GEOTECHNICAL INVESTIGATION VEHICLE WASH FACILITY OCEANO DUNES STATE VEHICLE RECREATION AREA

Transcription

1 GEOTECHNICAL INVESTIGATION VEHICLE WASH FACILITY OCEANO DUNES STATE VEHICLE RECREATION AREA PREPARED FOR CALIFORNIA NORTHERN SERVICE CENTER ONE CAPITOL MALL SUITE 500 SACRAMENTO, CALIFORNIA GEOCON PROJECT NO. S SEPTEMBER 2008

2 GEOCON CONSULTANTS, INC. G E O T E C H N I C A L E N V I R O N M E N T A L M A T E R I A L S Project No. S September, 2008 VIA ELECTRONIC AND U.S. MAIL Mr. Warren White California Northern Service Center One Capitol Mall, Suite 500 Sacramento, California Subject: VEHICLE WASH FACILITY OCEANO DUNES STATE VEHICLE RECREATION AREA OCEANO, CALIFORNIA GEOTECHNICAL INVESTIGATION Dear Mr. White: In accordance with your request and our work order dated July 7, 2008, we have prepared this geotechnical investigation report for the Vehicle Wash Facility project located at Oceano Dunes State Vehicle Recreation Area (SVRA) in Oceano, California. The accompanying report presents our findings, conclusions, and recommendations regarding the geotechnical aspects of developing the site as presently proposed. Based on the results of our investigation, the site has a high potential for seismic-induced soil liquefaction and/or lateral spreading. In our opinion, no other adverse geotechnical conditions are present that would preclude development at the site provided the recommendations of this report are incorporated into the design and construction of the project. Please contact us if you have any questions concerning the contents of this report or if we may be of further service. Sincerely, GEOCON CONSULTANTS, INC. DRAFT Jeremy J. Zorne, PE, GE Senior Project Engineer DRAFT R. Luke Montoya, PE Senior Project Engineer JJZ:RLM:RN:jaj (3) Addressee 3160 Gold Valley Drive, Suite 800 Rancho Cordova, California Telephone (916) Fax (916)

3 CONTENTS GEOTECHNICAL INVESTIGATION 1.0 PURPOSE AND SCOPE SITE AND PROJECT DESCRIPTION SOIL AND GEOLOGIC CONDITIONS Undocumented Fill Eolian/Alluvial Deposits Older Sand Dune Formation GROUNDWATER GEOLOGIC HAZARDS Regional Active Faults Ground Shaking Seismicity Liquefaction Lateral Spreading CONCLUSIONS AND RECOMMENDATIONS General Seismic Design Criteria Soil Excavation Characteristics Materials for Fill Groundwater and Wet Weather Grading Conditions Grading Shallow Foundation Design Criteria Concrete Sidewalks, Driveways, and Flatwork Asphalt Concrete (AC) Pavement Drainage FURTHER GEOTECHNICAL SERVICES Plan and Specification Review Testing and Observation Services LIMITATIONS AND UNIFORMITY OF CONDITIONS REFERENCES...13 FIGURES Figure 1, Vicinity Map Figure 2, Site Plan APPENDIX A FIELD EXPLORATION Figures A1 through A3, Logs of Exploratory Borings B1 through B3 APPENDIX B LABORATORY TESTING PROGRAM Figure B1, Summary of Laboratory Results Figure B2, Plasticity Index Result

4 GEOTECHNICAL INVESTIGATION 1.0 PURPOSE AND SCOPE This report presents the results of our geotechnical investigation for the construction of a new vehicle wash facility structure at the existing maintenance station for the Oceano Dunes State Vehicle Recreation Area (SVRA) located at the 300 block of Highway 1/Pacific Boulevard in Oceano, California. The approximate site location is depicted on the Vicinity Map, Figure 1. The purpose of our geotechnical investigation was to observe and sample the subsurface conditions encountered at the site and provide conclusions and recommendations relative to the geotechnical aspects of designing and constructing the proposed structure. To prepare this report, we performed the following scope of services: Performed a limited geologic literature review to aid in evaluating the geologic conditions present at the site. Performed a site reconnaissance to review project limits, evaluate drill rig access, and mark out exploratory boring locations for subsequent underground utility clearance. Paid requisite fees and obtained a drilling permit from the San Luis Obispo County Environmental Health Department (SLOEHD) Notified subscribing utility companies via Underground Service Alert (USA) a minimum of 48 hours (as required by law) prior to performing exploratory excavations at the site. Retained the services of a California C57-licensed drilling subcontractor to perform exploratory borings. Performed three exploratory borings (B1 through B3) with a truck-mounted drill rig equipped with hollow-stem augers. Borings were drilled to depths ranging from approximately 15 to 50 feet. Obtained representative soil samples from the exploratory borings. Logged the borings in accordance with the Unified Soil Classification System (USCS). Backfilled borings in accordance with SLOEHD permit requirements upon completion. Performed laboratory tests to determine pertinent geotechnical parameters. Prepared this report summarizing our findings, conclusions, and recommendations regarding the geotechnical aspects of developing the site as presently proposed. Details of our field exploration including boring logs are presented in Appendix A. Approximate locations of borings are shown on the Site Plan, Figure 2. Details of our laboratory testing program and test results are presented in Appendix B. Project No. S September, 2008

5 2.0 SITE AND PROJECT DESCRIPTION The maintenance station for Oceano Dunes SVRA is located on the west side of Highway 1 approximately ¾ mile south of Grand Avenue in Oceano. The maintenance station currently includes a vehicle maintenance area, staff services buildings, and residences for park staff. These facilities are connected by a long, asphalt-paved driveway with paved and unpaved parking stalls. Although a sitespecific topographic map was not available for our review as of the date of this report, based on observation, the relatively flat site gently slopes down toward the west. We understand California State Parks intends to construct a vehicle wash facility within the central parking lot area. The vehicle wash facility will likely include two drive-through vehicle wash bays with concrete masonry unit (CMU) walls and a metal roof. We anticipate that an additional equipment room would be integrated into the CMU structure to house the pressure wash and water recirculation equipment. Site configuration and locations of existing and proposed improvements are shown on the Site Plan, Figure SOIL AND GEOLOGIC CONDITIONS Soil and geologic conditions encountered at the site predominantly consist of surficial fill soil underlain by recent and older alluvial soils and sand dune deposits. Soil descriptions provided below include the USCS symbol where applicable. 3.1 Undocumented Fill We encountered undocumented fill in our three borings from the ground surface to a depths of about 1½ to 3 feet. Fill material generally consists of loose to medium dense, silty sand (SM), loose, poorly graded sand (SP), and loose, clayey sand (SC). Fill material is not considered suitable for direct support of the proposed structure. Removal and re-compaction recommendations are provided in this report. 3.2 Eolian/Alluvial Deposits We encountered eolian/alluvial deposits (recent sand dune deposits) below the fill in our borings to a depth of approximately 21 feet. These deposits generally consist of interbedded layers of loose to medium dense, clayey sand (SC) with variable gravel, stiff to hard, lean clay with sand (CL), medium dense to dense, clayey gravel (GC), and medium dense poorly graded sand (SP) with variable gravel. 3.3 Older Sand Dune Formation Below the recent sand dune deposits at a depth of approximately 21 feet, we encountered medium dense to dense older sand dune deposits. This material generally consists of interbedded silty sand (SM) and very stiff, lean clay (CL). Project No. S September, 2008

6 Subsurface conditions described in the previous paragraphs are generalized. Therefore, we advise the reader to consult the exploratory boring logs included in Appendix A. The logs include the soil type, color, moisture, consistency, and USCS of the materials encountered at specific locations and elevations. 4.0 GROUNDWATER We encountered groundwater in our borings during drilling at depths ranging from 11 to 17 feet. After completion of the borings, we measured groundwater at depths ranging from approximately 5.4 to 6 feet. It should be noted that fluctuations in the level of groundwater may occur due to variations in precipitation, temperature, seasonal fluctuations, and other factors. Mostly notably, the groundwater level could be influenced by ocean tides. Therefore, it is possible that future groundwater may be higher than the levels observed during our investigation. 5.0 GEOLOGIC HAZARDS 5.1 Regional Active Faults Based on our research, analyses, and observations, the site is not located on any known active earthquake fault trace. In addition, the site is not contained within an Alquist-Priolo Earthquake Fault Zone. Therefore, we consider the potential for ground rupture due to onsite active faulting to be low. In order to evaluate the distance of known active faults in proximity to the site, we reviewed local and regional geologic maps. The San Luis Range Fault is located approximately 1.3 miles to the northeast. The Los Osos Fault is located approximately 5½ miles to the northeast. The Hosgri Fault is located approximately 11½ miles to the southwest. 5.2 Ground Shaking We used the computer program Seismic Hazard Curves and Uniform Hazard Response Spectra, provided by the USGS to calculate the seismic design criteria at the site. The output summarizes sitespecific seismic design criteria based on the 2007 California Building Code (CBC), Chapter 16 Structural Design, Section 1613 Earthquake Loads. Using the USGS program, the estimated Peak Site Acceleration (PGA) at the site is 0.39g (S DS /2.5) using the Site Class D parameters. This acceleration corresponds to the Maximum Considered Earthquake (MCE) event with 2% chance of exceedence in a 50-year period (2,475-year return period). We used the USGS computer program 2002 Interactive Deaggregation to estimate the modal (most probable) magnitude (Mw) associated with the MCE based on probabilistic analysis. The Mw is a unitless parameter used to compare the amount of energy released during a seismic event. We calculated the estimated Mw of Project No. S September, 2008

7 While listing PGA is useful for comparison of potential effects of fault activity in a region, other considerations are important in seismic design, including frequency and duration of motion and soil conditions underlying the site. The site could be subjected to ground shaking in the event of an earthquake along the faults mentioned above or other area faults. 5.3 Seismicity Liquefaction Liquefaction is a phenomenon in which saturated cohesionless soils are subject to a temporary loss of shear strength due to pore pressure buildup under the cyclic shear stresses associated with intense earthquakes. Primary factors that trigger liquefaction are: moderate to strong ground shaking (seismic source), relatively clean, loose granular soils (primarily poorly graded sands and silty sands), and saturated soil conditions (shallow groundwater). Due to the increasing overburden pressure with depth, liquefaction of granular soils is generally limited to the upper 50 feet of a soil profile. According to mapping prepared by the County of San Luis Obispo (Liquefaction Hazards, County of San Luis Obispo, 2000), the project site is located in an area of moderate liquefaction potential. We encountered groundwater as shallow as 5.4 feet in our borings. We evaluated the potential for liquefaction at the site using our field investigation data, the methodology of Youd et. al. (2001), and in accordance with California Geological Survey (CGS) Special Publication 117 (1997). We used a MCE ground motion PGA of 0.39g (2,475-year seismic event), an earthquake modal magnitude (M w ) of 6.64, and a design groundwater depth of 4 feet. Our analysis identified potentially liquefiable sand layers at each of the exploratory boring locations. In general, liquefiable sandy layers are located between depths of about 4 to 44½ feet. If liquefaction were to occur, we estimate that it may result in total ground settlements on the order of 3 to 5 inches. Differential settlement would likely be about half of these amounts across a horizontal distance of approximately 30 feet. Our estimated total liquefaction-induced settlements are based on the volumetric strain of the liquefiable soils. However, there is not a continuous, non-liquefiable capping layer above the liquefiable layers, which generally helps resist ground loss through sand boils. Therefore, our settlement estimates should be considered lower-bound estimates, and the actual settlements due to liquefaction could likely be much greater if sand boils occur. Based on our discussions with you, we understand that the vehicle wash facility structure will not be inhabited, and for economic reasons, ground improvement to reduce liquefaction potential or deep foundation systems are not economically feasible for the project. We further understand that you recognize the possibility that if liquefaction were to occur, structural damage is likely. To reduce potential for structural damage, we recommend that the structure be supported on conventional strip and spread footings tied together with grade beams. Project No. S September, 2008

8 5.4 Lateral Spreading The USGS performed an extensive review regarding liquefaction and lateral spreading of the Oceano Dunes area in 2004 in response to the San Simeon earthquake of They performed numerous subsurface explorations between Highway 1/Pacific Boulevard and the ocean about ½ mile south of the site. They presented their conclusions in a report titled Liquefaction-Induced Lateral Spreading in Oceano, California During the 2003 San Simeon Earthquake. One of their conclusions is that lateral spreading (the slipping of a soil mass towards an open channel, such as the ocean, typically along liquefiable soil seams) is a high potential in the Oceano Dunes region. From our review of the USGS report, we believe that lateral spreading is likewise possible within the bounds of this project. 5.5 Soil Corrosion Screening We performed laboratory testing (minimum resistivity, ph, chloride and sulfate content) on one soil sample obtained from the project site (results presented in Appendix B). Based on resistivity test results, the soil sample is considered moderately corrosive. The test result for chloride ion content does not indicate a significant corrosive potential. Laboratory water-soluble sulfate content tests results indicate that the samples tested possess negligible sulfate exposure to concrete structures as defined by 2007 CBC Section and American Concrete Institute (ACI) 318; therefore, Type II cement may be used. Soil ph test results indicate the soil samples tested are generally neutral. Geocon does not practice corrosion engineering. Our conclusions are based on general screening criteria. Corrosion-sensitive buried metallic improvements (uncoated cast iron, steel, ductile iron, etc.) should be constructed in accordance with local requirements with regard to corrosion prevention measures. Typical measures for buried metallic improvements in Bay Area corrosive soils include the use of wrapping materials, cathodic protection, and/or increasing metal thicknesses to create a sacrificial section. Project No. S September, 2008

9 6.0 CONCLUSIONS AND RECOMMENDATIONS 6.1 General With the understanding that the structure could experience damaging differential settlements due to seismically-induced liquefaction and/or lateral spreading, no other soil or geologic conditions were encountered during our investigation that would preclude construction of the structure as planned, provided the recommendations contained in this report are incorporated into the design and construction of the project The conclusions and recommendations presented herein are based on our review of the referenced literature, analysis of data obtained from our field exploration program, laboratory testing program, and our understanding of the proposed project at this time. 6.2 Seismic Design Criteria There are no known surface expressions of active faults underlying the site. Potential seismic hazards at the site will likely be associated with possible ground shaking from an event along regional active faults. The structure should be designed in accordance with the seismic requirements contained in the 2007 CBC. Table 6.2 summarizes site-specific design criteria obtained from the 2007 CBC. TABLE CBC SEISMIC DESIGN PARAMETERS Parameter Value CBC Reference Site Class D Table Mapped Spectral Response Acceleration for Short Period, S S 1.46g Figure (3) Mapped Spectral Response Acceleration for 1-Second Period, S g Figure (4) Site Coefficient, F a 1.0 Table (1) Site Coefficient, F v 1.5 Table (2) Seismic Coefficient, S MS 1.46g Equation Seismic Coefficient, S M1 0.80g Equation Conformance to the criteria presented in Table 6.2 for seismic design does not constitute any kind of guarantee or assurance that significant structural damage or ground failure will not occur if a maximum level earthquake occurs. The primary goal of seismic design is to protect life and not to avoid structural damage, since such design may be economically prohibitive. 6.3 Soil Excavation Characteristics In our opinion, excavations at the site may be accomplished with light to moderate effort using typical heavy-duty grading/excavation equipment. We do not anticipate that Project No. S September, 2008

10 excavations will produce oversized materials (greater than 6 inches in maximum dimension) which would require special handling or placement Based on the predominantly granular, near-surface soils, we anticipate temporary excavations, such as utility trenches, may experience significant sloughing/caving. It is the contractor s responsibility to provide sufficient and safe excavation support as well as protecting nearby utilities, structures, and other improvements which may be damaged by earth movements. 6.4 Materials for Fill Excavated soils generated from cut operations at the site are suitable for use as engineered fill in structural areas provided they do not contain deleterious matter, organic material, or rock/cementations larger than 6 inches in maximum dimension Import fill material should be primarily granular with a very low or low expansion potential (Expansion Index less than 50), a Plasticity Index less than 15, be free of organic material and construction debris, and not contain rock larger than 6 inches in greatest dimension Environmental characteristics and corrosion potential of import soil materials should also be considered. Proposed import materials should be sampled, tested, and approved by Geocon prior to its transportation to the site. 6.5 Groundwater and Wet Weather Grading Conditions We do not anticipate groundwater to significantly affect grading operations. Significant groundwater infiltration within excavations less than 4 feet deep is not anticipated. Excavations deeper than 4 feet may encounter saturated soils and/or unstable subgrade conditions If grading commences in winter or spring, surface soils will likely be wet. Earthwork and pad preparation operations in these conditions may be difficult with low productivity. Often, a period of at least one month of warm and dry weather is necessary to allow the site to dry sufficiently so that heavy grading equipment can operate effectively. 6.6 Grading All earthwork operations should be observed and all fills tested for recommended compaction and moisture content by a representative of our firm. Project No. S September, 2008

11 6.6.2 References to relative compaction and optimum moisture content in this report are based on the American Society for Testing and Materials (ASTM) D Test Procedure. Structural building pad areas should be considered as areas extending a minimum of 5 feet horizontally beyond the outside dimension of the building, including footings and overhangs carrying structural loads Prior to commencing grading, a pre-construction conference with representatives of the client, grading contractor, and Geocon should be held at the site. Site preparation, soil handling and/or the grading plans should be discussed at the pre-construction conference Site preparation should begin with removal of existing surface/subsurface structures, underground utilities (if present), and debris. Excavations or depressions resulting from site clearing operations, or other existing excavations or depressions, should be restored with engineered fill in accordance with the recommendations of this report If present, surface vegetation consisting of grasses and other similar vegetation should be removed by stripping to a sufficient depth to remove organic-rich topsoil. The actual stripping depth should be evaluated prior to grading. Material generated during stripping is not suitable for use within 5 feet of structural foundations or within pavement areas but may be placed in landscaped areas, non-structural areas, or exported from the site As mentioned previously, our borings encountered undocumented fill to depths ranging from 1½ to 3 feet. We recommend that the entire structural building pad (as defined in Paragraph 6.6.2) be overexcavated at least 2 feet below existing grade. The bottom of the overexcavated area should be scarified 12 inches, uniformly moisture-conditioned near optimum moisture content, and compacted to at least 90% relative compaction. Scarification and re-compaction operations should be performed in the presence of a Geocon representative to evaluate performance of the subgrade under compaction equipment loading. The area should then be backfilled with engineered fill. We anticipate the majority of the excavated fill can be reused as engineered material, but it may require drying. If desired, the existing fill may be replaced with suitable, approved import material Engineered fill should be compacted in horizontal lifts not exceeding 8 inches (loose thickness) and brought to final subgrade elevations. Each lift should be moisture-conditioned near optimum and compacted to at least 90% relative compaction Underground utility trenches within structural areas should be backfilled with properly compacted material. Pipe bedding, shading, and backfill should conform to the requirements of the appropriate utility authority. Material excavated from trenches should be adequate for Project No. S September, 2008

12 use as general backfill above shading provided it does not contain deleterious matter, vegetation, or cementations larger than 6 inches in maximum dimension. Trench backfill should be placed in loose lifts not exceeding 8 inches. Lifts should be compacted to a minimum of 90% relative compaction near optimum moisture content. Compaction should be performed by mechanical means only; jetting of trench backfill is not recommended. 6.7 Shallow Foundation Design Criteria If future structural maintenance is tolerable and provided the foundation areas are graded in accordance with the recommendations of this report, the structure may be supported on conventional shallow foundations bearing entirely on engineered fill Foundations may consist of spread footings and strip footings connected by grade beams provided they extend at least 12 inches below lowest adjacent surface grade Underground utilities running parallel to footings should not be constructed in the zone of influence of footings. The zone of influence may be taken to be the area beneath the footing and within a 1:1 plane extending out and down from the bottom of the footing Shallow foundations proportioned as recommended above may be designed for an allowable bearing capacity of 2,000 pounds per square foot (psf) for dead plus live loads with a onethird increase for transient loads, including wind and seismic The allowable passive pressure used to resist lateral movement of the footings may be assumed to be equal to a fluid weighing 300 pounds per cubic foot (pcf). The allowable coefficient of friction to resist sliding is 0.30 for concrete against soil. Combined passive resistance and friction may be used for design provided that the frictional resistance is reduced by 50% The project structural engineer should determine reinforcement based on structural requirements Based on the allowable bearing capacity presented above and the anticipated building loads, we estimate that total foundation settlement under static loads will be less than one inch, with post-construction differential settlement of less than ½ inch between supports. These settlement estimates are in addition to the potential liquefaction-induced settlements discussed in Section 5.3. Project No. S September, 2008

13 6.8 Concrete Sidewalks, Driveways and Flatwork Sidewalk, curb, gutter within County right-of-way should be designed and constructed in accordance with the latest San Luis Obispo County Standard Specifications, as applicable Onsite exterior concrete flatwork, such as pedestrian sidewalks, may be supported directly on subgrade soils prepared in accordance with the recommendations of this report. Subgrade should be uniformly moisture-conditioned at or above optimum moisture content prior to placing concrete If desired, 4 inches of Class 2 aggregate base (AB) compacted to at least 90% relative compaction may be used as an aggregate cushion below sidewalks and flatwork, but is not specifically required from a geotechnical standpoint, assuming near-surface soils have a low expansion potential Exterior concrete flatwork should structurally independent of building foundations. To reduce the potential for concrete cracking, exterior concrete flatwork could be reinforced with No. 3 reinforcing bars spaced 18 inches center to center, each way. 6.9 Asphalt Concrete (AC) Pavement Based on our experience with similar soil types, laboratory tests, and engineering judgment, we recommend using a subgrade soil Resistance Value (R-Value) of 60 for design We recommend the following alternative AC pavement sections for design to establish subgrade elevations in pavement areas. The project civil engineer should determine the appropriate Traffic Index (TI) based on anticipated traffic conditions. Table 6.9 provides alternative pavement sections based on various design TIs. We can provide additional sections based on other TIs if necessary. TABLE 6.9 FLEXIBLE PAVEMENT SECTIONS Traffic Index AC AB Total Section Thickness Project No. S September, 2008

14 6.9.3 The recommended alternative pavement sections are based on the following assumptions: 1. Subgrade soil has an R-Value of Class 2 AB has a minimum R-Value of 78 and meets the requirements of Section 26 of the latest Caltrans Standard Specifications. 3. Class 2 AB is compacted to 95% or higher relative compaction at or near optimum moisture content. Prior to placing AC, the AB should be proof-rolled with a loaded water truck to verify stability. 4. Asphalt concrete should conform to Section 39 of the latest Caltrans Standard Specifications Drainage Adequate drainage is imperative to reduce the potential for erosion and subsurface seepage. Care should be taken to properly grade the finished surface around the building pad after the structure and other improvements are in place, so that drainage water is directed away from the building and toward appropriate drainage facilities. Final grade should slope a minimum of 2% away from the structure Experience has shown that even with these provisions, subsurface seepage may develop in areas where no such water conditions existed prior to site development. This is particularly true where a substantial increase in surface water infiltration has resulted from an increase in landscape irrigation. 7.0 FURTHER GEOTECHNICAL SERVICES 7.1 Plan and Specification Review We should review the improvement plans and specifications prior to final design submittal to assess whether our recommendations have been properly implemented and evaluate if additional analysis and/or recommendations are required. 7.2 Testing and Observation Services The recommendations provided in this report are based on the assumption that we will continue as Geotechnical Engineer of Record throughout the construction phase. It is important to maintain continuity of geotechnical interpretation and confirm that field conditions encountered are similar to those anticipated during design. If we are not retained for these services, we cannot assume any responsibility for other s interpretation of our recommendations or the future performance of the project. Project No. S September, 2008

15 8.0 LIMITATIONS AND UNIFORMITY OF CONDITIONS The recommendations of this report pertain only to the site investigated and are based upon the assumption that the soil conditions do not deviate from those disclosed in the investigation. If any variations or undesirable conditions are encountered during construction, or if the proposed construction will differ from that anticipated herein, Geocon should be notified so that supplemental recommendations can be given. The evaluation or identification of the potential presence of hazardous materials or environmental contamination was not part of the scope of services provided by Geocon. This report is issued with the understanding that it is the responsibility of the owner or their representative to ensure that the information and recommendations contained herein are brought to the attention of the design team for the project and incorporated into the plans and specifications, and the necessary steps are taken to see that the contractor and subcontractors carry out such recommendations in the field. The recommendations contained in this report are preliminary until verified during construction by representatives of our firm. Changes in the conditions of a property can occur with the passage of time, whether they are due to natural processes or the works of man on this or adjacent properties. Additionally, changes in applicable or appropriate standards may occur, whether they result from legislation or the broadening of knowledge. Accordingly, the findings of this report may be invalidated partially or wholly by changes outside our control. Therefore, this report is subject to review and should not be relied upon after a period of three years. Our professional services were performed, our findings obtained, and our recommendations prepared in accordance with generally accepted geotechnical engineering principles and practices used in this area at this time. No warranty is provided, express or implied. Project No. S September, 2008

16 9.0 REFERENCES 1. Blake, T.F., EQFAULT, Version. 3.00, California Division of Mines and Geology, Guidelines for Evaluating and Mitigating Seismic Hazards in California, Special Publication 117, adopted March 13, California Geological Survey, Wagner, D. L, Greene, H. G., Saucedo, G. J., Pridmore, C. L. (compilers), Geologic Map of the San Luis Obispo 30 x 60 Quadrangle and Adjacent Areas, California Geological Survey, Maps of Known Active Fault Near-Source Zones in California and Adjacent Portions of Nevada, February San Luis Obispo County, Dibblee, Hall, McClean, and Prior, Fault Map County of San Luis Obispo, San Luis Obispo County, Dibblee, Hall, McClean, and Prior, Geology County of San Luis Obispo, San Luis Obispo County, Dibblee, Hall, McClean, and Prior, Liquefaction Hazards, County of San Luis Obispo, Seed R.B. et al., Recent Advances in Soil Liquefaction Engineering: A Unified and Consistent Framework, April Unpublished reports, aerial photographs, and maps on file with Geocon. 10. United States Geological Survey, Holzer, T. L., Noce, T. E., Bennett, M. J., Di Alessandro, C., Boatwright, J., Tinsley, J. C., Sell, R. W., and Rosenberg, L. I., Liquefaction Induced Lateral Spreading in Oceano, California During the 2003 San Simeon Earthquake, Open File Report , United States Geological Survey, 2002 Interactive Deaggregations, Online United States Geological Survey, Seismic Hazard Curves and Uniform Response Spectra, Version 5.0.8, November Project No. S September, 2008

17 1 PISMO BEACH 101 James Blvd. James Pismo State Beach Five Cities Dr. El Wy. 101 Camino Oak Park Wy. Dr. Atlantic City Ave. Real P A C I F I C O C E A N Pismo State Beach Golf Course Pismo State Beach 1 PROJECT SITE 4th St. Pier Grand GROVER BEACH Ave. Mentone Farroll Highland Wy. 13th St. Ave. Ave. Oak Park Blvd. The Ave. Ash St. Pike ARROYO GRANDE Elm St. Brisco Grand Branch Rd. Fair Ave. Halcyon Rd. Rodeo St. Courtland St. Oaks Valley Branch Ave. Rd. 101 St. Oceano Airport 1 N 0 1/2 Scale in Miles G O L D VA L L E Y D R. S U I T E R A N C H O C O R D O VA, C A P H O N E F A X Oceano Dunes SRVA Vehicle Wash Facility S Oceano, California VICINITY MAP September 2008 Figure 1

18 N Wetland Border Meadow Creek B1 B3 Proposed Vehicle Wash Facility Location B2 Wetland Border Ranger Station Roosevelt HIGHWAY 1 / PACIFIC BOULEVARD Scale in Feet Drive G O L D VA L L E Y D R. S U I T E R A N C H O C O R D O VA, C A P H O N E F A X Base map prepared by California State Parks, dated 8/22/08 LEGEND: B1 Approximate Boring Location Oceano Dunes SRVA Vehicle Wash Facility S Oceano, California SITE PLAN September 2008 Figure 2

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