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HomeMy WebLinkAboutRP 04-26; SALMEN INSURANCE BUILDING; Redevelopment Permits (RP) (3)ENVIRONMENTAL IMPACT ASSESSMENT FORM - PART I (TO BE COMPLETED BY THE APPLICANT) CASE NO: DATE RECEIVED: (To be completed by staff) BACKGROUND 1. CASE NAME: ^AL^iMSts/ I ^^iCUft->6W6^;^. 3^\Ur>\^^ 2. APPLICANT: -SAP-T t^. ^H)TM ^ A) 3. ADDRESS AND PHONE NUMBER OF APPLICANT: (^^-2- SgcoN>p 5T F ITc-a) '7'^^- o^^oo ^vJo>t>j\-rAS ^ c::^ ^t^z^ 4. PROJECT DESCRIPTION: fWt? gTQgV Of^f=\c>^ ^0{L^l rJ^ * <SL>IT&.c> <DVE:(2^ <3fR4>OhJT> LgUcY^ pAp-l-g-tHq . SUMMARY OF ENVIRONMENTAL FACTORS POTENTL^LLY AFFECTED: Please check any of the environmental factors listed below that would be potentially affected by this project. This would be any environmental factor that has at least one impact checked "Potentially Significant Impact," or "Potentially Significant Impact Unless Mitigation Incorporated" in the checklist on the following pages. I I Land Use and Planning Transportation/Circulation [31 Public Services I I Population and Housing Biological Resources Utilities & Service Systems I I Geological Problems Energy & Mineral Resources |^ Aesthetics I I Water Q Hazards Cultural Resources I I Air Quality Noise Recreation l^^E- Mandatory Findings of Significance 1 Rev. 06/2000 ENVIRONMENTAL IMPACTS STATE CEQA GUIDELINES, Chapter 3, Article 5, Section 15063 requires that the City conduct an Environmental Impact Assessment to determine if a project may have a significant effect on the environment. The Environmental Impact Assessment appears in the following pages in the form of a checklist. This checklist identifies any physical, biological and human factors that might be impacted by the proposed project and provides the City with information to use as the basis for deciding whether to prepare an Environmental Impact Report (EIR), Negative Declaration, or to rely on a previously approved EIR or Negative Declaration. • A brief explanation is required for all answers except "No Impact" answers that are adequately supported by an information source cited in the parentheses following each question. A "No Impact" answer is adequately supported if the referenced information sources show that the impact simply does not apply to projects like the one involved. A "No Impact" answer should be explained when there is no source document to refer to, or it is based on project-specific factors as well as general standards. • "Less Than Significant Impact" applies where there is supporting evidence that the potential impact is not adversely significant, and the impact does not exceed adopted general standards and policies. • "Potentially Significant Unless Mitigation Incorporated" applies where the incorporation of mitigation measures has reduced an effect from "Potentially Significant Impact" to a "Less Than Significant Impact." The developer must agree to the mitigation, and the City must describe the mitigation measures, and briefly explain how they reduce the effect to a less than significant level. • "Potentially Significant Impact" is appropriate if there is substantial evidence that an effect is significant. • Based on an "EIA-Part II", if a proposed project could have a potentially significant effect on the environment, but all potentially significant effects (a) have been analyzed adequately in an earlier EIR or Mitigated Negative Declaration pursuant to applicable standards and (b) have been avoided or mitigated pursuant to that earlier EIR or Mitigated Negative Declaration, including revisions or mitigation measures that are imposed upon the proposed project, and none of the circumstances requiring a supplement to or supplemental EIR are present and all the mitigation measures required by the prior environmental document have been incorporated into this project, then no additional environmental document is required (Prior Compliance). • When "Potentially Significant Impact" is checked the project is not necessarily required to prepare an EIR if the significant effect has been analyzed adequately in an earlier EIR pursuant to applicable standards and the effect will be mitigated, or a "Statement of Overriding Considerations" has been made pursuant to that earlier EIR. • A Negative Declaration may be prepared if the City perceives no substantial evidence that the project or any of its aspects may cause a significant effect on the environment. Rev. 06/2000 • If there are one or more potentially significant effects, the City may avoid preparing an EIR if there are mitigation measures to clearly reduce impacts to less than significant, and those mitigation measures are agreed to by the developer prior to public review. In this case, the appropriate "Potentially Significant Impact Unless Mitigation Incorporated" may be checked and a Mitigated Negative Declaration may be prepared. • An EIR must be prepared if "Potentially Significant Impact" is checked, and including but not limited to the following circumstances: (1) the potentially significant effect has not been discussed or mitigated in an Earlier EIR pursuant to applicable standards, and the developer does not agree to mitigation measures that reduce the impact to less than significant; (2) a "Statement of Overriding Considerations" for the significant impact has not been made pursuant to an earlier EIR; (3) proposed mitigation measures do not reduce the impact to less than significant, or; (4) through the EIA-Part II analysis it is not possible to determine the level of significance for a potentially adverse effect, or determine the effectiveness of a mitigation measure in reducing a potentially significant effect to below a level of significance. A discussion of potential impacts and the proposed mitigation measures appears at the end of the form under DISCUSSION OF ENVIRONMENTAL EVALUATION. Particular attention should be given to discussing mitigation for impacts which would otherwise be determined significant. Rev. 06/2000 Issues (and Supporting Information Sources): (Supplemental documents may be referred to and attached) I. LAND USE AND PLANNING. Would the proposal:. a) Conflict with general plan designation or zoning? (Source #(s): ( ) b) Conflict with applicable environmental plans or policies adopted by agencies with jurisdiction over the project? ( ) c) Be incompatible with existing land use in the vicinity? ( ) d) Affect agricultural resources or operations (e.g. impacts to soils or farmlands, or impacts from incompatible land uses? ( ) e) Disrupt or divide the physical arrangement of an established community (including a low-income or minority community)? ( ) II. POPULATION AND HOUSING. Would the proposal: a) Cumulatively exceed official regional or local population projections? ( ) b) Induce substantial growth in an area either directly or indirectly (e.g. through projects in an undeveloped area or extension of major infrastructure)? ( ) c) Displace existing housing, especially affordable housing? ( ) III. GEOLOGIC PROBLEMS. Would the proposal result expose people to potential impacts involving: ^o\^S> Fault rupture? ( b) Seismic ground shaking? ( c) Seismic ground failure, including liquefaction? ( d) Seiche, tsunami, or volcanic hazard? ( e) Landslides or mudflows? ( f) Erosion, changes in topography or unstable conditions from excavation, grading, or fill? ( in or ) ) soil Potentially Potentially Less Than Significant Significant Significan Impact Unless t Impact Mitigation Incorporated No Impact • • • 2f • • • [Zl • • • [Zf • • • • • • r( • • • • • • • • • • • • • • • • • • • • • 0^ • • • • • • g) Subsidence of the land? ( • O Rev. 06/2000 Issues (and Supporting Information Sources): (Supplemental documents may be referred to and attached) h) Expansive soils? ( i) Unique geologic or physical features? ( IV. WATER. Would the proposal result in: a) Changes in absorption rates, drainage pattems, or the rate and amount of surface runoff? ( ) b) Exposure of people or property to water related hazards such as flooding? ( ) c) Discharge into surface waters or other alteration of surface water quality (e.g. temperature, dissolved oxygen or turbidity)? ( ) d) Changes in the amount of surface water in any water body? ( ) e) Changes in currents, or the course or direction of water movements? ( ) f) Changes in the quantity of ground waters, either through direct additions or withdrawals, or through interception of an aquifer by cuts or excavations or through substantial loss of groundwater recharge capability? ( ) g) Altered direction or rate of flow of groundwater? ( ) h) Impacts to groundwater quality? ( ) i) Substantial reduction in the amount of groundwater otherwise available for public water supplies? ( ) V. AIR QUALITY. Would the proposal: a) Violate any air quality standard or contribute to an existing or projected air quality violation? ( ) b) Expose sensitive receptors to pollutants? ( ) c) Alter air movement, moisture, or temperature, or cause any change in climate? ( ) d) Create objectionable odors? ( ) Potentially Potentially Less Than No Significant Significant Significan Impact Impact Unless t Impact Mitigation Incorporated • • • o • • • • o • 0 o • o 0 • o o • o o • 0 [Zf • 0 0 • 0 0 0 0 • 0 0 0 0 • 0 0 \7{ 0 0" 0^ Rev. 06/2000 Issues (and Supporting Information Sources): (Supplemental documents may be referred to and attached) VI. TRANSPORTATION/CIRCULATION. Would the proposal result in: a) Increased vehicle trips or traffic congestion? ( oPFi<i^ AP-r ^ ) b) Hazards to safety from design features (e.g. sharp curves or dangerous intersections) or incompatible uses (e.g. farm equipment)? ( ) c) Inadequate emergency access or access to nearby uses? ( ) d) Insufficient parking capacity on-site or off-site? ( e) Hazards or barriers for pedestrians or bicyclists? ( ) ) f) Conflicts with adopted policies supporting alternative transportation (e.g. bus tumouts, bicycle racks)? ( ) g) Rail, waterbome or air traffic impacts? ( VII. BIOLOGICAL RESOURCES. Would the proposal result in impacts to: a) Endangered, threatened or rare species or their habitats (including but not limited to plants, fish, insects, animals, and birds? ( ) b) Locally designated species (e.g. heritage trees)? ( ) c) Locally designated natural communities (e.g. oak forest, coastal habitat, etc.)? ( ) d) Wetland habitat (e.g. marsh, riparian and vernal pool)? ( ) e) Wildlife dispersal or migration corridors? ( ) VIII. ENERGY AND MINERAL RESOURCES. Would the proposal? a) Conflict with adopted energy conservation plans? ( ) b) Use non-renewable resources in a wasteful and inefficient manner? ( ) Potentially Potentially Less Than Significant Significant Significan Impact Unless t Impact Mitigation Incorporated No Impact 0 0 0 0 0 0 0 0 o 0 0 o 0 0 0 0 0 o 0 0 o 0 0 o 0 0 o 0 0 0 0 0 o 0 0 0 0 0 0 0 0 o / / \3( s7 "7 V / Rev. 06/2000 Issues (and Supporting Information Sources): (Supplemental documents may be referred to and attached) c) Result in the loss of availability of a known mineral resource that would be of future value to the region and the residents of the State? ( ) Potentially Significant Impact 0 Potentially Significant Unless Mitigation Incorporated 0 Less Than Significan t Impact No Impact IX. HAZARDS. Would the proposal involve: a) A risk of accidental explosion or release of hazardous substances (including, but not limited to: oil, pesticides, chemicals or radiation)? ( ) b) Possible interference with an emergency response plan or emergency evacuation plan? ( ) c) The creation of any health hazard or potential health hazards? ( ) d) Exposure of people to existing sources of potential health hazards? ( ) e) Increase fire hazard in areas with flammable brush, grass, or trees? ( ) X. NOISE. Would the proposal result in: a) Increases in existing noise levels? ( ) b) Exposure of people to severe noise levels? ( ) XI. PUBLIC SERVICES. Would the proposal have an effect upon, or result in a need for new or altered government services in any ofthe following areas: a) Fire protection? ( b) Police protection? ( c) Schools? ( d) Maintenance of public facilities, including roads? ( e) Other governmental services? ( ) 0 0 o 0 o • 0 0 o 0 0 0 o 0 o 0 0 0 0 0 o 0 0 o 0 0 0 0 0 0 0 0 0 0 0 0 rf 0- V XII. UTILITIES AND SERVICES SYSTEMS. Would the proposal result in a need for new systems or supplies, or substantial alterations to the following utilities: a) Power or natural gas? ( L^PG (z-Apg, ^XIST^:; b) Communications systems? ( ) 0 0 0 0 0 0 Rev. 06/2000 Issues (and Supporting Information Sources): (Supplemental documents may be referred to and attached) c) Local or regional water treatment or distribution facilities? ( UP6t^t^ ('^)C\S\\^&) d) Sfi^er_or septic tanks? ( e) Storm water drainage? ( f) Solid waste disposal? ( g) Local or regional water supplies? ( ) Potentially Significant Impact o o 0 o o Potentially Significant Unless Mitigation Incorporated 0 Less Than No Significan Impact t Impact 0 0 0 0 0 0^ 0 0 0 or 0 0" 0 XIII. AESTHETICS. Would the proposal: a) Affect a scenic or vista or scenic highway? ( ) b) Have a demonstrate negative aesthetic effect? ( ) c) Create light or glare? ( ) XIV. CULTURAL RESOURCES. Would the proposal: a) Disturb paieontological resources? ( ) b) Disturb archaeological resources? ( ) c) Affect historical resources? ( ) d) Have the potential to cause a physical change which would affect unique ethnic cultural values? ( ) e) Restrict existing religious or sacred uses within the potential impact area? ( ) XV. RECREATIONAL. Would the proposal: a) Increase the demand for neighborhood or regional parks or other recreational facilities? ( ) b) Affect existing recreational opportunities? ( o 0 0 o 0 0 o 0 0 o 0 0 o 0 0 0 0 0 o 0 0 0 0 0 o 0 0 0 0 0 0 rf Rev. 06/2000 XVI. MANDATORY FINDINGS OF SIGNIFICANCE. a) Does the project have the potential to degrade the [ | [ [ [ [ quality of the environment, substantially reduce the habitat of a fish or wildlife species, cause a fish or wildlife population to drop below self-sustaining levels, threaten to eliminate a plant or animal community, reduce the number or restrict the range of a r£u-e or endangered plant or animal or eliminate important examples of the major periods of California history or prehistory? b) Does the project have impacts that are individually | | [ [ | [ ^ limited, but cumulatively considerable? ("Cumulatively considerable" means that the incremental effects of a project are considerable when viewed in connection with the effects of past projects, the effects of other current projects, and the effects of probable future projects)? c) Does the project have environmental effects which will | | | | [ | cause the substantial adverse effects on human beings, either directly or indirectly? XVIL EARLIER ANALYSES. Earlier analyses may be used where, pursuant to the tiering, program EIR, or other CEQA process, one or more effects have been adequately analyzed in an earlier EIR or negative declaration. Section 15063(c)(3)(D). In this case a discussion should identify the following on attached sheets: a) Earlier analyses used. Identify earlier analyses and state where they are available for review. b) Impacts adequately addressed. Identify which effects from the above checklist were within the scope of and adequately analyzed in an earlier document pursuant to applicable legal standards, and state whether such effects were addressed by mitigation measures based on the earlier analysis. c) Mitigation measures. For effects that are "Less than Significant with Mitigation Incorporated," describe the mitigation measures which were incorporated or refined from the earlier document and the extent to which they address site- specific conditions for the project. Rev. 06/2000 DISCUSSION OF ENVIRONMENTAL EVALUATION Please use this area to discuss any of the environmental factors that were checked "No impact" yet lack any information citations and any factors that were checked "Potentially Significant Impact" or "Potentially Significant Impact Unless Mitigation Incorporated." The City has adopted a "Statement of Overriding Consideration" with regard to air quality and circulation impacts resulting from the normal buildout according to the General Plan. The following sample text is intended to guide your discussion of the impacts to these environmental factors. AIR OUALITY: The implementation of subsequent projects that are consistent with and included in the updated 1994 General Plan will result in increased gas and electric power consumption and vehicle miles traveled. These subsequently result in increases in the emission of carbon monoxide, reactive organic gases, oxides of nitrogen and sulfur, and suspended particulates. These aerosols are the major contributors to air pollution in the City as well as in the San Diego Air Basin. Since the San Diego Air Basin is a "non-attainment basin", any additional air emissions are considered cumulatively significant: therefore, continued development to buildout as proposed in the updated General Plan will have cumulative significant impacts on the air quality of the region. To lessen or minimize the impact on air quality associated with General Plan buildout, a variety of mitigation measures are recommended in the Final Master EIR. These include: 1) provisions for roadway and intersection improvements prior to or concurrent with development; 2) measures to reduce vehicle trips through the implementation of Congestion and Transportation Demand Management; 3) provisions to encourage altemative modes of transportation including mass transit services; 4) conditions to promote energy efficient building and site design; and 5) participation in regional growth management strategies when adopted. The applicable and appropriate General Plan air quality mitigation measures have either been incorporated into the design of the project or are included as conditions of project approval. Operation-related emissions are considered cumulatively significant because the project is located within a "non-attainment basin", therefore, the "Initial Study" checklist is marked "Potentially Significant Impact". This project is consistent with the General Plan, therefore, the preparation of an EIR is not required because the certification of Final Master EIR 93-01, by City Council Resolution No. 94-246, included a "Statement Of Overriding Considerations" for air quality impacts. This "Statement Of Overriding Considerations" applies to all subsequent projects covered by the General Plan's Final Master EIR, including this project, therefore, no further environmental review of air quality impacts is required. This document is available at the Planning Department. CIRCULATION: The implementation of subsequent projects that are consistent with and included in the updated 1994 General Plan will result in increased traffic volumes. Roadway segments will be adequate to accommodate buildout traffic; however, 12 full and 2 partial intersections will be severely impacted by regional through-traffic over which the City has no jurisdictional control. These generally include all freeway interchange areas and major intersections along Carlsbad Boulevard. Even with the implementation of roadway improvements, a number of intersections are projected to fail the City's adopted Growth Management performance standards at buildout. 10 Rev. 06/2000 To lessen or minimize the impact on circulation associated with General Plan buildout, numerous mitigation measures have been recommended in the Final Master EIR. These include 1) measures to ensure the provision of circulation facilities concurrent with need; 2) provisions to develop altemative modes of transportation such as trails, bicycle routes, additional sidewalks, pedestrian linkages, and commuter rail systems; and 3) participation in regional circulation strategies when adopted. The diversion of regional through-traffic from a failing Interstate or State Highway onto City streets creates impacts that are not within the jurisdiction of the City to control. The applicable and appropriate General Plan circulation mitigation measures have either been incorporated into the design of the project or are included as conditions of project approval. Regional related circulation impacts are considered cumulatively significant because of the failure of intersections at buildout of the General Plan due to regional through-traffic, therefore, the "Initial Study" checldist is marked "Potentially Significant Impact". This project is consistent with the General Plan, therefore, the preparation of an EIR is not required because the recent certification of Final Master EIR 93-01, by City Council Resolution No. 94-246, included a "Statement Of Overriding Considerations" for circulation impacts. This "Statement Of Overriding Considerations" applies to all subsequent projects covered by the General Plan's Master EIR, including this project, therefore, no further environmental review of circulation impacts is required. LIST OF MITIGATING MEASURES (IF APPLICABLE) ATTACH MITIGATION MONITORING PROGRAM (IF APPLICABLE) 11 Rev. 06/2000 STATE OF CALIFORNIA - TflPRESOURCES AGENCY DEPARTMENT OF FISH AND GAME ENVIRONMENTAL FILING FEE CASH RECEIPT DFG 753.5a (8-03) Lead Agency: City Of Carisbad 270742 Date: 05/11/2006 County / State Agency of Filing: San DlegO Project Title: Salmen Insurance Document No.: Project Applicant Name: Bart M. Smith Phone Number: (760) 753-2464 Project Applicant Address: 682 2nd St, Encinitas, CA 92024 Project Applicant (c/7ec/(appropr/afe 6ox): Local Public Agency |^ School District j | Other Special District | | State Agency |^ Private Entity CHECK APPLICABLE FEES: $850.00 $1,250.00 $850.00 $850.00 $25.00 ) Environmental Impact Report ) Negative Declaration ) Application Fee Water Diversion (Sfafe Wafer Resources Control Board Only) ) Projects Subject to Certified Regulatory Programs ) County Administrative Fee /) Project that is exempt from fees ' ^ TOTALRECEIVED Signature and title of person receiving payment: WHITE - PROJECT APPLICANT YELLOW - DFG/FASB PINK - LEAD AGENCY GOLDENROD - STATE AGENCY OF FILING PRELIMINARY GEOTECHNICAL EVALUATION 955 GRAND AVENUE CARLSBAD, SAN DIEGO COUNTY, CALIFORNIA FOR SALMEN INSURANCE 955 GRAND AVENUE CARLSBAD, CALIFORNIA 92008 W.O. 4397-A-SC JUNE 21, 2004 Geotechnical • Geologic • Environmental 5741 Palmer Way • Carlsbad, California 92008 • (760)438-3155 • FAX (760) 931-0915 June 21,2004 W.O. 4397-A-SC Salmen Insurance 955 Grand Avenue Carlsbad, California 92008 Attention: Mr. Phil Salvagio Subject: Preliminary Geotechnical Evaluation, 955 Grand Avenue, Carlsbad, San Diego County, California Dear Mr. Salvagio: In accordance with your request, GeoSoils, Inc. (GSI) has performed a preliminary geotechnical evaluation of the subject site. The purpose of the study was to evaluate the onsite soils and geologic conditions and their effects on the proposed site development from a geotechnical viewpoint. EXECUTIVE SUMMARY Based on our review ofthe available data (see Appendix A), field exploration, laboratory testing, and geologic analysis, business development of the property appears to be feasible from a geotechnical viewpoint, provided the recommendations presented in the text ofthis report are properly incorporated into the design and construction ofthe project. The most significant elements of this study are summarized below: • The proposed development will consist demolition ofthe existing one-story building and construction of a two-story structure, as well as underground utility Improvements. The first floor will be a parking facility with a small office, and stairs and elevator for access to the second floor. • The foundation system should be completely embedded into competent unweathered terrace deposits or compacted fill. In general, unsuitable surficial soils are on the order of ±1 foot. However, localized deeper removals to mitigate potentially compressible soils cannot be precluded. The expansion potential of tested onsite soils is generally very low. Conventional foundations may likely be utilized for these soil conditions; however, based on field mapping in the vicinity of the site, the presence of numerous paleoliquefaction features ("sand blows," liquefaction craters, sand filled fissures and injection dikes, sand vents, etc.), may exist within the site. Potential liquefaction of such areas in the future that may impact surface Improvements is considered very low, provided thatthe recommendations presented in this report are incorporated into the design and construction of the project. Mitigation for structures may be provided by the use of post-tensioned slabs. Mitigation in other areas may be accomplished by overexcavation and/or geotextiles, as evaluated In the field durinq grading, based on proposed development and use. If paleoliquefaction features exist, post-tensioned foundations would be most suitable for this project. However, this recommendation would be based on conditions disclosed during grading. At the time of this report, corrosion testing results had not been received for the subject site. An addendum report, presenting those results, will be provided when lab testing is complete. In general, and based upon the available data to date, groundwater is not expected to be a major factor in development ofthe site; however, perched water may occur during construction and/or after site development, and should be anticipated. To mitigate the potential for water vapor problems owing to the possibility of perched water, the use of 4,500 psi concrete, with an altered water-cement ratio (0.45) is additionally recommended. Our evaluation indicates there are no known active faults crossing the site. The seismic acceleration values and design parameters provided herein should be considered during the design of the proposed development. Adverse geologic features that would preclude project feasibility were not encountered. The recommendations presented in this report should be incorporated into the design and construction considerations of the project. Salmen Insurance W.O. 4397-A-SC File:e:\wp9\4300\4397a.pge Page TwO GeoSoilSj Inc. The opportunity to be of service is greatly appreciated. If you have any questions concerning this report, or if we may be of further assistance, please do not hesitate to contact any of the undersigi Respectfully submitted, GeoSoils, Inc. Donna Gooley Engineering Geologist, RG fJohn P. Franklin Engineering Geologist, DG/JPF/DWS/jk/jh Distribution: (3) Addressee ^ David W.Ske Civil Engineer, RCE 47 Salmon Insurance File:e:\wp9\4300\4397a.pge W.O. 4397-A-SC Page Three G^oSoflSy Inc. TABLE OF CONTENTS SCOPE OF SERVICES 1 SITE CONDITIONS/PROPOSED DEVELOPMENT 1 FIELD STUDIES 1 REGIONAL GEOLOGY 3 EARTH MATERIALS 3 Topsoil/Colluvium 3 Terrace Deposits 3 MASS WASTING 4 FAULTING AND REGIONAL SEISMICITY 4 Faulting 4 Seismicity 4 Seismic Shaking Parameters 6 Seismic Hazards 7 GROUNDWATER 7 LIQUEFACTION POTENTIAL 8 LABORATORY TESTING 9 General 9 Moisture-Density Relations 9 Shear Testing 9 Expansion Potential 9 Corrosion Testing 10 PRELIMINARY CONCLUSIONS 10 EARTHWORK CONSTRUCTION RECOMMENDATIONS 10 General 10 Site Preparation 10 Removals (Unsuitable Surficial Materials) 11 Fill Placement 11 Transitions/Overexcavation 11 Subdrains 11 RECOMMENDATIONS - FOUNDATIONS 12 Preliminary Foundation Design 12 Bearing Value 12 Lateral Pressure 13 GeoSoilSf Ine. Foundation Settlement 13 Footing Setbacks 13 Construction 13 Very Low Expansion Potential (E.I. 0 to 20) 14 POST-TENSIONED SLAB SYSTEMS 15 Post-Tensioning Institute Method 15 UTILITIES 17 WALL DESIGN PARAMETERS 17 Conventional Retaining Walls 17 Restrained Walls 17 Cantilevered Walls 17 Retaining Wall Backfill and Drainage 18 Wall/Retaining Wall Footing Transitions 22 TOP-OF-SLOPE WALLS/FENCES/IMPROVEMENTS 22 Slope Creep 22 Top of Slope Walls/Fences 23 DRIVEWAY, FLATWORK, AND OTHER IMPROVEMENTS 24 DEVELOPMENT CRITERIA 26 Slope Deformation 26 Slope Maintenance and Planting 26 Drainage 27 Toe of Slope Drains/Toe Drains 27 Erosion Control 28 Landscape Maintenance 28 Gutters and Downspouts 31 Subsurface and Surface Water 31 Site Improvements 31 Tile Flooring 32 Additional Grading 32 Footing Trench Excavation 32 Trenching 32 Utility Trench Backfill 32 SUMMARYOF RECOMMENDATIONS REGARDING GEOTECHNICAL OBSERVATION AND TESTING 33 Salmen Insurance Table of Contents File:e:\wp9\4300\4397a.pge Page ii GeoSoils, Inc. OTHER DESIGN PROFESSIONALS/CONSULTANTS 34 PLAN REVIEW 34 LIMITATIONS 35 FIGURES: Figure 1 - Site Location Map 2 Figure 2 - California Fault Map 5 Detain - Typical Retaining Wal! Backflll and Drainage Detail 19 Detail 2 - Retaining Wall Backfill and Subdrain Detail Geotextile Drain 20 Detail 3 - Retaining Wall and Subdrain Detail Clean Sand Backfill 21 Detail 4 - Schematic Toe Drain Detail 29 Detail 5 - Subdrain Along Retaining Wall Detail 30 ATTACHMENTS: Appendix A - References Rear of Text Appendix B - Hand Auger Boring Logs Rear of Text Appendix 0 - EQFAULT. EQSEARCH. and FRISKSP Rear of Text Appendix D - General Earthwork and Grading Guidelines Rear of Text Plate 1 - Boring Location Map Rear of Text in Folder Salmen Insurance Table of Contents File:e:\wp9\4300\4397a.pge Page III GeoSoilSj Inc, PRELIMINARY GEOTECHNICAL EVALUATION 955 GRAND AVENUE CARLSBAD, SAN DIEGO COUNTY, CALIFORNIA SCOPE OF SERVICES The scope of our services has included the following: 1. Review of the available geologic literature for the site and vicinity (see Appendix A). 2. Subsurface exploration consisting of excavation of two exploratory hand auger borings for geotechnical logging and sampling (see Appendix B). 3. Laboratory testing of representative soil samples collected during our subsurface exploration program. 4. General areal seismicity evaluation (see Appendix C). 5. Appropriate engineering and geologic analysis of data collected and preparation of this report. SITE CONPrnONS/PROPOSED DEVELOPMENT The site consists of a rectangular lot located on the south side of Grand Avenue in the City of Carisbad, California (see Figure 1, Site Location Map). The site is surrounded on the remaining sides by residential property. Topographically, the site slopes very gently to the west and elevation at the site is approximately 75 feet Mean Sea Level (MSL). Drainage appears to be directed westward. Proposed site development is anticipated to consist of demolition ofthe existing one-story structure for construction of a two-story parking and business structure, as well as underground utility Improvements. It is anticipated that the planned building will use continuous footings and slab-on-grade floors, or post-tension foundations, with wood-frame and/or masonry block construction. Building loads are assumed to be typical for this type of relatively light structure. It is also our understanding that sewage disposal is proposed to be accommodated by tying into the regional municipal system. FIELD STUDIES Field studies conducted by GSI consisted of geologic mapping of the site, and the excavation of two exploratory hand auger borings for evaluation of near-surface soil and geologic conditions. The borings were logged by a geologist from our firm, who collected representative bulk and undisturbed samples from the borings for appropriate laboratory testing. The logs ofthe borings are presented in Appendix B. The locations ofthe borings are presented on Plate 1. GeoSoiUf Inc. Base Map: The Thomas Guide, San Diego County Street Guide and Directory, 2004 Edition by Thomas Bros. Maps, page 1106, 1"=1/2 mile ' 0 Scale 1/2 Miles ISI Rftproduotd with parmiasion arantsd by Thomas Bcos. Maps. This map la copyrightad by Thomas Broa. Maps. It is uniawfui to eopy or raproduca all or any part thereof, whether for personai usa or resale, without permission. All rights reserved. W.O. 4397-A-SC SITE LOCATION MAP Figure 1 REGIONAL GEOLOGY The subject property is located within a prominent natural geomorphic province in southwestern California known as the Peninsular Ranges. It is characterized by steep, elongated mountain ranges and valleys that trend northwesteriy. The mountain ranges are underlain by basement rocks consisting of pre-Cretaceous metasedimentary rocks, Jurassic metavolcanic rocks, and Cretaceous plutonic rocks of the southern California batholith. In the San Diego region, deposition occurred during the Cretaceous Period and Cenozoic Era in the continental margin of a forearc basin. Sediments, derived from Cretaceous-age plutonic rocks and Jurassic-age volcanic rocks, were deposited into the narrow, steep, coastal plain and continental margin ofthe basin. These rocks have been uplifted, eroded, and deeply incised. During early Pleistocene time, a broad coastal plain was developed from the deposition of marine and terrestrial terrace deposits. During mid to late Pleistocene time, this plain was uplifted, eroded, and incised. Alluvial deposits have since filled the lower valleys, and young marine sediments are currently being deposited/eroded within coastal and beach areas. The site is generally underlain by terrace deposits. EARTH MATERIALS Earth materials onsite consist of topsoil/colluvium and Pleistocene-age terrace deposits. A description of each material type is presented in the following discussion. Topsoil/Colluvium Topsoil/colluvium underlies the site to a depth of approximately 1 foot below existing ground surface. The topsoil/colluvial materials encountered onsite consist of light brown, silty sand. The materials generally were dry, loose, and porous. These materials are considered unsuitable forthe support of settlement-sensitive improvements in their existing state. Terrace Deposits Pleistocene-age terrace deposits underlie the site at shallow depth. Where encountered, these materials are typically orange brown, dry to moist, and medium dense to dense. Unweathered dense terrace deposits are considered suitable for structural support. Based on our site exploration, terrace deposits appear relatively massive. Elsewhere in the vicinity, It has been our experience that bedding structures within terrace deposits are relatively flat lying and therefore adverse bedding conditions are not anticipated. Salmen Insurance W.O. 4397-A-SC 955 Grand Avenue June 21, 2004 Flle:e:\wp9\4300\4397a.pge Page 3 GeoSoils, Inc. MASS WASTING No evidence of any significant pre-existing mass wasting features were indicated or observed during field exploration or during a review of available publications. FAULTING AND REGIONAL SEISMICITY Faulting The site is situated in a region of active as well as potentially-active faults. Our review indicates that there are no known active faults crossing the site within the areas proposed for development (Jennings, 1994), and the site is not within an Earthquake Fault Zone (Hart and Bryant, 1997). There are a number of faults in the southern California area that are considered active and would have an effect on the site in the form of ground shaking should they be the source of an earthquake. These faults include, but are not limited to: the San Andreas fault; the San Jacinto fault; the Elsinore fault; the Coronado Bank fault zone; and the Newport-Inglewood - Rose Canyon fault zone. The location of these, and other major faults relative to the site, are indicated on Figure 2 (California Fault Map). The possibility of ground acceleration or shaking at the site may be considered as approximately similar to the southern California region as a whole. The following table lists the major faults and fault zones in southern California that should have a significant effect on the site should they experience significant activity. ABBREVIATED FAULT NAME APPROXIMATE DISTANCE MILES (KM) Rose Canyon 5.4 (8.7) Newport-Inglewood-Offshore 5.4 (8.7) Coronado Bank-Agua Blanca 21.4 (34.4) Elsinore-Temecula 23.9 (38.4) San Jacinto-Anza 46.4 (74.7) Seismicitv The acceleration-attenuation relations of Sadigh, et al. (1997) Horizontal Soil, Bozorgnia. Campbell, and Niazi (1999) Horizontal-Soil-Correlation, and Campbell and Bozorgnia (1997 Rev.) Soft Rock have been incorporated into EQFAULT (Blake. 2000a). For this study, peak horizontal ground accelerations anticipated atthe site were determined based on the Salmen Insurance 955 Grand Avenue File:e:\wp9\4300\4397a.pge GeoSoils, Inc, W.O. 4397-A-SC June 21, 2004 Page 4 CALIFORNIA FAULT MAP Salmen 1100 1000 -- 900 -- 800 -- 700 600 -- 500 -100 400 300 -- 200 -- 100 -- -300 -200 100 200 300 400 500 600 W.O. 4397-A-SC Figure 2 GeoSoils, Ine. random mean plus 1 - sigma attenuation curve and mean attenuation curve developed by Joyner and Boore (1981, 1982a, 1982b, 1988, 1990), Bozorgnia, Campbell, and Niazi (1999), and Campbell and Bozorgnia (1997). EQFAULT is a computer program by Thomas F. Blake (2000a), which performs deterministic seismic hazard analyses using up to 150 digitized California faults as earthquake sources. The program estimates the closest distance between each fault and a given site. If a fault is found to be within a user-selected radius, the program estimates peak horizontal ground acceleration that may occur at the site from an upper bound ("maximum credible") earthquake on that fault. Site acceleration (g) is computed by one of many user-selected acceleration-attenuation relations that are contained in EQFAULT. Based on the EQFAULT program, peak horizontal ground accelerations from an upper bound event atthe site may be on the order of 0.55g to 0.63g. Historical site seismicity was evaluated with the acceleration-attenuation relations of Campbell and Bozorgnia (1997 Rev.) Soft Rock and the computer program EQSEARCH (Blake. 2000b). This program performs a search of the historical earthquake records for magnitude 5.0 to 9.0 seismic events within a 100-mile radius, between the years 1800 through December 2003. Based on the selected acceleration-attenuation relationship, a peak horizontal ground acceleration Is estimated, which may have effected the site during the specific event listed. Based on the available data and the attenuation relationship used, the estimated maximum (peak) site acceleration during the period 1800 through 2003 was 0.26g. Site specific probability of exceeding various peak horizontal ground accelerations and a seismic recurrence curve are also estimated/generated from the historical data. Computer printouts of pertinent portions of the EQSEARCH program are presented in Appendix 0. A probabilistic seismic hazards analyses was performed using FRISKSP (Blake, 2000c), which models earthquake sources as three-dimensional planes and evaluates the site specific probabilities of exceedance for given peak acceleration levels or pseudo-relative velocity levels. Based on a review of these data, and considering the relative seismic activity ofthe southern California region, a peak horizontal ground acceleration of 0.31 g was calculated. This value was chosen as it corresponds to a 10 percent probability of exceedance in 50 years (or a 475-year return period). Seismic Shaking Parameters Based on the site conditions, Chapter 16 of the Uniform Building Code ([UBC], International Conference of Building Officials [ICBO], 1997), the following seismic parameters are provided: Salmen Insurance W.O. 4397-A-SC 955 Grand Avenue June 21, 2004 File:e:\wp9\4300\4397a.pge Page 6 GeoSoils, Inc. Seismic zone (per Figure 16-2*) 4 Seismic Zone Factor (per Table 16-1*) 0.40 Soil Profile Type (per Table 16-J*) SD Seismic Coefficient C, (per Table 16-Q*) 0.44 N, Seismic Coefficient C^ (per Table 16-R*) 0.64 N, Near Source Factor (per Table 16-S*) 1.0 Near Source Factor N^ (per Table 16-T*) 1.05 Seismic Source Type (per Table 16-U*) B Distance to Seismic Source 5.4 mi (8.7 km) Upper Bound Earthquake (Rose Canyon) M« 6.9 * Figure and table references from Chapter 16 of the UBC (ICBO, 1997). Seismic Hazards The following list includes other seismic related hazards that have been considered during our evaluation ofthe site. The hazards listed are considered negligible and/or completely mitigated as a result of site location, soil characteristics, and typical site development procedures: • Tsunami • Dynamic Settlement • Surface Fault Rupture • Ground Lurching or Shallow Ground Rupture It is important to keep in perspective that in the event of a maximum probable or credible earthquake occurring on any of the nearby major faults, strong ground shaking would occur in the subject site's general area. Potential damage to any structure(s) would likely be greatest from the vibrations and impelling force caused by the inertia of a structure's mass than from those induced by the hazards considered above. This potential would be no greater than that for other existing structures and improvements in the immediate vicinity. GROUNDWATER Subsurface water was not encountered within the property during field work performed in preparation of this report. Subsurface water is not anticipated to adversely affect site development, provided thatthe recommendations contained in this report are incorporated into final design and construction. These observations reflect site conditions at the time Salmen Insurance 955 Grand Avenue File:e:\wp9\4300\4397a.pge W.O. 4397-A-SC June 21,2004 Page 7 GeoSoils, Inc. of our investigation and do not preclude future changes in local groundwater conditions from excessive irrigation, precipitation, or that were not obvious, at the time of our investigation. Regional groundwater is estimated to be at least 60 feet in depth, below the site. Seeps, springs, or other indications of a high groundwater level were not noted on the subject property during the time of our field investigation. However, seepage may occur locally (as the result of heavy precipitation or irrigation) in areas where any fill soils overiie terrace deposits or impermeable soils. Such conditions may occur during grading or after the site is developed, and should be anticipated. A sump pump may be required in any proposed below-grade parking. LIQUEFACTION POTENTIAL Seismically-induced liquefaction is a phenomenon in which cyclic stresses, produced by earthquake-induced ground motion, create excess pore pressures in soils. The soils may thereby acquire a high degree of mobility, and lead to lateral movement, sliding, sand boils, consolidation and settlement of loose sediments, and other damaging deformations. This phenomenon occurs only below the watertable; but after liquefaction has developed, it can propagate upward into overlying, non-saturated soil as excess pore water dissipates. Typically, liquefaction has a relatively low potential at depths greater than 45 feet and is virtually unknown below a depth of 60 feet. The condition of liquefaction has two principal effects. One is the consolidation of loose sediments with resultant settlement of the ground surface. The other effect is lateral sliding. Significant permanent lateral movement generally occurs only when there is significant differential loading, such as fill or natural ground slopes. No such loading conditions exist onsite. Liquefaction susceptibility is related to numerous factors and the following conditions should be concurrently present for liquefaction to occur: 1) sediments must be relatively young in age and not have developed a large amount of cementation; 2) sediments generally consist of medium to fine grained relatively cohesionless sands; 3) the sediments must have low relative density; 4) free groundwater must be present In the sediment; and, 5) the site must experience a seismic event of a sufficient duration and magnitude, to induce straining of soil particles. Since at least one ortwo ofthe five required concurrent conditions discussed above do not have the potential to affect the site, and evidence of paleoliquefaction features was not directly observed, our evaluation indicates thatthe potential for liquefaction and associated adverse effects within the site is low, even with a future rise in groundwater levels. The site conditions will also be improved by removal and recompaction of low density near-surface Salmen Insurance W.O. 4397-A-SC 955 Grand Avenue June 21, 2004 File:e:\wp9\4300\4397a.pge Page 8 GeoSoils, Inc. soils, and if evidence for paleoliquefaction is encountered during grading, the use of post-tension slabs. LABORATORY TESTING General Laboratory tests were performed on a representative sample ofthe onsite earth materials in order to evaluate their physical and engineering characteristics. The test procedures used and results obtained are presented below. Moisture-Densitv Relations The laboratory maximum dry density and optimum moisture content for representative site soils was determined according to test method ASTM D-1557. A maximum dry density of 128.0 pcf at an optimum moisture content of 9.5 percent was determined for a bulk composite sample obtained from the site. Field moisture and density determinations were also performed. The results of these determinations are presented on the Boring Logs in Appendix B. Shear Testina Shear testing was performed on a representative, remolded sample of site soil, in general accordance with ASTM Test Method D-3080, in a Direct Shear Machine ofthe strain control type. The shear test results are summarized below: SAMPLE LOCATION PRIMARY RESIDUAL . SAMPLE LOCATION COHESION (PSF) FRICTION ANGLE (DEGREES) COHESION (PSF) FRICTION ANGLE (DEGREES) B-1 @0-4feet 180 31 63 32 Expansion Potential Expansion testing was performed on a representative samples of site soil In accordance with UBC Standard 18-2. The results of expansion testing are presented in the following table. Salmen insurance 955 Grand Avenue File:e:\wp9\4300\4397a.pge GeoSoils, Inc. W.O. 4397-A-SC June 21,2004 Page 9 LOCATION EXPANSION INDEX EXPANSION POTENTIAL B-1 (S 0 - 4 feet 0 Very Low Corrosion Testing Laboratory test results for soluble sulfates. pH. and corrosion to metals have not been received as of the date of this report. Testing will be presented as an addendum upon receipt ofthe results. Additional testing of site materials is recommended when proposed grading is complete, to further evaluate the findings. PRELIMINARY CONCLUSIONS Based upon our site reconnaissance test results, it is our opinion that the subject site appears suitable forthe proposed business development. The following recommendations should be Incorporated Into the construction details. EARTHWORK CONSTRUCTION RECOMMENDATIONS General All grading should conform to the guidelines presented in Appendix Chapter A33 of the UBC, the requirements ofthe City, and the Grading Guidelines presented In Appendix D, except where specifically superceded in the text of this report. Prior to grading, a GSI representative should be present at the preconstruction meeting to provide additional grading guidelines, if needed, and review the earthwork schedule. During earthwork construction, all site preparation and the general grading procedures of the contractor should be observed and the fill selectively tested by a representative(s) of GSI. If unusual or unexpected conditions are exposed in the field, they should be reviewed by this office and, if warranted, modified and/or additional recommendations will be offered. All applicable requirements of local and national construction and general industry safety orders, the Occupational Safety and Health Act, and the Construction Safety Act should be met. Site Preparation Debris, vegetation, existing structures, and other deleterious material should be removed from the building area prior to the start of construction. Sloping areas to receive fill should be properiy benched in accordance with current industry standards of practice and guidelines specified in the UBC. Salmen Insurance W.O. 4397-A-SC 955 Grand Avenue June 21, 2004 File:e:\wp9\4300\4397a.pge Page 10 GeoSoils, Inc. Removals (Unsuitable Surficial Materials) Due to the relatively loose condition of topsoil and weathered terrace deposits, these materials should be removed and recompacted in areas proposed for settlement-sensitive structures or areas to receive compacted fill. At this time, removal depths on the order of 1 foot (including topsoil and weathered terrace deposits) below existing grade should be anticipated throughout a majority ofthe site; however, locally deeper removals cannot be precluded. Due to the relatively loose and porous condition ofthe topsoil/colluvial, these materials should be removed, moisture conditioned, and recompacted and/or processed in place. Removals should be completed below a 1:1 projection down and away from the edge of any settlement-sensitive improvements and/or limits of proposed fill. Once removals are completed, the exposed bottom should be reprocessed and compacted to 90 percent relative compaction. Fiil Placement Subsequent to ground preparation, onsite soils may be placed in thin (±6-inch) lifts, cleaned of vegetation and debris, brought to a least optimum moisture content, and compacted to achieve a minimum relative compaction of 90 percent. If soil importation is planned, a sample ofthe soil import should be evaluated by this office prior to importing, in order to assure compatibility with the onsite site soils and the recommendations presented in this report. Import soils for a fill cap should be very low expansive (Expansion Index [E.I.] less than 20). The use of subdrains at the bottom of the fill cap may be necessary, and subsequently recommended based on compatibility with onsite soils and proximity and/or suitability of an outlet. Transitions/Overexcavation Cut portions of cut/fill transition pads should be overexcavated a minimum 3 feet below pad grade. Areas with planned fills less than 3 feet should be overexcavated in order to provide a minimum fill thickness of 3 feet, or 2 feet below the foundation, whichever is greater. Where the ratio of maximum to minimum fill thickness below a given structure exceeds 3:1, overexcavation should be completed to reduce this ratio to 3:1. or less. Subdrains In general, and based upon the available data to date, groundwater is not anticipated to be a factor In development of the site. However, due to the nature of the site materials, seepage may be encountered throughout the site, along with seasonal perched water within any drainage areas. Seepage may also be encountered in "daylighted" joint systems within the terrace deposits. Thus, subdrain systems are recommended within shallow groundwater areas. In addition, subdrainage systems for the control of localized groundwater seepage should be anticipated, should such conditions develop during or Salmen Insurance W.O. 4397-A-SC 955 Grand Avenue June 21, 2004 File:e:\wp9\4300\4397a.pge Page 11 GeoSoils, Inc. after grading. Should such conditions develop, this office should be contacted for mitigative recommendations. Local seepage along the contact between the bedrock and overburden materials, or along jointing patterns ofthe bedrock, will likely require a subdrain system. Where removals are below the subdrain fiowline. the removal materials may be reused as compacted fill provided they are granular, and at a moisture content of at least 2 percent over optimum moisture content (or 1.2 times optimum moisture content, whichever is greater). RECOMMENDATIONS - FOUNDATIONS Preliminarv Foundation Design In the event that the information concerning the proposed development plans are not correct, or any changes in the design, location, or loading conditions of the proposed structures are made, the conclusions and recommendations contained in this report are forthe subject site only and shall not be considered valid unless the changes are reviewed and conclusions of this report are modified or approved in writing by this office. The information and recommendations presented in this section are considered minimums and are not meant to supercede design(s) by the project structural engineer or civil engineer specializing in structural design. Upon request. GSI could provide additional consultation regarding soil parameters, as related to foundation design. They are considered preliminary recommendations for proposed construction, in consideration of our field investigation, and laboratory testing and engineering analysis. Our review, field work, and recent and previous laboratory testing indicates that onsite soils have a very low expansion potential range (E.I. 0 to 20). Preliminary recommendations for foundation design and construction are presented below. Final foundation recommendations should be provided atthe conclusion of grading based on laboratory testing of fill materials exposed at finish grade. Bearing Value 1. The foundation systems should be designed and constructed in accordance with guidelines presented in the latest edition of the UBC. 2. An allowable bearing value of 1,500 pounds per square foot (psf) may be used for design of continuous footings 12 inches wide and 12 inches deep and for design of isolated pad footings 24 Inches square and 18 inches deep founded entirely Into compacted fill or competent formational material and connected by grade beam or tie beam in at least one direction. This value may be increased by 20 percent for Salmon insuranco W.O. 4397-A-SC 955 Grand Avenue June 21, 2004 File:e:\wp9\4300\4397a.pge Page 12 GeoSoils, Inc. each additional 12 inches in depth to a maximum value of 2,500 psf. The above values may be increased by one-third when considering short duration seismic or wind loads. No increase in bearing for footing width is recommended. Lateral Pressure 1. For lateral sliding resistance, a 0.35 coefficient of friction may be utilized for a concrete to soil contact when multiplied bythe dead load. 2. Passive earth pressure may be computed as an equivalent fluid having a density of 250 pounds per cubic foot (pcf). with a maximum earth pressure of 2.500 psf. 3. When combining passive pressure and frictional resistance, the passive pressure component should be reduced by one-third. Foundation Settlement Foundations systems should be designed to accommodate a worst case differential settlement of 1 inch in a 40-foot span. Footinq Setbacks All footings should maintain a minimum 7-foot horizontal setback from the base of the footing to any descending slope. This distance is measured from the footing face at the bearing elevation. Footings should maintain a minimum horizontal setback of H/3 (H=slope height) from the base ofthe footing to the descending slope face, and no less than 7 feet nor need to be greater than 40 feet. Footings adjacent to unlined drainage swales should be deepened to a minimum of 6 inches below the invert of the adjacent unlined swale. Footings for structures adjacent to retaining walls should be deepened so as to extend below a 1:1 projection from the heel of the wall. Alternatively, walls may be designed to accommodate structural loads from buildings or appurtenances as described in the Retaining Wall section ofthis report. Construction The following foundation construction recommendations are presented as a minimum criteria from a soils engineering standpoint. The onsite soils expansion potentials are generally very low (E.I. 0 to 20). Recommendations for very low expansive soil conditions are presented herein. Recommendations by the project's design-structural engineer or architect, which may exceed the soils engineer's recommendations, should take precedence over the following minimum requirements. Final foundation design will be provided based on the expansion potential of the near surface soils encountered during grading. Salmon insurance W.O. 4397-A-SC 955 Grand Avenue June 21, 2004 File:e:\wp9\4300\4397a.pge Page 13 GeoSoils, Inc. Very Low Expansion Potential (E.I. 0 to 20) 1. Exterior and interior footings should be founded at a minimum depth of 12 inches for one-story floor loads, 18 inches for two-story floor loads, and 24 inches for three-story floor loads below the lowest adjacent ground surface. Isolated column and panel pads, or wall footings, should be founded at a minimum depth of 24 inches. All footings should be reinforced with two No. 4 reinforcing bars, one placed near the top and one placed near the bottom ofthe footing. Footing widths should be as indicated in the UBC (ICBO. 1997); width of 12 inches for one-story loads, 15 inches for two-story loads, and 18 Inches for three-story loads. 2. A grade beam, reinforced as above, and at least 12 inches wide should be provided across large (e.g., doorways) entrances. The base ofthe grade beam should be at the same elevation as the bottom of adjoining footings. Isolated, exterior square footings should be tied within the main foundation in at least one direction with a grade beam. 3. Residential concrete slabs, where moisture condensation is undesirable, including garage slabs, should be underiain with a vapor barrier consisting of a minimum of 10 mil polyvinyl chloride or equivalent membrane with all laps sealed per the UBC/CBC. This membrane should be covered above and below with a minimum of 2 inches of sand (total of 4 inches) to aid in uniform curing of the concrete and to protect the membrane from puncture. 4. To further mitigate the potential for water vapor problems owing to the possibility of perched water, the use of 4,500 psi concrete, with an altered water-cement ratio (0.45) is additionally recommended. 5. Residential and garage concrete slabs should be a minimum of 5 inches thick, and should be reinforced with No. 3 reinforcing bar at 18 inches on center in both directions. All slab reinforcement should be supported to ensure placement near the vertical midpoint ofthe concrete. "Hooking" of reinforcement is not considered an acceptable method of positioning the reinforcement. 6. Garage slabs should be a minimum of 5 inches thick and should be reinforced as above and poured separately from the structural footings and quartered with expansion joints or saw cuts. A positive separation from the footings should be maintained with expansion joint material to permit relative movement. 7. Specific presaturation is not required for these soil conditions; however, GSI recommends that the moisture content ofthe subgrade soils should be equal to or greater than optimum moisture content to a depth of 12 inches in the slab areas prior to the placement of visqueen. Salmon Insuranco W.O. 4397-A-SC 955 Grand Avenue June 21, 2004 File:e:\wp9\4300\4397a.pge Page 14 GeoSoils, Inc. POST-TENSIONED SLAB SYSTEMS Post-tension foundations are specifically recommended if paleoliquefaction features ("sand blows," liquefaction craters, sand filled fissures and injection dikes, sand vents, etc.) are encountered during grading. The recommendations presented below should be followed in addition to those contained in the previous sections, as appropriate. The information and recommendations presented below in this section are not meant to supercede design by a registered structural engineer or civil engineer familiar with post-tensioned slab design. Post-tensioned slabs should be designed using sound engineering practice and be in accordance with local and/or national code requirements. Upon request, GSI can provide additional data/consultation regarding soil parameters as related to post-tensioned slab design. From a soil expansion/shrinkage standpoint, a common contributing factor to distress of structures using post-tensioned slabs Is fluctuation of moisture in soils underlying the perimeter ofthe slab, compared to the center, causing a "dishing" or "arching" ofthe slabs. To mitigate this possibility, a combination of soil presaturation and construction of a perimeter cut off wall should be employed. To further mitigate the potential for water vapor problems owing to the possibility of perched water, the use of 4,500 psi concrete, with an altered water-cement ratio (0.45) is additionally recommended. Perimeter cut-off walls should be a minimum of (18 inches deep for medium expansive soils. The cut-off walls may be integrated into the slab design or independent ofthe slab. The concrete slab should be a minimum of 6 inches thick. Slab underfayment should consist of 4 inches of washed sand with a vapor barrier consisting of 10-mil polyvinyl chloride or equivalent placed mid-depth within the sand. Post-Tensioning Institute Method Post-tensioned slabs should have sufficient stiffness to resist excessive bending due to non-uniform swell and shrinkage of subgrade soils. The differential movement can occur at the corner, edge, or center of the slab. The potential for differential uplift can be evaluated using the 1997 UBC, Section 1816, based on design specifications of the Post-Tensioning Institute. The following table presents suggested minimum coefficients to be used in the Post-Tensioning Institute design method. Salmon Insuranco W.O. 4397-A-SC 955 Grand Avenue June 21, 2004 File:e:\wp9\4300\4397a.pge Page 15 GeoSoils, Inc. Thornthwaite Moisture Index -20 inches/year Correction Factor for Irrigation 20 inches/year Depth to Constant Soil Suction 7 feet Constant soil Suction (pf) 3.6 Modulus of Subgrade Reaction (pci) 75 Moisture Velocity 0.7 inches/month The coefficients are considered minimums and may not be adequate to represent worst case conditions such as adverse drainage and/or improper landscaping and maintenance. The above parameters are applicable provided structures have positive drainage that is maintained away from structures. Therefore, it is important that information regarding drainage, site maintenance, settlements, and effects of expansive soils be passed on to future owners. Based on the above parameters, the following values were obtained from figures or tables ofthe 1997 UBC Section, 1816. The values may not be appropriate to account for possible differential settlement of the slab due to other factors. If a stiffer slab is desired, higher values of ym may be warranted. EXPANSION INDEX OF SOIL SUBGRADE VERY LOW EXPANSION (E.I. = 0-20) e^ center lift 5.0 feet e^ edge lift 2.5 feet y^, center lift 1.0 inch y^ edge lift 0.3 inch Deepened footings/edges around the slab perimeter must be used to minimize non-uniform surface moisture migration (from an outside source) beneath the slab. An edge depth of 12 inches should be considered a minimum. The bottom ofthe deepened footing/edge should be designed to resist tension, using cable or reinforcement per the structural engineer. Other applicable recommendations presented under conventional foundation and the California Foundation Slab Method should be adhered to during the design and construction phase of the project. Salmon Insuranco 955 Grand Avenue File: e:\wp9\4300\4397a.pge W.O. 4397-A-SC June 21,2004 Page 16 GeoSoils, Inc. UTILITIES Utilities should be enclosed within a closed utilidor (vault) or designed with flexible connections to accommodate differential settlement and any potentially expansive soil conditions. Due to the potential for differential settlement, air conditioning (NC) units should be supported by slabs that are incorporated into the building foundation or constructed on a rigid slab with flexible couplings for plumbing and electrical lines. A/C waste waterlines should be drained to a suitable outlet. WALL DESIGN PARAMETERS Conventional Retaining Walls The design parameters provided below assume that either non expansive soils (Class 2 permeable filter material or Class 3 aggregate base) or native materials (up to and including an E.I. of 65) are used to backfill any retaining walls. The type of backfill (i.e., select or native), should be specified by the wall designer, and clearly shown on the plans. Building walls, below grade, should be water-proofed or damp-proofed, depending on the degree of moisture protection desired. The foundation system for the proposed retaining walls should be designed in accordance with the recommendations presented in this and preceding sections of this report, as appropriate. Footings should be embedded a minimum of 18 inches below adjacent grade (excluding landscape layer, 6 inches) and should be 24 inches in width. There should be no increase in bearing for footing width. Recommendations for specialty walls (i.e., crib, earthstone. geogrid, etc.) can be provided upon request, and would be based on site specific conditions. Restrained Walls Any retaining walls that will be restrained priorto placing and compacting backfill material or that have re-entrant or male corners, should be designed for an at-rest equivalent fluid pressure (EFP) of 65 pcf, plus any applicable surcharge loading. For areas of male or re-entrant corners, the restrained wall design should extend a minimum distance of twice the height of the wall (2H) laterally from the corner. Cantilevered Walls The recommendations presented below are for cantilevered retaining walls up to 10 feet high. Design parameters for walls less than 3 feet in height may be superseded by City and/or County standard design. Active earth pressure may be used for retaining wall design, provided the top ofthe wall is not restrained from minor deflections. An equivalent fluid pressure approach may be used to compute the horizontal pressure against the wall. Appropriate fluid unit weights are given below for specific slope gradients of the retained material. These do not include other superimposed loading conditions due to traffic, Salmon insuranco W.O. 4397-A-SC 955 Grand Avenue June 21, 2004 File:e:\wp9\4300\4397a.pge Page 17 GeoSoils, Inc. structures, seismic events or adverse geologic conditions. When wall configurations are finalized, the appropriate loading conditions for superimposed loads can be provided upon request. SURFACE SLOPE OF RETAINED MATERIAL (HORIZONTALVERTICAL) EQUIVALENT FLUID WEIGHT P.C.F. (SELECT BACKFILL)^ EQUIVALENT FLUID WEIGHT P.C.F. (NATIVE BACKFILL) Level* 2 tol 35 50 45 60 * Level backfill behind a retaining wall is defined as compacted earth materials, properly drained, without a slope for a distance of 2H behind the wall. Retaining Wall Backfill and Drainage Positive drainage must be provided behind all retaining walls In the form of gravel wrapped in geofabric and outlets. A backdrain system is considered necessary for retaining walls that are 2 feet or greater In height. Details 1.2, and 3, present the back drainage options discussed below. Backdrains should consist of a 4-inch diameter perforated PVC or ABS pipe encased in either Class 2 permeable filter material or y2-inch to y4-inch gravel wrapped in approved filter fabric (Mirafi 140 or equivalent). For low expansive backfill, the filter material should extend a minimum of 1 horizontal foot behind the base of the walls and upward at least 1 foot. For native backfill that has up to medium expansion potential, continuous Class 2 permeable drain materials should be used behind the wall. This material should be continuous (i.e.. full height) behind the wall, and It should be constructed in accordance with the enclosed Detail 1 (Typical Retaining Wall Backfill and Drainage Detail). For limited access and confined areas, (panel) drainage behind the wall may be constructed in accordance with Detail 2 (Retaining Wall Backfill and Subdrain Detail Geotextile Drain). Materials with an E.I. potential of greater than 65 should not be used as backfill for retaining walls. For more onerous expansive situations, backfill and drainage behind the retaining wall should conform with Detail 3 (Retaining Wall And Subdrain Detail Clean Sand Backfill). Outlets should consist of a 4-inch diameter solid PVC or ABS pipe spaced no greater than ±100 feet apart, with a minimum of two outlets, one on each end. The use of weep holes in walls higher than 2 feet should not be considered. The surface ofthe backfill should be sealed by pavement or the top 18 inches compacted with native soil (E.I. <.90). Proper surface drainage should also be provided. For additional mitigation, consideration should be given to applying a water-proof membrane to the back of all retaining structures. The use of a waterstop should be considered for all concrete and masonry joints. Salmon insuranco 955 Grand Avenue File:e:\wp9\4300\4397a.pge W.O. 4397-A-SC June 21,2004 Page 18 GeoSoils, Inc. DETAILS N.T.S. Provide Surface Drainage (Dwaterproofing Membrane (optional) (D Weep Hole Finished Surface (D WATERPROOFING MEMBRANE (optional): Liquid boot or approved equivalent. (D ROCK: 3/4 to 1-1/2" (inches) rock. ® FILTER FABRIC: Mirafi 140N or approved equivalent; place fabric flap behind core. ® PIPE: 4" (inches) diameter perforated PVC. schedule 40 or approved alternative with minimum of 1% gradient to proper outlet point. (D WEEP HOLE: Minimum 2" (inches) diameter placed at 20' (feet) on centers along the wall, and 3" (inches) above finished surface. (No weep holes for basement walls.) TYPICAL RETAINING WALL BACKFILL AND DRAINAGE DETAIL DETAIL 1 Geotechnical • Geologic • Environmental DETAILS N.T.S. Provide Surface Drainage (Dwaterproofing Membrane (optional) Weep Hole Finished Surface 1 or Flatter <3) WATERPROOFING MEMBRANE (optional): Liquid boot or approved equivalent. (D DRAIN: Miradrain 6000 or J-drain 200 or equivalent for non-waterproofed walls. Miradrain 6200 or J-draln 200 or equivalent for waterproofed walls. ® FILTER FABRIC: Mirafi 140N or approved equivalent; place fabric flap behind care. ® PIPE: 4" (inches) diameter perforated PVC. schedule 40 or approved alternative with minimum of 1% gradient to proper outlet point. (D WEEP HOLE: Minimum 2" (Inches) diameter placed at 20' (feet) on centers along the wall, and 3" (inches) above finished surface. (No weep holes for basement walls.) RETAINING WALL BACKFILL AND SUBDRAIN DETAIL GEOTEXTILE DRAIN DETAIL 2 Geotechnical • Geologic • Environmental DETAILS N.T.S. Provide Surface Drainage (D Clean Sand Backfill ® WATERPROOFING MEMBRANE (optional): Liquid boot or approved equivalent. (D CLEAN SAND BACKFILL: Must have sand dequivalent value of 30 or greater; can be densified by water jetting. (D FILTER FABRIC: Mirafi 140N or approved equivalent. ® ROCK: 1 cubic foot per linear feet of pipe or 3/4 to 1-1/2" (Inches) rock. (D PIPE: 4" (Inches) diameter perforated PVC. schedule 40 or approved alternative with minimum of 1% gradient to proper outlet point. ® WEEP HOLE: Minimum 2" (inches) diameter placed at 20' (feet) on centers along the wall, and 3" (inches) above finished surface. (No weep holes for basement walls.) RETAINING WALL AND SUBDRAIN DETAIL CLEAN SAND BACKFILL DETAIL 3 Geotechnical • Geologic • Environmental Wall/Retaining Wail Footing Transitions Site walls are anticipated to be founded on footings designed in accordance with the recommendations in this report. Should wall footings transition from cut to fill, the civil designer may specify either: a) A minimum of a 2-foot overexcavation and recompaction of cut materials for a distance of 2H, from the point of transition. b) Increase of the amount of reinforcing steel and wall detailing (i.e., expansion joints or crack control joints) such that a angular distortion of 1/360 for a distance of 2H on either side of the transition may be accommodated. Expansion joints should be sealed with a flexible, non-shrink grout. c) Embed the footings entirely into native formational material (i.e., deepened footings). If transitions from cut to fill transect the wall footing alignment at an angle of less than 45 degrees (plan view), then the designer should follow recommendation "a" (above) and until such transition is between 45 and 90 degrees to the wall alignment. TOP-OF-SLOPE WALLS/FENCES/IMPROVEMENTS Slope Creep Soils at the site may be expansive and therefore, may become desiccated when allowed to drv. Such soils are susceptible to surficial slope creep, especially with seasonal changes In moisture content. Typically In southern California, during the hot and dry summer period, these soils become desiccated and shrink, thereby developing surface cracks. The extent and depth of these shrinkage cracks depend on many factors such as the nature and expansivity of the soils, temperature and humidity, and extraction of moisture from surface soils by plants and roots. When seasonal rains occur, water percolates into the cracks and fissures, causing slope surfaces to expand, with a corresponding loss in soil density and shear strength near the slope surface. With the passage of time and several moisture cycles, the outer 3 to 5 feet of slope materials experience a very slow, but progressive, outward and downward movement, known as slope creep. For slope heights greater than 10 feet, this creep related soil movement will typically Impact all rear yard flatwork and other secondary Improvements that are located within about 15 feet from the top of slopes, such as swimming pools, concrete flatwork. etc., and in particular top of slope fences/walls. This influence is normally In the form of detrimental settlement, and tilting ofthe proposed improvements. The dessication/swelling and creep discussed above continues over the life of the improvements, and generally Salmon Insuranco W.O. 4397-A-SC 955 Grand Avenue June 21, 2004 File:e:\wp9\4300\4397a.pge Page 22 GeoSoils, Inc. becomes progressively worse. Accordingly, the developer should provide this information to any homeowners and homeowners association. Top of Slope Walls/Fences Due to the potential for slope creep for slopes higher than about 10 feet, some settlement and tilting ofthe walls/fence with the corresponding distresses, should be expected. To mitigate the tilting of top of slope walls/fences, we recommend that the walls/fences be constructed on deepened foundations without any consideration for creep forces, where the E.I. of the materials comprising the outer 15 feet of the slope is less than 50, or a combination of grade beam and caisson foundations, for expansion indices greater than 50 comprising the slope, with creep forces taken into account The grade beam should be at a minimum of 12 inches by 12 inches in cross section, supported by drilled caissons, 12 inches minimum in diameter, placed ata maximum spacing of 6feet on center, and with a minimum embedment length of 7 feet below the bottom ofthe grade beam. The strength ofthe concrete and grout should be evaluated by the structural engineer of record. The proper ASTM tests for the concrete and mortar should be provided along with the slump quantities. The concrete used should be appropriate to mitigate sulfate corrosion, as warranted. The design of the grade beam and caissons should be in accordance with the recommendations of the project structural engineer, and include the utiiizatlon of the following geotechnical parameters: Creep Zone: 5-foot vertical zone below the slope face and projected upward parallel to the slope face. Creep Load: The creep load projected on the area of the grade beam should be taken as an equivalent fluid approach, having a density of 60 pcf. For the caisson, it should be taken as a uniform 900 pounds per linear foot of caisson's depth, located above the creep zone. Point of Fixitv: Passive Resistance: Located a distance of 1.5 times the caisson's diameter, below the creep zone. Passive earth pressure of 300 psf per foot of depth per foot of caisson diameter, to a maximum value of 4.500 psf may be used to determine caisson depth and spacing, provided that they meet or exceed the minimum requirements stated above. To determine the total lateral resistance, the contribution ofthe creep prone zone above the point of fixity, to passive resistance, should be disregarded. Salmon Insuranco 955 Grand Avenue File:e:\wp9\4300\4397a.pge W.O. 4397-A-SC June 21,2004 Page 23 GeoSoils, Inc. Allowable Axial Capacitv: Shaft capacity : 350 psf applied below the point of fixity over the surface area of the shaft. Tip capacity: 4,500 psf. DRIVEWAY. FLATWORK. AND OTHER IMPROVEMENTS The soil materials on site may be expansive. The effects of expansive soils are cumulative, and typically occur over the lifetime of any improvements. On relatively level areas, when the soils are allowed to dry, the dessication and swelling process tends to cause heaving and distress to flatwork and other improvements. The resulting potential for distress to improvements may be reduced, but not totally eliminated. To that end, it is recommended that the developer should notify any homeowners or homeowners association ofthis long- term potential for distress. To reduce the likelihood of distress, the following recommendations are presented for all exterior flatwork: 1. The subgrade area for concrete slabs should be compacted to achieve a minimum 90 percent relative compaction, and then be presoaked to 2 to 3 percentage points above (or 125 percent of) the soils' optimum moisture content, to a depth of 18 Inches below subgrade elevation. If very low expansive soils are present, only optimum moisture content, or greater, is required and specific presoaking is not warranted. The moisture content of the subgrade should be verified within 72 hours prior to pouring concrete. 2. Concrete slabs should be cast over a non-yielding surface, consisting of a 4-inch layer of crushed rock, gravel, or clean sand, that should be compacted and level prior to pouring concrete. If very low expansive soils are present, the rock or gravel or sand may be deleted. The layer or subgrade should be wet-down completely prior to pouring concrete, to minimize loss of concrete moisture to the surrounding earth materials. 3. Exterior slabs should be a minimum of 4 inches thick. Driveway slabs and approaches should additionally have a thickened edge (12 inches) adjacent to all landscape areas, to help impede infiltration of landscape water under the slab. 4. The use of transverse and longitudinal control joints are recommended to help control slab cracking due to concrete shrinkage or expansion. Two ways to mitigate such cracking are: a) add a sufficient amount of reinforcing steel, increasing tensile strength of the slab; and, b) provide an adequate amount of control and/or expansion joints to accommodate anticipated concrete shrinkage and expansion. Salmon insurance W.O. 4397-A-SC 955 Grand Avenue June 21, 2004 Flle:e:\wp9\4300\4397a.pge Page 24 GeoSoils, Inc. In order to reduce the potential for unsightly cracks, slabs should be reinforced at mid-height with a minimum of No. 3 bars placed at 18 inches on center, in each direction. The exterior slabs should be scored or saw cut, Vz to % inches deep, often enough so that no section is greater than 10 feet by 10 feet. For sidewalks or narrow slabs, control joints should be provided at intervals of every 6 feet. The slabs should be separated from the foundations and sidewalks with expansion joint filler material. 5. No traffic should be allowed upon the newly poured concrete slabs until they have been properiy cured to within 75 percent of design strength. Concrete compression strength should be a minimum of 2,500 psi. 6. Driveways, sidewalks, and patio slabs adjacent to the house should be separated from the house with thick expansion joint filler material. In areas directly adjacent to a continuous source of moisture (i.e., irrigation, planters, etc.), all joints should be additionally sealed with flexible mastic. 7. Planters and walls should not be tied to the house. 8. Overhang structures should be supported on the slabs, or structurally designed with continuous footings tied in at least two directions. If very low expansion soils are present, footings need only be tied in one direction. 9. Any masonry landscape walls that are to be constructed throughout the property should be grouted and articulated in segments no more than 20 feet long. These segments should be keyed or doweled together. 10. Utilities should be enclosed within a closed utilidor (vault) or designed with flexible connections to accommodate differential settlement and expansive soil conditions. 11. Positive site drainage should be maintained at all times. Finish grade on the lots should provide a minimum of 1 to 2 percent fall to the street, as indicated herein. It should be kept In mind that drainage reversals could occur, including post-construction settlement, if relatively flat yard drainage gradients are not periodically maintained by the homeowner or homeowners association. 12. Air conditioning (A/C) units should be supported by slabs that are incorporated into the building foundation or constructed on a rigid slab with flexible couplings for plumbing and electrical lines. NC waste water lines should be drained to a suitable non-erosive outlet. 13. Shrinkage cracks could become excessive if proper finishing and curing practices are not followed. Finishing and curing practices should be performed per the Portland Cement Association Guidelines. Mix design should incorporate rate of Salmon Insurance W.O. 4397-A-SC 955 Grand Avenue June 21, 2004 File:e:\wp9\4300\4397a.pge Page 25 GeoSoils, Inc. curing for climate and time of year, sulfate content of soils, corrosion potential of soils, and fertilizers used on site. DEVELOPMENT CRITERIA Slope Deformation Compacted fill slopes designed using customary factors of safety for gross or surficial stability and constructed in general accordance with the design specifications should be expected to undergo some differential vertical heave or settlement in combination with differential lateral movement in the out-of-slope direction, after grading. This post-construction movement occurs in two forms: slope creep, and lateral fill extension (LFE). Slope creep is caused by alternate wetting and drying of the fill soils which results in slow downslope movement. This type of movement is expected to occur throughout the life of the slope, and is anticipated to potentially affect improvements or structures (i.e., separations and/or cracking), placed near the top-of-slope, up to a maximum distance of approximately 15 feet from the top-of-slope, depending on the slope height. This movement generally results in rotation and differential settlement of improvements located within the creep zone. LFE occurs due to deep wetting from irrigation and rainfall on slopes comprised of expansive materials. Although some movement should be expected, long-term movement from this source may be minimized, but not eliminated, by placing the fill throughout the slope region, wet ofthe fill's optimum moisture content. It is generally not practical to attempt to eliminate the effects of either slope creep or LFE. Suitable mitigative measures to reduce the potential of lateral deformation typically include: setback of improvements from the slope faces (per the 1997 UBC and/or California Building Code), positive structural separations (I.e., joints) between improvements, and stiffening and deepening of foundations. All of these measures are recommended for design of structures and improvements. The ramifications of the above conditions, and recommendations for mitigation, should be provided to each homeowner and/or any homeowners association. Slope Maintenance and Planting Water has been shown to weaken the Inherent strength of all earth materials. Slope stability is significantly reduced by overly wet conditions. Positive surface drainage away from slopes should be maintained and only the amount of irrigation necessary to sustain plant life should be provided for planted slopes. Over-watering should be avoided as It can adversely affect site improvements, and cause perched groundwater conditions. Graded slopes constructed utilizing onsite materials would be erosive. Eroded debris may be minimized and surficial slope stability enhanced by establishing and maintaining a suitable vegetation cover soon after construction. Compaction to the face of fill slopes would tend to minimize short-term erosion until vegetation is established. Plants selected for Salmon Insuranco W.O. 4397-A-SG 955 Grand Avenue June 21, 2004 File:e:\wp9\4300\4397a.pge Page 26 GeoSoils, Inc. landscaping should be light weight, deep rooted types that require little water and are capable of surviving the prevailing climate. Jute-type matting or other fibrous covers may aid in allowing the establishment of a sparse plant cover. Utilizing plants other than those recommended above will increase the potential for perched water, staining, mold, etc., to develop. A rodent control program to prevent burrowing should be implemented. Irrigation of natural (ungraded) slope areas Is generally not recommended. These recommendations regarding plant type, Irrigation practices, and rodent control should be provided to each homeowner. Over-steepening of slopes should be avoided during building construction activities and landscaping. Drainage Adequate lot surface drainage is a very important factor in reducing the likelihood of adverse performance of foundations, hardscape, and slopes. Surface drainage should be sufficient to prevent ponding of water anywhere on a lot, and especially near structures and tops of slopes. Lot surface drainage should be carefully taken into consideration during fine grading, landscaping, and building construction. Therefore, care should be taken that future landscaping or construction activities do not create adverse drainage conditions. Positive site drainage within lots and common areas should be provided and maintained at all times. Drainage should not flow uncontrolled down any descending slope. Water should be directed away from foundations and not allowed to pond and/or seep into the ground. In general, the area within 5 feet around a structure should slope away from the structure. We recommend that unpaved lawn and landscape areas have a minimum gradient of 1 percent sloping away from structures, and whenever possible, should be above adjacent paved areas. Consideration should be given to avoiding construction of planters adjacent to structures (buildings, pools, spas, etc.). Pad drainage should be directed toward the street or other approved area(s). Although not a geotechnical requirement, roof gutters, down spouts, or other appropriate means may be utilized to control roof drainage. Down spouts, or drainage devices should outlet a minimum of 5 feet from structures or into a subsurface drainage system. Areas of seepage may develop due to irrigation or heavy rainfall, and should be anticipated. Minimizing irrigation will lessen this potential. If areas of seepage develop, recommendations for minimizing this effect could be provided upon request. Toe of Slope Drains/Toe Drains Where significant slopes intersect pad areas, surface drainage down the slope allows for some seepage into the subsurface materials, sometimes creating conditions causing or contributing to perched and/or ponded water. Toe of slope/toe drains may be beneficial in the mitigation of this condition due to surface drainage. The general criteria to be utilized by the design engineer for evaluating the need for this type of drain is as follows: • Is there a source of irrigation above or on the slope that could contribute to saturation of soil at the base of the slope? Salmon Insuranco W.O. 4397-A-SC 955 Grand Avenue June 21, 2004 File:e:\wp9\4300\4397a.pge Page 27 GeoSoils, Inc. • Are the slopes hard rock and/or impermeable, or relatively permeable, or; do the slopes already have or are they proposed to have subdrains (i.e., stabilization fills, etc.)? • Was the lot at the base of the slope overexcavated or is it proposed to be overexcavated? Overexcavated lots located at the base of a slope could accumulate subsurface water along the base of the fill cap. • Are the slopes north facing? North facing slopes tend to receive less sunlight (less evaporation) relative to south facing slopes and are more exposed to the currently prevailing seasonal storm tracks. • What is the slope height? It has been our experience that slopes with heights in excess of approximately 10 feet tend to have more problems due to storm runoff and irrigation than slopes of a lesser height. • Do the slopes "toe out" into a residential lot or a lot where perched or ponded water may adversely impact its proposed use? Based on these general criteria, the construction of toe drains may be considered by the design engineer along the toe of slopes, or at retaining walls in slopes, descending to the rear of such lots. Following are Detail 4 (Schematic Toe Drain Detail) and Detail 5 (Subdrain Along Retaining Wall Detail). Other drains may be warranted due to unforeseen conditions, homeowner irrigation, or other circumstances. Where drains are constructed during grading, including subdrains. the locations/elevations of such drains should be sun/eyed, and recorded on the final as-built grading plans by the design engineer. It is recommended thatthe above be disclosed to all interested parties, including homeowners and any homeowners association. Erosion Control Cut and fill slopes will be subject to surficial erosion during and after grading. Onsite earth materials have a moderate to high erosion potential. Consideration should be given to providing hay bales and silt fences for the temporary control of surface water, from a geotechnical viewpoint. Landscape Maintenance Only the amount of irrigation necessary to sustain plant life should be provided. Over-watering the landscape areas will adversely affect proposed site improvements. We would recommend that any proposed open-bottom planters adjacent to proposed structures be eliminated for a minimum distance of 10 feet. As an alternative, closed- bottom type planters could be utilized. An outlet placed in the bottom ofthe planter, could be installed to direct drainage away from structures or any exterior concrete flatwork. If Salmon Insuranco W.O. 4397-A-SC 955 Grand Avenue June 21, 2004 File:e:\wp9\4300\4397a.pge Page 28 GeoSoils, Inc. DETAILS N.T.S. SCHEMATIC TOE DRAIN DETAIL Pad grade Drain Pipe Drain May Be Constructed into, or at, the Toe of Slope 12" 12" Minimum 24" Minimum NOTES: 1. ) Soil Cap Compacted to 90 Percent Relative Compaction. 2. ) Permeable Material May Be Gravel Wrapped in Filter Fabric (Mirafi 140N or Equivalent). 3. ) 4-Inch Diameter Perforated Pipe (SDR 35 or Equivalent) with Perforations Down. 4. ) Pipe to Maintain a Minimum 1 Percent Fail. 5. ) Concrete Cutoff Wall to be Provided at Transition to Solid Outlet Pipe. 6. ) Solid Outlet Pipe to Drain to Approved Area. 7. ) Cleanouts are Recomended at Each Property Line. SCHEMATIC TOE DRAIN DETAIL DETAIL 4 Geotechnical • Coastal • Geologic • Environmental TOP OF WALL RETAINING WALL FINISHED GRADE JJ^III^ WALL FOOTING DETAILS N.T.S. 2:1 SLOPE (TYPICAL) BACKFILL WITH COMPATED NATIVE SOILS MIRAFI 140 FILTER FABRIC OR EQUAL 3/4" CRUSHED GRAVEL 4" DRAIN NOTES: 1. ) Soil Cap Compacted to 90 Percent Relative Compaction. 2. ) Permeable Material May Be Gravel Wrapped in Filter Fabric (Mirafi 140N or Equivalent). 3. ) 4-inch Diameter Perforated Pipe (SDR-35 of Equivalent) with Perforations Down. 4. ) Pipe to Maintain a Minimum 1 Percent Fall. 5. ) Concrete Cutoff Wall to be Provided at Transition to Solid Outlet Pipe. 6. ) Solid Outiet Pipe to Drain to Approved Area. 7. ) Cleanouts are Recommended at Each Property Line. 8. ) Compacted Effort Should Be Applied to Drain Rock. 1-T0 2' SUBDRAIN ALONG RETAINING WALL DETAIL NOT TO SCALE SUBDRAIN ALONG RETAINING WALL DETAIL DETAIL 5 Geotechnical • Coastal • Geologic • Environmental planters are constructed adjacent to structures, the sides and bottom ofthe planter should be provided with a moisture barrier to prevent penetration of irrigation water into the subgrade. Provisions should be made to drain the excess irrigation water from the planters without saturating the subgrade below or adjacent to the planters. Graded slope areas should be planted with drought resistant vegetation. Consideration should be given tothe type of vegetation chosen and their potential effect upon surface improvements (i.e., some trees will have an effect on concrete flatwork with their extensive root systems). From a geotechnical standpoint leaching is not recommended for establishing landscaping. Ifthe surface soils are processed for the purpose of adding amendments, they should be recompacted to 90 percent minimum relative compaction. Gutters and Downspouts As previously discussed in the drainage section, the installation of gutters and downspouts should be considered to collect roof water that may othen/vise infiltrate the soils adjacent to the structures. If utilized, the downspouts should be drained into PVC collector pipes or non-erosive devices that will carry the water away from the house. Downspouts and gutters are not a requirement; however, from a geotechnical viewpoint, provided that positive drainage is incorporated into project design (as discussed previously). Subsurface and Surface Water Subsurface and surface water are not anticipated to affect site development, provided that the recommendations contained in this report are incorporated into final design and construction and that prudent surface and subsurface drainage practices are incorporated into the construction plans. Perched groundwater conditions along zones of contrasting permeabilities may not be precluded from occurring in the future due to site irrigation, poor drainage conditions, or damaged utilities, and should be anticipated. Should perched groundwater conditions develop, this office could assess the affected area(s) and provide the appropriate recommendations to mitigate the observed groundwater conditions. Groundwater conditions may change with the introduction of irrigation, rainfall, or other factors. Site Improvements Recommendations for exterior concrete flatwork design and construction can be provided upon request. If in the future, any additional Improvements (e.g., pools, spas, etc.) are planned forthe site, recommendations concerning the geological or geotechnical aspects of design and construction of said improvements could be provided upon request. This office should be notified in advance of any fill placement, grading of the site, or trench backfilling after rough grading has been completed. This includes any grading, utility trench, and retaining wall backfills. Salmon Insuranco W.O. 4397-A-SC 955 Grand Avenue June 21, 2004 File:e:\wp9\4300\4397a.pge Page 31 GeoSoils, Inc. Tile Flooring Tilefiooring can crack, reflecting cracks in the concrete slab below the tile, although small cracks in a conventional slab may not be significant. Therefore, the designer should consider additional steel reinforcement for concrete slabs-on-grade where tile will be placed. The tile installer should consider installation methods that reduce possible cracking of the tile such as slipsheets. Slipsheets or a vinyl crack isolation membrane (approved by the Tile Council of America/Ceramic Tile Institute) are recommended between tile and concrete slabs on grade. Additional Grading This office should be notified in advance of any fill placement, supplemental regrading of the site, or trench backfilling after rough grading has been completed. This includes completion of grading in the street and parking areas and utility trench and retaining wall backfills. Footing Trench Excavation All footing excavations should be observed by a representative ofthis firm subsequent to trenching and prior to concrete form and reinforcement placement. The purpose of the observations is to verify that the excavations are made into the recommended bearing material and to the minimum widths and depths recommended for construction. If loose or compressible materials are exposed within the footing excavation, a deeper footing or removal and recompaction of the subgrade materials would be recommended atthattime. Footing trench spoil and any excess soils generated from utility trench excavations should be compacted to a minimum relative compaction of 90 percent, if not removed from the site. Trenching Considering the nature ofthe onsite soils, it should be anticipated that caving or sloughing could be a factor in subsurface excavations and trenching. Shoring or excavating the trench walls at the angle of repose (typically 25 to 45 degrees) may be necessary and should be anticipated. All excavations should be observed by one of our representatives and minimally conform to CAL-OSHA and local safety codes. Utilitv Trench Backfill 1. All interior utility trench backfill should be brought to at least 2 percent above optimum moisture content and then compacted to obtain a minimum relative compaction of 90 percent ofthe laboratory standard. As an alternative for shallow (12-inch to 18-inch) under-slab trenches, sand having a sand equivalent value of Salmon Insuranco W.O. 4397-A-SC 955 Grand Avenue June 21, 2004 File:e:\wp9\4300\4397a.pge Page 32 GeoSoils, Inc. 30 or greater may be utilized and jetted or flooded into place. Observation, probing and testing should be provided to verify the desired results. 2. Exterior trenches adjacent to, and within areas extending below a 1:1 plane projected from the outside bottom edge of the footing, and all trenches beneath hardscape features and in slopes, should be compacted to at least 90 percent of the laboratory standard. Sand backfill, unless excavated from the trench, should not be used in these backfill areas. Compaction testing and observations, along with probing, should be accomplished to verify the desired results. 3. All trench excavations should conform to CAL-OSHA and local safety codes. 4. Utilities crossing grade beams, perimeter beams, or footings should either pass below the footing or grade beam utilizing a hardened collar or foam spacer, or pass through the footing or grade beam in accordance with the recommendations ofthe structural engineer. SUMMARY OF RECOMMENDATIONS REGARDING GEOTECHNiCAL OBSERVATION AND TESTING We recommend that obsen/ation and/or testing be performed by GSI at each of the following construction stages: • During grading/recertiflcation. • During significant excavation (i.e., higher than 4 feet). • During placement of subdrains, toe drains, or other subdrainage devices, prior to placing fill and/or backfill. • After excavation of building footings, retaining wall footings, and free standing walls footings, prior to the placement of reinforcing steel or concrete. • Prior to pouring any slabs or flatwork, after presoaking/presaturation of building pads and other flatwork subgrade, before the placement of concrete, reinforcing steel, capillary break (i.e.. sand, pea-gravel, etc.), or vapor barriers (i.e., visqueen, etc.). • During retaining wall subdrain installation, prior to backfill placement. • During placement of backfill for area drain, interior plumbing, utility line trenches, and retaining wall backfill. Salmon Insuranco W.O. 4397-A-SC 955 Grand Avenue June 21, 2004 File:e:\wp9\4300\4397a.pge Page 33 GeoSoils, Inc. During slope construction/repair. When any unusual soil conditions are encountered during any construction operations, subsequent to the issuance of this report. When any developer or homeowner improvements, such as flatwork, spas, pools, walls, etc., are constructed. A report of geotechnical observation and testing should be provided at the conclusion of each of the above stages, in order to provide concise and clear documentation of site work, and/or to comply with code requirements. OTHER DESIGN PROFESSIONALS/CONSULTANTS The design civil engineer, structural engineer, post-tension designer, architect, landscape architect, wall designer, etc., should review the recommendations provided herein. Incorporate those recommendations into all their respective plans, and by explicit reference, make this report part of their project plans. In order to mitigate potential distress, the foundation and/or improvement's designer should confirm to GSI and the governing agency, in writing, that the proposed foundations and/or improvements can tolerate the amount of differential settlement and/or expansion characteristics and design criteria specified herein. PLAN REVIEW Final project plans should be reviewed by this office prior to construction, so that construction is in accordance with the conclusions and recommendations of this report. Based on our review, supplemental recommendations and/or further geotechnical studies may be warranted. Salmon Insuranco W.O. 4397-A-SC 955 Grand Avenue June 21, 2004 File:e:\wp9\4300\4397a.pge Page 34 GeoSoils, Inc. LIMITATIONS The materials encountered on the project site and utilized for our analysis are believed representative ofthe area; however, soil and bedrock materials vary in character between excavations and natural outcrops or conditions exposed during mass grading. Site conditions may vary due to seasonal changes or other factors. Inasmuch as our study is based upon our review and engineering analyses and laboratory data, the conclusions and recommendations are professional opinions. These opinions have been derived in accordance with current standards of practice, and no warranty is expressed or implied. Standards of practice are subject to change with time. GSI assumes no responsibility or liability for work or testing performed by others, or their inaction; or work performed when GSI is not requested to be onsite, to evaluate if our recommendations have been properiy implemented. Use of this report constitutes an agreement and consent by the user to all the limitations outlined above, notwithstanding any other agreements that may be in place. In addition, this report may be subject to review by the controlling authorities. Thus, this report brings to completion our scope of services for this project. Salmon insuranco 955 Grand Avenue File:e:\wp9\4300\4397a.pge W.O. 4397-A-SC June 21.2004 Page 35 GeoSoils, Inc. APPENDIX A REFERENCES APPENDIX A REFERENCES Blake, T.F., 2000a, EQFAULT, A computer program forthe estimation of peak horizontal acceleration from 3-D fault sources; Windows 95/98 version. , 2000b, EQSEARCH, A computer program for the estimation of peak horizontal acceleration from California historical earthquake catalogs; Windows 95/98 version. , 2000c, FRISKSP, A computer program for the probabilistic estimation of peak acceleration and uniform hazard spectra using 3-D faults as earthquake sources; Windows 95/98 version. Bozorgnia. Y., Campbell, K.W.. and Niazi, M., 1999, Vertical ground motion: Characteristics, relationship with horizontal component, and building-code implications; Proceedings of the SMIP99 seminar on utilization of strong-motion data, September, 15, Oakland, pp. 23-49. Campbell, K.W. and Bozorgnia, Y. 1997, Attenuation relations for soft rock conditions; jn EQFAULT, A computer program for the estimation of peak horizontal acceleration from 3-D fault sources; Windows 95/98 version, Blake, 2000a. , Y., 1994, Near-source attenuation of peak horizontal acceleration from worldwide accelrograms recorded from 1957 to 1993; Proceedings, Fifth U.S. National Conference on Earthquake Engineering, Volume III, Earthquake Engineering Research Institute, pp 292-293. Hart, E.W. and Bryant, W.A. 1997, Fault-rupture hazard zones in California, Alquist-Priolo earthquake fault zoning act with Indexto Earthquake Fault Maps; California Division of Mines and Geology Special Publication 42. International Conference of Building Officials, 1997. Uniform building code: Whittier, California, vol. 1, 2, and 3. Jennings, C.W., 1994, Fault activity map of California and adjacent areas: California Division of Mines and Geology, Map Sheet No. 6, scale 1:750.000. Joyner, W.B, and Boore, D.M., 1982a. Estimation of response-spectral values as functions of magnitude, distance and site conditions, io eds., Johnson, J.A., Campbell, K.W., and Blake, T.F.: AEG Short Course, Seismic Hazard Analysis, June 18,1994. , 1982b, Prediction of earthquake response spectra, U.S. Geological Survey Open- File Report 82-977, 16p. GeoSoils, Inc. Parker, Claude B., Geotechnical Consultant, Preliminary geotechnical report for proposed residential structure, 5480 Carlsbad Boulevard, Carlsbad, County of San Diego, California, Job no. 82-471P, dated August 22,1982. Sadigh, K., Chang, C.-Y., Egan, J.A., Makdisi, F., and Youngs, R.R., 1997, Attenuation relations for shallow crustal earthquakes based on California strong motion data, Seismological Research Letters, Vol. 68. No. 1. pp. 180-189. Treiman. J.A., 1993, The Rose Canyon fault zone, southern California: California Division of Mines and Geology, Open File report OFR 93-02. , 1991, Rose Canyon fault zone, San Diego county, California: California division of Mines and Geology, fault Evaluation Report FER-216, July 10, revised January 25,1991,14p. Weber. F.H., 1982, Geologic map of north-central coastal area of San Diego County, California showing recent slope failures and pre-development landslides: California Department of Conservation, Division of Mines and Geology, OFR 82-12 LA. Wilson, K.L., 1972, Eocene and related geology of a portion of the San Luis Rey and Encinitas quadrangles, San Diego County, California: unpublished masters thesis. University of California, Riverside. Salmon Insurance Appendix A File:e:\wp9\4300\4397a.pge Page 2 GeoSoils, Inc. APPENDIX B HAND AUGER BORING LOGS BORING LOG GeoSoils, Inc. PROJECT: SALMEN 955 Garnet Avenue W.O. 4397-A-SC BORING B-1 Sample 11 m Z33 OT5 " E 3 w .t: a. c ^ D O D>i»T££X'CAW\rED S/IMPLE METHOD: HAND AUGER SHEET 1 OF 1 6-11-04 Standard Penetration Test Undisturbed, Ring Sample 2 Groundwater Description of Material SM TOPSOIL: (g 0' SILTY SAND, brown, damp, loose. SM TERRACE DEPOSITS: @ V SILTY SAND, red brown, damp, medium dense. 104.4 5.4 24.4 5- Total Depth = 4' No Groundwater Encountered Backfilled 6-11-2004 955 Garnet Avenue GeoSoils, Inc. PLATE B-1 BORING LOG GeoSoils, Inc. PROJECT: SALMEN 955 Garnet Avenue W.O. 4397-A-SC BORING B-2 Sample IS m O E OT ^ D OT a OT DATEEXCAVATED SAMPLE METHOD: HAND AUGER SHEET 1 OF 1 6-11-04 Standard Penetration Test Undisturbed, Ring Sample 2 ^ Groundwater Description of Material SM TOPSOIL: (g 0' SILTY SAND, brown, damp, loose. SM TERRACE DEPOSITS: @ 1' SILTY SAND, red brown, damp, medium dense. 5- Total Depth = 3' No Groundwater Encountered Backfilled 6-11-2004 955 Garnet Avenue GeoSoils, Inc. PLATE B-2 APPENDIX C EQFAULT, EQSEARCH, AND FRISKSP MAXIMUM EARTHQUAKES Salmen c o CO 0) CD O O < .1 01 -= 001 .1 1 10 Distance (mi) 100 W.O. 4397-A-SC Plate C-1 EARTHQUAKE RECURRENCE CURVE (0 0) tn •*-> c > LU 0 E z 0) .> E E o Salmen 100 10 .01 .001 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 Magnitude (IVI) W.O. 4397-A-SC Plate C-2 p (O I > I o RETURN PERIOD vs. ACCELERATION CAMP. & BOZ. (1997 Rev.) SR 1 1000000 (0 TD O 0) Q. c 01 2 0) O 100000 10000 1000 100 0.00 0.25 0.50 0.75 1.00 Acceleration (g) 1.25 1.50 PROBABILITY OF EXCEEDANCE CAMP. & BOZ. (1997 Rev.) SR 1 100 25 yrs 75 yrs 50 yrs 100 yrs 0.00 0.25 0.50 0.75 1.00 1.25 1.50 Acceleration (g) W.O. 4397-A-SC Plate C-4 APPENDIX D GENERAL EARTHWORK AND GRADING GUIDELINES GENERAL EARTHWORK AND GRADING GUIDELINES General These guidelines present general procedures and requirements for earthwork and grading as shown on the approved grading plans, including preparation of areas to filled, placement of fill, installation of subdrains and excavations. The recommendations contained in the geotechnical report are part ofthe earthwork and grading guidelines and would supercede the provisions contained hereafter in the case of conflict. Evaluations performed by the consultant during the course of grading may result in new recommendations which could supersede these guidelines or the recommendations contained in the geotechnical report. The contractorls responsible forthe satisfactory completion of all earthwork in accordance with provisions of the project plans and specifications. The project soil engineer and engineering geologist (geotechnical consultant) or their representatives should provide observation and testing services, and geotechnical consultation during the duration ofthe project. EARTHWORK OBSERVATIONS AND TESTING Geotechnical Consultant Priorto the commencement of grading, a qualified geotechnical consultant (soil engineer and engineering geologist) should be employed for the purpose of observing earthwork procedures and testing the fills for conformance with the recommendations of the geotechnical report, the approved grading plans, and applicable grading codes and ordinances. The geotechnical consultant should provide testing and observation so that determination may be made that the work is being accomplished as specified. It is the responsibility of the contractor to assist the consultants and keep them apprised of anticipated work schedules and changes, so that they may schedule their personnel accordingly. All clean-outs, prepared ground to receive fill, key excavations, and subdrains should be observed and documented bythe project engineering geologist and/or soil engineer prior to placing and fill. It is the contractors's responsibility to notify the engineering geologist and soil engineer when such areas are ready for observation. Laboratorv and Fieid Tests Maximum dry density tests to determine the degree of compaction should be performed in accordance with American Standard Testing Materials test method ASTM designation D-1557-78. Random field compaction tests should be performed in accordance with test method ASTM designation D-1556-82, D-2937 or D-2922 and D-3017. at inten/als of approximately 2 feet of fill height or every 100 cubic yards of fill placed. These criteria GeoSoils, Inc. would vary depending on the soil conditions and the size ofthe project. The location and frequency of testing would be at the discretion ofthe geotechnical consultant. Contractor's Responsibility All clearing, site preparation, and earthwork performed on the project should be conducted by the contractor, with observation by geotechnical consultants and staged approval by the governing agencies, as applicable. It is the contractor's responsibility to prepare the ground surface to receive the fill, to the satisfaction of the soil engineer, and to place, spread, moisture condition, mix and compact the fill In accordance with the recommendations ofthe soil engineer. The contractor should also remove all major non- earth material considered unsafisfactory by the soil engineer. It is the sole responsibility ofthe contractor to provide adequate equipment and methods to accomplish the earthwork In accordance with applicable grading guidelines, codes or agency ordinances, and approved grading plans. Sufficient watering apparatus and compacfion equipment should be provided by the contractor with due considerafion for the fill material, rate of placement, and climafic condifions. If, in the opinion of the geotechnical consultant, unsafisfactory conditions such as quesfionable weather, excessive oversized rock, or deleterious material, insufficient support equipment, etc., are resulfing in a quality of work that is not acceptable, the consultant will Inform the contractor, and the contractor is expected to rectify the conditions, and if necessary, stop work until condifions are satisfactory. During construcfion, the contractor shall properly grade all surfaces to maintain good drainage and prevent ponding of water. The contractor shall take remedial measures to control surface water and to prevent erosion of graded areas unfil such fime as permanent drainage and erosion control measures have been installed. SITE PREPARATION All major vegetafion, including brush, trees, thick grasses, organic debris, and other deleterious material should be removed and disposed of off-site. These removals must be concluded prior to placing fill. Exisfing fill, soil, alluvium, colluvium, or rock materials determined by the soil engineer or engineering geologist as being unsuitable in-place should be removed prior to fill placement. Depending upon the soil condifions, these materials may be reused as compacted fills. Any materials Incorporated as part of the compacted fills should be approved by the soil engineer. Any underground structures such as cesspools, cisterns, mining shafts, tunnels, sepfic tanks, wells, pipelines, or other structures not located prior to grading are to be removed or treated in a manner recommended by the soil engineer. Soft, dry, spongy, highly fractured, or otherwise unsuitable ground extending to such a depth that surface processing cannot adequately improve the condifion should be overexcavated down to Salmon Insurance Appendix D File:e:\wp9\4300\4397a.pge Page 2 GeoSoils, Inc. firm ground and approved by the soil engineer before compacfion and filling operafions confinue. Overexcavated and processed soils which have been properly mixed and moisture condifioned should be re-compacted to the minimum relative compacfion as specified in these guidelines. Exisfing ground which is determined to be satisfactory for support of the fills should be scarified to a minimum depth of 6 inches or as directed by the soil engineer. After the scarified ground is brought to opfimum moisture content or greater and mixed, the materials should be compacted as specified herein. If the scarified zone is grater that 6 inches in depth, it may be necessary to remove the excess and place the material in lifts restricted to about 6 inches in compacted thickness. Existing ground which is not satisfactory to support compacted fill should be overexcavated as required in the geotechnical report or by the on-site soils engineer and/or engineering geologist. Scarificafion, disc harrowing, or other acceptable form of mixing should confinue unfil the soils are broken down and free of large lumps or clods, until the working surface is reasonably uniform and free from ruts, hollow, hummocks, or other uneven features which would inhibit compaction as described previously. Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical), the ground should be stepped or benched. The lowest bench, which will act as a key, should be a minimum of 15 feet wide and should be at least 2 feet deep into firm material, and approved by the soli engineer and/or engineering geologist. In fill over cut slope conditions, the recommended minimum width of the lowest bench or key is also 15 feet with the key founded on firm material, as designated bythe Geotechnical Consultant. As a general rule, unless specifically recommended otherwise by the Soil Engineer, the minimum width of fill keys should be approximately equal to VT. the height of the slope. Standard benching is generally 4 feet (minimum) vertically, exposing firm, acceptable material. Benching may be used to remove unsuitable materials, although it is understood that the vertical height ofthe bench may exceed 4 feet. Pre-stripping may be considered for unsuitable materials in excess of 4 feet in thickness. All areas to receive fill, including processed areas, removal areas, and the toe of fill benches should be observed and approved by the soil engineer and/or engineering geologist prior to placement of fill. Fills may then be properiy placed and compacted unfil design grades (elevafions) are attained. COMPACTED FILLS Any earth materials imported or excavated on the property may be ufilized in the fill provided that each material has been determined to be suitable by the soil engineer. These materials should be free of roots, tree branches, other organic matter or other Salmon insuranco Appendix D File:e:\wp9\4300\4397a.pge Page 3 GeoSoils, Inc. deleterious materials. All unsuitable materials should be removed from the fill as directed by the soil engineer. Soils of poor gradafion, undesirable expansion potenfial, or substandard strength characterisfics may be designated by the consultant as unsuitable and may require blending with other soils to serve as a satisfactory fill material. Fill materials derived from benching operafions should be dispersed throughout the fill area and blended with other bedrock derived material. Benching operafions should not result in the benched material being placed only within a single equipment width away from the fill/bedrock contact. Oversized materials defined as rock or other irreducible materials with a maximum dimension greater than 12 inches should not be buried or placed in fills unless the locafion of materials and disposal methods are specifically approved by the soil engineer. Oversized material should betaken off-site or placed in accordance with recommendafions ofthe soil engineer in areas designated as suitable for rock disposal. Oversized material should not be placed within 10 feet vertically of finish grade (elevafion) or within 20 feet horizontally of slope faces. To facilitate future trenching, rock should not be placed within the range of foundafion excavafions, future ufilities, or underground construction unless specifically approved by the soil engineer and/or the developers representafive. If import material is required for grading, representative samples of the materials to be ufilized as compacted fill should be analyzed in the laboratory by the soil engineer to determine its physical properties. If any material other than that previously tested is encountered during grading, an appropriate analysis ofthis material should be conducted by the soil engineer as soon as possible. Approved fill material should be placed in areas prepared to receive fill in near horizontal layers that when compacted should not exceed 6 inches in thickness. The soil engineer may approve thick lifts if testing Indicates the grading procedures are such that adequate compaction Is being achieved with lifts of greater thickness. Each layer should be spread evenly and blended to attain uniformity of material and moisture suitable for compaction. Fill layers at a moisture content lessthan opfimum should be watered and mixed, and wet fill layers should be aerated by scarification or should be blended with drier material. Moisture condifion, blending, and mixing of the fill layer should confinue unfil the fill materials have a uniform moisture content at or above optimum moisture. After each layer has been evenly spread, moisture conditioned and mixed, it should be uniformly compacted to a minimum of 90 percent of maximum density as determined by ASTM test designafion, D-1557-78. or as otherwise recommended by the soil engineer. Compacfion equipment should be adequately sized and should be specifically designed for soil compaction or of proven reliability to efficienfiy achieve the specified degree of compacfion. Salmon Insuranco Appendix D File:e:\wp9\4300\4397a.pge Page 4 GeoSoils, Inc. Where tests indicate that the density of any layer of fill, or portion thereof, is below the required relative compacfion, or improper moisture is in evidence, the particular layer or portion shall be re-worked unfil the required density and/or moisture content has been attained. No addifional fill shall be placed in an area unfil the last placed lift of fill has been tested and found to meet the density and moisture requirements, and is approved by the soil engineer. Compacfion of slopes should be accomplished by over-building a minimum of 3 feet horizontally, and subsequently trimming back to the design slope configuration. Tesfing shall be performed as the fill is elevated to evaluate compacfion as the fill core is being developed. Special efforts may be necessary to attain the specified compaction in the fill slope zone. Final slope shaping should be performed by trimming and removing loose materials with appropriate equipment. Afinal determinafion of fill slope compacfion should be based on observafion and/or tesfing of the finished slope face. Where compacted fill slopes are designed steeper than 2:1 (horizontal to vertical), specific material types, a higher minimum relafive compacfion, and special grading procedures, may be recommended. If an alternative to over-building and cutting back the compacted fill slopes is selected, then special effort should be made to achieve the required compacfion in the outer 10 feet of each lift of fill by undertaking the following: 1. An extra piece of equipment consisfing of a heavy short shanked sheepsfoot should be used to roll (horizontal) parallel to the slopes confinuously as fill Is placed. The sheepsfoot roller should also be used to roll perpendicular to the slopes, and extend out over the slope to provide adequate compaction to the face of the slope. 2. Loose fill should not be spilled out over the face of the slope as each lift is compacted. Any loose fill spilled over a previously completed slope face should be trimmed off or be subject to re-rojiing. 3. Field compacfion tests will be made in the outer (horizontal) 2 to 8 feet of the slope at appropriate vertical intervals, subsequent to compacfion operafions. 4. After complefion of the slope, the slope face should be shaped with a small tractor and then re-rolled with a sheepsfoot to achieve compacfion to near the slope face. Subsequent to tesfing to verify compaction, the slopes should be grid-rolled to achieve compaction to the slope face. Final tesfing should be used to confirm compacfion after grid rolling. 5. Where tesfing indicates less than adequate compacfion, the contractor will be responsible to rip, water, mix and re-compact the slope material as necessary to achieve compaction. Additional tesfing should be performed to verify compacfion. Salmon Insuranco Appendix D File:e:\wp9\4300\4397a.pge Page 5 GeoSoils, Inc. Erosion control and drainage devices should be designed by the project civil engineer in compliance with ordinances ofthe controlling governmental agencies, and/or in accordance with the recommendafion ofthe soil engineer or engineering geologist. SUBDRAIN INSTALLATION Subdrains should be installed in approved ground in accordance with the approximate alignment and details indicated by the geotechnical consultant. Subdrain locafions or materials should not be changed or modified without approval of the geotechnical consultant. The soil engineer and/or engineering geologist may recommend and direct changes in subdrain line, grade and drain material In the field, pending exposed condifions. The locafion of constructed subdrains should be recorded by the project civil engineer. EXCAVATIONS Excavafions and cut slopes should be examined during grading by the engineering geologist. If directed by the engineering geologist, further excavafions or overexcavafion and re-filling of cut areas should be performed and/or remedial grading of cut slopes should be performed. When fill over cut slopes are to be graded, unless otherwise approved, the cut portion ofthe slope should be observed by the engineering geologist prior to placement of materials for construction ofthe fill portion of the slope. The engineering geologist should observe all cut slopes and should be notified by the contractor when cut slopes are started. If, during the course of grading, unforeseen adverse or potential adverse geologic conditions are encountered, the engineering geologist and soil engineer should investigate, evaluate and make recommendations to treat these problems. The need for cut slope buttressing or stabilizing should be based on in-grading evaluation by the engineering geologist, whether anficipated or not. Unless OthenA/ise specified in soil and geological reports, no cut slopes should be excavated higher or steeper than that allowed by the ordinances of controlling governmental agencies. Addifionally, short-term stability of temporary cut slopes is the contractors responsibility. Erosion control and drainage devices should be designed bythe project civil engineer and should be constructed in compliance with the ordinances ofthe controlling governmental agencies, and/or In accordance with the recommendafions of the soil engineer or engineering geologist. Salmon insuranco Appendix D Flle:e:\wp9\4300\4397a.pge Page 6 GeoSoils, Inc. COMPLETION Observafion, tesfing and consultafion bythe geotechnical consultant should be conducted during the grading operafions in order to state an opinion that all cut and filled areas are graded in accordance with the approved project specificafions. After complefion of grading and after the soil engineer and engineering geologist have finished their observafions ofthe work, final reports should be submitted subject to review by the controlling governmental agencies. No further excavafion or filling should be undertaken without prior notificafion of the soil engineer and/or engineering geologist. All finished cut and fill slopes should be protected from erosion and/or be planted In accordance with the project specifications and/or as recommended by a landscape architect. Such protection and/or planning should be undertaken as soon as pracfical after complefion of grading. JOB SAFETY General At GeoSoils, Inc. (GSI) getting the job done safely Is of primary concern. The following is the company's safety considerafions for use by all employees on mulfi-employer construcfion sites. On ground personnel are at highest risk of injury and possible fatality on grading and construcfion projects. GSI recognizes that construcfion activifies will vary on each site and that site safety is the prime responsibility of the contractor; however, everyone must be safety conscious and responsible at all fimes. To achieve our goal of avoiding accidents, cooperation between the client, the contractor and GSI personnel must be maintained. In an effort to minimize risks associated with geotechnical tesfing and observafion, the following precaufions are to be Implemented for the safety of field personnel on grading and construction projects: Safety Meetings: GSI field personnel are directed to attend contractors regularly scheduled and documented safety meefings. Safety Vests: Safety vests are provided for and are to be worn by GSI personnel at all fimes when they are working in the field. Safety Flags: Two safety flags are provided to GSI 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. Salmon Insuranco Appendix D File:e:\wp9\4300\4397a.pge Page 7 GeoSoils, Inc. Flashing Lights: All vehicles stafionary in the grading area shall use rotafing or fiashing amber beacon, or strobe lights, on the vehicle during all field tesfing. While operafing a vehicle in the grading area, the emergency flasher on the vehicle shall be acfivated. 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 attenfion of our office. Test Pits Location. Orientation and Clearance The technician is responsible for selecfing test pit locations. A primary concern should be the technicians's safety. Efforts will be made to coordinate locafions with the grading contractors authorized representafive, and to select locafions following or behind the established traffic pattern, preferably outside of current traffic. The contractors authorized representafive (dump man. operator, supervisor, grade checker, etc.) should direct excavafion of the pit and safety during the test period. Of paramount concern should be the soil technicians safety and obtaining enough tests to represent the fill. Test pits should be excavated so that the spoil pile is placed away form oncoming traffic, whenever possible. The technician's vehicle is to be placed next to the test pit, opposite the spoil pile. This necessitates the fill be maintained In a driveable condifion. Alternatively, the contractor may wish to park a piece of equipment in front of the test holes, particulariy in small fill areas or those with limited access. A zone of non-encroachment should be established for all test pits. No grading equipment should enter this zone during the tesfing procedure. The zone should extend approximately 50 feet outward from the center ofthe test pit. This zone is established for safety and to avoid excessive ground vibrafion which typically decreased test results. When taking slope tests the technician should park the vehicle directly above or below the test locafion. If this is not possible, a prominent fiag should be placed at the top of the slope. The contractor's representative should effecfively keep all equipment at a safe operafion distance (e.g., 50 feet) away from the slope during this tesfing. The technician Is directed to withdraw from the active portion ofthe fill as soon as possible following tesfing. The technician's vehicle should be parked at the perimeter of the fill in a highly visible locafion, well away from the equipment traffic pattern. The contractor should inform our personnel of all changes to haul roads, cut and fill areas or other factors that may affect site access and site safety. In the event that the technicians safety is jeopardized or compromised as a result of the contractors failure to comply with any ofthe above, the technician is required, by company policy, to immediately withdraw and notify his/her supervisor. The grading contractors representative will eventually be contacted in an effort to effect a solufion. However, in the Salmon Insuranco Appendix D File:e:\wp9\4300\4397a.pge Page 8 GeoSoils, Inc. interim, no further tesfing will be performed unfil the situafion is rectified. Any fill place can be considered unacceptable and subject to reprocessing, recompacfion or removal. In the event that the soil technician does not comply with the above or other established safety guidelines, we request that the contractor brings this to his/her attenfion and notify this office. Effective communication and coordination between the contractors representafive and the soils technician is strongly encouraged in order to implement the above safety plan. Trench and Vertical Excavation It is the contractor's responsibility to provide safe access into trenches where compacfion tesfing is needed. Our personnel are directed not to enter any excavafion or vertical cut which: 1) is 5 feet or deeper unless shored or laid back; 2) displays any evidence of instability, has any loose rock or other debris which could fall into the trench; or 3) displays any other evidence of any unsafe condifions regardless of depth. All trench excavations or vertical cuts in excess of 5 feet deep, which any person enters, should be shored or laid back. Trench access should be provided in accordance with CAL-OSHA and/or state and local standards. Our personnel are directed not to enter any trench by being lowered or "riding down" on the equipment. If the contractor fails to provide safe access to trenches for compacfion tesfing, our company policy requires that the soil technician withdraw and notify his/her supervisor. The contractors representafive will eventually be contacted in an effort to effect a solufion. All backfill not tested due to safety concerns or other reasons could be subject to reprocessing and/or removal. If GSI personnel become aware of anyone working beneath an unsafe trench wall or vertical excavafion, we have a legal obligafion to put the contractor and owner/developer on nofice to immediately correct the situafion. If corrective steps are not taken, GSI then has an obligafion to notify CAL-OSHA and/or the proper authorities. Salmon Insuranco Appendix D File:e:\wp9\4300\4397a.pge Page 9 GeoSoils, Inc. CANYON SUBDRAIN DETAIL TYPE A PROPOSED COMPACTED FILL NATURAL GROUND COLLUVIUM AND ALLUVIUM (REMOVE) TYPICAL BENCHING '/^^. \^ BEDROCK SEE ALTERNATIVES TYPE B PROPOSED COMPACTED RLL NATURAL GROUND COLLUVIUM AND ALLUVIUM iREMOVEl l/Z/ggi^W' BEDROCK TYPICAL BENCHING SEE ALTERNATIVES NOTE: ALTERNATIVES. LOCATION AND EXTENT OF SUBDRAINS SHOULD BE DETERMINED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST DURING GRADING. PLATE EG-1 CANYON SUBDRAIN ALTERNATE DETAILS ALTERNATE 1: PERFORATED PIPE AND FILTER MATERIAL A~1 • MINIMUM 12" MINIMUM FILTER MATERIAL: MINIMUM VOLUME /LINEAR FT. ^ ABS OR PYC PIPE SUBSTITUTE WITH MINIMUM 8 Il/A"^PERFS. LINEAR FT. IN BOTTOM HALF OF PIPE. ASTM D2751. SDR 35 OR ASTM D1527. SCHD, AO ASTM D303A, SDR 35 OR ASTM D17B5. SCHD, AO FOR CONTINUOUS RUN IN EXCESS OF 500 FT. USE B-JBT PIPE 6-MINIMUM B-1 FILTER MATERIAL. SIEVE SIZE PERCENT PASSING 1 INCH :100 3/A INCH .90-100 3/8 INCH AO-lOO NQ. A 25-AO. NO. 8 18-33 .NO. 30 -.5-15 NO. 50 .0-7 NO. 200 0-3 ALTERNATE 2: PERFORATED PIPE, GRAVEL AND.FILTER FABRIC 6 • MINIMUM OVERLAP 6" MINIMUM OVERLAP 6* MINIMUM COVER =A* MINIMUM BEDDING A-2 A" MINIMUM BEDDINGZir, — GRAVEL MATERIAL 9 FP/UNEAR FT. g_2 PERFORATED PIPE: SEE ALTERNATE 1 GRAVEL CLEAN 3/A INCH ROCK OR APPRC3VED SUBSTITUTE FILTER FABRIC: MIRAFI 1A0 OR APPROVED SUBSTITUTE I PLATE EG-2 DETAIL FOR FILL SLOPE TOEING OUT ON FLAT ALLUVIATED CANYON TOE OF SLOPE AS SHOWN ON GRADING PLAN ORIGINAL GROUND SURFACE TO BE RESTORED WITH COMPACTED FILL BACKCUT\.YARIES. FOR DEEP REMOVALS.^ BACKCUT ^VKSHOULD BE MADE NO ^ STEEPER THAlisi:! OR AS NECESSARY -<> FOR SAFETY i^/NMr-mcoATinMc / CONSIDERATIONS y ORIGINAL GROUND SURFACE COMPACTED RLL ANTICIPATED ALLUVIAL REMOVAL DEPTH PER SOIL ENGMEER. r PROVIDE A 1:1 MINIMUM PROJECTION FROM TOE OF SLOPE AS SHOWN ON GRADING PLAN TO THE RECOMMEMDED REMOVAL DEPTH. SLOPE HEIGHT. SITE CONDITIONS AMD/OR LOCAL CONDITIONS COULD DICTATE FLATTER PROJECTIONS. REMOVAL ADJACENT TO EXISTING FILL ADJOINING CANYON HLL COMPACTED RLL LIMITS LINE ^,,FOR DRAINAGE ONLY ^> Qaf /^Q\ (TO BE REMOVED), (EXISTING.COMPACTED FILL) ^\ / 7?7^^^jlf^l^ / Tn DP DCiuinvtrn otrcnDC TO BE REMOVED BEFORE PLACING ADDITIONAL COMPACTED RLL LEGEND Qaf ARTIFICIAL RLL Qal ALLUVIUM PLATE EG-3 TYPICAL STABILIZATION / BUTTRESS FILL DETAIL OUTLETS TO BE SPACED AT 100'MAXIMUM INTERVALS. AND SHALL EXTEND 12" BEYOND THE FACE OF SLOPE AT TIME OF.ROUGH GRADING COMPLETION. BLANKET FILL IF RECOMMENDED BY THE SOIL ENGINEER TYPICAL BENCHING A" DIAMETER NON-PERFORATED OUTLET PIPE AND BACKDRAIN (SEE ALTERNATIVES) > H m m o I ^ W=15*MINIMUM OR H/2 BEDROCK 3'MINIMUM KEY DEPTH TYPICAL STABILIZATION / BUTTRESS SUBDRAIN DETAIL A- MINIMUM 2" MINIMUM PIPE L' MINIMUM PIPE r" > m m o I 2- MINIMUM FILTER MATERIAL MINIMUM OF FIVE Fl'/LINEAR Ft OF PIPE OR FOUR FP/LINEAR F! OF PIPE WHEN PLACED IN SQUARE CUT TI^ENCH. ALTERNATIVE IN LIEU OF RLTER MATERIAL: GRAVEL MAY BE EMCASED IN APPROVED FILTER FABRIC. FILTER FABRIC SHALL BE MIRAFI IAO OR EQUIVALENT. FILTER FABRIC SHIALL BE LAPPED A MINIMUM OF 12' ON ALL JOINTS. MINIMUM A-DIAMETER PIPE: ABS-ASTM D-2751. SDR 35 OR ASTM D-1527 SCHEDULE AO PVC-ASTM D-303A. SpR 35 OR ASTM D-1785 SCHEDULE AO WITH A CRUSHING STRENGTH OF 1,000 POUNDS MINIMUM. AND A MINIMUM OF 8 UNIFORMLY SPACED PERFORATIONS PER FOOT OF PIPE INSTALLED WITH PERFORATIONS OF BOTTOM OF PIPE. PROVIDE CAP AT UPSTREAM END OF PIPE. SLOPE AT 2% TO OUTLET PIPE. OUTLET PIPE TO BE CONNECTED TO SUBDRAIN PIPE WITH TEE OR ELBOW. NOTE: 1. TRENCH FOR OUTLET PIPES TO BE BACKRLLED • WITH ON-SITE SOIL 2. BACKDRAINS AND LATERAL DRAINS SHALL BE LOCATED AT ELEVATION OF EVERY BENCH DRAIN. . RRST DRAIN LOCATED AT ELEVATION JUST ABOVE LOWER LOT GRADE. ADDITIONAL DRAINS MAY BE REQUIRED AT THE DISCRETION OF THE SOILS * ENGINEER AND/OR ENGINEERING GEOLOGIST. FILTER MATERIAL SHALL BE OF THE FOLLOWING SPECIFICATION OR AN APPROVED EQUIVALENT: 1 INCH 100 3/A INCH 90-100 3/8 INCH A0-100 NO. A 25-AO NO. 8 18-33 NO. 30 5-15 NO. 50 0-7 NO. 200 0-3 GRAVEL SHALL BE OF THE FOLLOWING SPECIFICATION OR AN APPROVED EQUIVALENT: SIEVE SIZE PERCENT PASSING 1 1/2 INCH 100 NO. A 50 NO. 200 8 SAND EQUIVALENT: MINIMUM OF 51 FILL OVER NATURAL DETAIL SIDEHILL FILL PROPOSED GRADE TOE OF SLOPE AS SHOWN ON GRADINO PLAN PROVIDE A 1:1 MINIMUM PROJECTION FROM DESIGN TOE OF SLOPE TO TOE OF KEY AS SHOWN ON AS BUILT "D > m m o I cn NATURAL SLOPE TO BE RESTORED WITH COMPACTED FILL BACKCUT VARIES |iW?rj7. MINIMUM 15* MINIMUM KEY WIDTH 2*X 3* MINIMUM KEY DEPTH 2'MINIMUM IN BEDROCK OR APPROVED MATERIAL BENCH WIDTH MAY VARY * « "^'.MINIMUM NOTE: 1. WHERE THE NATURAL SLOPE APPROACHES OR EXCEEDS THE DESIGN SLOPE RATIO. SPECIAL RECOMMENDATIONS WOULD BE PROVIDED BY THE SOILS ENGINEER. 2, THE NEED FOR AND DISPOSITION OF DRAINS WOULD BE DETERMINED BY THE SOILS ENGINEER BASED UPON EXPOSED CONDITIONS. RLL OVER CUT DETAIL H nUT/RLL CONTACT 1. AS SHOWN ON GRADING PLAN 2. AS SHOWN ON AS BUILT ORIGINAL TOPOGRAPHY MAINTAIN MINIMUM 15* RLL SECTION FROM BACKCUT TO FACE OF RNISH SLOPE CUT SLOPE ^^^^ BEDROCK OR APPROVED MATERIAL LOWEST BENCH WIDTH 15* MINIMUM OR H/2 BENCH WIDTH MAY VARY r- > m m o I NOTE: THE CUT PORTION OF THE SLOPE SHOULD BE EXCAVATED AND EVALUATED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST PRIOR TO CONSTRUCTING THE FILL PORTION. STABILIZATION FILL FOR UNSTABLE MATERIAL EXPOSED IN PORTION OF CUT SLOPE TJ r- > m m o I oo %lPnSFn FINISHED GRADE '^^^y/^/ UNWEATHERED BEDROCK OR APPROVED MATERIAL ^^^^OMPACTED STABILIZATION RLL •MINIMUM TILTED BACK IF RECOMMENDED BY THE SOILS ENOINEER AND/OR ENGINEERING GEOLOGIST. THE REMAINING CUT PORTION OF THE SLOPE MAY REQUIRE REMOVAL AND REPLACEMENT WITH COMPACTED RLL NOTE: 1. SUBDRAINS ARE NOT REQUIRED UNLESS SPECIFIED BY SOILS ENOINEER AND/OR ENGINEERING GEOLOGIST, 2 -Wr SHALL BE EQUIPMENT WIDTH (15'l FOR SLOPE HEIGHTS LESS THAN 25 FEET. FOR SLOPES GREATER' THAN 25 FEET "W" SHALL BE DETERMINED BY THE PROJECT SOILS ENGINEER AND /OR ENGINEERING GEOLOGIST. AT NO TIME SHALL 'W BE LESS THAN H/2. SKIN FILL OF NATURAL GROUND ORIGINAL SLOPE 2'MINIMUMj^ _r-<^^jg?^ | KEY DEPTH ^/V^ 15'MfNIMUM KEY WIDTH ROPOSED FINISH GRADE 15* MINIMUM TO BE MAINTAINED FROM PROPOSED RNISH SLOPE FACE TO BACKCUT PROPOSED FINISH SLOPE xS^y^ ^//^/^ BEDROCK OR APPROVED MATERIAL ^ 3'MINIMUM KEY DEPTH m m o I CD NOTE: 1. THE NEED AND DISPOSITION OF DRAINS WILL BE DETERMINED! BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST BASED ON FIELD CONDITIONS. 2 PAD OVEREXCAVATION AND RECOMPACTION SHOULD BE PERFORMED IF DETERMINED TO BE NECESSARY BY THE SOILS ENOINEER AND/OR ENGINEERINO GEOLOGIST. DAYLIGHT CUT LOT DETAIL RECONSTRUCT COMPACTED RLL SLOPE AT 2:1 OR FLATTER (MAY INCREASE OR DECREASE PAD AREA). OVEREXCAVATE AND RECOMPACT REPLACEMENT RLL AVOID AND/OR CLEAN UP SPILLAGE OF MATERIALS ON THE NATURAL SLOPE LANKET RLL <^/^ <^^y^^^T^ BEDROCK OR APPROVED MATERIAL TYPICAL BENCHINO ORADIENT„,> r- > m m o I MOTE: 1. SUBORA.N AND KEY WIDTH REaUIREMENTS WILL BE DETERMINED BASED ON EXPOSED SUBSURPACE CONDITIONS AND THICKNESS OF OVERBURDEN. „^T.ou,„cn NFrESSARY BY 2. PAD OVER EXCAVATION AND RECOMPACTION SHOULD BE PERFORMED IF DETERMINED NECESSARY THE SOILS ENGINEER AND/OR THE ENGINEERING GEOLOGIST. TRANSITION LOT DETAIL CUT LOT (MATERIAL TYPE TRANSITION) NATURAL GRADE COMPACTED RLL OVEREXCAVATE AND RECOMPACT ^J5J5^^ MINIMUM* ^ UNWEATHERED BEDROCK OR APPROVED MATERIAL TYPICAL BENCHING CUT-FILL LOT (DAYUGHT TRANSITION) PAD GRADE NATURAL GRADE '^'^ 5'MINIMUM OVEREXCAVATE AND RECOMPACT /j^m^ww^W^^^^' ^^^^^^^ UNWEATHERED BEDROCK OR APPROVED MATERIAL TYPICAL BENCHING NOTE: * DEEPER OVEREXCAVATION MAY BE RECOMMENDED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST IN STEEP CUT-RLL TRANSITION AREAS. PLATE EG-11 SETTLEMENT PLATE AND RISER DETAIL 2'X 2'X 1/A" STEEL PLATE STANDARD 3/A- PIPE NIPPLE WELDED TO TOP OF PLATE. 3/A" X 5* GALVANIZED PIPE. STANDARD PIPE THREADS TOP AND BOTTOM, EXTENSIONS THREADED ON BOTH ENDS AND ADDED IN 5" INCREMENTS. 3 INCH SCHEDULE AO PVC PIPE SLEEVE, ADD IN 5'INCREMENTS WITH GLUE JOINTS. RNAL GRADE MAINTAIN 5'CLEARANCE OF HEAVY EQUIPMENT, MECHANICALLY HAND COMPACT IN 2*VERTICAL -rV LIFTS OR ALTERNATIVE SUITABLE TO AND J ACCEPTED BY THE SOILS ENGINEER. MECHANICALLY HAND COMPACT THE INITIAL 5' VERTICAL WITHIN A 5* RADIUS OF PLATE BASE. BOTTOM OF CLEANOUT PROVIDE A MINIMUM V BEDDING OF COMPACTED SAND NOTE: 1. LOCATIONS OF SETTLEMENT PLATES SHOULD BE CLEARLY MARKED AND READILY VISIBLE (RED FLAGGED) TO EQUIPMENT OPERATORS. 2 C0NT^(:T0R SHOULD MAINTAIN CLEARANCE OF A 5'RADIUS OF PLATE BASE AND KN 5- (VERTI^^^^^^ EQUIPMENT. RLL BE HAND-COMPACTED TO PROJECT SPECIRCATIONS OR COMPACTED BY ALTERNATIVE APPROVED BYTHE SOILS ENGINEER. ^ .......r.... A .r.=Ani..e 3. AFTER 5'(VERTICAL) OF RLL IS IN PLACE. CONTRACTOR SHOULD MAINTAIN A 5_JRADIUS EQUIPMENT CLEARANCE FROM RISER. A. PLACE AND MECHANICALLY HAND COMPACT INITIAL 2'OF RLL PRIOR TO ESTABLISHING THE INITIAL READING. 5. IN THE EVENT OF DAMAGE TO THE SETTLEMENT PLATE OR EXTENSION RESULTING FROM EQUIPMENT OPERATING WITHIN THE SPECIFIED CLEARANCE AREA. CONTRACTOR SHOULD IMMEDIATELY NOTIFY THE SOILS ENGINEER AND SHOULD BE RESPONSIBLE FOR RESTORING THE SETTLEMENT PLATES TO WORKING ORDER. 6. AN ALTERNATE DESIGN AND METHOD OF INSTALLATION MAY BE PROVIDED AT THE DISCRETION OF THE SOILS ENGINEER. PLATE EG-U TYPICAL SURFACE SETTLEMENT MONUMENT RNISH GRADE 3-6' DIAMETER X 3 1/2'LENGTH HOLE 3/8" DIAMETER X B" LENGTH CARRIAGE BOLT OR EQUIVALENT CONCRETE BACK RLL PLATE EG-15 TEST PIT SAFETY DIAGRAM SIDE VIEW ( NOT TO SCALE 1 TOP VIEW 100 FEET APPROXIMATE CENTER OF TESTPIT 1 NOT TO SCALE ) PLATE EG-16 OVERSIZE ROCK DISPOSAL VIEW NORMAL TO SLOPE FACE OO 20'MINIMUM oo oo J5* MINIMUM (AJL^ *r MINIMUM (C) oo PROPOSED FINISH GRADE MINIMUM (E) CP 15* MINIMUM (A) oo CX) (G) C50 cxaU=) BEDROCK OR APPROVED MATERIAL VIEW PARALLEL TO SLOPE FACE PROPOSED FINISH GRADE FROM _ MINIMUM <C) BEDROCK OR APPROVED MATERIAL NOTE: (A) (B) (C) ID) (E) (R IG) ONE EQUIPMENT WIDTH OR A MINIMUM OF 15 FEET. HEIGHT AND WIDTH MAY VARY DEPENDING ON ROCK SIZE AND TYPE OF EQUIPMENT. LENGTH OF WINDROW SHALL BE NO GREATER THAN 100'MAXIMUM. IF APPROVED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST. WINDROWS MAY BE PLACED DIRECTLY ON COMPETENT MATERIAL OR BEDROCK PROVIDED ADEQUATE SPACE IS AVAILABLE FOR COMPACTION, ORIENTATION OF WINDROWS MAY VARY BUT SHOULD BE AS RECOMMENDED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST. STAGGERING OF WINDROWS IS NOT NECESSARY UNLESS RECOMMENDED. CLEAR AREA FOR UTILITY TRENCHES. FOUNDATIONS AND SWIMMING POOLS. ALL FILL OVER AND AROUND ROCK WINDROW SHALL BE COMPACTED TO 9 0% RELATIVE COMPACTION OR AS RECOMMENDED. AFTER FILL BETWEEN WINDROWS IS PLACED AND COMPACTED WITH THE LIFT OF FILL COVERING WINDROW. WINDROW SHOULD BE PROOF ROLLED WITH A D-9 DOZER OR EQUIVALENT. VIEWS ARE DIAGRAMMATIC ONLY. ROCK SHOULD NOT TOUCH AND VOIDS SHOULD BE COMPLETELY RLLED IN. PLATE RD"" 1 ROCK DISPOSAL PITS VIEWS ARE DIAGRAMMATIC ONLY. ROCK SHOULD NOT TOUCH AND VOIDS SHOULD BE COMPLETELY RLLED IN. RLL LIFTS COMPACTED OVER ROCK AFTER EMBEDMENT GRANULAR MATERIAL COMPACTED RLL SIZE OF EXCAVATION TO BE COMMENSURATE WITH ROCK SIZE ROCK DISPOSAL LAYERS GRANULAR SOIL TO RLL VOIDS. DENSIRED BY FLOODING LAYER ONE ROCK HIGH V ^OMPACTED RLL Jo-PROPOSED RNISH GRADE MINIMUM OR BELOW LOWEST UTIU OVERSIZE LAYER ^ ^ COMPACTED FILL PROFILE ALONG LAYER LOPE FACE MINIMUM OCXD0000C0COC5COC=OO=ac^ CLEAR ZONE 20'MINIMUM LAYER ONE ROCK HIGH PLATE RD-2