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HomeMy WebLinkAboutCT 05-12; Ocean Street Residences; Tentative Map (CT) (9)GEOTECHNICAL INVESTIGATION OCEAN STREET CONDOMINIUMS OCEAN STREET AND MOUNTAIN VIEW DRIVE CARLSBAD, CALIFORNIA PREPARED FOR 2303 INVESTORS LP LA JOLLA, CALIFORNIA ' 0 2005 SEPTEMBER 3, 2004 GEOCON INCORPORATED GEOTECHNICAL CONSULTANTS Project No. 07353-22-01 Septen:iber 3,2004 2303 Investors LP 1020 Prospect Street, Suite 314 La Jolla, Califomia 92037 Attention: Ms. Christine Stanley Subject: OCEAN STREET CONDOMINrUMS OCEAN STREET AND MOUNTAIN VIEW DRIVE CARLSBAD, CALIFORNIA GEOTECHNICAL INVESTIGATION Dear Ms. Stanley: In accordance with your autliorization of our Proposal No. LG-04289 dated June 24, 2004, we are submitting the results of our Geotechnical Investigation for the subject site. The accompanying report presents the findings and conclusions from our study. Based on the results of our study, it is our opinion that the subject site can be developed as proposed, provided the recommendations of this report are followed. Should you have any questions regarding this investigation, or if we may be of further service, please contact the undersigned at your convenience. Very truly yours, GEOCON INCORPORATED Kenneth E. Cox RCE 65804 KEC:JJV:GWC:dmc (6) Addressee G^rryW., Cannon RCE 56468 6960 Flanders Drive B San Diego, California 92121-2974 B Telephone (858) 558-6900 • Fax (858) 558-6159 TABLE OF CONTENTS 1. PURPOSE AND SCOPE 1 2. SITE AND PROJECT DESCRIPTION I 3. SOIL AND GEOLOGIC CONDTTIONS 2 3.1 Undocumented Fill and Alluvium, Undifferentiated (Qudf/Qal) 2 3.2 Terrace Deposits (Qt) 2 4. GROUNDWATER 3 5. GEOLOGIC HAZARDS 3 5.1 Faulting and Seismicity 3 5.2 Soil Liquefaction Potential 4 5.3 Landslides 5 5.4 Tsunamis and Seiches 5 6. CONCLUSIONS AND RECOMMENDATIONS 6 6.1 General 6 6.2 Soil and Excavation Characteristics 6 6.3 Seismic Design Criteria 7 6.4 Mitigation of Liquefaction 7 6.5 Grading 8 6.6 Excavation Slopes, Shoring, and Tiebacks 10 6.7 Permanent Slopes 11 6.8 Foundation Recommendations 12 6.9 Deep Foundations 13 6.10 Concrete Slabs 15 6.11 Retaining Walls and Lateral Loads 16 6.12 Preliminary Pavement Section 17 6.13 Drainage 18 6.14 Grading and Foundation Plan Review 19 LIMITATIONS AND UNIFORMTTY OF CONDTTIONS MAPS AND ILLUSTRATIONS Figure 1, Vicinity Map Figure 2, Geologic Map Figures 3-5, Geologic Cross-Sections Figure 6, Wall/Column Footing Detail Figure 7, Retaining Wall Drainage Detail APPENDDC A FIELD INVESTIGATION Figures A-1 - A-10, Logs of Borings TABLE OF CONTENTS (Continued) APPENDK B LABORATORY TESTING Table B-1, Summary of Laboratory Direct Shear Test Results Table B-II, Summary of Laboratory Expansion Index Test Results Table B-IH, Summary of Laboratory Maximum Dry Density and Optimum Moisture Content Tests Results Table B-IV, Summary of Laboratory Resistance Value Test Results Table B-V, Summary of Laboratory pH and Resistivity Test Results Table B-VI, Summary of Laboratory Water-Soluble Sulfate Test Results Figure B-1, Gradation Curves Figures B-2 and B-3, Consolidation Curves APPENDIX C RECOMMENDED GRADING SPECIFICATIONS LIST OF REFERENCES GEOTECHNICAL INVESTIGATION 1. PURPOSE AND SCOPE This report has been prepared for the proposed condominiums to be located on the north side of Ocean Street, west of Mountain View Drive in Carlsbad, California (see Vicinity Map, Figure 1). The purpose of this investigation was to evaluate the surface and subsurface soil conditions, map general site geology, identify geotechnical constraints (if any) to the project, and provide recommendations relative to the geotechnical engineering aspects of proposed development. The scope of our investigation included a site reconnaissance, geologic mapping, review of aerial photographs, field investigation, laboratory testing, engineering analyses, and preparation of this report. Our scope also included a review of published geologic literature pertinent to the site. Our field investigation was performed on July 16 and 26 and August 27, 2004 and consisted of drilling and logging ten small-diameter borings. These borings were drilled to examine the soi! and geologic units and locate geologic contacts and features within areas of proposed development. Logs of the exploratory borings are presented in Appendix A. The approximate locations of the exploratory borings and site geology are plotted on Figure 2, Geologic Map. The geologic units encountered are also represented on the Geologic Cross-Sections, Figures 3 through 5. Laboratory tests were performed on selected soil samples obtained from the borings to determine pertinent physical properties for engineering analyses. Test results and a discussion pertaining to the laboratory testing are presented in Appendix B. The conclusions and recommendations presented herein are based on an analysis of the data obtained from the exploratory borings, laboratory tests, and our experience with similar soil and geologic conditions. 2. SITE AND PROJECT DESCRIPTION The subject site consists of developed land with apartment buildings and appurtenances located on the north side of Ocean Street and south of Buena Vista Lagoon. The property is bounded by a private drive to the east, apartments to the west, and Ocean Street to the south. Aerial photographs from 1953 indicate that the Buena Vista Lagoon once extended into the northem portion of the site. It is assumed that this land was reclaimed by placing hydraulic fill. Projecl No. 07353-22-01 - 1 - September 3, 2004 Surface elevations range from a low of approximately 12 feet above Mean Sea Level (MSL) on the northem side to a high of approximately 40 feet MSL at Ocean Street. Proposed development consists of the demolition of the existing apartments and mass grading of the site to enable construction of new condominiums with partially depressed parking structure. Final grading project plans are currently being developed; however, based on the existing topography, it is expected that cuts and fills of up to 15 and 10 feet, respectively, will likely be required to achieve finish grade on the pads. The above locations, descriptions and proposed development are based on a site reconnaissance and information provided by you. If development plans differ significantly from those described herein, Geocon Incorporated should be contacted for review and possible revision to this report. 3. SOIL AND GEOLOGIC CONDITIONS Soil conditions encountered during the field investigation included undocumented fill soil, alluvium, and Terrace Deposits. Each of these soil types is discussed below. 3.1 Undocumented Fill and Alluvium, Undifferentiated (Qudf/Qal) Undocumented fill soil and alluvium were encountered in Borings B3 and B5 through BIO. The fill consists of silty sand and sandy silt. The portion of the fill below the water table was likely placed with hydraulic fill methods. Shallow unmapped fills associated with the previous development are likely across the site. The fill is considered unsuitable in its present condition for the support of fill and/or structures and will require remediation as recommended in this report. Alluvium consists of silty and clayey sand and sandy silt. The alluvium is considered unsuitable in its present condition for the support of fill and/or structures and will require complete removal. The undocumented fill and alluvium are not differentiated on the Geologic Map and the Geologic Cross-Sections. 3.2 Terrace Deposits (Qt) Terrace Deposits were encountered in all of the borings, except boring B9, beneath the undocumented fill and the alluvium. This geologic unit is characterized as medium to very dense silty and clean sand and firm to hard clay and sandy silt. This unit should provide adequate support characteristics for proposed project development. Project No. 07353-22-01 - 2 - September 3,2004 4. GROUNDWATER Groundwater was encountered at a depth of 7 to 11.5 feet in borings B5 through B8 and BIO. This corresponds to an elevation of approximately 1 foot above Mean Sea Level (MSL). However, areas adjacent to the ocean generally have groundwater elevations of approximately 3 feet MSL. Any excavation that extends to approximately 3 feet MSL should expect to encounter groundwater. Groundwater is not expected to otherwise affect construcfion as presently proposed; however, it is not uncommon for groundwater or seepage conditions to develop where none previously existed. Therefore, proper surface drainage of rainfall and irrigafion water will be important to future perfonnance of the project. 5. GEOLOGIC HAZARDS 5.1 Faulting and Seismicity No active faults are known to exist at the site or in the immediate vicinity and none were encountered during our field investigation. The nearest known active fault is the Newport-lnglewood Fault located approximately 4.3 miles west of the site. The computer program EQFAULT(Blo-ke., 1989, updated 2000) was used to calculate the distances of known faults from the site. References used within the program in selecting faults to be included were Jennings (1975), Anderson (1984), and Wesnousky (1986). In addition to fault locafion, EQFAULT estimated peak ground accelerations at the site for maximum magnitude earthquakes. Attenuafion relationships presented by Sadigh, et al, (1997) were used to esfimate peak site acceleradons. Presented on Table 5.1 are the faults determined by the analysis to be most likely to subject the site to ground accelerafions. Project No, 07353-22-01 - 3 - September 3, 2004 TABLE 5.1 MAXIMUM EARTHQUAKE MAGNITUDE AND PEAK SITE ACCELERATIONS* Fault Name Approximate Distance From Site (miles) Estimated Maximum Earthquake Magnitude (Mw) Estimated Peak Site Acceleration (g) Newport-lnglewood (Offshore) 4 7.1 0.39 Rose Canyon Fault Zone 5 7.2 0.39 Coronado Bank 21 7.6 0.18 Elsinore-Temecula 24 6.8 0.10 Elsinore-Juiian 25 7.1 0.12 Elsinore-Glen Ivy 33 6.8 0.07 Palos Verdes 35 7.3 0.09 Earthquake Valley 45 6.5 0.04 Newport-lnglewood (L.A. Basin) 45 7.1 0.06 Chino-Central Avenue 47 6.7 0.05 San Jacinto-San Jacinto Valley 47 6.9 0.05 •^From £(2^4 [//.r Computer Program {Blake, 2000) The site could be subjected to moderate to severe ground shaking in the event of an earthquake on any of the above-referenced faults or other faults within the southem Califomia and northem Baja California region. With respect to this hazard, the site is considered comparable to others in the general vicinity. While listing peak accelerafions 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 morion and the soil conditions underlying the site. We recommend that seismic design of the structures be performed in accordance with the Uniform Building Code (UBC) guidelines that are currently adopted by the City of Carlsbad. 5.2 Soil Liquefaction Potential Soil liquefaction occurs within relatively loose, cohesionless sands located below the water table that are subjected to ground accelerations from earthquakes. The methodology of Youd, et al., (2001) was used to evaluate the potential for liquefaction. Based on the analysis, there is a high potenfial for liquefaction of an approximately 10 foot thick layer of silty sand and sandy silt within the undocumented fill and alluvium in the northem portion of the site. This layer of liquefiable material was observed in Borings B7, B8, and BIO. Manifestation of liquefaction at the ground surface is expected lo consist of approximately 3.5 inches of total settlement. Differential settlement is expected to be approximately half of the total setfiement, but may occur over relatively short distances. County topography maps indicate very little elevation difference between the northern portion of the site and the lagoon. Therefore, the potential for lateral Project No, 07353-22-01 -4-September3, 2004 spreading and flow slides is considered low. Mitigation of liquefaction settlement should consist of deep foundations or stone columns as discussed in subsequent secfions of this report. 5.3 Landslides Examination of aerial photographs in our files indicates that no landslides are present on the property or at a location that could impact the subject site. 5.4 Tsunamis and Seiches The site is located approximately 400 feet fi-om the ocean and adjacent to the Buena Vista Lagoon with a minimum elevation at the site of approximately 12 feet Mean Sea Level (MSL). Therefore, there is a moderate potenfial of a tsunamis or seiche inundating the site. Project No. 07353-22-01 - 5 - September 3, 2004 6. CONCLUSIONS AND RECOMMENDATIONS 6.1 General 6.1.1 It is our opinion that no soil or geologic conditions were encountered during the investigation that would preclude development of the property as planned, provided that the recommendations of this report are followed. 6.1.2 The northem portion of the site is underiain by up to 24 feet of undocumented fill and alluvium over dense Terrace Deposits. The southem portion of the site is underlain by dense Terrace Deposits with localized areas of shallow, undocumented fill. 6.1.3 Undocumented fill and alluvium are not considered suitable for the support of fill and/or structural loading in its present condition and will require remediation as outlined in this report. 6.1.4 Groundwater was encountered in Borings B5 through B7 at an elevation of approximately 1 foot MSL, but is generally encountered at approximately 3 feet MSL near the ocean. Groundwater and/or seepage-related problems are not expected. Surface drainage should be directed into properly designed drainage structures and away from pavement edges, building pads, and other moisture-sensitive improvements. 6.1.5 Following remedial grading, structures can be supported on conventional shallow foundation systems with slab-on-grade floors founded on dense Terrace Deposits or properly compacted fill within the southern portion of the site. Highly expansive clays within the Terrace Deposits were encountered at finish floor elevations near Buildings 1 through 5. Deep footings and thick concrete slabs-on-grade will be required, or these clays should be removed and replaced with low expansive compacted fill. Remedial grading will not be possible where fill/alluvium extends below the water table in the northem portion of the site. Stmctures located in these areas will need to be supported on deep foundations with structural slabs or stone columns. 6.2 Soil and Excavation Characteristics 6.2.1 Laboratory test results indicate that clay layers within the Terrace Deposits possess "very High" expansion potential (Expansion Index [EX} greater than 130) as defmed by Unifonn Building Code Table 18-I-B. The sandy portions of the Terrace Deposits have a low expansion potential. Recommendations presented herein assume either that the highly expansive soils will be left in place or the site will be graded such that soils with an EI of 50 or less will be present at finish grade. Project No. 07353-22-01 - 6 - September 3,2004 6.2.2 We expect that the on-site soils can be excavated with moderate to heavy effort with conventional heavy-duty grading equipmenL 6.2.3 A near-surface soil sample was subjected to pH, resistivity, and water-soluble sulfate content tests. The results are summarized in Appendix B and indicate a corrosive environment with respect to buried metals. The soluble-sulfate test results indicate that concrete structures exposed to soils at the location tested have a "negligible" water-soluble sulfate exposure as defined by UBC Table 19-A-4. Geocon Incorporated does not practice in the field of corrosion engineering. Therefore, if improvements that could be susceprible to corrosion are planned, it is recommended that further evaluation by a corrosion engineer be performed. 6.3 6.3.1 Seismic Design Criteria For seismic design, the southem portion of the site is characterized as soil type Sc- Because the northern portion has a potential for liquefaction, Sp is appropriate. The following table summarizes site design criteria. The values listed on Table 6.3 are for the offshore segment of the Newport-lnglewood Fault, which is identified as a Type B fault and is more dominant than the nearest Type A fault due to its proximity to the site. The offshore segment of the Newport-lnglewood Fault is located approximately 4.3 miles west of the site. TABLE 6.3 SEISMIC DESIGN PARAMETERS Parameter Southem Northern UBC Reference Seismic Zone Factor 0.40 0.40 Table 16-1 Soil Profile Sc SF Table 16-J Seismic Coefficient, Ca 0.40 0.44 Table 16-Q Seismic Coefficient, Cv 0.63 1.08 Table 16-R Near-Source Factor, Na 1.00 1.00 Table 16-S Near-Source Factor, 1.10 1.10 Table 16-T Seismic Source B B Table 16-U 6.4 Mitigation of Liquefaction 6.4.1. Mitigation of liquefaction within the northem portion of the site is expected to consist of either deep foundation systems for the buildings or soil improvement by installation of stone columns. Project No. 07353-22-01 -7-September 3, 2004 6.4.2 If deep foundations are used, the upper 3 feet of existing fill and alluvium should be removed and recompacted to provide uniform support for proposed parking areas and flatwork. These improvements could experience settlement in a liquefaction event, but it is generally not cost effecfive to mitigate liquefaction for such improvements. 6.4.3 Stone columns under construction consist of inserting a vibratory probe into the dense Terrace Deposits and releasing gravel into the hole created by the probe. This is continued to the surface creating a column of stone that densifies the loose sands. Following stone colunm construction, a minimum Cone Penetration Tip resistance of 120 tons per square foot (tsf) in clean sand and 100 tsf in silty sands should be obtained. We expect that the stone columns will be approximately 30 inches in diameter and spaced approximately 8 feet, center to center. 6.4.4 Following stone column constmction, tiie upper 3 feet of existing fill and alluvium will be highly disturbed because of the stone column operation and should be removed and recompacted in accordance with the Grading section of this report. 6.5 Grading 6.5.1 All grading should be performed in accordance with the Grading Ordinance of the City of Carlsbad and the Recommended Grading Specifications in Appendix C. Where the recommendations of this section conflict with those of Appendix C, the recommendations of this section take precedence. 6.5.2 All earthwork should be observed and all fills tested for proper compaction by Geocon Incorporated. 6.5.3 Prior to commencing grading, a preconstruction conference should be held at the site with the owner or developer, grading contractor, civil engineer, and geotechnical engineer in attendance. Special soil handling and/or the grading plans can be discussed at that time. 6.5.4 Site preparation should begin with the removal of all deleterious material, refuse, construction debris, and vegetation. The depth of removal should be such that material exposed in cut areas and soil to be used as fill is relatively free of organic matter. Material generated during stripping and/or site demolition should be exported from the site. 6.5.5 Undocumented fill/alluvium in the southem portion of the site should be removed to firm Terrace Deposits and replaced with properly compacted fill. Localized areas of Project No. 07353-22-01 - 8 - September 3, 2004 undocumented fill, such as the location of former building footings in the southem portion of the site, are expected to be approximately 2 feet in thickness. 6.5.6 If deep foundations are used within the northem portion of the site, the upper 3 feet of existing fill and alluvium should be removed and recompacted prior to installation of the foundations to provide uniform support for parking and flatwork areas. If stone columns are planned, the upper 3 feet of fill and alluvium will be highly disturbed by the stone column operation and should be removed and recompacted. 6.5.7 After unsuitable soil has been removed as described above, the site may be brought to final subgrade elevations with stmctural fill compacted in layers. All areas planned to receive fill should be scarified to a depth of approximately 8 inches, moisture conditioned to slightiy above optimum moisture content, and compacted to at least 90 percent relative compaction. Excavated soils generated during grading, except for the highly expansive clays, should be placed and compacted in layers to the design finish grade elevations. All fill and backfill soil should be placed in loose, horizontal layers approximately 8 inches thick, moisture conditioned to 1 to 3 percent above optimum, and compacted to at least 90 percent relative compaction as determined by ASTM Test Method D 1557-02. Fill areas with test results indicating a soil moisture content below optimum may require addifional moisture conditioning prior to placing additional fill. 6.5.8 Highly expansive clays were encountered neariy finish floor elevation near Buildings 1 through 5. Deep foofings and thick slabs-on-grade are recommended if tiiese clays are left in place. Altematively, the highly expansive clays can be removed to a depth of 5 five below finish grade and replaced with low expansive compacted fill. 6.5.9 The upper 24 inches of soil in streets and parking areas should also consist of low expansive materials. 6.5.10 To reduce the potential for differential settiement, it is recommended that the cut portion of cut/fill transition building pads be undercut to an elevation that is at least 3 feet below the rough grade elevation. 6.5.11 Oversize materials (hard lumps or rock greater than 12 inches in dimension), if encountered, should be placed in accordance with the recommendations for oversize rock placement included in the Recommended Grading Specifications in Appendix C. Project No, 07353-22-01 - 9 - September 3, 2004 6.6 Excavation Slopes, Shoring, and Tiebacks 6.6.1 Deep excavations and cuts can often result in settlement of the surrounding ground surface. This settlement may be sufficient to cause damage or distress to buildings, retaining walls, utilities, services, or other structures located near the excavation. 6.6.2 The Terrace Deposits can be considered Type A soils, in accordance with OSHA guidelines. The undocumented fill and alluvium can be considered Type B soils. Temporary slopes in the Terrace Deposits may be excavated no steeper than VA:1 (horizontahvertical) to a height of 20 feet without shoring. Slopes in existing fill and alluvium should be no steeper than 1:1. Loose cobble should be cleaned fi-om the face of slopes. The top of the excavation should be a minimum of 15 feet from the edge of existing improvements. Excavations steeper than those recommended or closer than 15 feet from an existing improvement may require shoring in accordance with applicable OSHA codes and regulations. 6.6.3 The design of temporary shoring is govemed by soil and groundwater conditions, and by the depth and width of the excavated area. Continuous support of the excavation face should be provided by a system of soldier piles and wood lagging. Excavations exceeding 15 feet may require tieback anchors to provide additional wall restraint. 6.6.4 Temporary cantilevered shoring should be designed for an active soil pressure equivalent to the pressure exerted by a fluid density of 25 pounds per cubic foot (pcf). Additionally, lateral earth pressure due to the surcharging effects of adjacent stmctures and/or traffic loads should be considered, where appropriate, during design of the shoring system. 6.6.5 Passive soil pressure resistance for embedded portions of soldier piles can be based upon an equivalent passive soil fluid weight of 350 pcf The passive resistance can be assumed to act over a width of three pile diameters. Typically, soldier piles should be embedded a minimum of 0.5 times the maximum height of die excavation (this deptii is to include footing excavations). The project stmctural engineer should determine tiie actual embedment depth. 6.6.6 It is essential that the soldier pile and lagging system allow very limited amounts of lateral displacement. Saith pressures acting on a lagging wall can result in the movement of the shoring toward the excavation and result in ground subsidence outside of the excavation. Therefore, we recommend that horizontal movements of the shoring wall be accurately monitored and recorded during excavation and anchor construction. Survey points should be established at both the top and at least one intermediate point between the top of the pile Project No. 07353-22-01 - 10 - September 3,2004 and the base of the excavation on 20 percent of the soldier piles. These points should be monitored on a regular basis during excavation work. The shoring system should be designed to limit horizontal soldier pile movement to less than 1 inch. 6.6.7 Lagging should keep pace with excavation and anchor construction. We recommend that the excavation not be advanced deeper than 3 feet below the bottom of lagging at any time. These unlagged gaps of up to 3 feet should only be allowed to stand for short periods of time in order to decrease the probability of soil sloughing and caving. Backfilling should be conducted when necessary between the back of lagging and excavation sidewalls to reduce sloughing in this zone. Furthermore, the excavation should not be advanced more than 4 feet below a row of tiebacks prior to those tiebacks being proof tested and locked off 6.6.8 If tieback anchors are employed, Geocon should be contacted for additional recommendations. 6.7 Permanent Slopes 6.7.1 Permanent cut and fill slopes will likely be part of site development. Fill and cut slopes with inclinations of 2:1 (horizontal: vertical) should have adequate factors of safety against both deep-seated and surficial instability. 6.7.2 The outer 15 feet of fill slopes, measured horizontal to the slope face, should be composed of properly compacted granular soil fill to reduce the potential for surficial sloughing. Consideration should be given to the use of jute mesh or other surface treatment to minimize transport by runoff until adequate vegetation can be established. 6.7.3 AU fill slopes should be overbuilt at least 3 feet horizontally and cut back to the design finish grade. As an altemative, fill slopes may be compacted by back-rolling at vertical intervals not to exceed 4 feet and then track-walked with a Caterpillar D8 tractor (or equivalent) upon completion such that the fill soils are uniformly compacted to at least 90 percent relative compaction to the face of the finished slope. 6.7.4 Drainage devices should be provided to prevent the discharge of water over the tops of all slopes. All slopes should be planted, drained and properly maintained to reduce erosion. Project No. 07353-22-01 - U - September 3, 2004 6.8 Foundation Recommendations 6.8.1 The following foundation recommendations are based on the assumption that the prevailing soil within 5 feet of finish grade beneath building pads will consist of compacted fill or terrace deposits with an Expansion Index (EI) less than 50. 6.8.2 Continuous strip footings should be al least 12 inches wide and should extend at least 18 inches below lowest adjacent pad grade. Steel reinforcement for continuous footings should consist of four No. 4 steel-reinforcing bars placed horizontally in tiie footings, two near the top and two near the bottom. The project structural engineer should design steel reinforcement for spread footings. Figure 6 presents a typical footing dimension detail depicting the depth to lowest adjacent grade. 6.8.3 Isolated spread footings that are a minimum of 2 feet square and founded 18 inches below lowest adjacent pad grade in properiy compacted fill or formational soils may be designed for the allowable soil bearing pressures recommended below. 6.8.4 If highly expansive clays are left in place, the following foundation recommendafions should be used. Continuous strip footings should be at least 12 inches wide and should extend at least 36 inches below lowest adjacent pad grade. Steel reinforcement for continuous footings should consist of four No. 5 steel-reinforcing bars placed horizontally in the footings; two near the top and two near the bottom. Isolated spread footings should be a minimum of 2 feet square and founded 24 inches below lowest adjacent pad grade in the highly expansive Terrace Deposits. 6.8.5 Foundations may be designed for an allowable soil bearing pressure of 2,500 pounds per square foot (psf) (dead plus live load) for footings founded in properiy compacted fill or firm Terrace Deposits. These soil-bearing pressures may be increased by 200 psf and 400 psf for each addifional foot of foundation width and depth respectively, up to a maximum allowable soil pressure of 3,500 psf 6.8.6 The allowable bearing pressures recommended above may be increased by up to one-third for transient loads such as those due to wind or seismic forces. 6.8.7 The minimum foundation dimensions and steel reinforcement recommendations presented above are based on soil characteristics only and are not intended to replace reinforcement required for stmctural considerations. Project No. 07353-22-01 - 12 - September 3. 2004 6.8.8 Foundation excavations should be observed by a representative of Geocon Incorporated prior to the placement of reinforcing steel or concrete to detemiine whether the exposed soil conditions are consistent with those anticipated. If unanticipated soil condifions are encountered, foundation modificafions may be required. 6.8.9 No special subgrade presaturation is deemed necessary prior to placing concrete; however, the exposed foundation and slab subgrade soils should be sprinkled, as necessary, to maintain a moist condition as would be expected in any such concrete placement. 6.8.10 Where buildings or other improvements are planned near the top of a slope steeper than 3:1 (horizontahvertical), special foundations and/or design considerations are recommended due to the tendency for lateral soil movement to occur. Building footings should be deepened such that the bottom outside edge of the footing is at least 7 feet horizontally inside the face of the slope. Although other improvements that are relatively rigid or brittie (such as concrete fiatwork or masonry walls) may experience some distress if located near the top of a slope, it is generally not economical to mitigate this potenfial. It may be possible, however, to incorporate design measures that would permit some lateral soii movement without causing extensive distress. Geocon Incorporated should be consulted for specific recommendations. 6.9 Deep Foundations 6.9.1 Undocumented fill/alluvium was encountered along the northem edge of the property. In areas were these soil types extend below the water table, there is the potential for liquefaction. Deep foundations can be used for support of buildings. A structural slab also supported by the deep foundation system is recommended. Due to noise limitations, we expect the driven pile cannot be used. Therefore, recommendations for drilled piers and auger-cast piles are provided below. 6.9.2 Drilled piers will develop support by both friction and end bearing in the Terrace Deposits at depth. Drilled piers should be at least 24-inches in diameter and should extend at least 5 feet into competent Terrace Deposits. Auger-cast piles are generally 14-inches or 16-inches in diameter and should also extend at least 5 feet into competent Terrace Deposits. 6.9.3 An allowable end bearing capacity of 20,000 pounds per square foot (psf) can be used for design of drilled piers and auger-cast piles. An allowable skin friction of 600 psf may be used for the portion of the drilled pier within die Terrace Deposits. No skin friction is permitted within the undocumented fill or alluvium/slope wash soil. For preliminary design purposes, the top of the competent Terrace Deposits can be assumed to be at Elevation -10 Project No. 07353-22-01 - 13 - September 3, 2004 feet MSL although it is actually variable across the site. The maximum tip elevation would therefore be approximately -5 feet MSL. Allowable uplift capacities can be taken as the allowable friction resistance over the entire drilled pier/auger-cast pile length, including the fill/alluvium. The upfift capacity may also be limited by structural considerations and should be checked by the structural engineer. Downdrag loads due to liquefaction have been incorporated into the design. 6.9.4 If pile spacing is at least four times the maximum dimension of the pile, no reduction in axial capacity for group effects is considered necessary. 6.9.5 The lateral loads at the ground surface that produce a deflection of V2 inch at the pile cap under both liquefied and non-liquefied conditions are presented on Table 6.8. These capacities can be increased proportionately with deflection to a maximum deflection of 1 inch. If greater capacities than those shown on Table 6.8 are needed, Geocon should be contacted to develop specific lateral capacity-deflection curves on a case-by-case basis. TABLE 6.9 LATERAL LOAD/DEFLECTION FOR DRILLED PIERS/ACP Pile Type Lateral Load in kips Pile Type Fixed Head Free Head 14-inch ACP (nonliquefied) 16.5 kips 7.0 kips 16-inch ACP (nonliquefied) 21.0 kips 9.3 kips 24-inch drilled pier (nonliquefied) 43.8 kips 20.7 kips U-inch ACP (liquefied) 14.8 kips 6.5 kips 16-inch ACP (liquefied) 17.4 kips 8.9 kips 24-inch drilled pier (liquefied) 29.8 kips 18.8 kips 6.9.6 Pile settiement is expected to be on the order of Vi-inch for drilled piers and auger cast piles. Settiements should be essentially complete shortly after completion of the structure. 6.9.7 Drilled piers will have to be constructed using a water or slurry displacement method of constmction. Because a portion of the drilled pier capacity will be developed by end bearing, the bottom of the borehole should be cleaned of all loose cuttings prior to the placement of steel and concrete. Concrete should be placed within the pier excavation as soon as possible after the auger/cleanout plate is withdravra to reduce the potential for discontinuities or caving. Concrete should be placed with a tremie and the bottom of the tremie should be maintained below the level of the concrete at all times. Because concrete Project No. 07353-22-01 - 14-September 3. 2004 will be placed below groundwater, PVC pipes should be attached to the reinforcing cage to provide a method of performing non-destructive testing ofthe drilled piers in the event that questions arise regarding the structural integrity of the drilled piers. Initial set of the concrete should occur prior to drilling adjacent piles within 5 pile diameters. 6.9.8 Auger-cast piles may be may be used in Heu of drilled piers. The quality of auger cast piles is highly dependent on the contractor's experience and constmction observation. The contractor should supply equipment to accurately measure concrete grout volumes and a mud balance to evaluate specific gravity. The volume of grout pumped should exceed the theoretical volume of the pile by 15 to 20 percent. The specific gravity of the concrete grout should be 1.8 to 1.9 which corresponds to a water/cement ratio of approximately 0.45 to 0.5. The withdrawal rate of the auger should be such that the bottom of the auger is always maintained at least 3 feet below the top of the upward rising concrete grout column. Initial set of the concrete grout should occur prior to drilling adjacent piles within 5 pile diameters. 6.9.9 Based on laboratory testing, the on-site soils are conosive with respect to steel. The groundwater is expected to be saltwater. The stmctural engineer should take this data into account when selecting cement quantities and types for piles. Adequate concrete cover over reinforcing steel should be provided in accordance with good constmction practices and design standards. 6.10 Concrete Slabs 6.10.1 If structures in the northern portion of the site are supported on piles, structural slabs should be used. Concrete slabs-on-grade for the southern portion of the site should be at least 5 inches thick. Minimum slab reinforcement should consist of No. 3 steel reinforcing bars placed 18 inches on center in both horizontal directions and positioned within the upper one-third of the slab. The concrete slabs-on-grade should be imderlain by at least 4 inches of clean sand and, where moisture-sensitive floor coverings are planned, a visqueen moisture barrier placed at the midpoint of the sand cushion should be provided. The concrete slabs-on-grade should also be provided with isolation or expansion joints to permit vertical movement between the slabs, footings and walls. 6.10.2 Crack-control joints should be spaced at intervals not greater than 12 feet and should be constructed using sawcuts or other methods as soon as practically possible following concrete placement. Crack-control joints should extend a minimum depth of one-fourth the slab thickness. Project No. 07353-22-01 - 15 - September 3, 2004 6.10.3 Exterior slabs not subject to vehicular loads should be at least 4 inches thick and reinforced with 6x6-W2.9AV2.9 (6x6-6/6) welded wire mesh. The mesh should be placed within the upper one-third of the slab. Proper mesh positioning is critical to future performance of the slab. It has been our experience that the mesh must be physically pulled up into the slab after concrete placement. The contractor should take extra measures to provide proper mesh placement. Prior to construction of slabs, the subgrade should be moisture conditioned to at least optimum moisture content and compacted to at least 90 percent relative compaction. The subgrade soils should not be allowed to dry prior to placing concrete. 6.10.4 The recommendations of this report are intended to reduce the potential for slabs to crack due to difl"erential settlement of fill soils. However, even with the incorporation of the recommendations presented herein, foundations, stucco walls and slabs-on-grade placed on such soil conditions may exhibit some cracking due to soil movement and/or shrinkage. The occurrence of concrete shrinkage cracks is independent of the supporting soil characteristics. Their occurrence may be reduced and/or controlled by limiting the slump of the concrete, proper concrete placement and curing, and the placement of crack-control joints at periodic intervals, particularly where re-entrant slab comers occur. 6.11 Retaining Walls and Lateral Loads 6.11.1 Retaining walls that are allowed to rotate more than 0.00IH (where H equals the height of the retaining wall portion of the wall in feet) at the top of the wall and having a level backfill surface should be designed for an active soil pressure equivalent to the pressure exerted by a fluid density of 35 pounds per cubic foot (pcO- Where the backfill will be inclined at no steeper than 2:1, an active soil pressure of 50 pcf is recommended. These soil pressure recommendations are provided with the assumption that the backfill soil within an area bounded by the wall and a 1:1 plane extending upward from the base of the wall possess an Expansion Index of less than 50. 6.11.2 Where walls are restrained from movement at the top, an additional uniform pressure of 7H psf should be added to the above active soil pressure. 6.11.3 All retaining walls should be provided with a drainage system adequate to prevent the buildup of hydrostatic forces and should be waterproofed as required by the project architect. The use of drainage openings through the base of the wall (weep holes) is not recommended where the seepage could be a nuisance or otherwise adversely impact the property adjacent to the base of the wall. A typical retaining wall drainage detail is presented on Figure 7. The above recommendations assume a properly compacted backfill Project No. 07353-22-01 - 16 - Septembers, 2004 materia] with no hydrostatic forces or imposed surcharge load. If conditions different than those described are anticipated, or if specific drainage details are desired, Geocon Incorporated should be contacted for additional recommendations. 6.11.4 Wall foundations should extend 12 inches and 24 inches below adjacent grade for walls founded in low expansive granular fill and highly expansive Terrace Deposits, respectively. An allowable bearing capacity of 2,500 psf can be used for retaining walls. The proximity of the foundation to the top of a slope steeper than 3:1 could impact the allowable soil bearing pressure. Therefore, Geocon Incorporated should be consulted where such a condition is anticipated. 6.11.5 For resistance to lateral loads, an allowable passive earth pressure equivalent to a fluid density of 350 pcf is recommended for footings or shear keys poured neat against properly compacted granular fill soils or undisturbed natural soils. The allowable passive pressure assumes a horizontal surface extending away fi-om the base of the wall at least 5 feet or three times the height of the surface generating the passive pressure, whichever is greater. The upper 12 inches of material not protected by floor slabs or pavement should not be included in the design for lateral resistance. 6.11.6 An allowable friction coefficient of 0.35 may be used for resistance to sliding between soil and concrete. This friction coefficient may be combined with the allowable passive earth pressure when determining resistance to lateral loads. 6.11.7 The recommendations presented above are generally applicable to the design of rigid concrete or masonry retaining walls having a maximum height of 12 feet. In the event that walls higher than 12 feet or other types of walls (such as crib-type walls) are planned, Geocon Incorporated should be consulted for additional recommendations. 6.12 Preliminary Pavement Section 6.12.1 The following pavement sections are preliminarj' and assume that granular fill will be present at subgrade elevation. Actual pavement sections should be determined once subgrade elevations are attained at the end of grading and additional R-value testing is performed on subgrade soil samples. Utilizing the laboratory determined R-value and procedures outlined in the Caltrans Highway Design Manual. Section 600, pavement sections were evaluated and are presented on Table 6.12. Project No. 07353-22-01 - 17 - September 3,2004 TABLE 6.12 PRELIMINARY PAVEMENT SECTIONS Location Assumed Traffic Index Asphalt Concrete (inches) Class 2 Aggregate Base (inches) Auto Parking and Driveways 5.0 3.0 4.0 Truck Traffic/Fire Lane 7.0 4.0 4.5 6.12.2 Prior to placing aggregate base materials, pavement area subgrade soil should be scarified to a depth of 12 inches compacted to a minimum of 95 percent relative compaction. 6.12.3 Class 2 base should conform to Section 26-1.02A of the Standard Specifications for the State of Califomia Department of Transportation (Caltrans) and should be compacted to a minimum of 95 percent of the maximum dry density at near-optimum moisturel content. Asphalt concrete should conform to Section 203-6 of the Standard Specifications for Public Works Construction (Greenbook). 6.12.4 Where trash bin enclosures are planned within asphalt paved areas, we recommend that the pavement section consist of 6 inches of Portland Cement concrete (minimum Modulus of Rupture of 600 psi) reinforced with No. 3 bars spaced at 18 inches in each horizontal direction. The concrete should extend into the roadway sufficientiy so that the entire truck is on the concrete when loading and unloading. 6.12.5 The performance of asphalt concrete pavements and Portland Cement concrete pavement is highly dependent upon providing positive surface drainage away from the edge of the pavement. Ponding of water on or adjacent to pavement will likely result in premature pavement distress and subgrade failure. If planter islands are proposed, the perimeter curb should extend at least 12 inches below the aggregate base of the adjacent pavement. In addition, surface drainage within the planter should be such that ponding will not occur. 6.13 Drainage 6.13.1 Establishing proper drainage is necessary to reduce the potential for differential soil movement, erosion, and subsurface seepage. Positive measures should be taken to properly finish grade the building pads after stmctures and other improvements are in place, so that drainage water from the building pads and adjacent properties is directed to streets and away from foundations and tops of slopes. Experience has shown that even with these provisions, a shallow groundwater or subsurface condition can and may develop in areas where no such condition existed prior to site development. This is particularly tme where a Project No. 07353-22-01 -18-September 3, 2004 substantial increase in surface water infiltration results from an increase in landscape irrigation. 6.14 Grading and Foundation Plan Review 6.14.1 The geotechnical engineer and engineering geologist should review the grading and foundation plans prior to finalization to verify their compliance with the recommendations of tills report and determine the necessity for additional comments, recommendations and/or analysis. Project No. 07353-22-01 - 19 - September 3, 2004 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 constmction will differ from that anticipated herein, Geocon Incorporated should be notified so that supplemental recommendations can be given. The evaluation or identification of the potential presence of hazardous or conosive materials was not part of the scope of services provided by Geocon Incorporated. This report is issued with the understanding that it is the responsibility of the owner or his representative to ensure that the infonnation and recommendations contained herein are brought to the attention of the architect and engineer for the project and incorporated into the plans, and that the necessary steps are taken to see that the contractor and subcontractors carry out such recommendations in the field. The findings of this report are valid as of the present date. However, changes in the conditions of a property can occur with the passage of time, whether due to natural processes or the works of man on this or adjacent properties. In addition, changes in applicable or appropriate standards may occur, whether a result of legislation or the broadening of knowledge. Accordingly, the findings of this report may be invalidated wholly or partially by changes outside our control. Therefore, this report is subject to review and should not be relied upon after a period of three years. Project No. 07353-22-01 September 3, 2004 1 VIET* IttV VIllJttE K Z CAS OE ALICIA 3 PAS K ERISAS 4 CAS OE COUWO 5 MOn UaiA HICICHQA S PAS •£ LS WERICANOS ; CA£ oe oiLOifs e »AS DE ELENITA 9 PAS DE FItAIKlSCC 10 PAS DE LS CALIFORKIAlOS SEcXy H3 1 VIA OtEQD 2 mjuw 3 VIA HDBERTO ' VIUBOCAS S VIA $A£1*1AS fi VIA VERA 7 VIA CADDEL B VlAlffimSE 9 VIA HERD£ 10 Vll. TONAU. 1) CL tW:i£N» 1£ VJACAJITA SOURCE; 2004 THOMAS BROTHERS MAP SAN DIEGO COUNTY, CA1.IF0RNIA , REPRODUCED WITH PERMJSSlOW GRAWTB3 BY THOMAS BORTHERS MW>S, THISMAPISCOPYRJOHTSYTHOIilASBROS. KWPS. fflS UNLAWFUL TO COPY OR REPRODUCE ALL OR ANY PART THEREOF, WHET>1Hl FOR PERSONAL USE OR RESALE, WITHOUT PERMISSION, N NO SCALE GEOCON INCORPORATED a GEOTECHNICAL CONSULTANTS 6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121 - 2974 PHONE BBB 55&-6900 - FAX 858 558-6159 KC/RA DSK/EOOOO C/OeoMiMi and SfKin^/Drnfiine 2/fcjh»nn«inplaiwniiipbii«/G»mcySiW Pbn VICINITY MAP OCEAN STREET CONDOMINIUMS CARLSBAD, CALIFORNIA DATE 09-03-2004 PROJECT NO. 07353 - 22 - 01 FIG. 1 GEOLOGIC MAP OCEAN STREET CONDOMINIUMS CARLSBAD, CALIFORNIA SCALE: 1" = 60' GEOCON LEGEND Qudf/Sl UNDOCUMENTED FILL, ANO ALLUVIUM (Undifferentiated) Qt TERRACE DEPOSITS {OtMoi Where Buried) ® APPROX LOCATION OF GEOTECHNICAL BORING ?^ APPROX. LOCATION OF GEOLOGIC COrsTTACT (Querrieil Where Uncertain) E' 1 APPROX. LOCATION OF GEOLOGIC CROSS - SECTION GEOCON INCORPORATED GEOTECHNJCAL COMSUITANTS 6960 FUNDERS DRIVE • SAN DIEGO, CAUFORKA92121 - 2974 PHONE 858 558-6900 - FAX 858 558-6159 PROJEa NO. 07353-22-01 FIGURE 2 DATE 09-03-2005 C/Doumwin and Sartinot/Drofiinc 4/07353 CXEAN STRST ODO/DWG. 90 -1 60 - LU LU zf 30- 0 — -30—1 EXISTING GF?ADE PROPOSED BUILDING- J J. J EXISTING BUILDING .7. T 30 60 120 150 -PROPOSED BUILDING- EXISTING BUILDING B-3 B-2 .9. 90 120 150 180 DISTANCE, FEET GEOLOGIC CROSS - SECTION T" 210 240 SCALE: 1" = 30' (HORIZ. = VERT.) GEOCON LEGEND Qudf/Sl UNDOCUMENTED FILL, AND ALLUVIUM (Undifferentiated) Qf TERRACE DEPOSITS APPROX. LOCATION OF GEOLOGIC CONTACT (Querried Where Uncertain) S X APPROX. LOCATION OF GROUNDWATER TABLE {Querried Where Uncertain) OCEAN STREET CONDOMINIUMS CARLSBAD, CALIFORNIA c I- 90 Qt - 60 LU LU IJ. 30 zf o i LU _I Ul -0 '—-30 265 GEOCON INCORPORATED GEOTECHNCAL CONSULTANTS 6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA92121 - 2974 PHONE 858 558-6900 - FAX 858 558-6159 PROJEa NO. 07353 - 22 - 01 FIGURE 3 DATE 09-03-2004 C/Doeumwm ond Sattinoi/Droliino il/07353 OCEAN STRET COhDCMWG. OCEAN STREET CONDOMINIUMS CARLSBAD, CALIFORNIA D 90 -1 60 - z" 30 — 0- -30-J GEOLOGIC CROSS - SECTION SCALE: 1" = 30' (HORIZ. = VERT.) GEOCON LEGEND QUdf/sl UNDOCUMENTED FILL. WJD ALLUVIUM (Undifferentiated) Qf TERRACE DEPOSrrS APPROX. LOCATION OF GEOLOGIC CONTACT (Querried Where Uncertain) .7 X APPROX. LOCATION OF GROUNDWATER TABLE (Querried Where Uncertain) GEOCON INCORPORATED I- 90 - 60 I-LU LU U. 30 zf g > LU -0 1--30 420 GEOTECHNICAL CONSULTANTS 6960 FLANDERS DRIVE - SAN DIEGO, CAUFORNIA 92121 - 2974 PHONE 858 558-6900 - FAX 858 558-6159 PROJEa NO. 07353 - 22 - 01 FIGURE 4 DATE 09-03-2004 C:/Docii>n«ir> and S^ninsuTMong 4/07353 OCEAN STRST CONDO/DWa 90—1 60- z" 30- 0- -30-" OCEAN STREET CONDOMINIUMS CARLSBAD, CALIFORNIA E' I— 90 - 60 tu tu 30 2 g 5 -0 «—-30 30 60 90 120 150 180 210 DISTANCE, FEET 240 270 300 "T 330 360 390 40O GEOLOGIC CROSS - SECTION SCALE: 1" = 30' (HORIZ. = VERT.) GEOCON LEGEND Qudf/sl UNDOCUMENTED FILL, AND ALLUVIUM (Undifferentiated) Qf TERRACE DEPOSn^ ^PROX LOCATION OF GEOLOGIC CONTACT (Querried Where Uncertain) .7 % APPROX. LOCATION OF GROUNDWATER TABLE (Querried Where Uncertain) GEOCON IN CORPORATED GEOTECHNICAL CONSULTANTS 6960 FLANDBEiS DEMVE - SAN DEGO, CAUFORNIA92121 - 2974 PHONE 858 558-6900 - FAX 858 558-6159 PROJEa NO. 07353 - 22 - 01 FIGURE 5 DATE 09-03-2004 C/DMHwm and 5Mtii>0t/Ora(«na 4/07353 OCEAN STKST OOO/DWG. WALL FOOTING CONCRETE SLAB SAND VISQUEEN (-0- >> O LU ^ •,.4 '-^^ PAD GRADE J 8S "••1 FOOTING* WIDTH COLUMN FOOTING CONCRETE SLAB SAND FOOTING WIDTH- NO SCALE ....SEE REPORT FOR FOUNDATION WITDH AND DEPTH RECOMMENDATION WALL / COLUMN FOOTING DIMENSION DETAIL GEOCON ^ INCORPORATED GEOTECHNICAL CONSULTANTS 6960 FLANDERS DRIVE - SAN DIEGO, CAUFORNIA 92121 - 2974 PHONE 858 558-6900 - FAX 858 558-6159 OCEAN STREET CONDOMINIUMS CARLSBAD, CALIFORNIA KC/RA DSK/EOOOO DATE 09-03-2004 PROJECT NO. 07353 - 22 - 01 FIG. 6 COLFOOr2DWGffiA GROUND SURFACE RETAINING WALL 3/4" CRUSHED GRAVEL MIRAFI WON RLTER FABRIC OR EQUIVALENT 4' DIA. PERFORATED SCHEDULE 40 PVC PIPE NOTES: 1 PREFABRICATED DRAINAGE PANELS, SUCH AS MIRADRAIN 7000 XL OR EQUIVALENT, MAYBE USED IN LIEU OF PLACING GRAVEL TO HEIGHT OF 2/3 THE TOTAL WALL HEIGHT 2 DRAIN SHOULD BE UNIFORMLY SLOPED AND MUST LEAD TO A POSITIVE GRAVITY OUTLET 3 TEMPORARY EXCAVATION SLOPES SHOULD BE CONSTRUCTED AND/OR SHORED IN ACCORDANCE WITH CAL-OSHA REGULATIONS NO SCALE RETAINING WALL DRAINAGE DETAIL GEOCON INCORPORATED GEOTECHNICAL CONSULTANTS 6960 FLANDERS DRIVE - SAN DIEGO, CAUFORNIA 92121 - 2974 PHONE 858 558-6900 - FAX 858 558-6159 KC/RA DSK/EOOOO OCEAN STREET CONDOMINIUMS CARLSBAD, CAUFORNIA DATE 09-03-2004 PROJECT NO. 07353 - 22 - 01 FIG. 7 lirrWAti4.DWC/RA APPENDIX APPENDIX A FIELD INVESTIGATION The field investigation was performed on July 16 and 26 and August 27, 2004, and consisted of a site reconnaissance and drilling ten exploratory small-diameter borings at the approximate locations shown on Figure 2. The small-diameter borings were drilled to depths varying from 16 to SOVi. Borings Bl through B3 were drilled with a CME 55 drill rig equipped with hollow-stem auger. Borings B4 through BIO were drilled with a mud rotaiy drill rig. Relatively undisturbed samples were obtained by driving a Califomia Modified Sampler 12 inches with blows from a 140-pound hammer falling 30 inches. This split-tube sampler was equipped with 1-inch-high by 2VB-inch-diameter brass sampler rings to facilitate sample removal and testing. Disturbed bulk samples were obtained from the boring's cuttings. The soil conditions encountered in the borings were visually examined, classified and logged in general accordance with the American Society for Testing and Materials (ASTM) Practice for Description and Identification of Soils (Visual-Manual Procedure D 2488). The logs of the exploratory borings are presented on Figures A-1 through A-10. The logs depict the various soil types encountered and indicate the depths at which samples were obtained. Project No, 07353-22-01 September 3, 2004 PROJECT NO. 07353-22-01 SAMPLE NO, SOIL CLASS (USCS) BORING B 1 ELEV. (MSL) EQUIPMENT -38 DATE COMPLETED CME 55 07-16-2004 ov-2 Si ^2 UJ 3^ to Oz S O u - 0 - 2 - t- 4 - - 6 - - 8 - - 10 - - 12 - - 14 - - 16 - 18 - Bl-1 Bl-2 Bl-3 BM Bl-5 Bl-6 20 SM CH SM MATERIAL DESCRIPTION 4" ASPHALT CONCRETE TERRACE DEPOSITS Medium dense, moist, brown, Silty, fine to medium SAND Hard, moist, tan-brown, CLAY -Becomes very stiff and brown at 13 feet Medium dense, moist, brown, Silty, fine to medium SAND 15 104.8 23 102.1 52 14.5 37 94,1 36 96,0 BORING TERMINATED AT 20 FEET No groundwater Hole filled with cuttings mixed with 1 bag ponland cement Figure A-1, 7353-22-01.GPJ Log of Boring B 1, Page 1 of 1 SAMPLE SYMBOLS D .., SAMPLING UNSUCCESSFUL C ... STANDARD PENETRATION TEST 1.. DRIVE SAMPLE (UNDISTURBED) ^ ... DISTURBED OR BAG SAMPLE E ... CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES, PROJECT NO. 07353-22-01 - 20 ' 2 - - 6 - - 10 - - 12 - - 14 - - 16 ' - 18 - SAMPLE NO B2-I B2-2 B2-3 I B2-4 B2-5 B2-6 B2-7 SOIL CLASS (USCS) SM CH SP BORING B 2 ELEV. (MSL.) EQUIPMENT -35 DATE COMPLETED 07-16-2004 CME 55 MATERIAL DESCRIPTION 4" ASPHALT CONCRETE TERRACE DEPOSITS Medium dense, moist, red-brown, Silty, fme lo medium SAND Very stiff, moist, brown, CLAY Dense, moist, tan, fine to coarse SAND 2 o I-h- z u. I- w g 5S£ 30 50/6" Z ll Q 118.4 108.3 46 46 96.2 102,1 96.8 o z 5 O o 5.7 9.5 26.2 7.8 4,4 BORING TERMINATED AT 20 FEET No groundwater Hole filled with cunings mixed with I bag portland cement Figure A-2, 7353-22-01,GPJ Log of Boring B 2, Page 1 of 1 r- « D „. SAMPLING UNSUCCESSFUL SAMPLE SYMBOLS I] ... STANDARD PENETRATION TEST 1 .,. DRIVE SAMPLE (UNDISTURBED) ^ ... DISTURBED OR BAG SAMPLE B ... CHUNK SAMPLE I ,., WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONOmONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND ATTHE DATE INDICATED, IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES, PROJECT NO. 07353-22-01 DEPTH IN FEET SAMPLE NO. SOIL CLASS (USCS) BORING B 3 ELEV. (MSL.) EQUIPMENT -32 DATE COMPLETED CME 55 07-16-2004 O I- a: o - 0 MATERIAL DESCRIPTION - 2 - - 4 - - 6 - - 8 - - 10 - - 12 - - 14 - - 16 - - 18 - B3-1 B3-2 SM ML B3-3 CH SP B3-5 B3-6 - 20 CL UNDOCUMENTED FILL/ALLUVIUM Medium dense, moist, dark-brown, Silty, fine to medium SAND TERRACE DEPOSITS Firm, moist, brown, Sandy SILT 11 113.8 Firm, moist, brown, CLAY -Gravel at 7 feet 12 37 107.8 Dense, moist, gray-brown, fine to coarse SAND -Gravel lavet at 17 feet Hard- moisi- erav-brown. CLAYSTONE 46 49 110.2 6.8 31.9 BORING TERMINATED AT 20 FEET Hole filled with cuttings mixed wilh 1 bag ponland cement Figure A-3, 7353-22-01.GPJ Log of Boring B 3, Page 1 of 1 SAMPLE SYMBOLS ° • ^'^^-'^^^^^^-^ IJ .„ STANDARD PENETRATION TEST B ,., DRIVE SAMPLE (UNDISTURBED) ^ ... DISTURBED OR BAG SAMPLE E „, CHUNK SAMPLE I ...WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY ATTHE SPECIFIC SORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. PROJECT NO. 07353-22-01 DEPTH IN FEET SAMPLE NO, HOLOGY JNDWATER 1 SOIL CLASS (USCS) BORING B 4 ELEV. (MSL.) -38 DATE COMPLETED 07-26-2004 PENETRATION RESISTANCE (BLOWS/FT.) DENSITY P.C.F,) MOISTURE CONTENT(%) DEPTH IN FEET h- _I GROL SOIL CLASS (USCS) EQUIPMENT MUD ROTARY PENETRATION RESISTANCE (BLOWS/FT.) ?- — CH o MOISTURE CONTENT(%) - n -MATERIAL DESCRIPTION u TERRACE DEPOSIT Very dense, moisl, red-brown, Silty, fine to medium SAND - - 2 -B4-1 ' 50/6" U9.2 n.9 - 4 -•lil-- -B4-2 65 110,9 5,2 - 6 -'•1 •!• 1 -| '\'] "1 - - 8 - .r SM - - 10 -B4-3 1 -Becomes tan -brown at 10 feet 65 - 12 - - 14 - -B4-4 1 63 109.4 15,1 - 16 -1 - 18 - -B4-5 1 78 106,7 16.4 1 • I-1 1 BORING TERMINATED AT 20 FEET No groundwater encountered Hole filled with 15 gallons of bentonite slurry Figure A-4, Log of Boring B 4, Page 1 of 1 7353-22-D1.GPJ SAMPLE SYMBOLS n „, SAMPLING UNSUCCESSFUL G . STANDARD PENETRATION TEST • , DRIVE SAMPLE (UNDISTURBED) SAMPLE SYMBOLS ^ „, DISTURBED OR BAG SAMPLE CHUNK SAMPLE . WATER TABLE OR SEEPAGE WOTE, THE LOG OP SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. PROJECT NO, 07353-22-01 DEPTH IN FEET SAMPLE NO, SOIL CLASS (USCS) BORING B 5 ELEV. (MSL.) EQUIPMENT -15 DATE COMPLETED 07-26-2004 MUD ROTARY ^ UJ -r I- w & Zti- cc - 0 MATERIAL DESCRIPTION - 2 - _ 4 - - 6 - B5-1 I SM B5-2 - 10 - - 12 - - 14 - - 16 - - 11 B5-3 i SC B5-4 I B5-5 ML UNDOCUMENTED FILL/ALLUVIUM Loose, moist, tan and brown, Silty, fme to coarse SAND Loose to medium dense, moist, brown. Clayey, fine to coarse SAND -Becomes saturated at 11 feet -1 foot layer of gravel at 13 feet TERRACE DEPOSITS Hard, saturated, gray-green, Sandy SLIT -No recovery 11 111,5 U0.9 19 74/10" 113,4 50/6" BORING TERMINATED AT 19.5 FEET Groundwater encountered at 11 feet Hole filled with 15 gallons of bentonite slurry Figure A-5, 7353-22-01,GPJ Log of Boring B 5, Page 1 of 1 SAMPLE SYMBOLS ° • • UNSUCCESSFUL C ... STANDARD PENETRATION TEST 1 „, DRIVE SAMPLE (UNDISTURBED) ^ „, DISTURBED OR BAG SAMPLE B „, CHUNK SAMPLE I. ... WATER TA8LE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPUES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES PROJECT NO, 07353-22-01 DEPTH IN FEET SAMPLE NO. SOIL CLASS (USCS) BORING B 6 ELEV. (MSL.) _ EQUIPMENT -16 DATE COMPLETED 07-26-2004 MUD ROTARY I- w g CO -r Z u. °t CC Q UJ 3^ ii Oz S o o - 0 MATERIAL DESCRIPTION - 2 - - 4 - - 6 - B6-1 B6-2 I [• SM - 10 - - 12 - - 14 - J J. ML SM SM B6-3 I B6-4 ML UNDOCUMENTED FILL/ALLUN'IUM Medium dense, moist, brown, Silty, fine to coarse SAND 20 106.0 Stiff, moist, gray-green, Sandy SILT Medium dense, moist, red-brown, Silty, fine to coarse SAND 12 TERRACE DEPOSITS Very dense, pale gray, Silty, fine to coarse SAND 88/9" 106.4 Hard, saturated, tan, Sandy SILT 50/3' 8.0 17.9 BORING TERMINATED AT 15.75 FEET Groimdwater encountered at 11.5 feel Hole filled with 7 gallons of bentonite slurry Figure A-6, 7353-22-01 .GPJ Log of Boring B 6, Page 1 of 1 . ,r,«, ^ • ...SAMPLING UNSUCCESSFUL SAMPLE SYMBOLS C ... STANDARD PENETRATION TEST 1 ... DRIVE SAMPLE (UNDISTURBED) ^ ... DISTURBED OR BAG SAMPLE K .„ CHUNK SAMPLE X •• WATER TABLE OR SEEPAGE NOTE. THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY ATTHE SPECIFIC SORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES- PROJECT NO. 07353-22-01 DEPTH IN FEET SAMPLE NO, HOLOGY JNDWATER 1 SOIL CLASS (USCS) BORING B 7 ELEV. (MSL.) -14 DATE COMPLETED 07-26-2004 PENETRATION RESISTANCE (BLOWS/FT.) ' DENSITY P.C.F.) MOISTURE CONTENT (%) h- _i GROI SOIL CLASS (USCS) EQUIPMENT MUD ROTARY PENETRATION RESISTANCE (BLOWS/FT.) •—• cc Q MOISTURE CONTENT (%) - n -MATERIAL DESCRIPTION . '1 , UNDOCUMENTED FILL/ALLUVIUM Medium dense, moist, orange-brown, Silty, fine to coarse SAND _ ~ 2 -B7-1 1 [;'•: 11 - A - - 6 - B7-2 SM -Becomes gray 25 112.5 16.6 - 8 - - 10 - • -Layer of asphalt concrete at 9 feel -- 8 - - 10 -B7-3 Soft, wet, dark gray, Sandy SILT; organic odor 4 - 12 - 1. ,1 -Becomes saturated at 11,5 feet - 14 - ML - 16 - B7.4 1 5 105.2 14.9 - 18 - - 20 -B7-5 •77 Medium dense, saturated, dark gray. Silly, fine to coarse SAND 15 - 22 -r' 1 SM - 24 - -I fool gravel layer at 23 feet - 24 - SM TERRACE DEPOSITS Figure A-7, Log of Boring B 7, Page 1 of 2 7353-22^)1,GPJ SAMPLE SYMBOLS n .„ SAMPLING UNSUCCESSFUL C „, STANDARD PENETRATION TEST | „. DRIVE SAMPLE (UNDISTURBED) ^ ... DISTURBED OR SAG SAMPLE G ... CHUNK SAMPLE Y. „, WATER TABLE OR SEEPAGE NOTE THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT TME DATE INDICATED IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. PROJECT NO. 07353-22-01 DEPTH IN FEET SAMPLE NO, SOIL CLASS (USCS) BORING B 7 ELEV. (MSL.) -14 EQUIPMENT DATE COMPLETED 07-26-2004 MUD ROTARY UJ — 2 o I-t- z st I- w > Z U. a: o UJ «^ o £ ^8 MATERIAL DESCRIPTION B7-6 I - 26 - - 28 - r 30 -B7-7 i" 50/6" 113.1 15.6 SM 50/5" BORING TERMINATED AT 30.5 FEET Groundwater encountered at 11.5 feet Hole filled with 25 gallons of bentonite slurry Figure A-7, 7353-22-01.GPJ Log of Boring B 7, Page 2 of 2 SAMPLE SYMBOLS ° .-SAMPLINGUNSUCCESSFUL E ... STANDARD PENETRATION TEST B ... DRIVE SAMPLE (UNDISTURBED) ^ ,.. DISTURBED OR BAG SAMPLE G ... CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. PROJECT NO. 07353-22-01 DEPTH IN FEET SAMPLE NO. SOIL CLASS (USCS) BORING B 8 ELEV. £MSL) -10 EQUIPMENT DATE COMPLETED 08-27-2004 MUD ROTARY 2 o t- I- Z Et • w g I— to '^ 2 u. ml" Oz so u h 0 - 2 r 4 - 6 - MATERIAL DESCRIPTION B8-1 B8-2 [ - 10 - - 12 - - 14 - - 16 - - 18 - 20 - 22 - 24 - B8-3 1^ 3-4 B8-5 I -6 W. "I SC SM SM SP UNDOCUMENTED FILL/ALLUVIUM Very dense, moist, brown, Clayey, fine to coarse SAND Loose, moist, brown, Silty, fine to coarse SAND, some gravel Loose, saturated, black, Silty, fine to coarse SAND and GRAVEL Loose, saturated, gray, fine to medium SAND -Becomes medium dense, some concrete in sampler -Gravel layer al 24 feet 53 25 Figure A-8, ?353-22-01,GPJ Log of Boring B 8, Page 1 of 2 SAMPLE SYMBOLS ° ' -^^^^^^SFUL |] .,. STANDARD PENETRATION TEST B ... DRIVE SAMPLE (UNDISTURBED) ^ „, DISTURBED OR BAG SAMPLE C „ CHUNK SAMPLE % „. WATER TABLE OR SEEPAGE NOTE. THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDiTIONS AT OTHER LOCATIONS AMO TIMES. PROJECT NO. 07353-22-01 DEPTH IN FEET SAMPLE NO, SOIL CLASS (USCS) BORING B 8 ELEV. (MSL.) -10 DATE COMPLETED 08-27-2004 EQUIPMENT MUD ROTARY o O I- l_ 2 IL I- w g to O 9 ^ 5 O o MATERIAL DESCRIPTION ^6 - 26 - 28 - 30 - - 32 - 34 - - 36 - - 38 - - 40 - B8-7 B8-9 v7-x<. Medium dense, saturated, gray, Silty, fme to medium SAND, some shells 25 SM TERRACE DEPOSITS Very dense, saturated, gray. Clayey, finelo coarse SANDSTONE -No recovery 50/4" SC 98/10" -No recovery 60/6" BORING TERMINATED AT 4] FEET Groundwater encountered at 8 feet Hole filled with 40 gal. of bentonite slurry Figure A-8, 2 of 2 7353-22-01, GPJ SAMPLE SYMBOLS D „, SAMPLING UNSUCCESSFUL c. , STANDARD PENETRATION TEST • . DRIVE SAMPLE (UNDISTURBED) ^ ,.. DISTURBED OR BAG SAMPLE B, , CHUNK SAMPLE , WATER TABLE OR SEEPAGE NOTE THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED, IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. PROJECT NO. 07353-22-01 DEPTH IN FEET SAMPLE NO. SOIL CLASS (USCS) BORING B 9 ELEV. (MSL.) _ EQUIPMENT -12 DATE COMPLETED 08-27-2004 MUD ROTARY 2 U r-K Z LL. < < t3 a: P g I- m > UJ Tn O -r UJ I >-fc ll cc a Is o z ^8 - 0 r 2 - 4 - MATERIAL DESCRIPTION UNDOCUMENTED FILL/ALLUVIUM Loose, moisl, brown. Clayey, fine lo coarse SAND SC Dense, moist, red-brown, Silty, fine to coarse SAND, boulders and debris B9-1 - 6 SM 47 BORING TERMINATED AT 6 FEET No groundwater encountered Hole filled with cuttings mixed with bentonite Figure A-9, 7353-22-01. GPJ Log of Boring B 9, Page 1 of 1 SAMPLE SYMBOLS ° " ^^^UCCESSFUL B .„ STANDARD PENETRATION TEST 1 ... DRIVE SAMPLE (UNDISTURBED) ^ ... DISTURBED OR BAG SAMPLE ikl „, CHUNK SAMPLE I ,. WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED, IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. PROJECT NO, 07353-22-01 DEPTH IN FEET SAMPLE NO, SOIL CLASS (USCS) BORING B 10 ELEV. (MSL.) -13 EQUIPMENT DATE COMPLETED 08-27-2004 MUD ROTARY 9 O H t- Z U- .< CO CO Vi o z ^. ll cc a - 0 MATERIAL DESCRIPTION - 2 - - 4 - - 6 - - 8 - - 10 - - 12 - - 14 - - 16 - 18 - - 20 - 22 - 24 BlO-l BlO-2 [1 SC y BIO-3 BlO-4 / y_ / / BlO-5 I"! SC SM UNDOCUMENTED FILL/ALLUVIVM Dense, moist, red-brown, Clayey, fine to coarse SAND 46 -Becomes very loose at 5 feet -Becomes saturated al 7 feet Loose, saturated, dark gray to black. Clayey, fine to coarse SAND, slight organic odor -Becomes medium dense 12 Medium dense, saturated, light-tan, Silty, fine SAND 39 TERRACE DEPOSITS Ver^- dense -iamrated nal^-^r^v Clave^• fine to medium SANDSTONF, Figure A-10, Log of Boring BIO, Page 1 of 2 7353-22-01. GPJ SAMPLE SYMBOLS n - SAMPLING UNSUCCESSFUL I] STANDARD PENETRATION TEST • . DRIVE SAMPLE tUNDlSTURBED) ^ ,.. DISTURBED OR BAG SAMPLE £, .CHUNK SAMPLE . WATER TABLE OR SEEPAGE NOTE. THE LOG OF SUBSURFACE CONDmONS SHOWN HEREON APPLIES ONLY ATTHE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATI^/E OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. PROJECT NO. 07353-22-01 DEPTH IN FEET SAMPLE NO. SOIL CLASS (USCS) BORING B 10 ELEV. (MSL.) -13 EQUIPMENT DATE COMPLETED 08-27-2004 MUD ROTARY Ul T o I-Z LL. >-t Z Li- u cc Q oz 5 O o MATERIAL DESCRIPTION BlO-6 60 - 26 - 28 - 30 - SC BlO-7 85 BORING TERMINATED AT 31 FEET Groundwater encountered at 7 feet Hole filled with 40 gal. of bentonite slurry Figure A-10, 7353-22-01.GPJ Log of Boring B 10, Page 2 of 2 SAMPLE SYMBOLS ° ...^"PUNG UNSUCCESSFUL C ... STANDARD PENETRATION TEST 1 .., DRIVE SAMPLE (UNDISTURBED) ^ ... DISTURBED OR BAG SAMPLE K ... CHUNK SAMPLE % •- WATER TABLE OR SEEPAGE NOTE. THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES, APPENDIX M APPENDIX B LABORATORY TESTING Laboratory tests were performed in accordance with generally accepted test methods of the American Society for Testing and Materials (ASTM) or other suggested procedures. Samples were subjected to drained direct shear, grain-size analysis, consolidation, expansion index, R-value, and laboratory maximum dry density and optimum moisture content tests. One sample was tested for its corrosivity characteristics. Results of the grain-size analysis and consolidation tests are presented on Figures Bl through B3. Results of the other laboratory tests are presented on Tables B-1 through B-VI. In situ moisture and dry density tests are presented on the boring logs (Appendix A). TABLE B-1 SUMMARY OF LABORATORY DIRECT SHEAR TEST RESULTS ASTM D 3080-98 Sample No. Dry Density (pcf) Moisture Content (%) Unit Cohesion (psf) Angle of Shear Resistance (degrees) Bl-4 114.5 14.5 630 33 B6-1 106.0 8.0 370 36 TABLE B-II SUMMARY OF LABORATORY EXPANSION INDEX TEST RESULTS ASTM D 4829-95 Sample No. Moisture Content Dry Density (pcf) Expansion Index Sample No. Before Test (%) After Test (%) Dry Density (pcf) Expansion Index B2-5 13.8 36.8 99,7 181 Project No. 07353-22-01 -B-1 -September 3. 2004 TABLE B-lll SUMMARY OF LABORATORY MAXIMUM DRY DENSITY AND OPTIMUM MOISTURE CONTENT TEST RESULTS ASTM D 1557-02 Sample No. Description Maximum Dry Density (pcf) Optimum Moisture Content (% dry wt.) B3-1 Dark brown Silty, fine to coarse SAND 134.0 8.1 TABLE B-IV SUMMARY OF LABORATORY RESISTANCE VALUE TEST RESULTS ASTM D 2844-99 Sample No. Description R-Value Bl-1 Reddish brown Silty, fine to medium SAND with a trace of gravel 65 TABLE B-V SUMMARY OF LABORATORY pH AND RESISTIVITY TEST RESULTS CAUFORNIA TEST METHOD NO. 643 Sample No. pH Minimum Resistivity (ohm-centimete rs) B3-3 6.4 210 TABLE B-VI SUMMARY OF LABORATORY WATER-SOLUBLE SULFATE TEST RESULTS CALIFORNIA TEST METHOD NO. 417 Sample No. Water-Soluble Sulfate (%) B3-3 0.050 Project No. 07353-22-01 -B-2-September 3, 2004 PROJECT NO. 07353-22-01 GRAVEL SAND SILT OR CLAY COARSE FINE COARSE MEDIUM FINE SILT OR CLAY 3" 1-1./2" 3/4" 3/8 U. S. STANDARD SIEVE SIZE 16 100 90 80 ^ 70 O LU 5 60 CD a: UJ 50 ID O LU 40 30 20 10 0 100 200 GRAIN SIZE IN MILLIMETERS 13700 SAMPLE DEPTH (ft) CLASSIFICATION NATWC LL PL PI • 05-3 10.0 Sandy SILT (ML) B7-3 10.0 Clayey SAND (SC) GRADATION CURVE OCEAN STREET CONDOMINIUM CARLSBAD, CALIFORNIA 7353-22-01.GPJ Figure B-1 PROJECT NO. 07353-22-01 SAMPLE NO. B7-4 -6 -4 -2 z g I-< o IJ O o z o o I-z LU O CC UJ CL 10 7. ra APPLIED PRESSURE (ksf) Initial Dry Density (pcf) 105,2 Initial Water Content (%) 14,9 Tt) Initial Saturation (%) 68,6 Sample Saturated at (l(sf) 2.0 CONSOLIDATION CURVE OCEAN STREET CONDOMINIUM CARLSBAD, CALIFORNIA 7353-22-01.GPJ Figure B-2 PROJECT NO. 07353-22-01 SAMPLE NO. B5-2 -6[ -4 -2 2 O ^ Q _i O 1/3 Z O o UJ o a: LU Q. 10 7 TU APPLIED PRESSURE (ksf) Initial Dry Density (pcf) 110.9 Initial Water Content (%) 17.4 t)0 Initial Saturation (%) 93,2 Sample Saturated at (ksf) 2,0 CONSOLIDATION CURVE OCEAN STREET CONDOMINIUM CARLSBAD, CALIFORNIA 7353-22-01. GPJ Figure B-1 APPENDIX M C APPENDIX C RECOMMENDED GRADING SPECIFICATIONS FOR OCEAN STREET CONDOMINIUMS OCEAN STREET AND MOUNTAIN VIEW DRIVE CARLSBAD, CALIFORNIA PROJECT NO. 07353-22-01 RECOMMENDED GRADING SPECIFICATIONS 1. GENERAL 1.1. These Recommended Grading Specifications shall be used in conjunction with the Geotechnical Report for the project prepared by Geocon Incorporated. The recommendations contained in the text of the Geotechnical Report are a part of the earthwork and grading specifications and shall supersede the provisions contained hereinafter in the case of conflict. 1.2. Prior to the commencement of grading, a geotechnical consultant (Consultant) shall be employed for the purpose of observing earthwork procedures and testing the fills for substantial conformance with the recommendations of the Geotechnical Report and these specifications. It will be necessary that the Consultant provide adequate testing and observation services so that he may determine that, in his opinion, the work was performed in substantial conformance with these specifications. It shall be the responsibility of the Contractor to assist the Consultant and keep him apprised of work schedules and changes so that personnel may be scheduled accordingly. 1.3. It shall be the sole responsibility of the Contractor to provide adequate equipment and methods to accomplish the work in accordance with apphcable grading codes or agency ordinances, these specifications and the approved grading plans. If, in the opinion of the Consultant, unsatisfactory conditions such as questionable soil materials, poor moisture condition, inadequate compaction, adverse weather, and so forth, result in a quality of work not in conformance with these specifications, the Consultant will be empowered to reject the work and recommend to the Owner that construction be stopped until the unacceptable conditions are corrected. 2. DEFINITIONS 2.1. Owner shall refer to the owner of the property or the entity on whose behalf the grading work is being performed and who has contracted with the Contractor to have grading performed. 2.2. Contractor shall refer to the Contractor performing the site grading work. 2.3. Civil Engineer or Engineer of Work shall refer to the Califomia licensed Civil Engineer or consulting firm responsible for preparation of the grading plans, surveying and verifying as-graded topography. GI rev. 07/02 2.4. Consultant shall refer to the soil engineering and engineering geology consulting firm retained to provide geotechnical services for the project. 2.5. Soil Engineer shall refer to a Califomia hcensed Civil Engineer retained by the Owner, who is experienced in the practice of geotechnical engineering. The Soil Engineer shall be responsible for having qualified representatives on-site to observe and test the Contractor's work for conformance with these specifications. 2.6. Engineering Geologist shall refer to a Califomia licensed Engineering Geologist retained by the Owner to provide geologic observations and recommendations during the site grading. 2.7. Geotechnical Report shall refer to a soil report (including all addenda) which may include a geologic reconnaissance or geologic investigation that was prepared specifically for the development of the project for which these Recommended Grading Specifications are intended to apply. 3. MATERIALS 3.1. Materials for compacted fill shall consist of any soil excavated from the cut areas or imported to the site that, in the opinion of the Consultant, is suitable for use in construction of fills. In general, fill materials can be classified as soil fills, soil-rock fills or rock fills, as defined below. 3.1.1. Soil fills are defined as fills containing no rocks or hard lumps greater than 12 inches in maximum dimension and containing at least 40 percent by weight of material smaller than 3/4 inch in size. 3.1.2. Soil-rock fills are defmed as fills containing no rocks or hard lumps larger than 4 feet in maximum dimension and containing a sufficient matrix of soil fill to allow for proper compaction of soil fill around the rock fragments or hard linnps as specified in Paragraph 6.2. Oversize rock is defined as material greater than 12 inches. 3.1.3. Rock fills are defined as fills containing no rocks or hard lumps larger than 3 feet in maximum dimension and containing little or no fines. Fines are defined as malerial smaller than 3/4 inch in maximum dimension. The quantity of fines shall be less lhan approximately 20 percent of the rock fill quantity. GI rev. 07/02 3.2. Material of a perishable, spongy, or otherwise unsuitable nature as determined by the Consultant shall not be used in fills. 3.3. Materials used for fill, either imported or on-site, shall not contain hazardous materials as defmed by the Caiifomia Code of Regulations, Title 22, Division 4, Chapter 30, Articles 9 and 10; 40CFR; and any other apphcable local, state or federal laws. The Consultant shall not be responsible for the identification or analysis of the potential presence of hazardous materials. However, if observations, odors or soil discoloration cause Consultant to suspect the presence of hazardous materials, the Consultant may request from the Owner the termination of grading operations within the affected area. Prior to resuming grading operations, the Owner shall provide a written report to the Consultant indicating that the suspected materials are not hazardous as defined by applicable laws and regulations. 3.4. The outer 15 feet of soil-rock fill slopes, measured horizontally, should be composed of properly compacted soil fill materials approved by the Consultant. Rock fill may extend to the slope face, provided that the slope is not steeper than 2:1 (horizontal; vertical) and a soil layer no thicker than 12 inches is track-walked onto the face for landscaping purposes. This procedure may be urilized, provided it is acceptable to the goveming agency. Owner and Consultant. 3.5. Representative samples of soil materials to be used for fill shall be tested in the laboratory by the Consultant to determine the maximum density, optimum moisture content, and, where appropriate, shear strength, expansion, and gradation characteristics of the soil. 3.6. During grading, soil or groundwater conditions other than those identified in the Geotechnical Report may be encountered by the Contractor. The Consultant shall be notified immediately to evaluate the significance of the unanticipated condition 4. CLEARING AND PREPARING AREAS TO BE FILLED 4.1. Areas to be excavated and filled shall be cleared and grubbed. Clearing shall consist of complete removal above the ground surface of trees, stumps, brush, vegetation, man-made structures and similar debris. Grubbing shall consist of removal of stumps, roots, buried logs and other unsuitable material and shall be performed in areas to be graded. Roots and other projections exceeding 1-1/2 inches in diameter shall be removed to a depth of 3 feet below the surface of the ground. Borrow areas shall be grubbed to the extent necessary to provide suitable fill materials. 01 rev. 07/02 4.2. Any asphalt pavement material removed during clearing operations should be properly disposed at an approved off-site facility. Concrete fragments which are free of reinforcing steel may be placed in fills, provided they are placed in accordance with Section 6.2 or 6.3 of this document. 4.3. After clearing and grubbing of organic matter or other unsuitable material, loose or porous soils shall be removed to the depth recommended in the Geotechnical Report. The depth of removal and compaction shall be observed and approved by a representative of the Consultant. The exposed surface shall then be plowed or scarified to a minimum depth of 6 inches and until the surface is free from uneven features that would tend to prevent unifonn compaction by the equipment to be used. 4.4. Where the slope ratio of the original ground is steeper than 6:1 (horizontahverrical), or where recommended by the Consultant, the original ground should be benched in accordance with the following illustration. TYPICAL BENCHING DETAIL Finish Grade Original Ground Finish Slope Surface Remove All Unsuitable Material As Recommended By Soil Engineer Slope To Be Such That Sloughing Or Sliding Does Not Occur See Note 1 See Note 2—* No Scale DETAIL NOTES: (1) Key width "B" should be a minimum of 10 feet wide, or sufficiently wide to perniit complete coverage with the compaction equipment used. The base of the key should be graded horizontal, or inclined slightly into the natural slope. (2) The outside of the bottom key should be below the topsoil or unsuitable surficial material and at least 2 feet into dense formational material. Where hard rock is exposed in the bottom of the key, the depth and configuration of the key may be modified as approved by the Consultant. GI rev. 07/02 4.5. After areas to receive fill have been cleared, plowed or scarified, the surface should be disced or bladed by the Contractor until it is uniform and free from large clods. The area should then be moisture conditioned to achieve the proper moisture content, and compacted as recommended in Section 6.0 of these specifications. 5. COMPACTION EQUIPMENT 5.1. Compaction of soil or soil-rock fill shall be accomplished by sheepsfoot or segmented-steel wheeled rollers, vibratory rollers, multiple-wheel pneumatic-tired rollers, or other types of acceptable compaction equipment. Equipment shall be of such a design that it will be capable of compacting the soil or soil-rock fill to the specified relative compaction at the specified moisture content. 5.2. Compaction of rock fills shall be performed in accordance with Section 6.3. 6. PLACING, SPREADING AND COMPACTION OF FILL MATERIAL 6.1. Soil fill, as defined in Paragraph 3.1.1, shall be placed by the Contractor in accordance with the following recommendations: 6.1.1. Soil fill shall be placed by the Contractor in layers that, when compacted, should generally not exceed 8 inches. Each layer shall be spread evenly and shall be thoroughly mixed during spreading to obtain uniformity of material and moisture in each layer. The entne fill shall be constmcted as a unit in nearly level lifts. Rock materials greater than 12 inches in maximum dimension shall be placed in accordance with Section 6.2 or 6.3 of these specifications. 6.1.2. In general, the soil fill shall be compacted at a moisture content at or above the optimum moisture content as deteimined by ASTM D1557-00. 6.1.3. When the moisture content of soil fill is below that specified by the Consultant, water shall be added by the Contractor until the moisture content is in the range specified. 6.1.4. When the moisture content of the soil fill is above the range specified by the Consultant or too wet to achieve proper compaction, the soil fill shall be aerated by the Contractor by blading/mixing, or other satisfactory methods until the moisture content is within the range specified. GI rev. 07/02 6.1.5. After each layer has been placed, mixed, and spread evenly, it shall be thoroughly compacted by the Contractor to a relative compaction of at least 90 percent. Relative compaction is defined as the ratio (expressed in percent) of the in-place dry density of the compacted fill to the maximum laboratory dry density as determined in accordance with ASTM D1557-00. Compacfion shall be continuous over the entire area, and compaction equipment shall make sufficient passes so that the specified minimum relative compaction has been achieved throughout the entire fill. 6.1.6. Soils having an Expansion Index of greater than 50 may be used in fills if placed at least 3 feet below finish pad grade and should be compacted at a moisture content generally 2 to 4 percent greater than the optimum moisture content for the material. 6.L7. Properly compacted soil fill shall extend to the design surface of fill slopes. To achieve proper compacfion, it is recommended that fill slopes be over-built by at least 3 feet and then cut to the design grade. This procedure is considered preferable to track-walking of slopes, as described in the following paragraph. 6.1.8. As an altemafive to over-building of slopes, slope faces may be back-rolled with a heavy-duty loaded sheepsfoot or vibratory roller at maximum 4-foot fill height intervals. Upon completion, slopes should then be track-walked with a D-8 dozer or similar equipment, such that a dozer track covers all slope surfaces at least twice. 6.2. Soil-rock fill, as defined in Paragraph 3.1.2, shall be placed by the Contractor in accordance with the following recommendations: 6.2.1. Rocks larger than 12 inches but less than 4 feet in maximum dimension may be incorporated into the compacted soil fill, but shall be limited to the area measured 15 feet minimum horizontally from the slope face and 5 feet below fmish grade or 3 feet below the deepest utility, whichever is deeper. 6.2.2. Rocks or rock fragments up to 4 feet in maximum dimension may either be individually placed or placed in windrows. Under certain conditions, rocks or rock fragments up to 10 feet in maximum dimension may be placed using similar methods. The acceptability of placing rock materials greater than 4 feet in maximum dimension shall be evaluated during grading as specific cases arise and shall be approved by the Consultant prior to placement. GI rev. 07/02 6.2.3. For individual placement, sufficient space shall be provided between rocks to allow for passage of compacfion equipment. 6.2.4. For windrow placement, the rocks should be placed in trenches excavated in properly compacted soil fill. Trenches should be approximately 5 feet wide and 4 feet deep in maximum dimension. The voids around and beneath rocks should be filled with approved granular soil having a Sand Equivalent of 30 or greater and should be compacted by flooding. Windrows may also be placed utilizing an "open-face" method in Heu of the trench procedure, however, this method should first be approved by the Consultant. 6.2.5. Windrows should generally be parallel to each other and may be placed either parallel to or perpendicular to the face of the slope depending on the site geometry. The minimum horizontal spacing for windrows shall be 12 feet center-to-center with a 5-foot stagger or offset from lower courses to next overlying course. The minimum vertical spacing between windrow courses shall be 2 feet from the top of a lower windrow to the bottom of the next higher windrow. 6.2.6. All rock placement, fill placement and fiooding of approved granular soil in the windrows must be continuously observed by Ihe Consultant or his representative. 6.3. Rock fills, as defmed in Section 3.1.3., shall be placed by the Contractor in accordance with the following recommendafions: 6.3.1. The base of the rock fill shall be placed on a sloping surface (minimum slope of 2 percent, maximum slope of 5 percent). The surface shall slope toward suitable subdrainage outlet facihties. The rock fills shall be provided with subdrains during construcfion so that a hydrostafic pressure buildup does not develop. The subdrains shall be permanemly connected to controlled drainage facilifies to control post- constmction infiltrafion of water. 6.3.2. Rock fills shall be placed in lifts not exceeding 3 feet. Placement shall be by rock tmcks traversing previously placed lifts and dumping at the edge of the cim-ently placed lift. Spreading of the rock fill shall be by dozer to facilitate seating of the rock. The rock fill shall be watered heavily during placement. Watering shall consist of water tmcks traversing in front of the current rock lift face and spraying water continuously during rock placement. Compacfion equipment with compactive energy comparable to or greater than that of a 20-ton steel vibratory roller or other compaction equipment providing suitable energy to achieve the required compaction or deflection as recommended in Paragraph 6.3.3 shall be ~ ~ GI rev. 07/02 ufilized. The number of passes to be made will be determined as described in Paragraph 6.3.3. Once a rock fill lift has been covered with soil fill, no additional rock fill lifts will be permitted over the soil fill. 6.3.3. Plate bearing tests, in accordance wifii ASTM Dl 196-93, may be performed in both the compacted soil fill and in the rock fill to aid in determining the number of passes of the compacfion equipment to be performed. If performed, a minimum of three plate bearing tests shall be performed in the properly compacted soil fill (minimum relafive compacfion of 90 percent). Plate bearing tests shall then be performed on areas of rock fill having two passes, four passes and six passes of the compaction equipment, respectively. The number of passes required for the rock fill shall be determined by comparing the results of the plate bearing tests for the soil fill and the rock fill and by evaluating the deflecfion variation with number of passes. The required number of passes of the compacfion equipment will be performed as necessary unfil the plate bearing deflecfions are equal to or less than that determined for the properly compacted soil fill. In no case will the required number of passes be less than two. 6.3.4. A representative of the Consultant shall be present during rock fill operafions to verify that the minimum number of "passes" have been obtained, that water is being properly applied and that specified procedures are being followed. The actual number of plate bearing tests will be determined by the Consultant during grading. In general, at least one test should be performed for each approximately 5,000 to 10,000 cubic yards of rock fill placed. 6.3.5. Test pits shall be excavated by the Contractor so that the Consultant can state that, in his opinion, sufficient water is present and that voids between large rocks are properly filled with smaller rock material. In-place density testing will not be required in the rock fills. 6.3.6. To reduce the potential for "piping" of fines into the rock fill from overiying soil fjll material, a 2-foot layer of graded filter material shall be placed above the uppermost fift of rock fill. The need to place graded filter material below the rock should be determined by the Consultant prior to commencing grading. The gradation of the graded filter material will be determined at the time the rock fill is being excavated. Materials typical of the rock fill should be submitted to the Consultant in a timely manner, to allow design of the graded filter prior to the commencement of rock fill placement. GI rev. 07/02 6.3.7. All rock fill placement shall be continuously observed during placement by representafives of the Consultant. 7. OBSERVATION AND TESTING 7.1. The Consultant shall be the Owners representafive to observe and perform tests during clearing, gmbbing, filling and compaction operations. In general, no more than 2 feet in vertical elevation of soil or soil-rock fill shall be placed without at least one field density test being performed within that interval. In addition, a minimum of one field density test shall be performed for every 2,000 cubic yards of soil or soil-rock fill placed and compacted. 7.2. The Consultant shall perform random field density tests of the compacted soil or soil-rock fill to provide a basis for expressing an opinion as to whether the fill material is compacted as specified. Density tests shall be performed in the compacted materials below any disturbed surface. When these tests indicate that the density of any layer of fill or portion thereof is below that specified, the particular layer or areas represented by the test shall be reworked until the specified density has been achieved. 7.3. During placement of rock fill, the Consultant shall verify that the minimum number of passes have been obtained per the criteria discussed in Section 6.3.3. The Consultant shall request the excavation of observation pits and may perform plate bearing tests on the placed rock fills. The observation pits will be excavated to provide a basis for expressing an opinion as to whether the rock fill is properiy seated and sufficient moisture has been applied to the material. If performed, plate bearing tests will be performed randomly on the surface of the most-recently placed lift. Plate bearing tests will be performed to provide a basis for expressing an opinion as to whether the rock fill is adequately seated. The maximum deflection in the rock fill determined in Secfion 6.3.3 shall be less than the maximum deflecfion of the properiy compacted soil fill. When any of the above criteria indicate that a layer of rock fill or any portion thereof is below that specified, the affected layer or area shall be reworked until the rock fill has been adequately seated and sufficient moisture applied. 7.4. A settlement monitoring program designed by the Consultant may be conducted in areas of rock fill placement. The specific design of the monitoring program shall be as recommended in the Conclusions and Recommendations section of the project Geotechnical Report or in the final report of testing and observation services performed during grading. GI Tty. 07/02 7.5. The Consultant shall observe the placement of subdrains, to verify that the drainage devices have been placed and constmcted in substantial conformance with project specifications. 7.6. Testing procedures shall conform to the following Standards as appropriate: 7.6.1. Soil and Soil-Rock Fills: 7.6.1.1. Field Density Test, ASTM D1556-00, Density of Soil In-Place By the Sand-Cone Method. 7.6.1.2. Field Density Test, Nuclear Method, ASTM D2922-96, Density of Soil and Soil-Aggregate In-Place by Nuclear Methods (Shallow Depth). 7.6.1.3. Laboratory Compaction Test, ASTM D1557-00, Moisture-Density Relations of Soils and Soil-Aggregate Mixtures Using JO-Pound Hammer and 18-Inch Drop. 7.6.1.4. Expansion hidex Test, ASTM D4829-95, Expansion Index Test. 7.6.2. Rock Fills 7.6.2.1. Field Plate Bearing Test, ASTM D1196-93 (Reapproved 1997) Standard Method for Nonreparative Static Plate Load Tests of Soils and Flexible Pavement Components, For Use in Evaluation and Design of Airport and Highway Pavements. 8. PROTECTION OF WORK 8.1. During construction, the Contractor shall properiy grade all excavated surfaces to provide positive drainage and prevent ponding of water. Drainage of surface water shall be controlled to avoid damage to adjoining properties or to finished work on the site. The Contractor shall take remedial measures to prevent erosion of freshly graded areas until such time as permanent drainage and erosion control features have been installed. Areas subjected to erosion or sedimentation shall be properly prepared in accordance with the Specifications prior to placing additional fill or stmctures. 8.2. After completion of grading as observed and tested by the Consultant, no further excavation or filling shall be conducted except in conjuncfion with the services of the Consultant GI rev. 07/02 9. CERTIFICATIONS AND FINAL REPORTS 9.1. Upon completion of the work, Contractor shall furnish Owner a certification by the Civil Engineer stating that the lots and/or building pads are graded to within 0.1 foot vertically of elevations shown on the grading plan and that all tops and toes of slopes are within 0.5 foot horizontally of the positions shown on the grading plans. After installation of a section of subdrain, the project Civil Engineer should survey its location and prepare an as-built plan of the subdrain location. The project Civil Engineer should verify the proper outlet for the subdrains and the Contractor should ensure that the drain system is free of obstmctions. 9.2. The Owner is responsible for fumishing a final as-graded soil and geologic report satisfactory to the appropriate goveming or accepting agencies. The as-graded report should be prepared and signed by a Califomia licensed Civil Engineer experienced in geotechnical engineering and by a Califomia Certified Engineering Geologist, indicating that the geotechnical aspects of the grading were performed in substantial conformance with the Specifications or approved changes to the Specificafions. GI rev. 07/02 LIST OF REFERENCES 1. Blake, T. F., EQFAULT, A Computer Program for the Deterministic Prediction of Peak Horizontal Acceleration from Digitized Califomia Faults, Users Manual, 1989a, p. 79 (Revised 1997 and 2000). 2. County of San Diego Topographic Survey, Ortho-photo. Sheet No. 362-1659. Photography dated 1975. 3. Geologic Maps of the Northwestern Part of San Diego County, Califomia. Califomia Division of Mines and Geology Open-file Report 96-02, 1996. 4. United States Department of Agriculture, 1953 Stereoscopic Aerial Photographs, Flight AXN-14M, Photo Nos. 20 and 21. 5. United States Geological Survey, 7.5 minute Quadrangle Series, San Luis Rey Quadrangle, 1968, Photorevised 1975. 6. Unpublished reports, aerial photographs and maps on file with Geocon Incorporated. Project No. 07353-22-01 September 3, 2004 USaglneen'BB ine. DRAFT TralBcantnansBoitatton 6342 Ferris Square, San Diego, CA 92121 Phone 619-890-1253, Fax 619-374-7247 May 2, 2005 Prospect Point Development c/o Tim Clark 1020 Prospect Ave, Suite 314 La Jolla, CA 92037 SUBJECT: Traffic Generation Letter Report for the Ocean Street Residences Redevelopment Project from 50 Apartments to 35 Condominiums Dear Mr. Clark: The following traffic generation letter report has been prepared to document why a traffic study does not appear necessary for this project due to the net decrease in traffic through the redevelopment of 50 apartment units to 35 condominium units. PROJECT LOCATION, DESCRIPTION, AND TRAFFIC GENERATION The project site is located in the northwest quadrant of the City, north of Ocean Sfreet, west of the AT&SF Railroad, south of the Buena Vista Lagoon and east of the Rue Des Chateaux development. The 3.05 acre project site is currently developed with 50 apartments units in three separate buildings (16.4 units per acre) as shown in Figure 1. Access to the existing apartments is provided from Ocean Sfreet via two residential driveways located along the westem and eastem property lines. The project applicant is proposing to demolish the existing apartment buildings on-site and construct 35 new stacked-flat condominium units (11.5 units per acre). Access for the project is proposed to be located at the southwest comer from Ocean Sfreet. A two driveway system will create a vehicular entry court that provides queuing and tum around area for the future residents and their guests as shown in Figure 2. The project is proposing a gated entry along the westem property line that will include the required emergency system for access (ICNOX/Opficon). Using the San Diego Association of Governments (SANDAG) trip rates from the Brief Guide of Vehicular Traffic Generation Rates for the San Diego Region, April 2002, this redevelopment project is calculated to have a net change of-120 Average Daily Traffic (ADT), -10 AM peak hour trips (-2 inbound and -8 outbound), and -12 PM peak hour trips (-8 inbound and -4 outbound) over the existing use as shown in Table 1. usBifflnSdrtttB Ino. ocean Street Redevelopment Project DRAFT Traffic Letter Report TmUICantnSnSnOI^UOn Mr. Clark-May2, 2005 \ Table 1: Project Traffic Generation Land Use AM PM Rate Size & Units ADT % Split IN OUT % Split IN OUT Proposed Condos 8 /Unit 35 Units 280 8% 0.2 0.8 4 18 10% 0.7 0.3 20 8 Existing Apartments 8 /Unit 50 Units -400 8% 0.2 0.8 -6 -26 10% 0.7 0.3 -28 -12 Net Traffic Decrease :120 -2 -8 -8 -4 Source: SANDAG Brief Guide of Vehicular Traffic Generation Rates for ttie San Diego Region, April 2002. TRAFFIC STUDY REQUIREMENTS Traffic studies are typically required by the city of Carlsbad when the project fraffic generation exceeds 500 ADT, fiie applicant requests a change in land use, or the applicant requests an increase in density. On a regional basis, the San Diego Traffic Engineers' Coimcil (SANTEC) and the Institute of Transportation Engineers (ITE - Califomia Border Section) guidelines specify that if a fraffic study is being prepared, the roadways and intersections to be analyzed are only included where the proposed project would add 50 or more peak hour frips. The proposed project does not meet either guideline. CONCLUSIONS A fraffic study for the Ocean Sfreet Residences redevelopment project from 50 apartment to 35 condominiums does not appear necessary because the project: 1) Has a calculated decrease in daily fraffic generafion of-120 ADT, -10 AM peak hour trips, and -12 PM peak hour trips over the existing use, and 2) Has a calculated generation of 22 AM and 28 PM peak hour trips, which is less than the 50 peak hour threshold for analyzing roadways or intersections per the SANTEC/ITE guidelines. Please call me at (619) 890-1253 if you have any quesfions. Sincerely, LOS Engineering, Inc. ustin Rasas, P.E., P.T.O.E. Principal and Officer of LOS Engineering, Inc. Attachments lOSIngineSring, Inc. ocean street Redevelopment Project DRAFT Traffic Letter Report / Traffic and Tmsportailon Mr. Clark - May 2, 2005 FIGURE 1: PROJECT LOCATION SHOWING 50 EXISTING APARTMENT UNITS IBS[ngfnaafing, tnc. ocean street Redevelopment Project DRAFT Traffic Letter Report Traffic ann Transportation Mr. ciark - May 2,2005 FIGURE 2: PROPOSED SITE PUN WITH 35 CONDOMINIUM UNITS