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HomeMy WebLinkAboutCT 03-04; Highland Drive Subdivision; Preliminary Soil and Geology Investigation; 2003-05-21* REPORT PRELIMINARY SOIL AND GEOLOGY INVESTIGATION Proposed Single-Family Residences 3002 Highland Drive Carlsbad, California for A & A Development 2009 Via Teca San Clemente, California 92673 Jeffrey A. Dahl Architect Project No. HA-4871-2 May 21, 2003 HU ASSOCIATES, INC. GEOTECHNICAL / ENVIRONMENTAL ENGINEERING CONSULTANTS 11955 RIVERA ROAD • SANTA FE SPRINGS, CA 90670-2209 • TELEPHONE (562) 696-6062 (562)693-6114 FAX (562) 698-5771 May 21,2003 HA-4871-2 A & A Development 2009 Via Teca San Clemente, California 92673 Attention: Mr. Greg Strange SUBJECT:PRELIMINARY SOIL AND GEOLOGY INVESTIGATION Proposed Single-Family Residences 3002 Highland Drive Carlsbad, California Gentlemen: In accordance with our proposal of April 08, 2003, we have conducted a preliminary soil and geology investigation for the proposed single-family residences to be located at 3002 Highland Drive in the City of Carlsbad, County of San Diego, California. Based on the findings and observations of this investigation, it is concluded that the proposed development of the subject property for the intended use is feasible from the geotechnical engineering viewpoint, provided the specific recommendations set forth herein are followed. The proposed structures may be supported by conventional spread footings rested on undisturbed natural and/or compacted soils. The accompanying report represents relevant conclusions and recommendations for the preliminary planning and foundation designs. We thank you for entrusting us to undertake this investigation and look forward to future association. If any questions arise concerning the interpretation of the report, please do not hesitate to call. Very truly yours, HU ASSOCIATES, INC. ichar^A Hu, Ph.D. President REH/ps ,m REPORT PRELIMINARY SOIL AND GEOLOGY INVESTIGATION PROPOSED SINGLE-FAMILY RESIDENCES 3002 HIGHLAND DRIVE CARLSBAD, CALIFORNIA FOR A & A DEVELOPMENT INTRODUCTION The following report presents the results of a preliminary soil and geology investigation conducted on the properties located at 3002 Highland Drive, in the City of Carlsbad, County of San Diego, California. The location of the site relative to surrounding streets and landmarks is shown on Plate 1, Vicinity Map. The purpose of this investigation was to obtain the geotechnical engineering properties of the subsurface soils at the subject site on which to base conclusions and recommendations for foundations support and other geotechnical matters pertinent to the proposed construction. Implementation of the recommendations made in this report is intended to reduce certain risks associated with construction projects. The scope of this investigation does not include the work related in any way to identify asbestos and/or hazardous waste material. This report has been prepared for use in design of the described project. It may not contain sufficient information for other purposes. Our professional services have been performed in accordance with generally accepted engineering procedures under similar circumstances. No other warranty, expressed or implied, is made as to the professional advice included in this report. HU ASSOCIATES, INC. HA-4871-2 May 21, 2003 -2- PROPOSED CONSTRUCTION It is understood that the subject property will be utilized for the development of seven (7) new single-family residences at the locations shown on Plate 2. The proposed structures will be two- story in height, constructed of wood frame and stucco with slab on grade. The existing houses near the center of the lot will be removed for new constructions. According to the "Grading Plan" prepared by Melchior Land Surveying, Inc., dated April 11, 2003, fill and cut operations will be required to develop the level building pads and to provide proper site drainage. Maximum cut and fill depths for each pad are summarized as follows: Pad No. 1 2 3 4 5 6 7 Proposed Finish Pad Grade (feet) 168.7 172.9 173.7 173.1 166.5 161.6 158.7 Operation Cut/Fill Cut Cut Fill Fill Fill Fill Maximum Cut Depth (feet) 5 4 3 - - - - Maximum Fill Depth (feet) 3 - - 7 7 6 5 Fill slopes up to 8 feet in height at a gradient of 2 to 1 (horizontal to vertical) are proposed between Highland Drive and Pad 1 and between other lots, as well as along Carlsbad Village Drive. Minor cut slope is also proposed along a portion of the north property line. A retaining wall up to 4 feet in height is proposed at the toe of the proposed cut slope. A new street leading to all the lots will be constructed along the north side of the property. HU ASSOCIATES, INC. HA-4871-2 May 21, 2003 -3- FIELD EXPLORATIONS AND LABORATORY TESTING Field explorations were performed to establish the geotechnical conditions of the site. Six test pits were excavated at the locations shown on Plate 2. The explorations were logged by our field engineer and relatively undisturbed samples were obtained for laboratory testing and inspection. A detailed description of the exploration procedures and the logs of test pits are presented in the Appendix. Laboratory tests were performed to evaluate static soil properties. A description of the test procedures and the test results are also presented in the Appendix. GEOLOGIC SETTING The San Diego County region lies within the Peninsular Range Province of California. This province is a well-defined geological and physiographic unit extending southeastward from the Los Angeles Basin to the tip of Baja California. A copy of the regional geologic map is shown on Plate 2a. The site is situated in the costal zone of San Diego County approximately 2 miles east of the Pacific Ocean. The principal geological unit in the vicinity of the site is nearly flat lying beveled Tertiary sandstone and mudstone. The site appears geologically stable since no known active faults are present within the site. SITE CONDITIONS The subject properties are located on the northeast corner of Highland Drive and Carlsbad Village Drive in the City of Carlsbad, County of San Diego, California. The site is bordered by one-story single-family residences to the east and by a two-story single-family residence to the north. HU ASSOCIATES, INC. HA-4871-2 May 21, 2003 -4- The site consists of two near rectangular-shaped residential lots approximately 190 feet wide by 600 feet deep totally in plan dimensions. The site ascends gently from Highland Drive approximately 15 feet over a horizontal distance of approximately 180 feet and then descends gently to the east property line with a relief of 24 feet over 400 feet horizontal distance. At the time of this investigation, two one-story houses and storage shed occupied the site. Surface vegetation at the site consisted of heavy growth of grasses and few trees. Cross sections showing the existing and proposed grades of the constructions are depicted on Plates 3 and 4. SUBSURFACE SOILS AND GEOLOGIC CONDITIONS Soil Conditions The subsurface materials at the site disclosed at the test pits consist of natural soil and sandstone bedrock. Natural Soil The natural soil was encountered in all of the test pits to depths of 3 to 6 feet. It consists of medium dense to dense, fine to medium, slightly clayey to clayey, silty sand. Bedrock The bedrock at the site consists of Clastic sedimentary rock of Tertiary age. It consists of poorly to well-cemented sandstone. The bedrock encountered in the test pits is generally massive and without obvious bedding structures. HU ASSOCIATES, INC. HA-4871-2 May 21,2003 Groundwater -5- No groundwater or seepage was observed in any of the test pits penetrated to a maximum depth of 10 feet. Groundwater is not anticipated within depths pertinent to future development. It must be noted that fluctuations in the level of the groundwater may occur due to variations in rainfall, temperature, and other factors not evident at the time measurements were made and reported herein. GEOTECHNICAL ENGINEERING HAZARDS Expansive Soil On-site soil materials exhibit low expansion potentials as determined by the Uniform Building Code Standard Test No. 18-1. No special considerations required for design of footings, slabs, or any other structures in contact with these materials other than those given in the following sections of this report. Hydroconsolidation Based on the results of consolidation tests as shown on Plates A-7 through A-9, the onsite subsurface soils are relatively dense. Provided grading of the site is performed as recommended, the potential hydroconsolidation of the underlying natural soil is negligible. Thus it should have no significant impact to the foundation of the proposed structures. Landslides The topography of the subject property and surrounding areas are relatively flat. No landslides are expected. HU ASSOCIATES, INC. HA-4871-2 May 21,2003 -6- EARTHQUAKE HAZARDS Seismicity The subject property lies within the seismically active southern California region. As with all sites in southern California, the site is expected to experience ground shaking from both near and distant earthquake sources during the life of the proposed structure. The type and magnitude of seismic hazard affecting the site are dependent on the distance of causative faults and the intensity and magnitude of the seismic event. Surface Rupture The site is not located within a currently designated Alquist-Priolo Earthquake Fault Zone. No faults, active or potentially active, are known to exist within the site. The probability of surface rupture at the site is, therefore, considered very low. Ground Shaking The closest fault to the site is the Rose Canyon Fault located at approximately 8.8 km to the southwest of the site. It is our opinion that the intensity of future ground shaking at the site is not expected to be greater than any other sites in the immediate vicinity. The proposed structures shall be designed in accordance with the Earthquake Regulations of the Uniform Building Code and the seismic design parameters provided in the other section of this report. Seismically induced Settlement Dynamic compaction of dry and loose sands may occur during a major earthquake. Typically settlements occur in thick beds of such soils. Due to the dense and fine-grained nature of the site soils, excessive dynamic settlements are not expected subsequent to the recommended grading. HU ASSOCIATES, INC. HA-4871-2 May 21,2003 Soil Liquefaction -7- Earthquake-induced liquefaction is a phenomenon in which loose to medium dense saturated cohesionless soils undergo extreme losses in shear strength due to earthquake shaking. The liquefaction potential is directly related to the groundwater conditions at the site, as well as to the characteristics of the underlying soil deposits. Loose to medium dense sands below groundwater level are generally considered to be susceptible to liquefaction under strong ground shaking conditions. The site is not located in the area as delineated by the State Geologist to have potential of soil liquefaction during strong earthquakes. As the onsite materials consist primarily of dense silty sand underlain by bedrock, it is our opinion that potential for liquefaction at the subject property is considered very low. Earthquake-Induced Flooding This is flooding caused by failure of dams or other water-retaining structures up gradient of the site as a result of an earthquake. Review of the area adjacent to the site-indicates that there are no significant up-gradient lakes or reservoirs with the potential of flooding the site. Tsunamis and Seiches Tsunamis are tidal waves generated by fault displacement or major ground movement below the ocean. The site is located at approximately two mile from Pacific Ocean and at an elevation of approximately 160 feet above mean sea level, they will have no effect on the subject property. Seiches are large waves generated in enclosed bodies of water in response to ground shaking. No major water-retaining structures are located immediately up gradient from the project site. The risk of flooding from a seismically induced seiche is considered to be remote. HU ASSOCIATES, INC. HA-4871-2 May 21,2003 -8- CONCLUSIONS AND RECOMMENDATIONS General Based on an evaluation of the site conditions and findings of this investigation, it is concluded that the subject property is suitable for the proposed developments from a geotechnical engineering viewpoint provided the following conclusions and recommendations are incorporated into design criteria and project specifications and are implemented during construction. Conventional spread footings rested on undisturbed natural and/or compacted soils will provide adequate support for the proposed structures. Site Preparation General Precautions should be taken during the performance of all work under the following sections, especially if construction is performed during the rainy season of approximately October 15 to April 15. Protection should be provided to the work site, particularly excavated areas, from flooding, ponding, and inundation due to poor or improper temporary surface drainage. During periods of impending inclement weather, temporary provisions should be made to adequately direct surface drainage, from all sources, away from and off the work site and to provide adequate pumps and sumps to handle any flow into the excavations. Site Clearing Clearing and grubbing should consist of the removal of vegetation such as brush, grass, woods, stumps, trees, roots of trees and otherwise deleterious natural materials from the areas to be graded. Clearing and grubbing should extend to the outside of all proposed excavation and fill areas. HU ASSOCIATES, INC. HA-4871-2 May 21,2003 -9- Debris generated during clearing, grubbing and/or demolition operations should be wasted from areas to be graded and disposed of off-site. During site grading, laborers should clear any roots, tree branches, and other deleterious materials missed during clearing and grubbing operations from all areas to receive fill. The depths of excavation should be reviewed by the Soils Engineer during actual construction. Any surface or subsurface obstructions, or questionable material, encountered during grading should be brought immediately to the attention of the Soils Engineer for proper exposure, removal or processing as directed. No underground obstructions or facilities should remain in any structural areas. Existing Structures Demolition and/or removal of the existing structures are to include removal of the supporting foundation system. Existing paving and concrete slabs should be removed from the site. Utilities Any underground utilities that are not to be reconnected should be cut off a minimum of 4 feet beyond the edge of building perimeters and entirely removed from within the area of future construction. The ends of cut-off lines should be plugged a minimum of 5 feet with concrete exhibiting minimum shrinkage characteristics to prevent water migration to or from hollow lines. In addition, capping of lines may be required should the plug be subject to any line pressures. Existing On-Site Sewage System The location of the existing on-site sewage system (septic tank, seepage pits/cesspools), if any, should be determined. HU ASSOCIATES, INC. HA-4871-2 May 21, 2003 -10- Excavate and remove completely any underground tanks within areas of proposed construction. Contaminated soils resulting from leakage and tank removal will not be suitable for use as structural backfill and should be disposed of off site. Trees and Surface Vegetation Removal of designated trees and shrubs in areas of proposed construction should include rootballs. Resultant cavities should be cleansed of loose soils and roots and rolled to a firm unyielding surface prior backfilling. Grass and weed growth in areas of future construction should be stripped and disposed of off site. Stripping should penetrate three to six inches into surface soils. Any soils sufficiently contaminated with organic matter (such as root systems or stripping mixed into the soils) so as to prevent proper compaction shall be disposed of off site or set aside for future use in landscape areas. Subgrade Preparation Prior to receiving of new fill or where compacted fill is to provide support of structural loads, it is recommended that all loose or disturbed surface natural soils within the proposed construction areas be removed to underlying competent natural soil and replaced with properly compacted fill. The exposed bottom surface in each removal area should first be scarified to a depth of at least 8 inches, processed, watered or air dried as necessary to achieve near optimum moisture conditions, and then compacted in-place to at least 90 percent of the maximum laboratory density. Based on the results of our field investigation, it is anticipated the depth of removal ranged from one to two feet. Locally, some areas exposing loose or soft soils may require deeper removal than indicated above. Actual depth of removal is to be determined in the field at the time of grading. HU ASSOCIATES, INC. HA-4871-2 -11- May 21,2003 Soil/Bedrock Transition To minimize the effects of differential soil movement, soil/bedrock transition zones should be eliminated from the building pad. This could be accomplished by over-excavating the entire pad area to a depth of 3 feet below the base of the foundation or 18 inches below the slab subgrade and replacing the excavated materials as compacted fill for footing or slab support. Fill Placement All new fill shall be brought to near optimum moisture, placed in layers not exceeding 8 inches thick, and compacted to at least 90 percent of the maximum laboratory density. Compaction characteristics of all fill soils shall be determined by ASTM D-1557-00 standard. The field density and degree of compaction shall be determined by ASTM D-1556, or by other ASTM standard methods, which are acceptable to the governing public agency. Fill Slope Fill slopes have been proposed at various locations of the project. Where placement of a fill slope is proposed, a key should be constructed at the toe of the fill slope. The key should be a minimum width equal to 1.5 times the equipment width and be extended at least 2 feet into competent natural soil. Prior to the placement of fill slope, the existing unsuitable soils within the proposed slope area should be removed to underlying competent natural soil. As the replacement fill is brought up in layers, the sloping natural ground surface should be benched to remove weak and compressible soils, and to properly tie the fill to the competent natural soil. HU ASSOCIATES, INC. HA-4871-2 May 21,2003 -12- Key and bench construction requirements and the fill slope configuration as illustrated in the accompanying Standard Detail on Plate 5 should be adopted. A backdrain may be required as directed in the field during grading. The backdrain, if necessary, should be constructed in accordance with Plate 6. The keyway excavation should be carefully examined by the project soils engineer during excavation. The depth of the keyway given above should be considered as a minimum and may be modified during construction if additional unfavorable geologic conditions are encountered. Seismic Design Parameters Based on the results of this preliminary soil investigation and in accordance with Chapter 16, Division IV of the 1997 Uniform Building Code, the following seismic data are applicable to the subject site. Seismic Zone Factor, Z Soil Profile Type Seismic Source Type Near-Source Factor, Na Near-Source Factor, Nv Seismic Coefficient, Ca Seismic Coefficient, Cv 0.4 SD B 1.00 1.05 0.44 0.67 Foundation Recommendations Allowable Bearing Value Provided the subgrade soils are prepared as recommended, an allowable bearing value of 2000 pounds per square foot is recommended for spread footings of at least 15 inches in width, placed at a depth of at least 1.5 feet below the lowest adjacent final grade, rested on undisturbed natural and/or compacted soils. HU ASSOCIATES, INC. HA-4871-2 May 21, 2003 -13- This value may be increased by 100 pounds per square foot for each additional foot in width and 250 pounds per square foot for each additional foot in depth over the minimum, to a maximum of 2500 pounds per square foot. Refer to the subgrade preparation section of this report for removal and recompaction of the onsite soils for footing support. Foundation Settlement Maximum ultimate settlement of footings up to 3 feet wide continuous and 5 feet square or diameter under the recommended bearing pressure is not expected to exceed 3/4 an inch. Differential settlement between adjacent footings is not expected to exceed 1/4 of an inch within a span of 30 feet. Settlement will be approximately in direct proportion to the width of the footings and actual applied load. Footing Reinforcement Continuous footings should be reinforced with at least two No. 5 bars, one near the top and one near the bottom of the footings. Reinforcement of isolated footings and piers or piles shall be utilized as deemed necessary by the Structural Engineer for the project. This reinforcement is based on soil characteristics and is not intended to be in lieu of reinforcement necessary to satisfy structural considerations. Foundation Inspections All foundation excavations should be inspected and approved by the Soils Engineer prior to placement of forms, reinforcement or concrete. The excavations should be trimmed neat, level and square. All loose, sloughed and moisture softened materials should be removed prior to the placement of concrete. HU ASSOCIATES, INC. HA-4871-2 May 21, 2003 -14- Materials from foundation excavations should not be spread in slab-on-grade areas unless they are compacted and tested. Footings should be located below a line measured upward at a 45-degree angle from the bottom of the adjacent footings or utility trench, unless reviewed and approved by the Soils Engineer. Lateral Design An allowable lateral bearing value against the sides of footings of 250 pounds per square foot per foot of depth, to a maximum of 2500 pounds per square foot, may be used provided there is positive contact between the vertical bearing surface and undisturbed natural and/or compacted soils. Friction between the base of the footings and/or floor slabs and the underlying soil may be assumed to be 0.4 times the dead load. When combining passive pressure and friction for lateral resistance, the passive component should be reduced by one-third. Slabs On Grade Floor Slabs Slabs on grade should be cast over properly prepared subgrade. Any loosened or over- excavated soils should be wasted from the site or properly compacted in-place. Subgrade soils disturbed due to installation of utility lines should either be completely removed or be properly compacted prior to concrete pour. The subgrade fill soils should be moisture- conditioned to obtain near optimum water content and then compacted to at least 90 percent of the maximum dry density as determined by the ASTM D-1557-00 compaction test method. HU ASSOCIATES, INC. HA-4871-2 May 21,2003 -15- It should be recognized that minor cracks normally occur in concrete slabs due to shrinkage during curing or redistribution of stresses and thus, some cracks should be anticipated. Such cracks are not necessarily indicative of excessive vertical movements. Slab Reinforcement Floor slabs constructed on-grade should be a minimum thickness of 4 inches and be reinforced with at least No. 4 bars spaced 24 inches on centers, both ways. All slab reinforcement should be supported on concrete chairs or brick to ensure the desired placement near mid-depth. The above criteria are recommended to minimize potential distress to floor slabs related to the effects of subgrade soil conditions. The Structural Engineer for the project may need to address other factors that may require modification of the above recommendations. Moisture Barrier A moisture barrier beneath slabs-on-grade, consisting of a waterproof vapor barrier, such as a plastic membrane of at least 10 mils in thickness, is recommended in areas where slab moisture would be detrimental. The membrane should be overlain by a minimum of 2 inches of clean sands to provide a working surface and aid in concrete curing. It is important that the soil subgrade, which will support the concrete slab, is maintained at the "as-graded" or has a sufficient soil water content. Prior to slab construction, the water content of the soil subgrade should be measured to verify that the subgrade has not dried out significantly. It is suggested that slab areas be thoroughly moistened prior to placing of moisture barrier and pouring of concrete. HU ASSOCIATES, INC. HA-4871-2 May 21,2003 -16- Retaininq Wall Wall Foundation Footings of non-structural retaining wall footings rested on undisturbed natural and/or compacted soils may be designed for an allowable bearing value of 2000 pounds per square foot. The base of the footing is considered at a depth of at least one below the lowest adjacent ground surface. Active Earth Pressures Retaining walls should be designed to resist the lateral earth pressure exerted by the retained soils plus any additional lateral forces that will be applied to the walls due to surface loads placed at or near the wall or from footings behind the walls. It is recommended that retaining walls that are free to rotate at the top be designed for the following: Backfill Slope Gradient (Horizontal to Vertical) Level 5 to1 4 to 1 3 to 1 2 to 1 Equivalent Fluid Pressure (pen 35 37 40 43 45 The recommended earth pressures above are for wall retaining drained earth backfill. A permanent drainage system shall be installed so that hydrostatic water pressure will not be developed against the walls. If a drainage system is not provided, the walls should be designed to resist an external hydrostatic pressure due to water in addition to the lateral earth pressure. HU ASSOCIATES, INC. m HA-4871-2 May 21, 2003 Wall Drainage -17- All retaining walls should be waterproofed and/or damp-proofed, depending on the desired moisture protection. The walls should be provided with weep holes or perforated pipe and gravel subdrain to prevent entrapment of water in the backfill. Weep holes should consist of unmortared joints in block walls or two-inch diameter round holes in poured concrete walls. The openings should be at least 3 inches above finished grade to prevent surface water from flowing back into the holes. Any water that may accumulate in the drainage material should be collected and discharged by a 4-inch diameter, perforated PVC Schedule 40 or ABS SDR-35 pipe placed near the bottom of the drainage material but at least one foot below the interior floor. The pipe should be embedded in drainage material up to two-third of wall height. Pipe perforations shall be at 45- degree angles (approximately) to one another on opposing sides of the pipe every 8 to 12 inches. The pipe perforations should be placed with the holes down, and should not be greater than 1/4 inch in diameter. The subdrain should outlet at appropriate discharge locations that will ensure all discharge will not scour or erode the surrounding soil, and the pipe will not become damaged or clogged. The outlet pipe should be a solid pipe that meets minimum specification set forth above for the subdrain pipe. The drainage material that will be used to backfill the wall should consist of 3/4 to 1-1/2 inch clean durable, coarse aggregate. The drainage material should be separated from all adjacent soil by Mirafi 140NL, or approved equivalent. The fabric should be handled in accordance with the respective manufacturers requirements, and should be constructed such that all fabric overlaps are a minimum of 12 inches. HU ASSOCIATES, INC. HA-4871-2 -18- May 21,2003 Wall Backfill Prior to backfilling, the excavation between retaining walls and the temporary cut bank should be cleared of all loose materials, debris, and construction materials, etc. All of the existing uncertified fills should be completely removed to underlying native soil. Proper compaction of the backfill will be necessary to reduce settlement of the backfill. Some settlement of the backfill should be anticipated and any utilities and sidewalks supported therein should be designed to accept differential settlement, particularly at the points of entry to the structure. All wall backfill should be placed in horizontal lifts not more than 8 inches in thickness, watered as necessary to achieve near optimum moisture conditions, and mechanically compacted to at least 90 percent of the ASTM D-1557-00 standard. Flooding or jetting of backfill materials should be avoided. Probing and testing should be performed by the project soils engineer to verify proper compaction. Where the ground slope is steeper than 5 horizontal to 1 vertical, the existing ground shall be benched as the fill thereon is brought up in layers. Where space limitations do not allow for conventional backfill compaction operations, the space should be backfilled with pea gravel. The pea gravel backfill should be placed in lifts of no more than 2 feet in thickness and should be compacted with vibratory equipment. Ideally, the top of two feet of backfill, exposed to water infiltration should be consisting of clayey material so that a relatively impervious condition is developed. Contractors should be informed that the use of heavy compaction equipment within close proximity to retaining walls could cause excessive wall movement and/or earth pressure in excess of design values. HU ASSOCIATES, INC. HA-4871-2 May 21, 2003 -19- Pavement Design of pavement structural sections is dependent on quality of the subgrade materials that cannot be determined until the finish of rough grading. Representative sample of the subgrade soil should be obtained in the proposed parking area at the time the subgrade is graded for R- Value testing in accordance with California Test Method 301. Based on the results of the preliminary soil investigation at the site, the typical soils that are anticipated in the subgrade will consist of sandy silt and silty sand. For preliminary design purposes, an R-value of 35 has been assumed for preliminary design of the pavement section. The actual R-value of the subgrade soil shall be tested and verified at the time of grading. An asphalt-concrete pavement section of 6 inches of asphalt concrete over 6 inches of crushed aggregate base may be used for preliminary design considerations for the proposed new street. Unless otherwise specified in the other sections of this report, subgrade soils within the proposed driveway area to a depth of 12 inches should be scarified, moistened or aerated as necessary, and compacted to at least 95 percent of the maximum density as determined by the ASTM D-1557-00 standard. The base material should be compacted to at least 95 percent. Observation and testing of all compaction shall be under the direction of the Soils Engineer. The Soils Engineer shall advise the owner and grading contractor immediately if any unsatisfactory soils related conditions exist and shall have the authority to reject the compacted fill ground until such time as corrective measures necessary are taken to comply with the specifications. Surface drainage should be provided for water collection and removal from road surfaces, and for interception and collection of water flowing from adjacent areas. HU ASSOCIATES, INC. HA-4871-2 -20- May21,2003 Excavation Excavation should be in accordance with all applicable requirements of the State of California Construction and General Industry Safety Order, the Occupational Safety and Health Act of 1970, the Construction Safety Act, and all other public agencies having jurisdiction. Construction specifications should clearly establish the responsibilities of the contractor for construction safety in accordance with CAL/OSHA requirements. No excavation shall be made during unfavorable weather. It is recommended that the excavated banks be entirely covered with plastic sheets when threatened by rains. When the excavation is interrupted by rain, operations shall not be resumed until the Soil Engineer indicates that conditions will permit satisfactory results. Post Grading Considerations Site Drainage The provision and maintenance of adequate site drainage and moisture protection of supporting soil is an important design consideration. Foundation recommendations presented herein assume proper site drainage will be established and maintained. To enhance future site performance, positive drainage devices such as sloping sidewalks, graded swales, and/or area drains should be provided around the building and in the rear yard pad to collect and direct all water away from the structure. Neither rain nor excess irrigation water should be allowed to collect or pond on the neither property nor flow towards the slope. Where slabs or pavement are not feasible adjacent to the buildings, the ground surface should be provided with a minimum gradient of about one percent away from the structures. All drainage should ultimately be directed to the street or other designated area. HU ASSOCIATES, INC. HA-4871-2 May 21, 2003 -21- Water should be transported off the site in approved drainage devices or unobstructed swales. Unpaved drainage swales should have a gradient of at least one percent. Swales or drainage paths through lawn areas should be provided with a gradient of at least one percent. Where necessary, drainage paths could be shortened by use of area drains and collector pipes. Planters adjacent to buildings should be avoided insofar as possible. Planting areas at grade should be provided with good positive drainage. Wherever possible, exposed soil areas should be above adjacent paved grades. Planters should not be depressed below adjacent paved grades unless provisions for drainage, such as catch basins and pipe drains are made. Adequate drainage gradient, devices and curbing should be provided to prevent runoff from adjacent pavement or walks into planting areas. Consideration should be given to irrigation methods that will promote uniformity of moisture in planters and beneath adjacent concrete "flat-work". Over-watering and under-watering of landscape areas must be avoided. All roof and wall surface drainage should be collected and conducted by a non-erosive device to the streets or to a designated area. Trench Backfill It is our opinion that utility trench and/or structural backfill consisting of the on-site material types could be best placed by mechanical compaction to a minimum of 90 percent of the laboratory maximum density. Density testing, along with probing, should be performed by the project soils engineer, or his representative, to verify proper compaction. If utility contractors indicate that it is undesirable to use compaction equipment in close proximity to a buried conduit, we would recommend the utilization of lightweight mechanical equipment and/or bedding of conduit with clean granular material prior to initiating mechanical compaction procedures. Other methods of utility trench compaction may also be appropriate as approved by the project geotechnical consultant at the time of construction. HU ASSOCIATES, INC. HA-4871-2 May 21,2003 -22- Where utility trenches are proposed parallel to building footings (interior and/or exterior trenches), the bottom of the trench should not extend below a 1 horizontal to 1 vertical plane project downward from the outside bottom edge of the adjacent footing. Where this condition occurs, the adjacent footing should be deepened. Slope Maintenance All proposed cut and fill slopes should be maintained a slope gradient no greater than 2 horizontal to 1 vertical. Landscape Plants In order to enhance surficial slope stability, the slope surface should be provided with deep-rooting vegetation requiring little watering. Plants native to the southern California area and plants relative to native plants are generally desirable. Irrigation Irrigation pipes should be anchored to slope faces, not placed in trenches excavated into slope faces. Slope irrigation should be minimized. If automatic timing devices are utilized or irrigation systems, provisions should be made for interrupting normal irrigation during periods of rainfall. Property owners should be made aware that over-watering of slope is detrimental to slope stability. Maintenance Periodic inspections of landscaped slope areas should be planned and appropriate measures should be taken to control weeds and enhance growth of the landscape plants. Some areas may require occasional replanting and/or reseeding. HU ASSOCIATES, INC. HA-4871-2 May 21,2003 -23- Property owners should be made aware that burrowing animals could be detrimental to slope stability. A preventative program should be established to control burrowing animals. Surface drains and downdrains should be periodically inspected and maintained free of debris. Damage to drainage improvements should be repaired immediately. Plan Review In order to prevent misinterpretation of this report by other consultants it is recommended that the Soils Engineer be provided the opportunity to review the final grading and foundation plans. The Soils Engineer will also determine whether any change in concept may have had any effect on the validity of the Soils Engineer's recommendations, and whether those recommendations have, in fact, been implemented in the design and specifications. If the Soils Engineer is not accorded the privilege of making this recommended review, he can assume no responsibility for misinterpretation or misapplication of his recommendations or for their validity in the event changes have been made in the original design concept without this prior review. Geotechnical Inspection All rough grading of the property must be performed under engineering supervision of the geotechnical consultants. Rough grading includes, but is not limited to, site preparation, cleaning, over-excavation, and fill placement. The geotechnical consultant should inspect all foundation excavations. Inspections should be made prior to installation of concrete forms and reinforcing steel to verify or modify, if necessary, conclusions and recommendations in this report. HU ASSOCIATES, INC. HA-4871-2 May 21,2003 -24- Inspections of the finish grading, utility or other trench backfill, retaining wall backfill, or other earthwork completed for the subject project should also be performed by the geotechnical consultant. If any of these inspections to verify site geotechnical conditions are not performed by the geotechnical consultant, liability for the safety and stability of the project is limited only to the actual portions of the project approved by the geotechnical consultant. It should be understood that the contractor shall supervise and direct the work and he shall be responsible for all construction means, methods, techniques, sequences and procedures. The contractor will be solely and completely responsible for conditions at the job site, including safety of all persons and property during the performance of the work. Periodic or continuous inspection by Hu Associates, Inc. is not intended to include verification of dimensions or review of the adequacy of the contractor's safety measures in, on or near the construction site. GRADING SPECIFICATIONS The following guidelines may be used in preparation of the grading plan and job specifications. 1) All site grading operations should conform to the local building and safety codes and to the rules and regulations of those governmental agencies having jurisdiction over the subject construction. 2) The grading contractor is responsible to notify governmental agencies, as required, and the Soils Engineer prior to initiating grading operations and any time grading is resumed after an interruption. 3) A diligent search for septic tanks, cesspools or underground lines should be performed during grading operations. Any abandoned water or oil wells encountered should be properly capped and treated in accordance with best-accepted practices. HU ASSOCIATES, INC. HA-4871-2 -25- May21,2003 4) Prior to receiving of new fill or where compacted fill is to provide support of structural loads, it is recommended that all loose or disturbed surface natural soils within the proposed construction areas be removed to underlying competent natural soil and replaced with properly compacted fill. The exposed bottom surfaces in each removal area should first be scarified to a depth of at least 8 inches, watered or air-dried as necessary to achieve near optimum moisture conditions, and than compacted in-place to at least 90 percent of the maximum laboratory density, 5) The on-site soils are suitable for use in compacted fills provided all trash, vegetation and other deleterious materials are removed prior to placement. 6) Where import materials are required for use on site, the Soils Engineer should be notified at least 48 hours in advance of importing in order to sample and test materials from proposed borrow sites. No import materials should be delivered for use on site without prior sampling and testing by the Soils Engineer. 7) All new fill shall consist of approved clean on-site or similar earth material, free of trash or debris, roots, vegetation or other deleterious material and shall be placed in thin horizontal lifts not exceeding 8 inches in loose thickness prior to compaction. Each lift should be watered or dried as needed, thoroughly blended to achieve near optimum moisture conditions then thoroughly compacted by mechanical methods. 8) No rock over 3 inches in greatest dimension shall be used in fill unless otherwise approved by the Soils Engineer. 9) No jetting or water tamping of fill soils shall be permitted. 10) No fill materials should be placed, spread or rolled during unfavorable weather conditions. When work is interrupted by heavy rains, fill operations should not be resumed until the field tests by the Soils Engineer indicate that the moisture content and density of the fill are as previously specified. HU ASSOCIATES, INC. HA-4871-2 May 21,2003 -26- 11) Unless otherwise specified, all other fills and backfills should be compacted to at least 90 percent of maximum laboratory density. 12) The compaction characteristics of all fill soils shall be determined by ASTM D-1557-00 standard. The field density and degree of compaction shall be determined by ASTM D- 1556, or by other ASTM standard methods that are acceptable to the governing public agency. 13) Observation and testing of all compaction shall be under the direction of the Soils Engineer. The Soils Engineer shall advise the owner and grading contractor immediately if any unsatisfactory soils related conditions exist and shall have the authority to reject the compacted fill ground until such time as corrective measures necessary are taken to comply with the specifications. 14) The Soils Engineer should be notified at least 2 days in advance of the start of grading. A joint meeting between a representative of the client, the contractor, and the Soils Engineer is recommended prior to grading to discuss specific procedures and scheduling. INVESTIGATION LIMITATIONS The conclusions and recommendations contained in this report are based on the data obtained from the test pits at the dates and locations indicated in the logs and the site plan. It is assumed that the soil conditions at the other areas do not deviate significantly from those disclosed in the test pits. If any variations or undesirable conditions are encountered during construction, this office should be notified so as to consider the need for modifications. HU ASSOCIATES, INC. HA-4871-2 May 21,2003 -27- No responsibility for construction compliance with the design concepts, specifications, or recommendations is assumed unless an on-site review by a representative of this office is performed during the course of construction that pertains to the specific areas covered by the recommendations contained herein. The report has been compiled for the exclusive use of A & A Development or its authorized representatives. It shall not be transferred to or used by a third party, to another project, or applied to any other project on this site, other than as described herein, without the consent and/or thorough review of this office. The findings of this report are valid as of the present date. However, changes in the conditions of the property can occur with the passage of time, whether they are due to natural processes or to the works of man, on this or adjacent properties. In addition, changes in applicable or appropriate standards may occur, whether they result from legislation or the broadening of knowledge. Accordingly, the findings of this report may be invalidated, wholly or partially, by changes outside of our control. Therefore, this report is subject to review and should not be relied upon after a period of one year without such a review. Final approval of plans and reports by all consultants, and issuance of any building and grading permits, rests with the controlling agencies. As the circumstances that control the decision process are clearly beyond the control of this facility, we cannot assume any responsibility for the success of obtaining proper authorizations, nor for the costs involved. This report is issued with the understanding that it is the responsibility of the owner, or the proper representative thereof, to insure that the information and recommendations contained herein are called to the attention of all parties interested in the project and that the necessary steps are taken to see that the contractors and subcontractors carry out such recommendations in the field. HU ASSOCIATES, INC. HA-4871-2 May 21,2003 -28- All exploratory pits used for subsurface exploration were backfilled with reasonable effort to restore the areas to their original condition. As with any backfill, some consolidation and subsidence of the backfill soils may result in time, causing some depression of the pit area and possibly a potentially hazardous condition. The client and/or owner of the property are advised to periodically examine the pit areas, and if necessary, backfill any resulting depressions. Hu Associates, Inc. shall not be liable for any resulting injury or damage. The report is subject to review by controlling public agencies having jurisdiction. Respectfully submitted, HU ASSOCIATES, INC Chenlun Lee RCE 64661 Expiration Date 6-30-03 Hu, Ph.D. RCE 29^, RGE 2240 Expiration date 3-31-07 CL/HJ/REH/ps .rfp- >Hank Jong, P RG, CEG 1646 Expiration Date 11 -30-04 HU ASSOCIATES, INC. VICINITY MAP . ,Proposed Single-Family Residence 3002 Highland Drive Carlsbad, California HU ASSOCIATES, INC. Geotechnical Engineering Consultants PROJECT No. HA-4871-2 PLATE "7—-. 1 CQNC DENSE TREES 1 •'> PROPOSED'' ; /DENSE/TREESr WALL • ' •- ' /' / PROPOSE!) 7V / r/ --TO BE'DEMOLISHED •;—r —.•=uu»fj 7PAD; 7 £17 ,.«-3i . \ t=9tt5'l Testa* PfiD j!7J.f ! 10,136 SO. FT!.' I GROSS & NET i 1,1. ,~L.'! i .!. L-|_;_^ ^ n/j i _ .. . ;•• \$ f:; ; i EJENSE /TREES , '' E.S.V.C.P. CONC ENCASED 30' £t-»tr-i t*J•X CO 3 S•~a f . DENSE': TRE/sligep/ ^-s -• •/ ' ^J. ' '^gl^gjE^:! "rriz^F^'^^ . ". - by Melchior Land Surveying, Inc., dated 4/1 1/03. SITE PLAN AND GEOLOGIC MAP HU ASSOCIATES, INC. Geotechnical /Environmental Engineering Consultants DATE 1" = 60' 5/16/03 PROJECT NO. PLATE HA-4871-2 Sindslonp, undivided Torrey and Drlmar nawl* in La Jollc quadrangle and vnnamea uittlr to north; a irn iitrlnJc* .«nm<- Rose Canvonihale for ihart distance north of Ln Jitltu auadiangU; EconomicSignificance: tovrct of pln and *f>rciatiy tanda. ntriiaive daciu- (T^i and latiu (Tvt) \\wAnQtUS^ ffe^^^.-&^li^ENCI \^&ir^^m&mj^rn^ Crinilir rocki. undivided vcrtr diarilt (lonalilcl, trilh minor granodiorite, and granite; Economic Siynifirancr: xourrc of dimension s,ione, decomposed ffranilt, and crus^rd and broken stone; conjoin depotlis of oold, tunytlcn, prm vunerals, feldspar, quarts, and molybdenum. l intrusive rocks usoctated with the metivolcinic rociu Groni'U to granodiaritt porphyry and rhyolite to daciU. Reference: "Geology and Mineral Resources of San Diego County, California" by F. H. Weber. REGIONAL GEOLOGIC MAP Proposed Single-Family Residences 3002 Highland Drive Carlsbad, California HU ASSOCIATES, INC. Geotechnical Engineering Consultants PROJECT No. HA-4871-2 PLATE 2a r r m « ,v I 1II ffl » y SECTION A-A1 SCALE: 1"=20 200n PAD2 1801 oIy UJ 160 140J B SECTION B-B1 SCALE: 1"=201 B' 200n UJ180-u. iLU 140J PAD4 Proposed House Proposed Grade PADS PAD6 GEOLOGIC SECTION HU ASSOCIATES, INC Geotechnical /Environmental Engineering Consultants SCALE DATE 1" = 20' 5/21/2003 PROJECT NO. PLATE HA-4871-6 i i i i i i i i i 1 I C/! O2 On 1 ao CiOJo 1.j-a n° ~ a3 <Kl3' 1.3 at^c 0aE? '"d 73 ^ H Q 1 CO ~J I tO r HW * OmO O Q 0 (/)moH oz •0 o oVIn w CD H g a tO M- tT h^ IQw rr i-jD- (h CD0- i n ^ ft>OJ 3QJ L^r_j P *"*• i-h Q ^ 2 "•-I (flP. <! H- 0) it1 3nn> 01 SECTION C-C1 c SCALE: 1"=20' c- 200-1 ^a 180- LL. i 0 ^UJH 160-ni iw 140- PAD7 Existing /f [\ Proposed Grade \ \ Grade/ Proposed / / House / / /PL/ II_l_ ^ | [ / SSVN^ / TP2 ^\ Natural Soil , • Sandstone Tes UNSUITABLE EARTH MATERIAL • LIMITS OF FINAL EXCAVATION FINAL NATURAL SLOPE TOE OF SLOPE SHOWN ON GRADING PLAN COMPETENT EARTH MATERIAL MINIMUM DOWNSLOPE KEY DEPTH 1.5 times the equipment width PROVIDE BACKDRAIN AS REQUIRED PER RECOMMENDATIONS OF SOILS ENGINEER DURING GRADING WHERE NATURAL SLOPE GRADIENT IS 5:1 OR LESS, BENCHING IS NOT TO BE PLACED ON COMPRESSIBLE OR UNSUITABLE MATERIAL. FILL SLOPE ABOVE HU ASSOCIATES, INC. NATURAL GROUND DETAIL Geotechnical Engineering Consultants Proposed Single -Family Residences 3002 Highland Drive Carlsbad, California PROJECT No. HA-4871-2 PLATE 5 FINISH SURFACE SLOPE 4" MINIMUM DIAMETER SOLID OUTLET PIPE SPACED PER SOIL ENGINEER REQUIREMENTS DURING GRADING 2% MINIMUM GRADIENT A 3 FT3 MINIMUM PER LINEAL FOOT APPROVED FILTER ROCK* 4" MINIMUM APPROVED PERFORATED PIPE" (PERFORATIONS DOWN) MINIMUM 2% GRADIENT TO OUTLET BENCH INCLINED TOWARD DRAIN TYPICAL BENCHING DETAIL A-A' 12" MINIMUM •APPROVED PIPE TYPE SCHEDULE 40 POLYVINYL CHLORIDE (P. V. C.) OR APPROVED EQUAL. MINIMUM CRUSH STRENFTH 1000 PSI • TEMPORARY FILL LEVEL / 12" MINIMUM COVER \ \ / COMPACTED BACKFILL / ^/C ) 4" MINIMUM DIAM SOLID OUTLET PI 'FILTER ROCK TO SPECIFICATIONS OR APPROVED EQUAL: PERCENTAGE PASSING 100 90-100 40-100 25-40 5-15 0-7 0-3 TYPICAL BACKDRAIN DETAIL Proposed Single-Family Residences 3002 Highland Drive Carlsbad, California HU ASSOCIATES, INC. Geotechnical Engineering Consultants PROJECT NO. HA-4871-2 PLATE HA-4871-2 May 21, 2003 APPENDIX FIELD EXPLORATION AND LABORATORY TESTING FIELD EXPLORATIONS The subsurface conditions at the site were explored by excavating six test pits at the locations shown on the Plot Plan, Plate 2, adopted from "Grading Plan" prepared by Melchior Land Surveying, Inc., dated April 11, 2003. The test pits were excavated by means of the backhoe to a depth of 10 feet below the existing ground surface. The approximate locations of the test pits were determined by tape measurements from the property boundaries and existing facilities. Approximate elevation of the test pits was determined by extrapolation between plan contours: The location and elevation of the test pits should be considered accurate only to the degree implied by the method used. The soils encountered during excavation were logged by the field engineer. The soils are classified in accordance with the Unified Soil Classification System described on Plate A-1. Undisturbed samples of soils were extracted at selected intervals from the test pits in a barrel sampler with tapered cutting shoe. The undisturbed soil retained in 2.5-inch diameter by one- inch rings within the sampler were secured in moisture resistant bags and plastic sample cans as soon as taken to minimize the loss of field moisture while being transported to the laboratory for testing. The relative sampler penetration resistance exhibited by the soil types encountered is tabulated in the Blow per Foot column of the Log of Test Pit. Detailed logs of test pits are presented on Plates A-2 through A-4, Log of Test Pit. The lines designating the interface between soil materials on the logs of test pit represent approximate boundaries. The transition between materials may be gradual. HA-4871-2 May 21, 2003 LABORATORY TESTING -2a- Moisture-Density The field moisture content and dry density of the materials encountered were determined by performing tests on selected undisturbed samples to aid in the classification and correlation of the soil and to obtain qualitative information relative to their strengths and compressibility. The results of the tests are shown on the Log of Test Pit, Plates A-2 through A-4. Direct Shear Tests Direct shear tests were performed on selected undisturbed onsite samples to evaluate shear strength and supporting capacity of the foundation materials. Shear tests were made with a direct shear machine of the displacement control type at a displacement rate of approximately 0.005 inches per minute. The samples were soaked in water for at least 24 hours to approximately saturated moisture condition and then sheared under various normal stresses. The ultimate shear strength values determined from the tests are presented on Plates A-5 and A-6, Direct Shear Test. Consolidation Tests Consolidation tests were performed on representative undisturbed samples of the natural soils to evaluate the volume changes of soil subjected to increased loads. Deformations of the specimen are recorded at selected intervals. The results of pressure consolidation curves, which are used to estimate the probable magnitude and rate of settlement of the tested soil under applied loads, are presented on Plates A-7 through A-9, Consolidation Test. HA-4871-2 May 21,2003 Expansion Tests -3a- Expansion tests were performed on representative samples of the on-site materials in accordance with the Uniform Building Code Standard No. 18-1 to evaluate its volume change with moisture. The results are as follows: Sample B-3 @ 2' Classification SAND, fine to medium, clayey, silty Expansion Index 20 Expansion Potential low MAJOR DIVISIONS GROUP SYMBOLS TYPICAL NAMES COARSE GRAINED SOILS (More than 50% of material is LARGER than No. 200 sieve size) GRAVELS (More than 50% of coarse fraction is LARGER than No. 4 sieve size) SANDS (More than 50% of coarse fraction is SMALLER than No. 4 sieve size) CLEAN GRAVELS (Little or no fines) GW Well graded gravels and gravel - sand mixtures, ittle or no fines 'oorly graded gravels and gravel - sand mixtures, ittle or no fines GRAVELS WITH FINES (Appreciable Amount of fines) CLEAN SANDS {Little or no fines) Silty gravels, gravel - sand - silt mixtures GC Clayey gravels, gravel - sand - clay mixtures sw Well graded sands and gravelly sands, little or no fines SP 'oorly graded sands and gravelly sands, little or no fines SM Silty sands, sand-silt mixtures SANDS WITH FINES (Appreciable Amount of fines) sc Clayey sands, sand - clay mixtures FINE GRAINED SOILS (More than 50% of material is SMALLER than No. 200 sieve size) SILTS AND CLAYS (Liquid limit LESS than 50) norganic silts and very fine sands, rock flour, silty or clayey fine sands or clayey silts with slight plasticrty CL norganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays, lean clays SILTS AND CLAYS (Liquid limit GREATER than 50) OL Organic silts and organic silty clays of low plasticity MH Inorganic silts, micaceous or diatomaceous fine sands or silts, elastic silts CH Inorganic clays of high plasticily, fat clays OH Organic clays of medium to high plasticity, organic silts HIGHLY ORGANIC SOILS Pt Peat, muck and other highly organic soils BOUNDARY CLASSIFICATIONS Soils possessing characteristics of two groups are designated by combinations of group symbols. Reference: The Unified Soil Classification System, Corps of Engineers, U. S. Army Technical Memorandum No. 3-357, Vol1, March, 1953 (Revised April, 1960) UNIFIED SOIL CLASSIFICATION SYSTEM Proposed Single-Family Residences 3002 Highland Drive Carlsbad, California HU ASSOCIATES, INC. Geotechnical Engineering Consultants PROJECT No. HA-4871-2 PLATE A-l NOTE: The data presented on this log is simplification of actual subsurface conditions encountered and applied only at the location of this pit and the date of excavation. It is not warranted to be representative of subsurface conditions at other locations and times. c IS 0 5 10 a. 7 20 26 21 1Field MoistureV, of Dry Weight6.1 10.3 8.6 9.2 IDry Densitylbs./cu.ft.110.3 115.4 116.6 117.6 1Shear Resistancekips/sq.ft.1Confining Pressurekips/sq.ft.u Sta(Q U 'c3 SM £ I TEST PIT NO. £ •111 SAND fine to medium, silty fine to medium, slightly clayey ||| ill SANDSTONE medium grain, silty, slightly clayey 1 Elevation: 176' brown dark brown dark yellow brown End of Test Pit @ 10' TEST PIT NO. slightly moist moist m dense dense 2 Elevation: 162' 0 - 5 M 10 6 17 27 26 6.6 9.3 10.0 8.0 101.7 112.9 112.1 108.5 SM ^HSAND fine to medium, silty •H fine to medium, silty, slightly clayey 1 1 SANDSTONE medium grain, silty | brown dark brown dark yellow brown End of Test Pit @ 10' Date Excavated: 4/30/03 Equipment: backhoe Driving Weight: 1 40 Ibs @ 30-inch drop Water Depth: not encountered slightly moist moist m dense to dense dense Proposed Single-Family Residences LOG OF TEST PIT 3002 Highland Drive Carlsbad, California HU ASSOCIATES, INC. Geotechnical Engineering Consultants PROJECT No. HA- 4 87 1-2 PLATE A- 2 NOTE: The data presented on this log is simplification of actual subsurface conditions encountered and applied only at the location of this pit and the date of excavation. It is not warranted to be representative of subsurface conditions at other locations and times. 1a.c .0 - 5 - 10 Blow per Foot8 31 39 64 Field Moisture% of Dry Weigh12.1 13.2 12.5 9.2 Dry Densitylbs./cu.ft.104.5 114.4 112.8 125.8 0)Shear Resistanckips/sq.ft.£Confining Pressukips/sq.ft.o Unified ClassiflcatSM 1 Soil SymbolTEST PIT NO. 3 Elevation: 154' IIIJSAND fine to medium sandy, silty, clayey •I SANDSTONE medium grain , silty, slightly clayey fine to medium grain, silty gray brown reddish brown dark yellow brown moist m dense to dense dense very dense End of Test Pit @ 10' TEST PIT NO.4 Elevation: 160' 0 5 10 3 22 26 28 8.5 8.9 9.4 7.5 109.5 114.2 110.3 113.0 SM SAND fine to medium, silty fine to medium, slightly clayey SANDSTONE medium grain, silty, slightly clayey It gray brown dark brown dark yellow brown slightly moist to moist m dense dense End of Test Pit @ 10' Date Excavated: 4/30/03 Equipment: backhoe Driving Weight: 140 lbs@ 3 0-inch drop Water Depth: not encountered LOG OF TEST PIT HU ASSOCIATES, INC. Geotechnical Engineering Consultants Proposed Single-Family Residences 3002 Highland Drive Carlsbad, California PROJECT No. HA-4871-2 PLATE A- 3 NOTE: The data presented on this log is simplification of actual subsurface conditions encountered and applied only at the location of this pit and the date of excavation. It is not warranted to be representative of subsurface conditions at other locations and times.Depth in Feet0 5 10 I 5 2 17 20 30 "ield Moistureof Dry Weight8.6 7.6 9.7 9.3 >» "* Q ~ 94.2 119.2 114.5 114.8 0)Oe a !20) O nfining Pressurekips/sq.ft.3 cg '« O 'E3 SM Soil SymbolTEST PIT NO.5 Elevation: 175' SAND very fine to medium, silty fine to medium, silty, slightly clayey SANDSTONE medium-grained , silty, slightly clayey brown dark brown dark yellow brown slightly moist to moist medium dense dense End of Test Pit @ 10' TEST PIT NO.6 Elevation: 170' 0 5 10 3 20 20 20 6.5 5.1 5.9 8.2 106.4 114.6 114.0 114.6 SM SAND fine to medium, silty fine to medium, silty, slightly clayey SANDSTONE medium grain, silty, slightly clayey brown It gray brown dark yellow brown slightly moist moist medium dense dense End of Test Pit @ 10' Date Excavated: 4/30/03 Equipment: backhoe Driving Weight: 140 Ibs @ 30-inch drop Water Depth: not encountered LOG OF TEST PIT HU ASSOCIATES, INC. Geotechnical Engineering Consultants Proposed Single-Family Residences 3002 Highland Drive Carlsbad, California PROJECT No. HA-4871-2 PLATE A- 4 § 5.0 4.5 4.0 cr (Ai_0)a tna.'2 3.5 3.0 u I«2'55 2.5 2.0 O) 1.5c CO Oi C 1.0 0.5 0.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 Normal Pressure - kips per square foot 4.5 5.0 Natural Soil: Samples were tested under saturated and drained conditions. Test Pit No. Depth (feet)UC Initial Water Content (% of dry wt.) Final Water Content (% of dry wt.) Dry Density (Ibs / cu.ft.) Cohesion (Ibs / sq. ft.) Angle of Friction (degrees) 9.3 5.1 18.2 17.6 112.9 114.6 320 230 35 36 DIRECT SHEAR TEST DATA Proposed Single-Family Residences 3002 Highland Drive Carlsbad, California HU ASSOCIATES, INC. Geotechnical Engineering Consultants PROJECT No. HA-4871-2 PLATE A-5 O £ £CB Cfl C. (0 5.0 4.5 4.0 3.5 3.0 2.5 2.0 0>Ocm .2 0)£ O) = 1.5 re 1.0 0.5 0.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 Normal Pressure - kips per square foot 4.5 5.0 Bedrock: Samples were tested under saturated and drained conditions. Test Pit No. Depth (feet)UC Initial Water Content (% of dry wt.) Final Water Content (% of dry wt.) Dry Density (Ibs / cu.ft.) 9.7 17.7 114.5 Cohesion (Ibs/sq.ft.) 360 Angle of Friction (degrees) 34 DIRECT SHEAR TEST DATA Proposed Single-Family Residences 3002 Highland Drive Carlsbad, California HU ASSOCIATES, INC. Geotechnical Engineering Consultants PROJECT No. HA- 4 8 71 - 2 PLATE A-6 Norma Load - kips per square foot 0.1 0.2 0.3 1 2345 10 0 1 2 3 C 4 O +•» 03 2 5 0 tfl C 0 6 O •*- C <» 7 Oi_ 0) 0. 8 9 10 11 12 •• » •*. "»«. ••» *^ •». •"i -^ SS \ " *— VS •• — \ • • \ "— \ MM s — 1 \ ™ •i •• 20 30 sA Test Pit No. 1 @ 4.0' O Water Permitted to Contact Sample CONSOLIDATION TEST HU ASSOCIATES, INC. Geotechnical Engineering Consultants Proposed Single-Family Residences 3002 Highland Drive Carlsbad, California PROJECT No. HA-4871-2 PLATE A- 7 Normal Load - kips per square foot 0.1 0.2 0.3 1 2345 10 0 1 2 3 C 4 0 4-tre 2 5 O<n c 0 6 O +- C 0) 7 O^ 0) 0. 8 9 10 11 12 «•• •*• **» —» -* *•• •*« •^ ^N ^« ""•^-jr*. ^ ^' — \ •»» . \ «MMI s — . \ t^m» \ •IHI s ••i s ^ 20 30 s Test Pit No. 3 @ 4.0' O Water Permitted to Contact Sample CONSOLIDATION TEST HU ASSOCIATES, INC. Geotechnical Engineering Consultants Proposed Single -Family Residences 3002 Highland Drive Carlsbad, California PROJECT No. HA 4871-2 PLATE A- 8 Normal Load - kips per square foot 0.1 0.2 0.3 1 2345 10 0 1 2 3 C 4o 4-» 03 2 5 Oto C 0 6 O C (» 7 Ok. OJ Q. S 9 10 11 12 •* ^< •*•• S» •*» •^ **l "•* ••. A -• — — \> «— • \ •~~ \ iHH \ 1MB S •• \ • • 20 30 ^.i Test Pit No. 4 @ 4.0' 0 Water Permitted to Contact Sample CONSOLIDATION TEST HU ASSOCIATES, INC. Geotechnical Engineering Consultants Proposed Single-Family Residences 3002 Highland Drive Carlsbad, California PROJECT No. HA-4871-2 PLATE A- 9