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HomeMy WebLinkAboutCT 06-16; Carlsbad Boat Club; Geotechnical Report; 2007-03-06GEOTECHNICAL REPORT PROPOSED CONDOMINIUM COMPLEX 4509 ADAMS STREET CARLSBAD, CALIFORNIA MARCH 2007 PREPARED FOR: VIP PARTNERS 1861 SOUTHVIEW DRIVE CARLSBAD, CALIFORNIA PREPARED BY: GeoLogic Associates 16885 West Bernardo Drive, Suite 305 San Diego, California 92127 (858)451-1136 HL(Jh!VED NAR 2 0 20.^7 UTY OF CAFILSBAD PLANNING DEPT GeoLogic Associates Geologists, Hydrogeologists and Engineers March 6, 2007 Project No. 2007-0014 Mr. Jim Courtney VIP Partners 1861 Southview Drive Carlsbad, California 92008 GEOTECHNICAL REPORT PROPOSED CONDOMINIUM COMPLEX 4509 ADAMS STREET CARLSBAD, CALIFORNIA In accordance with your request and authorization, GeoLogic Associates (GLA), has conducted a geotechnical investigation for the proposed condominium complex at 4509 Adams Street m Carlsbad, California (Figure 1, Vicinity Map). Based on the results of GLA's study, it is our opinion that the proposed site improvement is feasible fi-om a geotechnical perspective provided the recommendations presented, herein, are incorporated into the design and construction of the project. The accompanying report provides geotechnical conclusions and recommendations relative to the proposed development. We appreciate this opportunity to be of service. If you have any questions regarding this report, please do not hesitate to contact the undersigned. GeoLogic Associates Ted M. Primas Project Geologist Supervising Geotechnical Engineer Distribution: (4) Addressee Attachments: Figure 1 - Vicinity Map Figure 2 - Boring Location Map Figure 3 - Cross Section A-A' Figure 4 - Shoring Design Appendix A - Boring Logs Appendix B - Laboratory Testing Procedures and Test Results Appendix C - Seismic Analysis 16885 W. Bernardo Dr., Suite 305, San Diego, CA 92127 Phone: (858) 451-1136 Fax: (858) 451-1087 1.0 INTRODUCTION 1.1 Purpose and Scope This report presents the results of our geotechnical investigation for the proposed condominium complex at 4509 Adams Street in Carlsbad, California (Figure 1). The proposed development will include constiuction of a four level (three living levels and one parking level) condominium complex. The site is currently occupied by two existing structures. The residential structure is proposed to be razed and the boathouse will remain. Investigation of the boathouse was not within the scope of this report. This investigation was performed in accordance with the GLA's proposal. Our scope of services specifically included: • Review of available pertinent, published and unpublished geotechnical literature and maps. • Field reconnaissance of the existing onsite geologic/geotechnical conditions. • Subsurface exploration by a GLA geologist consisting of excavation, logging and sampling of four exploratory borings across the site to a maximum depth of 36.5 feet below existing grade. • Laboratory testing of representative soil samples obtained fi-om the subsurface exploration. • Analysis of the geotechnical data obtained fi-om the field sampling and laboratory testing. • Preparation of this report presenting our findings, conclusions, and geotechnical recommendations with respect to the proposed site improvements. -2- C:\Active\_Projects\2007\2007-0020 - Courtney Adams Condos\Final ReportWIP Partners Adams Reportdoc GeoLogic Associates 2.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING 2.1 Document Review Available geologic and geotechnical literature pertaining to the project site and surrounding areas was reviewed. These docxmients included published topographic maps, geologic maps, and reports. Specific documents reviewed are referenced in Section 8.0. 2.2 Site Reconnaissance GLA personnel visited the site to observe and map geologic conditions. Swface conditions were noted, including the general geologic and topographic setting, surface soils and related conditions. The exploratory boring locations were selected as well. 2.3 Subsurface Exploration Subsurface exploration consisted of excavating four exploratory borings with a Mobil B-53 drill rig. All borings were backfilled prior to the GLA representative leaving tiie site. The excavation of the borings was performed under the supervision of a GLA geologist who also logged the borings and obtained samples for subsequent examination and laboratory testing. Disturbed samples were obtained from the borings for visual observation and testing in the laboratory. Relatively undisturbed samples were also obtained fi-om Modified CaUfomia Samplers. Subsurface materials were visually classified in the field in accordance with standard engineering and geologic practices. Soil samples were classified using the Unified Soil Classification System explained in Appendix A. Details of the subsurface exploration and exploratory boring logs are presented in Appendix A. 2.4 Laboratory Testing Laboratory tests were performed to provide geotechnical parameters for engineering analyses. The testing program was designed to fit the specific needs of this project. Tests of selected samples retiieved fi-om tiie borings included direct shear, expansion index testing, R-Value, and corrosivity assessments (including soluble sulfate, pH, and minimum resistivity). The results of the tests are summarized in Appendix B. -3- C:\Active\_Projects\2007\2007-0020 - Comtaey Adams Condos\Final ReportWIP Partners Adams Reportdoc GeoLogic Associates 3.0 SITE CONDITIONS 3.1 Site Location/Conditions and Proposed Development The project site is located on 4509 Adams Street in Carlsbad, California (Figure 1). The site is bounded to the north by Adams Street, to the south by the Agua Hedionda Lagoon, and the east and west by residential construction. The site slopes steeply to the south. A single-family residence occupies the central portion of the site and a smaller boathouse lies to the south just north of the lagoon. Elevations range fi-om 50 feet near the northern portion of the site (near Adams Stieet) to approximately 10 feet mean sea level near the boathouse. The single-family residence will be removed for the new development and the boat house will remain. The lowest finish floor of the parking level is anticipated to be 8 feet mean sea level necessitating an excavation on the order of 40+ feet fi-om the street level to the lowest finish floor. A tie-back wall is anticipated to support this excavation. A concrete driveway will coimect Adams Stieet to the parking level. The proposed construction layout for the site is shown on Figure 2. 3.2 Subsurface Conditions and Groundwater The subject site is located in a coastal area of the Peninsular Ranges Geomorphic Province of California. This area extends fi-om the coastal plain northeastward to the Elsinore fault zone. The Carlsbad area is characterized by low rolling hills separated by the intermediate to broad valleys inland and lagoons near the coasL In general, this area is imderlain by the Tertiary-aged Santiago Formation, capped by Quaternary-aged Terrace Deposits, colluvium, and fill soils. A description of these units as encountered on the site follows. Fill soils were encountered in all four borings. The fill soils ranged fi-om one to four feet thick and were described as stiff clayey silt, fine clayey sand, and silty sand. These materials are not considered suitable for support of new fill soils or the proposed improvements. Colluvial soils were encountered in all borings except for B-2. Colluvium is derived fi-om weathering of imderlying material and downslope movement of these materials. The colluvium was described as stiff clayey silt to loose clayey sand and was encountered below the fill soils ranging fiom 2 to 6 feet thick. The colluvium in the area of Boring B-2 is anticipated to be removed during excavation. The colluvium in the area of Borings B-3 and B-4 is anticipated to be removed and recompacted during earthwork construction. In their current condition, these materials are not considered suitable for support of new fill soils or proposed improvements. -4- C:\Active\_Projects\2007\2007-0020 - Courtney Adams Condos\Final ReportWIP Partners Adams Report doc GeoLogic Associates Terrace Deposits were encountered below the fiU/coUuvium soils in the area of Borings B-1 and B-2. These materials are described as medium dense, reddish brown, fine silty sandstone. These materials are also anticipated to be removed during earthwork construction. The Santiago Formation is the bearing unit or "bedrock" material on the site. This formation is described as yellowish gray fine silty sandstone and has adequate bearing capacity. This formation is anticipated to be exposed at the lowest finish floor elevation except for the extieme southern portion of the parking level footprint where some fill/colluvial soils may be encountered. Groundwater was not encountered in the borings on the site. Minor seepage was encountered at a depth of 7.5 feet (elevation of 3.5 feet mean sea level) in Boring B-3. The groundwater level will fluctuate seasonally, and considering the time of year and the last few years of below average precipitation, the groundwater table at the time of consfaiiction will likely be higher. Groundwater/seepage will likely be encotintered during excavation/recompaction at the southern portion of the site and special construction dewatering techniques may have to be employed to contioi groundwater during the anticipated removals especially at the southern portion of the parking level. 4.0 FAULTING AND SEISMICITY 4.1 Faulting Our discussion of faults on the site is prefaced with a discussion of California legislation and policies concerning the classification and land-use criteria associated with faults. By definition of the California Geological Survey, an active fault is a fault that has had surface displacement within Holocene time (about the last 11,000 years). The state geologist has defined a potentiallv active fault as any fault considered to have been active during Quaternary time (last 1,600,000 years). This definition is used in delineating Earthquake Fault Zones as mandated by the Alquist- Priolo Geologic Hazards Zones Act of 1972 and as subsequently revised in 1975,1985, 1990, 1992, and 1994. The intent of this act is to assure that unwise urban development and certain habitable structures do not occur across the tiaces of active faults. The subject site is not included within any Earthquake Fault Zones as created by the Alquist-Priolo Act. Our review of available geologic literature (Section 8.0) indicates that there are no known major or active faults on or in the immediate vicinity of the site. The nearest active regional fauhs are the Rose Canyon Fault Zone, the Newport-Inglewood Fault (offshore), the Coronado Bank Fault, -5- C:\Active\_Projects\2007\2007-0020 - Courtney Adams Condos\Final ReportWIP Partners Adams Reportdoc GeoLogic Associates and the Elsinore Fault Zone located approximately 5.0, 6.0, 21.1, and 24.1 miles fi-om tiie site, respectively. 4.2 Seismicity The site can be considered to lie within a seismicaliy active region, as can all of Southern California. From a deterministic standpoint. Table 1 identifies potential seismic events that could be produced by the maximum earthquake event. Table 1 Seismic Parameters for Active Faults (Blake, 2004a and 2004b) Fault Zone (Seismic Source) Distance to Site (mUes) SUp Rate (nun/yr) * Maximum Earthquake Event Design Eartliquake (UBC, 1997/CBC, 2001) Fault Zone (Seismic Source) Distance to Site (mUes) SUp Rate (nun/yr) * Moment Magnitude Pealc Horizontal Ground Acceleration (g) Peak Horizontal Ground Acceleration (g) Rose Canyon 5.0 1.5 7.2 0.34 0.26 Newport-Inglewood (Offshore) 6.0 1.5 7.1 0.29 0.26 Coronado Bank 21.1 3.0 7.6 0.16 0.26 Elsinore 24.1 5.0 7.1 O.U 0.26 Notes: * CDMG, 1996. The maximum earthquake is defined by the State of California as the maximum earthquake that appears capable of occurring under the presently understood tectonic fi-amework. Site-specific seismic parameters included in Table 1 are the distances to the causative faults, earthquake magnitudes (Mw), and expected ground accelerations, which were determined with EQFAULT software (Blake, 2004a). As indicated in Table 1, the Rose Canyon Fault is the active fault considered to have the most significant effect at the site fi-om a design standpoint. The maximum earthquake from the fault has a 7.2 moment magnitude, generating a peak horizontal groxmd acceleration of 0.34g at the project site. Secondary effects associated with severe ground shaking following a relatively large earthquake on a regional fault that may affect the site include ground lurching and shallow ground rupture, soil liquefaction and dynamic settlement, seiches and tsunamis. These secondary effects of seismic shaking are discussed in the following sections. -6- C:\Active\ Piojects\2007\2007-0020 - Courtney Adams Condos\Final ReportWIP Partners Adams Reportdoc GeoLogic Associates From a probabilistic standpoint, the design ground motion (per UBC, 1997/CBC, 2001) is defined as the ground motion having a 10 percent probability of exceedance in 50 years (475-year retum period). This ground motion is referred to as the design earthquake. The design earthquake ground motion at the site is predicted to be 0.26g. The effect of seismic shaking may be mitigated by adhering to the Uniform Building Code and state-of-the-art seismic design parameters of the Stractural Engineers Association of California. The site is located within Seismic Zone 4 (UBC, 1997/CBC 2001, Figure 16-2). 4.2.1 Lurching and Shallow Ground Rupture Soil lurching refers to the rolling motion on the ground surface by the passage of seismic surface waves. Effects of this nature are likely to be significant where the thickness of soft sediments vary appreciably under stmctures. Damage to the proposed development should not be significant since a relatively large differential thickness of surficial materials does not exist at the site. 4.2.2 UBC Criteria The site soil parameters in accordance with UBC 1997/CBC, 2001 are as follows: Seismic Zone = 4 (Figure 16-2; UBC, 1997 /CBC, 2001) Soil Profile Type = So (Table 16-J; UBC, 1997/CBC, 2001) Slip Rate (Rose Canyon Fault), SR, (Table 16-U) = 1.5nim per year (CDMG, 1996) Seismic Source Type (Table 16-U, UBC, 1997/CBC, 2001) = B Na = 1.0 (Table 16-S; UBC, 1997, CBC, 2001) Nv = 1.1 (Table 16-T; UBC, 1997, CBC, 2001) 4.23 Historical Seismicity The historic record of earthquakes in southern California for the past 200 years has been reasonably well established. More accurate instrumental measurements have been available since 1933. Based on recorded earthquake magnitudes and locations, the area may be vulnerable to moderate seismic ground shaking during the design life of the project. 4.2.4 Liquefaction and Dynamic Settlement Liquefaction is a phenomenon in which soils lose shear stiength for short periods of time during an earthquake, which may result in very large total and/or differential settiements for stmctures -7- C:\Active\_Projects\2007\2007-0020 - Courtney Adams Condos\Final ReportWIP Partners Adams Reportdoc GeoLogic Associates founded on liquefying soils. In order for the potential effects of liquefaction to be manifested at the ground surface, the soils generally have to be granular, loose to medium dense, saturated relatively near the ground surface, and must be subjected to a sufficient magnitude and duration of shaking. Since the stmcture will be founded on competent materials of the Santiago Formation, the potential for large-scale liquefaction effects to the proposed surface improvements is low. It should also be understood that much of Southern Cahfomia is an area of moderate to high seismic risk and is not generally considered economically feasible to build stmctures totally resistant to earthquake related hazards. However, current state-of-the-art standards for design and constmction are intended to reduce the potential for major stmctural damage. Evaluation of liquefaction effects underljdng the boat house in not within the scope of this report. 4.2.5 Ground Surface Rupture Since no active faults are known to tiansect the site, ground surface mpture as a result of movement along known faults is considered unlikely. 4.2.6 Landslides The site is located in a sloping area with favorable geologic stmcture and rock types. Accordingly, the potential for landslides or other slope instability problems is considered low. 4.2.7 Tsunamis and Seiches A tsunami (incorrectly called a tidal wave) is a sea wave generated by submarine earthquakes, landslides or volcanic activity which displaces a relatively large volume of water in a very short period of time. Several factors at the originating point such as; earthquake magnitude, type of fault, depth of earthquake, focus, water depth, and the ocean bottom profile all contribute to the size and momentum of a tsunami (fida, 1969). In addition, factors such as the distance away from the originating point, coastline profile (including width of the continental shelf), and angle at which the tsunami approaches the coastline also affect the size and severity of a tsunami. There have been over 500 tsunamis reported with recorded history, most of them occurring within the Pacific Ocean, however, one of the largest tsunamis ever recorded (December 2004) recently occurred in the Indian Ocean as a result of a Magnitude 9.0 earthquake event This event was the fourth largest earthquake to occur in the world in the last 100 years (USGS, 2005b). Large tsimamis have been occurring somewhere in the Pacific Basin at an average rate -8- C:\Active\_Projecls\2007\2007-0020 - Courtney Adams Condos\FinaI ReportWIP Partners Adams Reportdoc GeoLogic Associates of roughly 1 every 12 years. Table 2 shows a number of great tsunamis representing each of the major generating zones within the Pacific Basin (Joy, 1968). Table 2 Major Tsunamis Recorded in San Diego County* San Diego La JoUa Event/Location Date Arrival Time (how) Wave Height (m) Arrival Time (hour) Wave Height (m) Prince William Sound, Alaska 3/27/64 +6.2 1.1 +5.8 0.7 Southern Chile 5/22/60 +14 1.4 +14 1.0 Aleutian Islands 3/9/57 +6.9 0.5 +6.6 0.6 Kamchatka 11/5/52 +9.6 0.7 +9.6 0.2 Aleutian Islands 4/1/46 ? 0.4 +6.2 0.4 Sanriku, Japan 3/3/33 ? Unknown ? 0.3 Cape Arguello, California** 11/24/27 ? 0.05 +0.98 0.05 * Joy, 1968 ** This is the only well documented locally generated tsunami in CaUfomia history. Tsunami wave heights and nmup elevations experienced along the San Diego area coastline during the last 170 years have fallen within the normal range of tidal fluctuations (approximately 9 feet). Southern California is oriented obliquely (i.e. not directly in line) with the major originating tsunami zones, it has a relatively wide and mgged continental shelf (or borderland) which acts as a diffuser and reflector of remotely generated tsunami wave energy (Joy, 1968). These conditions, in addition to the geologic and seismic conditions (such as the strike-slip fault regime, and the scarcity of large submarine earthquakes) along the coastline also tend to minimize the likelihood of a large tsunami at the site. The USC Tsunami Research Group is currently working on a series of tsunami inundation maps for southem California (USC, 2005). The site is within the Agua Hedionda Lagoon and tsunami predictions have not been found in the literature. It is likely that the potential for significant tsunami effects in the lagoon are relatively low since the site is protected from direct wave action, however, the tsunami wave height may be dampened or amplified by the confines of the lagoon. Data from coastal studies will be presented since the effects of wave heights in the lagoon are not well understood. -9- C;\Active\ Projects\2007\2007-0020 - Courtney Adams CondosWinal ReportWIP Partners Adams Report.doc GeoLogic Associates McCuUough (1985) predicts the average tsunami height in the San Diego region for an event with a 10% probability of exceedence in 50 years (approximately 500-year retum period) is approximately +13 to +15 feet mean sea level. Work by Garcia and Houston (1974) presents a similar 500-year retum period wave height ranging from +11 to +13 feet mean sea level. Based on these reports and the finish floor elevation (parking level) of 8 feet mean sea level, the site is below the 500-year retum period tsunami wave height. Garcia and Houston (1974) calculates the 100-year retum period wave height at approximately 6 feet which coupled with a maximum high tide elevation of 5 feet mean sea level, is roughly 3 feet above the lowest finish (parking level) floor. Accordingly, based on the above data, there is a moderate to high potential for tsunami or storm surge waves at the site ^ the parking level, but not within the Hii*ing li^i^ (assuming that the tsimami energy is not dampened by entering the lagoon). Seiches are defined as oscillations in a semi-confined body of water (such as a lake or lagoon) due to earthquake shaking or fault mpture. Seiches with a wave height on the order of tsunami wave heights may also affect the site. 4.2.8 Flooding I the maximum high tide level of 4.9 feet mean sea level and the site^levation of 8 fe^ urge of over 3+ feet will be necessary to flood the iBS^'^^iC ^"f^^otential for a storm Based on a storm surge of over 3+ feet will be necessary to flood the feSSlfy flfli "TTie'potential surge greater than 3 feet is low to moderate. The potential is further reduced by the limited likelihood of the storm surge occurring at the same time as the asfronomical high tide event and the dampening effects of the lagoon. 4.2.9 Expansive Soils Samples of the near-surface fill soils were collected from the borings. The results indicate that the expansion potential of the soils to be exposed at the lowest garage level is in the low range (based on ASTM D4829). The expansion test results are presented in Appendix B. -10- C;\Active\ Projects\2007\2007-0020 - Courtney Adams Condos\FinaI ReportWIP Partners Adams Reportdoc GeoLogic Associates 5.0 CONCLUSIONS Based on the results of our geotechnical review of the site, it is our opinion that the proposed development is feasible from a geotechnical standpoint, provided the following conclusions and recommendations are incorporated into the project plans and specifications. The following is a summary of the geotechnical factors that may affect development of the site. • An excavation (on the order of 40+ feet) is necessary to reach the lowest proposed garage floor level. Tie-back shoring is anticipated due to the limited horizontal distance from the street to northem wall of the garage. After the excavation is completed, the stmcture is anticipated to be foimded on competent materials of the Santiago Formation. The saturated foundation materials in a limited area in the extieme southem portion of the garage may need to be removed and recompacted using dewatering techniques or the materials maybe "bridged" with a stmctural (self-supporting) floor slab. All the footings of the stmcture should be deepened to be founded in the Santiago Formation. This may necessitate deeper footings along the southem wall of the stmcture. • In general, the existing onsite soils appear to be suitable material for stmctural fill constmction provided they are relatively free of organic material, debris, and rock fragments larger than 6 inches. The onsite fill and colluvium soils should be removed (down to competent material) and recompacted prior to placement of fill soils or improvements. Removals may range up to 9+ feet and locally be greater. Fill soils should be removed and recompacted to a minimum 90 percent relative compaction. • Based on our subsurface exploration and laboratory testing, the proposed pad grade soils are generally considered to have a very low to low expansion potential (Appendix B) and a negligible potential for sulfate attack on concrete. The onsite soils are considered to have a very high potential for corrosion to buried uncoated metal conduits. • The site is not in an area of known active faults. The potential for geologic hazards to significantly affect the proposed constmction is low. The design earthquake, having a 10 percent probability of being exceeded in 50 years, is expected to produce a peak ground surface acceleration at the site of 0.26g. The garage floor level may be affected by tsunamis or flooding during the project lifetime. • Groundwater/seepage was encountered at a depth of 7.5 feet (elevation of 3.5 feet mean sea level) in Boring B-3. The groundwater level will fluctuate seasonally, and considering the time of year and the last few years of below average precipitation, the groundwater table at -11- C:\Active\ ProjectsV2007\2007.O020 - Courtney Adams CondosVFinal ReportWIP Partners Adams Reportdoc GeoLogic Associates the time of constmction will likely be higher. Groundwater/seepage will likely be encountered during excavation/recompaction at the southem portion of the site and special constmction dewatering techniques may have to be employed to confrol groundwater seepage during the anticipated removals especially at the southem portion of the parking level. 6.0 RECOMMENDATIONS 6.1 General Earthwork Earthwork should be performed in accordance with the project specifications and the following recommendations. 6.1.1 Site Preparation Prior to grading, the site should be cleared of existing surface/subsurface obstmctions, septic systems, foundations, stmctures, etc. Vegetation, oversize material, and debris should be disposed off site. Holes resulting from removal of buried obstmctions such as foundations or below-grade stmctures that extend below finished site grades should be filled with properly compacted soil under the observation and testing of the geotechnical engineer. 6.1.2 Removals and Treatment of Transition Condition Since the existing fill and colluvium soils were observed to be dry, loose, and have small pores, we recommend that the fill soils and colluvium be removed down to competent material (where otherwise not removed by the proposed excavation), moisture-conditioned, and recompacted prior to the placement of stmctural fills or the proposed site improvements. Removals may range up to 9 feet and may be locally deeper. Where these removals occur adjacent to the property lines, shoring may be necessary. All excavation/removal bottoms should expose firm and competent formational materials and be observed by a representative of the geotechnical engineer. To reduce the potential for differential settlement due to a tiansition (cut/fill) condition, we recommend that all the footing be founded into the Santiago Formation. The fill/colluvial soils in the southem portion of the site should be removed and recompacted and recompacted to a minimum relative compaction of 90%. This removal should extend a minimum of 5 feet (but at least equal to the depth of the removals) beyond the building perimeter and all settlement- sensitive stmctures. Dewatering may be necessary in selected areas to facilitate constmction and aid in recompaction. As an altemative, the soils may be left in their current condition and a - 12- C:\Active\_Projects\2007\2007-0020 - Courtney Adams Condos\Final ReportWIP Partners Adams Report.doc GeoLogic Associates deepened footing (or pier and grade beam supported footing) with a stmctural (self-supporting) slab may be designed to "bridge" these soils. Flatwork and other improvements in this area should also be designed with a deepened footing or be designed to be "floating". 6.1.3 Structural FiUs The onsite soils are generally suitable for use as compacted fill provided they are free of organic material and debris. Material greater than 6 inches in maximum size should not be placed within 5 feet of the pad grade. Asphalt concrete and concrete should not be placed in stmctural fills. The area to receive fill should be scarified to a minimum depth of 6 inches, brought to near optimum moisture content, and recompacted to at least 90 percent relative compaction (based on Modified Proctor, ASTM D1557). Fill soils should be placed at a minimum of 90 percent relative compaction (based on Modified Proctor, ASTM D1557) near optimum moisture content. The optimum lift thickness to produce a uniformly compacted fill will depend on the type and size of compaction equipment used. In general, fill should be placed in uniform lifts not exceeding 8 inches in thickness. All import soils should have an expansion index less than 20 (per ASTM D4829). These soils should be tested by the geotechnical consultant prior to site delivery for conformance to the above recommendations. Fills placed within 5 feet of finish pad grade should consist of soils with an expansion potential less than 20 based on UBC Standard 18-2 (ASTM D4829) and with a maximum particle size less than 6 inches. 6.1.4 Trench BackfiU The onsite soils may generally be suitable as tiench backfill provided they are screened of rocks and other material over 6 inches in diameter and organic matter. Trench backfill should be compacted in uniform lifts (not exceeding 8 inches in compacted thickness) by mechanical means to at least 90 percent relative compaction (ASTM D 1557). 6.2 Foundation Design It is assumed that soil with a low expansion potential (less than 50 per ASTM D4829) will be exposed at the proposed garage level subgrade. Therefore, for design purposes, we provide the following foundation design parameters based on a low expansion potential. -13- C:\Active\ Projects\2007\2007-0020 - Courtney Adams Condos\Final ReportWIP Partners Adams Report.doc GeoLogic Associates Footings bearing in properly compacted fill should have a minimum depth of 24 inches below the lowest adjacent compacted soil grade. At a depth of 24 inches, footings may be designed using an allowable soil-bearing value of 3,500 pounds per square foot (psf). At a depth of 30 inches, an allowable bearing capacity of 4,000 psf may be used. These values may be increased by one- third for loads of short duration including wind or seismic forces. Continuous and isolated-spread footings shall have a minimum base dimension no less than 18 inches and 24 inches, respectively and should be reinforced in accordance with the recommendations of the stmctural engineer and the latest edition of the Uniform Building Code/CBC. Continuous footings should have minimum reinforcement of four No. 5 rebars; two near the top and two near the bottom of the footing. Stmctural requirements may necessitate greater reinforcement. If founded near the top of slopes, footings, as well as retaining stmctures should have a minimum 10-foot setback (measured horizontally) from the base of the footing to daylight. Our preliminary foundation design recommendations are summarized in Table 3 below: Table 3 — Foundation Design Recommendation Summary Minimum Depth: 24 inches below lowest adjacent soil grade (minimum) Minimum Width: 18 inches Continuous Reinforcement: Four No. 5 rebars (2 near top and 2 near bottom) mm Footings: Slope Setback: 10-foot minimum Allowable Bearing Capacity: 3,500 psf (at 24 inches deep), 4,000 psf (at 30 inches deep) Minimum Depth: 24 inches below lowest adjacent soil grade (minimum) mm Minimum Width: 24 inches Isolated Spread Reinforcement: Per structural engineer Footings: Slope Setback: 10-foot minimum Allowable Bearing Capacity: 3,500 psf (at 24 inches deep), 4,000 psf (at 30 inches deep) MM Garage Slab-on-Minimum Thickness: 5 inches Grade Floor: Minimimi Reinforcement: No. 4 rebars at 18 inches on center (each way) m Design Settlement See Section 6.4 Garage slabs should have a minimum thickness of 5 inches. If heavy tmck or RV loads are anticipated, the slab thickness may be increased based on actual design by the stmctural engineer to accommodate these greater loads. Minimum slab reinforcement should consist of No. 4 bars at 18 inches on center (each way). We emphasize that it is the responsibility of the contiactor to ensure that the slab reinforcement is placed at slab mid-height. Slabs should be underlain by a 2- inch layer of sand (SE minimum of 30) to aid in concrete curing and to act as a capillary break. - 14 - C:\Active\ Projects\2007\2007-0020 - Courtney Adams Condos\Final ReportWIP Partners Adams Report,doc GeoLogic Associates which is underlain by a 6-mil (or heavier) moisture barrier (to reduce the potential for formation of salt crystals or white efflorescence). The moisture barrier should be underlain by an additional 2-inch layer of clean sand to protect the moisture barrier. All penetiations through the moisture barrier and laps should be sealed. Since the garage level has the potential for inundation by water, a method to remove accumulated water may be pmdent. Our experience indicates that use of reinforcement in slabs and foundations can generally reduce the potential for drying and shrinkage cracking. However, some cracking should be expected as the concrete cures. Minor cracking is considered normal; however, it is often aggravated by a high water/cement ratio, high concrete temperature at the time of placement, small nominal aggregate size, and rapid moisture loss due to hot, dry, and/or windy weather conditions during placement and curing. Cracking due to temperature and moisture fluctuations can also be expected. The use of low slump concrete (not exceeding 4 inches at the time of placement) can reduce the potential for shrinkage cracking. Moisture barriers can retard, but not eliminate vapor movement from the underlying soils up through the slab. In living areas, we recommend that the floor-covering contractor test the moisture vapor flux rate prior to attempting application of moisture-sensitive flooring. 'Breathable' floor covering or special slab sealants should be considered if the vapor flux rates are high. Floor covering manufacturers should be consulted for specific recommendations. If tile or other crack or movement-sensitive flooring is planned, a slipsheet should be used. Flexible joint material should be used where crack-sensitive flooring overlies concrete joints. 6.3 Moisture Conditioning The upper 12 inches of subgrade soils underlying conventionally reinforced foundation systems and exterior flatwork should be brought to at least optimum moisture content prior to placement of the moisture barrier and slab concrete. This should be checked by the soil technician prior to concrete placement. 6.4 Settlement The recommended allowable bearing capacity is generally based on a total static settlement of one inch. Differential (static) settlement is likely to be approximately one-half of the total settlement occurring shortly after application of the building loads. -15- C:\Active\ Ptojects\2007\2007-0020 - Courtney Adams Condos\FinaI ReportWIP Partners Adams Reportdoc GeoLogic Associates 6.5 Lateral Earth Pressures and Resistance Embedded stiaxctural walls should be designed for lateral earth pressures exerted on them. The magnitude of these pressures depends on the amount of deformation tiiat the wall can withstand under load. If the wall can yield enough to mobilize the full shear stiength ofthe soil, it can be designed for "active" pressure. If the wall cannot yield under the applied load, tfie shear stiength of tiie soil cannot be mobilized and the earth pressure will be higher. Such walls should be designed for 'at rest' conditions. If a stiucture moves toward the soils, the resulting resistance developed by the soil is the 'passive' resistance. For design purposes, the recommended equivalent fluid pressure in each case for walls founded above the static ground water table (with level backfill) and backfilled with gravel, onsite or import soils of low expansion potential (less than 50 per ASTM D4829) is presented in the following table. Table 4 - Lateral Earth Pressures Equivalent Fluid Weight (pcf) Condition Level 2:1 Slope Active 40 60 At-Rest 60 70 Passive 350 (Maximum of 3 ksf) - The above values assume free-draining conditions. If conditions other than those covered herein are anticipated, the equivalent fluid pressure values should be provided on an individual case basis by the geotechnical engineer. A surcharge load for a restiained or unrestiained waU resulting from automobile traffic may be assumed to be equivalent to a uniform pressure of 100 psf which is in addition to the equivalent fluid pressures given above. All retaining wall stiuctures should be provided witfi appropriate drainage and waterproofing. Wall backfiU should be compacted by mechanical methods to at least 90 percent relative compaction (based on ASTM Test Method D1557). Wall footing design and setbacks should be performed in accordance witii the previous foundation design recommendations and reinforced in accordance witii stiiictural considerations. Soil resistance developed against lateral sti-uctural movement can be obtained from the passive pressure value provided above. Further, for sliding resistance, a fiiction coefficient of 0.35 may be used at the concrete and soil interface. These values may be increased by one-third for loads of short duration including wind or seismic loads. The total resistance may be taken as the sum -16- C:\Active\_Proiects\2007\2007-0020 - Courtney Adams Condos\FinaI ReportWIP Partners Adams Report doc GeoLogic Associates of the frictional and passive resistance provided that the passive portion does not exceed two- thirds of the total resistance. 6.6 Slope Excavation and Shoring Slope excavations may be utilized when adequate space allows. Based on our borings and laboratory testing, we provide the following recommendations in Table 5 for sloped excavations in fill soils or competent formational materials without seepage conditions. Table 5 Temporary Excavation Slopes Excavation Depth (feet) Maximum Slope Ratio in Competent Bay Point or Santiago Formational Materials (Horizontal to Vertical) Maximum Slope Ratio in Existing Fill SoUs (Horizontal to Vertical) 0-3 Vertical 1:1 3-10 3/4:1 1:1 10-25 1:1 N/A Grreater than 25 1-1/2:1 N/A We do not recommend surcharge loading or equipment lay-down within five feet of the top of slope. Care should be taken during excavation adjacent to the existing stmctures so that undermining does not occur. Where fill/colluvium exists above formational materials, the "competent person" (as defined by OSHA) should observe the slope on a daily basis for signs of instability. If sufficient horizontal distance does not allow slope layback in accordance with Table 5, we recommend that slopes be retained either by a cantilever shoring system deriving passive support from cast-in-place soldier piles (lagging-shoring system) or a restrained tie-back and pile system. Lagging is recommended due to the friable nature of the soil. Based on our experience with similar projects, if lateral movement of the top of the shoring system on the order of one to two inches cannot be tolerated, we recommend the utilization of a restiained tie-back and pile system. Shoring of excavations of this size is typically performed by specialty contractors with knowledge of the San Diego County area soil conditions. We recommend that the shoring contiactor provide the excavation shoring design. Tie-back shoring may be designed in accordance with the lateral pressures presented below and graphicaUy illustiated in Figure 4. -17- C:\Active\_Projects\2007\2007-0020 - Courtney Adams Condos\FinaI ReportWIP Partners Adams Report doc GeoLogic Associates Tie-Back Shoring Svstem -At-Rest Pressure = Trapezoidal distribution of 25H, starting at 0 at the top of the distribution, increasing to 25H at 0.2H from the top ofthe wall, uniform at 25H until 0.2H from the base of the wall and then decreasing to 0 at the bottom of the wall. -Passive Pressure = equivalent fluid weight of400 pcf above the groundwater table and 200 pcf below the groundwater table, to a maximum value of 6,000 psf -H = Height of excavation, feet All shoring systems should consider adjacent surcharging loads. For design of tie-backs, we recommend an allowable concrete-soil bond sfress of2,500 psf of the concrete-soil interface area for grouted anchors. This value is based on a minimum 20-foot-long anchor beyond the active zone and thus should be considered only behind the 40-degree line (measured from the vertical) up from the base of the footing (Figure 4). This portion should also be used for calculating resisting forces. Tie-back anchors should be individually proof-tested to 150 percent of design capacity. Further details and design criteria for tie-backs can be provided as appropriate. Since design of retaining systems is sensitive to surcharge pressures behind the excavation, we recommend that this office be consulted if unusual load conditions are anticipated. Care should be exercised when drilling or excavating into the on-site soils since caving or sloughing of these materials is possible. Field testing of tie-backs and observation of soldier pile excavations should be performed during constmction. Settlement monitoring of adjacent sidewalks and stmctures should be considered to evaluate the performance of the shoring. Shoring of the excavation is the responsibility of the contractor. Extieme caution should be used to minimize damage to existing pavement, utiUties, and/or stmctures caused by settlement or reduction of lateral support. Piers should extend a minimum of five feet below the bottom of the proposed footings. The bearing capacity values in Section 6.2 may be used to design the piers. An allowable skin fiiction along the side of the pier of 300 pounds per square foot may also be used for pier design provided the area where the fiiction is calculated is a minimum of four feet below the base of the proposed footings. The pier spacing should be determined by the project stmctural engineer. Special sheathing and/or corrosion protection should be considered for the beams and tiebacks. 6.7 Soil Corrosivity In general, soil environments that are detrimental to concrete have high concentiations of soluble sulfates and/or pH values of less than 5.5. Table 19-A-4 of UBC, 1997 provides specific guidelines for the concrete mix-design when the soluble sulfate content of the soil exceeds 0.1 -18- C:\Active\_Projects\2007\2007-0020 - Courtney Adams Condos\Final ReportWIP Partners Adams Reportdoc GeoLogic Associates percent by weight or 1000 ppm. The results of our laboratory tests on representative soils from the site indicated a soluble sulfate content ranging from 74 to 613 indicating that the concrete should be designed in accordance with the Negligible Category of Table 19-A-4 of UBC, 1997. The test results also indicate a minimum resistivity ranging from 680 to 1,525 ohm-cm, which is considered to present very high corrosion potential to buried metals. The test results are provided in Appendix B. For the appropriate evaluation and mitigation design for other substances with potential influence from corrosive soils, a corrosion engineer may be consulted. 6.7 Pavement Design For driveways, a minimum concrete pavement thickness of 5 inches is recommended. For delivery areas, frash areas, and RV or heavy tmck tiaffic areas utilized by the deUvery tmcks, we recommend a minimum section of 7 inches of Portland cement concrete (P.C.C.) over 2 inches of Class 2 aggregate base. The P.C.C. in the above pavement sections should be provided with appropriate steel reinforcement and crack-control joints as designed by the project stmctural engineer. If sawcuts are used, they should be a minimum depth of 1/3 the slab thickness and made within 8 hours of concrete placement. We recommend that sections be as nearly square as possible. A concrete mix with a minimum 28-day stiength of 3,250 psi should be utilized. P.C.C, and Class 2 base materials should conform to and be placed in accordance with the latest revision of the California Department of Transportation Standard Specifications (Caltians) and American Concrete Institute (ACI) codes. In accordance with the Standard Specifications for Public Works Constmction "Greenbook", the upper 6 inches of subgrade soils should be moisture conditioned and compacted to at least 95 percent relative compaction based on ASTM Test Method D1557 prior to placement of aggregate base. The base layer should be compacted to at least 95 percent relative compaction as determined by ASTM Test Method D1557. Untieated Class 2 aggregate base should meet the four criteria of Section 26-1.02A of the most recent Caltrans specifications and the Greenbook standards. We recommend that the curbs, gutters, and sidewalks be designed by the civil engineer or stmctural engineer. We suggest contioi joints, at appropriate intervals, as determined by the civil or stmcture engineer, be considered. We recommend 6x6-6/6 welded-wire mesh reinforcement and a minimum thickness of 4 inches for sidewalk slabs. If pavement areas are adjacent to landscape areas, we recommend steps be taken to prevent the subgrade soils from becoming saturated. The upper 12 inches of subgrade soils underljdng exterior flatwork should be presoaked to a minimum depth of 12 inches below slab subgrade. Concrete swales should be designed in roadway or parking areas subject to concentiated surface mnoff. -19- C:\Active\_Pn)jects\20O7\2O07-O02O - Courtney Adams Condos\FinaI ReportWIP Partners Adams Report.doc GeoLogic Associates 7.0 CONSTRUCTION OBSERVATION, LIMITATIONS, AND PLAN REVIEW The conclusions and recommendations in this report are based in part upon data that were obtained from a limited number of observations, site visits, excavations, samples, and tests. The nature of many sites is such that differing geotechnical or geological conditions can occur within small distances and under varying climatic conditions. Changes in subsurface conditions can and do occur over time. Therefore, the findings, conclusions, and recommendations presented in this report can be reUed upon only if GLA has the opportunity to observe the subsurface conditions during grading and constmction of the project, m order to confirm that our preliminary findings are representative for the site. In addition, we recommend that this office have an opportunity to review the final grading and foundation plans in order to provide additional site-specific recommendations. This report has not been prepared for use by parties or projects other than those named or described above. It may not contain sufficient information for other parties or other purposes. This report has been prepared in accordance with generally accepted geotechnical practices and makes no other warranties, either express or implied, as to the professional advise or data contained herein. -20- C:\Active\_Projects\2007\2007-0020 - Courtney Adams Condos\FinaI ReportWIP Partners Adams Report.doc GeoLogic Associates P 8.0 REFERENCES li 1^ 1^1 Blake, Thomas F., 2004a, EQFAULT, Version 3.00, Deterministic Estimation of Peak Acceleration from Digitized Faults. J Blake, Thomas F., 2004b, FRISKSP, Version 4.00, Probabilistic Earthquake Hazard Analysis Using Multiple Forms of Ground-Motion-Attenuation Relationships. California Building Code, (CBC), 2001. CDMG, 1996, Probabilistic Seismic Hazard Assessment for the State of California, Open-File Report No. 96-08. Excel, 2007, Site Development Plan, Sheets Cl and C2, CT06-16. Garcia, A.W. and Houston, J.R., 1974, Tsunami Run-up Prediction for Southem California Coastal Communities, USA in Tsunami Research Symposium 1974; Royal Society of New Zealand, BuUetin 15. Hart, E. W., and Bryant, W. A., 1997, Fault- Ruptiire Hazard Zones in California, Alquist-Priolo Earthquake Fault Zonmg Act with Index to Earthquake Fault Zones Maps: CDMG Special Publication 42. lida, K., 1969, The Generation of Tsunami and the Focal Mechanism of Earthquakes in Tsunami in the Pacific Ocean; Proceeding of the Intemational Symposium on Tsimamis and Tsunami Research, University of Hawaii, East-West Center Press. Intemational Conference of Building Officials, 1997, Uniform Building Code. E Ishihara, K., 1985, "Stability of Natural Deposits during Earthquakes", Proceedings ofthe Eleventh Intemational Conference of Soil Mechanics and Foimdation Engineering, A. A. g Belkema Publishers, Rotterdam, Netherlands. Ishihara, K. and Yoshimine, M., 1992, "Evaluation of Settlements in Sand Deposits FoUowing Liquefaction of Sand Under Cyclic Stiesses", Soils and Foundations, Vol. 32, No. 1, pp. 173-188. 2 - 21 - C:\Active\_Pitijects\2007\2007-0020 - Courtney Adams Condo5\FinaI ReportWIP Partners Adams Report doc GeoLogic Associates Joy, J.W., 1968, Tsunamis and Their Occurrence Along the San Diego County Coast Prepared for the Unified San Diego County Civil Defense and Disaster Organization: Westinghouse Oceans Research Laboratory. McCullough, 1985, Evaluating Tsunami Potential, in Evaluating Earthquake Hazards in the Los Angeles Region: An Earth-Science Perspective, USGS Professional Paper 1360. Southem Cahfomia Earthquake Center (SCEC), 1999, Recommended Procedures for Implementation of DMG Special Publication 117, Guidelines for Analyzing and Mitigating Liquefaction in California, March 1999. Tan, S. S., and Kennedy, M. P., 1996, Geologic Maps of the Northwestern Part of San Diego County, California: CDMG Open-File Report 96-02, Plate 1. USC, 2005, website: http://www.usc.edu/dept/tsunamis/califomia/. U. S. Geological Survey (USGS), 1986, 7 Vi- Minute Topographic Series, San Luis Rey, Original 1975, photorevised 1986, map scale 1:24,000. U.S. Department of the Navy, 1969, Civil Engineering, DM-5. USGS, 2005a, website: http://earthquake.usgs.gov/recenteqsww/Ouakes/usslav.htm. USGS, 2005b, http://en.wikipedia.org/wiki/2004 Indian_Ocean_earthquake#Ouake_characteristics - 22 - C:\Active\_Projects\2007\2007-0020 - Courtney Adams Condos\Final ReportWIP Partners Adams Report.doc GeoLogic Associates tum; 1,000-meter U T M giid zone 11 i>i.igage.cDm] S Quads: San Luis ReyjCA EncinHas: 1000 REFERENCE: U.S.G.S. 7.5 Minute Topographic Series, San Luis Rey, 1968, Pliotorevised 1975. FIGURE 1 N i VICINITY MAP VIP PARTNERS 4509 ADAMS STREET CONDOMINIUMS CARLSBAD, CALIFORNIA GeoLogic Associates Geologists, Hydrogeologis-ts, and Engineers Draft Date Project No. JGF 2/2007 2007-0020 REFERENCE: EXCEL, 2007. SCALE: 1 INCH = APPROX. 30 FEET FIGURE 2 LEGEND 5 •4 APPROXIMATE LOCATION OF EXPLORATORY BORING APPROXIMATE LOCATION OF CROSS SECTION (FIGURE 3) N i BORING LOCATION MAP VIP PARTNERS 4509 ADAMS STREET CONDOMINIUMS CARLSBAD, CALIFORNIA GeoLogic Associates Geologists, Hydrogeotoglsts. and Engineers Draft JGF Date FEB 2007 Project No. 2007-0020 I BORING B-1 ROOF PATIO '=50,00 GARAGE FLOOR=8.00, TD=36.5' EXISTING GRADE PROPOSED LOWEST FINISH FLOOR TD=11.5' REFERENCE: EXCEL, 2007. FOR CROSS SECTION LOCATION, SEE FIGURE 2. SCALE: 1 INCH = APPROX. 14 FEET AT 11 X 17 INCH FORMAT ONLY 1 LEGEND APPROXIMATE LOCATION OF EXPLORATORY BORING WITH TOTAL DEPTH (TD) ^ *V« APPROXIMATE LOCATION OF GEOLOGIC CONTACT, QUIERIED WHERE UNCERTAIN ^ APPROXIMATE LOCATION OF SEEPAGE ENCOUNTERED DURING DRILLING Af Fill Soils Qt Terrace Deposits Qcol Colluvium Ts Santiago Formation FIGURES CROSS SECTION A-A' VIP PARTNERS 4509 ADAMS STREET CONDOMINIUMS CARLSBAD, CALIFORNIA GeoLogic Associates Draft Date JGF FEB 2007 Project No. 2007-0020 RECOMMENDED EARTH PRESSURES FOR SHORING Anchor resistance behind this line Tie-back T (4' MSL) Tie-Back Shoring Diagram Neglect upper one foot of passive pressure except where concrete or pavement exists Below groundwater table. FIGURE 4 VIP PARTNERS 4509 ADAMS STREET CARLSBAD, CALIFORNIA SHORING DESIGN GeoLogic Associates Geologists, Hydrogeologists, and Engineers DRAFT DATE JOBNA. JGF MARCH 2007 2007-0020 APPENDIX A BORING LOGS GeoLogic Associates Boring Log BORING NO.: B-1 PAGE 1 OF 1 JOB NO.: SITE LOCATION: DRILUNG METHOD: CONTRACTOR: LOGGED BY: 2007-0020 ADAMS STREET, CARLSBAD, CA 8" 0 HOLLOW STEM AUGER CAL PAC MOBIL B-53 T. PRIMAS DATE STARTED: 2/16/2007 DATE FINISHED: 2/16/2007 ELEVATION: 34.5 FEET (EXCEL. 2007) GW DEPTH; CAVING DEPTH; TOTAL DEPTH; NA NA 36.5 FEET 1 UJ 3 Si o (7) UJ X (J o z a. DESCRIPTION 105.7 123.8 8.8 10.3 123.6 10.1 20 18 68 38 32 44 51 40 75 BULK 2.5 1.4 2.5 1.4 1.4 1.4 2.5 1.4 BULK 1.4 10 11 --6 40 45 50 •10 ML TTEO TWO INCHES OF ASPHALT OVER MODERATE BROWN (SYR 4/4) MOIST, STIF, CLAYEY SILT. COLLUVIUM: PALE YELLOWISH BROWN (10YR 6/2) MOIST. STIFF CLAYEY SILT WITH CAUCHE VEINS. TERRACE DEPOSITS: DARK YELLOWISH ORANGE. MOIST. MEDIUM DENSE, RNE SILTY SAND WITH TRACE OF CLAY. SM SANTIAGO FORMATION: YELLOWISH GRAY (5Y 7/2) MOIST, VERY DENSE, SILTY SANDSTONE. ML YELLOWISH GRAY (5 Y 7/2) MOIST, VERY DENSE. ClAYEY SILTSrONL •12 •13 •14 •15 •16 NOTES: 1. TOTAL DEPTH = 36.5 FEET. 2. SAMPLER DRIVEN BY A 140-POUND HAMMER WITH A 30-INCH DROP. 3. NO GROUNDWATER ENCOUNTERED AT TIME OF DRILUNG. 4. BORING BACKnU£D WITH BENTONITE ON 2/16/07. The data presented on this log is a simplification of actual conditions encountered and applies only at the location of this boring and at the tinne of drilling. Subsurface conditions may differ at other locations and may change with the passage of time. GeoLogic Associates Boring Log BORING NO.: B-2 PAGE: 1 OF 1 JOB NO SITE LOCATION: DRIUJNG METHOD: CONTRACTOR LOGGED BY: 2007-0020 ADAMS STREET. CARLSBAD. CA 8" 0 HOLLOW STEM AUGER CAL PAC MOBIL B-53 T. PRIMAS DATE STARTED: 2/16/2007 GW DEPTH; DATE RNISHED: 2/16/2007 CAVING DEPTH; ELEVATION: 35.0 FEET (EXCEL. 2007) TOTAL DEPTH; NA NA 16.5 FEET H o --^ i| o y I a. < Sly Ul o Si |i 65 u. DESCRIPTION 62.5 6.6 126.1 8.5 29 22 36 36 41 BUU< 1.4 2.5 BUU< 1.4 2.5 BUU< 1.4 20 25 30 40 45 50 TOO TWO INCHES OF ASPHALT OVER DARK REDDISH BROWN (10YR 3/4) MOIST. LOOSE. SILTY SAND. TERRACE DEPOSITS: DARK REDDISH BROWN (10YR 3/4) MEDIUM DENSE. RNE SILTY SANDSTONE. 10 11 12 •13 •14 •15 •16 SANTIAGO FORMATION: YEU.OWISH GRAY (5Y 7/2) MOIST. DENSE, RNE SILTY SANDSTONE. NOTES: 1. TOTAL DEPTH = 16.5 FEET. 2. SAMPLER DRIVEN BY A 140-POUND HAMMER WITH A 30-INCH DROP. 3. NO GROUNDWATER ENCOUNTERED AT TIME OF DRILUNG. 4. BORING BACKRUID WITH SOIL ON 2/16/07. The data presented on this log is a simplification of actual conditions encountered and applies only at the location of this boring and at the time of drilling. Subsurface conditions may differ at other locations and may chonge with the passage of time. GeoLogic Associates Boring Log BORING NO.: B-3 PAGE: 1 OF 1 JOB NO SITE LOCATION; DRILUNG METHOD; CONTRACTOR; LOGGED BY; 2007-0020 ADAMS STREET. CARLSBAD. CA 8" 0 HOU.OW STEM AUGER CAL PAC MOBIL B-53 T. PRIMAS DATE STARTED: 2/16/2007 DATE RNISHED: 2/16/2007 ELEVATION: 11.0 FEET (EXCEU 2007) GW DEPTH; CAVING DEPTH; TOTAL DEPTH; NA NA 11.0 FEET uj => O UJ o z 0. I xtl £li! UJ o QO Si (oU. DESCRIPTION 107.9 118.4 9.2 12.4 13 8 10 24 BUU< 2.5 1.4 2.5 1.4 2 3 4 15 20 25 30 35 40 45 50 SC Tiili 2.5 INCHES OF ASPHALT OVER DUSKY YELLOWISH BROWN (10YR 2/2) MOIST. MEDIUM DENSE. RNE CLAYEY SAND. SC COU.UVIUM: DUSKY YEU.OWISH BROWN (10YR 2/2) MOIST. LOOSE. RNE CLAYEY SAND. 10 11 12 13 14 15 16 SM SANTIAGO FORMATION: YELLOWISH GRAY (5Y 7/2) MOIST. MEDIUM DENSE. RNE SILTY SANDSTONE. ^ NOTES: 1. TOTAL DEPTH = 11.5 FEET. 2. SAMPLER DRIVEN BY A 140-POUND HAMMER WITH A 30-INCH DROP. 3. NO GROUNDWATER ENCOUNTERED AT TIME OF DRIUJNG; SEEPAGE AT 7.5 FEET. 4. BORING BACKRU£D WITH BENTONITE ON 2/16/07. The data presented on this log is a simplification of actual conditions encountered and applies only at the location of this boring and at the time of drilling. Subsurface conditions may differ at other locations and may change with the passage of time. GeoLogic Associates Boring Log BORING NO.: B-4 PAGE: 1 OF 1 JOB NO. SITE LOCATION: DRIUJNG METHOD; CONTRACTOR; LOGGED BY; 2007-0020 ADAMS SFREET. CARLSBAD. CA 8" 0 HOLLOW STEM AUGER CAL PAC MOBIL B-53 T. PRIMAS DATE STARTED: 2/16/2007 GW DEPTH; DATE RNISHED: 2/16/2007 CAVING DEPTH; ELEVATION: 13.0 FEET (EXCEL. 2007) TOTAL DEPTH; NA NA 16.5 FEET II o u) in " Ul Ul _l a. I xb Eg o DESCRIPTION 4 4 6 31 BUU< 1.4 1.4 1.4 1.4 2 3 4 15 20 25 35 40 45 50 2.5 INCHES OF ASPHALT OVER DUSKY YELLOWISH BROWN (10YR 2/2) MOIST. VERY LOOSE. RNE CLAYEY SAND. COU.UVIUM: DUSKY YELLOWISH BROWN (10YR 2/2) MOIST. VERY LOOSE. RNE CLAYEY SAND. SANTIAGO FORMATION: YELLOWISH GRAY (5Y 7/2) MOIST. DENSE. RNE SILTY SANDSTONE. NOTES: 1. TOTAL DEPTH = 11.5 FEET. 2. SAMPLER DRIVEN BY A 140-POUND HAMMER WITH A 30-INCH DROP. 3. NO GROUNDWATER ENCOUNTERED AT TIME OF DRIUJNG. 4. BORING BACKRUiD WITH BENTONITE ON 2/16/07. •10 11 •12 •13 •14 •15 •16 The data presented on this log is a simplification of actual conditions encountered and applies only at the location of this twring and at the time of drilling. Subsurface conditions may differ at other locations and may change with the passage of time. APPENDIX B LABORATORY TESTING PROCEDURES AND TEST RESULTS APPENDIX B LABORATORY TESTING PROCEDURES AND TEST RESULTS Expansion Index Tests: The expansion potential of selected materials was evaluated by the Expansion hidex Test, U.B.C. Standard No. 18-2 (ASTM D4829). Specimens are molded under a given compactive energy to approximately the optimum moisture content and approximately 50 percent saturation or approximately 90 percent relative compaction. The prepared 1-inch thick by 4-inch diameter specimens are loaded to an equivalent 144 psf surcharge and are inundated with tap water until volumetric equilibrium is reached. The results of these tests are presented below: -Sample, Depth Sample Description Expansion Index Expansion Potential* -B-l/10,31'-33' Light olive gray fine to coarse sandy clay to clay sand (Santiago Fm) 23 Low - B-2/4, 5'-7' Orange brown fine sandy clay (Terrace Deposits) 32 Low B-3/1,0-2' Dark gray fine to medium sand (Fill) 0 Very Low * Based on the 1997 edition ofthe Uniform Building Code, prepared by the Intemational Conference of Building Officials, (UBS, 1997/CBC, 2001). Minimum Resistivitv and pH Tests: Minimum resistivity and pH tests were performed in general accordance with California Test Method 643. The results are presented in the table below: m Sample, Depth pH Minimum Resistivity (ohms-cm) Corrosion Potential** -B-l/10,31'-33' 8.2 1,525 Very High B-2/7, ll'-13' 7.6 680 Very High m B-3/1, 0-2' 8.4 1,350 Very High ** per City of San Diego Program Design Guidelines for Consultants, 1992, and US Navy, 1969. Direct Shear Testing: Relatively undisturbed samples fi-om the test pits were obtained in the sandier strata and direct shear testing was performed in accordance with ASTM D 3080. The results are presented as follows: Sample Location Friction Angle (Degrees) Cohesion^sf) B-1/4,7'-8' (Terrace Deposits) 37 400 C:\Active\_Projects\2007\2007-0020 - Courtney Adams Condos\Fiiial ReportWIP Partners Adams Report.doc B-1/8,25'-26' (Santiago Formation) 38 700 Soluble Sulfates: The soluble sulfate contents of a selected sample were determined by California Test Method 417. The test results are presented in the table below: Sample, Depth Soluble Sulfate Content (ppm) Sulfate Exposure*** m B-l/10,31'-33' 74 Negligible mm B-2/7,11'-13' 428 Negligible B-3/1, 0-2' 613 Negligible *** Based on the 1997 edition ofthe Uniform Building Code, Table No. 19-A.4, prepared by the Intemational Conference of Building Officials, (UBC, 1997/CBC, 2001). "R"-Value: The resistance "R"-value was determined by the California Materials Method No. 301. The selected sample was prepared and exudation pressure and "R"-value determined. The graphically determined "R"-value at exudation pressure of 300 psi is reported. Sample Location R-Value B-2/4, 5'-7' 34 B-2/7,11'-13' 5 C:\Active\_Projects\2007\2007-0020 - Courtney Adams Condos\Final ReportWIP Partners Adams Report.doc •R' VALUE CA 301 Project ViP Partners / Adams street Sample B-2/4 Soil Type Orange Brown, F.M. Sandy Clay Job No. 2002-017 By: LD Date 3/1/2007 mm TEST SPECIMEN A B C Grain Size Distribution m Compactor Air Pressure psi 160 55 80 Sieve As Rec'vd. {%Pass.) As Tested (%Pass.) mm Initial Moisture Content % 8.1 8.1 8.1 3" m Water Added ml 60 80 70 21/2" mm Moisture at Compaction % 13.5 15.3 14.4 2" m Sample & Mold Weight gms 3146 3150 3147 11/2" -Mold Weight gms 2114 2101 2106 1" Net Sample Weight gms 1032 1049 1041 3/4" Sample Height in. 2.47 2.531 2.502 1/2" Dry Density pcf 111.5 108.9 110.2 3/8" Pressure lbs 7170 2915 3960 #4 Exudation Pressure psi 571 232 315 #8 m Expansion Dial X 0.0001 31 10 20 #16 mm Expansion Pressure psf 134 43 87 #30 m Ph atlOOOIbs psi 28 50 39 #50 mm Ph at 2000lbs psi 57 117 85 #100 -Displacement turns 3.54 3.92 3.77 #200 R' Value 56 19 37 Sand Equivalent m Corrected 'R' Value 56 19 37 (CTM 217) FINAL "R" VALUE By Exudation Pressure {@ 300 psi): 34 By Epansion Pressure 36 Tl= 5 GeoLogic Associates 'R' VALUE OA 301 Project VIP Partners / Adams street Sample B-2/7 Soil Type Olive L. Brown, Clay (CH) / Sandy Clay Job No. 2002-017 By: LD Date 3/1/2007 TEST SPECIMEN A B C Grain Size Distribution Compactor Air Pressure psi 30 40 30 Sieve As Rec'vd. (%Pass.) As Tested (%Pass.) Initial Moisture Content % 6.0 6.0 6.0 3" Water Added ml 160 120 140 21/2" -Moisture at Compaction % 20.1 16.6 18.4 2" Sample & Mold Weight gms 3106 3187 3202 11/2" mm Mold Weight gms 2104 2109 2108 1" Net Sample Weight gms 1002 1078 1094 3/4" Sample Height in. 2.518 2.628 2.71 1/2" Dry Density pcf 100.4 106.6 103.3 3/8" Pressure lbs 2650 6360 4300 #4 Exudation Pressure psi 211 506 342 #8 Expansion Dial x 0.0001 0 10 3 #16 Expansion Pressure psf 0 43 13 #30 -Ph atlOOOIbs psi 95 80 90 #50 Ph at 2000lbs psi 160+ 145 155 #100 m Displacement turns -3.93 4.8 #200 R' Value <5 6 2 Sand Equivalent m Corrected 'R' Value <5 6 2 (CTM 217) FINAL "R" VALUE By Exudation Pressure (@ 300 psi): <5 By Epansion Pressure N/A Tl= 5 GeoLogic Associates Job No. 2007-020 DIRECT SHEAR TEST - ASTM D-3080 VIP Partners /Adams Street peak shear strength strength at 1/4" displacement 4000 3750 3500 3250 3000 2750 .,2500 OT _c2250 O) c <D2000 i_ -I—' CO Jo 1750 0) CO 1500 1250 1000 750 500 250 Sample 500 1000 1500 2000 2500 Normal Pressure (psf) Strain Rate: 0.0042 in. / min. 3000 3500 4000 B-1/4 Normal Pressure (psf) 1000 2000 4000 Type Description Undisturbed Sandy Clay & Saturated Drv Densitv (PCf) Initial Water Content i%) 123.8 10.3 Peak Shear Strength (psf) Ultimate Shear Strength (psf) 1130 @ 0.0600" 2140 (§) 0.0085" 3430(3)0.1050" 0= 400 psf ([)= 37 deg. 720 1380 2600 C = 100 psf (t) = 32 deg. GeoLogic Associates Job No. 2007-020 DIRECT SHEAR TEST - ASTM D-3080 ViP Partners /Adams Street 4000 3750 3500 3250 3000 2750 .,2500 OT Q. _c2250 +.* C3) c <D2000 CO 1750 0) CO 1500 1250 1000 750 500 250 Sample -1/8 peak shear strength strength at 1/4" displacement 500 1000 1500 2000 2500 Normal Pressure (psf) Strain Rate: 0.0042 in. / min. 3000 3500 4000 Type Description Undisturbed Sandy Clay & Saturated Drv Densitv fpcf) Initial Water Content (%) 123.6 10.1 Normal Pressure (psf) 1000 2000 4000 Peak Shear Strength (psf) Ultimate Shear Strength (psf) 1460(3)0.0575" 2340 @ 0.0840" 3820 @ 0.1020" 0= 700 psf (])= 38 deg. 760 1370 2690 C = 100 psf (^ = 33 deg. GeoLogic Associates APPENDIX C SEISMIC ANALYSIS CALIFORNIA FAULT MAP VIP Partners/Adams Street Condos 1100 1000 900 -- 800 -- 700 -- 600 -- 500 400 300 -- 200 -- 100 -- -100 -400 -300 -200 -100 0 100 200 300 400 500 600 75 -- 50 -- 25 -- 0 -- -25 -50 -- CALIFORNL\ FAULT MAP VIP Partners/Adams Street Condos 190 200 210 220 230 240 250 260 270 280 290 300 310 * EQFAULT * * * * Version 3.00 * DETERMINISTIC ESTIMATION OF PEAK ACCELERATION FROM DIGITIZED FAULTS JOB NUMBER: 2007-0020 DATE: 02-22-2007 JOB NAME: VIP Partners/Adams Street Condos CALCULATION NAME: Test Run Analysis FAULT-DATA-FILE NAME: C:\Program Files\EQFAULTl\CGSFLTE_2004.DAT SITE COORDINATES: SITE LATITUDE: 33.14 4 9 SITE LONGITUDE: 117.3261 SEARCH RADIUS: 100 mi ATTENUATION RELATION: 2) Boore et al. (1997) Horiz. - NEHRP C (520) UNCERTAINTY (M=Median, S=Sigma) : M Niimber 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: C:\Program Files\EQFAULTl\CGSFLTE_2004.DAT MINIMUM DEPTH VALUE (km): 0.0 EQFAULT SUMMARY DETERMINISTIC SITE PARAMETERS Page 1 ABBREVIATED FAULT NAME APPROXIMATE DISTANCE mi (km) ================================ ====. === ==== === ===== ====== ==== ====== ====== ROSE CANYON 5 • 0( 8 .1) 7 .2 0 .335 IX NEWPORT-INGLEWOOD (Offshore) 6 .0 ( 9 .7) 7 .1 0 .288 IX CORONADO BANK 21 • 1 { 33 .9) 7 6 0 .156 VIII ELSINORE (TEMECULA) 24 .1 ( 38 .8) 6 8 0 .093 VII ELSINORE (JULIAN) 24 .2 ( 38 .9) 7 1 0 .108 VII ELSINORE (GLEN IVY) 34 .4 ( 55 .4) 6 8 0 .070 VI SAN JOAQUIN HILLS 36 .2 ( 58 .2) 6 6 0 .074 VII tttMl PALOS VERDES 36 8 ( 59 .2) 7 3 0 .087 VII EARTHQUAKE VALLEY 43 1 ( 69 .4) 6 5 0 .051 VI SAN JACINTO-ANZA 46 8 ( 75 .3) 1 7 2 0 .069 VI m NEWPORT-INGLEWOOD (L.A.Basin) 47 0 ( 75 .7) 1 7 1 0 .065 VI SAN JACINTO-SAN JACINTO VALLEY 47 5 ( 76 .4)1 6 9 1 0 .058 VI .mm CHINO-CENTRAL AVE. (Elsinore) 48 0 ( 77 .2) i 6 7 1 0 .063 VI SAN JACINTO-COYOTE CREEK | 52 0 ( 83 .7) 1 6 6 1 0 .046 VI WHITTIER 1 52 2 ( 84 .0) 1 6. 8 1 0 .051 VI ELSINORE (COYOTE MOUNTAIN) | 57 2 ( 92 .0) 1 6. 8 1 0 .048 VI mm SAN JACINTO-SAN BERNARDINO | 60 5 ( 97 .3) 1 6. 7 1 0 .043 1 VI m PUENTE HILLS BLIND THRUST | 62 4 ( 100 .5) j 7. 1 1 0 .063 1 VI SAN JACINTO - BORREGO j 65 6 ( 105 . 6) 1 6. 6 1 0 .039 1 V SAN ANDREAS - San Bernardino M-l| 66 1 ( 106 .4) 1 7. 5 1 0 062 1 VI SAN ANDREAS - Whole M-la | 66. 1 ( 106 .4)1 8. 0 1 0 080 1 VII m SAN ANDREAS - SB-Coach. M-lb-2 | 66. 1 ( 106 .4) 1 7. 7 1 0 068 1 VI SAN ANDREAS - SB-Coach. M-2b | 66. 1 ( 106 .4)1 7. 7 1 0 068 1 VI mm SAN JOSE 1 69. 0 ( 111 .1)1 6. 4 1 0 041 1 V CUCAMONGA j 71. 1 ( 114 .5) 1 6. 9 1 0 052 1 VI <m SIERRA MADRE | 71. 7 ( 115 .4) 1 7. 2 1 0 060 1 VI PINTO MOUNTAIN | 72. 0 ( 115 .8) 1 7. 2 1 0 049 1 VI SAN ANDREAS - Coachella M-lc-5 | 73. 1 { 117 .6) 1 7. 2 1 0 049 1 VI m NORTH FRONTAL FAULT ZONE (West) | 75. 1 ( 120 9) 1 7. 2 1 0 058 j VI BURNT MTN. | 76. 9 ( 123 7) 1 6. 5 1 0 032 1 V •mm. UPPER ELYSIAN PARK BLIND THRUST | 77. 9 ( 125 4) 1 6. 4 1 0 037 1 V CLEGHORN | 78. 2 ( 125 8) 1 6. 5 1 0 032 1 V SAN ANDREAS - 1857 Rupture M-2a | 79. 7 ( 128 3) 1 7. 8 1 0. 062 1 VI SAN ANDREAS - Cho-Moj M-lb-1 | 79. 7 ( 128 3) 1 7. 8 1 0. 062 1 VI SAN ANDREAS - Mojave M-lc-3 | 79. 7 ( 128 3) 1 7. 4 1 0. 050 1 VI m NORTH FRONTAL FAULT ZONE (East) | 80. 1 ( 128 9) 1 6. 7 1 0. 042 1 VI EUREKA PEAK | 80. 1 ( 128 9) 1 6. 4 1 0. 030 1 V •mm RAYMOND 1 80. 2 { 129 0) 1 6. 5 1 0. 038 1 V CLAMSHELL-SAWPIT I 81. 1 ( 130 5) 1 6. 5 1 0. 038 1 V m SUPERSTITION MTN. (San Jacinto) | 81. 9( 131. 8) 1 6. 6 1 0. 032 1 V ESTIMATED MAX. EARTHQUAKE EVENT MAXIMUM EARTHQUAKE MAG.(Mw) PEAK SITE ACCEL. EST. SITE INTENSITY MOD.MERC. DETERMINISTIC SITE PARAMETERS Page 2 APPROXIMATE 40 ABBREVIATED | DISTANCE MAXIMUM PEAK 1 EST. SITE FAULT NAME | mi (km) EARTHQUAKE SITE 1 INTENSITY MAG.(Mw) ACCEL, g 1 MOD.MERC. •• VERDUGO 1 83.3( 134 . 0) 6.9 0.046 1 VI HOLLYWOOD I 85.3( 137. 2) 6.4 0.034 1 V <m ELMORE RANCH I 85.5 ( 137. 6) 6.6 0.031 1 V •Mm SUPERSTITION HILLS (San Jacinto)| 86. 6 ( 139. 3) 6.6 0.031 1 V Wm LANDERS 1 87.4 ( 140. 6) 7.3 0.045 1 VI LAGUNA SALADA I 88.4 ( 142. 3) 7.0 0.038 1 V HELENDALE - S. LOCKHARDT | 88.7 ( 142. 8) 7.3 0.044 1 VI m SANTA MONICA j 89.5( 144. 0) 6.6 1 0.037 1 V LENWOOD-LOCKHART-OLD WOMAN SPRGS| 92. 6 ( 149. 0) 7.5 1 0.047 1 VI •mi MALIBU COAST I 92.8 ( 149. 4) 6.7 1 0.038 1 V BRAWLEY SEISMIC ZONE | 94.7 ( 152. 4) 6.4 0.026 1 V m JOHNSON VALLEY (Northern) j 95.1 ( 153. 0) 6.7 j 0.030 1 V EMERSON So. - COPPER MTN. | 96.1 ( 154. 7) 7.0 1 0.035 1 V <«• SIERRA MADRE (San Fernando) i 96.3( 154 . 9) 6.7 1 0.037 1 V m NORTHRIDGE (E. Oak Ridge) | 96.5 ( 155. 3) 7.0 1 0.043 1 VI SAN GABRIEL I 98.1( 157. 8) 7.2 1 0.039 1 V ANACAPA-DUME I 98.2 { 158. 0) 7.5 1 0.055 1 VI m -END OF SEARCH- 57 FAULTS FOUND WITHIN THE SPECIFIED SEARCH RADIUS. ESTIMATED MAX. EARTHQUAKE EVENT THE ROSE CANYON FAULT IS CLOSEST TO THE SITE. IT IS ABOUT 5.0 MILES (8.1 km) AWAY. LARGEST MAXIMUM-EARTHQUAKE SITE ACCELERATION: 0.3354 g m PROBABILITY OF EXCEEDANCE BOORE ET AL(1997) NEHRP C (520)1 100 25 yrs 50 yrs 75 yrs 100 yrs 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 Acceleration (g) PROBABILITY OF EXCEEDANCE BOORE ET AL(1997) NEHRP C (520)2 100 25 yrs 50 yrs 75 yrs 100 yrs 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 Acceleration (g)