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05-3261 (CSCS) Geotechnical Investigation1 6F3 �-7 __o5 GEOTECHNICAL INVESTIGATION THE PAVILION AT LA QUINTA COMMERCIAL COMPLEX NEC HIGHWAY 111 AND ADAMS STREET LA QUINTA, CALIFORNIA -Prepared By- Sladden Engineering 39-725 Garand Lane, Suite G Palm Desert, California 92211 (760) 772-3893 717' iso 7�y9ow y �� t 1 6F3 �-7 __o5 GEOTECHNICAL INVESTIGATION THE PAVILION AT LA QUINTA COMMERCIAL COMPLEX NEC HIGHWAY 111 AND ADAMS STREET LA QUINTA, CALIFORNIA -Prepared By- Sladden Engineering 39-725 Garand Lane, Suite G Palm Desert, California 92211 (760) 772-3893 717' iso 7�y9ow y �� Sladden Engineering `L f Sladden Engineering `L :r Sladden .Engineering 6782 Stanton Ave., Suite A, Buena Park, CA 90621 (714) 523-0952 Fax (714) 523-1369 39-725 Garand Ln„ Suite G. Palm Desert, CA 92211 (760) 772-3893 Fax (760) 772-3895 February 17, 2004 Project No. 544-4010 04-02-I39 Thomas Enterprises, Inc. 300 Village Green Circle Smyrna, Georgia 30080 Attention: - Mr. Kevin Case Project: The Pavilion at La Quinta Commercial Complex NEC Highway 111 and Adams Street La Quinta, California Subject: Geotechnical Investigation Presented herewith is the report of our Geotechnical Investigation conducted at the site of the proposed Pavilion at La Quinta commercial complex to be located on the northeast corner of Highway 111 and Adams Street in the City of La Quinta, California. The investigation was performed in order to provide recommendations for site preparation and to assist in foundation design for the proposed commercial development. This report presents the results of our field investigation and laboratory testing along with conclusions .,. and recommendations for foundation design and site preparation. This report completes our original scope of services as described in our proposal dated December 15, 2003. We appreciate the opportunity to provide service to you on this project. If you have any questions regarding this report, please contact the undersigned Respectfully submitted, SLADDEN ENGIN ING Brett L. Anderso i Principal Engineer.." 'i SER/ma Copies: 6 / Thomas Enterprises, Inc. Vadden Engineering GEOTECHNICAL INVESTIGATION THE PAVILION AT LA QUINTA COMMERCIAL COMPLEX NEC HIGHWAY 11 I & ADAMS STREET LA QUINTA, CALIFORNIA February 17, 2004 TABLE OF CONTENTS NTRODUCTION....................................................................................................................... 1 SCOPEOF WORK................................................................................................:.................... 1 PROJECTDESCRIPTION......................................................................................................... 1 SUBSURFACECONDITIONS.................................................................................................. 2 CONCLUSIONS AND RECOMMENDATIONS...................................................................... 2 FoundationDesign................................................................................................................ 3 Settlements............................................................................................................................ 3 Lateral Design................................................................ 4 RetainingWalls.................................................................................................................... ExpansiveSoils 4 ..................................................................................................................... 4 ConcreteSlabs-on-Grade................:........................................................................:............ 4 SolubleSulfates ...:..I........................................................................................................ 4 TentativePavement Design.................................................................................................. 5 Shrinkageand Subsidence.................................................................................................... 5 GeneralSite Grading............................................................................................................ 5 1. Clearing and Grubbing................................................................................................ 5 2. Preparation of Building Areas..................................................................................... 6 3. Preparation of Surfaces to Receive Compacted Fill ...... ........ .... ...... ................... I....... 6 4. Placement of Compacted Fill..................................................................................... 6 5. Preparation of Slab and Pavement Areas................................................................... 6 6. Testing and Inspection............................................................................................... F 6 GENERAL..............................:.................:................................................................................. 7 APPENDIX A - Site Plan and Boring Logs Field Exploration APPENDIX B - Laboratory Testing Laboratory Test Results iWPENDIX C - 1997 UBC Seismic Design Criteria Sladden Engineering -A, February 17, 2004 -1- Project No. 544-4010 04-02-139 INTRODUCTION Phis report presents the results of our Geotechnical Investigation performed in order to provide recommendations for site preparation and the design and construction of the foundations for the proposed Pavilion at La Quinta commercial complex. The property is located on the northeast corner of Highway I I I and Adams Street in the City of La Quinta, California. The preliminary plans provided by Smith Consulting Architects indicate that the proposed commercial complex will include several major retail stores along with attached shop buildings and several detached retail pads. The associated site improvements will include paved driveways and parking lots, underground utilities, and landscape areas. SCOPE OF WORK Fhe purpose of our investigation was to determine certain engineering characteristics of the near surface soils on the site in order to develop recommendations for foundation design and site preparation. Our investigation included field exploration, laboratory testing, engineering analysis and the preparation of this report: Evaluation of environmental issues or hazardous materials was not within the scope of services provided. Our investigation was performed in accordance with contemporary geotechnical engineering principles and practice: We make no other warranty, either express or implied. PROJECT DESCRIPTION Fhe proposed project is located on the northeast corner of Highway 111 and Adams Street in the City of La Quinta, California. The preliminary site plan indicates that the project will include a retail complex occupying a total of 170,791 square feet and various associated site improvements. It is our assumption that the proposed commercial buildings will be of relatively lightweight reinforced masonry, steel -frame or wood -frame construction. The associated site improvements will include paved driveways and parking areas, landscape areas and various underground utilities. 'rhe project site is presently vacant and the ground surface is covered with sparse weeds. Prior to our field investigation the site was rough graded including cuts and fills that resulted in the creation of relatively level building pads. The previous rough grading is documented within our previous report dated May 3, 2000. Highway 1 l I and Adams Street are paved adjacent to the site and there are existing underground utilities along the streets. Commerce Way and Postal Road have also been constructed. Based upon our previous experience with similar lightweight commercial/industrial structures, we expect that isolated column loads will be less than 80 kips and wall loading will be less than 4.0 kips per linear loot. Future grading is expected to include minor cuts and fills to construct a level building pad and to accommodate site drainage. This does not include removal and recompaction of the foundation bearing soils within the building areas. If the anticipated foundation loading or site grading varies substantially from that assumed, the recommendations included in this report should be reevaluated. Sladden Engineering February 17, 2004 .2- Project No. 544-4010 04-02-139 SUBSURFACE CONDITIONS The site is underlain primarily by a generally thin profile of artificial fill soils overlying native fine - trained windblown sands with scattered sandy silt layers. Recovered ring samples and sampler penetration resistance (as measured by blowcounts) indicate that the site soils are somewhat inconsistent in density but density appears to generally increase with depth. Relatively undisturbed samples indicate dry density varying from 81 to 111 pcf. The site soils were found to be generally dry throughout the depth of our borings but some of the silty Byers were wet. Moisture content varying from I to 42 percent was determined for the samples obtained within our borings. laboratory classification testing indicates that the near surface soils consist primarily of fine grained silty sands. Expansion testing indicates that the surface soils are non -expansive and fall within the "very low" expansion category in accordance with the Uniform Building Code classification system. The somewhat inconsistent moisture conditions suggest that some of the near surface native soils underlying the site may be susceptible to settlements due to hydroconsolidation and compression. Groundwater was not encountered in our borings and groundwater is expected to be in excess of 100 feet below the existing ground surface. Groundwater should not be a factor in foundation design or construction. CONCLUSIONS AND.RECOMMENDATIONS Based upon our previous and recent field and laboratory investigations, it is our opinion that the proposed Pavilion at La Quinta commercial complex is feasible from a soil mechanic's standpoint provided that the recommendations included in this report are considered in building foundation design and site preparation. Due to the somewhat inconsistent conditions of the near surface soils, remedial grading including overexcavation and recompaction is recommended for the proposed building areas. We recommend that remedial grading within the proposed building areas include overexcavation and recompaction of the primary foundation bearing soils. Specific recommendations for site preparation are presented in the site grading section of this report. Groundwater was not encountered within our borings and groundwater is expected to be in excess of 100 feet below the existing ground surface. Due to the depth to groundwater, specific liquefaction analyses were not performed. Based upon the depth to_groundwater, the potential for liquefaction and -the related iurticial affects of liquefaction impacting the site are considered negligible.,r- --- - ,-The-site —is-. located within. an. -active seismic area of Southern California within approximatelyl8 7 kilometers of the San Andreas. fault. Strong ground motion resulting from earthquake activity along the nearby San Andreas or San Jacinto fault systems is likely to impact the site during the anticipated lifetime of the structures. Structures should be designed by professionals familiar with the geologic and seismic setting of the site. As a minimum, structure design should conform to Uniform Building Code (UBC) requirements for Seismic Zone 4. Pertinent seismic design criteria as outlined in the 1997 UBC, is surrunarized in Appendix C. Sladden .Engineering i rip February 17, 2004 -3- Project No. 5444010 04-02-139 Caving did occur within each of our exploratory borings and the surface soils will be susceptible to caving within deeper excavations. All excavations should be constructed in accordance with the normal CaIOSHA excavation criteria. On the basis of our observations of the materials encountered,_we, alticipate.that-the.subsoils.will,conform-to those described.by�CalOSHA as Type C. Soil conditions ffiouid be verified in -the field -by a "Competent person" employed by the Contractors J The surface soils encountered during our investigation were found to be non -expansive. Laboratory testing indicated an Expansion Index of 0, which corresponds with the "very low" category in accordance with UBC Standard 18-2. If imported soils are to be used during grading, they should have an Expansion Index of less than 20. The following recommendations present more detailed design criteria that have been developed on the basis of our field and laboratory investigation. Foundation Design The results of our investigation indicate that either conventional shallow continuous -footings or isolated pad footings that are supported upon properly compacted soils may be expected to provide satisfactory support for the proposed structures. Recompaction should be performed as described in the Site Grading Section of this report. lFootings_should_extend_at least 12 inches beneath lowest adjacent grade -for `single� ry structures... Isolated. square or_rec_tangula%footings atleast 2 -feet square may be designed using an allowable bearing value of 2000 pounds per square foot. Continuousrfootings'at"least-l2-inches Cwide may be designed using an allowable bearing value of 1800 pounds per square foot. Allowable increases of 200 psf for each additional 1 -foot of width and 200 psf for each additional [6 -inches of depth may be utilized for larger footings. The maximum allowable bearing pressure ,,'should be3000.psf..--The allowable bearing pressures aie for dead and frequently applied live !~loads and may be increased by, 1/3_to. resist .wind, seismic or other transient loading. - —� Because of the hydroconsolidation potential of some of the soils underlying the site, care should be taken to see that bearing soils are not allowed to become saturated from the ponding of rainwater or,irrigation. Drainage from the building areas should be rapid and complete. The recommendations made in the preceding paragraphs are based on the assumption that all footings will be supported upon properly compacted engineered fill soils. 6All grading shall -be ��rforme'd under the testing and inspecti6ii-of the -Soils Engineer or his representative—Prior to ;_t_he 7 placement -of concrete, we recommend that the footing excavations be inspected in order to verify that theyextend into compacted soil and are free of loose and disturbed materials Settlements: Settlements may result from the anticipated foundation loads. These estimated ultimate settlements are calculated to be a maximum of 1 -inch when using the recommended bearing values. As a practical matter, differential settlements between footings can be assumed as one-half of the total settlement. Sladden Engineering I. February 17, 2004 '4- Project No. 544-4010 04-02-139 Lateral Design: Resistance to lateral loads can be provided by a combination of friction acting at the base of -the slabs or foundations and passive earth pressure along the sides of the foundations. A•coefficient of friction of 0.45 between soil and concrete inay be used with dead _ - -- �lo.ad forces only. A passive earth _pressure of 275 pounds per square foot, per foot of depth, may be used for the sides of footings, which are poured against properly compacted native soils. Passive earth pressure should be ignored within the upper 1 -foot except where confined (such as beneath a floor slab). When used in combination, either the passive resistance or the coefficient of friction should be reduced by one-third. Retaining Walls:1 Retaining walls may be required_to accomplish the proposed construction. Cantilever -retaining walls may be (designed using "active" pressures. Active pressures may be estimated using -an equivalent fluid weight of 35 pcf for native backfill soils with levelJree- `draining backfill conditions. For walls.that•are restrained; "at rest" pressures should'be utilized in design, -At rest pressures_ may be estimated using an equivalent fluid weight of 55 pcf for native backfill soils with -level, free -draining backfill conditions... f _ Expansive Soils: Due to the prominence of non -expansive soils on the site, special expansive soil design criteria should not be necessary for the design of foundations and concrete slabs -on - grade. Final design criteria should be established by the Structural Engineer. Concrete Slabs -on -Grade: All surfaces to receive concrete slabs -on -grade should be underlain by recompacted soils as described in the Site Grading Section of this report. Where slabs are to receive moisture sensitive floor coverings or where dampness of the floor slab is not desired, we recommend the use of an appropriate vapor barrier. Vapor barriers should be protected by at least two inches of sand in order to reduce the possibility of damage and to aid in obtaining uniform concrete curing. Reinforcement of slabs -on -grade in order to resist expansive soil pressures may not be required, however reinforcement will have a beneficial effect in containing cracking due to concrete shrinkage. Temperature and shrinkage related cracking should be anticipated in all concrete slabs -on -grade. Slab reinforcement and the spacing of control joints should be determined by the Structural Engineer. Soluble Sulfates: The soluble sulfate concentrations of the surface soils were determined to be approximately 555 parts per million (ppm). Soluble sulfate concentration will likely change as a result of the recommended site grading. Soluble sulfate content should be determined after grading and appropriate concrete mix designs should be selected in accordance with UBC Table 19-A-3. Sladden Engineering R February 17, 2004 -5- Project No. 544-4010 04-02-139 Tentative Pavement Design: All paving should be underlain by a minimum compacted fill thickness of 12 inches (excluding aggregate base). This may be performed as described in the Site Grading Section of this report. R -Value testing performed during our previous investigation resulted in an R -Value of 62. On this basis, a pavement section of 3.0 inches of asphalt on 4.0 inches of base material should be applicable for the design of the majority of the onsite pavement. The appropriate pavement sections for off site improvements will be dependent upon traffic indices detennined by the City of La Quinta, California. Aggregate base should conform to the requirements for Class 2 Aggregate base in Section 26 of CalTrans Standard Specifications, January 1992. Asphaltic concrete should conform to Section 39 of the CalTrans Standard Specifications. The recommended sections should be provided with a uniformly compacted subgrade and precise control of thickness and elevations during placement. Pavement and slab designs are tentative and should be confirmed at the completion of site grading when the subgrade soils are in-place. This will include sampling and testing of the actual subgrade soils and an analysis based upon the specific traffic information Shrinkage and Subsidence: Volumetric shrinkage of the material that is excavated and replaced as controlled compacted fill should be anticipated. We estimate that this shrinkage could vary from 15 to 20 percent. Subsidence of the surfaces that are scarified and compacted should be between 0.1 and 0.2 tenths of a foot. This will vary depending upon the type of equipment used, the moisture content of the soil at the time of grading and the actual degree of compaction attained. These values for shrinkage and subsidence are exclusive of losses that will occur due to the stripping of the organic material from the site, the removal of deleterious materials and the removal of debris, and other subsurface obstructions. General Site Grading: All grading should be performed in accordance with the grading ordinance of the City of La Quinta, California. The following recommendations have been developed on the basis of our field investigation and laboratory testing: 1. Clearing and Grubbing: Proper clearing of any existing vegetation and debris will be very important. All surfaces to receive compacted fill should be cleared of roots, vegetation, debris, and other unsuitable materials which should be removed from the site. Soils that are disturbed due to the removal of the surface vegetation, previous improvements or artificial fill material should be replaced as controlled compacted fill under the direction of the Soils Engineer. Sladden Engineering M February 17, 2004 -6- Project No. 544-4010 04-02-139 2. Preparation of Building Areas: Within the building areas, removal and recompaction of the primary foundation bearing soils is recommended. As a minimum, removals within the building areas should extend to a depth of at least 3 feet below existing grade or 3 feet below the bottom of the footings, whichever is deeper. The exposed surface should be scarified, moisture conditioned and compacted so that a minimum of 90% relative compaction is attained. Once deleterious materials are removed, the native soils and artificial fill materials may be placed as controlled compacted fill. Overexcavation should be observed by a representative of Sladden Engineering and compaction should be verified by testing. Overexcavation should extend at least 5 feet laterally beyond the footings. 3. Preparation of Surfaces to Receive Compacted Fill: Other areas to receive compacted fill should be brought to near optimum moisture content and compacted to a minimum of 90% relative compaction. 4. Placement of Compacted Fill: Fill materials consisting of on-site soils or approved imported granular soils, should be spread in thin lifts, and compacted at near optimum moisture content to a minimum of 90% relative compaction. Imported material shall have an Expansion Index not exceeding 20. The contractor shall notify the Soils Engineer at least 48 hours in advance of importing soils in order to provide sufficient time for the evaluation of proposed import materials. The contractor shall be responsible for delivering material to the site that complies with the project specifications. Approval by the Soils Engineer will be based upon material delivered to the site and not the preliminary evaluation of import sources. Our observations of the material encountered during our investigation indicate that compaction will be most readily obtained by means of heavy rubber -wheeled equipment and/or vibratory compactors. At the time of our investigation, the subsoils were found to be quite dry. A more uniform moisture content should be attained during recompaction and fill placement. 5. Preparation of Slab and Pavement Areas: All surfaces to receive asphalt concrete pavement or concrete slabs -on -grade should be underlain by a minimum compacted fill thickness of 12 inches. This may be accomplished by a combination of scarification and recompaction of the surface soils and placement of the fill material as controlled compacted fill. Compaction of the slab and pavement areas should be to a minimum of 90 percent relative compaction. 46. Testing sand Inspection: During grading tests and observations should'be performed by the Soils Engineer or his representative in order to verify that the grading is being performed in accordance with the project specifications. Field density testing, shall be performed in accordance with acceptable ASTM test methods. The minimum acceptable t.degree of compaction should•be 90 percent of the maximum dry density as obtained by , the -ASTM- 1)1557-91 test method_. Where testing indicates ._insufficient -density,_ additional compaetive effort shall be applied until retesting indicates satisfactory compaction. Sladden Engineering ZV February 17, 2004 -7-Project No. 544-4010 04-02-139 GENERAL 1he findings and recommendations presented in this report are based upon an interpolation of the soil conditions between the exploratory boring locations and extrapolation of these conditions throughout the proposed building area. Should conditions encountered during grading appear different than those indicated in this report, this office should be notified. 1his report is considered to be applicable for use by Thomas Enterprises, Inc. and its consultants for the specific site and project described herein. The use of this report by other parties or for other projects is TIM authorized. The recommendations of this report are contingent upon monitoring of the grading operations by a representative of Sladden Engineering. All recommendations are considered to be tentative pending our review of the grading operations and additional testing, if indicated. If others are employed to perform any soil testing, this office should be notified prior to such testing in order to coordinate any required site visits by our representative and to assure indemnification of Sladden Engineering. Our investigation was conducted prior to the completion of plans for the project. We recommend that a pre job conference be held on the site prior to the initiation of site grading. The purpose of this meeting will be to assure a complete understanding of the recommendations presented in this report as they apply to the actual grading performed. Sladden Engineering 3ui,r3aur2trgr uappnlS 520.1 s;3uljOg utiid N!S v XIdNaddv APPENDIX A FIELD EXPLORATION For our field investigation, 10 exploratory borings were excavated on January 16, 2004, using a truck eounted hollow stem auger rig (Mobile B53) in the approximate locations indicated on the site plan included in this appendix. Continuous logs of the materials encountered were made on the site by a rzpresentative of Sladden Engineering. Boring logs are included in this appendix. Representative undisturbed samples were obtained within our borings by driving a thin-walled steel pnetration sampler (California split spoon sampler) or a Standard Penetration Test (SPT) sampler with a 140 pound hammer dropping approximately 30 inches (ASTM D1586). The number of blows required to drive the samplers 18 inches was recorded (generally in 6 inch increments). Blowcounts are indicated on the boring logs. The California samplers are 3.0 inches in diameter, carrying brass sample rings having inner diameters of 15 inches. The standard penetration samplers are 2.0 inches in diameter with an inner diameter of 1.5 inches. Undisturbed samples were removed from the sampler and placed in moisture sealed containers in order to preserve the natural soil moisture content. Bulk samples were obtained from the excavation spoils and samples were then transported to our laboratory for further observations and testing. Samples Mere then transported to our laboratory for further observations and testing. Sladden Engineering .i ._— — - 2 RfnME Ir 7.Dam i I!Lti.IJl! III: woanvn „ ;E fla3Ys L111 I 'J I ' I � : C 3 I.II I i9at9ffih.Abm�ond I�� 51 414 z ODAi il11Tf I 1 1 I. _ ..., •Ilii j.� - - — - .,� _ - _; nn rrT 10 10. PAMO rti pQ n • J I . E Boring Location Map The Pavilion at La Quinta North Approximate Boring Locations NWC Highway 1 l 1 and Adams Street La Quinta, California Sladden Engineering Project Number: 544-4010 jDate: 2-9-04 The Pavilion at La Quinta NWC Highway 111 and Adams Street / La Quinta, California Date: 1-16-04 Borine No. 1 Job No.: 544-4010 r3 a C y DESCRIPTION °; Q oREMARKS y 9E °J c r/a U OQ tip U a o o o U 0 Sand: Grey brown, SP/SM slightly silty, fine grained 5 4/13/17 89 2 14% passing H200 10 20/31/40 Silty Sand: Grey brown, SM 97 11 40% passing #200 very silty, fine grained 1s 30/30/47 Sand: Grey brown, SP Unrecovered Sample fine grained 20 _ - 21/50-6" 95 6 --- 3% passing #200 - R Recovered Sample Total Depth = 21.5' ® Disturbed Sample No Bedrock No Groundwater 25 30 35 40 45 50 Note: The stratification lines 5s represent the approximate boundaries between the soil types; the transitions may be gradual. The Pavilion at La Quinta NWC Highway I II and Adams Street / La Quinta, California Dater 1-1 6-04 Borin2 No. 4 Job No.: 544-4010 �.i 3 6 �o DESCRIPTION F A o z a REMARKS E o — " c4 zn U OG 'o a 0 o o c U 0 Sand: Grey brown, SP fine grained s 10/13/17 97 2 2% passing #200 10 19/32/40 Silty Sand: Grey brown, SM 101 4 --- 25% passing 9200 fine grained 15 13/24/25 Clayey Silt: Brown, sandy ML 87 17 --- 83% passing #200 20 Sand: Grey brown, SP 18/'0'x' fine grained 98 3 - 2% passing 9200 - Recovered Sample Total Depth = 21.5' No Bedrock No Groundwater 25 30 35 40 45 50 Note: The stratification lines 55 represent the approximate boundaries between the soil types: the transitions may be gradual. The Pavilion at La Quinta NWC Highway 111 and Adams Street / La Quinta, California Date: 1-16-04 orinL, No.6 Job No.:544-4010 CL,. o E99 Ci DESCRIPTION F a; i 3 o a CL c o160, �o E 0 0 c U REMARKS 0 _ 5 10 tis 10/16/20 17/28/40 19/35/35 Sand: Grey brown, fine grained " SP 101 97 3 2 --- 2% passing #200 3%passing #200 Clayey Silt:.Brown, sandy ML94 21 ---77% passing #200 - - - 20 25 30 35 40 45 50 - 55 - Recovered Sample "lbtal Depth = 16.5' No Bedrock No Groundwater Note: The stratification lines represent the approximate boundaries between the soil types; the transitions may be gradual. The Pavilion at La Quinta NWC Highway 111 and Adams Street / La Quinta, California Date: 1-16-04 Borine No. 9 Job No.: 544-4010 _ A `- o to U oQ DESCRIPTION rn 3 A a d c o U REMARKS 0 _ 5 10 ,s 20 _ 15/24/30 13/20/25 13/21/41 Sand: Grey brown, Fine grained " SP " " H] 98 --- 89 2 4 7 9 --- --- --- --- 2% passing #200 2% passing #200 5% passing 9200 o/o , 3 passing 1.200 :16/37/40 - 25 30 35 40 45 50 55 Recovered Sample ® Disturbed Sample Total Depth = 21.5' No Bedrock No Groundwater Note: -I"he stratification lines represent the approximate boundaries between the soil types; the transitions may be gradual. The Pavilion at La Quinta NWC Highway 111 and Adams Street / La Quinta, California Date: 1- 1 6-04 Borin No. 10 Job No.: 544-401-6 A o U ° M DESCRIPTION E~ 'o r/1 3rl- �` c u a 4o. a e c o o U REMARKS 0 - - s 31/50-6" Sand: Grey brown, fine grained SP 107 2 --- 2% passing #200 10 i5 14/1.6/18 17/30/30 Silty Clay: Brown with thin interbedded sand layers CL 81 42 --- 98% passing #200 Sand: Grey brown, tine grained SP 93 4 4% assing #200 20 25 30 35 40 45 50 55 - Recovered Sample Total Depth = 16.5' No Bedrock No Groundwater Note: The stratification lines represent the approximate boundaries between the soil types; the transitions may be gradual. APPENDIX B Laboratory Testing Laboratory Test Results Sladden Engineering APPENDIX B LABORATORY TESTING Representative bulk and relatively undisturbed soil samples were obtained in the field and returned to our laboratory for additional observations and testing. Laboratory testing was generally performed in two leases. The first phase consisted of testing in order to determine the compaction of the existing natural soil and the general engineering classifications of the soils underlying the site. This testing was lerfonned in order to estimate the engineering characteristics of the soil and to serve as a basis for xlecting samples for the second phase of testing. The second phase consisted of soil mechanics testing. This testing including consolidation, shear strength and expansion testing was performed in order to provide a means of developing specific design recommendations based on the mechanical properties of the soil. CLASSIFICATION AND COMPACTION TESTING unit Weight and Moisture Content Determinations: Each undisturbed sample was weighed and measured in order to determine its unit weight. A small portion of each sample was then subjected to testing in order to determine its moisture content. This was used in order to determine the dry density of the soil in its natural condition. The results of this testing are shown on the Boring Logs. 1llaximum Density -Optimum Moisture Determinations: Representative soil types were selected for maximum density determinations. This testing was performed in accordance with the ASTM Standard D1557-91, Test Method A. The results of this testing are presented graphically in this appendix. The maximum densities are compared to the field densities of the soil in order to determine the existing relative compaction to the soil. This is shown on the Boring Logs, and is useful in estimating the strength and compressibility of the soil. Classification Testing: Soil samples were selected for classification testing. This testing consists of mechanical grain size analyses and Atterberg Limits determinations. These provide information for developing. classifications for the soil in accordance with the Unified Classification System. This classification system categorizes the soil into groups having similar engineering characteristics. The results of this testing are very useful in detecting variations in the soils and in selecting samples for further testing. SOIL MECHANIC'S TESTING Direct Shear Testing: Two bulk samples were selected for Direct Shear Testing. This testing measures the shear strength of the soil under various normal pressures and is used in developing parameters for foundation design and lateral design. Testing was performed using recompacted test specimens, which were saturated prior to testing. Testing was performed using a strain controlled test apparatus with normal pressures ranging from 800 to 2300 pounds per square foot. Expansion Testing: These bulk samples were selected for Expansion testing. Expansion testing was performed in accordance with the UBC Standard 18-2. This testing consists of remolding 4 -inch diameter by l -inch thick test specimens to a moisture content and dry density corresponding to approximately 50 percent saturation. The samples are subjected to a surcharge of 144 pounds per square foot and allowed to reach equilibrium. At that point the specimens are inundated with distilled water. The linear expansion is then measured until complete. Sludden Engineering :nraaut�rr� tidppv1S u3TSaQ DIWSiaS 09A L66T � A'IQI�I�dd� 1997 UNIFORM BUILDING CODE SEISMIC DESIGN INFORMATION The International Conference of Building Officials 1997 Uniform Building Code contains substantial revisions and additions to the earthquake engineering section in Chapter 16. New concepts contained in (de updated code that will likely be relevant to construction of the proposed structures are summarized lelow. Ground shaking is expected to be the primary hazard most likely to affect the site, based upon proximity to significant faults capable of generating large earthquakes. Major fault zones considered to be most likely to create strong ground shaking at the site are listed below. Fault Zone Approximate Distance From Site Fault Type (1997 UBC San Andreas 8.7 km A San Jacinto 32 km A Based on our held observations and understanding of local geologic conditions, the soil profile type judged applicable to this site is SD, generally described as stiff or dense soil. The site is located within UBC Seismic Zone 4. The following table presents additional coefficients and factors relevant to seismic mitigation for new construction upon adoption of the 1997 code. Sladden Engineering Near -Source Near -Source Seismic Seismic Seismic Acceleration ``Velocity Coefficient Coefficient Source Factor Na, Factor Nv Ca Cv ,San Andreas _ ___ - 1.1 1:3 1 0.44 Na 0.64 N, San Jacinto 1.0 .1.0 170.44 Na 0.64 N,, Sladden Engineering i v E Q F :+ U L `C Version 3.00 DETERMINISTIC ESTIMATION OF PEAK ACCELERATION FROM DIGITIZED FAULTS JOB NUMBER: 599-4010 DATE: 02-0E-2005 JOB NAME: NWC Highway 111 & Adams Street Lc� Quinta, California CALCULATION NAME: Test Run Analysis FAULT -DATA -FILE NAME: CDMGFLTE.DAT SITE COORDINATES: SITE LATITUDE: 33.7094 SITE LONGITUDE: 116.2844 SEARCH RADIUS: 100 m'_ ATTENUATION RELATION: 5) Boore et. al. (1997) Horiz_. - SOIL (310) UNCERTAINTY (M=Median, S=Sigma): M Number of Sigmas: 0.0 DISTANCE MEASURE: cd_2drp SCOND: 0 Basement Depth: 5.00 km Campbell SSR: Campbell SHR: COMPUTE PEAK HORIZONTAL ACCELERATION FAULT -DATA FILE USED: CDMGFLTE.DAT MINIMUM DEPTH VALUE (km): 0.0 --------------- EQFAU' T SUMMARY --------------- ----------------------------- DETERMINISTIC SITE PARAMETERS ----------------------------- Page 1. ------------------------------------------------------------------------------- I IESTIMATED MAX. EARTHQUAKE EVENT 1 APPROXIMATE I ------------------------------- ABBREVIATED I DISTANCE I MAXIMUM I PEAK JEST. SITE FAULT NAME 1 mi (km) IEARTHQUAKEI SITE JINTENSITY i I MAG.(Mw) I ACCEL. g JMOD.MERC. SAN ANDREAS - Coachella I 5.4( 8.7)1 7.1 J 0.371 1 IX SAN ANDREAS - Southern 1 5.4( 8.7)1 7.4 J 0.434 1 X BURNT MTN. 1 17.1( 27.6)1 6.4 1 0.11.8 I VII EUREKA PEAK 1 18.1( 29.1)1 6.4 1 0.113 1 VII SAN ANDREAS - San Bernardino 1 18.5( 29.8)1 7.3 1 0.178 1 VIII SAN JACINTO-ANZA J 21.3( 34.3)1 7.2 1 0.152 1 VIII SAN JACINTO-COYOTE. CREEK 1 21.7( 34.9)1 6.8 J 0.122 J VII PINTO MOUNTAIN 1 29.9( 48.1)! 7.0 1 0.106 J VII EMERSON So. - COPPER MTN. 1 31.5( 50.7)1 6.9 J 0.096 1 VII LANDERS J 32.2( 51.9)1 7.3 J 0.117 1 VII PISGAH-BULLION MTN.-MESQUITE LK J 33.7( 54.2)1 7.1 J 0.102 J VII SAN JACINTO,- BORREGO J 35.6( 57.3)1 6.6 J 0.075 J VII SAN JACINTO-SAN JACINTO VALLEY J 36.4( 58.6)1 6.9 1 0.086 J VII NORTH FRONTAL FAULT ZONE (East) 1 37.2.( 59.8)1 6.7 1 0.093 J VII EARTHQUAKE VALLEY 1 40.3( 64.8)1 6.5 0.065 J VI BRAWLEY SEISMIC ZONE 1 41.6( 66.9)1 6.4 1 0.060 1 VI JOHNSON VALLEY (Northern) 1 43.1( 69.3)1 6.7 1 0.068 J VI ELSINORE-JULIAN 1 43.6( 70.2)1 7.1 J 0.083 J VII CALICO - HIDALGO 1 44.8( 72.1)1 7.1 1 0.082 1 VII ELSINORE-TEMECULA 1 47.8( 76.9)1 6.8 1 0.066 1 VI LENWOOD-LOCKHART-OLD WOMAN SPRGSJ 48.8( 78.6)1 7.3 1 0.085 1 VIl ELMORE RANCP 1 49.0( 78.8)1 6.6 J 0.059 1 VI NORTH FRONTAL FAULT 'ZONE (West; 1 49.2( 79.2)1 7.0 J 0.088 1 VII ELSINORE-COYOTE MOUNTAIN 1 51.6( 83.1)1 6.6 J 0.062 1 VI SUPERSTITION MTN. (San Jacinto) 1 53.7( 86.4)1 6.6 1 0.055 1 VI SUPERSTITION HILLS (San Jacinto)I 54.6( 87.8)1 6.6 1 0.054 1 VI HELENDAL£ - S. LOCKHARDT 1 56.7( 91.3)1 7.1 1 0.068 1 VI SAN JACINTO-SAN BERNARDINO 1 58.7( 94.5)1 6.7 1 0.054 1 VI ELSINORE-.GLEN IVY 1 61.3( 98.7)1 6.8 J 0.055 1 VI CLEGHORN 1 66.1( 106.3)1 6.5 J 0.044 1 VI IMPERIAL 1 68.7( 110.6)1 7.0 1 0.056 1 VI L•AGUNA SALADA J 71.8( 115.6)1 7.0 1 0.054 J VI CUCAMONGA 1 73.8( ].1.8.7)1 7.0 1 0.064 J VI CHINO -CENTRAL AVE. (Elsinore) 1 74.3( 119.5)1 6.7 1 0.054 1 VI NEWPORT-INGLEWOOD (Offshore) 1 76.1( 122.5)1 6.9 1 0.049 J VI ROSE CANYON 1 76.2( 122.6)1 6.9 J 0.049 1 VI WHITTIER 1 78.4( 126.1)1 6.8 1 0.045 J VI SAN ANDREAS - Mojave 1 82.8( 133.2)1 7.1 J 0.051 1 VI SAN ANDREAS - 1857 Rupture 1 82.8( 133.2)1 7.8 1 0.073 1 VII SAN JOSE 1 85.5( 137.6)1 6.5 1 0.044 1 VI ---------------- DETERMINTSTIC SITE PARAMETY:R ----------------------------- Pace 2 I ESTIMATED IhAX. EAiJHQUAKE E:.VE„T I yPPROXIVATE i ------------------------------- ABBRE-VIATED I D1., '"A.NCE MAXIM! K I PEAK JEST. SITE ArILr NAME I rr.i (:err) i EARTHQUAKE I SITE I INTENS='P-: I ___________====1=====____=====1=====_ MAG. (Mo -r) I ACCEL. g IM01).NERC. GRAVEL HILLS - HARPER LAKE 1 88.2( 142.0); --:-=1======-===1=====____ 6.9 1 0.043 1 Vi SIERRA MADRE 1 88.4( 142.3)1 7.0 1 0.056 1 VI ELYSIAN PARK THRUST J 90.6( 195.8): 6.'1 1 0.047 i VT CORONADO BANK 1 91.3( 157.0)1 7.4 1 0.055 ; V: P�E`nrPORT-IPiGLE410C!J (L.A.Sasir.) 1 94.6( 152.2;• ! 6.9 I 0.041 V CLAMSIIELT.-SAW PT T 1 96.9( 156.0) 1 6.5 1 C.040 I V COMPTON THRUS"' 1 97.3( ;56.6)1 6.8 1 C.046 Vl PALOS VERDES 99.5 ( 160.21,1 7.?. 1 0.044 V= a ***-A' #'*.F**+ri*#*Yi+* ai v'L *r a *a-�**# # i * i *** k #P # * /, f +1:- # ► i A- -END OF SEARCH- 48 FAULTS FOUND WITFIN THE SPECIFIED SEARCH RADIUS. THE SAN ANDREAS - Coachella FAULT IS CLOSEST TO THE. SITE. IT IS ABOUT 5.4 MILES (8.7 km) AWAY. LARGEST MAXIMUM -EARTHQUAKE SITE ACCELERATION: 0.4345 g 1100 1000 900 800 700 600 500 400 CALIFORNIA FAULT MAP NWC Highway I I 1 $ Adams Street / L,a Quinta -100 -400 -300 -200 -100 0 100 200 300 400 500 600 STRIKE --SLIP FAULTS 5) Boore et al. (1997) Horiz. - SOIL (31.0) M=5 M=6 M=7 M=8 1 .001 1 10 100 Distance f adistj (km) DIP -SLIP FAULTS 5) Boore eta]. (1997) Horiz. -SOIL (310) M=5 M=6 M=7 M=8 1 n o .1 c� L a U U Q .01 10 100 Distance [adistj (km) BLIND -THRUST FAULTS 5) Boore et al. (1997) Horiz. - SOIL (3 10) M=5 M=6 M=7 M=8 1 v� 0 c� a� a� U U � .01 .001 1 10. 100 Distance (adist] (km) MAXIMUM EARTHQUAKES NWC Highway 11. 1 & Adams Street / La Quinta 1 ,t �L MAXIMUM EARTHQUAKES NWC Highway 11. 1 & Adams Street / La Quinta 1 01 .001 .1 1 10 100 Distance (mi) o M a� (D U U Q 01 .001 .1 1 10 100 Distance (mi) EARTHQUAKE MAGNITUDES & DISTANCES NWC Highway l 1 l & Adams Street / La Quinta 7.75 7.50 7.25 a) a_. 'c 7.00 c� 6.75 6.50 .1 1 10 100 Distance (mi)