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HomeMy WebLinkAboutCT 04-10A; Poinsettia Place; Geotechnical; 2004-04-13RECEIVED MAY 1 1 230^ CITY OF CARLSBAD PLANNING DEPT. GEOTECHNICAL EVALUATION FOR PROPOSED RESIDENTIAL BUILDING SRWB PROPERTY SOUTH SIDE OF CASSIA ROAD, EAST OF POINSETTIA LANE CARLSBAD, CALIFORNIA PREPARED FOR BARRATT AMERICAN, INC. 5950 PRIESTLY DRIVE CARLSBAD, CALIFORNIA 92008 PREPARED BY GEOTEK, INC. 1384 POINSETTIA AVENUE VISTA, CALIFORNIA 92081 PROJECT No.: 2555-SD3 APRIL 13,2004 Ik 1384 Poinsettia Ave., Suite A, Vista, CA 92081-8505 (760) 599-0509 FAX (760) 599-0593 I ,NC. Geotechnical Environmental Materials April 13, 2004 Project No.: 2555-SD3 Barratt American, Inc. 5950 Priestly Drive Carlsbad, Califomia 92008 Attention: Mr. Dave Jacinto Subject: Geotechnical Evaluation Proposed Residential Buildings SRWB Property South Side of Cassia Road, East of Poinsettia Lane Carlsbad, Califomia Dear Mr. Jacinto: As requested and authorized, GeoTek, Inc. (GeoTek) has perfonned a geotechnical evaluation for the subject parcel located along the south side of Cassia Road, Carlsbad, Califomia. This report presents the results of our evaluation, discussion of our findings, and provides geotechnical recommendations for foundation design and construction. In our opinion, the proposed development of the site appears feasible fi-om a geotechnical viewpoint provided that the recommendations included herein are incorporated into the design and construction phases of the project. The opportunity to be of service is sincerely appreciated. If you should have any questions, please do not hesitate to call our office. Respectfiilly submittej GeoTek, Inc. effrey P. Blake, CEG 2248, Exp. 10/: Project Manager (5) Addressee Todd C. Schmitz, Project Geologist Sirrion I. S^iid, GE 2641, Exp. 9/30/05 Senior Engineer G:\Projects\Projects 2000 to 2999\ProJects 2550 to 2599\2555 Barratt_SRWBProperty\Existingpadgeo'rpt.doc ARIZONA CALIFORNIA NEVADA BARRATT AMERICAN, INC. Project No.: 2555-SD3 Geotechnical Evaluation April 13, 2004 Proposed Residential Building Page i TABLE OF CONTENTS 1. INTENT 1 2. PURPOSE AND SCOPE OF SERVICES 1 3. SITE DESCRIPTION AND PROPOSED DEVELOPMENT 2 3.1 SITE DESCRIPTION 2 3.2 PROPOSED DEVELOPMENT 2 3.3 PREVIOUS STUDIES 2 4. FIELD EXPLORATION AND LABORATORY TESTING 3 4.1 FIELD EXPLORATION 3 4.2 LABORATORY TESTING 3 5. GEOLOGIC AND SOILS CONDITIONS 3 5.1 GENERAL 3 5.7.7 Fill 4 5. J.2 Alluvium 4 5.1.3 Santiago Formation 4 5.2 SURFACE AND GROUNDWATER 4 5.3 FAULTING AND SEISMICITY 5 5.4 OTHER SEISMIC HAZARDS 5 6. CONCLUSIONS AND RECOMMENDATIONS 6 6.1 GENERAL 6 6.2 EARTHWORK CONSIDERATIONS 6 6.2.7 Site Clearing 6 6.2.2 Fills 6 6.2.3 Remedial Grading 6 6.2.4 Excavation Cliaracteristics 7 6.3 DESIGN RECOMMENDATIONS 7 5.5.7 Foundation Design Criteria 7 6.3.2 Seismic Design Parameters 8 6.3.3 Foundation Set Baclis p 6.3.4 Slab-on-Grade Construction p 6.3.5 Subgrade Moisture P 6.3.6 Soil Corrosivity 10 6.3.7 Pavement Design 10 6.4 SITE DRAINAGE 10 6.5 RETAINING WALL DESIGN AND CONSTRUCTION 11 6.5.1 General Design Criteria 77 65.2 Wall Backfill and Drainage 7 7 6.6 PLAN REVIEW AND CONSTRUCTION OBSERVATIONS 12 7. LIMITATIONS 13 8. SELECTED REFERENCES 14 BARRATT AMERICAN, INC. Project No.: 2555-SD3 Geotechnical Evaluation April 13, 2004 Proposed Residential Building Page ii TABLE OF CONTENTS ENCLOSURES Figure 1 - Site Location Map Figure 2 - Geotechnical Map Figure 3 - Generalized Geologic Cross-Section Figure 4 - Generalized Geologic Cross-Section Appendix A - Logs of Exploratory Borings Appendix B - Results of Laboratory Testing Appendix C - General Grading Guidelines BARRATT AMERICAN, INC. Project No.: 2555-SD3 Geotechnical Evaluation April 13, 2004 Proposed Residential Building Page 1 1. INTENT It is the intent of this report to aid in the design and constmction of the proposed development. Implementation of the advice presented in Section 6 of this report is intended to reduce risk associated with constmction projects. The professional opinions and geotechnical advice contained in this report are not intended to imply total performance of the project or guarantee that unusual or variable conditions will not be discovered during or after constmction. The scope of our evaluation is limited to the northem portion of the site, which is shown on Figure 2. This evaluation does not and should in no way be constmed to encompass any areas beyond the specific area of the proposed constmction as indicated to us by the chent. Further, no evaluation of any existing site improvements is included. The scope is based on our understanding of the project and the client's needs, and geotechnical engineering standards normally used on similar projects in this region. 2. PURPOSE AND SCOPE OF SERVICES The purpose of this study was to evaluate the overall geotechnical conditions on the site. Services provided for this study included the following: > Research and review of available published data regarding geologic and soil conditions at the site including previous site-specific geotechnical investigations. > Site exploration consisting of the excavation, logging, and sampling of 8 exploratory borings. > Laboratory testing on representative samples collected during the field investigation. > Review and evaluation of site seismicity, and > Compilation of this geotechnical report which presents our findings, conclusions, and recommendations for site development. BARRATT AMERICAN, INC. Project No.: 2555-SD3 Geotechnical Evaluation April 13, 2004 Proposed Residential Building Page 2 3. SITE DESCRIPTION AND PROPOSED DEVELOPMENT 3.1 SITE DESCRIPTION The subject property, known as SRWB Property, is located along the south side of Cassia Road, and east of Poinsettia Lane in the City of Carlsbad, Califomia. Based on our review of the most recent available information (Geocon Inc., 1999), the subject site was graded in the late 90's with a partial removal of alluvial soils followed by the placement of compacted fill soils. An approximately 20-foot high fill slope is located along the westem portion of the site. The property is bounded to the north and west by residential housing and to the east and south by undeveloped property. The current topography of the proposed project area slopes slightly to the west and soutii. The southem portion of the overall property consists of an undeveloped ridge and was not evaluated as a part of this study. Existing site elevations in the proposed study area range from 270 feet above Mean Sea Level (MSL) at the northeast comer to 215 feet above MSL at the westem side of the project site. The site is covered with small vegetative growth. Further information regarding site layout is shown on Figure 2. 3.2 PROPOSED DEVELOPMENT Based on the information available to us, it is our understanding that the proposed multi-unit residential buildings will consist of one to three-story wood frame stmctures. Other related site improvements such as parking and drive areas, along with a subterranean parking stmcture, are also plaimed. It is assumed that the building foundations will consist of spread and continuous wall footings founded at or near fmish grade elevations. It is estimated that additional fill that ranges up to 12 feet will be needed to achieve proposed finish grades. The proposed extension of Poinsettia Lane will require additional fill of up to 30 feet in thickness. 3.3 PREVIOUS STUDIES The most recent study of this project area was performed by Geocon Inc., in 1999. The text portion of this report was available for review. Test data, boring logs, and the site plan were not available for review. The original geotechnical investigation for the project area was performed in 1996 by Geotechnical Exploration Inc. (GEI) Additional site work was BARRATT AMERICAN, INC. Project No.: 2555-SD3 Geotechmcal Evaluation April 13, 2004 Proposed Residential Building Page 3 conducted in 1997 by Pacific Soils Engineering, Lie. (PSEI) as a part ofthe Poinsettia Hill development on the north side of Cassia Street. Based on our review of the above reports, the existing fill materials appear to have been placed as engineered fill. The alluvium materials were partially removed and recompacted. The alluvium left in place was considered suitable based on in-situ field testing. 4. FIELD EXPLORATION AND LABORATORY TESTING 4.1 FIELD EXPLORATION The field exploration was performed on March 11, 2004. Eight (8) exploratory borings were excavated with a tmck mounted CME 75 to a maximum depth of 41.5 feet. The borings were located as shown on Figure 2, Boring Location Plan. A geologist from our firm logged the borings and collected samples for use in laboratory testing. The logs of exploratory borings and additional information regarding field sampling and testing procedures are included in Appendix A. The area of the proposed Poinsettia Lane extension was not investigated due to site constraints. 4.2 LABORATORY TESTING Laboratory testing was performed on selected disturbed and relatively undistiirbed samples collected during the field investigations. The purpose of the laboratory testing was to confirm the field classification of the soil materials encountered and to evaluate their physical properties for use in the engineering design and analysis. The results ofthe laboratory testing program along with a brief description and relevant information regarding testing procedures are included in Appendix B. 5. GEOLOGIC AND SOILS CONDITIONS 5.1 GENERAL A brief description of the earth materials encountered is presented in the following sections. A more detailed description of these materials is provided on the exploratory boring logs BARRATT AMERICAN, INC. Project No.: 2555-SD3 Geotechnical Evaluation April 13, 2004 Proposed Residential Building p^gg 4 included in Appendix A. Based on our site reconnaissance, subsurface excavations, and review of existing data, the site is underlain to the depth explored by the Santiago Formation. Alluvium is found overlying the formational material. A layer of engineered fill materials mantles the study area. 5.1.1 Fill A layer of documented fill materials ranging up to 38-feet in thickness mantles the site. The fill is generally tan to light-brown, moist, clayey fine sand to sandy clay. Based on the results of field and laboratory testing, the fill generally possesses a relative compaction varying between 85 to 96 percent of maximum density in accordance with ASTM D1557. The fill appears to be an engineered fill placed during past grading operations on this site (PSEI, 1998). The Expansion Index (EI) for these materials was found to have a low to medium expansion potential (EI<91). 5.1.2 Alluvium As encountered, the alluvium consists of light gray to dark-brown, clayey sands and interbedded silty sands. The results of our field testing show the alluvium to be medium dense to dense with an average N-value over 20 blows per foot. 5.1.3 Santiago Formation According to published geologic maps (CDMG, Open File Report 96-02) the site is underiain by tiie Tertiary-aged Santiago Fonnation. These sedimentary materials were encountered to the maximum depth explored of 41.5 feet and typically consist of pooriy indurated and slightiy cemented sandstone that breaks into yellow-brown and gray, dense, moist, silty fine sand. 5.2 SURFACE AND GROUNDWATER No surface water or ponding was observed at time of the field study. Site drainage should be reviewed and designed by the project civil engineer. Groundwater was not encountered in our exploratory excavations. No natural groundwater condition is known to be present which would impact site development. However, groundwater or localized seepage can occur due to variations in rainfall, irrigation practices, and other factors not evident at the time of this investigation. BARRATT AMERICAN, INC. Project No.: 2555-SD3 Geotechnical Evaluation April 13, 2004 Proposed Residential Building Page 5 5.3 FAULTING AND SEISMICITY The site is in a seismically active region. No active or potentially active fault is known to exist at this site. The site is not situated within an Alquist-Priolo Earthquake Fault Zone (Special Studies Zone). The computer program EQFAULT (Blake, 2000a) was used to determine the distance to known faults and estimate peak ground accelerations based on a deterministic analysis. The Rose Canyon Fault located approximately 6.2 miles from the site is considered to represent the highest risk to generate ground shaking. A maximvun earthquake magnitude of 6.9 and an estimated peak site acceleration of 0.391 g are postulated based on the analysis. 5.4 OTHER SEISMIC HAZARDS The liquefaction potential on this site is considered to be low due to the dense and clayey nature ofthe subsurface soils and lack ofa shallow water table. The dynamic settlement due to liquefaction or soil densification can be considered negligible. The potential for secondary seismic hazards such as seiche and tsunami is considered to be negligible due site elevation and distance from an open body of water. BARRATT AMERICAN, INC. Project No.: 2555-SD3 Geotechnical Evaluation April 13, 2004 Proposed Residential Building Page 6 6. CONCLUSIONS AND RECOMMENDATIONS 6.1 GENERAL Proposed development of the site appears feasible from a geotechnical viewpoint provided the following recommendations are incorporated into the design and constraction phases of development. 6.2 EARTHWORK CONSIDERATIONS Earthwork and grading should be perfonned in accordance with the applicable grading ordinances of the City of Carlsbad and our recommendations contained in this report. 6.2.1 Site Clearing In areas of planned grading or improvements, the site should be cleared of vegetation, roots and properly disposed of offsite. 6.2.2 Fills The onsite soils may be used in the fill or imdercut areas. Any import fill should consist of low expansive soils (EK51) and evaluated by our firm prior to arrival at the site. The fill materials should be compacted in layers no thicker than 8 inches to at least 90 percent of maximum dry density at near optimum moisture content, as determined in accordance with ASTM Test Method D1557-00. The bottom of excavations should be scarified to a depth of 8 inches; moisture conditioned, and recompacted to at least 90 percent of maximum dry density. 6.2.3 Remedial Grading We recommend that the top 2 to 3 feet ofthe surficial materials within the building footprint areas or beneath any settiement sensitive stractures including building floor slabs and exterior flatwork/sidewalks be removed and recompacted in accordance with Section 6.2.2 above. The bottom of removal should be scarified and moisture conditioned to a minimum of 2.0 percent above optimum moisture content, and recompacted to at least 90 percent of maximum dry density. The detention basin may require fiirther remediation based on BARRATT AMERICAN, INC. Project No.: 2555-SD3 Geotechnical Evaluation April 13, 2004 Proposed Residential Building Page 7 moisture content of fill materials to be determined at the time of grading. The proposed Poinsettia Lane extension area may require additional removals to be determined at the time of grading. Removals of up to 3 feet of surficial alluvium should be anticipated while deeper removals may be possible. Alluvium left in place should meet a minimum dry density of 105 pcf or relative compaction of at least 85 percent of maximum dry density in accordance with ASTM test procedure Dl557.00. 6.2.4 Excavation Characteristics Excavation in the onsite soils within the depth explored is expected to be easy using heavy- duty grading equipment. All temporary excavations for grading purposes and installation of underground utilities should be constmcted in accordance with OSHA guidelines. Temporary excavations within the onsite formational materials should be stable at 1:1 inclinations for cuts less than 10 feet in height. 6.3 DESIGN RECOMMENDATIONS 6.3.1 Foundation Design Criteria Foundation design criteria for conventional foundation system in conformance with the 1997 UBC are presented herein. These are typical design criteria for the proposed foundations described under Section 3.2 and are not intended to supersede the design by the stmctural engineer. Other type of foundations may require additional evaluation and a review of the recommendations presented herein. Based on the results of this investigation and our past experience, we recommend that the foundation design be prepared for the soil conditions presented in the Table 6.3.1 below. Actual as graded conditions will determine the appHcable foundation design criteria. Thus, it is important that the testing of soils near finish grade be performed during site grading to verify the actual subgrade conditions. BARRATT AMERICAN, INC. Geotechnical Evaluation Proposed Residential Building Project No. :2555-SD3 April 13, 2004 Page 8 TABLE 6.3.1 - MINIMUM DESIGN REQUIREMENTS DESIGN PARAMETER E.L < 20 P.L < 15 E.I. > 20 P.L < 15 E.L > 20 15 < P.I. < 20 Foundation Depth or Minimum Perimeter Beam depth (inches below lowest adjacent grade) One Story - 12 Two story-18 One Story - 12 Two story-18 One Story - 12 Two story-18 Foimdation Width (Inches) One Story - 12 Two story-15 One Story - 12 Two story-15 One Story - 12 Two story-15 Maximum Beam Spacing (feet) NA 25 22 lc (Cantilevered length as soil function) NA 0 2.1 Minimum Slab Thickness (inches) 4 4 4 Presaturation of subgrade soil (Percent of Optimum/Depth in inches) Subgrade to be well wetted before pouring concrete 100/18 120/18 An allowable bearing capacity of 2500 poimds per square foot (psf), including both dead and live loads, may be used if footings are designed in accordance with the table. The allowable bearing value may be increased by one-third when considering short-term Uve loads (e.g. seismic and wind loads). The passive earth pressure may be computed as an equivalent fluid having a density of 200 psf per foot of depth, to a maximum earth pressure of 3000 psf A coefficient of fiiction between soil and concrete of 0.35 may be used with dead load forces. When combining passive pressure and frictional resistance, the passive pressure component should be reduced by one-third. 6.3.2 Seismic Design Parameters Seismically resistant stmctural design in accordance with local building ordinances should be followed during the design of all stractures. Building Codes have been developed to minimize stractural damage. However, some level of damage as the result of ground shaking generated by nearby earthquakes is considered likely in this general area. For the purpose of seismic design a Type B seismic source located approximately 10 km from the site may be used. Table below presents seismic design factors in keeping with the criteria presented in the 2001 CBC, Division IV & V, Chapter 16. BARRATT AMERICAN, INC. Geotechnical Evaluation Proposed Residential Building Project No.: 2555-SD3 April 13, 2004 Page 9 TABLE 6.3.2- SEISMIC DESIGN PARAMETERS Parameters Soil Profile Type Ca Cv Na Nv Seismic Source Type Source Table 16-J 16-Q 16-R 16-S 16-T 16-U Value Sc 0.40 0.56 1.0 1.0 B 6.3.3 Foundation Set Backs Where applicable, the following setbacks should apply to all foundations. Any improvements not conforming to these setbacks may be subject to lateral movements and/or differential settlements: > The outside bottom edge of all footings should be set back a minimum of H/3 (where H is the slope height) from the face of any descending slope. The setback should be at least 7 feet and need not exceed 20 feet. > The bottom of all footings for stractures near retaining walls should be deepened so as to extend below a 1:1 projection upward from the bottom inside edge ofthe wall stem. > The bottom of any existing foundations for stractures should be deepened so as to extend below a 1:1 projection upward from the bottom of the nearest excavation. 6.3.4 Slab-on-Grade Construction Where applicable, concrete slabs should be a minimum of 4 inches thick and reinforced as per stractural engineer requirements. Control joints should be provided to help minimize random cracking. Where moisture condensation is undesirable, all slabs should be underlain with a minimum 10 mil polyvinyl chloride membrane, sandwiched between two layers of clean sand, S.E. 30 or greater, each being at least two inches thick. Care should be taken to adequately seal all seams and not puncture or tear the membrane. The sand should be proof rolled. Subgrade should be well wetted prior to placing concrete. 6.3.5 Subgrade Moisture It moisture condensation is undesirable, all slabs should be underlain with a minimum 10-mil polyvinyl chloride membrane, sandwiched between two layers of clean sand (SE above 25) each being at least two inches thick. Care should be taken to adequately seal all seams and not puncture or tear the membrane. The sand should be proof rolled. Subgrade soils should be wetted prior to placing concrete. i5> BARRATT AMERICAN, INC. Geotechnical Evaluation Proposed Residential Building Project No.:2555-SD3 April 13, 2004 Page 10 6.3.6 Soil Corrosivity Due to the proposed grade changes throughout the site, the soil resistivity was not tested during this field investigation. It is recommended that a conosion engineer be consulted to provide recommendations for proper protection of buried metal pipes at this site. 6.3.7 Pavement Design R- Value testing was not performed as a part of this study. The pavement sections presented herein are calculated based on the design standards included in the Califomia Department of Transportation "Highway Design Manual", fifth edition and an assumed R-Value of 20. It is recommended that the subgrade be prepared in accordance with Section 6.2.2 of this report, however, the top 12 inches of subgrade and all aggregate base materials should be compacted to a minimum of 95 percent of maximum dry density, as determined in accordance with ASTM Test Method D1557-00. Pavement sections may increase or decrease based on actual soil conditions and R-value testing performed at the grading. TABLE 6.3.3- PRELIMINARY PAVEMENT DESIGN Street Type Traffic Index R-value Calculated Pavement Section (Inches) City Mimmum Section Parking Areas 4.5 20 4 AC / 2.5 AB 4 AC/4 AB Local Street 5.0 20 4 AC / 4.0 AB 4AC/4AB AC is asphalt concrete conforming to Caltrans Standard Specifications. AB is aggregate base conforming to the requirements of Caltrans 'Class II Aggregate Base'. We also recommend that a minimum of 6 inches of Portland Cement Concrete (PCC) pavements be used in track loading areas and frash dumpster pads and approaches. The pavement concrete section should be adequately reinforced and may be placed directly on compacted subgrade. 6.4 SITE DRAINAGE The need to maintain proper surface and subsurface drainage systems cannot be overly emphasized. Due to the highly expansive nature of the underlying materials, water should not be allowed to pond and should be directed away from foundations and hardscape. BARRATT AMERICAN, INC. Geotechnical Evaluation Proposed Residential Building Project No.: 2555-SD3 April 13,2004 Page 11 6.5 RETAINING WALL DESIGN AND CONSTRUCTION 6.5.1 General Design Criteria An allowable bearing capacity of 2,000 pounds per square foot, including both dead and live loads, may be used if footings are founded at a minimum of 18 inches into compacted fill and/or dense formational materials. The allowable bearing may be increased by one-third when considering short-term live loads (e.g. seismic and wind loads). The passive resistance may be computed as an equivalent fluid pressure having a density of 150 psf per foot of depth, to a maximum earth pressure of 2,000 psf A coefficient of finction between soil and concrete of 0.35 may be used with dead load forces. When combining passive pressure and fiictional resistance, the passive pressure component should be reduced by one-third. An equivalent fluid pressure approach may be used to compute the horizontal active pressure against the proposed walls. The appropriate fluid unit weights are given in Table 6.3.3 below for specific slope gradients of retained materials. TABLE 6.3.4 - ACTIVE EARTH PRESSURES Surface Slope of Retained Materials (H:V) Equivalent Fluid Pressure (PCF) Level 33 2:1 45 The above equivalent fluid weights do not include other superimposed loading conditions such as expansive soil, vehicular traffic, stractures, seismic conditions or adverse geologic conditions. 6.5.2 Wall Backflll and Drainage Selected onsite or import soil (SM/SW materials with EI<21 & PI<4) should be used for backfill provided they are screened of greater than 3-inch size gravels. Presence of other materials might necessitate revision to the parameters provided and modification of wall designs. The backfill materials should be placed in lifts no greater than 8-inches in thickness and compacted at 90% relative compaction in accordance with ASTM Test Method D1557- 00. Proper surface drainage needs to be provided and maintained. BARRATT AMERICAN, INC. Project No.: 2555-SD3 Geotechnical Evaluation April 13, 2004 Proposed Residential Building p^g^ 12 Retaining walls should be provided with an adequate pipe and gravel back drain system to prevent build up of hydrostatic pressures. Backdrains should consist of a 4-inch diameter perforated collector pipe embedded in a minimum of one cubic foot per Hneal foot of 3/8 to one inch clean crashed rock or equivalent, wrapped in filter fabric. The drain system should be connected to a suitable outlet. A minimum of two outlets should be provided for each drain section. Walls from 2 to 4 feet in height may be drained using localized gravel packs behind weep holes at 10 feet maximum spacing (e.g. approximately 1.5 cubic feet of gravel in a woven plastic bag). Wall drainage should comply with the minimum requirements by the wall designer or manufacturer. 6.6 PLAN REVIEW AND CONSTRUCTION OBSERVATIONS We recommend that site grading, specifications, and foundation plans be reviewed by this office prior to constmction to check for conformance with the recommendations of this report. We also recommend that GeoTek representatives be present during site grading and foundation constraction to check for proper implementation of the geotechnical recommendations. These representatives should perform at least the following duties: • Observe site clearing and grabbing operations for proper removal of all unsuitable materials. • Observe and test bottom of removals prior to fill placement. • Evaluate the suitability of on-site and import materials for fill placement, and collect soil samples for laboratory testing where necessary. • Observe the fill for uniformity during placement including utility trenches. Also, test the fill for field density and relative compaction. • Observe and probe foundation materials to confirm suitability of bearing materials and proper footing dimensions. If requested, GeoTek will provide a constraction observation and compaction report to comply with the requirements of the govemmental agencies having jurisdiction over the project. We recommend that these agencies be notified prior to commencement of constraction so that necessary grading permits can be obtained. BARRATT AMERICAN, INC. Project No.: 2555-SD3 Geotechnical Evaluation April 13, 2004 Proposed Residential Building Page 13 7. LIMITATIONS The materials observed on the project site appear to be representative of the area; however, soil and bedrock materials vary in character between excavations and natural outcrops or conditions exposed during site constraction. Site conditions may vary due to seasonal changes or other factors. GeoTek, Inc. assumes no responsibility or liabiUty for work, testing or recommendations performed or provided by others. Since our recommendations are based the site conditions observed and encountered, and laboratory testing, our conclusion and recommendations are professional opinions that are limited to the extent of the available data. Observations during constraction are important to allow for any change in recommendations found to be wananted. These opinions have been derived in accordance with cunent standards of practice and no wananty is expressed or impUed. Standards of practice are subject to change with time. BARRATT AMERICAN, INC. Project No.: 2555-SD3 Geotechnical Evaluation April 13, 2004 Proposed Residential Building Page 14 8. SELECTED REFERENCES Afrouz, A., 1992, "Practical Handbook of Rock Mass Classifications Systems and Modes of Ground Failure," CRC Press, January 1992. ASTM, 200, "Soil and Rock: American Society for Testing and Materials," vol. 4.08 for ASTM test methods D-420 to D- 4914,153 standards, 1,026 pages; and vol. 4.09 for ASTM test method D-4943 to highest number. Blake, T., 2000a, "EQFAULT, version 3.00," a Computer Program for Deterministic Estimation of Maximum Earthquake Event and Peak Ground Acceleration. Blake, T., 2000, "FRISKSP, version 4.00," a Computer Program for Probabilistic Estimation of Peak Acceleration and Uniform Hazard Spectra Using 3-D Faults as Earthquake Sources. Bowels, J., 1982, "Foundation Analysis and Design," McGraw-Hill, Third Edition. California Code of Regulations, Title 24, 2001 "Califomia Building Code," 3 volumes. Califomia Division of Mines and Geology (CDMG), 1996, Open File Report 96-02, Geologic Maps of the Northwestem Part of San Diego County, Califomia, Plate 1-Oceanside, San Luis Rey, and San Marcos 7.5 Quadrangles, Plate 2- Encinitas and Rancho Santa Fe 7.5 Quadrangles. Califomia Division of Mines and Geology (CDMG), 1997, "Guidelines for Evaluating and Mitigating Seismic Hazards in California," Special Publication 117. Califomia Division of Mines and Geology (CDMG), 1998, Maps of Known Active Fault Near-Source Zones in California and Adjacent Portions of Nevada: Intemationai Conference of Building Officials. GeoTek, Inc., In-house proprietary information. Geocon Incorporated, 1999, "Geotechnical Investigation, SRWB Property, Carlsbad, Califomia." Geotechnical Exploration, Inc., 1996, "Report of limited Geotechnical Investigation and Updated Soil-Related Recommendations, Poinsettia Hills Project, (Southem Property Boundary), West of El Camino Real at Cassia Road, Carlsbad, Califomia." Ishihara, K., 1985, "Stability of Natural Deposits During Earthquakes," Proceedings of the Eleventh International Conference on Soil Mechanics and Foundation Engineering, San Francisco, CA, Volume 1. Pacific Soils Engineering, Inc., 1997, "Preliminary Geotechnical Investigation and Grading Plan Review, Poinsettia Hill, City of Carisbad, CA." Seed, H.B., and Idriss, I.M., 1982, "Ground Motions And Soil Liquefaction During Earthquakes," Earthquake Engineering Research Institute. US Army Corps of Engineers, No. 9, "Settlement Analysis," Technical Guidelines, ASCE Press, 1994 Youd, T. Leslie and Idriss, Izzmat M., 1997, Proceeding of the NCEER Workshop on Evaluation of Liquefaction Resistance of Soils, National Center for Earthquake Engineering Research, Technical Report NCEER-97-0022. TOPO! map printed on 03/08/04 from "California.tpo" and "Untitled,tpg" 117.30000° W 117.28333° W WGS84 117,26667° W 117.30000° W TNt/MN 13° 117.28333° W .5 WGS84 117,26667° VV 1 MILL lOOOFEET 0 500 1000 MElEflS Printprl fn-iTu TOPni |gl9nni Matinnal rTPnjJTapViir Hnli^iTiiJ.s (m^y tnpn nnm) Barratt American, Inc. SRWB Property South Side of Cassia Road, East of Poinsettia Lane Carlsbad, Califomia GeoTek Project Number: 2555SD3 USGS 7.5-Minute Topographic Map Figure 1 Site Location Map •K, INC. 1384 Poinsettia Avenue, Suite A Vista, California 92083 1--X :ict I'UF CJ p5% •F\i 21' '1; \\yd2o\ { [y^ \ \\\\ [ \ \(i o^mjf^hm Tl, i. y$m}. I i i7 i 'I 'My ^^v^0pyjy^/ yyj/iyi yy. a. ^ —: : 50 +—+ LEGEND Artificial Fill Alluvium Santiago Fonnation Approximate location of exploratory boring by GeoTek Inc. dated 3/2004 Approximate location of exploratory boring by Pacific Soils Engineeiing, Inc. dated 2/1997 Approximate location of exploratory boring by Geotechnical Exploration, Inc. dated 8/1996 Study Area Geologic Contact; queried where uncertain \\\ \ \ Base Map Prepared by Hunsaker & Associates, San Diego, January 2004. BARRATT AIMERICAN, INC. SRTO Property South Side of Cassia Road, East of Poinsettia Lane Carlsbad, Califomia Geotechnical Map 1384 poinsettia Avenue, Suite A, Vista, Califomia 920S3 Geo Tek Froject No.: 2555SD3 Date: 4/7004 SRWB PROPERTY GEOLOGIC SECTION AA Scale: Horiz: linch = 100 feet Vert: linch = 20 feet Sta 9+00 Sta 10+00 Sta 11+00 Sta 12+00 Sta 13+00 Sta 14+00 Sta 15+00 Boring Legend Borehole No Depth Below Ex. Ground Level (ft) 280 260 Circle dashed if projected Existing Ground Eievation (ft) Soil Legend Groundwater (El) Note: • Refer to logs of borings for detailed description of soil conditions and SPT results. BARRATT AMERICAN, INC SRWB Property South Side of Cassia Road, East of Poinsettia Lane Carlsbad. Califomia Figure 3 ' ^^8K, IMC. 1384 Poinsettia Avenue, Suite A Vista, CaHfomia 92083 BARRATT AMERICAN, INC SRWB Property South Side of Cassia Road, East of Poinsettia Lane Carlsbad. Califomia Geologic Cross Section - AA-' ^^8K, IMC. 1384 Poinsettia Avenue, Suite A Vista, CaHfomia 92083 PN: 2555SD3 April, 2004 Geologic Cross Section - AA-' ^^8K, IMC. 1384 Poinsettia Avenue, Suite A Vista, CaHfomia 92083 o ••G a > "a u u V > Boring Legend Borehole No Depth Below Ex. Ground Level (ft) GENERALIZED GEOLOGIC SECTION BB Scale: Horiz: linch = 100 feet Vert: linch = 20 feet 260 240 220 200 Sta 8+00 260 - 240 -220 ••-200 Sta 9+00 Sta 10+00 Sta 11+00 Sta 12+00 Sta 13+00 Sta 14+00 Circle dashed if projected Existing Ground Elevation (ft) Soil Legend Groundwater (El) BARRATT AMERICAN, INC SRWB Property South Side of Cassia Road, East of Poinsettia Lane Carlsbad. Califomia PN: 2555SD3 April, 2004 Note: • Refer to logs of borings for detailed description of soil conditions and SPT results. Figure 4 Generalized Geologic Cross Section -BB- 5K, IMC. 1384 Poinsettia Avenue, Suite A Vista, CaHfomia 92083 APPENDIX A LOGS OF EXPLORATORY BORINGS (Borings B-1 to B-8, This Study) (Borings B-5 to B-6 from Pacific Soils Engineering, Inc.) (Boring B-2 from Geotechnical Exploration, Inc.) Proposed Residential Building Carlsbad, California Project No.: 2555-SD3 I BARRATT AMERICAN, Inc. APPENDIX A Geotechnical Evaluation April 13, 2004 Proposed Residential Building Page A-1 LEGEND TO FIELD TESTING AND SAMPLING A - FIELD TESTING AND SAMPLING PROCEDURES The Standard Penetration Test (SPT) The SPT is performed in accordance with ASTM Test Method D 1586-99. The SPT sampler is typically driven into the ground 12 or 18 inches with a 140-pound hammer free falling from a height of 30 inches. Blow counts are recorded for every 6 inches of penetration as indicated on the log of boring. The split-barrel sampler has an extemal diameter of 2 inches and an unlined intemal diameter of 1-3/8 inches. The samples of earth materials collected in the sampler are typically classified in the field, bagged, sealed and transported to the laboratory for further testing. The Modified Split-Barrel Sampler (Rins) The Ring sampler is driven into the ground in accordance with ASTM Test Method D 3550-84. The sampler, with an extemal diameter of 3.0 inches, is lined with 1-inch long, thin brass rings with inside diameters of approximately 2.4 inches. The sampler is typically driven into the ground 12 or 18 inches with a 140-pound hammer free falling from a height of 30 inches. Blow covmts are recorded for every 6 inches of penetration as indicated on the log of boring. The samples are removed from the sample barrel in the brass rings, sealed, and transported to the laboratory for testing. Large Bulk Samples These samples are normally cloth bags of representative earth materials over 20 pounds in weight collected from the field by means of hand digging or exploratory cuttings. Small Bulk Samples These samples are normally airtight plastic bags that are typically less than 5 pounds in weight of representative earth materials collected from the field by means of the split spoon sampler, hand digging or exploratory cuttings. These samples are primarily used for determining natural moisture content and classification indices. B - BORING LOG LEGEND The following abbreviations and symbols often appear in the classification and description of soil and rock on the logs of borings: SOILS USCS Unified Soil Classification System f-c Fine to coarse f-m Fine to medium GEOLOGIC B: Attitudes Bedding: strike/dip J: Attitudes Joint: strike/dip C: Contact line Dashed line denotes USCS material change Solid Line denotes unit / formational change Thick solid line denotes end of boring (Additional denotations and symbols are provided on the logs of borings) GeoTek, Inc. LOG OF EXPLORATORY BORING CLIENT: PROJECT NAME:" PROJECT NO.: LOCATION: Barratt American Inc. SRWB Property 2555-SD3 See Site Plan DRILLER; DRILL METHOD HAMMER N.G. ELEVATION Baja Exploration 8" Hollow Stem Auger 140lbw/30"drop ± 264 Feet LOGGED BY OPERATOR RIG TYPE DATE TGS Manny CME 75 w/cathead 3/10/2004 SAMPLES BORING NO.: B-1 MATERIAL DESCRIPTION AND COMMENTS > c o o Laboratorv Testing O a. o Fill B1 B1-2 SC 30 B1-3 10 Brown, moist, medium dense, clayey f-m SAND 3': becomes reddish brown, dense and gravelly I 6': becomes mottled olive-grey to tan and medium dense 4.9 21.6 CL B1-4 Brown, moist7very stifrsan^^^^^ 20.1 93 MD = 121.5pcfat 12.5% MC possibly disturbed 104 108 Pocket penetrometer (PPj = 2 tons/ft' Alluvium SC Tan to light brown, moist, medium dense, clayey fine SAND B1-5 Santiago Formation SM Highly weathered: Light-grayish tan, dry to moist, very dense, silty fine SAND; orange mottling, weakly cemented B1-6 17.3 106 25 50/6 Bl-7 same- 60/6 B1-8 same- HOLE TERMINATED AT 25.5 FEET Hole baclcfilled with bentonite No groundwater encountered Sample tvoe: -Ring -SPT -Small Bulk ^ —Large Bulk | | —No Recovery S -Water Table Lab testina: AL = Atterberg Limits SR - Sulfate/Resistivlty Test El = Expansion Index SH = Shear Test SA = Sieve Analysis CO = Consolidation test RV= R-Value Test MD = Maximum Density GeoTek, Inc. LOG OF EXPLORATORY BORING CLIENT: PROJECT NAME:" PROJECT NO.: LOCATION: Barratt American Inc. SRWB Property 2555-SD3 See Site Plan DRILLER DRILL METHOD HAMMER N.G. ELEVATION Baja Exploration 8' Hollow Stem Auger 140 lbw/30"drop ± 240 Feet LOGGED BY: OPERATOR: RIG TYPE DATE TGS Manny CME 75 w/cathead 3/10/2004 SAMPLES BORING NO.: B-2 MATERIAL DESCRIPTION AND COMMENTS o o Laboratory Testing O CL Q 15 B2-1 B2-2 SC Fill Tan to light-brown, moist, dense, clayey fine SAND 14.2 SM Light-gray, dry to moist, medium dense, clayey fine SAND; orange mottling B2-3 SC Light-brown, moist, medium dense, clayey fine SAND B2-4 19.2 CL Dark-brown, moist, very stiff, sandy CLAY B2-5 15': becomes brown, hard B2-6 17.4 116 115 107 PP = 2.5-4.0 PP = 2.5-3.5 25 Alluvium SC B2-7 Reddish-brown to dark gray, moist, dense clayey f-m SAND; with organics same- B2-8 15.6 118 (Continued) Sample type: -Ring -SPT 0-•Small Bulk -Large Bulk • -No Recovery ^ —Water Table Lab testina: AL = Atterberg Limits SR = Sulfale/Resistivity Test El = Expansion Index SH = Shear Test SA = Sieve Analysis CO = Consolidation test RV= R-Value Test MD = Maximum Densiiy GeoTek, Inc. LOG OF EXPLORATORY BORING CLIENT: PROJECT NAME:" PROJECT NO.: LOCATION: Barratt /American Inc. SRWB Property 2555-SD3 See Site Plan DRILLER DRILL METHOD HAMMER: N.G. ELEVATION Baja Exploration 8" Hollow Stem Auger 140 lb w/30" drop ± 240 Feet LOGGED BY OPERATOR RIG TYPE DATE TCS Manny CME 75 VK/cathead SAMPLES tl (0 3 UJ z in o to ID BORING NO.: B-2 (continued) MATERIAL DESCRIPTION AND COMMENTS Laboratory Testing o o 30 35 10 10 10 SC Gray-brown, moist to wet, medium dense, clayey f-m SAND B2-9 SC Light-gray, moist to wet, dense, clayey fine SAND; orange mottling 40 10 12 20 B2-10 SM Light-gray to tan, moist, dense, silty fine SAND 10 15 18 82-11 HOLE TERMINATED AT 41.5 FEET - Hole backfilled with bentonite No groundwater observed 45- 50 55 Sample type: -Ring -SPT -Small Bulk -Large Bulk • -No Recovery -Water Table Lab testing: /y. = Attertjerg Limits SR = Sulfate/Resistivily Test El = Expansion Index SH = Shear Test SA = Sieve Analysis CO = Consolidation test RV= R-Value Test MD = Maximum Density GeoTek, Inc. LOG OF EXPLORATORY BORING CLIENT: PROJECT NAME:" PROJECT NO.: LOCATION: Barratt American Inc. SRWB Property 2555-SD3 See Site Plan DRILLER DRILL METHOD HAMMER N.G. ELEVAnON: Baja Exploration 8" Hollow Stem Auger 140 Ibw/30" drop ± 244 Feet LOGGED BY OPERATOR: RIG TYPE DATE TCS Manny GME 75 3/10/2004 SAMPLES BORING NO.: B-3 MATERIAL DESCRIPTION AND COMMENTS 5 £ > c Laboratory Testing SC Fill Tan to light-brown, moist, medium dense, clayey fine SAND; mottled colorlna B3-3 B3-4 @5': becomes dark-gray, very dense ! 8': becomes dry to moist, dense 11.4 B3-5 same-15.9 B3-6 117 119 Alluvium SC B3-7 Dark-brown, moist, very dense, clayey fine SAND; w/ rootlets SC -same- B3-8 Continued) Sample type: -Ring —SPT 0 -Small Bulk -Large Bulk • -No Recovery —Water Table Lab testina: AL = Atterberg Limits SR = Sulfate/Resistivity Test El = Expansion Index SH = Shear Test SA = Sieve /\nalysis CO = Gonsolidation test RV= R-Value Test MD = Maximum Density GeoTek, Inc. LOG OF EXPLORATORY BORING CLIENT: PROJECT NAME:' PROJECT NO.: LOCATION: Barratt American Inc. SRWB Property 2555-SD3 See Site Plan DRILLER DRILL METHOD: HAMMER N.G. ELEVATION Baja Exploration 8" Hollow Stem Auger 140 Ibw/30" drop ± 244 Feet LOGGED BY OPERATOR: RIG TYPE DATE TCS Manny CME 75 SAMPLES tl BORING NO.: S-3 (continued) MATERIAL DESCRIPnON AND COMMENTS Lajjoratory Testing « 'g' O a a £ o 30' 35 10 13 20 SC Dark-brown, moist, dense, clayey fine SAND 83-9 10 14 19 ! 35': becomes light-brown 83-10 Santiago Formation SM 40' 20 28 35 Light-grayish tan, dry to moist, very dense, silty fine SAND; orange mottling B3-11 45 50 55 HOLE TERMINATED AT 41.5 FEET Hole backfilled with bentonite No groundwater observed Sample type: -Ring -SPT 0-Small Bulk -Large Bulk • -No Recovery —Water Table Lab testing: AL = Atterberg Limits SR = Sulfale/Resistivity Test El = Expansion Index SH = Shear Test SA = Sieve /^alysis CO = Consolidation test RV= R-Value Test MD - Maximum Density GeoTek, Inc. LOG OF EXPLORATORY BORING CLIENT: PROJECT NAME:' PROJECT NO.: LOCATION: Barratt American Inc. SRWB Property 2555-SD3 See Site Plan DRILLER DRILL METHOD: HAMMER N.G. ELEVATION Baja Exploration 8" Hollow Stem Auger 140 Ibw/30" drop ± 248 Feet LOGGED BY OPERATOR RIG TYPE DATE TCS Manny CME 75 3/10/2004 SAMPLES BORING NO.: B-4 MATERIAL DESCRIPTION AND COMMENTS I ^ > c o O Laboratory Testing o SM Fill Tan to light brown, moist, dense, silty f-m SAND @6': becomes mottled 10 • 18.1 8 18 30 84-4 MD = 121.5pcfat13.5% MC 102 HOLE TERMINATED AT 11.5 FEET Hole backfilled with bentonite No groundwater observed 15 - 20 - 25 Sample tvpe: -Ring -SPT 0 -Small Bulk -Large Bulk • -No Recovery -Water Table Lab testing: KL = Atterberg Limits SR = Sulfate/Resistivity Test El = Expansion Index SH = Shear Test SA = Sieve Analysis CO = Consolidation test RV= R-Value Test MD - Maximum Density GeoTek, Inc. LOG OF EXPLORATORY BORING CLIENT: PROJECT NAME:_ PROJECT NO.: LOCATION: Barratt American Inc. SRWB Property 2555-SD3 See Site Plan DRILLER DRILL METHOD: HAMMER N.G. ELEVATION Baja Exploration 8" Hollow Stem Auger 140 Ibw/30" drop ± 252 Feet LOGGED BY OPERATOR RIG TYPE DATE TCS Manny CME 75 BORING NO.: B-5 MATERIAL DESCRIPTION AND COMMENTS I ^ > c o o Laboratory Testing a a. a O Light-brown, moist, dense, clayey fine SAND 14.5 Light-gray, moist, dense, silty fine SAND Light-brown, moist, dense, clayey fine SAND 10': becomes medium dense 20.2 116 HOLE TERIVIINATED AT 11.5 FEET Hole backfilled with bentonite No groundwater observed -Small Bulk -Large Bulk • -No Recovery -Water Table AL = Atterberg Limits SR = Sulfale/Resistivity Test El = Expansion Index SH = Shear Test SA = Sieve Analysis GO = Consolidation test RV= R-Value Test MD - Maximum Density GeoTek, Inc. LOG OF EXPLORATORY BORING CLIENT: PROJECT NAME:' PROJECT NO.: LOCATION: Ban^tt American Inc. SRWB Property 2555-SD3 See Site Plan DRILLER DRILL METHOD: HAMMER N.G. ELEVATION Baja Exploration 8" Hollow Stem Auger 140 Ibw/30" drop ± 256 Feet LOGGED BY OPERATOR RIG TYPE DATE TCS Manny CME 75 3/10/2004 SAMPLES tf 5i BORING NO.: 6-6 MATERIAL DESCRIPTION AND COMMENTS Laboratory Testing Q - o £ O SM Fill Tan to light-brown, moist, medium dense, silty fine SAND 10 - 86-1 86-2 @5': becomes mottled, dry to moist 15.3 @10': becomes brown, moist 107 HOLE TERMINATED AT 11.5 FEET Hole backfilled with bentonite No groundwater observed 15 - 20 25 - Sample type: —Ring -SPT -Small Bulk -Large Bulk • -No Recovery —Water Table Lab testing: AL = Atterberg Limits SR = Sulfate/Resistivity Test El = Expansion Index SH = Shear Test SA = Sieve /^alysls GO = Consolidation test RV= R-Value Test MD = Maximum Density GeoTek, Inc. LOG OF EXPLORATORY BORING CLIENT: PROJECT NAME:_ PROJECT NO.: LOCATION: Barratt /American Inc. SRWB Property 2555-SD3 See Site Plan DRILLER DRILL METHOD HAMMER N.G. ELEVATION Baja Exploration 8" Hollow Stem Auger 140 Ibw/30" drop ± 259 Feet LOGGED BY OPERATOR RIG TYPE DATE TCS Manny CME 75 3/10/2004 SAMPLES E E tn « o to 3 BORING NO.: B-7 MATERIAL DESCRIPTION AND COMMENTS ra OJ > c o O Laboratory Testing S o Q a. o 8 10 25 25 50/6 B7-1 87-2 B7-3 SC Fill Gray-brown, dry to moist, medium dense, clayey fine SAND 11.5 @3' becomes mottled El = 54 LL = 37 PL = 21 Pl= 16 109 Hole backfilled with bentonite - No groundwater observed 0 - 15 20 25 HOLE TERMINATED AT 5 FEET Sample type: -Ring -SPT -Small Bulk -Large Bulk • -No Recovery -Water Table Lab testing: AL = Atterberg Limits SR = Sulfate/Resistivity Test El = Expansion Index SH = Shear Test SA = Sieve Analysis CO = Gonsolidation test RV= R-Value Test MD = Maximum Density GeoTek, Inc. LOG OF EXPLORATORY BORING CLIENT: PROJECT NAME:^ PROJECT NO.: LOCATION: Barratt /American Inc. SRWB Property 2555-SD3 See Site Plan DRILLER DRILL METHOD: HAMMER: N.G. ELEVATION Baja Exploration 8° Hollow stem Auger 140lbvir/30"drop ± 263 Feet LOGGED BY OPERATOR RIG TYPE DATE TCS Manny CME 75 SAMPLES CL n E E BORING NO.: B-8 MATERIAL DESCRIPTION AND COMMENTS Laboratory Testing SM Fill Brown, dry to moist, medium dense, silty fine SAND 5- Santiago Formation SM 50/6 B8-1 Light-grayish tan, dry to moist, very dense, silty fine SAND; orange mottling, weakly cemented HOLE TERMINATED AT 8.5 FEET 10 - Hole backfilled with bentonite - No groundwater observed 15 20 • 25 Sample type: -Ring -SPT 0--Small Bulk -Large Bulk • -No Recovery S —Water Table Lab testing: M. = Attert)erg Limits SR = Sulfate/Resistivity Test El = Expansion Index SH = Shear Test SA = Sieve Analysis CO = Consolidation test RV= R-Value Test MD = Maximum Density GEOTECHNICAL BORING LOG SHEET 1 OF 2 PROJECT NO. 400575 DATE STARTED DATE FEsrtSHED DRILLER LEDEZMA DRILLING XYPE OF DRILL RIG BUCKET AUGER PROJECTNAME GROUND ELEV. GW DEPTH (FT) DRIVE WT. DROP Poinsettia Hill 223.0 "BORING DESIG. B- 5 LOGGED BY NORTHING EASTING DAM 3. ID UIU. 0-' <l- t/3 o 2 to GEOTECHNICAL DESCRIPTION LU — OO DC UJ o cc 1- Ol O I- 220- 5- 215- 10- 210- 15- 205- 20- - 200- PUSH SC SC CL/SC SC SAMPLE TYPES: IS DRIVE (RING) SAMPLE IS SPT (SPLIT SPOON) SAMPLE E BULK SAMPLE Q] TUBE SAMPLE TOPSOIL CLAYEY SAND, medium to dark brown, very moist, moderately loose; rooted. ALLUVIUM/COLLUVIUM (Qal/Qcol): CLAYEY SAND, light gray brown, very moist, moderately dense to slightly loose. @ 5.0 ft. light gray-brown mottled brownish red, moist, moderately dense; few rootlets; organic particles. @ 8.0 ft. SANDY CLAY to CLAYEY SAND, dark brown, moist, stiff. @ 10.0 ft. CLAYEY SAND. @ 12.5 ft. light brown. (3) 15.0 ft. light brown monled reddish brown. SCRIPPS FORMATION (Tse): SANDSTONE, light gray strongly mottled, damp, moderately hard to hard. CONTINUED. 19.3 103 83 18.0 110 92 17.9 109 89 21.0 106 97 I GROUNDWATER PACIFIC SOILS ENGINEERING, INC. PLATE A-5 400575 PROJECT NO. DATE STARTED DATE FINISHED ZZZZZZZZZZ DRILLER LEDEZMA DRll I INPi •TYPE OF DRILL RIG BUCKET AUGFR GEOTECHNICAL BORING LOG Poinsettia Hill PROJECT NAME GROUND ELEV. GW DEPTH (FT) DRJ\^ WT. DROP SHEET 2 OF 2 223.0 BORING DESIG. LOGGED BY NORTHING EASTING B- 5 DAM ^1= UlU. > UJ LU Ul 1 —1 0. < D OT O _l EO o O —I o I h- o| GEOTECHNICAL DESCRIPTiON LU ^ OO 5" o -SOT >-2 QQ z g iri<-i I-X OT (- LU O H- SCRIPPS FORMATION (Tsr^): Cnntinn^H- II^TT^T;^ 14.2 115 83 TOTAL DEPTH 26.0 FT. NO WATER, NO CAVING S/^MPLE TYPES: ^ DRP/E (RING) SAMPLE ^SPT (SPLIT SPOON) SAMPLE © BULK SAMPLE Q] TUBE SAMPLE I GROUNDWATER PACIFIC SOILS ENGINEERING, INC. PLATE A-5 GEOTECHNICAL BORING LOG 400575 PROJECT NO. DATE STARTED DATE FINISHED . DRILLER LEDEZMA DRILUNG TYPE OF DRILL RIG BUCKET AUGER SHEET 1 OF 2 PROJECT NAME GROUND ELEV. ' GW DEPTH (FT) DRIVE WT. DROP Poinsettia Hill 237.0 BORING DESIG. LOGGED BY NORTHING EASTING B- 6 DAM I — LUU. a— > LU LU <l-OT m O -I 00 oi GEOTECHNICAL DESCRIPTION OO 5" -=OT rr LU QQ Z o 3 C t/3 I OT t- LU O H- 5- 10- 15- 20- 235- 230- 225- 220- 215- PUSH PUSH SC SC CL SAMPLE TYPES: ^ DRIVE (RING) SAMPLE ^SPT (SPLIT SPOON) SAMPLE ^BULK <;AMPTF m TirRF <;AWPI F TOPSOIL- CLAYEY SAND, medium to dark brown, very moist, moderately loose; rooted. ALLUVIUM/COLLUVIUM (Qal/Qcol): CLAYEY SAND, light brown mottled reddish brown, very moist, loose to moderately dense; rootlets. 5.0 ft. moist, moderately dense. 9.4 104 85 @ 10.0 ft. light to medium brown mottled reddish brown, ~ moist, moderately to medium dense. 16.8 11 88 @ 1 5.0 ft. SANDY CLAY, light brown to tan. @ 17.0 ft. more CLAYEY, medium brown, moist to very moist. 18.5 @ 20.0 ft. SANDY, medium dense. CONTINUED. X GROUNDWATER 103 79 CON HYDR* 21.1 99 82 PACIFIC SOILS ENGINEERING, INC. 400575 STCHNISHED nRlLLER LEDEZMA DRILLING ^ OF DRILL RIG BUCKET AUGFR GEOTECHNICAL BORING LOG PROJECTNAME GROUND ELEV GW DEPTH (FT) DRIVE WT. DROP SHEET 2 OF 2 Poinsettia Hill 237.0 BORING DESIG LOGGED BY NORTHING EASTING B- 6 DAM GEOTECHNICAL DESCRIPTiON ALLUVIUM/COLLUVIUM (Qal/nrnll- r.nnfin..^r^. g/^Mpy CLAY, medium to coarse; few pebbles. 19.1 SCRIPPS FORMATION (Tse): Cl AYFY RAMngTOMC- gray strongly mottled brownish red, slightly moist, moderately hard; weathered. light LU — I- £22 OO SO 16.9 TOTAL DEPTH 31.0 FT. NO WATER, NO CAVING it CO a: LU QQ 100 12 z g 76 X OT (- LU O K CON, HYDRd 90 ^^PLETYPET DRIVE (RING) S.AMPLE ^SPT (SPLIT SPOON) SAMPLE SAMPLE CD TUBE SAMPLE IGROUNT)WATER PACIFIC SOILS ENGINEERING, INC. PLATE A-6 EQUIPMENT CME 55 Hollow Stem DIMENSION S TYPE OF EXCAVATION 8" diameter OATE LOGGED ^ 8-6-96 SURFACE ELEVATION See Map (± 240' MSL) GROUNDWATER DEPTH Not encountered LOGGED BY CKG :iniii[ 1 - FIELD DESCRIPTION AND CLASSIFICATION DESCRIPTION AND REMARKS (Grain size. Density, Moisture, Color) 11 =p-E • SILTY SAND. Loose to medium dense. Dry I'iiili^H to slightly damp. Mottled tan-brown-red. iii SANDY SILT. Loose to medium dense. Very moist. Brown. SM 10 - 15 -iHi 20 ML ALLUVIUM —sandier. Light brown. Ill : i 25 - FINE SAND with some silt. Medium dense. Moist. Tan. ALLUVIUM --seep? SH 3= O — s: 6.2 UJ o >~ «S I— _J <—' a: UJ 1— Q 100.3 21.2 21-. 6 100.2 101.4 15.5 19.2 23.1 106.7 102.9 a: t— a. o o a: 12.0 12.5 5 " z >-r= I— X — X a: ^ LU £ o 124 122 11.8 97.6 12.5 125 UJ vc 81 2= O a. z X o LxJ C_» 3 2: o _ -I o CD u 83 85 82 122 80 17 16 o LU UJ WATER TABLE ^ LOOSE BAG SAMPLE [U IN-PLACE SAMPLE 1 . DRIVE SAMPLE H STANDARD PENETRATION TEST JOB NAME 'Poinsettia HUls WATER TABLE ^ LOOSE BAG SAMPLE [U IN-PLACE SAMPLE 1 . DRIVE SAMPLE H STANDARD PENETRATION TEST SITE LOCATION W. of El Camino Real ^ Cassia Road, Carlsbad, California WATER TABLE ^ LOOSE BAG SAMPLE [U IN-PLACE SAMPLE 1 . DRIVE SAMPLE H STANDARD PENETRATION TEST JOB NUMBER 96-6975 FIGURE NUMBER lib REVIEWED BY LOG No. B-2 EQUIPMENT DIMENSION i TYPE OF EXCAVATION DATE LOGGED CME 55 Hollow Stem 8" Diameter 8-6-96 SURFACE ELEVATION GROUNDWATER DEPTH LOGGED BY See Map Not encountered CKG —. —1 30- FIELD DESCRIPTION AND CLASSIFICATION DESCRIPTION AND REMARKS (Grain size. Density, Moisture, Color) —noticeably harder I? 31' FINE SAND with iron oxide staining. Dense. Damp. White-orange. SANTIA60 FORMATIOW Bottom of hole @ 33' No water in bottom of hole after 2h hours = o SM 20.3 105.4 :E t— M tyi h— Q. O O 11.8 o .3 X >- X 3r 125 >- ^ Ut O 84 3 O —I o cn o 29 49 a o LU •a: — 3" 2" WATER TABLE ^ LOOSE BAG SAMPLE G] IN-PLACE SAMPLE H DRIVE SAMPLE E . STANDARD PENETRATION TEST JOB NAME Poinsettia Hills SITE LOCATION W. of El Camino Real g-Cassia Road, Carlsbad. California JOB NUMBER 96-6975 FIGURE NUMBER lie REVIEWED BY no LOG No. B-2 APPENDIX B RESULTS OF LABORATORY TESTING Proposed Residential Building Carlsbad, California Project No.: 2555-SD3 BARRATT AMERICAN, INC. APPENDIX B Geotechnical Evaluation April 13 2004 Proposed Residential Building p^gg g.j SUMMARY OF LABORATORY TESTING Classification Soils were classified visually according to the Unified Soil Classification System (ASTM Test Method D2487). The soil classifications are shown on the logs of exploratory borings in Appendix A. Atterberg Limits Liquid limit, plastic limit and plasticity index were determined in accordance with ASTM Test Method D4318. Results are shown on the logs of exploratory borings and included herein. Moisture-Density Relations Laboratory testing was performed on representative samples collected during the subsurface exploration. The laboratory maximum dry density and optimum moisture content for representative soil types were determined in general accordance with test method ASTM D1557. Test results are presented on Plates MD-1 and MD-2. Moisture-Density - (In Situ Moisture and Unit Weight) The field moisture content and dry unit weight were taken on ring samples (ASTM Test Method D2216). The dry unit weight is determined in pounds per cubic foot. The field moisture content is determined as a percentage of the dry unit weight. Results of these tests are presented on the logs of exploratory borings in Appendix A. Expansion Index Expansion hidex testing was performed on a representative near-surface samples. Testing was perfonned in general accordance with ASTM Test Method D4829. The results are shown on Plate EI-1. EK, li^?^ EXPANSION INDEX TEST (ASTM D4829) Project Name: Project Number: Project Location: SRWB Property 2555-SD3 Ring ld_ Ring Dia." 4" Ring I 1" Loading weiglit: 5516. grams DENSITY DETERMINATION A Weigiit of compacted sampie & ring 758.3 B Weight of ring 369.81 C Net weight of sample 388.49 D Wet Density, ib / ft3 (C'O.SOie) 117.2 E Dry Density, ib/ft3 (D/1.F) 105.7 SATURATION DETERMINATION F Moisture Content, % 10.9 G (E*F) 1151.3 H (E/167.232) 0.63 1 (1.-H) 0.37 J (62.4*1) 23.0 K (G/J)= L % Saturation 50.1 Tested/ Ctiectted By: Date Tested: Sample Source: Sample Description: DC Lab No 1205 READINGS DATE TIME READING 3/31/2004 8:27 0.16 3/31/2004 8:37 0.159 3/31/2004 8:38 0.163 3/31/2004 8:43 0.177 4/1/2004 7:24 0.214 3/31/2004 B7-1 @ 0-5' Grey clayey fine SAND Initial 10 min/Dry 1 min/Wet 5 min/Wet Random Final FINAL MOISTURE Weight ot wet sample &tare Weight ot dry sample & tare Tare % Moisture 200.09 181.24 8.26 10.9% Initial Moisture Wet Wgt 200.77 Dry Wgt 186.74 Tare 8.05 7.9% EXPANSION INDEX = (@50% SATURATION) 54 PLATE El -1 LIQUID AND PLASTIC LIMITS TEST REPORT 50 LIQUID LIMIT 110 39.3 38.9 38.5 38.1 37.7 37.3 36.9 36.5 36.1 35.7 35.3 10 NUMBER OF BLOWS 20 25 30 40 MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS Grey clayey fine SAND 37 21 16 Project No. 2555-SD3 Client: Barratt Project: SRWB Property • Location: B7-1 (a> 0-5' LIQUID AND PLASTIC LIMITS TEST REPORT GeoTek, Inc. Remarks: Plate AT- MAXIMUM DENSITY CURVE Project No.: 2555-SD3 Project: SRWB Property Location: B4 @ 1-5' Elev./Depth: Remarks: Date: 3/19/04 MATERIAL DESCRIPTION Description: Lt. Brown silty fine to medium SAND Classifications -USCS: AASHTO: Nat. Moist. = Sp.G. = Liquid Limit Plasticity Index = % > No.4 = % % < No.200 = TEST RESULTS Maximum dry density = 121.5 pcf Optimum moisture =13.5 % 140 130 120 Q. I IU CO c 0) -D Q 100 90 80 70 V Test specification: ASTM D 1557-00 Procedure A Modified ASTM D 1557-00 Procedure A Modified 1UU7o bAIUKAIlUN UUKVbta FOR SPEC. GRAV. EQUAL TO: 1UU7o bAIUKAIlUN UUKVbta FOR SPEC. GRAV. EQUAL TO: 2.8 2.7 2.6 2.8 2.7 2.6 2.8 2.7 2.6 2.8 2.7 2.6 :^ v^ 10 15 20 25 Water content, % GeoTek, Inc. 30 35 40 Plate MD-1 MAXIMUM DENSITY CURVE Curve No.: MD-2 Project No.: 2555-SD3 Project: SRWB Property Location: Bl@0-4' Elev./Depth: Remarks: MATERIAL DESCRIPTION Description: Brown clayey fine to medium SAND Date: 3/31/04 Classifications USCS: AASHTO: Nat. Moist. = Sp.G. = Liquid Limit Plasticity Index = % > No.4 = % % < No.200 = TEST RESULTS Maximum dry density = 121.5 pcf Optimum moisture = 12.5 % 140 130 120 Q. I IU 10 c 0) -o Q 100 90 80 70 \ Test specification: ASTM D 1557-00 Procedure A Modified ASTM D 1557-00 Procedure A Modified lUU7o bAIUKAIlUN UUKVtl£> hOK bPbC. UKAV. tUUAL 1 U: 2.8 2.7 2.6 2.8 2.7 2.6 2.8 2.7 2.6 2.8 2.7 2.6 10 15 20 25 Water content, % 30 -GeoTek, Inc.' 35 40 Plate MD-2 APPENDIX C GENERAL GRADING GUIDELINES Proposed Residential Building Carlsbad, California Project No.: 2555-SD3 GENERAL GRADING GUIDELINES APPENDIX c Geotechnical Evaluation 2555 SDS SRWB Property p^gg/ GENERAL GRADING GUIDELINES Guidelines presented herein are intended to address general construction procedures for earthwork construction. Specific situations and conditions often arise which cannot reasonably be discussed in general guidelines, when anticipated these are discussed in the text ofthe report. Often unanticipated conditions are encountered which may necessitate modification or changes to these guidelines. It is our hope that these will assist the contractor to more efficiently complete the project by providing a reasonable understanding of the procedures that would be expected during earthwork and the testing and observation used to evaluate those procedures. General Grading should be performed to at least the minimum requirements of goveming agencies, Chapters 18 and 33 ofthe Uniform Building Code and the guidelines presented below. Preconstruction Meeting A preconstruction meeting should be held prior to site earthwork. Any questions the contractor has regarding our recommendations, general site conditions, apparent discrepancies between reported and actual conditions and/or differences in procedures the contractor intends to use should be brought up at that meeting. The contractor (including the main onsite representative) should review our report and these guidelines in advance of the meeting. Any comments the contractor may have regarding these guidelines should be brought up at that meeting. Grading Observation and Testing 1. Observation of the fill placement should be provided by our representative during grading. Verbal communication during the course of each day will be used to inform the contractor of test results. The Contractor should receive a copy of the "Daily Field Report" indicating results of field density tests that day. If our representative does not provide the contractor with these reports, our office should be notified. 2. Testing and observation procedures are, by their nature, specific to the work or area observed and location of the tests taken, variability may occur in other locations. The contractor is responsible for the uniformity of the grading operations, our observations and test results are intended to evaluate the contractor's overall level of efforts during grading. The contractor's personnel are the only individuals participating in all aspect of site work. Compaction testing and observation should not be considered as relieving the contractor's responsibility to properly compact the fill. 3. Cleanouts, processed ground to receive fill, key excavations, and subdrains should be observed by our representative prior to placing any fill. It will be the Contractor's responsibility to notify our representative or office when such areas are ready for observation. 4. Density tests may be made on the surface material to receive fill, as considered warranted by this firm. GENERAL GRADING GUIDELINES APPENDIX c Geotechnical Evaluation 7^^- r,p,o SRWB Property PaVe 2 5. In general, density tests would be made at maximum intervals of two feet of fill height or every 1,000 cubic yards of fill placed. Criteria will vary depending on soil conditions and size ofthe fill. More frequent testing may be performed. In any case, an adequate number of field density tests should be made to evaluate the required compaction and moisture content is generally being obtained. 6. Laboratory testing to support field test procedures will be performed, as considered warranted, based on conditions encountered (e.g. change of material sources, types, etc.) Every effort will be made to process samples in the laboratory as quickly as possible and in progress construction projects are our first priority. However, laboratory workloads may cause in delays and some soils may require a minimum of 48 to 72 hours to complete test procedures. Whenever possible, our representative(s) should be infonned in advance of operational changes that might result in different source areas for materials. 7. Procedures for testing of fill slopes are as follows: a) Density tests should be taken periodically during grading on the flat surface of the fill three to five feet horizontally from the face ofthe slope. b) If a method other than over building and cutting back to the compacted core is to be employed, slope compaction testing during construction should include testing the outer six inches to three feet in the slope face to determine ifthe required compaction is being achieved. 8. Finish grade testing of slopes and pad surfaces should be performed after construction is complete. Site Clearing 1. All vegetation, and other deleterious materials, should be removed from the site. If material is not immediately removed fi-om the site it should be stockpiled in a designated area(s) well outside of all current work areas and delineated with flagging or other means. Site clearing should be performed in advance ofany grading in a specific area. 2. Efforts should be made by the contractor to remove all organic or other deleterious material from the fill, as even the most diligent efforts may result in the incorporation of some materials. This is especially important when grading is occurring near the natural grade. All equipment operators should be aware of these efforts. Laborers may be required as root pickers. 3. Nonorganic debris or concrete may be placed in deeper fill areas provided the procedures used are observed and found acceptable by our representative. Typical procedures are similar to those indicated on Plate G-4. Treatment of Existing Ground 1. Following site clearing, all surficial deposits of alluvium and colluvium as well as weathered or creep effected bedrock, should be removed (see Plates G-1, G-2 and G-3) unless otherwise specifically indicated in the text of this report. lib bk GENERAL GRADING GUIDELINES APPENDIX c Geotechnical Evaluation 2555-SD3 SRWB Propertv Pase 3 2. In some cases, removal may be recommended to a specified depth (e.g. flat sites where partial alluvial removals may be sufficient) the contractor should not exceed these depths unless directed otherwise by our representative. 3. Groundwater existing in alluvial areas may make excavation difficult. Deeper removals than indicated in the text of the report may be necessary due to saturation during winter months. 4. Subsequent to removals, the natural ground should be processed to a depth of six inches, moistened to near optimum moisture conditions and compacted to fill standards. 5. Exploratory back hoe or dozer trenches still remaining after site removal should be excavated and filled with compacted fill if they can be located. Subdrainage 1. Subdrainage systems should be provided in canyon bottoms prior to placing fill, and behind buttress and stabilization fills and in other areas indicated in the report. Subdrains should conform to schematic diagrams G-1 and G-5, and be acceptable to our representative. 2. For canyon subdrains, runs less than 500 feet may use six-inch pipe. Typically, runs in excess of 500 feet should have the lower end as eight-inch minimum. 3. Filter material should be clean, 1/2 to 1-inch gravel wrapped in a suitable filter fabric. Class 2 permeable filter material per Califomia Department of Transportation Standards tested by this office to verify its suitability, may be used without filter fabric. A sample of the material should be provided to the Soils Engineer by the contractor at least two working days before it is delivered to the site. The filter should be clean with a wide range of sizes. 4. Approximate delineation of anticipated subdrain locations may be offered at 40-scale plan review stage. During grading, this office would evaluate the necessity of placing additional drains. 5. All subdrainage systems should be observed by our representative during construction and prior to covering with compacted fill. 6. Subdrains should outlet into storm drains where possible. Outlets should be located and protected. The need for backflow preventers should be assessed during construction. 7. Consideration should be given to having subdrains located by the project surveyors. Fill Placement 1. Unless otherwise indicated, all site soil and bedrock may be reused for compacted fill; however, some special processing or handling may be required (see text of report). 2. Material used in the compacting process should be evenly spread, moisture conditioned, processed, and compacted in thin lifts six (6) to eight (8) inches in compacted thickness to obtain a uniformly dense layer. The fill should be placed and compacted on a nearly horizontal plane, unless otherwise found acceptable by our representative. 3. If the moisture content or relative density varies from that recommended by this firm , the Contractor should rework the fill until it is in accordance with the following: GENERAL GRADING GUIDELINES j PPFNnrv . Geotechnical Evaluation ^^^^O'f!;!^ SRWB Property Pa Je 4 a) Moisture content of the fill should be at or above optimum moisture. Moisture should be evenly distributed without wet and dry pockets. Pre-watering of cut or removal areas should be considered in addition to watering during fill placement, particulariy in clay or dry surficial soils. The ability of the conti-actor to obtain the proper moisture content will control production rates. b) Each six-inch layer should be compacted to at least 90 percent of the maximum dry density in compliance with the testing method specified by the conti-olling govemmental agency, hi most cases, the testing method is ASTM Test Designation D-1557. 4. Rock fragments less than eight inches in diameter may be utilized in the fill, provided: a) They are not placed in concentrated pockets; b) There is a sufficient percentage of fine-grained material to surround the rocks; c) The disti-ibution of the rocks is observed by and acceptable to our representative. 5. Rocks exceeding eight (8) inches in diameter should be taken off site, broken into smaller fragments, or placed in accordance with recommendations of this firm in areas designated suitable for rock disposal (See Plate G-4). On projects where significant large quantities of oversized materials are anticipated, altemate guidelines for placement may be included. If significant oversize materials are encountered during constinction, these guidelines should be requested. 6. hi clay soil dry or large chunks or blocks are common; if in excess of eight (8) inches minimum dimension then they are considered as oversized. Sheepsfoot compactors or other suitable methods should be used to break up blocks. When dry they should be moisture conditioned to provide a uniform condition with the surrounding fill. Slope Construction 1. The Confractor should obtain a minimum relative compaction of 90 percent out to the finished slope face of fill slopes. This may be achieved by either overbuilding the slope and cutting back to the compacted core, or by direct compaction of the slope face with suitable equipment. 2. Slopes frimmed to the compacted core should be overbuilt by at least three (3) feet with compaction efforts out to the edge of the false slope. Failure to properly compact the outer edge results in tiimming not exposing the compacted core and additional compaction after trimming may be necessary. 3. If fill slopes are built "at grade" using direct compaction methods then the slope constiuction should be performed so that a constant gradient is maintained throughout construction. Soil should not be "spilled" over the slope face nor should slopes be "pushed out" to obtain grades. Compaction equipment should compact each lift along the immediate top of slope. Slopes should be back rolled or otherwise compacted at approximately every 4 feet vertically as the slope is built. 4. Comers and bends in slopes should have special attention during constiuction as these are the most difficult areas to obtain proper compaction. GENERAL GRADING GUIDELINES APPENDIX c Geotechnical Evaluation 2555-SD3 SRWB Propertv p^ggj 5. Cut slopes should be cut to the finished surface, excessive undercutting and smoothing ofthe face with fill may necessitate stabilization. Keyways, Buttress and Stabilization Fills Keyways are needed to provide support for fill slope and various corrective procedures. 1. Side-hill fills should have an equipment-width key at their toe excavated through all surficial soil and into competent material and tilted back into the hill (Plates G-2, G-3). As the fill is elevated, it should be benched through surficial soil and slopewash, and into competent bedrock or other material deemed suitable by our representatives (See Plates G-1 G-2 and G- 3). 2. Fill over cut slopes should be constructed in the following manner: a) All surficial soils and weathered rock materials should be removed at the cut-fill interface. b) A key at least one (1) equipment width wide (or as needed for compaction) and tipped at least one (1) foot into slope should be excavated into competent materials and observed by our representative. c) The cut portion ofthe slope should be excavated prior to fill placement to evaluate if stabilization is necessary, the confractor should be responsible for any additional earthwork created by placing fill prior to cut excavation. (See Plate G-3 for schematic details). 3. Daylight cut lots above descending natiiral slopes may require removal and replacement of the outer portion ofthe lot. A schematic diagram for this condition is presented on Plate G-2. 4. A basal key is needed for fill slopes extending over natiiral slopes. A schematic diagram for this condition is presented on Plate G-2. 5. All fill slopes should be provided witii a key unless within tiie body of a larger overall fill mass. Please refer to Plate G-3, for specific guidelines. Anticipated butfress and stabilization fills are discussed in the text ofthe report. The need to stabilize other proposed cut slopes will be evaluated during constinction. Plate G-5 is shows a schematic of butfress constmction. 1. All backcuts should be excavated at gradients of 1:1 or flatter. The backcut configuration should be determined based on the design, exposed conditions and need to maintain a minimum fill width and provide working room for the equipment. 2. On longer slopes backcuts and keyways should be excavated in maximum 250 feet long segment. The specific configurations will be determined during constinction. 3. All keys should be a minimum of two (2) feet deep at the toe and slope toward the heel at least one foot or two (2%) percent whichever is greater. 4. Subdrains are to be placed for all stabilization slopes exceeding 10 feet in height. Lower slopes are subject to review. Drains may be required. Guidelines for subdrains are presented on Plate G-5. 5. Benching of backcuts during fill placement is required. GENERAL GRADING GUIDELINES APPENDIX c Geotechnical Evaluation 2555-SD3 SRWB Propertv pggg 5 Lot Capping 1. When practical, the upper three (3) feet of material placed below finish grade should be comprised of non-expansive or the least expansive material available onsite. Preferably, highly and very highly expansive materials should not be used. We will attempt to offer advise based on visual evaluations of the materials during grading, but it must be realized that laboratory testing is needed to evaluate the expansive potential of soil. Minimally, this testing takes two (2) to four (4) days to complete. 2. Transition lots (cut and fill) both per plan and those created by remedial grading (e.g. lots above stabilization fills, along daylight lines, above natural slope, etc.) should be capped with a three foot thick compacted fill blanket. 3. Cut pads should be observed by our representative(s) to evaluate the need for overexcavation and replacement with fill. This may be necessary to reduce water infiltration into highly fractured bedrock or other permeable zones, and/or due to differing expansive potential of materials beneath a structure. The overexcavation should be at least three feet. Deeper overexcavation may be recommended in some cases. UTILITY TRENCH CONSTRUCTION AND BACKFILL Utility french excavation and backfill is the contractors responsibility. The geotechnical consultant typically provides periodic observation and testing of these operations. While, efforts are made to make sufficient observations and tests to verify that the contractors' methods and procedures are adequate to achieve proper compaction, it is typically impractical to observe all backfill procedures. As such, it is critical that the contractor use consistent backfill procedures. Compaction methods vary for french compaction and experience indicates many methods can be successfiil. However, procedures that "worked" on previous projects may or may not prove effective on a given site. The confractor(s) should outiine the procedures proposed, so that we may discuss them prior to construction. We will offer comments based on our knowledge of site conditions and experience. 1. Utility french backfill in slopes, stinctural areas, in stieets and beneath flat work or hardscape should be brought to at least optimum moisture and compacted to at least 90 percent of the laboratory standard. Soil should be moisture conditioned prior to placing the tiench. 2. Flooding and jetting are not typically recommended or acceptable for native soils. Flooding or jetting may be used with select sand having a Sand Equivalent (SE) of 30 or higher. This is typically limited to the following uses: a) shallow (12 + inches) under slab interior frenches and, b) as bedding in pipe zone. The water should be allowed to dissipate prior to pouring slabs or completing tiench compaction. 3. Care should be taken not to place soils at high moisture content within the upper three feet of the french backfill in sfreet areas, as overly wet soils may impact subgrade preparation. GENERAL GRADING GUIDELINES APPENDIX c Geotechnical Evaluation 2555 SD3 SRWB Propertv p^gg 7 Moisture may be reduced to 2% below optimum moisture in areas to be paved within the upper three feet below sub grade. 4. Sand backfill should not be allowed in exterior frenches adjacent to and within an area extending below a 1:1 projection from the outside bottom edge of a footing, unless it is similar to the surrounding soil. 5. Trench compaction testing is generally at the discretion of the geotechnical consultant. Testing frequency will be based on french depth and the confractors procedures. A probing rod would be used to assess the consistency of compaction between tested areas and untested areas. If zones are foimd that are considered less compact than other areas, this would be brought to the confractors attention. JOB SAFETY General Personnel safety is a primary concem on all job sites. The following summaries our safety considerations for use by all our employees on muhi-employer constiuction sites. On ground personnel are at highest risk of injury and possible fatality on grading construction projects. The company recognizes that constinction activities will vary on each site and that job site safety is the conttactor's responsibility. However, it is, imperative that all personnel be safety conscious to avoid accidents and potential injury. In an effort to minimize risks associated with geotechnical testing and observation, the following precautions are to be implemented for the safety of our field personnel on grading and constiriction projects. 1. Safety Meetings: Our field personnel are directed to attend the conttactor's regularly scheduled safety meetings. 2. Safefy Vests: Safefy vests are provided for and are to be wom by our personnel while on the job site. 3. Safefy Flags: Safefy flags are provided to our field technicians; one is to be affixed to the vehicle when on site, the other is to be placed atop the spoil pile on all test pits. In the event that the contractor's representative observes any of our personnel not following the above, we request that it be brought to the attention of our office. Test Pits Location, Orientation and Clearance The technician is responsible for selecting test pit locations. The primary concem is the technician's safefy. However, it is necessary to take sufficient tests at various locations to obtain a representative sampling ofthe fill. As such, efforts will be made to coordinate locations with the grading confractors authorized representatives (e.g. dump man, operator, supervisor, grade checker, etc.), and to select locations following or behind the established fraffic pattem, preferable outside of current tiaffic. The 1. GENERAL GRADING GUIDELINES Geotechnical Evaluation SRWB Propertv APPENDIX c 2555-SD3 PaeeS contiactors authorized representative should direct excavation of the pit and safefy during the test period. Again, safefy is the paramount concern. Test pits should be excavated so that the spoil pile is placed away from oncoming tiaffic. The technician's vehicle is to be placed next to the test pit, opposite the spoil pile. This necessitates that the fill be maintained in a drivable condition. Altematively, the confractor may opt to park a piece of equipment in front of test pits, particulariy in small fill areas or those with limited access. A zone of non-encroachment should be established for all test pits (see diagram below) No grading equipment should enter this zone during the test procedure. The zone should extend outward to the sides approximately 50 feet from the center of the test pit and 100 feet in the direction of tiaffic flow. This zone is established both for safefy and to avoid excessive ground vibration, which typicaUy decreases test results. TEST PIT SAFETY PLAN TZT" TUT Test Pit sinp viFw Traffic Direction 10 Ofl Zone of Non-Encroachment PI AN -VIFW Vehicle parked here 50 ft Zone of Non-Encroachment Test Pit Spoil pile 50 ft Zone of Non-Encroachment Slope Tests When taking slope tests, the technician should park thefr vehicle directly above or below the test location on the slope. The conttactor's representative should effectively keep all equipment at a safe operation distance (e.g. 50 feet) away from the slope during testing. The technician is dfrected to withdraw from the active portion ofthe fill as soon as possible following testmg. The technician's vehicle should be parked at the perimeter of the fill in a highfy visible location. Trench Safety It is the confractor's responsibilify to provide safe access into frenches where compaction testing is needed. Trenches for all utilities should be excavated in accordance with CAL-OSHA and any other applicable safefy standards. Safe conditions will be required to enable compaction testing of the french backfill. GENERAL GRADING GUIDELINES APPENDIX c Geotechnical Evaluation 2555-SD3 SRWB Propertv Page 9 All utilify ttench excavations in excess of 5 feet deep, which a person enters, are to be shored or laid back. Trench access should be provided in accordance with OSHA standards. Our personnel are directed not to enter any ttench by being lowered or "riding down" on the equipment. Our personnel are directed not to enter any excavation which; 1. is 5 feet or deeper imless shored or laid back, 2. exit points or ladders are not provide, 3. displays any evidence of instabilify, has any loose rock or other debris which could fall into the tiench, or 4. displays any other evidence of any unsafe conditions regardless of depth. If the conttactor fails to provide safe access to tienches for compaction testing, our company policy requires that the soil technician withdraws and notifies thefr supervisor. The conttactors representative will then be contacted in an effort to effect a solution. All backfill not tested due to safefy concems or other reasons is subject to reprocessing and/or removal. Procedures In the event that the technician's safefy is jeopardized or compromised as a result of the conttactor's failure to comply with any ofthe above, the technician is directed to inform both the developer's and conttactor's representatives. If the condition is not rectified, the technician is required, by company policy, to immediately withdraw and notify their supervisor. The conttactor's representative will then be contacted in an effort to effect a solution. No fiirther testing will be performed until the situation is rectified. Any fill placed in the interim can be considered unacceptable and subject to reprocessing, recompaction or removal. In the event that the soil technician does not comply with the above or other established safefy guidelines, we request that the conttactor bring this to technicians attention and notify our project manager or office. Effective communication and coordination between the conttactors' representative and the field technician(s) is sttongly encouraged in order to implement the above safefy program and safefy in general. The safefy procedures outiined above should be discussed at the conttactor's safefy meetings. This will serve to inform and remind equipment operators of these safefy procedures particularly the zone of non-encroachment. ALTERNATE FINISH GRADE y^. SUITABLE! MATERIAL CONSTRUCT BENCHES ^ WHERE SLOPE EXCEEDS 5:1 BOTTOM OF CLEANOUT TO BE AT LEAST 1.5 TIMES THE WIDTH OF COMP.'S.CTION EQUIPMENT i^-.^ORIGlNAL GROUND _ tOOSEiSURFACEIMATERIALS SUITABLE MATERIAL 4 FT TYPICAL "6'" PERFORATED PIPE IN 9 CUBIC FEET PER LINEAL FOOT CLEAN GRAVEL WITH FILTER FABRIC TO COVER SURFACE OR COMPLETE WRAP PER FEILD CONDITIONS ALTERNATE ORIGINAL GROUND FINISH GPJ\DE SUITABLE MATERIAL :.{:QO:SE:SURFACE:tviAtERiAt: CONSTRUCT BENCHES VWERE SLOPE EXCEEDS 5:1 4 FT TV'PICAL SUITABLE _-'-p>5»^5'S MATERIAL BOTTOM OF CLEANOUT TO BE AT LEAST 1.5 TIMES THE WIDTH OF COMPACTION EQUIPMENT 6"' PERFORATED PIPE IN 9 CUBIC FEET PER LINEAL FOOT CLEAN GRAVEL WRAPPED IN FILTER FABRIC STANDARD GR-ADING GUIDELINES TYPICAL CA^'YON CLEANOUT GeoTek Insite. Inc. PLATE G-1 TYPICAL FILL SLOPE OVER NATUPJ^L DESCENDING SLOPE FINLSH G.RADE FILL SLOPE TOE OF FILL SLOPE PER PLAN PROJECT REMOVAL AT 1 TO 1 MIINIMUM 15 FTCLE.'S.R OR 1.5 EQUIPMENT WIDTHS FOR DAYLIGHT CUT AREA OVER NATURAL DESCENDING SLOPE STRUCTURAL SETBACK WITHOUT CORRECTIVE WORK IDAYUGHTCUT! (LINE PER PLAN! PROJECT REMOVAL AT 1 TO 1 MIN. 36" COMPACTED FILL :;;;;^::;;"^BEDROCK 2' MMN MIINIMUM 15 FT CLEAR OR 1.5 EQUIPMENT WIDTHS FOR COMPACTION ;'s; ^; ^ ^•:; s ^BEDROCK STANDARD GR.4DING GUIDELINES TREATMENT ABOVE NATURAL: SLOPES GeoTek Insite, Inc. PLATE G- 2 TYPICAL FILL SLOPE OVFR PROPOSED CUT SLOPF TYPICAL FILL SLOPE SLOPE MINIMUM fvllNIMUM HEIGHT KEY WIDTH KEY DEPTH 5 7 1 10 10 1.5 15 15 2 20 15 2.5 25 15 3 >25 SEE TEXT ENGINEER PRIOR TO CONSTRUCTiON STANDARD GR.ADING GUIDELINES COMMON FILL SLOPE KE^YS GeoTek Ins ite, Inc. PLATE G- 3 CROSS SECTIONAL VIEW FINISH GRADE ^y/yym--'^--y^ -£ \ \ T X 15' 3' f ^x::;:;:;::x:MHN J. -y STAGGER ROWS ^ HORIZONTALLY--v^ | J '^[^ —y^ X-MIINIMUM 15 FT CLEAR OR 1.5 EQUIPMENT WIDTHS FOR COMPACTION PLAN VEIW FILL SLOPE I MIINIMUM 15 FT CLEAR OR 1.5 EQUIPMENT WIDTHS FOR COMPACTION PLACE ROCKS END TO END. DO NOT PILE OR STACK. aipiiM' MIINIMUM 15 FT CLEAR OR 1.5 EQUIPMENT WIDTHS FOR COMPACTION IP llllll iiii^ IIP t SOIL TO BE PLACED AROUND AND OVER ROCKS AND FLOODED INTO VOIDS.COMPACT AROUND AND OVER "EACH WINDROW NOTES: 1) MINiNUM SOIL FILL OVER WINDROWS SHOULD BE 7 FEET AND SUFFICIENT FOR FUTURE EXCAVATIONS (e o SWIMMIING POOLS^ TO AVOID ROCKS. 2) MAXIMUM ROCK SIZE IN WINDROWS IS 4 FEET MINIMUM DIAMETER. 3) SOIL AROUND WINDROWS TO BE SANDY MATERIAL SUBJECT TO ACCEPTANCE BY SOIL ENGINEER 41 ALL SPACING AND CLEARANCES MUST BE SUFFICIENT TO .ALLOW FOR PROPER COMPACTION. STA.ND.4RD GRADING GUIDELINES ROCK BURIAL DETAILS GeoTek Insite, Inc. PLATE G-4 GPJO,DE TO DRAIN FINISHED SLOPE FACE TERRACE DPvAIN .AS REQUIRED KEY TO BE MINIMUM 15 FT PLUS WIDTH OF TERRACE DRAINS OR 1.5 EQUIPMENT WIDTH USED FOR COMPACTION KEY TO BE fi^lNIMUM 2 FT DEEP OR PER REPORT 2% MINIMUM FALL 4" DIAMETER PERFORATED DRAIN PIPE PVC SCH. 40 OR EQUIVALENT IN 6 CUBIC FT DRAIN ROCK WRAPPED IN FILTER FABRIC NOTE: ADDITIONAL BACKDRAINS MAY BE RECOMMENDED 4" DIAMETER SOLID OUTLET LATERALS TO SLOPE FACE OR STORM DRAIN SYSTEM AT MAXIMUM 100 FT INTERVALS STANDARD GR.ADING GUIDELINES GeoTek Insite, Inc. BUTTRESS AND STABILIZATION SLOPES PLATE G-5