The URL can be used to link to this page

Home My WebLink AboutCT 03-13; BLACK RAIL RIDGE; PRELIMINARY GEOTECHNICAL EVALUATION; 2003-09-03"!-' ~j~.~' ',1'" ~,~ >J' • ("r", • ~,' ,', -'j • . ~ )". " ~ . ~ . • ~ \ r ! i .... ,.. ' .... 1.' , V ~ .~ ~ '" I •• " " ,~ . ~:'.:, ~, . '. ~ " . ,,':"'-. : ' ;.~, -. -:-" I' ';- ,'\', .'; " . ,,'., .' . ". ,~ . ". - " , . " .'.,. , , ' ", .~- ., .~ .. ' .. .'.' ? '.,' .,' ) 1.: .. ' " '" . ""~ '" " '.: ' " " j. ~ [ :-' ' .,r .1"., .. ~ j,_~ 1 -". : 'j : ',,\" .. ' '. ~ . . " ' ~ .' j".'t,": ' .. " ~ : ~, :-, ~' .... ,.' , , '.~ ~ . ,'.: --.. _ .. Geotechnical • Geologic • Environmental 5741 Palmer Way • Carlsbad, California 92008 • (760) 438-3155 • FAX (760) 931-0915 Pacific Coast Development 567 San Nicolas Drive, Suite 130 Newport Beach, California 92660 Attention: Mr. Brett Shaves September 3, 2003 W.O.4015-A-SC Subject: Preliminary Geotechnical Evaluation, Black Rail RidgeAPN 215-070-33, City of Carlsbad, San Diego County California. Dear Mr. Shaves: 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 of the available data (see Appendix A), fi~ld exploration, laborc;ttory testing, geologic and engineering analysis, development of the property appears to be feasible from a geotechnical viewpoint, provided the recommendations presented in the text of this report are properly incorporated into the design and construction ofthe project. The most significant elements of this study are summarized below: • Based on the Tentative Map provided by M.L.B. Engineering, Inc., it appears thatthe proposed development will consist of the preparation of 11 relatively level building pads for the construction of single-family residences, with associated infrastructure (Le. underground utilities, streets, etc.). It appears that sewage disposal will be tied into the municipal system. The need for import soils is unknown at this time. • All deleterious debris and vegetation should be removed from the site and properly- disposed of, should settlement sensitive improvements be proposed within their influence. Removals of compressible undocumented artificial fill, colluvial soils, and weathered Quaternary Terrace Deposits will be necessary prior to fill placement. Depths of removals are outlined in the "Conclusions and Recommendations" section of this report. In general, removals will be on the order of 1 to 3 feet across a majority of the site. However, localized deeper removals cannot .be precluded. • To provide for a uniform minimum 3-foot compacted fill blanket, overexci;lvation of the terrace deposits to a depth of 3 feet below finish ,pad grade elevation is recommended. If proposed footings or isolated pad footings are deeper than 24 inches below finish pad grade elevation, additional overexcavation will be necessary to provide a minimum 18 inches of compacted fill beneath the footing. • Maximum to minimum fill thickness below the foundation elements ofthe structures should not exceed a ratio of 3:1 (maximum:minimum). • Based on site conditions and planned improvements, fill slopes up to ±20 feet in height and cut slopes up to ±9 feet in height are proposed. • The expansion potential of tested onsite soils is low (Expansion Index [E.!.] 21 to 50). However the potential for medium expansive soil exposed at finish grade cannot be precluded Conventional foundations may be utilized for these soil conditions. Post-tension foundation recommendations can be provided upon request. • Laboratory Testing indicates that site soils present a negligible sulfate exposure to concrete and are corrosive to ferrous materials when saturated; however, it is our understanding that standard concrete cover is usually sufficient for mitigation. • Perched water was observed during the field investigation but is not expected to be a major factor in development of the site. However, due to the nature of the site materials, seepage and/or perched groundwater conditions may develop throughout the site along boundaries of contracting permeabilities (Le., fill/terrace deposit contacts), and should be anticipated. • Our evaluation indicates that the site has a very low potential for liquefaction. Therefore, no recommendations for mitigation are deemed necessary. • The seismic acceleration values and design parameters provided herein should be considered during the design of the proposed development. • Our evaluation indicates there are no known active faults crossing the site. • 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. Pacific Coast Development File:e:\wp9\4000\4015a.pge GeoSoils, Ine. W.O.401S-A-SC Page Two 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 undersigned. Respectfully submitted, GeoSoils, Inc. ~o Ry n Boehmer - Staff Geologist RB/JPF/DWS/jh/jk. Distribution: (4) Addressee Pacific Coast Development File:e:\wp9\4000\4015a.pge GeoSoils, Ine. W.O.4015-A-SC Page Three ,..---------------------------------------1 TABLE OF CONTENTS SCOPE OF SERVICES .................................................... 1 SITE CONDITIONS/PROPOSED DEVELOPMENT .............................. 1 SITE EXPLORATION ..................................................... 3 REGIONAL GEOLOGY ................................................... 3 SITE GEOLOGIC UNITS .................................................. 3 Artificial Fill (Non-structural) .......................................... 3 Topsoil/Colluvium (Not Mapped) ...................................... 4 Quaternary-age Terrace Deposits (Map Symbol-Qt) ..................... 4 FAULTING AND REGIONAL SEISMICITY ..................................... 4 Regional Faults .................................................... 4 Seismicity ........................................................ 6 Seismic Shaking Parameters ......................................... 7 Seismic Hazards ................................................... 8 LIQUEFACTION ......................................................... 8 Paleoliquefaction Features ........................................... 9 GROUNDWATER ........................................................ 9 SLOPE STABILITY ....................................................... 9 LABORATORY TESTING ................................................. 10 General ......................................................... 10 Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Moisture-Density Relations ......................................... 10 Laboratory Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Expansion Potential ............................................... 11 Direct Shear Test .................................................. 11 Atterberg Limits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Corrosion/Sulfate Testing ............................... '." ......... 12 CONCLUSIONS ................................................. '.' ..... 12 General .......................................................... 12 EARTHWORK CONSTRUCTION RECOMMENDATIONS ....................... 14 .' . General ......................................................... 14 Site Preparation ................................................... 14 Removals (Unsuitable Surficial Materials) .............................. 14 Fill Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Transitions/Overexcavation ......................................... 15 GeoSoils, Ine. SUBDRAINS ........................................................... 15 RECOMMENDATIONS -FOUNDATIONS .................................... 15 Preliminary Foundation Design ...................................... 15 Bearing Value .............................................. 16 Lateral Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Foundation Settlement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Footing Setbacks ................................................. 17 Construction ......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Low Expansion Potential (E.!. 21 to 50) .......................... 17 Medium Expansion Potential (E.I. 51 to 90) ....................... 18 CORROSION ........................... : ...................... ' ........ 19 UTILITIES ............................................................. 19 WALLS AND RETAINING WALLS .......................................... 20 General ......................... ' ................................ 20 Restrained Walls .............................. ' .................... 20 Cantilevered Walls .......................................... ; ..... 20 Wall Backfill and Drainage .......................................... 21' Wall Footing Transitions ............................................. 21 Top of Slope/Perimeter Walls ....................................... 22 Footing Excavation Observation ..................................... 22 EXTERIOR FLATWORK ......................................... ,' ........ 22 DEVELOPMENT CRITERIA ......... ; ..................................... 23 Slope Deformation ................................................ 23 Slope Maintenance and Planting ..................................... 24 Drainage ........................................................ 24 Erosion Control ................................................... 25 Landscape Maintenance ........................... : ............... 25 Gutters and Downspouts ........................................... 25 Subsurface and Surface Water ...................................... 26 Site Improvements ................................................ 26 Tile Flooring ..................................................... 26 Additional Grading ................................................ 26 Footing Trench Excavation ......................................... 27 Trenching ....................................................... 27 Utility Trench Backfill .............................................. 27 SUMMARY OF RECOMMENDATIONS REGARD!NG GEOTECHNICAL OBSERVATION AND TESTING ........................................................ 28 Pacific Coast Development File:e:\wp9\4000\4015a.pge GeoSoils,lne. Table of Contents Pageii OTHER DESIGN PROFESSiONALS/CONSULTANTS .......................... 28 PLAN REVIEW ......................................................... -29 LIMITATIONS .......................................................... 29 FIGURES: Figure 1 -Site Location Map ......................................... 2 Figure 2 -California Fault Map ........................................ 5 ATTACHMENTS: Appendix A -References .................................... Rear of Text Appendix 8 -Test Pit Logs .................................. Rear of Text Appendix C -EQFAULT, EQSEARCH, AND FRISKSP ............ Rear of Text Appendix D -Laboratory Data ............................... Rear of Text Appendix E -General Earthwork and Grading Guidelines ......... Rear of Text Plate 1 -Geotechnical Map ......................... Rear of Text in Folder Pacific Coast Development File:e:\wp9\4000\4015a.pge GeoSoils, Ine. Table of Contents Page iii PRELIMINARY GEOTECHNICAL EVALUATION BLACK RAIL RIDGE, APN 215-070-33, CITY OF 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 (see Appendix A). 2. Geologic site reconnaissance, subsurface exploration with exploratory test pit excavations (see Appendix B), sampling, and mapping. 3. General areal seismicity evaluation (see Appendix C). 4. Appropriate laboratory testing of representative soil samples (see Appendix D). 5. Engineering and geologic analysis of data collected. 6. Preparation of this report. SITE CONDITIONS/PROPOSED DEVELOPMENT The subject site is an irregularly shaped property located on the southwest corner of the intersection of Black Rail Road and Poinsettia Lane in the City of Carlsbad, California. The property slopes to the northwest at a gradient of about 8: 1 (horizontal :vertical), or flatter. An approximately 15-foot high (maximum) fill slope is located on the northern margin of the property that was probably constructed for Poinsettia Lane. Site drainage is by sheet flow runoff, apparently directed toward the northwest. The site is currently being utilized as a nursery. Based on the Tentative Map provided by M.L.B. Engineering, it appears that proposed development will consist of preparing 11 relatively level pads for the construction of single-family residences, utilizing wood frames and slabs-on-grade and associated infrastructure (i .e. underground utilities, street, etc.). It appears that cut and fill grading techniques will be utilized to bring the site to design grades. Fill slopes up to ±20 feet in height and cut slops up to +9 feet in height are proposed. Building loads are assumed to be typical for this type of relatively light construction. It is anticipated that sewage disposal will be tied into the municipal system. The need for import soils is unknown at this time. GeoSoils, Ine. I Base MalJ: The Thomas Guide, San Diego Count~ Street GUide and Directory, 2003 Edition, by Thomas Bros. Maps, page 1127, 1":1/2 mile .... . N Rt.produced with p.rmlaalon granted bV Thoma. 8to •• Map •• Thl. map I. 'copyrlghted by Tllom •• Braa. M.pI. It I. unlawful to OOP1 or repreduc. all or any part thereof, whethe, for peraonal 118e o~ resale, wlthollt permission. All rights reserved. . W.O. 4015-A-SC SITE LOCATION MAP Figure 1 SITE EXPLORATION Surface observations and subsurface explorations were performed on August 18, 2003, by a representative of this office. A survey of line and grade for the subject lot was not conducted by this firm at the time of bur site reconnaissance. Near surface soil conditions were explored with six test pit excavations within the site to evaluate soil and geologic conditions. The approximate locations of each test pit are shown on the attached Geotechnical Map (see Plate 1). Test Pit Logs are presented in Appendix B. . 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 northwesterly. 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 County 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 of the 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 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. SITE GEOLOGIC UNITS The site geologic units encountered during our subsurface investigation and site reconnaissance included undocumented artificial fill, colluvium/topsoil, and Quaternary-age Terrace Deposits. The earth materials are generally described belowfrom the youngest to the oldest. The distribution of these materials is shown on Plate 1. Artificial Fill (Non-structural) Non-structural artificial fill was observed to mantle the site in all ofthe test pit excavations. The encountered non-structural artificial fill consists of yellow brown to dark red brown to light brown silty sands that are dry to moist and loose to medium dense and porous. Varying amounts of deleterious debris were also ·observed. These materials are considered potentially compressible in their existing state and will require removal and recompaction if settlement sensitive structures are proposed within their influence. Pacific Coast Development Black Rail Ridge, APN 215-070-33 File:e:\wp9\4000\4015a.pge GeoSoils, lne. W.O.4015-A-SC September 3, 2003 . Page 3 Topsoil/Colluvium (Not Mapped) Topsoil/colluvium was observed to directly underlie the artificial fill in a majority of the test' pits, and consists of dark red brown to red brown, moist to saturated,loose to medium dense, porous silty sands, and sands with some silt that are approximately ± % to ± 1 % feet thick. These materials are considered potentially compressible in their eXisting state and will require removal and recompaction if settlement sensitive structures are proposed within their influence. Quaternary-:age Terrace Deposits (Map Symbol -Qt) Quaternary-age terrace deposits were observed to underlie the site, and consist of stiff sandy clays, dense clayey sands, and very dense silty sands and sands with silt. These deposits are generally light brown to orange to brown to light gray to yellow brown and dry to wet. The upper ± 1-foot of these sediments are generally weathered and considered unsuitable for structural support in its present condition, and should be removed and recompacted or processed in place. Bedding structure was not readily observed, but regionally is typically flat lying to sub-horizontal. These sediments are typically massive to weakly bedded. Terrace deposits encountered along the southern and western portions of the site possessed a discontinuous, well cemented hardpan. Based on our experience with other projects in the immediate vicinity, this hardpan is believed to be on the order of ± 1 to ±2 feet thick, and most likely will present difficulty during underground utility excavations if relatively light equipment (Le. rubber-tire backhoe) is used. However, the hardpan is generally considered to be rippable with heavy grading equipment (0-9 or equivalent). FAULTING AND REGIONAL SEISMICITY Regional Faults Our review indicates that there are no known active faults crossing this site within the area proposed for development, and the site is not within an Earthquake Fault Zone (Hart and Bryant, 1997). However, the site is situated in an area of active as well as potentially active faulting. These 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. Major active fault zones that may have a significant affect on the site, should they experience activity, are listed in the following table (modified from Blake, 2000a): Pacific Coast Development Black Rail Ridge, APN 215-070-33 File:e:\wp9\4000\4015a.pge GeoSoils, Inc. W.O.4015-A-SC September 3, 2003 Page 4 CALIFORNIA FAULT MAP PACIFIC COAST DEVELOPMENT 1100~----------------------------------------------~ 1000 900 800 700 600 500 400 300 200 100 a -100~~~~~~~~~~~~J4~~~~~~~~JJ~JJ~ -400 -300 -200 -100 a 100 200 300 400 500 600 W.O.4015-A-SC Figure 2 GeoSoils, Inc. .. 4a .. ~ APPROXIMATE DISTANCE ABBREVIATED FAULT NAME MILES (KM) Newport-Inglewood (Offshore) 5.7 (9.2) Rose Canyon 5.7 (9.2) Coronado Bank 21.7 (34.9) Elsinore-Temecula 23.5 (37.9) Elsinore-Julian 23.8 (38.3) Elsinore-Glen Ivy 33.1 (53.2) Palos Verdes 35.e (57.6) Earthquake Valley 43.7 (70.4) Newport-Inglewood (L.A. Basin) 45.7 (73.5) San Jacinto-Anza 46.1 (74.2) San Jacinto-San Jacinto Valley 46.5 (74.9) Chino-Central Ave. (Elsinore) 47.2 (75.9) Seismicity The acceleration-attenuation relations of Bozorgnia, Campbell, and Niazi (1999) Horizontal, Soft Rock Uncorrected PGA, Campbell and Bozorgnia (1997 Revised) Soft Rock, and Bozorgnia, Campbell, and Niazi (1999) Horizontal Soft Rock. Corrected PGA Horizontal-Random have been incorporated into EQFAULT (Blake, ~OOOa). Forthisstudy, peak horizontal ground accelerations anticipated at the site were determined based on the random mean plus 1 sigma attenuation curve developed by Joyner and Boore (1982a and 1982b), Sadigh et al. (1987),and Bozorgnia et al. (1999). EOFAULT 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 any of at least 30 user-selected acceleration-attenuation relations that are contained in EOFAUL T. Based on the EOFAULT program, peak horizontal ground accelerations from an upper bound event at the site may be on the order of 0.52g to 0.61 g. The .c,omputer printouts of portions of the EOFAULT program are included within Appendix c. Pacific Coast Development Black Rail Ridge, APN 215-070-33 Fife:e:\wp9\4000\4015a.pge GeoSoils, Inc. W.O. 4015-A-SC September 3, 2003 Page 6 Historical site seismicity was evaluated with the acceleration-attenuation relations of Campbell and Bozorgnia (1997 Revised) 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 to 2002. 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 to 2002 was 0.33g. 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 the EQSEARCH program are presented in Appendix C. A probabilistic seismic hazards analyses was performed using FRISKSP (Blake, 2000c), which models earthquake sources as 3-D planes and evaluates the site specific probabilities of exceedance for given peak acceleration levels or pseudo-relative velocity levels. Based on a review of this data, and considering the relative seismic activity of the southern California region, a peak horizontal ground acceleration ofO.27g 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). Computer printouts of the FRISKSP program are included in Appendix C. Seismic Shaking Parameters Based on the site conditions, Chapter 16 ofthe Uniform Building Code (UBC, International Conference of Building Officials [ICBO], 1997) seismic parameters are provided in the following table: 1997 UBC CHAPTER 16 TABLE NO.' Seismic Zone (per Figure 16-2*) Seismic Zone Factor (per Table 16-1*) Soil Profile Type (per Table 16-J*) Seismic Coefficient Ca (per Table 16-Q*) Seismic Coefficient Cy (per Table 16-R*) Near Source Factor Na (per Table 16-S*) Near Source Factor Ny (per Table 16-T*) Distance to Seismic Source Pacific Coast Development Black Rail Ridge, APN 215-070-33 File:e:\wp9\4000\4015a.pge .. -.-, GeoSoils, Ine. SEISMIC PARAMETERS 4 0.40 SD 0.44Na 0.64Ny 1.0 1.19 5.7 mi (9.2 km) W.O.4015-A-SC September 3, 2003 Page 7 , 1997 UBC CHAPTER 16 TABLE NO. SEISMIC PARAMETERS Seismic Source Type (per Table 16-U*) B Upper Bound Earthquake (Rose Canyon fault) Mw 6.9 * Figure and Table references from Chapter 16 of the Uniform Building Code (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: • Dynamic Settlement • Surface Fault Rupture • Ground Lurching or Shallow Ground Rupture • Seiche It is important to keep in perspective that in the event of a maximum probable or credible earthquake occurring on any ofthe 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. LIQUEFACTION 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. Liquefaction susceptibility is related to numerous factors and the following conditions should be 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 Pacific Coast Development Black Rail Ridge, APN 215-070-33 File:e:\wp9\4000\4015a.pge GeeSeits,lne. W.O.4015-A-SC September 3, 2003 Page 8 experience a seismic event of a sufficient duration and magnitude, to induce straining of soil particles. Inasmuch as at least one or two ofthe necessary concurrent conditions listed above do not have the potential to affect the site, it is our opinion that liquefaction does not" pose a significant constraint to development. Paleoliguefaction Features Paleoliquefaction features ("sand blows," sand filled fissures and injection dikes, sand vents, etc.) were not noted during our field investigation but were observed by GSI during the grading operations for a nearby site. As stated above, the potential for liquefaction and associated surface manifestation at tbe site is considered to be very low, provided that the recommendations presented in this report are incorporated into the design and construction ofthe project. These features are related to paleo seismic activity and should be mitigated during site grading provided that each lot contains a minimum 3-foot thick compacted fill blanket. GROUNDWATER Perched water was encountered in our test pit number 5 at ~ 1 Y2 feet below the existing grade. The perched water table appears to be confined between the overlying colluvial soils and the underlying terrace deposit hardpan due to a contrast in permeability between the colluvial soils and the terrace deposits. The perched water is most likely derived from irrigation water that cannot percolate through the very dense terrace deposit hardpan and appears to travel down gradient through the porous colluvial soils. Subsurface water may be a nuisance but is not anticipated to adversely affect site development, provided that the recommendations contained in this report are incorporated into final design and construction. However, the necessity for subdrain systems cannot be precluded and should be anticipated. These observations reflect site conditions at the time 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. Perched groundwater conditions along fill/bedrock contacts, and 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. SLOPE STABILITY Based on our evaluation and experience on similar projects, proposed cut and fill slopes constructed using onsite materials, to heights up to "±20 feet, should be grossly and surficially stable provided the recommendations contained herein are implemented during site planning and development. The terrace deposits mapped during our field investigation Pacific Coast Development Black Rail Ridge, APN 215-070-33 File:e:\wp9\4000\4015a.pge GeoSoils, Inc. W.O.4015-A-SC September 3, 2003 , Page 9 were relatively massive and it has been our experienc~ that the terrace deposits exhibit subhorizontal bedding on a regional scale. These conditions do not suggest a potential for slope instability. However, geologic structure should be further evaluated during actual site earthwork to assess bedrock structure relative to actual slope locations and configurations. Although unlikely, if adverse geologic structures are encountered, supplemental recommendations and earthwork may be warranted. A more detailed slope stability analysis will be necessary when final site development plans have been prepared. LABORATORY TESTING General Laboratory tests were performed on representative samples of the onsite earth materials in order to evaluate their physical characteristics. The test procedures used and results obtained are presented below. Classification Soils were classified visually according to the Unified Soils Classification System. The soil classifications are shown on the Test Pit Logs in Appendix B. Moisture-Density Relations The field moisture contents and dry unit weights were determined for selected undisturbed samples in the laboratory. The dry unit weight was determined in pounds per cubic foot (pct) , and the field moisture content was determined as a percentage ofthe dry weight. The results of these tests are shown on the test pit logs in Appendix B. Laboratory Standard The maximum dry density and optimum moisture content was determined for the major soil type encountered in the test pits. The laboratory standard used was ASTM D-1557. The moisture-density relationship obtained for this soil is shown below: SOIL TYPE TEST PIT Yellow Brown TP-3 Clayey SAND (Composite) Pacific Coast Development Black Rail Ridge, APN 215-070-33 File:e:\wp9\4000\4015a.pge MAXIMUM DRY DENSITY (pet) . 127.0 GeoSoils, Inc. . ' OPTIMUM MOISTURE . CONTENT (%) . 10.5 W.O.4015-A-SC September 3, 2003 Page 10 Expansion Potential Expansion testing was performed on a representative samples of site soil in accordance with usc Standard 18-2. The results of expansion testing are presented in the following table. LOCATION TP-3 @ 0-3' (Composite) Direct Shear Test EXPANSION INDEX EXPANSION POTENTI 21 Low Shear testing was performed on a representative, "remolded" sample of site soil in general accordance with ASTM Test Method 0-3080 in a Oirect Shear Machine of the strain control type. The shear test results are presented as follows and are provided as Plate 0-1 in Appendix 0: .: ' RESIDUAL :.-: ': .. :: : PRIMARY SAMPLE LOCATION F========9r=============*==========r TP-3@0-3' (Composite) Atterberg Limits COHESION (PSF) 141 FRICTION ANGLE {DEGREES} 27 COHESION (PSF) 126 27 . Test was performed on a selected representative fine grained soil sample to evaluate the liquid limit, plastic limit and plasticity index in general accordance with ASTM 04318-64. The test result is presented in the following table and as Plate 0-2 in Appendix D. LOCATION TP-3@0-3' (Composite) Pacific Coast Development Black Rail Ridge, APN 215-070-33 File:e:\wp9\4000\4015a.pge LIQUID LIMIT PLASTIC LIMIT, 30 18 GeoSoils, Ine. PLASTICITY INDEX 12 W.O.4015-A-SC September 3, 2003 . Page 11 Corrosion/Sulfate Testing GSI conducted sampling of onsite materials for soil corrosivity on the subject project. Laboratory test results were completed by M.J. Schiff & Associates (consulting corrosion engineers). The laboratory test results, presented in Appendix D should be utilized by the project structural engineer (or corrosion engineer) in their evaluation of site corrosivity mitigation measures. Test results indicate that site soils are very strongly acidic (pH=4.9) with respectto acidity and are corrosive to ferrous metals. Corrosive soils are considered to range between 1,000 and 2,000 ohms-cm. However, it is our understanding that standard concrete cover is usually sufficient mitigation for corrosive soils. Site soils have a negligible corrosion potential to concrete across the entire site (UBCrange for negligible sulfate exposure is 0.00 to 0.10 percentage by weight soluble [S04] in soil). Alternative methods and additional comments may be obtained from a qualified corrosion engineer Test results are presented as Plate D-3 in Appendix D. ' CONCLUSIONS General Based on our field exploration, laboratory testing, and geotechnical engineering analysis, it is our opinion that the site appears suitable for the proposed development from a geotechnical engineering and geologic viewpoint, provided that the recommendations presented in the following sections are incorporated into the design and construction 'phases of site development. The primary geotechnical concerns with respect to the proposed development are: • Depth to competent material. • Overexcavation of streets and pads. • Potential for perched groundwater after development • Expansion and corrosion potential of site soils. • Slope stability. • Regional seismic activity. The recommendations presented herein consider these as well as other aspects ofthe site. The engineering analyses performed concerning site preparation and the recommendations presented herein have been completed using the information provided and obtained during our field work. In the event that any significant Qhanges are made to proposed site development, the , , conclusions and recommendations contained in this report shall not be considered valid unless the changes are reviewed and the recommendations of this report verified or Pacific Coast Development Black Rail Ridge, APN 215-070-33 Fife:e:\wp9\4000\4015a.pge GeoSoils, Ine. W.O.4015-A-SC September 3, 2003 Page 12 modified in writing by this office. Foundation design parameters are considered preliminary until the foundation design, layout, and structural loads are provided to this office for review. 1. Soil engineering, observation, and testing services should be provided during grading to aid the contractor in removing unsuitable soils and in his effort to compact the fill. "" 2. Geologic observations should be performed during grading to verify and/or further evaluate geologic conditions. Although unlikely, if adverse geologic structures are encountered, supplemental recommendations and earthwork may be warranted. 3. Existing undocumented artificial fill on the order of ± % to ± 1% feet thick, colluvial soils to depths ranging from ± 1% to ±3 feet, and the upper ± 1 foot ofthe weathered terrace deposits are considered unsuitable "for the support of settlement-sensitive structures in their present condition, based on current industry standards. These materials are potentially compressible in their present condition, and may be subject to differential settlement. Mitigation in the form of removal and recompaction will be necessary. 4. Due to the very dense nature of the hardpan encountered within some of the exploratory test pits, trenching for the placement of underground utilities, within the street areas, may be difficult to non-trenchable at relatively shallow depths with Iight-weighttrenching equipment (Le., rubber tire backhoe). Overexcavation to 1 foot below the lowest utility invert within the street right-of-way, during grading will better facilitate trenching for street utility improvements. However, this is not a geotechnical requirement. 5. In general and based upon the available data to date, perched groundwater may be a nuisance but is not expected to be a major factor in development of the site assuming shallow excavations. However, perched groundwater conditions along fill/terrace deposit contacts, and 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. In addition, subdrainage systems for the control of localized groundwater seepage should be anticipated. The proposed locations of such drains can be delineated at the grading plan review stage of planning. 6. Due to the non-cohesive nature of some of the onsite materials, some caving and sloughing may be anticipated to be a factor in subsurface excavations and trenching. Therefore, current local and state/federal safety ordinances for subsurface trenching should be enforced. Pacific Coast Development Black Rail Ridge, APN 215-070-33 File:e:\wp9\4000\4015a.pge GeoSoils, Ine. W.O.4015-A-SC September 3, 2003 Page 13 7. General Earthwork and Grading Guidelines are provided at the end of this report as Appendix F. Specific recommendations are provided below. 8. Our laboratory test results and experience on nearby sites related to expansion potential indicate that soils with lowto possibly medium expansion indices (locally) underlie the site. This should be considered during project design. Foundation design and construction recommendations are provided herein for low and medium expansion potential classifications. 9. The seismicity-acceleration values provided herein should be considered during the design of the proposed development. EARTHWORK CONSTRUCTION RECOMMENDATIONS General All grading should conform to the guidelines presented in Appendix Chapter A33 of the UBC, the requirements of the City of Carlsbad, and the Grading Guidelines presented in Appendix E, 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 (OSHA), and the Construction Safety Act should be met. Site Preparation All deleterious materials should be removed from the site prior to the start of construction. Removals (Unsuitable Surficial Materials) Due to the relatively loose/soft condition of the non-structural artificial fill, topsoil/colluvium, 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 to ±3 feet (including weathered terrace deposits) below existing grade should be anticipated throughout a majority of the site; however, locally deeper removals cannot be precluded and should be anticipated. Removals should be completed below a 1: 1 projection down and away from the edge of any settlement sensitive structure and/or limit of proposed fill. Once removals are completed, the exposed Pacific Coast Development Black Rail Ridge, APN 215-070-33 File:e:\wp9\4000\4015a.pge GeoSoils, Inc. W.O.4015-A-SC September 3, 2003 Page 14 bottom should be scarified in two perpendicular directions, moisture conditioned to at least optimum moisture content, and recompacted to 90 percent relative compaction. Fill Placement Subsequent to ground preparation, onsite soils may be placed in thin (±6 to a-inch) lifts, cleaned of vegetation and debris, brought to at least optimum moisture content, and compacted to achieve a minimum relative compaction of 90 percent. Iffill soil importation is planned, a sample of the soil import should be evaluated by this office prior to importing, in order to assure compatibility with the onsite soils and the recommendations presented in this report. At least three business days of lead time should be allowed by builders or contractors for proposed import submittals. This lead time will allow for particle size analysis, specific gravity, relative compaction, expansion testing, and blended import/native characteristics as deemed necessary. Import soils for a fill cap should be low expansive (Expansion Index [E.L] less than 50). The use of sub drains at the bottom ofthefill cap may be necessary, and subsequently recommended based on compatibility with onsite soils. Transitions/Overexcavation In order to provide for the uniform support of the proposed structures, a minimum 3-foot thick fill blanket is recommended for lots containing earth material transitions (Le. fill juxtaposed to terrace deposits). Any cut portion of a transition lot or lots with planned fills less than 3 feet should be overexcavated a minimum 3 feet below finish pad grade in order to provide for a minimum 3-foot compacted fiJI blanket. If proposed footings or isolated pad footings are deeper than 24 inches below finish pad grade elevation, additional overexcavation will be necessary to provide a minimum 18 inches of compacted fill beneath the footing. Maximum to minimum fill thickness below the foundation elements ofthe structures should not exceed a ratio of 3:1 (maximum:minimum). Consideration for overexcavation of the street right of ways to 1 foot below the lowest utility invert is recommended to better facilitate trenching for underground utilities. However, this is not a geotechnical requirement. SUBDRAINS Subdrainage systems for the control of localized perched water seepage should be anticipated. The proposed locations of such drains can be delineated at the 40-scale grading plan review stage of planning. RECOMMENDATIONS -FOUNDATIONS Preliminary Foundation Design In the eventthatthe information concerning the proposed development plans is not correct, or any changes in the design, location, or loading conditions of the proposed structures are Pacific Coast Development Black Rail Ridge, APN 215-070-33 File:e:\wp9\4000\4015a.pge GeoSoils, Ine. W.O.4015-A-SC September 3, 2003 . Page 15 ,. '! made, the conclusions and recommendations contained in this report are for the 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, GSJ 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, laboratory testing, and engineering analysis. Our review, field work, and recent laboratory testing indicates that onsite soils have a low expansion potential (E.1. = 21 to 50). Preliminary recommendations for foundation design and construction are presented below. Final foundation recommendations should be provided at the conclusion of grading, based on laboratory testing offill 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 (pst) 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 and connected by grade beam or tie beam in at least one direction. This value may be increased by 20 percent for each additional 12 inches in depth to a maximum value of 2,500 pst. 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 by the dead load. 2. Passive earth pressure may be computed as an equivalent fluid having a density of 250 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. Pacific Coast Development Black Rail Ridge, APN 215-070-33 File:e:\wp9\4000\4015a.pge W.O.4015-A-SC September 3, 2003 Page 16 GeoSoils, IDe. Foundation Settlement Foundation systems should be designed to accommodate a differential settlement of at least %-inch in a 40-foot span. Footing 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 of the footing to the descending slope face and no less than 7 feet, nor need 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 fo the wall. Alternatively, walls may be . designed to accommodate structural loads from buildings or appurtenances as described in the "Retaining Wall" section of this report. Alternatively, walls may be designed to accommodate structural loads from buildings or appurtenances as described in the Retaining Wall sections of this report. Construction The following foundation construction recommendations are presented as a minimum criteria from a soils engineering standpoint. The onsite soil expansion potential is generally low (E.I. 21 to 50) to possibly medium (E.1. 51 to 90). Recommendations for low and medium 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. Low Expansion Potential (E.I. 21 to 50) 1 . ' Exterior and interior footings should be founded at a minimum depth of 12 inches for one-story floor loads, and 18 inches for two-story floor loads, into compacted fill. Isolated column and panel pads, or wall footings, should be founded at a minimum depth of 18 inches into compacted fill. All footings should be reinforced with two NO.4 reinforcing bars, once placed near the top and one placed near the bottom of the footing. Footing widths should be as indicated in UBC (ICBO, 1997). 2. A grade beam, reinforced as above, and at least 12 inches square, should be provided across large (e.g., doorways) entrances. The base of the grade beam should be at the same efevation as the bottom of adjoining footings. Isolated, Pacific Coast Development Black Rail Ridge, APN 215-070-33 File:e:\wp9\4000\4015a.pge GeoSoils, Ine. W.O.4015-A-SC September 3, 2003 Page 17 exterior square footings should be tied within the main foundation in at least one direction with a grade beam. 3. Concrete slabs, where moisture condensation is undesirable, should be underlain with a vapor barrier consisting of a minimum of 10-mil polyvinyl chloride, or equivalent membrane, with all laps sealed. 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. Concrete slabs should be a minimum of 4 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 of the concrete .. IIHookingll of reinforcement is not considered an acceptable method of positioning the reinforcement. 5. Garage slabs 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. 6. Presaturation is not required for these soil conditions. The moisture content of the subgrade soils should be equal to, or greater than, optimum moisture content in the slab areas, prior to concrete placement. Medium Expansion Potential (E.I. 51 to 90) 1. Conventional continuous footings should be founded at a minimum depth of 18 inches below the lowest adjacent ground surface for one-or two-story floor loads into compacted fill. Interior footings may be founded at a depth,of 12 inches below the lowest adjacent ground surface. Footings for one-story floor loads should have a minimum width of 12 inches, and footings for two-story floor loads should have a minimum width of 15 inches. All footings should be reinforced with a minimum of two No.4 reinforcing bars at the top and two No.4 reinforcing bars at the bottom. Isolated interior and/or exterior piers and columns are not recommended. ' 2. A grade beam, reinforced as above, and at least 12 inches square, should be provided across the garage entrances. The base of the reinforced grade beam should be at the same elevation as the adjoining footings. ' 3. Concrete slabs in residential and garage areas should be underlain by a vapor barrier consisting of a minimum of 1 O-mil, polyvinyl-chloride membrane with all laps sealed. Two inches of the sand base should be' placed over the membrane to aid in uniform curing of the concrete and mitigate puncturing of the vapor barrier. Pacific Coast Development Black Rail Ridge, APN 215-070-33 File:e:\wp9\4000\4015a.pge GeoSoils, Ine. W.O.4015-A-SC September 3, 2003 Page 18 4. Concrete slabs, including garage areas, should be a minimum of 4 inches thick, and reinforced with No. 4 reinforcement bars placed on 18-inch centers, in two horizontally perpendicular directions (Le., long axis and short axis). All slab reinforcement should be supported to ensure proper mid-slab height positioning during placement of the concrete. IHooking!1 of reinforcement is not an acceptable method of positioning. 5. Garage slabs should be poured separately from the residence footings and be quartered with expansion joints or saw cuts. A positive separation from the footings should be maintained with expansion joint material to permit relative movement. 6. Presaturation of slab areas is recommended for these soil conditions. The moisture content of each slab area should be 120 percent, or greater, above optimum and verified by the soil engineer to a depth of 18 inches below adjacent ground grade in the slab areas, within 72 hours of the vapor barrier placement. 7. As an alternative, an engineered post-tension foundation system may be used. Post-tension foundation recommendations can be provided upon request. 8. Soils generated from footing excavations to be used onsite should be compacted to a minimum relative compaction 90 percent of the laboratory standard, whether it is to be placed inside the foundation perimeter or in the yard/right-of-way areas. This material must not alter positive drainage patterns that direct drainage away from the structural areas and toward the street. 9. Foundations near the top of slope should be deepened to conform to the latest· edition of the UBC (ICBO, 1997) and provide a minimum of 7 feet horizontal distance from the slope face. Rigid block wall designs located along the top of slope should be reviewed by a soils engineer. CORROSION Upon completion of grading, additional testing of soils (including import materials) for corrosion to concrete and metals should be performed prior to the construction of utilities and foundations. UTILITIES Utilities should be· enclosed within a closed utilidor (vault) or designed with flexible connections to accommodate differential settlement and expansive soil conditions. Due to the potential for differential se~lement, air conditioning (A/C) units should be supported by slabs that are incorporated into the building foundation or constructed on a rigid slab with Pacific Coast Development Black Rail Ridge, APN 215-070-33 File:e:\wp9\4000\4015a.pge GeoSoils, Ine. w.o. 4015-A-SC September 3, 2003 Page 19 flexible couplings for plumbing and electrical lines. NC waste waterlines should be drained to a suitable outlet. WALLS AND RETAINING WALLS General Foundations may be designed using parameters provided in the "Design" section of . Foundation Recommendations presented herein. Wall sections should adhere to the City of Carlsbad guidelines. All wall designs should be reviewed by a qualified structural engineer for structural capacity, overturning, and stability. The design parameters provided assume that onsite, or equivalent, low expansive soils, . or selected fill, are used to backfill retaining waifs. If expansive soils are used to backfill the proposed walls within this wedge, increased active and at-rest earth pressures will need to be utilized for retaining wall design. Heavy compaction equipment should not be used above a 1:1 projection up and away from the bottom of any wall. The following recommendations are not meant to apply to specialty walls (cribwalls, loffel; earthstone, etc.). Recommendations for specialty walls will be more onerous than those provided herein, and can be provided upon request. Some movement of the constructed waifs should be anticipated as soil strength parameters are mobilized. This movement could cause some cracking dependent upon the materials used to construct the waif. Tq reduce wall cracking due to settlement, walls should be internally grouted and/or reinforced with steel. - Restrained Walls Any retaining walls that will be restrained prior to placing and compacting backfill material, or that have re-entrant or male corners, should be designed for an at-rest equivalent fluid pressures of 65 pcffor native soil backfill, plus any applicable surcharge loading. For areas of male or re-entrant corners, the restrained waif design should extend a minimum distance of twice the height of the wall (2H) laterally from the corner. Building walls below grade should be water-proofed, or damp-proofed, depending on the degree of moisture protection desired. Refer to the following section for preliminary recommendations from surcharge loads. Cantilevered Walls These recommendations are for cantilevered retaining waifs up to 15 feet high. Active earth pressure may be used for retaining wall design, provided the top ofthe wall is not restrained from minor deflections. An empirical equivalent fluid pressure (EFP) approach may be used to compute the horizontal pressure againstthe wali. Appropriate fluid unit weights are provided for specific slope gradients of the-retained material. These do not include other Pacific Coast Development Black Rail Ridge, APN 215-070-33 File:e:\wp9\4000\4015a.pge GeoSoils, Inc. W.O.4015-A-SC September 3, 2003 Page 20 superimposed loading conditions such as traffic, structures, seismic events, or adverse geologic conditions. SURFACE SLOPE EQUIVALENT SELECT OF RETAINED MATERIAL· FLUID WEIGHT PCF MATERIAL PCF (Horizontal to Vertical) (Low Expansive Native Soil) . (Gravel) Level 53 35 2to 1 65 -- The equivalent fluid density should be increased to 65 pcf for level backfill using the native soil at the angle point of the wall (corner or male re-entrant,) and extended a minimum lateral distance of 2H on either side of the corner. However, if the selected backfill with angle of friction of 30 degrees is used, this value may be reduced to 62 pct. Wall Backfill and Drainage All retaining walls should be provided with an adequate gravel and pipe backdrain and . outlet system (a minimum two outlets per wall) to prevent buildup of hydrostatic pressures, and be designed in accordance with minimum standards presented herein. Pipe should consist of schedule 40 perforated PVC pipe. Gravel used in the backdrain systems should be a minimum of 3 cubic feet per lineal foot of 3/8-to 11h-inch clean crushed rock encapsulated in filter fabric (Mirafi 140 or equivalent). Perforations in pipe should face down. The surface of the backfill should be sealed by pavement or the top 18 inches compacted to 90 percent relative compaction with native soil. Proper surface drainage should also be provided. As an alternative to gravel backdrains, panel drains (Miradrain 6000, Tensar, etc.) may be used. Panel drains should be installed per manufacturer's guidelines. Regardless of the backdrain used, walls should be water proofed where they would impact living areas or where staining would be objectionable. Wall Footing Transitions Site walls are anticipated to be founded on footings designed in accordance with the recommendations in this report. Wall footings may transition from formational bedrock to select fill. If this condition is present the civil designer may specify either: a) If transitions from rock fill to select fill transect the wall footing alignment at an angle of less than 45 degrees (plan view), then the designer should perform a minimum 2-foot overexcavation for a distance of 2H and increase overexcavation until such transition is between 45 and 90 degrees to the wall alignment. Pacific Coast Development Black Rail Ridge, APN 215-070-33 File:e:\wp9\4000\4015a.pge GeoSoils, Ine. W.O.4015-A-SC September 3, 2003 Page 21 b) Increase ofthe amount of reinforcing steel and wall detailing (Le., expansion joints or crack control joints) such that an angular distortion of 1/360 for a distance of 2H on either side ofthe transition may be accommodated. Expansion joints should be sealed with a flexible, non-shrink grout. c) Embed the footings entirely into homogenous fill or terrace deposits. Top of Slope/Perimeter Walls The geotechnical parameters previously provided may be utilized for free standing sound walls or perimeter walls, which are founded in either competent bedrock or compacted fill materials. The strength of the 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 placing of jOints (expansion and crack control) should be incorporated into the wall layout. These expansion joints should be placed no greater than 20 feet on-center and should be reviewed by the civil engineer and structural engineer of record. GSI anticipates distortions on the order of 112 to ± 1 inch in 50 feet for these walls located atthe tops offill/cut slopes. To reduce this potential, the footings may be deepened and/orthe use of piers may be considered. Footing Excavation Observation All footing excavations for walls and appurtenant structures should be observed by the geotechnical consultant to evaluate the anticipated near surface conditions prior to the placement of steel or concrete. Based on the conditions encountered during the observations of the footing excavation, supplemental recommendations may be offered, as appropriate. EXTERIOR FLATWORK Exterior driveways, walkways, sidewalks, or patios, using concrete slab on grade construction, should be designed and constructed in accordance with the following criteria: 1 . Concrete slabs should be a minimum 4 inches in thickness. A thickened edge (minimum of 12 inches) should be constructed for all flatwork adjacentto landscape areas. 2. Slab subgrade (Le., existing fill materials) should be compacted to a minimum 90 percent relative compaction and moisture conditioned to the soil's optimum moisture content (120 percent of soil's optimum moisture content for medium expansive soils) to a minimum depth of 12 inches. This should be verified by this office at least 72 hours prior to pouring concrete. The use of Class 2, Class 3, or Pacific Coast Development Black Rail Ridge, APN 215-070-33 File:e:\wp9\4000\4015a.pge GeoSoils,lne. W.O. 4015-A-SC September 3, 2003 Page 22 decomposed granite (Le., OG) as a base for the concrete slab in non-vehicle traffic areas is not required. 3. The use of transverse and longitudinal control joints should be considered to help control slab cracking due to concrete shrinkage or expansion. Two ofthe best ways to control this movement are: 1) add a sufficient amount of reinforcing steel, increasing tensile strength of the slab; and/or, 2) provide an adequate amount of control and/or expansion joints to accommodate anticipated concrete shrinkage and expansion. We would suggest that the maximum control joint spacing be placed on 5-to a-foot centers, or the smallest dimension of the slab, whichever is least. 4. No traffic should be allowed upon the newly poured concrete slabs until they have been properly cured to within 75 percent of design strength. 5. Positive site drainage should be maintained at all times. Water should not be allowed to pond or seep into the ground. If planters or landscaping are adjacent to paved areas, measures should be taken to minimize the potential for water to enter the pavement section. This may be accomplished using thickened pec pavement edges and concrete cut off barriers or deepened curbs, in addition to eliminating granular base materials (Le., Class 2, 3, OG etc.) underlying the slab. 6. In areas directly adjacent to a continuous source of moisture O.e., irrigation, planters, etc.), all joints should be sealed with flexible mastic. 7. Concrete compression strength should be a minimum of 2,500 psi. 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 (Le., 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, Pacific Coast Development Black Rail Ridge, APN 215-070-33 File:e:\wp9\4000\4015a.pge GeoSoils,lne. W.O. 4015-A-SC September 3, 2003 Page 23 long-term movement from this source may be minimized, but not eliminated, by placing the fill throughout the slope region, wet of the 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 Uniform Building Code and/or California Building Code), positive structural separations (Le., joints) between improvements, and stiffening and deepening of foundations. All of these measures are recommended for design of structures and improvements. The ramifications ofthe 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 offill slopes would tend to minimize short-term erosion until vegetation is established. Plants selected for 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. CDraiifage Adequate lot surface drainage is a very important factor in. reducing the likelihood of adverse performance offoundations, 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. Pacific Coast Development Black Rail Ridge, APN 215-070-33 Fife:e:\wp9\4000\4015a.pge GeoSoils, Inc. W.O. 4015-A-SC September 3, 2003 , Page 24 We recommend that unpaved lawn and landscape areas have a minimum gradient of one 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 6t=s-:::'fe~t 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. 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 planters are constructed adjacentto structures, the sides and bottom of the 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 to the type of vegetation chosen and their potential effect upon surface improvements (Le., 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 otherwise 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 Pacific Coast Development Black Rail Ridge, APN 215-070-33 File:e:\wp9\4000\4015a.pge GeoSoils,Ine. W.O.4015-A-SC September 3, 2003 Page 25 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 for the 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. Tile Flooring Tile flooring 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 fqr 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. Pacific Coast Development Black Rail Ridge, APN 215-070-33 File:e:\wp9\4000\4015a.pge GeoSoils, Ine. W.O.401S-A-SC September 3, 2003 Page 26 Footing Trench Excavation All footing excavations should be observed by a representative of this 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 at that time. 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. Utility 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 of the laboratory standard. As an alternative for shallow (12-inch to 18-inch) under-slab trenches, sand having a sand equivalent value of 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 ofthe 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 of the structural engineer. . Pacific Coast Development Black Rail Ridge, APN 215-070-33 File:e:\wp9\4000\4015a.pge GeoSoils, Ine. W.O.4015-A-SC September 3, 2003 Page 27 SUMMARY OF RECOMMENDATIONS REGARDING GEOTECHNICAL OBSERVATION AND TESTING We recommend that observation and/or testing be performed by GSI at each of the following construction stages: • • • , . • • • • • During grading/recertification. After excavation of building footings, retaining wall footings, and free standing walls footings, prior to the placement of reinforcing steel or concrete. Priorto pouring any slabs orflatwork, after presoaking/presaturation of building pads and other flatwork subgrade, before the placement of-concrete, reinforcing steel, capillary break (Le., 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. 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. Pacific Coast Development Black Rail Ridge, APN 215-070-33 File:e:\wp9\4000\4015a.pge GeoSoils, Ine. W.O. 4015-A-SC September 3, 2003 Page 28 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 maybe warranted. LIMITATIONS The materials encountered on the project site and utilized for our analysis are believed representative of the 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 subjectto change with time. GSI assumes no responsibility or liability for work or testing performed by others, ortheir inaction, or work performed when GSI is not requested to be onsite, to evaluate if our recommendations have been properly 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. GeoSoils, Ine. '-' .' ~ , :'-,".' ",,'-:.' ", '.'.~: ,"I t " '. ~" , , '. , ... ' ": .... .'./ . /- :~(:~~ ~,:;. ~".' >-~ :'i;: ' . "/,.', .. ",.:'-J'::':';' :,'",~r r~ .-: , " " ....... ( ~ .. ' .,. -\', -,- ~, :' .- r; ~, -~{.;.-_.~ " .~ ........... J. --.. .. ", ,::').' ;: t, " : ... :~ -' .. " --. \' ,~': '>." - , ' '",,' '''-'. -'",_: ' . " " , -, '<'; ..-- :',-(. , ,~ . ", ", :;., ~( I , ".:', ,. If' i' '. , ... ~"'-,.'.:' , ',1 , " "; ! ~ •• ,1'. .' f : , . ~, , ': .~ , '.' \', ~ - ..: '~ ,0" ' •• '-: .. ",:, ",' :;-' .... ~ :',' -.\ , ~ " .'-~" ,,~ r. '; I" ( , ,. '-' ... ' ~ , ,--; .. ::/,~" " . ,'''' .... , " -..... ~ \'., ;,'" : /~: ,~, ."~~' .... "r.,' " , ,--",., -" ~'. .:-'. -~ . -' ... , --,' , " I I-~." .;;. " -~ ~,(' -,-:' .' .--~ :' ~ '~. ,t "" J -' :.~.' , .-'"' r"'~' : -,':> --'. . :- ,.' f' "" .'-':,' "\--, , "I' " r • '. " ", ~p ; "!' .: . ~ 0 \.'. '. j""" .. , ', ...... , ~. '. ' ,'~ -',' ,', ~ • 1 _ ,~. ~, ,r.,~ ~;} < '.' . "~',: ': : \--"=, , .. ~ < ... 1, •• ;: , " , r . ,'''-.. ,~-i ,.: ,~' ~<~. '::*_r-~., _':;"'~ .~: ~ l ~ '" ~ ' .... ' ;'.~,/.:. --\ '. ~t.~ ':', , .\ ';.:,;: ", :' ~ :', ; ':, .~1::~ J APPENDIX A REFERENCES Blake, Thomas F., 2000a, EQFAULT, A computer program for the 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; Updated to December, 2002, 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. Buccola Engineering, Inc.,2001 (revised 2002) CUP Development Plan, Casa Montessori School, 20 scale, sheet 1 of 1, Job Number 100-121, dated June 25 (revised August 13, 2002). Campbell, K. W. and Bozorgnia, Y. (1997), Attenuation relations for soft rock conditions; in EQFAULT, A computer program for the estimation of peak horizontal acceleration from 3-D fault sources; Windows 95/98 version, Blake, 2000a. Campbell, K.W., 1997, Empirical near-source attenuation relationships for horizontal and vertical components of peak ground acceleration, peak ground velocity, and pseudo-absolute acceleration response spectra, Seismological Research Letters, vol. 68, No.1, pp. 154-179. Hart, E.W. and Bryant, W.A., 1997, Fault-rupture hazard zones in California, Alquist-Priolo earthquake fault zoning act with index to earthquake fault zones maps; California Division of Mines and Geology Special Publication 42, with Supplements 1 and 2, 1999. 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, in eds., Johnson, J.A., Campbell, K.W., and Blake, T.F.: AEG Short Course, Seismic Hazard Analysis, June 18, 1994. GeoSoils,lne. __ , 1982b, Prediction of earthquake response spectra, U.S. Geological Survey Open-File Report 82-977, 16p. 'Kennedy, M.P. and Tan S.S., 1996, Geologic maps of the northwest part of San Diego County, California., Division of Mines and Geology, Plate 2, scale 1 :24,000. Sadigh, K., Egan, J., and Youngs, R., 1987, Predictive ground motion equations, in Joyner, W.B. and Boore, D.M., 1988, measurement, characterization, and prediction of strong ground motion, in Von Thun, J.L., ed., Earthquake engineering and soil dynamics", recent advances in ground motion evaluation, American Society of Civil Engineers Geotechnical Special Publication No. 20, pp. 43-102. Sowers and Sowers, 1970, Unified soil classification system (After U. S. Waterways Experiment Station and ASTM 02487 -667) in Introductory Soil Mechanics, New York. Pacific Coast Development File:e:\wp9\4000\4015a.pge GeoSoils, Ine. Appendix A Page 2 " •• ;.# .... , •.• ... " ..... ,'. ... I~ :- ~. ~ ,~ . ¥':. ,~ l~'_\'~~~~ ;,~,:\./ .to ., ';".,-"' f"· .... ' •• \:! " . ! I"; . "', ~ . ~ -. -. --!. • , " ~ " ' .:' : ,~ .. ' :. ',~-:". -.... ~. ~ ..,\ '! " ~ , . ::;"." 7 ,>/ .::~ . I ..... ,' ,-'. " ::: .~-";" 1"-: .: " ..... ': • " I~_ <".~t. ' '.~,"!' :.' .... ! ;' 'J.' ,"-.. , ' .... " '.' ~:"'-,', . , ~ , .', ~ . : , .. - '.r , I. \ ",: ..... '. ,', , ",," '. .~ ,- ',', .. -, , , ~ ',~ ,.:..",- . ',: '-~ " \, .:' -. " , --, " ,', .. ,' s.· " ."<.' , , '- . " _I. ~ .••. _( ," ~ {'" ." . --,", -, ,~.,' ',' . ~ " , ~. , '. .,~- , ~ "l~_.: \'_ • ,', '. ' • ;:.~: r . I, ; , } ": '" . ~. , "",' } " " " :~ :-,.' ':./ ~ ~ ',t" : " < <. I , ' . '":~ \", " " '.!" , .; .-"" ~. '. ~ .), 1.:·' : ... , . , " ~ .... " " .,; , ", , -', -,>~, ,,' .' ~ ':,~ ,-, " -, -, :--,:,~' : ~ 1 ... , 'I: . . ,~ . '~~!.r L'~ '.: .... -;; • , -.. ~, ,.', ... ~., ,. -:-:..c !.:~~~'> I. :" ~_":, ~ -~;:/-~ ~ . ?::, ~': ... , .:. , , ~ • I~. ' ":,,-': .. , ' I; , :> ~ ,,'1:. ,,~,;:. r < ~ .. ' ~, j'{,., ;:: " .. to. -""'': ."';" ; ... ,~. -\" ... -:::. ,-" . . ' -'. ... ,' ,' . f~:. :,! .... ~ ',',,-).' '-~~ .. '::""'" ,.; -'-;-> , ~.,,: '. :"~ ~~" -:,.-' ~~";;' i," '~:, ,~ .... ~:-.>., "'r'; .~ .¥ :,{ , -:... ',.. , , ., ",:-. , " \>-:. . ~, ,-, , , ',' ,'" I :,', '~," . t :. ,'.-," ,'~ , *,., " > ' ", : ---,,; ,:' \', ..... :.. ;""" .. _,I ,,' \;., . ,.: l~" ',' . , " •• ~\~' ,: \ '.' ' e' 'f~" r' •. , ~:'~, " . ~. '>I-,." """, .~. ,','~ ", .~' • • \ ~ I' .. ;. ~.~ -" '" . ,,*~ .. , . -~) ~ ,; ~ .~ ". , ' ... , .' -:~.,,' ... ~. ~ '. .-'!:", .'~~, .... --): ~:,. ''':.', ,""'-<1' ',: ~~H· W.O.4015-A-SC Pacific Coast Development August 21, 2003 LOG OF EXPLORATORY TJ:ST PITS ----.. _------------_ .. _-----------------_. --------_._--------- TEST .. ' ·SAMPLE:_ .. ·· FIELD DRY.:' .. ~. " .. :: '.: :" .. ,,'/ .. : .. :' . : : .. ' .' , .. PIT NO. DEPTH GROUP DEPTH' . . MOISTURE DENSITY' DESCRIPTION (ft.) SYMBOL (ft.) (%) (pef) '. TP-1 0-1Y2 SM ARTIFICIAL FILL (UNDOCUMENTED): SILTY SAND, yellow brown, damp, loose; porous, deleterious debris. 1%-3 SM Undisturbed @2 7.2 . 128.6 COLLUVIUM: SILTY SAND, dark red brown, moist, medium dense; porous. 3-5 CL Undisturbed @ 3 104.0 21.1 TERRACE DEPOSITS: SANDY CLA V, light brown, wet, Bulk @ 3-5 stiff. , 5-5112 SC CLA VEV SAND, orange, moist, dense. Total Depth = 51121 No Groundwater/Caving Encountered Backfilled 8-21-2003 PLATE B-1 . . TEST SAMPLE. PIT NO. DEPTH GROUP DEPTH (ft.) SYMBOL {ft.} . TP-2 0-1% SM 1%-3 SP 3-3% CL W.O.4015-A-SC Pacific Coast Development . August 21, 2003 LOG OF EXPLORATORY TEST PITS -_ .. _--_ .. . . ,', .. .. FIELD DRY' ." " MOISTURE DENSITY DESCRIPTION· . (%) (pef) ARTIFICIAL FILL (UNDOCUMENTED): SIL TV SAND, yellow brown, damp to moist, loose; porous. COLLUVIUM: SAND w/SILT, red brown, moist, medium dense; porous. TERRACE DEPOSITS: SANDY CLAY, brown, moist, stiff. Total Depth =·3%' I No Groundwater/Caving Encountered Backfilled 8-21-2003 PLATE 8-2 . I I ~ H· ------------ TEST PIT NO. DEPTH GROUP (ft.) SYMBOL TP-3 0-1 SM 1-1% SM 1%-2 CL 2-3 SL I , W.O.4015-A-SC Pacific Coast Development August 21, 2003 LOG OF EXPLORATORY TEST PITS -----------------------.~--~.--.-.---------~ .. ' , 'SAMPLE FIELD DRY .. , . , DEPTH, MOISTURE DENSITY DESCRIPTION (ft.) (%) (pel) ARTIFICIAL FILL (UNDOCUMENTED): SILTY SAND, yellow brown, damp to moist, loose; porous, deleterious debris. COLLUVIUM: SILTY SAND, dark red brown, moist, loose; porous. TERRACE DEPOSITS: SANDY CLAY, brown, moist, stiff. CLAYEY SAND, orange to light gray, moist" dense. i I , I Total Depth = 31 No Groundwater/Caving Encountered Backfilled 8-21-2003 PLATE 8-3 ~~H· TEST PIT NO. DEPTH GROUP (ft.) SYMBOL TP-4 0-1% SM 1%-2% SM W.O.4015-A-SC Pacific Coast Development August 21. 2003 LOG OF EXPLORATORY TEST PITS ---..... • !.' ", 'SAMPLE' : FIELD DRY .. , ' DEPTH MOISTURE' DENSITY DESCRIPTION' (ft.) (%) (pet) , ARTIFICIAL FILL (UNDOCUMENTED): SILTY SAND. yellow brown to dark red brown, damp, loose; porous. TERRACE DEPOSITS: SILTY SAND, yellow brown, dry, very dense. Practical Refusal @ 2%' No Groundwater/Caving Encountered Backfilled 8-21-2003 PLATE 8-4 ~. i i i . . TEST SAMPLE· . PIT NO. DEPTH GROUP .. DEPTH' : (ft.) SYMBOL (ft.) TP-5 0-% SM %-1% SM 1%-2 SM W.O.4015-A-SC Pacific Coast Development August 21. 2003 LOG OF EXPLORATORY TEST PITS i i i .. . . FIELD DRY ". " . MOISTURE . DENSITY DESCRIPTION (%) . (pef) : ARTIFICIAL FILL (UNDOCUMENTED): SILTY SAND, yellow brown, moist, loose; porous. . COLLUVIUM: SILTY SAND, dark red brown, saturated, loose; porous, perched groundwater encountered. TERRACE DEPOSITS: SILTY SAND, orange to yellow brown, damp, very dense. Practical Refusal @ 2' Perched Water @ 1%' Slight Caving . Backfilled 8-21-2003 PLATE 8-5 ~H· TEST SAMPLE PIT NO. DEPTH GROUP DEPTH' (ft.) SYMBOL (ft.) TP-6 0-1 SM 1-1% SP W.O.4015-A-SC Pacific Coast Development August 21, 2003 LOG OF EXPLORATORY TEST PITS ", FIELD DRY' MOISTURE DENSITY ' DESCRIPTION (%) (pef) ARTIFICIAL FILL (UNDOCUMENTED): SILTY SAND, light brown, dry, medium dense; porous. TERRACE DEPOSITS: SAND w/SILT, yellow brown, , dry, very dense. Practical Refusal @ 1 %' No Groundwater/Caving Encountered Backfilled 8-21-2003 PLATE 8-6 ...-',' .: .~ " " /:7,,°, ~. : ...... ~. ~.' ~ • • t ;,"': ~ ',(. . :~, ~;..:.{, -,' . \ ~ ~ , ~ , . '. ~ ~ ,>~" • \,4,: • .. ~', : , , ( ~' ~ ',.' '~ .. ,~ : .... ':,'~' ',-:~,. ~"""': .,' ,"-', , , : ...... ,:. '" \/:' ,;,':, ; ..... . '1: ,:" ,', <.. :-',~ ~~ -:. ,,\ ' •. I :'~ ': .,' .,' '": : ~'It.. .... , "': 0 .~~ I ':,:-:: . ~.,. , ". " ',1: .;. '01,' , " , t':'~: ' . 'I ' ,-.",' ,~ . ,,:. ,., . <';. :. , "'-', ;', ' " J, J, ~ 0". . ,. '., " • t~, ." :" -: 0' ',.:' :. , ~. ", , ' "'f"':'· 'w ,." ... ," .. ~ ' .. ' . ~ \, ",' .~ . ',.\ "I -', . ' ~' , -.' • ,"1, . '_,J ,.j .... '.; ':". ",I' , " " , " -' " '" A",' :. ' .. " . ~' ," , ,',' .. ~ , , ,,' ;: '. , .. , ,\ ~ I • ~~.~. ,'" , 0.' ", I,":. 1.-; .... , . • ~ w , , . ;:. ".<' " " < .- " ~. ' , , ,". ,'1'. ), .~. .!.. ( ':, .' MAXIMUM EARTHQUAKES·· PACIFIC COAST DEVELOPMENT 1 x x x ...-... x 0) ........... x c .1 ~?X 0 .~ .-. x ......, co 1 ~ Q) -Q) u u « .01 .001 .1 1 10 100 Distance· (mi) .. W.O. 4015-A-SC PlateC-1 EARTHQUAKE EPICENTER MAP PACIFIC COAST DEVELOPMENT 1100,-----------------------------------------------------~ 1000 900 aoo 700 600 500 400 300 200 LEGEND x M=4 100 o M=5 D M=6 6. M=7 0 OM=a -100~~~~~~~~~~~4J~~~~~~~~~~~~~~~~ -400 -300 -200 -100 o 100 200 300 400 500 600 W.O.4015-A-SC Plate C-2 'I 100 10 EARTHQUAKE RECURRENCE CURVE PACIFIC COAST DEVELOPMENT ~ ....... ........ -.......... ' , ..... ~ ......... ~ 4 , , , ....... ..... 0 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I "" 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 (M) W.O.4015-A-SC Plate C-3 P'ROBABILITY OF EXCEEDANCE CAMP. & BOZ. (1997 Rev.) SR 1 I. I I. ,. 25 yrs 50 yrs I. I I T I 75 yrs 100 vrs 100~--~--~--~--~--~----~ .. 90~--~--~--~--~--~--~~ ~.Il 111 I 1111 1111 r 0.00 0.25 0.50 0.75 1.00 1.25 1.50 Acceleration (g) W.O. 4015-A-SC Plate C-4 ~ ~ .p. o 'RETU'RN PERIOD vs. ACCELERATION, CAMP. & BOZ. (1997 Rev.) SR 1 ~ 10000000 I (I) (") ,.......... en L.. ~ ""'-"" "'C 0 .-L.. Q) c.. c: L.. ' ::J ....., Q) 0::: "'D iii' .... CD (") I CJ1 1000000 100000 10000 1000 100 0 .. 00 0.25, 0.50 0.75 1.00 1.25 '1.5,0 Acceleration, (g) ::-:,""_.""lj, , ... _. ,I :" '-'-'-, ' , "'" . i~ ~. - .' !-. :-: .. ~ ." ~' .' -:'~',.\ ," .. ' .. -~ . ,,~ ;.'~ ',.t , '.~ , - '1 -, ,.1 -'- '" ~, ;~. :~ ,,'. ..:. , , " . " t, _ .:: ~ f-,.,,':" ~4.' ::.: >:" : _~.:, : ,~' .,,:1:, .:~, ~'::' '_.~;~"" ~F •• :~. _ ,~, ":' .' .. -" ~ '. I ,,} : • .:' ..! : .. .., -:. .... .. ,;, )-'. " -".-'" "',' ~ , ~ :. ~ . ,., ~. ":. ',', .: :~ .' "~':;": .~.-r'., .. -., ; "':j; ,; ~ , . ~.;' '-''''(_~·'l. < ~~ ;, >"~ t ---~ "!", :." ~ \ .~\ ~ ':·~"7·~" .......... ' ... >-, ~ . " • ";,, ~> r ~- ,1 \, -) ,'::!' >','. I ',', '~~ .. ".' -" -;" .~". '," ... ' .'. ",'" , ,'"'-" , ,. ~' ... ' . '- , -.' ~ ,,' ., '~j-". ,}. ';"'-'. ",- '~ - '. '. "., '. -.1 '" 'j "-', " " ' ;, -' ::l ... ~ ~~~' .. ' :-. ' .. . " ~ .- " -<; -\. ;, ~ "~:' ~i'" ~, , ;, ; ,-". r ! ...... "'!: .... -" ~'. ~ .. : ; ~, .:~ ',: -, . ,,-.,t-' , . . -, , ' '-I " . -.' . "'-"~ . : -, -_ ..... ~. ,-t I '" ',Yo I " , • >.", " -~ ,:' ... '. " ? '. 'i :, " ,.::,.;. .. ' " , " : •.... ; ~,,: ,- ~ ,- '~,-,: :,' r,.",-_, .. \, " , I;' ",.: '-'j ... , .. '.-, , • 1 •• , , OJ,,: 1 __ .~ ,,-' " -"., , , '. . ~,--: ' '. ',' :.~. '0 ' " '~ \' f , ~ ." .:.. I', _, " ":-... ' ,I, I-" ,- -'-' ~ ", ,~ ~ ,i ~ ~.: .. .. ,.t." -:"',,---' '~. ~-~,.~~.~" .t.'.._ " ";, , . " ",' .~ ' . .- '-~.,,' , : .... :, ... : ,,3. ~V _ ", .. ': 3,000 2.500 2.000 ' ' .... III Co :r: d~ t5 z w 1.500 g: ~ rn V IX: iii J: rn ~ 1.000 V / / 500 / / a • 0 500 1.000 1.500 2.000 2.500-3,000 NORMAL PRESSURE. psf Sample Depth/EI. Primary/Residual Shear Sample Type 'Y.s MC% C + • TP-3 0.0 Primary Shear Remolded 114.3 10.5 141 ,27 ~ • TP-3 0.0 Residual Shear Remolded 114.3 10.5 -126' 27 ~ iii 5 t!) 5 " g? ~ Note: Sample Innundated prior to testing ~ II) ij GeoSoils, Inc. DIRECT SHEAR TEST ~ ffi 6 Q -5741 Palmer Way Project: -PACIFIC COAST DEVELOPMENT . JBc. Carlsbad, CA 92008 frl ~... Telephone: (760) 438-3155 Number: 4015-A-SC a:: i5 Fax: (760) 931-0915 Date: September 200~ PI~te: 0-1 gs 60 V / V- Cl CH / / 50 V/ V / / / ~ 40 / C i/ V ~ / / ~ ~ 30 / en / / :s / a. / / 20 / ;/ / - 10 V •• /' / V CL-Ml ./ Ml MH 0 I 0 20 40 60 80 ',100 LIQUID LIMIT Sample Depth/EI. LL PL PI Fines Classification • TP-3 0.0 30 18 12 '" ( ~ ~ 15 C! ~ ; ~ ~ C> .. ~ ATTERBERG LIMITS' RESULTS ~ GeoSoils, Inc. :::; li1 ft 5741 Palmer Way Project: PACIFIC COAST DEVELOPMENT w Carlsbad, CA 92008 III 0:: Telephone: (760) 438-3155 Number: 4015-A-SC ~ Fax: (760) 931-0915 Date: September 2003. . , Plate: '0 -2 - II) ::l M. J. Schiff & Associates, Inc. Consulting Corrosion Engineers -Since 1959 431 W. Baseline Road Claremont, CA 91711 Phone: (909) 626-0967 Fax: (909) 626-3316 E-maillab@mjschiff.com website: mjschiff.com Table 1 -Laboratory Tests on Soil Samples PCD Your #4015-A-SC, MJS&A #03-1000LAB 27-Aug-03 Sample ID Resistivity as-received saturated pH Electrical Conductivity Chemical Analyses Cations calcium ci+ magnesium Ml+ sodium Nal+ Anions carbonate C03 2- Units ohm-cm" ohm-cm mS/cm mg/kg mg/kg mg/kg mg/kg bicarbonate HC03 1-mg/kg chloride CI1-mg/kg sulfate sot mg/kg Other Tests ammonium NH4 1+ mg/kg nitrate "NOt mg/kg sulfide S2-qual Redox mv TP-3 @0-3 2,900 1,000 4.9 0.33 168 44 19 ND " 85 45 488 na na na na Electrical conductivity in millisiemens/cm and chemical analysis were made on a 1:5 soil-to-water extract. mg/kg = milligrams per kilogram (parts per million) of dry soil. " Redox = oxidation-reduction potential in millivolts" NO = not detected na = not analyzed W.O. 4015-A-SC Plate 0-3 Page 1 ofl i~ , ~ , ~: ' >r" '<' ,:' "; ,:: :':,:":~(' -:>' ~-" . " '.' .... • ' ••• < .,-':.: .' , .' \ '\ , ... .. ~ I ' ( '," . ',;1' (-.-,', ~ . "I' • ~ ", , , '-~ ,- ; ..... .. rl "1.', -.'. '.,.,..'" , " . ~ . -, /.:-; " . '1; .-,;.., ~. 1 " • , 't' ",- ,.' ~'.' , J':( , . :;' ~ ~,' ~, '" ",'.-, . ; ~ ";"'" " .t -;:,t ,-J ' , ~~. -Y,. "', .. ~ ," .. '-'" , .... , -" ~., "', . .:,' '.1':, '. '. ' • 'l-")-" .. ~~ \. "~ :,), r~ -'~'" ,'-. '. :. " ~, . , > -~ • " '~, ','-~ t, .,' .~ " '. ~ I r ',-,1 ~:. .,.,:: ,'." ... ' , , ,~ \ ,'- , ' ",'. .',' '" -', ", " .. . ' ,',J .,-. , ',' '. .,~ I., , .... ." ',' -l 1'~. , , ,:~ 'J t: . " " '!' ." ••• ' ,. > .... ~ ',,~-, . ,-~ '\ : -. ..... . -: ~,..:: ~ - • ,w,'_ '" ",-,',"'; " "":',; -,-)- , "': ', .. ' <':: ~ : .... ,.,' .. ::-.'~", .,' ,', " ',:~ " ,,':- .~ , 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 hereaft.er 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 contractor is 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 Prior to 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 by the project engineering geologist and/or soil engineer prior to placing and fill. It isthe contractors's responsibility to notify the engineering geologist and soil engineer when such areas are ready for observation. Laboratory and Field 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 0-1557-78. Random field compaction tests should be performed in accordance with test method ASTM designation 0-1556-82, 0-2937 or 0-2922 and 0-3017, at intervals of approximately 2 feet of fill height or every 100 cubic yards of fill placed. These criteria would vary depending on the soil conditions and the size of the project. The location and frequency of testing would be at the discretion of the geotechnical cons41~ant. GeoSoils, lne. ...---------------------------------------:------ 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 of the soil engineer. The contractor should also remove all major non-earth material considered unsatisfactory by the soil engineer. It is the sole responsibility of the 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 compaction equipment should be provided by the contractor with due consideration forthe fill material, rate of placement, and climatic conditions. If, in the opinion of the geotechnical consultant, unsatisfactory conditions such as questionable weather, excessive oversized rock, or deleterious material, insufficient support eqUipment, etc., are resulting 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 conditions are satisfactory . During construction, the contractor shall properly grade all surfaces t6 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 until such time as permanent drainage and erosion control measures have been installed. SITE PREPARATION All major vegetation, 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. Existing fill, soil, alluvium, colluvium, or rock matl3rials determined by the soil engineer or engineering geologist as being unsuitable in-place should be removed prior to fill placement. Depending upon the soil conditions, 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, septic 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 condition should be overexcavated down to firm ground and approved by the soil engineer before compaction. and filling operatfons continue. Overexcavated and processed soils which have been properly mixed and moisture conditioned should be re-compacted to the minimum relative compaction as specified in these guidelines. Pacific Coast Development File:e:\wp9\4000\4015a.pge GeoSoils, lne. AppendixE Page 2 Existing 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 optimum 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. Scarification, disc harrowing, or other acceptable form of mixing should continue until 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 soil 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 by the 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 1h 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 of the 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 fitJ benches should be observed and approved by the soil engineer and/or engineering geologist prior to placement of fill. Fills may then be properly placed and compacted until design grades (elevations) are attained. COMPACTED FILLS Any earth materials imported or excavated on the property may be utilized 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 deleterious materials. All unsuitable materials should be removed from the fill as directed by the soil engineer. Soils of poor gradation, undesirable expansion potential, or substandardstrength characteristics may be designated by the consultant as unsuitable and may require blending with other soils to serve as a satisfactory fill material. ' Pacific Coast Development File:e:\wp9\4000\4015a.pge GeoSoils, lne. AppendixE Page 3 Fill materials derived from benching operations should be dispersed throughout the fill area and blended with other bedrock derived material. Benching operations 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 location of materials and disposal methods are specifically approved by the soil engineer. Oversized material should be taken off-site or placed in accordance with recommendations of the soil engineer in areas designated as suitable for rock disposal. Oversized material should not be placed within 10 feet vertically of finish grade (elevation) or within 20 feet horizontally of slope faces. To facilitate future trenching, rock should not be placed within the range of foundation excavations, future utilities, or underground construction unless specifically approved by the soil engineer and/or the developers representative. If import material is required for grading, representative samples of the materials to be utilized 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 of this 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 approvethick lifts iftesting 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 less than optimum should be watered and mixed, and wet fill layers should be aerated by scarification or should be blended with drier material. Moisture condition, blending, and mixing of the fill layer should continue until 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 designation, 0-1557-78, or as otherwise recommended by the soil engineer. Compaction equipment should be adequately sized and should be specifically designed for soil compaction or of proven reliability to efficiently achieve the specified degree of compaction. . Where tests indicate that the density of any layer of fill, or portion thereof, is below the required relative compaction, or improper moisture is ·in evidence, the particular layer or . portion shall be re-worked until the required density and/or moisture content has been attained. No additional fill shall be placed in an area until the last placed lift offill has been Pacific Coast Development File:e:\wp9\4000\4015a.pge GeoSoils, Ine. Appendix E Page 4 -. I tested and found to meet the density and moisture requirements, and is approved by the soil engineer. Compaction of slopes should be, accomplished by over-building a minimum of 3 feet horizontally, and subsequently trimming back to the design slope configuration. Testing shall be performed as the fill is elevated to evaluate compaction 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. A final determination offill slope compaction should be based on observation and/or testing of the finished slope face. Where compacted fill slopes are designed steeper than 2: 1 (horizontal to vertical), specific material types, a higher minimum relative compaction, and special grading procedures, may be recommended. Ifan alternative to over-building and cutting back the compacted fill slopes is selected, then special effort should be made to achieve the required compaction in the outer 10 feet of each lift of fill by undertaking the following: 1. ' An extra piece of equipment consisting of a heavy short shan ked sheepsfoot should be used to roll (horizontal) parallel to the slopes continuously 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-rolling. 3. Field compaction tests will be made in the outer (horizontal) 2 to 8 feet ofthe slope at appropriate vertical intervals, subsequent to compaction operations. 4. After completion of the slope, the slope face should be shaped with a small tractor, and then re-rolled with a sheepsfoot to achieve compaction to near the slope face. Subsequent to testing to verify compaction, the slopes should' be grid-rolled to achieve compaction to the slope face. Final testing should be used to confirm compaction after grid rolling. 5. Where testing indicates less than adequate compaction, the contractor will be responsible to rip, water, mix and re-compact the slope material as necessary to achieve compaction. Additional testing should be performed to verify compaction. 6. Erosion control and drainage devices should be designed by the project civil engineer in compliance with ordinances of the controlling governmental agencies, and/or in accordance with the recommendation' of the soil engineer or engineering geologist. Pacific Coast Development File:e:\wp9\4000\4015a.pge GeoSoils, Ine. , Appendix E Page 5 SUBDRAIN INSTALLATION Subdrains should be installed in approved ground in accordance with the approximate alignment and details indicated by the geotechnical consultant. Subdrain locations 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 conditions .. The location of constructed subdrains should be recorded by the project civil engineer .. EXCAVATIONS Excavations and cut slopes should be examined during grading by the engineering geologist. If directed by the engineering geologist, further excavations or overexcavation 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 of the fill portion of the slope. The engineering geologist should observe all cl!t 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 anticipated or not. Unless otherwise 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. Additionally, short-term stability of temporary cut slopes is the contractors responsibility. Erosion control and drainage devices should be designed by the project civil engineer and should be constructed in compliance with the ordinances of the controlling governmental agencies, and/or in accordance with the recommendations of the soil engineer or engineering geologist. COMPLETION Observation, testing and consultation by the geotechnical consultant should be conducted during the grading operations in order to state an opinion that all cut and filled areas are graded in accordance with the approved project specifications. After completion of grading and after the soil engineer and engineering geologist have finished their observations of the work, final reports should be submitted subject to review Pacific Coast Development File:e:\wp9\4000\4015a.pge GeoSoils,lae. Appendix E Page 6 by the controlling governmental agencies. No further excavation or filling should, be undertaken without prior notification 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 practical after completion 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 considerations for use by all employees on multi-employer construction sites. On ground personnel are at highest risk of injury and possible fatality on grading and construction projects. GSI recognizes that construction activities 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 times. 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 testing and observation, the following precautions are to be implemented for the safety offield personnel on grading and construction projects: Safety Meetings: GSI field personnel are directed to attend contractors regularly scheduled and documented safety meetings. Safety Vests: Safety vests are provided for and are to be worn by GSI personnel at all times 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. ' Flashing Lights: All vehicles stationary in the grading area shall use rotating or flashing amber beacon, or strobe lights, on the vehicle during all field testing. While operating a vehicle in the grading area, the emergency flasher , on the vehicle shall be activated. In the event that the contractor's representative observes any of our personnel not following the above, we request that it be brought to the attention of our office. Pacific Coast Development File:e:\wp9\4000\4015a.pge GeoSoils, IRe. AppendixE Page 7 Test Pits Location, Orientation and Clearance The technician is responsible for selecting test pit locations. A primary concern should be the technicians's safety. Efforts will be made to coordinate locations with the grading contractors authorized representative, and to select locations following or behind the established traffic pattern, preferably outside of current traffic. The contractors authorized representative (dump man, operator, supervisor, grade checker, etc.) should direct excavation ofthe 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 condition. Alternatively, the contractor may wish to park a piece of equipment in front of the test holes, particularly 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 enterthis zone during the testing procedure. The zone should extend approximately 50 feet outward from the center of the test pit. This zone is established for safety and to avoid excessive ground vibration which typically decreased test results. When taking slope tests the technician should park the vehicle directly above or below the test location. If this is not possible, a prominent flag should be placed at the top of the slope. The contractor's representative should effectively keep all equipment at a safe operation distance (e.g., 50 feet) away from the slope during this testing. ' The technician is directed to withdraw from the active portion ofthe fill as soon as possible following testing. The technician's vehicle should be parked at the perimeter ofthe fill in a highly visible location, well away from the equipment traffic pattern. The contractor should inform our personnel of all changes to hau I 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 of the 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 solution. However, in the interim, no further testing will be performed until the situation is rectified. Any fill place can be considered unacceptable and subject to reprocessing, recompaction or removal. In the event that the soil technician does not comply with the above or other established safety guidelines, we request that the contractor brings this to his/her attention and notify this office. Effective communication and coordination between the contractors representative and the soils technician is strongly encouraged in order to implement the above safety plan. Pacific Coast Development File:e:\wp9\4000\4015a.pge GeoSoils, Ine. Appendix E Page 8 Trench and Vertical Excavation It is the contractor's responsibility to provide safe access into trenches where compaction testing is needed. Our personnel are directed not to enter any excavation 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 conditions 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. Ifthe contractor fails to provide safe access to trenches for compaction testing, our company policy requires that the soil technician withdraw and notify his/her supervisor. The contractors representative will eventually be contacted in an effort to effect a solution. All backfill not tested due to safety concerns or other reasons could be subjectto reprocessing and/or removal. If GSI personnel become aware of anyone working beneath an unsafe trench wall or vertical excavation, we have a legal obligation to put the contractor and owner/developer on notice to immediately correctthe situation. If corrective steps are nottaken, GSI then has an obligation to notify CAL-OSHA and/or the proper authorities. Pacific Coast Development File:e:\wp9\4000\4015a.pge GeoSoils, Ine. '. AppendixE Page 9 CANYON SUBDRAIN DETAIL TYPE A PROPOSED COMPACTED FILL· SEE ALTERNATIVES TYPE B _...-_--.------_ .... ---------------------. , PROPOSED COMPACTED FILL , , , . . . _, " _ .,--NATURAL GROUND -~ ~ . l/f\\ " -lit NOTE: ALTERNATIVES. LOCATION AND EXTENT OF SUBORAINS SHOULD BE DETERMINED BY THE SOILS ENGINEER ANDIOR ENGINEERING GEOLOGIST·DURING GRADING. PLATE. EG __ 1· CANYON SUBDRAIN ALTERNATE D,ETAILS ALTERNATE 1: PERFORATED PIPE AND FILTER MATERIAL A-1 . FILTER MATERIAL: MINIMUM VOLUME OF 9 FT.:I ~~~, .~ .... :oY'. ~. :;..,.. ,~ ILINEAR FT •. 6-_ ABS OR PVC ,PIPE OR APPROVtO' .:: ••• ~:: ' SUBSTITUTE WITH MINIMUM 8 (1/1.· II PERFS. :: •••• '" LINEAR FT. IN BOTTOM HALF OF' PIPE. • ••• ~ ••• : \\ ASTM 02751. SDR 3S OR ASTM 01-527, SCHD .. 1.0 ASTM 03031.i SOR 3S OR ASTM 017851. SCHOo 1.0 FOR CONTINUOUS RUN IN EXCESS OF SuO FT. USE s-t PIPE . FILTER MATERIAL. . SIEVE SIZE PERCENT PASSING 1 INCH ,10b '3/1. INCH 90-::100 3/8 INCH 1.0-100 NO.1. 25-'0. NO.8 18-33 .NO. 30 ~S-1S' -NO. 50 .0-7' NO. 200 0-3 ALTERNATE 2: PERFORATED PIPE. GRAVEL AND.FILTER FABRIC ~NI~UM OVERLAP 6-MINIMUM OVER~~( :~::.:.:,. ..: ... j-MINIMUM ,COVER .;0 =4'· MINIMUM BEDDING A-2 . GRAVEL 'MATERIAL 9 F'r/LINEAR FT_ PERFORA TEO PIPE: SEE ALTERNATE 1 GRAVEL.: CLEAN 3/4 INOi ROCK OR APPROVED SUBSiiTUTE FILTER FABRIC: MIRAFI 140 OR APPROVED SUBSTiTUTE ',PLATE EG-2 ''\.: DETAIL FOR FILL SLOPE TOEING OUT ON FLAT ALLUVIA TED CANYON TOE OF SLOPE AS SHOWN ON GRADING PLAN ORIGINAL GROUND SURFACE TO BE RESTORED WITH COMPACTED FILL _ :2':~GI':L~R~D SUR~AC~ 8ACKCU~ VARIES. FOR DEEP REMOVALS, /...f r . " , BACKCUT :t~SHOULD BE MADE NO <.$'~ "" " STEEPER'THA~:1 OR AS NECESSAR~~~ ANTICIPATED ALLUVIAL REMOVAL FOR SAFETY """----~,CONSIDERATIONS7 1" ' ~ DEPTH PER SOIL ENCiNEER. ~J~ ,,/ . ~1~'\..,,/\ ~\~V}~~PROViOEA 1:1 NaNIMUMPROJECTioNFROM TOE' OF SLOPE AS SHOWN ON GRADING PLAN TO THE RECOMMENDED REMOVAL DEPTH. SLOPE HEIGHT, SITE CONDITIONS AMDIOR LOCAL CONDITIONS COULD DICTATE FLATTER PROJECTIONS. REMOVAL ADJACENT TO EXISTIN,G FILL ADJOINING CANYON ALL -----~ -------------. PROPOSED ADDITiONAL COMPACTED F.JLL COMPACTED FILL LIMITS LINt;'. . ~ TEMPORARY COMPACTED FILL ~ --- . ;"FOR DRAINAGE ONLY ___ ---.", ~ Qaf U'<o' Qaf / Qal {TO BE REMOVED) , (EXISTING,COMPACTED FlLU "'~,~ i.,., . ~'I.~~II~ k~fWpr!~ \ LEGEND ~y~\ ~ \\ TO BE REMOVED BEFORE Oaf ARTIFICIAL 'FILL PLACING ADDITIONAL' COMPACTED FILL Oal ALLUVIUM PLATE EG-~ -u r » .., m· m G> I .J:' TYPI'CAL STABILIZATION I BUT"TRESS" FILL DETAIL 15' TYPICAL 1,....2· "' ...... ".~ 'J ,,'C i >' >>...i e. OUTLETS TO BE SPACED AT 100' MAXIMUM INTERVALS. AND SHALL EXTEND 1r BEYOND THE FACE OF SLOPE AT TIME OF. ROUGH GRADING COMPLETION. BLANKET FILL IF RECOMMENDED BY THE SOIL ENGINEER ·\\Vi,A\lm------ l..d iii wl\.\ . • -.• _-~ ,-DIAMETER NON-PERFORATED OUTLET PIPE ..-..J AND BACKDRAIN (SEE ALTERNA nVES) • ~r\ . 3' MINIMUM KEY DEPTH \. TYPICAL ST ABIL,ZA TION I BUTTRESS SUBORAIN O,ET AIL 4· MINIMUM r MINIMUM PIPE I.. MINIMUM ,,' "'1J r » -I m rn G) I tn :E ::I ~ ?: :2: • N i-MINIMUM FILTEOR MATERIAL: MINIMUM OF FIVE FP/LINEAR Fl OF PIPF OR FOUR FP/LINEAR FI OF PIPE WHEN PLACED IN SQUARE CUT TRENCH. ALItRNATIVE IN LIEU OF FILTER MATERIAL: GRAVEL MAY B ENCA~ED IN APPROVED FILTER FABRIC. FILTER FABRIC SHALL BE MIRAFI140 OR EQUIVALENT. FILTER FABRIC SHALL BE LAPPED A MINIMUM OF 128 ON ALL JOINTS. MINIMUM 4-DIAMETER PIPE: ABS-ASTM 0-2751, SDR 35 OR ASTM 0-1521 SCHEDULE 40 PVC-ASTM 0-3034, SPR 035 OR ASTM 0-1785 SCHEDULE 40 WI.TH A CRUSHING STRE~OTH OF 1,000 POUNDS MINIMUM. AND A MINIMUM OF B UNIFORMLY SPACED PERFORATIONS PER FOOT OF PIPE INSTALLED WITH PERFORATIONS OF BOTTOM OF PIPE • . PROVIDE CA~ AT UPSTREAM END OF PIPE .• SLOPE AT 2% TO OUTLET PIPE •. OUTLET PIPE TO BE CONNECTED TO ' SUBDRAIN PIPE WITH TEE OR ELBOW. . NlTE:: 1. TR~NCH FOR OUTLET PIPES TO BE BACKFILLED WITH ON-SITE SOIL. 2~ BACKDRAINS AND LATERAL DRAINS SHALL BE LOCATED AT ELEVATION OF EVERY BENCH DRAI,N~ FIRST DRAIN LOCATED AT ELEVATION JUST ABOVE . . LOWER LOT GRADE. ADDITIONAL DRAINS MAY BE REQUIREQ AT THE ,DISCRETION OF THE SOILS ENGINEER AND lOR E'NGI,NEERING ~EOLOG(ST. FILTER MATERIAL SHALL BE OF THE FOLLOWING SPECIFICATION OR AN APPROVED EOUIVALENT: SIEVE SIZE PERCENT PASSING 1 INCH 100 3/4 INCH 90-100 3/8 INCH 40-100 NO.4 25-40 NO.8 18-33 NO. 30 5-15 NO. 50 0-1 NO.2DD 0-3 GRAVEL SHALL BE OF THE FOLLOWING SPECIFICATION OR AN APPROVED EPUIVALENT: . SIEVE SIZE PERCENT 'PASSING 1 112 INCH.o 100 NO~ 4 50 NO. 200 . 8 -. SAND EOUIVALENT: MINIMUM OF 51 .' FILL OVER. NATURAL DETAIL SIDEHILL FILL COMPACTED FILL TOE OF SLOPE AS SHOWN ON GRADING PLAN PROVIDE A 1:1 MINIMUM PROJECTION FROM DESIGN TOE OF SLOPE TO TOE OF KEY ",,, 't~F.\" \. U"SU\1~6~ ~ ~ AS SHOWN ON AS BUILT NATURAL SLOPE TO BE RESTORED WITH ~ o~ calJ.1l"l • .........--~\(f I\\\y~ 'II H' MINIIIU II , ~so\\..· ~ 1/ 1!1l~G:. "to ~ . PJ/\WI/\\v1I \\'1 j\ 1-t\~ Y ~ I ~ . ~. ~r~ 7l V/\\\lII\: ,~ , 0#0------~, . .,e.:MINIMUM ~ . . J NOjE: 1. WHERE THE NAtURAL, SLOPE APPROACHES OR EXCEE'DS THE BENCH WIDTH MAY VARY 15" MINIMUM KEY WIDT OESIGN SLOPE RATIO. SPECIAL RECOMMENDATIONS WOULD BE " -u . 2'X 31 'MINIMUM KEY DEPTH PROVIDED BY THE SOILS ENGINEER. r » -I m m G) I en 2· MINIMUM IN BeDROCK OR APPROVED MATERIAL. I 2~ THE NEED FOR AND DISPOSIl"IONOF DRAINS WOULD BE DETE:RMINED BY THE SOILS ENGINEER BASED UPON EXPOSED CONDITIONS. FILL OVER' CUT DETAIL CUT/FILL CONTACT MAINTAIN MINIMUM .15' FILL SECTION FROM 1. AS SHOWN ON GRADING PLAN BACK CUT TO FACE OF FINISH SLOPE ._-------- 2. AS SHOWN ON AS' BUILT H ORIGINAL TOPOGRAPHY .... , ,"' II~ BEDROCK OR APPROV~'D MATERIAL -0 r » -I' m m G) I '-l LOWEST BENCH WIDTH 15' MINIMUM OR H/2 COMPAtTED FILL 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. lJ r » '-I m tTl Gl I en 5T ABILIZA TION FILL FOR UNSTABLE MATERIAL , ' EXPOSED IN PORTION OF CUT SLOPE REMOVE: UNSTABLE MATEijlAL ~ NATURAL SLOPE / , i~ ... _ L(,{:il·H I "'12" "'t": ypADE .~ c9j1 OR APPROVED MATERIAL REMOVE: UNSTABLE MATERIAL - -;-,;---~. MINIMUM TILTED BACK ' " -I; i "'11\'~1 ' . ...-._' _. w ~ IF RECOMMENDED BY THE SOILS ENGIN,EER AND/OR ENGINEERING .~ GEOLOGIST. THE RE,MAINING CUT PORTION OF THE SLOPE MAY tG:c n.';'u->'I"I'·· ~1' 3 " REaUI~E REMOVAL' AND REPLACEMENT WITH COMPACTED FILL. NOTE: 1. SUBDRAINS ARE NOT REQUIRED UNLESS SPECIFIED BY SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST, 2. ·Wr SHALL DE EQUIPMENT WIDTH US') FOR SLOPE HEIGHTS LESS THAN 25 FEET. 'FOR SLOPES GREATER' THAN 25 FEET -W-SHALL BE DETERMINED BV THE PROJECT SOILS ENGINEER AND lOR ENGlNEEillNG GEOLOGIST. AT NO TIME SHALL ·W· BE LESS THAN H/2. '~ S; -t rTJ, . m' e> I lD SKIN FILL OF' 'NATURAL'GROUND , 15· MINIMUM TO BE MAINTAINED FROM PROPOSED FINISH SLOPE FACE TO BACKCUT PROPOSED FINISH SLOPE ITHY ~j)}f7~ l"'"',/ ~, * 3' MI~IMUM KEY DEPTH ~ 'WJWA'~\\'AA:,x;w. ORIGINAL SLOPE ,/ ·NOTE:,1. THE NEED AND DISPOSITION OF DRAINS WILL BE DETERMINED! BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST BASED ON FIELD CONOIT.IONS. .2. PAD OVEREXCAVATION AND RECOMPACTION SHOULD BE PERFORMED IF DETERMINED TO BE NECESSARY BY THE SOILS ENGINEER ANDIOR ENGINEERING GEOLOGIST. ·1 1 i :u r ~ rn m Gl I --'" 0, DAYLIGHT CUT LOT DETAIL RECONSTRUCT COMPACTED FILL SLOPE AT 2:1 OR FLATTER (MAY INCREASE OR DECREASE"PAD AREAl. OVEREXCAVATE AND RECOMPACT --- REPLACEMENT FILL AVOID AND/OR CLEAN UP SPILLAGE OF MATERIALS ON THE NATURAL SLOPE / ~ ~ ~ NOTE: 1. SUBDRAIN AND KEY WIDTH REQUIREMENTS WILL BE DETERMINED BASED ON EXPOSED SUBSURFACE CONDITIONS AND THICKN~SS OF OVE'RBUROEN~ . 2; PAD OVER EXCAVATION AND RECOMPACTU1N SHOULD BE PERFORMED IF DETERMINED NECESSARY BY' , . . . THIi. SOILS ENGINEER AND/OR THE eNGINEERING GEOlOGIST. TRANSITION LOT DETAIL CUT LOT (MATERIAL TYPE TRANSITION) , ---- ,PAD GRADE TYPICAL BENCH ING CUT-FILL LOT (OA YUGHT TRANSITION) PAD GRADE NOTE: * DEEPER OVEREXCAVATION MAY BE RECOMMENDED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST IN STEEP CUT-FILL TRANSITION AREAS. .'. ,PLATE' EG-11· SETTLEMENT PLATE AND RISER DETAIL 2'X 2'X 1/4· STEE·L PLATE STANDARD 311.-PIPE' NIPPLE WELDI:O TO TOP OF PLATE. ~---J-_ 3/4· X S"GALVANIZED PIPE, StANDARD PIPE TH READS TOP AND BOTTOM. EXTENSIONS THREADED ON BOTH ENOS AND ADDED IN 5' INCREMENTS. 3 INCH SCHEDU LE 40 PV,C PIPE SLEEVE., ADD IN S'INCREMENTS WITH GLU~ JOINTS. FINAL GRADE 1: i I I I ...J...y.. .,..,v- I I 5' I I I ' I MAINTAIN 5' CLEARANCE OF HEAVY EQUIPMENT. -1.J\,,-MECHANICALLY HAND COMPACT IN 2'VERTICAL .,.-'\r LIFTS OR ALTERNATIVE SUITABLE TO AND ~ I ACCEPTED BY THE SOILS ENGINEER. .. 5' PI I 5' I / 1 MECHANICALLY HAND COMPACT THE INITIAL 5" " VERllCA~ WITHIN A 5' RADIUS OF PLATE BASE • / I ./ ;' , . ..... . ./ / NOTE: " " , :_: .. -,.: ,': ,:-,' -'. '. 'e' --. BOTTOM OF CLEANOUi . . ...... . .......... -.. PROVIDE A MINIMUM l' BEDDING OF COMPACTED SAND 1, LOCATIONS OF SETTLEMENT PLATES SHOULD BE CLEARLY MARKED AND READILY VISIBLE (RED FLAGGED! TO EQUIPMENT OPERATORS, 2. CONTRACTOR SHOULD MAINTAIN CLEARANCE OF A S'RADIUS OF PLATE BASE AND WITHIN 5' (VERTICAL] FOR HEAVY EQUIPMENT. FILL WITHIN CLEARANCE AREA 'SHOUl,D BE HAND'COMPACTED TO PROJECT SPECIFICATIONS OR COMPACTED ,BY ALTERNATIVE APPROVED BY THE SOILS ENGINEER. 3. AFTER S'(vERTICAL] OF FILL IS IN PLACE. CONTRACTOR SHOULD MAIN'TAIN A S.:.RADIUS EQUIPMENT CLEARANCE FROM RISER. 4. PLACE AND MECHANICALLY HAND COMPACT INITIAL 2' OF FILL PRIOR TO ESTABllSH·ING THE INITIAL READING. ' 5, IN THE EVENT OF DAMAGE TO THE SETTLEMENT PLATE OR EXTE:NSION 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 Ai' THE DISCRETION OF THE SOILS ENGINEER. ' 'PLATE EG-14 I TYPICAL SURFACE SETTLEMENT MONUM·ENT FlNISH GRADE • ---~-... ",,"-'''''' ~---3/8-DIAMETER X 6-LENGTH CARRIAGE BOLT OR EQUIVA.LENT ... -14-6-'DIAMETER X 3 112" LENGTH HatE - -3"-6- " - . -CONCRETE BACKRll - ~t- PLATE EG-15 TEST PIT SAFETY DIAGRAM SIDE VIEW .::::::::::::: TEST PIT .. ::::::::::::::::.: ..... . -.:.:.'.:.: ... .. .. .. :.:.: ..... ( NOT TO SCALE ) TOP VIEW 100 FEET I. 50 FEET . ----FLA~ . SPOIL PILE -/ ... 'FLAG APPROXIMATE CEHTER ~ CF TEST PIT o In ,Ir { NOT TO SCALE ) SO F£ET ' -'- I I PLATE ES;""16 OVERSIZE ROCK DISPOSAL VIEW NORMAL TO SLOPE FACE PROPOSED FINISH GRAD E 10' MINIMUM IE) c:::sQ . r:;I:J 00 co ~ 15' MINIMUM IAJ (B' 00 \:)-.ca 00 20'MINIMUM 0 IS) oc:a c::O QQ co 00 Qo(f) ViEW PARALLEL TO SLOPE FACE PROPOSED FINISH GRADE 10' MINIMUM IE) }J 00' MAX IMUM (B\..i • ~ 3' MINIMUM (G' c:J 0::>00, 15· MINIMUM <::ClC:IclC O::JCCIIO~ ,c:::::J 15· MINIMUM l17hi~~~~m.,.~~¥~ .' ,. BEDROCK OR APPROVED. MATERIAL NOTE: IA) ONE EQUIPMENT WIDTH OR A MINIMUM OF 15 FEET. . (B) HEIGHT AND WIDTH MAY VARY DEPENDING ON ROCK SIZE AND TYPE OF . EQUIPMENT. LENGTH OF WINDROW SHALL BE NO GREATER THAN 100' MAXIMUM. IC) IF APPROVED BY THE SOILS ENGINEER ANDIOR ENGIN.EERING GEOLOGIST, . WINDROWS MAY BE PLACED DIRECTLY ON COMPETENT MATERIAL OR, BEDROCK PROVIDED ADEQUATE SPACE IS AVAILAB.LE FOR COMPACTION. :- (0) ORIENTATION OF WINDROWS MAY VARY BUT SHOULD eE AS RECOMMENDED BY THE SOILS ENGINEER ANDIOR ENGINEERING GEOLOGIST.' STAGGE.RING OF WINDROWS IS NOT NECESSARY UNLESS RECOMMENDED. . IE) CLEAR AREA FOR UTILITY TRENCHES, FOUNDATIONS AND SWIMMING POOLS. IF) ALL FILL OVER AND AROUND ROCK WINDROW SHAL.L BE COMPACTED. TO 90% RELATIVE COMPACTION OR AS RECOMMENDED.' " . IG) AFTER FILL BETWEEN WINDROWS IS PLACED AND COMPACTED WITH THE LIFT OF FILL COVERING WINDROW, WINDROW SHOULD BE PROOF ROLLED WITH A 0-9 DOZER OR EQUIVALENT. VIEWS ARE DIAGRAMMATIC ONLY.' ROO< SHOULD NOT TOUCH AND VOIDS SHOULD BE COMPLETELY FILLED IN. 'PLATE RD-1 . ROCK DISPOSAL PITS VIEWS ARE DIAGRAMMATIC ONLY. ROO< SHOULD NOT TOUCH AND VOIDS SHOULD 8E COMPLETELY FILLED IN. . FILL LIFTS COMPACTED OVER ROCK AFTER EMBEDMENT ,-----------I I I r--- I 1 COMPACTED FILL I I I I I -----~--, I I SIZE OF EXCAVATION TO BE : COMMENSURATE WITH ROCK SIZE· I I I ROCK DISPOSAL LAYERS GRANULAR SOIL TO FILL VOIDS. '.) . . FCOMPACTED FILL DENSIRED BY FLOODING ~-- -.-----..... LAYER ONE ROCK HIGH Oo~a .............. . _ ..... ---~-.......... ---~ PROPOSED FINISH GRADE P'ROFILE ALONG LAYER '. FILL SLOPE ICLEARZONE 20' M.INIMUM LAYER ONE ROCK HIGH PLATE RD-2 , , 5 .. LEGEND: ABBREVIA nON: PP WV W DESCRIPTION: = POWER POLE = WATER VALVE = WATER = SEWER SITE VICINITY MAP NOT TO SCALE S SHH FH EP CL RIW AC FNC DWY EUC FL = SEWER I1AN HOLE = fiRE HYDRANT = EDGE OF PA VING = CENTERLINE = RIGHT Of WAY = ASPHALT = FENCE = DRIVEWAY = EUCAL YPTUS TREE = fLOW LINE ~ = SEWER LA TERAL = WA TER LA TERAL ---_ .. ------ ----,S---- W---- I>CXl -----,---SL -,---- ~------~------ RIW SUBDIVISION BOUNDARV PARCEL LiNE SEWER HAIN WATERHAIN OVERHEAD POWER LINE FIRE HYDRANT SEWER LA TERAL WA TER SERVICE GRAPHIC SCALE 40 0 20 40 80 160 '.,"'',-'-""7,,·~,,-,,-E=;2 ' !~l .. ·· _I~~'~~I' I (IN FEET) fiNCH = 40 FEET / ,. (303+ FS) (278± INV " / // 1/ // / / • / " EXIST. SEWER //' / / / / / / - / /' /' /' /' /' /' / Black· Rail Ridge Tentative"lVIap SUBDIVISION # 03-.. ' City 0" Carlsbad Tract No. PRELlI1INARY REVIEW -PRE 02-50 OWNER/SUBDIVIDER: PACIFIC COAST DEVELOPI1ENT SEWER NOTES: 7,.~------- I EXISTING SEWER TO REI'IAIN. Tj EXISTING SEWER HANHOLE TO BE REI10VED. ~ NEW SEWER DROP HANHOLE TO BE CONSTRUCTED OVER EXISTING PIPE. 4 NEW STANDARD SEWER HANHOLE. ~ EXISTING 8" PVC SEWER HAIN TO BE REI10VED AND REPLACED A T LOWER GRADE, 6 EXISTING 8" PVC SEWER HAIN TO REI1AIN, It , 60.00' ULTIMATE RIGHT-Or-WAY p4",-0.0",0,--' ""UL""Tl""M A",TE't'-P A",VE",tO"--,,,WccO TH,,-,-----/ ~ NEW 8" PVC SEWER HAIN @ 5=0, 0040. 'A EXISTING SEWER LA TERAL TO BE CONNECTED TO NEW SEWER HAIN, \2 NEW 6" PVC SEWER LA TERAL @ s=O. 0100. EARTHWORK ESTIMA TE EXCA VA TlON: C. Y. COI1FACTED FILL: C. Y. IHPO.7T: C. Y. OVEREX. 8 RECOI1PACTlON: C. Y. NOTES: EASEI1ENTS PLOTTED PER CHICAGO TITLE COI1PANY PRELlI1INARY TITLE REPORT # 23048569, DATED 6-6-03. UNDERGROUND II1PROVEI1ENTS PER CITY OF CARLSBAD II1PROVEI1ENT DWG. No. 335-5 FOR BLACK RAIL ROAD, ~ /' L_ \ \ \ [Ol[[~[JU'S[ 9.50 32.00' PAVED WIDTH I 0,50'\ 20,00 12.00 PROPOSED L SIDEWALK -"" 2% 2% (NON-CONTlGUOUs)l~dL~~~~~F-~2I--\" I PROPOSED IMPROVEME~ ~ AC, CURB, GUTTER, STREET LIGHT AND SIDEWALK. afu TYPICAL SECllON STREET "A" (PUBUC) LEGEND Artificial fill -undocumented FUTURE ® Quaternary terrace deposits, circled , where buried . • , ~ TP~6 Approximate location of exploratory , I..a.J TO=1' I. test pit ',' ' . -1-----,30 .. ------~ ~T__-16··-----1-----,14··--- 4,5' --h ~---+-20' I -5,5' '" ST, LiGHT (TYP.),----~ FIRE HYDRANT (TYP,},-------,:n -7'--:! NEW AC PA VEl1ENT ~ L Ex, AC PAVEI1ENT 2%_ ~,,/.r--'l'Li~.~.;:rl 2% ~~ ..h~ " -::::===__ _ ===:---_ ~ '\>>' ---J / U ~~EX. AC SWALE To BE REI10VED -~ 4" PCC SIDEWALK (TYP.) TYPE "G" CURB 8 GUTTER (TYP.) TYPICAL SECTION: aLA CK RAIL ROAD -·-------------PESWENiiXLSTREET (PUBLlC)- Ti=6,0 567 SAN NICOLAS DR" SUITE 320 NEWPORT BEACH, CA 92660 949-644-8900 LEGAL DESCRIPTION: THE NORTH HALF OF THE NORTHEAST QUARTER QF THE SOUTHEAST QUARTER OF SOUTHWEST QUARTER Of SECTION 22, TOWNSHIP 12 SOUTH, RANGE 4 WEST SAN BERNADWO BASE AND I1ERIDIAN, IN THE CITY Of CARLSBAD, COUNTY OF SAN DIEGO, STA TE OF CALIfORNIA STATE Of CALIfORNIA, ACCORDING TO OfFICIAL PLA T THEREOF, DESCRIBED AS FOLLOWS: EXCEPTING THEREfROI1: PARCEL I CONDEI1NED TO THE CITY OF CARLSBAD (POINSETTIA LANE), IN THE FINAL ORDER OF CONDEI1NA TlON, A CERTIFIED COpy OF WHICH RECORDED SEPTEI1BER 20, 1999 AS FILE NO. 1999-0541155, OFFICIAL RECORDS, SAN DIEGO COUNTY, TOGETHER WITH THAT PORTION OF SAID SECTION 22, LYING BETWEEN THE SOUTHERLY SIDELINE OF THE HEREINABOVE DESCRIBED PARCEL I, AND THE WESTERL Y SIDLINE Of SAID BLACK RAIL ROAD AND THE ARC OF A 25,00 FOOT RADIUS CUHVE CONCA VE SOUTHWESTERLY, SAID CURVE BEING TANGENT TO EACH OF THE LAST TWO I1ENTIONED LINES. NOTES: GEOTECHNICAL MAP Plate 1 w.O.401S-A-SC DATE 9/03 SCALE 1"=40' PREPARED BY.' Enginee!1ng Prifessiona! Civil Engineers and Lalld S urvryors TENTA T/VE TRACT MAP 1----4----------------------~-----------+----+----r----r--~ LEGENO, NOTES, TYPICAL SECTIONS, VICINITY HAP 1----+----·---------.--------I~-_4--1__-_+_-___I INITIAL DA TE INITIAL CITY APPROVAL PACIFIC COAST DEVELOPMENT 567 SAN NICHOLAS DRIVE SUITE }2fr,(-:'p NEWPORT BEACH, CA 92660 949644-8900