared under normal loads ranging from 0.5 to 2.0 KSF. D. Settlement and hydroconsolidation potential was evaluated from the results of consolidation tests performed in accordance with ASTM D 2435. E. Classification tests consisted oT Expansion Index. W13C Standard No. 29-2), Maximum Density -Optimum Moisture (ASTM D 1557), and Hydrometer Analysis (California Test Method 203). F. Refer to Appendix B for tabular and graphic representation of the test results. SOIL CONDITIONS As determined by the borings, site soils were found to consist primarily of interbedded sands and silts.. The boring logs -in Appendix A contain a more detailed description of the soils encountered. A. Soils were found to be quite loose with the majority of the in -place densities being well below ninety (90) percent of maximum density with many in the seventy (70) percent range. B. The soils were found to be fairly dry in the upper ten (10) to fifteen (15) feet. BUENA ENGINEERS, INC. December 9, 1987 -5- 137-0271-P 1 87-12-724 C. Clay and slit contents of the soils exhibit low plasticity. Expansion tests indicate soils to be in the "low" expansion. category in accordance with Table 29-A in Appendix B of this. report. Refer to section F of the structures section for specific explanations and requirements dealing with expansive soil D. Soils should be readily cut by normal grading equipment Free groundwater was not encountered at the time of drilling. Groundwater levels in the vicinity of the site are generally greater than one hundred ten (1 10) feet below -the existing surface. Fluctuations in groundwater levels may occur due to variations in rainfall, temperature and other factors. The project site is located in the western Coachella Valley at the base of the Santa 'Rosa Mountains, east of Indio Mountain. The Coachella Valley is part of the tectonicaliy active Salton Basin. This basin i's a closed, internally draining trough that has been filled .with a complex series of continental clastic materials during Pleistocene and Holocene time (Van de Camp, 1973). The San Andreas rift zone dominates the geology of the Coachella Valley.' The Banning and Mission Creek faults,. which are parts of the San Andreas system are responsible for earthquakes recently felt in the Coachella, Valley. Other regional faults that have produced events felt in.the Coachella Val.ley are the San Jacinto, Imperial and Elsinore faults (see figures 1 & 2).. La Quinta is known as one, of the "Cove" communities and is situated on an alluvial wedge between two (2) granite mountain spurs. The project area was at one (1) time covered by the waters of ancient Lake Cahuil la. Principal geologic units encountered on site are Quaternary Lake deposits and alluvial sediments. Acolian deposits are also found in the vicinity of the subject property. BUENA ENGINEERS, INC. December 9, 1987 A. Primary Seismic Hazards: -6— B7-0271 -P 1 87-12-724 Primary seismic geologic hazards that may affect any property in the seismically active southern California region include ground rupture and strong ground motion. a. The project site is not located in any Alquist-Priolo special study zones. Nor are any faults mapped through or adjacent to the project area. At the time of drilling no surface expression of faulting was observed. b. Fault rupture would most likely occur .along previously established traces. However, fault rupture may --occur at other locations not previously mapped. 2. Ground Shaking a. Strong ground motion is the seismic hazard most likely .to affect the site during the life of the intended structures. Using methods developed by Seed and Idris (1982) the following table was compiled for anticipated accelerations which may be experienced during an earthquake at the project site. Design* fault arth uake San Andreas 7.5 San Jacinto 6.5 * Richter Magnitude TABLE 1 Estimated Maximum Maximum Repeatable Approximate Acceleration Acceleration Ground Distance to in Rock ia-Soil Accelerations - Project Site • 45g 22g .33g .18g .21 g .12g BUENA ENGINEERS, INC. B .'Lone Pine- 0\\ y 1 • 1946 (6-2) oCAino Lok< Bokerslielo, Q \ 1 " IS52(7.7,6.4,6.1,6.1) °Baker /.!ojave 1947(6 2) _=•- °Son: a N. or/o ISt6 (6) o .% earslaw rmcn \ _ \ \ Porn. rcntoR-41 cro Bole. � (6.0) Y �\S� ; 1925 63) � 1971 (6.4) °Son Ben^cr ino___ Los C,-.gele IS48 (6.5'r `\ErJin�. 192 S 1918 (6.8; c� Indio° Rivar,�de Co. 1933 (6.3) l"Ott o 1968(6.4) Ecrr�go j� row/ty 194 1940(6.7`• 0 1915 (6'/4 , 6'/< � r-o Son Q.•'e90 — "urr 0 /00 /rules 0 /000 ?00 Kris. Earth Quakes of magnitude,5.9 and greater in the Southern California Region, 1912 — 1972 (including the North Palm Springs Earthquake). From Hileman et al (1973) 1934(6. 1a34 (7.1 1915 (7.1) J 1 1935(6.0) Enseneoo . 195 ( 6.8,6.1, 6.3.6.4 ) v 1954(6.36.0) r 1 of scot-er-a California regicz ;-it`s major faults BUENA ENGINEERS, INC. e^an et a (1973) i"aiece D.l7E: 12-03-87 FILE ►:0. B7-0271-P1 In December 9, 1987 -7- 137-0271-1)1 87-12-724 b. Because of the lacustrian sedimentary nature of the soils on site, ground shaking characteristics are expected to include low frequency vibration with relatively high amplitudes. Duration of shaking could be from ten (10) to thirty (30) seconds. The La Quinta area is mapped in ground shaking zone III B (Alluvium of intermediate thickness) as designated by the County of Riverside, California. B. Secondary Seismic -Geologic Hazards; Secondary seismic geologic hazards that may affect the project site area include liquefaction, ground lurching and subsidence. a. Subsidence, whether seismically related or not, is considered a potential hazard in this area. Historic records report significant .episodes of subsidence In the La Quinta area due to seismic forces and heavy rain fall and flooding. b. Liquefaction is -the loss of soil strength as a result of an increase in poor water pressure due to cyclic seismic loading. Conditions for liquefaction include relatively high water table (within 40' of surface), low relative densities of the saturated soils and susceptibility of the soil to liquefy based on grain size. Our -research indicates water is at depths greater than ninety (90) feet below the surface. Also, the project 'is not located in the Riverside County liquefaction study zone. C. Ground lurching is generally associated with fault rupture. Because of the sites distance from any known "active" faults, the possibility of ground lurching affecting the site is considered low C. Geologic Hazards (Non-Selsmlc): Other geologic hazards that could affect the project site include landslides, flooding and erosion. a. No evidence of past landsliding was observed at the site nor are any known landslides mapped in, or around the project site. the subject property is not at the immediate base of any steep hills and is located on relatively flat ground. BUENA ENGINEERS, INC. December 9, 1987 -8- 87-0271-13 1 87-12-724 b. Flooding and erosion are always a consideration in and regions. CONCLUSIONS AND DISCUSSIONS Based on a review of a selected technical literature and site investigations, it is our opinion that, the site is suitable for the intended development -provided they are designed around the noted geologic hazards. The following is a summary of our conclusions and professional opinions based on the data obtained. Recompaction of soil will be required to limit settlement and improve bearing capacity. A. The primary geologic hazard. relative to site development is severe ground shaking from earthquakes originating on nearby faults. The site is located in Southern California which is an active seismic area. In our opinion, a major seismic event originating on either the San Andreas or San Jacinto fault zones would be the most likely cause of significant earthquake actvity at the site within the estimated design life of the proposed development. B. Settlement due to seismicfactors or flooding is a potential hazard in the La Quinta area. C. Areas'of alluvial sails may be susceptible to erosion. Preventative measures to minimize seasonal flooding and erosion should be incorporated into site grading. D. Other hazards including liquefaction, landslides and tsunamis are considered negligible. RECOMMENDATIONS Based on our Interpretation of the data obtained and our understanding of. the proposed construction, the following recommendations are provided and represent professional opinions. It is recommended that any permanent structure constructed on the sites be designed to at least minimum requirements for Seismic Zone 4 based on the latest edition of the Uniform Building Code. BUENA ENGINEERS, INC. December 9, 1987 -9- 137-0271-P 1 87-12-724 2. Adherence to the following grading recommendations is necessary to mitigate potential settlement problems due to seismic forces, heavy rainfall and flooding: SITE DEVELOPMENT AND GRADING Prior to any construction operations, areas to be graded should be cleaned of vegetation and other deleterious materials. Appendix C, "Standard Grading Specifications" contains specific suggestions for removal and disposal of deleterious substances and, as such, forms a part of these Site Development and Grading Recommendations. A. Site Development -.Grading Site grading should be visually checked.by Buena Engineers, Inc., or their representative prior to placement of fill. Local variations in soil conditions may warrant increasing the depth of recompaction and/or overexcavation to control differential settlement and to produce a more uniform bearing condition, foundations should bear on compacted soils. Compaction is to be verified by testing. 1. Condominiums Building areas should be overexcavated to a depth of two (2) feet below original grade or two (2) feet below the bottom of the footings, whichever is greater. The exposed surface should be scarified, moisture conditioned and recompacted so that a minimum of ninety (90) percent of maximum density is obtained. If desired, an additional foot may be removed in lieu of processing and recompacting the bottom. The previously removed soil and/or fill material should then be placed in eight (8) inch layers in a loose condition at or near optimum moisture and compacted to a minimum of ninety (90) percent of maximum density. The intent is to have three (3) feet of soil compacted to a minimum of ninety (90) percent of maximum density compose the building pad beneath the footings. BUENA ENGINEERS, INC. December 9, 1987 -10- ■e .fie :.. : � �� a. Single Story Hotel Facilities B7-0271-P1 87-12-724 The building areas for the single story hotel facilities should be prepared as.described above for condominiums b. Auxiliary Building and Two -Story Hotel Facilities Building areas should be over -excavated to a depth of three (3) feet below original grade or three (3) feet below the bottom of the footings, whichever is greater. The exposed surface should be scarified, moisture conditioned and recompacted so that a minimum of ninety (90) percent of maximum density is obtained. If desired, an additional foot may be removed in lieu of processing and recompacting the bottom. The previously removed soil and/or fill material should then be placed in eight inch layers in a loose condition at or near optimum moisture and compacted to a minimum of ninety (90) percent of maximum density. The intent is to have four (4) feet of soil compacted to a minimum of ninety (90) perce-nt of maximum density compose the building pad beneath the footings. a. The building area with the exception of the area of high loading (mid -span portico column) should be overexcavated to a depth of five (5) feet below original grade of the bottom of the footings, whichever is greater.. The exposed surface should be scarified, moisture conditioned and recompacted so that a minimum of ninety (90) percent of maximum density is obtained. It desired, an additional foot may be removed in lieu of processing and recompacting the bottom. The previously removed- soil and/or fill material should then be placed in eight (8) inch layers in a loose condition at or near optimum moisture and compacted to a minimum of ninety (90) percent of maximum density. The intent is to have six (6) feet of soil compacted to a minimum of ninety (90) percent of maximum density compose the building pad beneath the footings. BUENA ENGINEERS, INC. December 9, 1987 B7-0271-P1 87-12-724 b. The area of the midspan portico column with the expected loading of two hundred -sixty four (264) kips should be overexcavated to a depth of nine (9) feet below original grade or the bottom of the footings, whichever is greater. The exposed surface should be scarified, moisture conditioned and recompacted to a minimum of ninety (90) percent of maximum density. If desired, an additional foot can be removed in lieu of processing and recompacting the bottom. The previously removed soil and/or fill material should then be placed as previously described. The intent is .to have ten (10) feet of soil compacted to a minimum of ninety (90) percent of maximum density compose the building pad beneath the footing. 4. Because there are existing buildings on the site which will be removed prior to the construction of the proposed buildings, proper demolition is imperative. Any footings, utilities, -septic systems, etc., found in building areas must be removed and any resulting depressions which fall below the overexcavati-on depth must be backfilled and compacted to a minimum of ninety M) percent of maximum density. No compacted fill should be placed unless the underlying soil has been observedby Buena Engineers, Inc. 5. These grading requirements apply to building areas and at least five (5) feet beyond building or footing limits. B. Site Development - General The existing ground surface should be initially prepared for structures by removing vegetation, weeds, noncomplying fill or other incompetent material. Roots should be extracted and pickers used to remove oversized roots from fill soils. Depressions resulting from these removals should have debris and loose soil removed and be filled with suitable fill soils adequately compacted. No compacted fill should be placed unless the underlying soil has been observed by Buena Eng i neers, i nc. BUENA ENGINEERS, INC. December 9, 1987 -12- B7-0271-P I 87-12-724 2; In order, to he-lp minimize .potential settlement problems associated with structures supported on a non -uniform thickness of compacted fill, Buena Engineers, Inc. should be consulted for site grading recommendations relative to backfilling large and/or deep depressions resulting from removal under item one above. In general, all proposed . construction should be supported by a uniform thickness of compacted soil. 3. Testing showed that in -place densiti-es are fairly low and that the soils are very dry. Soils of this type can be susceptible to consolidation when water is added at the in -situ conditions. Therefore, recompaction of the bearing soils is recommended, 4. Previously removed soils, once cleaned of rocks larger than eight (8) inches in greatest dimension, and other deleterious material, may be placed M thin layers and mechanically compacted back to finish grade. 5. Import soil used to raise site grades should `be equal to or better than on -site soil in strength, expansion, and compressibility characteristics. Import soil may be prequalified by Buena Engineers, Inc. Comments on the characteristics of import will be given after the material is on the project, either in -place or In stockpiles of adequate quantity to complete the project. 6. Fill and backfill should be compacted to the minimum of ninety (90) percent of maximum dry density obtained by the ASTM D 1557 test method. Our "Standard Grading Specification," contained in Appendix C of this report, and Chapter 70 of the Uniform Building Code contain specific considerations for grading and form a part of this report. 7. It is anticipated that during grading a loss of approximately one tenth (1) of a foot due to stripping, and a shrinkage factor of about fifteen (15) to twenty (20) percent for the upper three (3) feet of soil may be used for quantity calculations. This is based on compactive effort needed to produce an average degree of compaction of approximately. ninety three (93) to ninety four (94) percent, and may vary depending on contractor methods. Subsidence is estimated between two - tenths (2) to three -tenths (3) of a foot. BUENA ENGINEERS, INC. December 9, 1987 -13- B7-0271-P 1 87-12-724 8. Areas around the structures should be graded so that .drainage is positive and away from the structures. Gutters and down spouts should be used to convey water out of the foundation area. Water should not be allowed to pond on or near pavement sections. 9. Added moisture within previously compacted fill could result in a number of reactions at the surface depending upon the amount of moisture increase, the in -place density of the soil, in -situ moisture content and soil type. Although the soil could in reality be expanding, collapsing, moving laterally due to the phenomenon "creep", the result is usually movement and will most likely manifest itself visually in structural slabs and street areas as cracks, (lateral and horizontal displacement), heaving of slabs etc. 10. The obvious cure to the problem is to not introduce excess moisture into fill material once in place. To help minimize increased moisture into the fill material, site drainage and landscape is critical. Site drainage should be in the form of roof gutter, concrete brow ditcher, ribbon gutters and gutters, storm drain and other drainage devices. -Landscaping should be such that water is not allowed to pond. Additionally, care should be taken -so -as not to over water landscaped areas. 11. Failure to control increase in moisture content to compacted fill could result in settlement which could compound the problem by rupturing water lines or other services and/or utilities, thus introducing additional moisture into the underlying soi I. 12. The Recommended Grading Specifications included in Appendix C are general guidelines only and should not be included directly into project specifications without first incorporating the site specific recommendations contained in the soil engineering report. Chapter 70 of the Uniform Building Code contains specific considerations for grading .and is considered a part of these. recommendations. BUENA ENGINEERS, INC. December 9, 1987 -14- 137-0271-P 1 87-12-724 13. It is recommended that Buena Engineers, Inc., be retained to provide soil engineering services during construction of the grading, excavation, and foundation phases of the work. This is to observe compliance with the design concepts, specifications or recommendations and to allow design changes in the event that subsurface conditions differ from those anticipated prior to start of construction. C. Excavations 1. All excavations should be made in accordance with applicable regulations. From our site exploration and knowledge of general area, we feel there is a potential for construction problems involving caving of relatively deep site excavations (i.e. utilities, etc.) Where such situations are encountered, lateral bracing or appropriate cut slopes should be provided. 2. No surcharge loads should be allowed within a horizontal distance measured from the top of the excavation slope, equal to the depth of the excavation. D. Traf f i c Areas During rough grading streets should be provided with two (2) feet of subgrade compacted to ninety (90) percent of maximum density. 2. On -site parking should be provided with two (2) feet of subgrade compacted to ninety (90) percent of maximum density. 3. Final preparation of subgrade will depend on paving section designs. E. Utility Trenches Backfill of utilities within road right-of-way should be placed in strict conformance with the requirements of the governing agency (Water District, Road Department, etc.) BUENA ENGINEERS, INC. December 9, 1987 -1 S- B7-0271-P 1 87-12-724 2. -Utility trench backfill within private property should be placed in strict provisions of this report relating to minimum compaction standards. In general, service lines extending inside of property, may be backfilled with native soils compacted to a minimum of ninety (90) percent of maximum density. 3. Backfill operations should be observed and tested by Buena Engineers, Inc., to monitor compliance with these recommendations. STRUCTURES' Based upon the results of this evaluation, it is our opinion that structure foundation can be supported by compacted soils placed as recommended above., The recomendations that follow are based on "low" expansion category soils. A. foundations It is anticipated that foundations will be placed on firm compacted soils as recommended else -here in this report. The recommendations that follow are based on "low" expansion category soils. 1. Table 29-A gives specific recommendations for width, depth and reinforcing. Other structural consideration may be more stringent and would govern in any. case. A minimum footing depth of twelve (12) inches below lowest adjacent finish grade for one (1) story structures and eighteen (18) inches for two .(2) story structures should be maintained. 2. Conventional foundations: Estimated bearing values are given below for foundations *on recompacted soils, assuming fill import (if required) to be equal to or better than site soils: BUENA ENGINEERS, INC. December 9, 1987 -16- 137-0271-P 1 87-12-724 a. Continuous foundations of one (1) foot wide and twelve (12) inches below grade: i. 1200 psf for dead plus reasonable live loads. ii. 1600 psf for wind and seismic considerations. b. Isolated pad foundations 2' x 2' and bottomed twelve (12) inches below grade: 1. 1500 psf for dead plus reasonable live loads. 11. 2000 psf for wind and seismic considerations. 3. Allowable increases of 250 psf per one (i) foot of additional footing width and 300 psf for each additional six (6) inches of footing depth may be used. The maximum allowable bearing will be 3500 pcf. . 4. . The footing reinforcement required per Table 29=A; is one (1) number four (4) rebar at top and bottom of footings. Other requirements that are more stringent due to structural loads will govern. 5. Soils beneath footings and slabs should be premoistened prior to placing concrete. 6. Lateral loads may be resisted by soil friction on floor slabs and foundations and by passive resistance of the soils acting on foundation stem walls. Lateral capacity is based partially on the assumption that any required backfiil adjacent to foundations and grade beams is'properly compacted. 7. Foundation excavations should be visually observed by Buena Engineers, Inc., during excavation and prior .to placement of reinforcing steel or concrete. Local variations in conditions may warrant deepening of footings. 8. Allowable bearing values are net (weight of footing and soil surcharge may be neglected) and are applicable for dead plus reasonable live loads. BUENA ENGINEERS, INC. "v December 9, 1987 -17- 137-0271-P i 87-12-724 B. Slabs -on -Grade 1. Concrete slabs -on -grade should be supported by compacted structural fill placed in accordance with applicable sections of this report. 2. In areas of moisture sensitive floor coverings, an appropriate vapor barrier should be, installed in order to minimize vapor transmission from the subgrade soil to the slab. The membrane should be covered with two (2) inches of sand to help protect it during construction. The sand should be lightly moistened just prior to placing the concrete. 3. Reinforcement of slab -on -grade is contingent upon the structural engineers recommendations and the expansion index of the supporting soil. Since the mixing of fill soil with native soil could change the expansion index, additional tests should be conducted during rough grading to determine the expansion index of the subgrade soil. Also due to the high temperature differential endemic to desert areas, large concrete slabs on grade are susceptible to tension cracks. Reinforcing required per table 29-A is 6" x 6" / * 10 x 010 welded wire fabric. Additional reinforcement due to the expansion index of the site soil should be provided as recommended in section F below. Additional reinforcement may also be required by the structural engineer. 4. It is recommended that the proposed perimeter slabs (sidewalks, patios, etc.) be designed relatively independent of foundation stems (free-floating) to help mitigate. cracking due to foundation settlement and/or expansion. 1. Maximum estimated settlement, based on footings founded on firm soils as recommended, should be less than one (1) inch. Differential settlement between exterior and interior bearing members should be less than one-half 0 /2) inch. 2. The majority of settlement should occur during construction. BUENA ENGINEERS, INC. r December 9, 1987 -18- 137-0271-P 1 87-12-724 D. Frictional and Lateral Coefficients 1. Resistance to lateral loading may be provided by friction acting on the base of foundations, a coefficient of friction of .49 may be used for dead load forces. 2. Passive resistance acting on the sides of foundation stems (300 pcf, equivalent fluid weight), may be included for resistance to lateral load. 3. A one-third (1 /3) increase in t-he quoted passive value may be used for wind or seismic loads. 4. Passive resistance of ,soils against grade beams and the frictional resistance between the floor slabs and the supporting soils may be combined in determining the total - lateral resistance, however the . friction factor should be reduced to .33 of dead load forces. 5. For retaining walls backfilled with compacted native soil, it is recommended that an equivalent fluid pressure of thirty-five (35) pcf be used for well drained level backfill conditions. Slope stability calculations were not performed due to the anticipated minimal slope height (less that 5') if slopes exceed five t5) feet, engineering calculations should be performed to substantiate the stability of slopes steeper than 2 to 1. Fill slopes should be overfilled and trimmed back to competent material. f. fxoansion The design of foundations should be based on the weighted expansion index (UBC Standard No. 29-2) of the soil. As stated in the soil properties section, the expansion index of the on -site soil is in the low (21-50) classification. However, during site preparation, if the soil is throughly mixed and additional fill .is added, the expansion index may change. Therefore, the expansion index should be evaluated after the site preparation has been completed, and the final foundation design adjusted accordingly. BUENA ENGINEERS, INC. B7-0271-P1 87-12-724 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 Buena Engineers, Inc., as the soil engineering firm from beginning to end of the project will help assure continuity of services. These test would be additional services provided by our firm. The costs of these services are not included in our present fee arrangements. The recommended tests and observations include, but are not necessarily limited to the following: 1. Consultation during the final design stages of the project. 2. Review of -the building plans to observe that recommendations of our report have been properly implemented into the design. 3. Observation and testing during site preparation, grading and placement of engineered fill. 4. Consultation as required during construction. The analysis and recommendations submitted in this report are based in part upon the data obtained from the nine (9) borings performed on the site. The nature and extent of variations between the borings may not become evident until construction. If variations then appear evident, it will be. necessary to reevaluate the recommendations of this report. Findings of this report are valid as of this date; however, changes in conditions of a property can occur with passage of time whether they be due to natural processes or works of man on this or adjacent properties. In addition, changes in applicable or appropriate 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. .BUENA ENGINEERS, INC. December 9, 1987 -20- 137-0271-P 1 87-12-724 In the event that any changes 1n the nature, design or location of the building 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 modified or verified in. writing. This report is issued with the understanding that it is the responsibility of the owner, or of his representative to insure that the information and recommendations contained herein are called .to the attention of the architect and engineers for the project and Incorporated into the plan and that the necessary steps are taken to see that the contractor and subcontractors carry out such recommendations in the field. Buena Engineers, Inc.; has prepared this report for the exclusive use of the client and authorized agents. This report has been prepared in accordance with generally accepted soil and foundation engineering practices. No other warranties, either expressed or Implied, are made as the professional advice provided under the terms -of this agreement, and included in the report. It is recommended that Buena Engineers, Inc., -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 Buena Engineers, Inc., is not accorded the privilege of making this recommended review, we can assume no responsibility for misinterpretation of our fecommendations). END OF TEXT Appendices BUENA ENGINEERS, INC. December 9, 1987 -21- 137-0271-P1 87-12-724 1. Envicom, Riverside County, 1975, Seismic Safety Element. 2. Greensfelder, Roger W., 1974, :Maximum Credible Rock Accelerations from Earthquakes in California, CDMG Map Sheet 23. 3. Ploessel, M. R. and Slosson, J. E., "Repeatable High Ground Accelerations from Earthquakes", 1974 California Geology, Vol. 27, No. 9, Pgs. 195-199. 4. 'Seed, H. B. and Idriss, I. M., 1982) Ground Motions and Soil Liquefaction wring Earthquakes. 5. Seih, Kerry, 1985, "-Earthquake Potentials Along The San Andreas Fault", Minutes of The National. Earthquake Prediction Evaluation Council, March 29-30, 1.985, USGS Open file Report 85-507. BUENA ENGINEERS, INC. APPENDIX A Site and Vicinity Map Logs of Borings BUENA ENGINEERS, INC. !rj l - C) di 7 -..::2 % 1 i j L .... 44 11 H, 1111 if! pc V rl U TFU77MTPTf-l. TH T. o' iWHIM! ft! i! 1:11-I "I "I 1!;! 1 if 1.1 130,&Ve. 4.cw_'.4770A15 *K---7-', 77' LOG OF BORING Job No. B7-0271-P1 for Report No. LA OUINTA HOTEL EXPANSION DATE 11-09-87 BORING NO. '2 LOCATION Per Plan s 0. U C] 0 o' E 9, `n, L O V) 3 O to DESCRIPTION �. �w c H L O U S. ~ .. cn c O ? r3 � n. L ° u 0L U REMARKS AND ANALYSIS 34. 35 �7 25 B1: Light Brown clayey very fine sandy silt. 96.9 88.7 3.4 4.5 ML 87 80 5 Al: Light brown silty very fine sand. 89.5 2.9 SM 82 10 B1: Light brown clayey very fine sandy silt. ML 15 Al: Light brown silty very fine sand. NOTE: The stratification lines represent the approximate boundaries between soil types and the actual tran- sitions may be gradual. Relatively Undisturbed ring sample. Total 0epth = 16' No free water encountered. a as tc W DATE 11-09-87 LOG OF BORING for LA QUINTA HOTEL EXPANSION BORING NO. 3 Job No. B7-0271—P1 Report No. LOCATION Per Plan --. w. v n. U 0 o >,o. V) "L. U o . co DESCRIPTION *' .� �� c►.v 5 6 Q • 41 41 � L ou :E 0~ � F' V) c o 5 C E .L u0U C� U Pt . REMARKS AND ANALYSIS 14 13 15 16 20 14 32 B1: Light brown clayey very fine sandy silt. 99.4 98.2 95.3 21.1 17.0 22.9 ML ML ML 89 88 86 5 Al: Light brown silty very fine sand. 98.7 96.0 6.6 5.0 SM' SM 90 88 10 15 20 Cl: Grey brown very fine silty clay. 88_3 32.5 CL 80 25 Al: Light brown silty very fine sand. 99.7. 13.6 SM 9i NOTE: The stratification lines represent the approximate boundaries between the soil types and the transitions may be gradual. Relatively undisturbed ring sample. Terminated drilling = 26' No free water encountered. i 1G LC U DATE 11-09-87 LOG OF BORING for LA OUINTA HOTEL EXPANSION BORING NO. 4 Job No. B7-0271—P1 Report No. LOCATION Per Plan . ,. r o o E, L 3 o . DESCRIPTION 1 �� U L p U H o > 5 c L REMARKS AND ANALYSIS 24 20 25 31 35 25 35 17 25 B1: Light brown clayey very fine sandy silt 94.7 4.0 ML 85 5 1 Al: Light brown silty very fine sand. 94.1 88.2 87.4 3.3 10.5 8.2 SM SM SM 86 79 80 10 15 20 C1: Grey brown very fine _ sandy silty clay. 86:6 15.5 CL 79 Al: Light brown silty very fine sand. 101.2 6.4 SM 93 �5 Cl: Grey Brown very fine sandy silty clay. 93.8 89.0 84.2 6.5 24.4 25.3 CL CL CL 85 81 77 30 35 40 — NOTE: The stratification lines represent the approximate boundaries between the soil types and the transitions may be gradual. Relatively Undisturbed ring sample. Terminated drilling = 41, No free water. rialC D LOG OF BORING for LA OUINTA HOTEL EXPANSION BORING NO. 5 Job No. B7r0271—Pi Report No. . LOCATION Per Plan .-. n io 0 E `r' L N 3 ea DESCRIPTION 3 .� w Q a L n, F. V) c 0 U +� a - L C U 0- REMARKS AND ANALYSIS , • • B1: Light brown clayey very fine sandy silt. 91.3 3.0 ML 84 Al: Light brown silty very- fine..sand. 96.2 91.3 74.5 2.5 3.2 3.4 SM SM Sri 88 84 68 5 10 15 20 Cl: Grey brown very fine - sandy silty clay. 86.2 90.8 85.9 22.1 22.7 30.2 CL CL CL 78 83 78 25 30 35 0 NOTE: The stratification lines represent the approximate boundaries between soil types and the tranditions may be gradual. Relatively Undisturbed rinn sam le. Terminated drilling = 41' No free water encountered. LOG OF BORING Job No. B7-0271-P1 for Report No. LA OUINTA HOTEL EXPANSION < .. DATE 11-10-87 BORING NO. 6 LOCATION Per Plan s �. o 0 o �� .L 3 d DESCRIPTION `' �oQ D C) , � L i� ° F' Ln c p > a .E L �Uc REMARKS AND ANALYSIS 26 B1: Light brown clayey very fine sandy silt. 82.2 3.2 ML 74 Y33 00 24 31 Al: Light brown silty very fine --sand. 92.5 93.6 2.0 2.0 SM 85 85 5 10 Bl: Light brown clayey very fine sandy silt. 79.8 5.0 72 15 NOTE: The stratification lines represent the approximate boundaties between soil types and the actual tran- sitions may be gradual. Relatively Undisturbed ring sample. Total Depth = 16' No free water encountered. DATE 11-10-87 LOG OF BORING for -LA QUINTA HOTEL EXPANSION BORING NO. 7 Job No. B7-0271-P1 Report No. LOCATION Per Plan ,-. 41 s o o 0 o E N L y 3 d DESCRIPTION *' 1 �„� �o a u h L i& �. t ° c • o .? � L �U�. REMARKS AND ANALYSIS 20 �3 �7 24 81: Light brown clayey very fine sandy silt. 95.9 2.4 ML 86 5 Al: Light.brown silty very fine sand SM B1: Light brown clayey very fine'sandy silt. 87,5 8.0 79 10 Al: Light brown silty very fine sand. 79.8 3.4 83 15 NOTE: The stratification lines represent the approximate boundaries between soil types and the actual tran- sitions may be gradual. Relatively Undisturbed ring sample. No recovery. Total Depth = 16' No free water encountered. LOG OF BORING Job No. B7-0271-P1 for Report No. DATE 11-10-87 LA OUINTA HOTEL EXPANSION BORING NO. 8 LOCATION Per Plan -� .c 41 o C� 0 0 �% L N 3 co DESCRIPTION " � �; C) n. u y L :E Q.V) F' c 0 ? ra i U REMARKS AND ANALYSIS B1: Light brown clayey very fine sandy silt. ML 37 37 19 19 31 Al: light brown silty very fine sand. 80.4 94.4 86.4 A 1.5 5.9 SM 82 86 79 B1 in end about 2" thick 5 10 15 Cl: Grey brown very silty clay. 84.8 25.6 CL -- 20 NOTE: The stratification lines represent approximate boundaries between soil types and the actual transitions may be gradual. Relatively undisturbed ring sample. No recovery. Total Depth = 21' No free water encountered. DATE 11-10-87 LOG OF BORING for LA OUINTA HOTEL EXPANSION BORING NO. 9 Job No. B7-0271—P1 Report No. LOCATION Per Plan .0 n, U 0 o to .L, 0 h 3 0 DESCRIPTION .� �^ C L U H L O U �"' v) o ? ra E L V 0 IV�p�° CUB REMARKS AND ANALYSIS 01 14 I 61: As previous ML Al: Light brown silty very fine sand. 98.5 4.2 SM 90 5 10 15 NOTE: The stratification lines represent the approximate boundaries between soil types and the acctual transitions may be gradual. Relatively undisturbed ring sample. Total Depth = 15' No free water encountered. R11 a aa►c u APPENDIX B Summary of Test Results Table 29-A BUENA ENGINEERS, INC. r � December 9, 1987. me BORING/DEPTH 1 @ 1-5' 7@ 0-2' USCS ML ML SOIL DESIGNATION B 1 B 1 Ck Pt MAXIMUM DENSITY (pcf) 1 1 1.1 117.5 OPTIMUM MOISTURE 153 13.1 ANGLE OF I NT. FR I C. 31.0 --- COHESION (psf) 141 --- EXPANSION INDEX 23 --- GRAIN SIZE DISTRIBUTION (F) GRAVEL 0 0 SAND 33.5 59.4 SILT 41.3 22.7 CLAY 25.2 16.7 SO L DESCR I PT IONS: B1: Light brown clayey very fine sandy silt (ML) Al: Light brown silty very fine sand B7-0271-P1 87-12-724 3@ 7-10' SM Al 108.8 13.8 29.5 4.7 0 0 81.8 11.5 6.7 BUENA ENGINEERS, INC. December 9, 1987 BORING/DEPTH 5@ 5-10' 4@ 20-25' USCS SM ML SOIL DESIGNATION Al CK PT B2 MAXIMUM DENSITY (pcf) 1.10.2 110.1 OPTIMUM MOISTURE 13.9 13.2 ' ANGLE "OF I NT. FR I C. --- --- COHESION (psf) --- --- EXPANSION INDEX --- --- GRAIN SIZE DISTRIBUTION (7) GRAVEL 0 0 SAND 79.7 19.5 SILT 15.9 51.5 CLAY 4.4 29.0 SOIL DESCRIPTIONS: Al: Light brown silty very fine sand (SM) 132: Brown very fine sandy clayey silt (ML) C1: Grey brown very silty clay (CL) 1 @ 20' ML Cl 0 4.0 44.5 51.5 B7-0271-P1 87-12-724 BUENA ENGINEERS, INC. December 9, 1987 B-3 B7-0271-P1 87-12-724 RELATIVE BORING & DEPTH DRY DENSITY R MOISTURE COMPACTION 1 @ 1.0 87.7 1.1 79 3.0 90.6 1.5 82 % 5.0 88.8 3.2 80 % 10.0 89.2 3.1 82 % 15.0 90.8 0.8 83 % 20.0 96.8 15.3 89 % 2 @ 1.0 96.9 3.4 879 4.0 88.7 4.5 80 % 8.0 89.5 2.9 829 15.0 97.0 1.9 89 % 3 @ 1.0 99.4 21.1 89 % 3.0 98.2 17.0 88 % 5.0 95.3 22.9 86 % 10.0 98.7 6.6 90 % 15.0 96.0 5.0 88 % 20.0 88.3 32.5 80 % 25.0 99.7 13.6 91 % BUENA ENGINEERS, INC. B7-0271-P1 87-12-724 " IN -PLACE DENSITIES RELATIVE BORING & DEPTH DRY DENSITY X MOISTURE COMPACTION 4 @ 2.0 94.7 4.0 85 7 5.0 94.1 3.3 86 10.0 88.2 10.5 79 15.0 87.4 8.2 80 % 20.0 86.6 .15.5 799 25.0 J01.2 6.4 93 30.0 93.8 6.5 85 F 35.0 89.0 24.4 81 f 40.0 84.2 25.3 77 5 @ 2.0 91.3 3.0 84 6 @ 2.0 82.2 3.2 74 fo 5.0 92.5 2.0 85 7 10.0 93.6 2.0 85 15.0 79.8 5.0 72 7 @ 2.0 95.9 2.4 86 7 10.0 87.5 8.0 79 15.0 90.4 3.4 8370 8 @ 5.0 89.4 1:6 82 10.0 94.4 1.5 86 15.0 86.4 5.9 79 20.0 84.8 25.6 ---- 9 @ 3.0 98.5 4.2 90 BUENA ENGINEERS, INC. DATE 11-09-87 LOG OF BORING for LA OUINTA HOTEL EXPANSION BORING NO. 1 Job No. B';'-0271-P1 Report No. LOCATION Per Plan. .. L Q O ci 0 o L. O y 3 O d DESCRIPTIONE. *' �� C G U �o n. O 0 i°• F' 0 C o ? Q. L O 0O � aU° REMARKS AND ANALYSIS d31 44 21 32 23 19_ B.1: Light brown clayey very fine sandy silt. 87.7 90.6 88.8 1.1 1.5 3.2 ML 79 82 80 5 Al: Light brown silty very fine sand. 89.2 3.1 SM 82 10 B1: light brown clayey very fine sandy silt ML 15 Al: Light brown silty very fine sand. 90.8 96.8 0.8 15.3 SM 83 -- Interbedded clay layer (Cl) 20 y;.•; NOTE: The stratification lines represent approximate bound- aries between soil types and the actual transitions may be gradual. Relatively undisturbed ring sample. Total Depth = 211' No free water encountered B7-027141 MOISTUR* CONTONT IN Ptt&C6NT OF DZY WSIGWT Fo- O LL U m �- 111.0 O z 0o7 a z 109.0 Z } 107.0 g 13.0 15.0 17.0 M1kTMOD OP COMPACftON. ASTM D-1557-78, Method A or C SOIL. TVPir MAXIMUM DONSITY OPTIMUM MOISTURE B1 Hole 1 @ 1-5' 111.1 15.3 MAXIMUM DGNSITY—OPTIMUM MOISTUM CURVES BUENA ENGINEERS INC. Plate 67-M71-P1 MOISTUR* CONTSNT IN P1tRL6NT OF DQY W%1r-WT LL u m 3 a 110 z z 108 r a g 106 11 13 14 16 MSTNOD O!a COMPACTION. ASTM D -1557-78, Method A or C SOIL TYPir MAXIMUM DENSITY QPTIMUM MOI*TUBE:• Al Hole 1,@ 7-10' 108.8 13.8 MAXIMUM DGNSITY - OPTIMUM MOISTURE CURVE'S BUENA ENGINEERS INC. Pale x B7-0271-P1 MOISTURE C.ONT*NT IN PS&CrArNT OI: DRY WSIGWT F- 0 O LL u m 3 a 112.0 z z 110.0 r Z r g 108.0 11 13 15 M1kT1 C)D OP COMPACTION. ASTM D-1557-78, Method A or C SOIL. TYPGr MAXIMUM DSNSITY OPTIMUM MOISTURE Al check point Hole 5 @ 5-10' 110.2 13.9 MAXIMUM DGNSITY - OPTIMUM MOISTURE CURVZS BUENA ENGINEERS INC. Plate B7-0271-P1 MOISTURE CONTONT IN P1 &CItirNT OF DRY WSIGWT F- 6 LL u . m 3 a z z h x r g 117.0 115.0 11 13 15 M<TWOD OInCOMPACTION. ASTM D-1557-78, Method A or C soli. TYPir MAXIMUM DENSITY OPTIMUM MOISTURE B1 check point Hole 7 @ 0-2' 117.5 13.1 MAXIMUM DIirN61TY - OPTIMUM MOISTUM CURVES BUENA ENGINEERS INC. Plate B7-0271-P1 MOISTURE CONTSNT IN P1tRC&NT OF my WSIGWT 111 107 MST1400 OF COMPACTION. ASTM D-`1557-78, Method A or C SOIL. rYPir MAXIMUM OSNSITY OPTIMUM MOISTURE C1 Hole 4 @ 20-25' 110.1 13.2 MAXIMUM DraNSITY — OPTIMUM MOISTUR * CURVES BUENA ENGINEERS INC. Plate B7-0271-P1, 400-MAL LOAD IN KIP& PER COULQE FOOT 4.0 O 0.5 1.0 1.5 2.0 2.5 2.0 ' 3.5 • F- 0 IL3.0 R•5 0 SOIL Al: 1 @ 7-10' DIZLLCT %WRAIL DAYA FRICTION ANGLE 29.5 c COHESION 47 psf BUENA ENC..iNFERS INC B7-M71-P1 UOR.MAL. LOAD im Kips. PER iLouAgE FOOT 0 0.5 1.0 1.5 2.0 2.5 2.0 0 4. LL 9.0 Lb or III 2.5 of d- d Y 2.0 , Z a a �r of � I.3 d Y a Lo a 4•S 0 OI LLCT 4WEAQ OAYA FRICTION ANGLE 31° COHESION 141 psf BUENA ENGINEERS INC Mm ■uo uau o.0 ■ua ■■ua FOOTNOTES TO TABLE 29-A 1. Premoistening is required where specified in Table 29-A in order to achieve maximum and uniform expansion of soils prior to construction and thus limit structural distress caused by uneven expansion and shrinkage. Other systems which do not include premoistening may be approved by the Building Official when such alternatives are shown to provide equivalent safeguards against adverse effects of expansive soils. 2. Underfloor access crawl holes shall be provided with curbs extending not less than six (6) inches above adjacent grade to prevent surface water from entering the foundation area. 3. Reinforcement for continuous foundations shall be placed not less than 3" above the bottom of the footing and not less than 3 below the top of the stem. 4. Reinforcement shall be placed at mid -depth of slab. S. After premoistening, the specified moisture content of soils shall be maintained until concrete is placed. Required moisture content shall be verified by an approved testing laboratory not more than 24 hours prior to placement of concrete. -6. Crawl spaces under raised floors need not be premoistened except under interior footings. Interior footings which are not enclosed -by a continuous perimeter foundation system or equivalent concrete or masonry moisture barrier -complying with Section UBC 2907 (b) in this ordinance shall be designed and constructed as specified for perimeter footings in Table 29-A. 7. A grade beam not less than 12" x 12" in cross section, reinforced as specified 'for continuous foundations in Table 29-A, shall be provided at garage door openings. 8. Foundation stem walls which exceed a height of 3 times the stem thickness above lowest adjacent grade shall be reinforced'in accordance with Sections 2418 and 2614 in the UBC or as required by engineering design, whichever is more restrictive. 9. Bent reinforcing bars between exterior footing and slab shall be omitted when floor is designed as an independent, "floating" slab. 10. Fireplace footings shall be reinforced with a horizonal grid located 3" above the bottom of the footing and consisting of not less than No. 4 bars at 12" on center each way. Vertical chimney reinforcing bars shall be hooked under the .grid. TABLE NO. 29-A MINIMUM FOUNDATION REQUIREMENTS 10 Footings for Slab & Raised Floor Systems (2) (5) (10) Concrete Slabs M" Minimum Thickness v All Peri- Interior. foot- Reinforce - meter ings for slab meet for Premoistening Weighted Y v c Footings and raised continuous control for soils Piers under Expansion ° V 3 E-- (6) floors (6) footings Reinforce- Total under footings, raised floors Index i~ °�° c (3) (8) ment (4) thickness piers and slabs o E - o Depth below. natural of sand (5) (G) Z 1 [i tL surface of ground and finish gradq 0-20 1 6 12 6 12 12 None 6x6- Moistening of Piers allowed Very Low 2 8 15 7 18 18 Rcquircd 10/ 10 ground prior to for single (Non -Ex- 3 10 18 8 24 24 WWF 2" placing concrete floor loads pansive) recommended only 1 6 12 6 15 12 120% of optimum 21-50 2 3 8 10 15 18 7 8 18 24 1.8 24 144 top 6x6- moisture content to a depth of Piers allowed for single Low and bottom 10/10 4" 21" below lowest floor loads WWF adjacent grade. only Testing Required 1 G 12 6 21 12 144 top 6x6- 130% of optimum 2 8 12 8 21 18 and bottom 6/6 WWF moisture content 51-90 3 10 15 8 24 24 or #3 to a depth of 27" Piers not Medium c 24" 4" below lowest allowed adjacent grade. 113 bars (d 24" in ext, footing and bent 3' into slab (9) Testing Required 1 6 12 6 27 12 145 top 6x6- 140%. of optimum 2 8 12 8 27 18 and bottom 6/6 WWF moisture content 91-130 3 10 15 8 27 24 or #3 to a depth of 33" Piers not High c 24" e.w. 4" below lowest allowed adjacent grade. 113 bars (d 24" in ext, footing and bent 3' into slab (9) Testing Required Above 130 Very High Special Design by Licensed Engineer/Architect "Refer to next page for footnotcs. (1) thrmirh (in) APPENDIX C Standard grading specifications BUENA ENGINEERS, INC. C-1 STANDARD GRADING SPECIFICATIONS PROJECT: LA QUINTA HOTEL EXPANSION CLIENT: LANDMARK LAND COMPANY, INC. 1. These Standard Grading* Specifications have been prepared for the exclusive use of our client for specific application to referenced project in accordance with generally accepted soil and foundation engineering practices. No other warranty, expressed or implied, is made. 2. Buena Engineers, Inc., referred to as the soil engineer, should be retained to provide continuous soil engineering services during construction of the grading, excavation and foundation phases of the work. This is to observe compliance with the design concepts, specifications or recommendations and to allow design changes in the event that subsurface conditions differ from that anticipated prior to start of construction. 3. The presence of our field representative will be for the purpose of providing observation and field testing. Our work does not include supervision or direction. of the actual work of the contractor, his employees or agents. The contractor. for this project should be so advised. The contractor should also be informed that neither the presence of our field representative nor the observation and testing by our firm shall excuse him in any way from defects discovered in his work. It is understood that our firm will not be responsible for job or site safety on this project. Job and site safety will be the sole responsibility of the contractor. BUENA ENGINEERS, INC. C-2 4. If the contractor encounters subsurface conditions at the site that (a) are materially different from those indicated in the contract plans or in specifications, or (b) could not have been reasonably anticipated as inherent in the work of the character provided in the contract, the contractor shall immediately notify the owner verbally and in writing within 24 hours. This notification shall be a condition precedent before any negotiations for "changed or differing site conditions" can proceed. If the owner determines that conditions do materially so differ and cause an increase or decrease in the contractor's cost of, or the time required for, performance of any part of the work under this contract, then negotiations shall commence between owner and contractor to provide equitable adjustment to owner or contractor resulting therefrom. 5. Whenever the words "supervision", "inspection", or "control" appear they shall mean periodic observation of the work and the taking of soil tests as deemed necessary by the soil engineer for substantial compliance with plans; specifications and design concepts. 6. These specifications shall be integrated with the Soil Engineering Report of which they are a part. Should conflicting statements be found between these standard specifications and the itemized recommendations contained in the main body of the soil report, the latter shall govern. 7. These specifications shall consist of clearing and grubbing, preparation of land to be filled, filling of the land, spreading, compaction and control of the fill, and subsidiary work necessary to complete the grading of the filled areas to conform with the lines, grades and slopes as shown on the accepted plans. 8: The standard test used to define minimum densities of compaction work shall be the ASTM Test Procedure D 1557. Densities shall be expressed as a relative compaction in terms of the maximum density obtained in the laboratory by the foregoing standard procedure. BUENA ENGINEERS, INC. C-3 9. Field density tests will be performed by the soil engineer :during grading operations. At least one (1) test shall be made for each five hundred (500) cubic yards or fraction thereof placed with a minimum of two (2) tests per layer in isolated areas. Where sheepsfoot rollers are used, the soil may be disturbed to a depth of several inches. Density tests shall be taken in compacted material below the disturbed surface. When these tests indicate that the density of any layer of fill or portion thereof is below the required density, the particular layer or portion shall be reworked until the required density has been obtained. 10. Earth -moving and working operations shall be controlled to prevent water from running into excavated areas. Excess water shall be promptly removed and the site kept dry. Fill material shall not be placed, spread or rolled during unfavorable weather conditions. When the work is interrupted by heavy rain, fill operations shall not be resumed until field tests by the soil engineer indicate that the moisture content and density of the fill are as previously specified. IL Compaction shall be by sheepsfoot rollers, vibrating sheepsfoot rollers, multiple -wheel pneumatic -tired rollers or other types of acceptable compacting rollers. Rollers shall be of such design that they will be able to compact the fill to the specified density. Rolling shall be accomplished while the fill material is within the specified moisture content range. Rolling of each layer shall be continuous over its entire area and the roller shall make sufficient trips to insure that the required density has been obtained. 12. Existing structures, foundations, trash, debris, loose fill, trees (not included in landscaping), roots, tree remains and other rubbish shall be removed, piled or burned. or otherwise disposed of so as to leave the areas that have been disturbed with a neat and finished appearance free from debris. No burning shall be permitted in the area to be filled. 13. When fill material includes rock, large rocks will not be allowed to nest and voids must be carefully filled with small stones or earth and properly compacted. Rock larger than six (6) inches in diameter will not be permitted in the compacted fill without review as to location by the soil engineer. BUENA ENGINEERS, INC. C-4 Organic matter shall be removed from the surface upon which the fill, foundations or pavement sections are to be placed. The surface shall then be plowed or scarified to a depth of at least eight (8) inches and until the surface is free from ruts, hummocks or other uneven features which would tend to prevent uniform compaction by the equipment to be used. Specific recommendations pertaining to stripping and minimum depth of recompaction of native soils are presented in the main body of the soil report. Native soil free from organic material and other deleterious material may be used as compacted fill; however, during grading operations the soil engineer will re-examine the native soils for organic content. Imported material should be tested and reviewed by the soil engineer before being brought to the site. The materials used shall be free from organic matter and other deleterious material. Where fills are made on hillsides or exposed slope areas, greater than ten (10) percent, horizontal benches shall be cut into firm undisturbed natural ground to provide a horizontal base so that each layer is placed and compacted on a horizontal plane. The initial bench at the toe of the fill shall be at least ten (10) feet in width on firm, undisturbed natural ground at the elevation of the toe stake placed at the natural angle of repose or design slope. The width and frequency of succeeding benches will vary with the soil conditions and the steepness of slope. The selected fill material shall be placed in layers which, when compacted, shall not exceed six (6) inches in thickness. Layers shall be spread evenly and shall be thoroughly blade -mixed during spreading. After each layer has been placed, mixed and spread evenly, it shall be thoroughly compacted to a relative compaction of not less than ninety (90) percent. The fill operation shall be continued in six (6) inch compacted layers, as specified above, until the fill has been brought to the finished slopes and graded as shown on the accepted plans. BUENA ENGINEERS, INC. C-5 When the moisture content of the fill material is not sufficient. to achieve required compaction, water shall be added until the soils attain a moisture content so that thorough bonding is achieved during the compacting process. When the moisture content of the fill material is excessive, the fill material shall be aerated by blading or other satisfactory methods until the moisture content is reduced to an acceptable content to achieve proper compaction. Existing septic tanks and other underground storage tanks must be removed from the site prior to commencement of building, grading or fill operations. Underground tanks, including connecting drain fields and other lines, must be totally removed and the resulting depressions properly reconstructed and filled. Depressions left from tree :removal shall also be properly filled and compacted. The methods for removal of subsurface irrigation and utility lines will depend on the depth and location of the line. One of the following methods may be used: 1) Remove the pipe and compact the soil in the trench according to the applicable portions of these grading recommendations, 2) The pipe shall be crushed in the trench. The trench shall then be filled and compacted according to the applicable portions of these grading specifications, 3) Cap the ends of the line with concrete to mitigate entrance of water. The length of the cap shall not be less than five (5) feet. The concrete mix shall have a minimum shrinkage. Abandoned water wells on the site shall be capped according to the requirements of the appropriate regulatory agency. The strength of the cap shall be at least equal to the adjacent soils. The final elevation of the top of the well casing must be a minimum of thirty-six (36) inches .below adjacent grade prior to grading or fill operations. Structure foundations should not be placed over the capped well. BUENA ENGINEERS, INC.