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HomeMy WebLinkAboutCDP 00-16; POINSETTIA LANE REACH E; GEOTECHNICAL INVESTIGATION; 1999-09-08otr ao -' GEOTECHNICAL INVESTIGATION POINSETTIA LANE ("REACH E") CARLSBAD, CALIFORNIA PREPARED FOR HUNSAKER AND ASSOCIATES SAN DIEGO, CALIFORNIA SEPTEMBER 1999 GEOCON INCORPORATED I GEOTECHNICAL CONSULTANTS Project No. 06314-12-01 1 September 8, 1999 I Hunsaker and Associates I 10179 Huennekens Street San Diego, California 92121 I Attention: Mr. Ray Martin Subject: POINSETTIA LANE ("REACH E") I CARLSBAD, CALIFORNIA GEOTECI-1NICAL INVESTIGATION Gentlemen: I In accordance with our Proposal No. LG-99202 and your authorization, we have performed a l geotechnical investigation of the proposed Poinsettia Lane ("Reach E") extension in Carlsbad, California. The proposed Poinsettia Lane alignment will extend from its present terminus at approximate Station 176+70 southerly to approximately Station 195+80 for a distance of I approximately 1,910 feet. The accompanying report presents the results of our study and conclusions and recommendations I pertaining to the geotechnical aspects of constructing the roadway as presently proposed. Provided the recommendations of this report are followed, the site is considered suitable for roadway development as currently planned. I If you should have any questions regarding this report, or if we may be of further service, please contact the undersigned at your convenience. I Very truly yours, I ffOCON INCORPORATED 41 k-M-icjhael hapi Paul Dunster RG6761 CEG 1778 CEG 1149 GE 2248 PD:AS:MSCn 1/0 D ED ED 1 AU (4) Add CERTIFIED eAon lij CHAPINt.C, 'CEG1149EETNI __ EERING 6960 Flanders Drive I an alifornia 921 e(858) 558-69 0 I * TABLE OF CONTENTS PURPOSE AND SCOPE ............................................................................................................... 1 SITE AND PROJECT DESCRIPTIONS ....................................................................................... 1 SOIL AND GEOLOGIC CONDITIONS.......................................................................................2 3.1 Undocumented Fill (unmapped) .......................................................................................... 2 3.2 Previously Placed Fill (Qpf) ................................................................................................ 2 3.3 Topsoil (unmapped).............................................................................................................2 3.4 Alluvium (Qal) ............................................... . ...................................................................... 3 3.5 Santiago Formation (Ts) ...................................................................................................... 3 3.6 Geologic Structure ............................................................................................................... 4 GROUNDWATER ......................................................................................................................... 4 GEOLOGIC HAZARDS ................................................................................................................. 4 5.1 Faulting and Seismicity .......................................................................................................4 5.2 Liquefaction.........................................................................................................................5 GEOTECIINICAL CONSIDERATIONS .....................................................................................5 6.1 Slope Stability .......................................................... .. ........................................................... 5 6.2 Alluvium Settlement .................................................................... . .......... ..............................6 CONCLUSIONS AND RECOMMENDATIONS.. ....................................................................... 7 7.1 General ................................................................................................................................. 7 7.2 Soil and Excavation Characteristics ....................................................................................7 7.3 Groundwater ................................................. .......................................................................8 7.4 Grading................................................................................................................................8 7.5 Slope Stability ................................................ . ..................................................................... 9 7.6 Settlement Considerations .................................................................................................. 11 7.7 Earthwork Grading Factors. ................................................................................................ 11 7.8 Preliminary Pavement Section ............ . ............................................................................... 11 7.9 Slope Maintenance ............................................................................................................. 12 7.10 Drainage ............................................................................................................................. 12 7.11 Grading Plan Review.........................................................................................................13 LIMITATIONS AND UNIFORMITY OF CONDITIONS MAPS AND ILLUSTRATIONS Figure 1, Vicinity Map Figure 2, Geologic Map (Map Pocket) Figure 3, Geologic Cross-Section A-A' Figure 4, Geologic Cross-Section B-B' Figure 5, Geologic Cross-Section C-C' Figure 6, Typical Buttress Detail Figure 7, Typical Stability Fill Detail Figure 8, Fill Slope Stability Analysis Figure 9, Surficial Slope Stability Analysis TABLE OF CONTENTS (Continued) APPENDIX A FIELD INVESTIGATION Figures A-i—A-il, Logs of Trenches Figures A-12--A-18, Logs of Borings APPENDIX B LABORATORY TESTING Table B-I, Summary of Direct Shear Test Results Table B-Il, Summary of Laboratory Maximum Dry Density and Optimum Moisture Content Test Results APPENDIX C EQFAULT COMPUTER ANALYSIS Table C-I, Soil Strength Parameters APPENDIX D RECOMMENDED GRADING SPECIFICATIONS I ii I I 1 I I I I I I I I I I I I I I GEOTECHNICAL INVESTIGATION 1. PURPOSE AND SCOPE This report presents the results of a geotechnical investigation for the proposed Poinsettia Lane ("Reach E") Extension. The proposed extension is located between the existing roadway terminus of approximate Station 176+70 and Station 195+80, in Carlsbad, San Diego County, California (Figure 1). The purpose of this report was to evaluate surface and subsurface soil and geologic conditions along the proposed alignment and, based on those conditions, to provide recommendations pertaining to the geotechnical aspects of improving the roadway as proposed. The scope of this geotechnical investigation consisted of performing a geologic reconnaissance, excavating 11 backhoe trenches and 3 large-diameter boreholes, and geologic mapping. The approximate locations of the exploratory excavations are depicted on the Geologic Map, Figure 2. Logs of the exploratory excavations are presented in Appendix A. Laboratory tests were performed on selected samples to evaluate their pertinent physical properties. Details of the field investigation and laboratory tests are presented in Appendices A and B, respectively. The recommendations presented herein are based upon an analysis of observations made during this investigation, results of laboratory tests, data analysis and experience with similar soil and geologic conditions. 2. SITE AND PROJECT DESCRIPTIONS The proposed Poinsettia Lane ("Reach E") extension is located in Carlsbad, California and consists of approximately 1910 feet of future roadway. The alignment is bounded to the west by an existing segment of Poinsettia Lane and extends through property currently undeveloped or utilized for agriculture. Topographically, the site consists of three north-sOuth to northeast-southwest-trending ridges separated by low-lying areas. The site ranges in elevation from a high of approximately 285 feet Mean Sea Level (MSL) at the top of a proposed cut slope at approximate Station 185+00 to a low of approximately 185 feet MSL. Surface drainage within the proposed alignment is generally to the southwest. More than half of the proposed alignment is currently used for horticultural/nursery-related activities. The extreme western end of the alignment is currently a storm-water catch basin. The deepest natural Project No. 06314-12-01 - 1 - September 8, 1999 11 I [1 I I I I I H I I I I I I I I I I I drainage channel that traverses the proposed alignment between approximate Stations 190+00 and 1 191+00 has been declared ajurisdictional wetland and thus no exploratory excavations were made n this area. A greenhouse, partially ruined shacks, fences, debris, and overhead power lines were noted along the alignment and large amounts of trash were observed, especially in the south. I 3. SOIL AND GEOLOGIC CONDITIONS Four surficial soil types and one geologic formation underlie the roadway alignment. The surficial I units include undocumented fill, previously placed fill, topsoil, and alluvium. The formational unit encountered was the Eocene-aged Santiago Formation. The soil types and geologic formations are discussed below in order of increasing age. I 3.1 Undocumented Fill (unmapped) I Undocumented fill was not observed in the exploratory excavations but may exist. This is common where agricultural activities may have masked the presence of such soils. All undocumented soil fill in areas of planned improvements should be removed and properly recompacted. Debris consisting of wood and other organics, plastics, old machinery and equipment, trailers, shacks, construction and I household waste present over large areas of the site should be removed and properly disposed off-site. 3.2 Previously Placed Fill (Qpf) I Previously placed compacted fill was encountered in exploratory Trenches T-7 and T-8, at the toe of the embankment below the existing segment of Poinsettia Lane and adjacent to the roadway at the western end of the project. The placement and compaction characteristics of this fill were described by Pacific Soils Engineering in a report entitled Final Project Grading Report, Poinsettia Hill, Building Pads 1 through 43, including Recreation Area Building pad, and Basketball Court Area, I Carlsbad Ct. 93-3, the City of Carlsbad, California, dated May 19, 1998, and by Geotechnics Incorporated in a report entitled As-Graded Geotechnical Report Aviara Phase III Carlsbad, California, dated June 25, 1998. The fill encountered during this investigation generally consists of I medium dense, moist, silty, fine sand. 1 3.3 Topsoil (unmapped) I Topsoil-approximately 1 to 2 feet thick generally blankets much of the roadway alignment and consists of loose to medium dense, dry to damp, silty, fine sand and sandy silt. Topsoils are considered unsuitable in their present condition and will require complete removal and recompaction. I Project No. 06314-12-01 -2- September 8, 1999 I I I 3.4 Alluvium (Qal) Alluvial materials were encountered within the drainage that flows approximately southwesterly between Stations 190+00 and 191+00. The alluvium generally consists of loose/caving, wet to I saturated, porous, fine and medium sand. Due to the presence of the "Jurisdictional Wetland" area we were unable to locate excavations directly under the proposed alignment. Trench T- 11 (in which I alluvium was encountered) is approximately 200 feet northeast of the toe of the proposed fill slope and 350 feet from the center line of the roadway. Observations of the alluvium in Trench T-11 I indicate that the alluvium is at least 14 feet thick. Areas of deeper alluvium may occur within this valley. In the western portion of the site, alluvium up to 11 feet thick was encountered in Trenches T-4 and T-6, consisting of loose/caving, moist to wet, sandy silt, silty sand, and silt. In the existing I catch basin, Trenches T-5 and T-6 encountered catch basin sediments up to 6 feet thick that have accumulated since the basin's construction. These deposits are loose to very loose, wet, silty sand. I The alluvium in its present condition is compressible. Alluvial deposits typically consolidate when subjected to an increase in vertical loading such as would result from filling or the placement of structural improvements. Improvements planned for areas underlain by alluvial deposits will require I special consideration such as settlement monitoring, surcharge fills and/or removal and recompaction of those soils not affected by the presence of groundwater. 3.5 Santiago Formation (Ts) The Eocene-aged Santiago Formation is exposed at the surface over much of the alignment. The Santiago Formation, consists primarily of interbedded silty sandstone, sandstone, claystone, and siltstones. The sandstone units are generally 5 to 25 feet thick, massively bedded to laminated, and moderately cemented. Cementation, however, can vary from highly cemented, drill-resistant, concretionary lenses 1 foot thick to slightly cemented zones and occasional layers where the material is nearly cohesionless. The claystone and siltstone units are generally 5 to 10 feet thick and are laminated in places. A review of data from the exploratory borings indicates that "bedding plane shear" features are present within the Santiago formation. These features will adversely impact the stability of the proposed major cut slopes and will require remediation. It is anticipated that the majority of the excavation within this unit can be accomplished with conventional, moderate to heavy-duty grading equipment. Heavy ripping will be required for excavations in localized areas of highly cemented concretionary beds. Some oversized cemented chunks may be generated. Any oversized material (i.e., material greater than 12 inches in maximum dimension) will require special handling and placement as recommended hereinafter. Typically, the sandstone members of the Santiago Formation possesses moderate R-Value I characteristics for the roadway in either an undisturbed and/or properly compacted condition. The claystone and siltstone portions of the formation, however, are generally weaker, moderately to I Project No. 06314-12-01 -3 - September 8, 1999 I highly expansive and exhibit very low R-Value characteristics. In general, highly expansive soils should be placed in deeper fill areas and away from the face of slopes. 3.6 Geologic Structure The geologic structure of the site is generally characterized by a gently southwestwardly- and northwesterly-dipping to horizontal series of Eocene sediments. Due to the shallow-dipping and undulatory nature of the sediments, it is difficult to accurately predict the outcrop pattern that will result following construction of the proposed cut slopes. A significant structural aspect of the sedimentary rocks is the occurrence of "bedding place shear" features. These zones are characterized in places by soft clay gouge zones as well as planar, smooth and polished bedding planes. The significance of these features and measures to mitigate their potential adverse effects on graded slopes are discussed hereinafter. 4. GROUNDWATER Wet to saturated alluvium was observed at the northern end of the proposed roadway extension. And in the deepest drainage (Stations 190+00 to 191+00). The exploratory trenches encountered saturated deposits at depths varying from 0 to 17 feet below ground surface. The subsurface water levels should be expected to vary widely depending on the antecedent rainfall. Seepage was observed in Borehole B-i at depths of 30, 37, and 48 feet and in B-3 at depths of 27 and 35 feet. Similar, localized seeps should be expected at exposed shear zones, geologic contacts and joints. 5. GEOLOGIC HAZARDS 5.1 Faulting and Seismicity A review of geologic literature, experience with the soil and geologic conditions in the general area, and observations during the field investigation indicate that no active faults are located at the site. The nearest known active fault is the Rose Canyon Fault Zone located approximately 6 miles west of the site. Maximum Credible and Maximum Probable seismic events of Magnitude 6.9 and Magnitude 5.7, respectively, are postulated for the Rose Canyon Fault Zone. I The estimated Maximum Credible and Maximum Probable peak site accelerations are 0.32 g and - 0.16 g, respectively. Seismic parameters for some other regional faults capable of generating ground acceleration at the site are summarized below. I I Project No. 06314-12-01 -4- September 8, 1999 I [i I I I I I I I I I I I I I TABLE 5.1 DETERMINISTIC SITE PARAMETERS FOR SELECTED FAULTS Fault Name Distance From Site (miles) Maximum Credible Event Maximum Probable Event Maximum Credible (Mag.) Peak Site Acceleration (g) Maximum Probable (Mag.) Peak Site Acceleration (g) Rose Canyon 6 6.90 0.32 5.70 0.16 Newport-Inglewood-Offshore 9 6.90 0.25 5.80 0.12 Coronado Bank 22 7.40 0.17 6.30 0.08 Elsinore-Temecula 24 6.80 0.10 6.30 0.07 Elsinore-Julian 24 7.10 0.13 6.40 0.08 Elsinore-Glen Ivy 37 6.80 0.06 6.30 0.04 Earthquake Valley 40 6.50 0.04 5.70 0.02 Palos Verdes 40 7.10 0.07 6.20 0.03 It is our opinion that the site could be subjected to moderate to severe ground shaking in the event of a major earthquake along any of the above mentioned faults, however, the seismic risk at the site is not considered to be significantly different than that of the surrounding developments of similar geologic settings in the Carlsbad area. 5.2 Liquefaction Liquefaction occurs in loose cohesionless soils located below the water table that are subjected to large accelerations during strong earthquakes. The alluvial soils present within the drainage courses are mostly sandy in nature and have a high potential for liquefaction, unless remediated by surcharging and/or removal and recompaction which would reduce the liquefaction to low and nil, respectively. 6. GEOTECHNICAL CONSIDERATIONS 6.1 Slope Stability The results of the field investigation indicate the presence of adverse geologic conditions in. the general vicinity of the proposed cut slopes illustrated on the Poinsettia Lane Grading plan, Figure 2. The adverse geologic conditions encountered include remolded bedding-plane shears, weak siltstone and clay strata, and adversely dipping geologic contacts. I Slope stability analyses of these slopes was performed utilizing the SLOPE/W© computer program and parameters shown in Table C-I. The, results of the analyses are presented in Appendix C. I Project No. 06314-12-01 . -5- September 8, 1999 I I I I I I I I I I I I I I I .The cut slopes are located between approximate Stations 179+00 and 181+00 and between Stations 182+00 and 187+00 of the proposed Poinsettia "Reach E" extension. The grading plans (Figure 2) indicate a maximum cut-slope height of approximately 55 feet. Figures 3 and 4 present geologic I cross-sections through the slopes. The projected data from the exploratory borings indicate the presence of adverse conditions within all the cut slopes. Drained buttress fills are recommended for I the slopes located between stations 182+00 to 187+00 due to the presence of bedding plane shear features as observed in large-diameter Boring Nos. B-i and B-3. The buttresses for the north-facing slope should be at least 40 feet wide at the bottom with a 1:1 (horizontal to vertical) back cut. The buttress for the south-facing slope, however, should have a shear-key with a minimum width of 50 feet with a 1.5:1 (horizontal to vertical) back cut. A typical buttress detail is presented on Figure 6. A stability fill is recommended for the south facing cut slope located between station 179+00 to 181+00. Remedial grading involves the risk of failure of the temporary backcut during grading due to the high variability of geologic conditions. These uncertain conditions include the variable strength of the different material types within the formation and also variable hydrostatic pressures within the formation. Details of mitigation measures, including temporary backcut, shear key configurations, and phased I grading, are described in the Conclusions and Recommendations section. 6.2 Alluvium Settlement The amount of settlement that could occur is a function of thickness and compressibility of the layers within the alluvial deposits and depends upon the magnitude of additional vertical loading resulting from placement of fill and/or structures. The grading plan indicates that a maximum of 45 feet of fill will be placed in some portions of the proposed fill embankments. Since this area was restricted during our field investigation, the amount and duration of settlement cannot be estimated at this time. It is recommended that when practical, this area be investigated for the total depths of compressible soils, depth of groundwater, and settlement characteristics of these soils. I LI Project No. 06314-12-01 -6- September 8, 1999 Due to the probable presence of shallow groundwater within the major canyon (Station 190+00 to 1 191+00), total removal and recompaction of the alluvial soils would not be practical, and alluvium will be left in place and the embankment will be subject to settlement. I I I I I 7. CONCLUSIONS AND RECOMMENDATIONS 7.1 General 1 7.1.1 No soil or geologic conditions were encountered during this geotechnical investigation performed by Geocon Incorporated that would preclude the proposed extension of I Poinsettia Lane provided that the recommendations of this report are followed. 7.1.2 The surficial soils such as the undocumented fill, topsoil, and alluvium within planned I improvement areas will require remedial grading in the fonn of removal and recompaction. Also any debris, existing structures, and trash encountered will need to be removed and I disposed off-site. 7.1.3 Large chunks of cemented sandstone may be generated during grading and will require special handling and placement in fill areas. 7.1.4 Buttress fills will be required to stabilize the proposed cut slopes. 7.1.5 Some portions of the proposed roadway embankment are underlain by alluvial soils that I , may not be not practical to remove due to the presence of shallow groundwater. These areas will be subject to time-dependent settlement. 7.2 Soil and Excavation Characteristics I 7.2.1 The soil conditions encountered varied from low expansive sands to highly expansive silty clays derived from the Santiago Formation and alluvium. These clayey materials are highly expansive and in general should not be placed as fill in the outer 15 feet of any fill slope I face and/or within 3 feet of finish fill grade. Claystone material should be placed in the deeper portions of fill areas away from the slope zone or mixed with sandy soils to yield an Expansion Index of less than 90. 7.2.2 It is anticipated that the surficial deposits can be excavated with light effort using I conventional heavy duty grading equipment. A moderate to heavy effort is expected for excavations within the formational sedimentary units. Oversize materials in the form of I . cemented chunks and/or slabs of sandstone may be generated during excavation of portions of the Santiago Formation. Oversize rock or slabs should be broken so that no rock fragments greater than 4 feet in maximum dimension are placed in fills. Oversized rocks I should be placed in accordance with the Recommended Grading Specifications in Appendix D. It is recommended that prior to beginning grading, acceptable areas and I methods of rock disposal be designated and reserved for the placement of rock as it is encountered. I . Project No. 06314-12-01 -7- September 8, 1999 I 7.3 Groundwater 7.3.1 Groundwater was encountered within the cari'yon alluvial deposits at depths ranging between 0 to 14 feet. Seasonal fluctuations of the groundwater depth should be expected. Saturated or overly moist excavated alluvial soils will require drying and/or mixing with drier soils to facilitate proper compaction. I 7.4 Grading 7.4.1 All grading should be performed in accordance with the Recommended Grading Specifications in Appendix D and the City of Carlsbad Grading Ordinance. Where the recommendations of this section conflict with those in Appendix D, the recommendations of this section take precedence. All earthwork should be observed and all fills tested for proper compaction by Geocon Incorporated. 7.4.2 Prior to commencing grading, a preconstruction conference should be held at the site with the owner or developer, grading contractor, civil engineer and geotechnical engineer in attendance. Special soil handling and/or the grading plans can be discussed at that time. 7.4.3 Site preparation should begin with the removal of existing structures, debris, vegetation, and all deleterious material. The depth of removal should be such that material exposed in cut areas or soils to be used as fill are free of organic matter. Material generated during stripping and/or site demolition should be exported from the site. 7.4.4 All compressible surficial soil deposits (undocumented fill, alluvium, and topsoil) within I areas of planned grading should be removed to firm natural ground and properly compacted prior to placing additional fill and/or structural loads. In addition the upper portion of previously placed fill should be excavated or scarified to a sufficient depth to I expose well-compacted fill with optimum moisture content. 1 7.4.5 The alluvium removal may be limited to approximately 3 feet above the groundwater level. I 7.4.6 The actual extent of unsuitable soil removals will be determined in the field during grading by the soil engineer and/or engineering geologist. Overly wet surficial soils will require drying and/or mixing with drier soils to facilitate proper compaction. 7.4.7 After removal of unsuitable materials as recommended above is performed, the site should then be brought to final subgrade elevations with structural fill placed and compacted in layers. Prior to placing fill, the exposed natural ground surface should be scarified to 'a I Project No. 06314-12-01 -8- September 8, 1999 I 1 1 I LI I I [7] I [I] 1' depth of at least 12 inches, moisture conditioned and compacted. In general, soils native to the site are suitable for use as fill if free from vegetation, debris and other deleterious material. Layers of fill should be no thicker than will allow for adequate bonding and compaction. All fill, including scarified ground surfaces, should be compacted to at least 90 percent of the laboratory maximum dry density in accordance with ASTM Test Procedure D-1557-91, at or slightly above optimum moisture content. Fill materials with in-place density test results indicating moisture contents less than optimum may require additional moisture conditioning. 7.4.8 Oversize cemented sandstone chunks (defined as material greater than 12 inches in nominal dimension) will likely be generated during grading within the Santiago Formation. Placement of oversize materials within fills should be performed in accordance with the recommendations in Appendix D. 7.4.9 Grading operations should be scheduled to permit the placement of oversized rock and expansive soils (if encountered) in the deeper fills. Oversized rock should be placed at least 5 feet below finish grade or 3 feet below the deepest utility, whichever is greater. I 7.4.10 Grading operations should consider capping the roadway subgrade with 3 feet of granular' soils. This should provide higher R-Value subgrade soils which would reduce the required pavement section. 7.4.11 The outer 15 feet of fill slopes, measured horizontal to the slope face, should be composed of properly compacted granular "soil" fill to reduce the potential for surface sloughing. In general, soils with an Expansion Index of less than 90 will be acceptable. 7.4.12 All fill slopes should be overbuilt at least 3 feet horizontally, and cut to the design finish ' grade. As an alternative, fill slopes may be compacted by back-rolling at vertical intervals not to exceed 4 feet and then track-walking with a Caterpillar D-8 bulldozer, or equivalent, I upon completion such that the fill soils are uniformly compacted to at least 90 percent relative compaction to the face of the finished slope. I 7.4.13 All slopes should be planted, drained and properly maintained to reduce erosion. I 7.5 Slope Stability 7.5.1 The anticipated presence of near-horizontal and adversely-dipping "bedding plane shear" features in the major cut slopes located between Stations 182+00 and 187+00, will require remedial grading measures (see Figure 3, Cross-Section A-A'); It is recommended that I Project No. 06314-12-01 -9- September 8, 1999 I I I I I I I I drained buttress fills be constructed on both sides of the road. Slope stability analyses are presented in Appendix C of this report. The analyses indicate that these buttresses should have a minimum width of 40 and 50 feet for the north-facing and south-facing slopes, respectively. I 7.5.2 In addition, it is recommended that the temporary backcut of the south-facing buttress have an inclination of 1.5 to 1 (horizontal:vertical). Higher quality fill material should also be used for this buttress as discussed in Appendix C. 7.5.3 It is recommended that the backcut slopes be carefully observed and logged during the I excavation by an engineering geologist to confirm that the size of the buttress fill is adequate. I 7.5.4 The proposed buttresses and shear key fill materials should be approved by the soil engineer prior to placement. A typical buttress fill configuration, including the I recommended drainage system is presented in Figure 6. 7.5.5 Due to the variable nature of the Santiago Formation, localized slope instability of the temporary backcut of the shear key excavation could occur. The risk of instability of the temporary cut slopes may be reduced by flattening the slope of the backcut and/or constructing the shear key in segments. Those portions of the slope which become activated will likely require complete removal and replacement with properly compacted fill soil. 7.5.6 No bedding plane shear was encountered in Boring B-2 within the vicinity of the proposed south-facing cut slope located between Station 179+00 and 181+00; therefore, no deep- seated failure is anticipated for this slope. However, the potential for seepage and surficial instability may exist due to the presence of interbedding sandstone and siltstone/claystones. It is recommended that a drained stability fill be constructed along this slope. A typical stability fill detail is presented on Figure 7. 7.5.7 Slope stability analysis utilizing average drained direct shear strength parameters based on laboratory tests and experience with similar soil types in nearby areas indicates that the proposed fill slopes constructed of on-site materials should have calculated factors of safety of at least 1.5 under static conditions for both deep-seated failure and shallow sloughing conditions. Deep-seated slope stability and surficial slope stability calculations are presented on Figures 8 and 9. I Project No. 06314-12-01 _10- September 8, 1999 7.6 Settlement Considerations +-- 7.6.1 Due to the environmental restrictio s(e alluvial soils within the main canyon, located between Stations 190+00 an 101+00 ere not investigated. Therefore, we are unable to estimate the amount and duration of alluvial settlement due to construction of the proposed road embankment. 7.7 Earthwork Grading Factors 7.7.1 Estimates of embankment shrink-bulk factors are based on comparing laboratory compaction tests with the density of the material in its natural state and experience with similar soil types. Variations in natural soil density, as well as in compacted fill, render shrinkage value estimates very approximate. As an example, the contractor can compact fills to any relative compaction of 90 percent or higher of the laboratory maximum dry density. Thus, the contractor has at least a 10 percent range of control over the fill volume. Based on our experience and laboratory testing in similar geologic materials, the following earthwork factors may be used as a basis for estimating how much the on-site soils may shrink or bulk when removed from their natural state and placed in compacted fills. TABLE 7.7 Soils Unit Shrink-Swell Factors Topsoils, Colluvium, Alluvium, Undocumented Fill Soil 5% to 10% Shrinkage Santiago Formation 5% to 10% Bulk 7.8 Preliminary Pavement Section 7.8.1 Based on an assumption that the roadway will be capped with granular soils, an assumed R-Value of 30 was used to evaluate a preliminary pavement section. A Traffic Index (TI) of 8.5 has been assumed for Poinsettia Lane. Utilizing the California Flexible Pavement Design procedure, and the City of Carlsbad minimum requirements, the pavement section presented in Table 7.8 was determined. It should be noted that the pavement section is preliminary. The final pavement recommendations will be provided for City of Carlsbad approval after finish subgrade is achieved and R-Value tests are performed on the actual subgrade soils. Where the subgrade soils exhibit an R-Value of less than 12, the City of Carlsbad requires lime stabilization of the subgrade. Project No. 06314-12-01 -11 - September 8, 1999 TABLE 7.8 PRELIMINARY PAVEMENT SECTIONS Location Assumed Asphalt Concrete Class 2 Aggregate Base Traffic Index (inches) (inches) Poinsettia Lane 8.5 5 12 7.8.2 Base course material should consist of Class 2 Aggregate Base and be properly moisture conditioned and compacted to a minimum relative compaction (ASTM D1557-91) of 95 percent. The upper 12 inches of subgrade soil should also be moisture-conditioned and compacted to a minimum relative compaction of 95 percent. 7.8. Class 2 Aggregate Base and asphalt concrete should conform to City of Carlsbad Standards. 7.9 Slope Maintenance 7.9.1 Slopes that are steeper than 3:1 (horizontal:vertical) may, under conditions that are difficult to prevent and predict, be susceptible to near surface (surficial) slope instability. The instability is typically limited to the outer three feet of a portion of the slope and usually does not directly impact the improvements on the pad areas above or below the slope. The occurrence of surficial instability is more prevalent on fill slopes and is generally preceded by a period of heavy rainfall, excessive irrigation, or the migration of subsurface seepage. The disturbance and/or loosening of the surficial soils, as might result from root growth, soil expansion, or excavation for irrigation lines and slope planting, may also be a significant contributing factor to surficial instability. It is, therefore, recommended that, to the maximum extent practical: (a) disturbed/loosened surficial soils be either removed or properly recompacted, (b) irrigation systems be periodically inspected and maintained to eliminate leaks and excessive irrigation, and (c) surface drains on and adjacent to slopes be periodically maintained to preclude ponding or erosion. It should be noted that although the incorporation of the above recommendations should reduce the potential for surficial slope instability, it will not eliminate the possibility, and, therefore, it may be necessary to rebuild or repair a portion of the project's slopes in the future. 7 7.10 Drainage 7.10.1 Establishing proper'tiâi') imperative to reduce the potential for differential soil movement, erosion andstfl5urface seepage. Positive measures should be taken to properly finish grade the improvements so that drainage water is directed away from pavement and the tops of slopes into controlled drainage devices. Even with these provisions, a shallow Project No. 06314-12-01 -12- September 8, 1999 I I [1 I I I I I I I I I I I 1 I I I I I I I I I I I I I I 'I I I I I I I I I groundwater or subsurface condition can and may develop in areas where no such condition existed prior to site development. This is particularly true where a substantial increase in surface water infiltration results from an increase in landscape irrigation. 7.11 Grading Plan Review 7.11.1 The geotechnical engineer and engineering geologist should review the grading plans prior to finalization to verify their compliance with the recommendations of this report and determine the necessity for additional comments, recommendations and/or analysis. FA Project No. 06314-12-01 September 8, 1999 LIMITATIONS AND UNIFORMITY OF CONDITIONS I I I I I I I I I I I I I I I I I H The recommendations of this report pertain only to the site investigated and are based upon the assumption that the soil conditions do not deviate from those disclosed in the investigation. If any variations or undesirable conditions are encountered during construction, or if the proposed construction will differ from that anticipated herein, Geocon Incorporated should be notified so that supplemental recommendations can be given. The evaluation or identification of the potential presence of hazardous or corrosive materials was not part of the scope of services provided by Geocon Incorporated. This report is issued with the understanding that it is the responsibility of the owner, or of his representative, to ensure that the information and recommendations contained herein are brought to the attention of the architect and engineer for the project and incorporated into the plans, and the necessary steps are taken to see that the contractor and subcontractors carry out such recommendations in the field. The findings of this report are valid as of the present date. However, changes in the conditions of a property can occur with the passage of time, whether they be due to natural processes or the works of man on this or adjacent properties. In addition, changes in applicable or appropriate standards may occur, whether they result from legislation or the broadening of knowledge. Accordingly, the findings of this report may be invalidated wholly or partially by changes outside our control. Therefore, this report is subject to review and should not be relied upon after a period of three years. Project No. 06314-12-01 September 8, 1999 I I I I I I 1 I I I I I I I I I I I I 6' E) / J 4 rF 9_\ PALOtIAR FA7 \ I q 1500 11512 CT mi SIUAR \7 IIR SNT~PE SWAOLTA, !4~'i GO DRr lyktCH TER Y4Rk A'Ru 22 BLVD >- ~INSE CA1 23 2— nor / CMUO BE LAS RD Al Cr ok 9 2r ELIA R PA JT R 28 \ \c *S L. IIADA , W R TE 3 GA ' Ay - I AVIDAISY FOXGLOVE V't4 AVIAR.4 / 'rç" 4 o 1OOu •.4 TOLF °r:D 4 I BEGONIA CT ( MLLQJ I IRIS Cr TO DR 64 CT Cr LO CT ATE 4Tt Cr j ,LOr Is SS fr \' S4 DR - - cr ioui s 34 - - BIRD. - —4 - B-Tui J.- SOURCE: 1999 THOMAS BROTHERS MAP SAN DIEGO COUNTY, CALIFORNIA REPRODUCED WITH PERMISSION GRANTED BY THOMAS BROTHERS MAPS. THIS MAP IS COPYRIGHTED BY THOMAS BROS.MAPS. IT IS UNLAWFUL TO COPY OR REPRODUCE ALL OR ANY PART THEREOF, WHETHER FOR PERSONAL USE OR RESALE WITHOUT PERMISSION NO SCALE GE000N 0 INCORPORATED GEOTECHNICAL CONSULTANTS 6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121- 2974 PHONE 858 558-6900 - FAX 858 558-6159 PD/TA DSKID000D VICINITY MAP POINSETTIA LANE - ("REACH E") CARLSBAD, CALIFORNIA DATE 09-08-1999 IPROJECT NO. 06314- 12-01 1 FIG. I 14YA / QQQ POINSETTIA LANE ("REACH E") CARLSBAD, CALIFORNIA POINSETTIA LA STA. 184 + 58 A A' 300' EXISTING GROUND r 300' B-i 260- 0 I- > w .1 W 220'- FAULT 2.0 rrcurutu (AUt ES \ BUTTRESS \ 40' Ts 50' Ih- 260' F— 220' Ts 180' - L__ 180 CROSS-SECTION A-A' SCALE: 1" = 40' (HORIZ. = VERT.) LEGEND Ts ...... SANTIAGO FORMATION GE000N ow) INCORPORATED GEOTECHNICAL CONSULTANTS 6960 FLANDERS DRIVE- SAN DIEGO, CALIFORNIA 92121-2974 PHONE 858 558-6900 - FAX 858 558-6159 PROJECT NO. 06314-12-01 FIGURE 3 DATE 09-08-1999 I I I I I I I I I I 1 I I I I I I . I I • POINSETTIA LANE ("REACH E") CARLSBAD, CALIFORNIA B B' 300'- EXISTING GROUND - 300' POINSETTIA LANE STA. 179 + 92 z 260'- PROPOSED GRADE 0 I- > w Ts 15' __ STABILITY Ts MIN. FILL 220'- -220' Ts 180' - 180' CROSS-SECTION B-B' SCALE: 1" = 40' (HORIZ. = VERT.) LEGEND Ts ...... SANTIAGO FORMATION GEOCON (Vol) INC 0 RPO RATED GEOTECHNICAL CONSULTANTS 6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121-2974 PHONE 858 558-6900 . FAX 858 558-6159 • PROJECT NO. 06314-12-01 FIGURE 4 DATE 09-08-1999 14XB I RSS I C I 26O'- I 220' 0 Lu 180' I I F POINSETTIA LANE ('REACH E") CARLSBAD, CALIFORNIA I I POINSETTIA LANE STA. 190 + 62 PROPOSED GRADE - ----------------------- EXISTING GROUND PROPOSED FILL Ts Qal Qal — -------------- - -- - - -- Qal Ts —? — - - Ts I I C, r 260' 220' 800' Li 140' Ts 140' I CROSS-SECTION C-C' 1 SCALE: 1" = 40' (HORIZ. = VERT.) I LEGEND III Qal....ALLUVIUM Ts ...... SANTIAGO FORMATION GE000N 0 INCORPORATED I GEOTECHNICAL CONSULTANTS 6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121-2974 PHONE 858 558-6900 - FAX 858 558-6159 PROJECT NO. 06314- 12-01 FIGURE 5 DATE 09-08-1999 OOI'+A,I flOO 'I EXISTING GROUND SURFACE NO SCALE 1......EXCAVATE BACKCUT AT 1.5:1 INCLINATION SUCH THAT THE KEY WIDTH AT FINISHED PAD GRADE IS AS SPECIFIED BY THE SOIL ENGINEER 2......BASE OF BUTTRESS FILL TO BE 5 FEET (OR AS DETERMINED BY SOIL ENGINEER) BELOW ADJACENT PAD GRADE SLOPING A MINIMUM 2% INTO SLOPE 3.....BUTTRESS FILL TO BE COMPOSED OF PROPERLY COMPACTED GRANULAR SOIL WITH MINIMUM SHEAR STRENGTH PARAMETERS OF (t)=30°, C=300psf ..... INSTALL PREFABRICATED CHIMNEY DRAINS PANELS (MIRADRAIN, TENSAR, OR EQUIVALENT) SPACED APPROXIMATELY 30 FEET CENTER TO CENTER. ADDITIONAL DRAINS WILL BE REQUIRED WHERE AREAS OF SEEPAGE ARE ENCOUNTERED. ..... FILTER MATERIAL TO BE 1-INCH, OPEN-GRADED CRUSHED ROCK ENCLOSED IN APPROVED FILTER FABRIC (MIRAFI 140N OR EQUIVALENT). - 6......COLLECTOR PIPE TO BE 4-INCH MINIMUM DIAMETER, PERFORATED, THICK-WALLED PVC SCHEDULE 40 OR EQUIVALENT, AND SLOPED TO DRAIN AT 1 PERCENT MINIMUM TO APPROVED OUTLET. I TYPICAL BUTTRESS DETAIL I GE000N (low) INCORPORATED GEOTECHNICAL CONSULTANTS 6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121-2974 PHONE 619 558-6900 . FAX 619 558-6159 PD/GBP REV /DFL BUTFIL3 IX-IXVIIIIRSS I I 1 I I I I I I I 1 I I I I I I 1 I 1.5' MIN 4. iv..... DETAIL NOTES: POINSETTIA LANE ("REACH E") CARLSBAD, CALIFORNIA DATE 09-08-1999 1 PROJECT NO. 06314- 12-01 1 FIG 6 10, SEE NOTE 7 FINISHED SLOPE NOTE1 NOTE 2 NOTE 4 NOTE 4 F FINISHED GRADE UNDISTURBED NOTE 6 SEE DETAIL 15' FORMATIONAL NOTE 5 Min. SOIL 2" J 15 Mm. NO SCALE DETAIL NOTES: 1 ...... EXCAVATE BACKCUT AT 1:1 INCLINATION. 2......BASE OF STABILITY FILL TO BE 3 FEET INTO DENSE, FORMATIONAL SOILS SLOPING A MINIMUM 5% INTO SLOPE. 3.....STABILITY FILL TO BE COMPOSED OF PROPERLY COMPACTED GRANULAR SOIL WITH MINIMUM SHEAR STRENGTH OF 4 30°, C'= 300 psf. 4......WHERE SEEPAGE IS ENCOUNTERED IN BACKCUT, CHIMNEY DRAINS TO BE APPROVED PREFABRICATED CHIMNEY DRAIN PANELS (MIRADRAIN, TENSAR, OR EQUIVALENT) SPACED APPROXIMATELY 20 FEET CENTER TO CENTER. ADDITIONAL DRAINS WILL BE REQUIRED WHERE AREAS OF GREATER SEEPAGE ARE ENCOUNTERED. 5 .....FILTER MATERIAL TO BE 1-INCH OPEN-GRADED CRUSHED ROCK ENCLOSED IN APPROVED FILTER FABRIC. 6.....COLLECTOR PIPE TO BE 4-INCH MINIMUM DIAMETER, PERFORATED, THICK-WALLED PVC SDR 21 OR EQUIVALENT, AND SLOPED TO DRAIN AT 1 PERCENT MINIMUM TO APPROVED OUTLET. CHIMNEY DRAINS MAY BE REQUIRED IF AREAS OF ACTIVE SEEPAGE ARE ENCOUNTERED. 7BACKCUT TO BE AT LEAST 10 FEET BEYOND SLOPE FAILURE SURFACE OR FACE OF SLOPE WHICHEVER IS GREATER. LOCATION OF BACKCUT TO BE DETERMINED BY GEOTECHNICAL CONSULTANT IN THE FIELD. TYPICAL STABILITY FILL DETAIL GE000N (low) INCORPORATED GEOTECHNICAL ENGINEERS AND ENGINEERING GEOLOGISTS 6970 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121- 2974 PHONE 858 558-6900 - FAX 858 558-6159 [: AS / GBP DSK I G0000. STABFILF/ RSS 1/ixix I I I I I I I I I I 1 I I I I I I I I POINSETTIA LANE ("REACH E") CARLSBAD, CALIFORNIA DATE 09-08-1999 I PROJECT NO.06314 -12-01 I FIG 7 PROJECT NO. 06076-12-01 ASSUMED CONDITIONS: Slope Height Slope Inclination Total Unit Weight of Soil Angle of Internal Friction Apparent Cohesion No Seepage Forces H =55 feet 2:1 (Horizontal :Vertical) 130 pounds per cubic foot 4) = 30 degrees C = 300 pounds per square foot - ANALYSIS: = 'yH tanb Equation (3-3), Reference 1 C FS = NdC Equation (3-2), Reference 1 yH = 13.8 Calculated Using Eq. (3-3) Ncf = 40 Determined Using Figure 10, Reference 2 FS = 1.6 Factor of Safety Calculated Using Eq. (3-2) REFERENCES: Janbu, N., Stability Analysis of Slopes with Dimensionless Parameters, Harvard Soil Mechanics, Series No. 46, 1954. Janbu, N., Discussion of J.M. Bell, Dimensionless Parameters for Homogeneous Earth Slopes, Journal of Soil Mechanics and Foundation Design, No. 5M6, November 1967. FILL SLOPE STABILITY ANALYSIS POINSETTIA LANE ("REACH E") CARLSBAD, CALIFORNIA FIGURE 8 I I PROJECT NO. 06076-12-01 I I I I I I I I I I I I I I I I ASSUMED CONDITIONS: Slope Height H = Infinite Depth of Saturation Z = 3 feet Slope Inclination 2:1 (Horizontal :Vertical) Slope Angle i = 26.5 degrees Unit Weight of Water 1w = 62.4 pounds per cubic foot Total Unit Weight of Soil 130 pounds per cubic foot Angle of Internal Friction 4) = 30 degrees Apparent Cohesion C = 300 pounds per square foot FIGURE 9 Slope saturated to vertical depth Z below slope face. Seepage forces parallel to slope face ANALYSIS: FS = C+(7 —y)Zcos2i tan Ø = 2.52 rt zsmicosi REFERENCES: Haefeli, R. The Stability of Slopes Acted Upon by Parallel Seepage, Proc. Second international Conference, SMFE, Rotterdam, 1948, 1, 57-62. Skempton, A. W., and F. A. Delory, Stability ofNatural Slopes in London Clay, Proc. Fourth International Conference, SMFE, London, 1957,2,378-81. SURFICIAL SLOPE STABILITY ANALYSIS POINSETTIA LANE ("REACH E") CARLSBAD, CALIFORNIA I . - -. - -- - 'S ---,*v'':"I- , i- -1 .5- I' I I -1 , ,,:,,;~~ , ~ ,, . - , - , I , , ~. ,~- 'j_ ~ , - _ 1. , - ':__ dlllll I 11 -I " ' _4 I - I ~;M~~, -i~',',;, rv~- .." .,I I I - I 1. I "~~ ii.-:0 --- - --- :,~,-,~, 1.11 ~, - --* ~,,.~-,:,-~,. -,.- ,--~, 1~ 1-1,1", . -PE N D "' I - 1 - - - . - jl~ ~, .~, . , ,;~ ~ , , . - , . ~ , : ,'-,, , , , , , ~ ~ , ., ,; ~- ,i I -: • -- I 11 - -r -.,---- -_'; .'-. ;_- ,I : : -5 4 '5 4. 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'5 I 1. 1 c:- 1 - '5 - -- I . - .5-5-..-- ,1'i 'S r 5- - - -- - 1' - 4'..' .5-.', - .4- _4 5-. - -' - _"- - ,'.' - .4. -. - _. - -- . ., - 1.•-.-_ - .1 II -- ,5- 5- -. -r - 'S - '5- - 5, 5- 'v.5- 4-.- 5-- - _ - S 5 5 4 - 'S 'S .5 4 -4 'S ' - I 4 .5- 5-- - e •..;- - 4.5 -. 'S .. I - . 4. 5.. 555--I " I 'S ' :.'I-:--.'4.-'5.''S.'S.:!J... 'r2' %'. i r -' 'S 5- 'S 5- .4' 4 'S - L - I - APPENDIX A FIELD INVESTIGATION The field investigation was performed August 5, and 17, 1999, and consisted of a visual site reconnaissance, the excavation of 11 backhoe trenches, and 3 large-diameter boreholes. The approximate locations of the exploratory excavations are shown on Figure 2. The backhoe trench was advanced depths ranging from 4 to 17 feet using a JD 555 track-mounted backhoe equipped with a 24-inch-wide bucket. The large-diameter borings were advanced to depths ranging from 36 to 65 feet below existing grade using an EZ-BORE-E120 truck-mounted drill rig equipped with a 30-inch-diameter bucket auger. Relatively undisturbed samples were obtained by driving a 3-inch split tube sampler 12 inches into the "undisturbed" soil mass with the drill rig Kelly bar. The sampler was equipped with 1-inch by 25/8-inch brass sampler rings to facilitate sample removal and laboratory testing. Bulk and chunk samples were also obtained. Borings were "downhole logged" by our geologist. The soils encountered in the exploratory excavations were visually examined, classified, and logged. Logs of the backhoe trench and borehole logs are presented on Figures A-i through A-I 8. The logs depict the soil and geologic conditions encountered. Project No. 06314-12-01 September 8, 1999 PROJECT NO. - 06314-12-01 BORING B 1 CD o I— r 0W • 0 .- \• w DEPTH IN SAMPLE o o SOIL CLASS '' . ._. FEET NO.3: Z H (U S) ELEV. (MSL.) 287 DATE COMPLETED 8/17/99 CD EQUIPMENT BUCKET AUGER WHO MATERIAL DESCRIPTION TOPSOIL - Loose, dry, yellowish brown, Silty, fine SAND - SANTIAGO FORMATION 2 - - :F•:: Medium dense, dry to damp, yellowish gray to light - :•J•:r: gray, Silty, fine and medium SANDSTONE, - 4 - :1: moderately weathered, scattered, cemented nodules up - to 1 foot diameter, random discontinuous joints up to 1/4' wide, black silt filled; slightly weathered below 7 DJJ .)1V1 feet 6 B1-2 • 8 - - ______ -Fault: N45W/445W; poorly defined fault at 9 feet 10 - :1:.: Medium dense/dense, damp, yellowish gray and very B1-3 :1:1: pale orange, Silty, fine and medium SANDSTONE 6/6' - B14 Bedding: N24E/1ONW, poorly defined sandstone - 12 laminae at 11 feet 14 • :[: B1-5 ::E: SM 5/6" 116.4 7.0 16 - • -Cross bedding: N30W/345W 18 20 - 22 - Cross bedding: N34E/24NW - - 24 B1-6 7 26 - B1-7 : - 28 - - figure A-i, Log of Boring B 1 PSL SAMPLE SYMBOLS SAMPLING UNSUCCESSFUL U ... STANDARD PENETRATION TEST I ... DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE Y ... WATER TABLE OR SEEPAGE I NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I PROJECT NO. 0.1-12-01 CD I— BORING B1 0Ci "DEPTH SAMPLE NO. o ELEV. (MSL.) 287 DATE COMPLETED 8/17/99 I— Li C\ (I)" Z - FEET (USCS) HO LU CD EQUIPMENT BUCKET AUGER X00 JL 0 _____ MATERIAL DESCRIPTION -30 - - - : ML SANTIAGO ,FORMATION (Cont.) - 32 - Dense, damp, light brown, dark yellowish orange and - yellowish gray, fine Sandy SILTSTONE, laminated, - - B1-8 \ slightly weathered, upper contact at 30' dips / 8 - 34 - B1-9 \ N66W/11SW; very slight seepage at contact / - Dense, damp, mottled yellowish gray, dark yellowish ;M/ML orange, Silty, fine SANDSTONE/Sandy SILTSTONE - 36 - - 38 - Faulted contact at 37 feet, fault: N75E/40NW - Bi-10 7 98.3 25.9 - 131-11 4H/CL bedding plane shear undulatory to planar, 1" soft - - 40 - gouge, bedding up to 1 foot below is sheared parallel to bedding; bedding: N30W/10SW, slight seepage at fault. - 42 - 'J'r' Stiff, damp, olive gray to dark greenish gray, - CLAYSTONE/SILTSTONE, moderately to slightly - weathered - 44 - Contact: N50E/5NW at 41 feet SM Dense, damp, yellowish gray, mottled dark yellowish - - orange, massive, slightly weathered, Silty, fine - 46 - - SANDSTONE - -48 - - - Dense, damp, olive gray SILTSTONE with sand, - B1-13 ML micaceous, laminated; undulatory, approximately flat 10 108.1 18.1 50 - B1-14 - - lying upper contact, with very slight seepage - -Bedding: N1OE/6W, poorly defined laminae - 52 - -. - -Massive - - 54 flat lying gradational contact - 56 - SM Dense, damp, light gray, Silty, fine SANDSTONE, 15/8" slightly weathered to unweathered; 1/2" thick ash bed - - at 56 feet; bedding: N35W/5SW - - - - 58 - FHure A-2. Lo of Boring B 1 I NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I I - - -7 --- -- - -- -PSL SAMPLE SYMBOLS U ... SAMPLING UNSUCCESSFUL IJ ... STANDARD PENETRATION TEST U .. DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE 10 ... CHUNK SAMPLE Y ... WATER TABLE OR SEEPAGE I I I I I I I I I 1 I 1 I J PROJECT NO. 06314-12-01 BORING B1 DEPTH SOIL H- H' IN SAMPLE CLASS ELEV. (MSL.) 287 DATE COMPLETED 8/17/99 cn Li.. w ... FEET (USCS) WHO 0C) cn H I- EQUIPMENT BUCKET AUGER IL 0 C) _____ MATERIAL DESCRIPTION 60 - SANTIAGO FORMATION (Cont.) Dense, damp, light gray to yellowish gray, mottled - 62 - ::E:: dark yellowish orange, slightly weathered, Silty, fine • :::::F SM SANDSTONE 64 :f: -End visual log at 64 feet BORING TERMINATED AT 65 FEET Figure A-3. Figure Loc! of Boring B 1 I -7 ---a -- - - PSI I NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I SAMPLE SYMBOLS 0 ... SAMPLING UNSUCCESSFUL C ... STANDARD PENETRATION TEST N ... DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE Y . . . WATER TABLE OR SEEPAGE I I I I I I I I I I I I I I I PROJECT NO. 06314-12-01 CD I— BORINGB2 DEPTH SAMPLE SOIL o. _, . w>• FEET NO. ELEV(us . (MSL.) 267 DATE COMPLETED 8/17/99 EQUIPMENT BUCKET AUGER 0 MATERIAL DESCRIPTION 0 - ____ ____ _____________________________________________ _____ _____ _____ - SANTIAGO FORMATION - Dense, dry, moderately weathered, yellowish gray, 2 - ::: Silty, fine SANDSTONE, joints up to 1/16" wide, soil - :•:: and root filled approximately vertical, less than 6" - spacing, stained black 4 - - - : -Joints rare below 4 feet - 132-1 SM -Bedding: N34E/6NW, siltstone laminae 5 110.1 8.8 6 132-2 • 8 - • -6" wide zone of poorly defined siltstone laminae, - 10 undulatory, lenticular, spaced 1/4" -Becomes yellowish gray, slightly weathered from 11 - 12 feet - 14 16 - - -Undulatory flat lying contact - Stiff, damp, grayish olive, laminated, slightly - MH weathered elastic SILTSTONE, mottled yellows, 18 - laminae poorly defined, lenticular - 20 - - - - 132-5 RSM -Bedding: N20E/14W - siltstone laminae 3 - — -Gradational contact - - 22 - Very dense, damp, yellowish gray, slightly weathered SILTSTONE with sand, massive - - 24 - ML -6" thick laminated zone, siltstone laminae undulatory, - - - • approximately flat lying - 26 - - 28 132-7 • -Grades to silty sand below 30 feet - 8/10" 116.9 14.4 - - B2-8 • Figure A-4.. Log of Boring B 2 Boring - 1L SAMPLING UNSUCCESSFUL IJ ... STANDARD PENETRATION TEST I ... DRIVE SAMPLE (UNDISTURBED) SAMPLE SYMBOLS DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE Y ... WATER TABLE OR SEEPAGE I NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. 1 PROJECT NO [IT1rsJI BORINGB 2 DEPTH IN SAMPLE Z SOIL CLASS LL W FEET NO. (USC ) ELEV. (MSL.) 267 DATE COMPLETED 8/17/99 wj z H 0 EQUIPMENT BUCKET AUGER wH • -' Hp cz z 0 0 MATERIAL DESCRIPTION 30 SANTIAGO FORMATION (Cont.) - 32 - ;' Dense, damp, mottled dark yellowish orange and light - IX SM gray, very poorly defined, undulatory, approximately - flat lying laminae, Silty, ,fine and medium 34 - f• SANDSTONE - -End visual log at 34 feet - B2-9 10/8" 36 - BORING TERMINATED AT 36 FEET rigure A-b, Log 01 isoring is PSLN I SAMPLE SYMBOLS 0 ... SAMPLING UNSUCCESSFUL II ... STANDARD PENETRATION TEST I ... DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I I I I I I I PROJECT NO 06314-12-01 BORINGB3 CD I- i- DEPTH IN SAMPLE o z SOIL CLASS HI- t\ ZL H' FEET NO. (USCS) ELEV. (MSL.) 278 DATE COMPLETED 8/17/99 acn w _j W W EQUIPMENT BUCKET AUGER 'H o Z (n MATERIAL DESCRIPTION TOPSOIL Loose, damp, yellowish brown, Silty, fine to medium - - 2 - SAND SANTIAGO FORMATION Dense, damp, yellowish gray to pale yellowish orange, - - 4 - Silty, fine SANDSTONE, massive - 6 - - 8 - - 10 - SM - • :::::: 12 14 - - 16 - -Bedding: N5W/6SW, 6" thick zone with siltstone - - - laminae, 1/4" spacing - 18 - - 20 - -Approximately horizontal siltstone laminae, - - - undulatory - -Mottled dark yellowish orange -- 22 - - ::E::: -Bedding: N60E/21NW, well defined sandstone - - 24 - laminae in 1 foot thick zone - - - undulatory, approximately horizontal contact 26 -Bedding plane shear, soft, plastic, wet, 1/4" thick clay seam horizontal - 4H/CL Stiff, damp, moderate brown, elastic SILTSTONE, 28 - poorly defined laminae, approximately horizontal, - undulatory, defined by yellow streaks, scattered, - smooth laminae Fhure A-6. Lo of Boring B 3 I NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I. - I - -- -7 -- - -- -PSL 0 ... SAMPLING UNSUCCESSFUL IJ ... STANDARD PENETRATION TEST U ... DRIVE SAMPLE (UNDISTURBED) SAMPLE SYMBOLS DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE ... WATER TABLE OR SEEPAGE PROJECT NO 06314-12-01 BORINGB3 D I- zr)- H - DEPTH IN SAMPLE 3 Z SOIL CLASS I: zLL. FEET NO. H 0 ELEV. (MSL.) 278 DATE COMPLETED 8/17/99 cn w 1 CD EQUIPMENT BUCKET AUGER wHo w wco H1... 1:0 MATERIAL DESCRIPTION 30 - - SANTIAGO FORMATION (Cont.) 32 - 4H/CL -Planar, smooth, 1/16" thick, bedding: N-S/SE - -Becomes olive gray -34- - - Dense, damp, dark yellowish orange, light gray, 36 - ::E: yellowish gray, Silty SANDSTONE, laminated, slightly - B31 ::t SM weathered, bedding well defined - -Seepage along bedding at 35 feet 38 - • ::: 40 - - - -Bedding: N74E/10SE - - - 42 - - - ::E:3::' -End visual log - - 44 - - BORING TERMINATED AT 45 FEET Figure A-7. LOOf Boring II 3 -- F'SL 0 ... SAMPLING UNSUCCESSFUL IJ ... STANDARD PENETRATION TEST I ... DRIVE SAMPLE (UNDISTURBED) SAMPLE SYMBOLS DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE Y ... WATER TABLE OR SEEPAGE I NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I I I I 111 I I I I I PROJECT NO. 06314-12-01 TRENCH T 1LD DEPTH SOIL . Hz.— - IN SAMPLE o 0 Z CLASS ELEV. (MSL.) 231 DATE COMPLETED 8/5/99 Z u- \ u CnLL Z w EQUIPMENT JD 555 MATERIAL DESCRIPTION 0 - - LL - ____ TOPSOIL T ___ Loose, dry, moderate yellowish brown, Silty, fine 2 Ti-i SM SAND - SANTIAGO FORMATION ______ Dense, very pale orange, Silty, fine SANDSTONE, 4 slightly weathered, scattered roots up to 1/8" - \ diameter TRENCH TERMINATED AT 4 FEET Figure A-S. Lo of Trench T 1 I NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I I - -7 -- -- -- - -PSL SAMPLE SYMBOLS 0 ... SAMPLING UNSUCCESSFUL LI ... STANDARD PENETRATION TEST I ... DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE Y ... WATER tABLE OR SEEPAGE PROJECT NO. 06314-12-01 TRENCH T 2 CD I— Cz Hh- " DEPTH IN SAMPLE a a Z SOIL CLASS E\ ZI1 NO. ELEVFEET (USCS). (MSL.) 208 DATE COMPLETED 8/5/99 1 cn w LD EQUIPMENT JD 555 MATERIAL DESCRIPTION SM - TOPSOIL ,_ \ Loose, dry, moderate yellowish brown, mottled - 2 - \ dark yellowish orange, Silty, fine SAND - SANTIAGO FORMATION - - SM - Dense, dry, very pale orange, Silty, fine - 4 - SANDSTONE, slightly weathered, scattered roots - up to 1/8" diameter to 3.5 feet TRENCH TERMINATED AT 4.5 FEET Figure A-9. Log of Trench T 2 F 10 SAMPLE SYMBOLS 0 ... SAMPLING UNSUCCESSFUL III ... STANDARD PENETRATION TEST N ... DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE ... WATER TABLE OR SEEPAGE I NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. PROJECT NO 06314-12-01 TRENCH T 3 DEPTH CD I- SOIL IN NO. o = C3 '' ELEV. (MSL.) 203 DATE COMPLETED 8/5/99 C\ U) ZLL. w .. FEET (USCS) i-... LIJwO o CnW CD EQUIPMENT JD 555 Lu ca W'-' E o_ •-' (_) • MATERIAL DESCRIPTION - SM REFUSE: plastics, pipes, batteries and wood mixed - 1- I withsoil - 2 - -\ TOPSOIL — - - \ Loose, dry, moderate yellowish brown, Silty, fine _f F sp \ SAND - 4 - :•:::•' ____ SANTIAGO FORMATION - Dense, dry, very pale orange, mottled dark \ yellowish orange, poorly graded fine SANDSTONE TRENCH TERMINATED AT 4.5 FEET Figure A-b. Log of Trench T 3 -- -----7 --•- -- ---— - rL 1 r SAMPLING UNSUCCESSFUL 11 ... STANDARD PENETRATION TEST I ... DRIVE SAMPLE (UNDISTURBED) SAMPLE SYMBOLS ... DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE Y ... WATER TABLE OR SEEPAGE I NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I PROJECT NO 06314-12-01 tigure A-il, Log of 'trench '1' 4 I SAMPLE SYMBOLS ... SAMPLING UNSUCCESSFUL II ... STANDARD PENETRATION TEST I ... DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. PSLN TRENCH T4 H DEPTH IN SAMPLE 0 = Z SOIL CLASS - Z - FEET NO. (USCS) ELEV. (MSL.) 229 DATE COMPLETED 8/5/99 U wj z CD EQUIPMENT JD 555 WHO Ho 0 0 MATERIAL DESCRIPTION -- - TOPSOIL T4-1 - ML Stiff, dry to moist, dark yellowish brown, fine, 2 T4-2 - Sandy SILT ' - -.:ALLUVIUM - - - Loose, moist, moderate yellowish brown, fine to - - 4-3 - IL/SM medium Sandy SILT/Silty SAND, highly porous, - scattered rootlets '6 - '8- -.- - 10 - - - 12 - ____ - SM SANTIAGO FORMATION edium dense, damp, yellowish gray, Silty, fine ANDSTONE, slightly weathered, Lnon2orous TRENCH TERMINATED AT 12 FEET I I I I I I I I I I 1 [1 I LI I I I PROJECT NO. 06314-12-01 TRENCH T 5 CD 0 I- 0W H . DEPTH SAMPLEIN NO SOIL CLASS ELEV. (MSL.) 209 DATE COMPLETED 8/5/99 I_ZLL Cfl • FEET -j (USCS) w CD EQUIPMENT J]) 555 z W ca W a- 0 Ci MATERIAL DESCRIPTION - ALLUVIUM (CATCH BASIN DEPOSITS) - - T5 1 - SM Loose to very loose, wet, grayish yellow, Silty, fine 2 and medium SAND - - 4 - SM SANTIAGO FORMATION - Medium dense, damp, mottled dark yellowish orange, very pale orange and yellowish gray, Silty, - - 6 _____ - fine and medium SANDSTONE, moderately \ abundant random discontinuous, black ~weathered, joints up to 1/16"wide, slightly d, scattered joints TRENCH TERMINATED AT 6 FEET SAMPLE SYMBOLS 0 ... SAMPLING UNSUCCESSFUL U ... STANDARD PENETRATION TEST U ... DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE Y ... WATER TABLE OR SEEPAGE I NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I - 11 I I I I I I I II I I - Figure A-12, Log of Trench T 5 PSU PROJECT NO. 06314-12-01 TRENCH T 6 . LLJ )- DEPTH SO IN SAMPLE0 NO. Z CLASS ELEV. (MSL.) 214 DATE COMPLETED 8/5/99 ccn in Z wj — z FEET (USCS)cn WHO in H EQUIPMENT JD 555 Q \d (J MATERIAL DESCRIPTION -0 - - ' ALLUVIUM (CATCH BASIN DEPOSITS) - Loose to very loose, wet, caving, grayish yellow, - 2 - 1. Silty, fine and medium SAND - - - SM - -4 - I-I -6 - - - ALLUVIUM - Loose, moist to wet, moderate and dark yellowish - 8 - brown SILT, some fine sand, porous - - 10 - T6-1 ML - - 12 - - - 14 - - 16 - - 18 - ____ - SM SANTIAGO FORMATION Medium dense, damp to wet, mottled grayish orange, Silty SANDSTONE, pale and dark yellowish orange, moderately weathered, massive, scattered, random, discontinuous black silt filled joints TRENCH TERMINATED AT 18 FEET tigure A-li, Log 0! Irencli '1 O PSLN SAMPLE SYMBOLS 11 ... SAMPLING UNSUCCESSFUL IJ ... STANDARD PENETRATION TEST U ... DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE 10 ... CHUNK SAMPLE ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I I I I I I I I I I I I I I I I PROJECT NO. 06314-12-01 TRENCH T 7 . DEPTH IN SAMPLE SOIL 0 Z: z CLASS \ • z FEET NO. (USCS) ELEV. (MSL.) 221 DATE COMPLETED 8/5/99 • CD EQUIPMENT JD 555 W HO H IL '- 0. L) MATERIAL DESCRIPTION - I- I FL Loose to medium dense, damp, mottled oranges - - 2 - :1 1.H and grays, Silty, fine to medium SAND - - T7-1 - T7-2 alt:. SM - 6 - - .1.j. -i- i81_ TRENCH TERMINATED AT 9 FEET Figure A-14. Log of Trench T 7 I - -- -- -- .PSL I NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I [1 I SAMPLE SYMBOLS El ... SAMPLING UNSUCCESSFUL IJ ... STANDARD PENETRATION TEST I ... DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE Y ... WATER TABLE OR SEEPAGE Iiigure A-1, Log ot'lrencli 1 I SAMPLE SYMBOLS SAMPLING UNSUCCESSFUL IJ ... STANDARD PENETRATION TEST I ... DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE ....CHUNK SAMPLE Y ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. PSLN PROJECT NO. 06314-12-01 TRENCH T 8 DEPTH 0 <C SOIL HF- H' IN SAMPLE NO. 0 0 2 CLASS ELEV. (MSL.) 217 DATE COMPLETED 8/5/99 C\ cn LL. w FEET H 0 w cn • LD EQUIPMENT JD 555 co '-' 0 0 MATERIAL DESCRIPTION - 0 - FILL - - . I Loose to medium dense, mottled oranges and grays, - 2 - : Silty, fine to medium SAND - -4 - - - J- SM - -.6 i 8 1_ TRENCH TERMINATED AT 9 FEET I I I I I I I 1 I I I I I I I I I TRENCHT9. w...j DEPTH IN SAMPLE a a Z SOIL CLASS L...Z , Zu_ FEET NO. (USCS) ELEV. (MSL.) 207 DATE COMPLETED 8/5/99 &w -•••• ui a - °'w CD EQUIPMENT JD 555 LLlD o_ W,_, a o MATERIAL DESCRIPTION - 0 - ____ ____ a" TOPSOIL J. 11- Loose, dry, moderate yellowish brown, Silty, fine - 2 - 1- \ SAND - SM SANTIAGO FORMATION - :1 Dense, dry, very pale orange, Silty, fine - 4 - :1. I- SANDSTONE, slightly weathered, scattered roots - up to 1/8" diameter, moderately weathered in upper 1 foot TRENCH TERMINATED AT 5 FEET 11 I I I I I I I I PROJECT NO. 06314-12-01 Figure A-16, Log of Trench T 9 PSLI U ... SAMPLING UNSUCCESSFUL IJ ... STANDARD PENETRATION TEST I ... DRIVE SAMPLE (UNDISTURBED) SAMPLE SYMBOLS DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE Y ... WATER TABLE OR SEEPAGE I NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I PROJECT NO. 06314-12-01 TRENCH T.1O DEPTH SOIL H- IN SAMPLE SAMPLE NO. o = CLASS ELEV. (MSL.) 199 ' DATE COMPLETED 8/5/99 Z H 0 wHo H EQUIPMENT JD 555 MATERIAL DESCRIPTION T1O1 TT - TOPSOIL - T10-2 I - . I SM Loose, dry, moderate yellowish brown, Silty, fine 2 - SAND - . ::• - SANTIAGO FORMATION Dense, dry, very pale orange, Silty, fine 4 . :F•.•:. SM SANDSTONE, slightly weathered, scattered roots - UP to 1/8" diameter, moderately weathered in upper 2 feet 6 TRENCH TERMINATED AT 6 FEET figure A-17, Log of 'french '1' 10 PSLN SAMPLE SYMBOLS 0 ... SAMPLING UNSUCCESSFUL El ... STANDARD PENETRATION TEST I ... DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I I I I I I I I I I I I I PROJECT NO. 06314-12-01 . w TRENCH T 1 DEPTH SOIL - H1-1 IN SAMPLE NO. Z CLASS ELEV. (MSL.) COMPLETED 8/5/99 _________DATE cn z'- wj ni.-. z FEET (USCS) H CD EQUIPMENT JD 555 W to Ix 0 ci MATERIAL DESCRIPTION - 0 - - - -: ALLUVIUM - - Loose, dry to moist, very pale orange, grayish - 2 - - sp orange, fine and medium SAND, some silt - - - - -Prevalent caving, saturated, a little seepage - - - -- -• -Seepage at 5 feet -6 - - 8 T11-1 - 10 - - - - 12 -14 - TRENCH TERMINATED AT 14 FEET DUE TO PREVALENT CAVING Figure A-iS. Lo of Trench T 11 SAMPLE SYMBOLS 0 ... SAMPLING UNSUCCESSFUL IJ ... STANDARD PENETRATION TEST I ... DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE ... WATER TABLE OR SEEPAGE I NOTE: THE LOG OF. SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I 7 - - 4 4 4 4 ? - 1 -. , '.. "' ~'. '':~ - ~' ~- " ''.''k, -,-; -'—.. APPEN 1 4";~' - '~''--.~ ~' I s ' ~ ;.~ ~~'~' ~ '' 11 - ~~ '.' ~~ " D X I , , .- - . 1, , - I I ~~ , , , - ~ - I ~ , '~ " " I ~ -. " - ' , ", , - , ., 1. . . -, *' -' '~~ " ~' ' t - ' - -- '~ ' ~ - ~ - ~ . , ~ ' - i I "J, ::~'- , i ;'~ ~' , - ~'~ , ' , .1 , ~ ~ ~ , , . . _ " , . - '~ . - , , , I , 1, t , A, APPENDIX B LABORATORY TESTING Laboratory tests were performed in accordance with generally accepted test methods of the American Society for Testing and Materials (ASTM) or other suggested procedures. Selected soil samples were tested for their in-place dry density and moisture content, maximum dry density and optimum moisture content, and shear strength characteristics. The results of our laboratory tests are presented as follows on Tables B-I and B-I!. The in-place dry density and moisture content results are indicated on the exploratory excavation logs. TABLE B-I SUMMARY OF DIRECT SHEAR TEST RESULTS ASTM D 3080 I Sample No. I Dry Density I Moisture Content I Unit Cohesion Angle of Shear I I (PC') (%) I (psi) Resistance (degrees) I 131_16* 102.6 15.4 609 35 *Sample remolded to 90 percent relative compaction at optimum moisture content. TABLE B-Il SUMMARY OF LABORATORY MAXIMUM DRY DENSITY AND OPTIMUM MOISTURE CONTENT TEST RESULTS ASTM D 1557-91 Sample No. Description Maximum Dry Density (pci) Optimum Moisture Content (% dry wt.) T4-3 Brown, Silty, fine SAND 116.9 11.5 B1-16 Grey, Silty, fine SAND 114.1 15.3 Project No. 06314-12-01 September 8, 1999 APPENDIX C SLOPE STABILITY ANALYSIS Analyses of the stability of the proposed 40- and 50-foot-high cut slopes were performed utilizing SLOPEW computer program based on the simplified Janbu method of slices.. Geologic Cross Section A-A' (Figure 3) is the original geologic Cross-Section from which the computer generated section were derived (Figure C-i). The sections are considered to represent the most critical in terms of geologic constrains and proposed grading geometry. Assumed Soil Strength Parameters The soil strength parameters utilized in the analysis of the cut slope stability, were selected from a range of values obtained in the laboratory and experience with similar soil and geologic conditions in the general vicinity. The following are the strength parameters utilized for this analysis. TABLE C-I SOIL STRENGTH PARAMETERS Material Unit Weight (pci) Cohesion (C') (psi) Friction Angle (4)) (degrees) Santiago Formation (sandstone, siltstones) 130 500 30 Fill 130 1 300 30 Fill (Selected for the south-facing buttress) 130 300 32 Bedding Plane Shear 130 100 8 The results of the analysis for both slopes indicate a factor of safety of less than 1.5 for the proposed interim grading configuration. I The analysis is based on a final critical block failure surface determined by the Modified Janbu Method. The results of our analysis indicate that the construction of a drained buttress fill (Figures 3, C-i, and C-2) will be required to achieve the desired calculated factor-of-safety in excess of 1.5 with the presently proposed grading configuration. The minimum shear key width required for the north- facing buttress at location of Cross Section A-A' is 40 feet and for the south-facing buttress is 50 feet. The analysis of the temporary backcuts indicate that the 1:1 (horizontal :vertical) inclination would be I marginally stable for the north-facing slope. The minimum inclination for the temporary backcut of the south-facing slope should be 1.5:1. In addition, this buttress should be constructed in segments no larger than 150 feet. I Project No. 06314-12-01 September 8, 1999 1 U I I Li I I I I I I I - - - - - - - - - - .— - - - - - —. = 06314-12-01 File ANorth2A.slp POINSETTA LANE (REACH E) Cross Section A-A' -South Facing Slope 50 foot Wide Buttress 1.529 Distance (feet) Figure C-I - - - - '- - - - - - —. - - - - - - '- 06314-12-01 File ASouthl.slp POINSETTA LANE (REACH E) Cross Section A-A' - North Facing Slope 40 foot Wide Buttress 1.933 300 ZOU (D Qcf : cu 220 - a) 200 180 0 50 100 150 200 250 300 350 Distance (feet) Figure C-2 - - - - - - - - - - - - - - - - - - - 06314-12-01 File ANorth2b.slp POINSETTA LANE (REACH E) Cross Section A-A' - South Facing Slope 1.5: 1 Backcut 0.925 Figure C-3 — —, — — — — — — _I — — — — — — — _.. 06314-12-01 File ASouth3.slp POINSETTA LANE (REACH E) Cross Section A-A' - North Facing Slope 1:1 Backcut 1.078 . Figure C-4 - - I I & APPENDIX 1 - APPENDIX D RECOMMENDED GRADING SPECIFICATIONS for POINSETTIA LANE ("REACH E") CARLSBAD, CALIFORNIA PROJECT NO. 06314-12-01 RECOMMENDED GRADING SPECIFICATIONS 1. GENERAL 1.1. These Recommended Grading Specifications shall be used in conjunction with the Geotechnical Report for the project prepared by Geocon Incorporated. The recom- mendations contained in the text of the Geotechnical Report are a part of the earthwork and grading specifications and shall supersede the provisions contained hereinafter in the case of conflict. 1.2. Prior to the commencement of grading, a geotechnical consultant (Consultant) shall be employed for the purpose of observing earthwork procedures and testing the fills for substantial conformance with the recommendations of the Geotechnical Report and these specifications. It will be necessary that the Consultant provide adequate testing and observation services so that he may determine that, in his opinion, the work was performed in substantial conformance with these specifications. It shall be the responsibility of the Contractor to assist the Consultant and keep him apprised of work schedules and changes so that personnel may be scheduled accordingly. 1.3. It shall be the sole responsibility of the Contractor to provide adequate equipment and methods to accomplish the work in accordance with applicable grading codes or agency ordinances, these specifications and the approved grading plans. If, in the opinion of the Consultant, unsatisfactory conditions such as questionable soil materials, poor moisture condition, inadequate compaction, adverse weather, and so forth, result in a quality of work not in conformance with these specifications, the Consultant will be empowered to reject the work and recommend to the Owner that construction be stopped until the unacceptable conditions are corrected. 2. DEFINITIONS 2.1. Owner shall refer to the owner of the property or the entity on whose behalf the grading work is being performed and who has contracted with the Contractor to have grading performed. 2.2. Contractor shall refer to the Contractor performing the site grading work. 2.3. Civil Engineer or Engineer of Work shall refer to the California licensed Civil Engineer or consulting firm responsible for preparation of the grading plans, surveying and verifying as-graded topography. GI rev. 8/98 2.4. Consultant shall refer to the soil engineering and engineering geology consulting firm retained to provide geotechnical services for the project. 2.5. Soil Engineer shall refer to a California licensed Civil Engineer retained by the Owner, who is experienced in the practice of geotechnical engineering. The Soil Engineer shall be responsible for having qualified representatives on-site to observe and test the Contractor's work for conformance with these specifications. 2.6. Engineering Geologist shall refer to a California licensed Engineering Geologist retained by the Owner to provide geologic observations and recommendations during the site grading. 2.7. Geotechnical Report shall refer to a soil report (including all addenda) which may include a geologic reconnaissance or geologic investigation that was prepared specifically for the development of the project for which these Recommended Grading Specifications are intended to apply. ' 3. MATERIALS 3.1. Materials for compacted fill shall consist of any soil excavated from the cut areas or I imported to the site that, in the opinion of the Consultant, is suitable for use in construction of fills. In general, fill materials can be classified as soil fills, soil-rock fills or rock fills, as defined below. I 3.1.1. Soil fills are defined as fills containing no rocks or hard lumps greater than 12 I inches in maximum dimension and containing at least 40 percent by weight of material smaller than 3/4 inch in size. 3.1.2. Soil-rock fills are defined as fills containing no rocks or hard lumps larger than 4 I for feet in maximum dimension and containing a sufficient matrix of soil fill to allow fill fragments hard lumps proper compaction of soil around the rock or as specified in Paragraph 6.2. Oversize rock is defined as material greater than 12 1 inches. I 3.1.3. Rock fills are defined as fills containing no rocks or hard lumps larger than 3 feet in maximum dimension and containing little or no fines. Fines are defined as material smaller than 3/4 inch in maximum dimension. The quantity of fines shall I be less than approximately 20 percent of the rock fill quantity. I I GI rev. 8/98 I 3.2. Material of a perishable, spongy, or otherwise unsuitable nature as determined by the Consultant shall not be used in fills. I 3.3. Materials used for fill, either imported or on-site, shall not contain hazardous materials as defined by the California Code of Regulations, Title 22, Division 4, Chapter 30, Articles 9 and 10; 40CFR; and any other applicable local, state or federal laws. The Consultant shall I not be responsible for the identification or analysis of the potential presence of hazardous materials. However, if observations, odors or soil discoloration cause Consultant to I suspect the presence of hazardous materials, the Consultant may request from the Owner the termination of grading operations within the affected area. Prior to resuming grading operations, the Owner shall provide a written report to the Consultant indicating that the I suspected materials are not hazardous as defined by applicable laws and regulations. I 3.4. The outer 15 feet of soil-rock fill slopes, measured horizontally, should be composed of properly compacted soil fill materials approved by the Consultant. Rock fill may extend to I the slope face, provided that the slope is not steeper than 2:1 (horizontal:vertical) and a soil layer no thicker than 12 inches is track-walked onto the face for landscaping purposes. This procedure may be utilized, provided it is acceptable to the governing agency, Owner I and Consultant. I 3.5. Representative samples of soil materials to be used for fill shall be tested in the laboratory by the Consultant to determine the maximum density, optimum moisture content, and, 'where appropriate, shear strength, expansion, and gradation characteristics of the soil. 3.6. During grading, soil or groundwater conditions other than those identified in the I Geotechnical Report may be encountered by the Contractor. The Consultant shall be notified immediately to evaluate the significance of the unanticipated condition 4. CLEARING AND PREPARING AREAS TO BE FILLED 1 4.1. Areas to be excavated and filled shall be cleared and grubbed. Clearing shall consist of complete removal above the ground surface of trees, stumps, brush, vegetation, man-made I structures and similar debris. Grubbing shall consist of removal of stumps, roots, buried logs and other unsuitable material and shall be performed in areas to be graded. Roots and other projections exceeding 1-1/2 inches in diameter shall be removed to a depth of 3 feet I below the surface of the ground. Borrow areas shall be grubbed to the extent necessary to provide suitable fill materials. I I i GI rev. 8/98 4.2. Any asphalt pavement material removed during clearing operations should be properly disposed at an approved off-site facility. Concrete fragments which are free of reinforcing steel may be placed in fills, provided they are placed in accordance with Section 6.2 or 6.3 of this document. 4.3. After clearing and grubbing of organic matter or other unsuitable material, loose or porous soils shall be removed to the depth recommended in the Geotechnical Report. The depth of removal and compaction shall be observed and approved by a representative of the Consultant. The exposed surface shall then be plowed or scarified to a minimum depth of 6 inches and until the surface is free from uneven features that would tend to prevent uniform compaction by the equipment to be used. 4.4. Where the slope ratio of the original ground is steeper. than 6:1 (horizontal:vertical), or. where recommended by the Consultant, the original ground should be benched in accordance with the following illustration. TYPICAL BENCHING DETAIL Finish Grade Ground 2 1 Finish Slope Surface Remove All Unsuitable Material As Recommended By Soil Engineer Slope To Be Such That Sloughing Or Sliding Does Not Occur Yaries See Note 1 See Note 2 No Scale DETAIL NOTES: (I) Key width "B" should be a minimum of 10 feet wide, or sufficiently wide to permit complete coverage with the compaction equipment used. The base of the key should be graded horizontal, or inclined slightly into the natural slope. (2) The outside of the bottom key should be below the topsoil or unsuitable surficial material and at least 2 feet into dense formational material. Where hard rock is exposed in the bottom of the key, the depth and configuration of the key. may be modified as approved by the Consultant. GI rev. 8/98 I I I I I I I I I I I I I I I .1 I I I I 4.5. After areas to receive fill have been cleared, plowed or scarified, the surface should be I disced or bladed by the Contractor until it is uniform and free from large clods. The area should then be moisture conditioned to achieve the proper moisture content, and compacted as recommended in Section 6.0 of these specifications. I 5. COMPACTION EQUIPMENT 5.1. Compaction of soil or soil-rock fill shall be accomplished by sheepsfoot or segmented-steel I wheeled rollers, vibratory rollers, multiple-wheel pneumatic-tired rollers, or other types of acceptable compaction equipment. Equipment shall be of such a design that it will be capable of compacting the soil or soil-rock fill to the specified relative compaction at the I specified moisture content. 5.2. Compaction of rock fills shall be performed. in accordance with Section 6.3. 1 6. PLACING, SPREADING AND COMPACTION OF FILL MATERIAL 6.1. Soil fill, as defined in Paragraph 3.1.1, shall be placed by the Contractor in accordance with I the following recommendations: I 6.1.1. Soil fill shall be placed by the Contractor in layers that, when compacted, should generally not exceed 8 inches. Each layer shall be spread evenly and shall be I thoroughly mixed during spreading to obtain uniformity of material and moisture in each layer. The entire fill shall be constructed as a unit in nearly level lifts. Rock materials greater than 12 inches in maximum dimension shall be placed in I accordance with Section 6.2 or 6.3 of these specifications. I 6.1.2. In general, the soil fill shall be compacted at a moisture content at or above the optimum moisture content as determined by ASTM D1557-91. I 6.1.3. When the moisture content of soil fill is below that specified by the Consultant, water shall be added by the Contractor until the moisture content is in the range I specified. I 6.1.4. When the moisture content of the soil fill is above the range specified by the Consultant or too wet to achieve proper compaction, the soil fill shall be aerated by the Contractor by blading/mixing, or other satisfactory methods until the moisture I content is within the range specified. I I GI rev. 8/98 El 6.1.5. After each layer has been placed, mixed, and spread evenly, it shall be thoroughly I compacted by the Contractor to a relative compaction of at least 90 percent. Relative compaction is defined as the ratio (expressed in percent) of the in-place dry density of the compacted fill to the maximum laboratory dry density as I determined in accordance with ASTM D1557-91. Compaction shall be continuous over the entire area, and compaction equipment shall make sufficient passes so that I the specified minimum relative compaction has been achieved throughout the entire fill. 6.1.6. Soils having an Expansion Index of greater than 50 may be used in fills if placed at least 3 feet below finish pad grade and should be compacted at a moisture content I generally 2 to 4 percent greater than the optimum moisture content for the material. I 6.1.7. Properly compacted soil fill shall extend to the design surface of fill slopes. To achieve proper compaction, it is recommended that fill slopes be over-built by at I least 3 feet and then cut to the design grade. This procedure is considered preferable to track-walking of slopes, as described in the following paragraph. 1 6.1.8. As an alternative to over-building of slopes, slope faces may be back-rolled with a heavy-duty loaded sheepsfoot or vibratory roller at maximum 4-foot fill height I . intervals. Upon completion, slopes should then be track-walked with a D-8 dozer or similar equipment, such that a dozer track covers all slope surfaces at least 1 . twice. 6.2. Soil-rock fill, as defined in Paragraph 3.1.2, shall be placed by the Contractor in accordance with the following recommendations: I 6.2.1. Rocks larger than 12 inches but less than 4 feet in maximum dimension may be incorporated into the compacted soil fill, but shall be limited to the area measured 15 feet minimum horizontally from the slope face and 5 feet below finish grade or 1 3 feet below the deepest utility, whichever is deeper. I 6.2.2. Rocks or rock fragments up to 4 feet in maximum dimension may either be individually placed or placed in windrows. Under certain conditions, rocks or rock fragments up to 10 feet in maximum dimension may be placed using similar I methods. The acceptability of placing rock materials greater than 4 feet in maximum dimension shall be evaluated during grading as specific cases arise and I shall be approved by the Consultant prior to placement. I I GI rev. 8/98 I 6.2.3. For individual placement, sufficient space shall be provided between rocks to allow I for passage of compaction equipment. I 6.2.4. For windrow placement, the rocks should be placed in trenches excavated in properly compacted soil fill. Trenches should be approximately 5 feet wide and 4 feet deep in maximum dimension. The voids around and beneath rocks should be 1 filled with approved granular soil having a Sand Equivalent of 30 or greater and should be compacted by flooding. Windrows may also be placed utilizing an I "open-face" method in lieu of the trench procedure, however, this method should first be approved by the Consultant. 1 6.2.5. Windrows should generally be parallel to each other and may be placed either parallel to or perpendicular to the face of the slope depending on the site I geometry. The minimum horizontal spacing for windrows shall be 12 feet center-to-center with a 5-foot stagger or offset from lower courses to next I overlying course. The minimum vertical spacing between windrow courses shall be 2 feet from the top of a lower windrow to the bottom of the next higher windrow. I 6.2.6. All rock placement, fill placement and flooding of approved granular soil in the I windrows must be continuously observed by the Consultant or his representative. 6.3. Rock fills, as defined in Section 3.1.3., shall be placed by the Contractor in accordance with I the following recommendations 1 6.3.1. The base of the rock fill shall be placed on a sloping surface (minimum slope of 2 percent, maximum slope of 5 percent). The surface shall slope toward suitable I subdrainage outlet facilities. The rock fills shall be provided with subdrains during construction so that a hydrostatic pressure buildup does not develop. The subdrains shall be permanently connected to controlled drainage facilities to 1 control post-construction infiltration of water. I 6.3.2. Rock fills shall be placed in lifts not exceeding 3 feet. Placement shall be by rock trucks traversing previously placed lifts and dumping at the edge of the currently I placed lift. Spreading of the rock fill shall be by dozer to facilitate seating of the rock The rock fill shall be watered heavily during placement. Watering shall consist of water trucks traversing in front of the current rock lift face and spraying I water continuously during rock placement. Compaction equipment with compactive energy comparable to or greater than that of a 20-ton steel vibratory roller or other compaction equipment providing suitable energy to achieve the I GI rev. 8/98 I - required compaction or deflection as recommended in Paragraph 6.3.3 shall be I utilized. The number of passes to be made will be determined as described in Paragraph 6.3.3. Once a rock fill lift has been covered with soil fill, no additional rock fill lifts will be permitted over the soil fill. 6.3.3. Plate bearing tests, in accordance with ASTh4 D1196-64, may be performed in I both the compacted soil fill and in the rock fill to aid in determining the number of passes of the compaction equipment to be performed. If performed, a minimum of I . three plate bearing tests shall be performed in the properly compacted soil fill (minimum relative compaction of 90 percent). Plate bearing tests shall then be performed on areas of rock fill having two passes, four passes and six passes of the I compaction equipment, respectively. The number of passes required for the rock fill shall be determined by comparing the results of the plate bearing tests for the I soil fill and the rock fill and by evaluating the deflection variation with number of passes. The required number of passes of the compaction equipment will be I that performed as necessary until the plate bearing deflections are equal to or less than determined for the properly compacted soil fill. In no case will the required number of passes be less than two. 6.3.4. A representative of the Consultant shall be present during rock fill operations to verify that the minimum number of "passes" have been obtained, that water is I being properly applied and that specified procedures are being followed. The actual number of plate bearing tests will be determined by the Consultanfduring I grading. In general, at least one test should be performed for each approximately 5,000 to 10,000 cubic yards of rock fill placed. 6.3.5. Test pits shall be excavated by the Contractor so that the Consultant can state that, I properly in his opinion, sufficient water is present and that voids between large rocks are filled with smaller rock material. In-place density testing will not be required in the rock fills. 6.3.6. To reduce the potential for "piping" of fines into the rock fill from overlying soil I fill material, a 2-foot layer of graded filter material shall be placed above the uppermost lift of rock fill. The need to place graded filter material below the rock should be determined by the Consultant prior to commencing grading. The I gradation of the graded filter material will be determined at the time the rock fill is being excavated. Materials typical of the rock fill should be submitted to the I Consultant in a timely manner, to allow design of the graded filter prior to the commencement of rock fill placement. 1~ I GE rev. 8/98 6.3.7. All rock fill placement shall be continuously observed during placement by representatives of the Consultant. 7. OBSERVATION AND TESTING 7.1. The Consultant shall be the Owners representative to observe and perform tests during clearing, grubbing, filling and compaction operations. In general, no more than 2 feet in vertical elevation of soil or soil-rock fill shall be placed without at least one field density test being performed within that interval. In addition, a minimum of one field density test shall be performed for every 2,000 cubic yards of soil or soil-rock fill placed and compacted. 7.2. The Consultant shall perform random field density tests of the compacted soil or soil-rock fill to provide a basis for expressing an opinion as to whether the fill material is compacted as specified. Density tests shall be performed in the compacted materials below any disturbed surface. When these tests indicate that the density of any layer of fill or portion thereof is below that specified, the particular layer or areas represented by the test shall be reworked until the specified density has been achieved. 7.3. During placement of rock fill, the Consultant shall verify that the minimum number of passes have been obtained per the criteria discussed in Section 6.3.3. The Consultant shall request the excavation of observation pits and may perform plate bearing tests on the placed rock fills. The observation pits will be excavated to provide a basis for expressing an opinion as to whether the rock fill is properly seated and sufficient moisture has been applied to the material. If performed, plate bearing tests will be performed randomly on the surface of the most-recently placed lift. Plate bearing tests will be performed to provide a basis for expressing an opinion as to whether the rock fill is adequately seated. The maximum deflection in the rock fill determined in Section 6.3.3 shall be less than the maximum deflection of the properly compacted soil fill. When any of the above criteria indicate that a layer of rock fill or any portion thereof is below that specified, the affected layer or area shall be reworked until the rock fill has been adequately seated and sufficient moisture applied. 7.4. A settlement monitoring program designed by the Consultant may be conducted in areas of rock fill placement. The specific design of the monitoring program shall be as recommended in the Conclusions and Recommendations section of the project Geotechnical Report or in the final report of testing and observation services performed during grading. I I G rev. 8/98 I I I I I I I I 1 I I I I 7.5. The Consultant shall observe the placement of subdrains, to verify that the drainage devices I have been placed and constructed in substantial conformance with project specifications. 7.6. Testing procedures shall conform to the following Standards as appropriate: 7.6.1. Soil and Soil-Rock Fills: I 7.6.1.1. Field Density Test, ASTM D1556-82, Density of Soil In-Place By the I Sand-Cone Method. 7.6.1.2. Field Density Test, Nuclear Method, ASTM D2922-81, Density of Soil and I Soil-Aggregate In-Place by Nuclear Methods (Shallow Depth). 7.6.1.3. Laboratory Compaction Test, ASTM D1557-91, Moisture-Density Relations of Soils and Soil-Aggregate Mixtures Using 10-Pound Hammer I and 18-Inch Drop. 7.6.1.4. Expansion Index Test, Uniform Building Code Standard 29-2, Expansion I Index Test. 7.6.2.. Rock Fills I 7.6.2.1. Field Plate Bearing Test, ASTM D1196-64 (Reapproved 1977) Standard Methodfor Nonrepresentative Static Plate Load Tests of Soils and Flexible I : Pavement Components, For Use in Evaluation and Design of Airport and Highway Pavements. 1 8. PROTECTION OF WORK 8.1. During construction, the Contractor shall properly grade all excavated surfaces to provide I positive drainage and prevent potiding of water. Drainage of surface water shall be controlled to avoid damage to adjoining properties or to finished work on the site. The I Contractor shall take remedial measures to prevent erosion of freshly graded areas until such time as permanent drainage and erosion control features have been installed. Areas subjected to erosion or sedimentation shall be properly prepared in accordance with the I Specifications prior to placing additional fill or structures. I 8.2. After completion of grading as observed and tested by the Consultant, no further excavation or filling shall be conducted except in conjunction with the services of the Consultant. I I I I GI rev. 8/98 fl L 9. CERTIFICATIONS AND FINAL REPORTS 9.1. Upon completion of the work, Contractor shall furnish Owner a certification by the Civil Engineer stating that the lots and/or building pads are graded to within 0.1 foot vertically of I elevations shown on the grading plan and that all tops and toes of slopes are within 0.5 foot horizontally of the positions shown on the grading plans. After installation of a section of I subdrain, the project Civil Engineer should survey its location and prepare an as-built plan of the subdrain location. The project Civil Engineer should verify the proper outlet for the subdrains and the Contractor should ensure that the drain system is free of obstructions. 9.2. The Owner is responsible for furnishing a final as-graded soil and geologic report I satisfactory to the appropriate governing or accepting agencies. The as-graded report should be prepared and signed by a California licensed Civil Engineer experienced in geotechnical engineering and by a California Certified Engineering Geologist, indicating I that the geotechnical aspects of the grading were performed in substantial conformance with the Specifications or approved changes to the Specifications. I I I I I I I 1 I I I GI rev. 8/98 I I I I I I I I I I I I I I 1 I I I - SCALE DATE 1 =40 09 08 1999 PROJECT NO 06314 12 01 FIGURE - _______ _______ APPROVED LLOYD B HUMS SHEET OF 2 ______ ______ Cmi' ENGINEER RCE 23889 EXPI2/31/O1 DATE CN OWN BY _________ PROJECT NO DRAWING NO DATE INITIAL DATE INITIAL CHKD BY PTION OTHER APPROVAL CITY APPROVAL RWW'D BY R:\0025\0025/805.DWG