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HomeMy WebLinkAboutCT 83-19; CALAVERA HILLS VILLAGE L2; UPDATE OF GEOTECHNICAL REPORT; 1999-10-15UPDATE OF GEOTECHNICAL REPORT CALAVERA HILLS, VILLAGE L-2 CITY OF CARLSBAD, CALIFORNIA FOR CYPRESS VALLEY, LLC 2727 HOOVER AVENUE NATIONAL CITY, CALIFORNIA 91950 W.O. 2748-A-SC OCTOBER 15, 1999 Geotechnical • Geologic • Environmental 5741 PalmerWay • Carlsbad, California 92008 • (760)438-3155 • FAX (760) 931-0915 October 15, 1999 W.O. 2748-A-SC Cypress Valley, LLC 2727 Hoover Avenue National City, California 91950 Attention: Mr. Thom Fuller Subject: Gentlemen: Update of Geotechnical Report, Calavera Hills, Village L-2, City of Carlsbad, California In accordance with your request, GeoSoils, Inc. (GSI) has performed a geotechnical update evaluation of the subject site. The purpose of the study was to evaluate the onsite soils and geologic conditions and their effects on the proposed site development from a geotechnical viewpoint. Unless specifically superceded in the text of this report, recommendations presented in the referenced reports (see Appendix A) are considered valid and applicable. SCOPE OF SERVICES The scope of our services has included the following: 1. Review of the referenced reports. 2. Geologic site reconnaissance. 3. General areal seismicity update evaluation. 4. Engineering and geologic analysis and preparation of this report. SITE CONDITIONS/PROPOSED DEVELOPIVIENT A site reconnaissance, performed by a representative from this office on October 13,1999, indicated that site conditions have not substantially changed since the completion of the referenced reports by others (see Appendix A). It is our understanding that planned site development will consist of site preparation for the construction of approximately 15 single family residential structures. Foundation loads are anticipated to be typical for this type of relatively light construction. Sewage disposal is anticipated to be tied into the regional system. Proposed development is shown on the attached Tentative Site Plan (Plate 1), prepared by O'Day Consultants. EARTHWORK RECOMMENDATIONS Site grading should be performed in accordance with the minimum standards of the City of Carlsbad, the Uniform Building Code (1997 edition) and the grading guidelines presented in Appendix B. Due to the anticipated rock hardness, consideration should be given to over excavating street areas to at least 12 inches below lowest utility invert elevation. Overexcavation within parkways should also be considered with respect to utility laterals. This is not a geotechnical requirement, however. SEISMIC DESIGN PARAMETERS Based on the site conditions, Chapter 16 of the Uniform Building Code (International Conference of Building Officials, 1997), the following seismic parameters are provided. Seismic zone (per Figure 16-2*) 4 Seismic Zone Factor (per Table 16-1*) 0.40 Soil Profile Type (per Table 16-J*) SB Seismic Coefficient C ^ (per Table 16-Q*) 0.40 N3 Seismic Coefficient C„ (per Table 16-R*) 0.40 N„ Near Source Factor (per Table 16-S*) 1.0 Near Source Factor N„ (per Table 16-T*) 1.0 Seismic Source Type (per Table 16-U*) B Distance to Seismic Source 7.8 mi (12.5 km) Upper Bound Earthquake M« 6.9 * Figure and table references from Chapter 16 of the Uniform Building Code (1997). SLOPE STABILITY A review ofthe referenced reports (SCST, 1984,1990) indicates that cut and fill slopes are considered grossly and surficially stable. However, due to the sometimes random nature Cypress Valley, LLC Calavera Hills, Village L-2 File: e:\wp7\2700\2748a.ugr W.O. 2748-A-SC October 15,1999 Page 2 GeoSoils, Inc. of fractures in this type of bedrock, adverse conditions may be exposed during grading. Such conditions, if present, should be evaluated by the geotechnical consultant as soon as they are exposed and the appropriate recommendations should be provided. Such an evaluation may consist of a formal slope stability analysis. Possible remedial recommendations may include, but not necessarily limited to buttress fills, stability fills, rock netting, and rock bolting. FOUNDATION RECOMMENDATIONS General The foundation design and construction recommendations presented herein are preliminary in nature and will be finalized at the-completion of grading. Recommendations for conventional foundation systems are provided in the following sections. The foundation systems may be used to support the proposed structures, provided they are founded in competent bearing material and should be designed and constructed in accordance with the guidelines contained in the Uniform Building Code. All footing designs should be reviewed by the project structural engineer. The use of conventional and/or post tensioned slab foundations will be determined in accordance with the criteria presented in the attached Table 1 and Table 2. Conventional Foundation Design 1. Conventional spread and continuous footings may be used to support the proposed residential structures provided they are founded entirely in properly compacted fill or other competent bearing material (i.e., bedrock). Footings should not simultaneously bear directly on bedrock and fill soils. 2. Analyses indicate that an allowable bearing value of 2000 pounds per square foot may be used for design of continuous footings per Table 1, and for design of isolated pad footings 24 inches square and 18 inches deep into properly compacted fill or bedrock. The bearing value may be increased by one-third for seismic or other temporary loads. This value may be increased by 20 percent for each additional 12 inches in depth, to a maximum of 2500 pounds per square foot. No increase, in bearing, for footing width is recommended. 3. For lateral sliding resistance, a 0.4 coefficient of friction may be utilized for a concrete to soil contact when multiplied by the dead load. 4. Passive earth pressure may be computed as an equivalent fluid having a density of 300 pounds per cubic foot with a maximum earth pressure of 2500 pounds per square foot. Cypress Valley, LLC W.O. 2748-A-SC Calavera Hills, Village L-2 October 15,1999 File: e:\wp7\2700\2748a.ugr Page 3 GeoSoils, Inc. 5. When combining passive pressure and frictional resistance, the passive pressure component should be reduced by one-third. 6. Footings should maintain a horizontal distance or setback between any adjacent slope face and the bottom outer edge of the footing. The horizontal distance may be calculated by using h/3, where (h) is the height of the slope. The horizontal setback should not be less than 7 feet, nor need not be greater than 40 feet (per code). The setback may be maintained by simply deepening the footings. Flatwork, utilities or other improvements within a zone of h/3 from the top of slope may be subject to lateral distortion. Footings, flatwork, and utilities setbacks should be constructed in accordance with distances indicated in this section, and/or the approved plans. 7. Provided that the recommendations contained in this report are incorporated into final design and construction phase of development, a majority (>50 percent) ofthe anticipated foundation settlement is expected to occur during construction. Maximum settlement is not expected to exceed approximately Va-inch and should occur below the heaviest loaded columns. Differential settlement is not anticipated to exceed y4-inch between similar elements, in a 20 foot span. Conventional Foundation/Concrete Slab Construction The following construction recommendations are based on generally very low to low expansive bearing soils and maximum fill thicknesses of less than approximately 50 feet. 1. Conventional continuous footings should be constructed in accordance with recommendations presented in Table 1, and in accordance with Uniform Building Code guidelines (1997 ed.). All footings should be reinforced per Table 1. 2. Detached isolated interior or exterior piers and columns should be founded at a minimum depth of 18 inches below the lowest adjacent ground surface and tied to the main foundation in at least one direction with a grade beam. Reinforcement should be properly designed by the project structural engineer. 3. A grade beam, reinforced as above, and at least 12 inches square, should be provided across the garage entrances. The base of the reinforced grade beam should be at the same elevation as base of the adjoining footings. 4. The residential floor and garage slabs should have a minimum thickness of 4 inches, in accordance with Table 1. Concrete used in floor slab construction should have a minimum compressive strength of 2000 psi. 5. Concrete slabs should be underlain with a minimum of 4 inches of sand. In addition, a vapor barrier consisting of a minimum of 10-mil, polyvinyl-chloride Cypress Valley, LLC W.O. 2748-A-SC Calavera Hills, Village L-2 October 15,1999 File: e:\wp7\2700\2748a.ugr Page 4 GeoSoils, Inc. may be integrated into the slab design or independent ofthe slab. The perimeter beams should be a minimum of 12 inches in width. A vapor barrier should be utilized and be of sufficient thickness to provide an adequate separation of foundation from soils (10-mil thick). The vapor barrier should be lapped and adequately sealed to provide a continuous water-resistant barrier under the entire slab. The vapor barrier should be sandwiched between two 2-inch thick layers of sand (SE>30) for a total of 4 inches of sand. 4. Isolated piers should be incorporated into the post tension slab system. 5. Specific soil presaturation for slabs is not required for very low expansive soils; however, the moisture content ofthe subgrade soils should be at or above the soils' optimum moisture content to a minimum depth of 18 inches below grade depending on the footing embedment 6. Post-tensioned slabs should be designed using sound engineering practice and be in accordance with the Post-Tension Institute (PTI), local and/or national code criteria and the recommendations of a structural or civil engineer qualified in post- tension slab design. Alternatives to PTI methodology may be used if equivalent systems can be proposed which accommodate the angular distortions, expansion parameters, and settlements noted for this project. If alternatives to PTI are suggested by the structural consultant, consideration should be given for additional review by a qualified structural PT-designer. Soil related parameters for post- tensioned slab design, are presented in Table 2. 7. Provided that the recommendations contained in this report are incorporated into final design and construction phase of development, a majority (>50 percent) ofthe anticipated foundation settlement is expected to occur during construction. Maximum settlement (preliminary estimate) is not expected to exceed approximately Va-inch and should occur below the heaviest loaded columns. Differential settlement is not anticipated to exceed y4-inch between similar elements, in a 20 foot span for maximum fill thicknesses up to 30 feet. Deeper fills and/or differential fill thicknesses greater than 3:1 will be evaluated on a lot by lot basis during grading, and may result in more onerous design. Designers of PT slabs should review the parameters provided for post-tensioned slabs, and compare using a span distance of 5 feet, using a modules of subgrade reaction, presented in Table 2. 8. In accordance with guidelines presented in the Uniform Building Code, improvements and/or footings should maintain a horizontal distance, X, between any adjacent descending slope face and the bottom outer edge of the improvement and/or footing. The horizontal distance, X, may be calculated by using X = h/3, Cypress Valley, LLC W.O. 2748-A-SC Calavera Hills, Village L-2 October 15, 1999 File: e:\wp7\2700\2748a.ugr Page 6 GeoSoils, Inc. where h is the height of the slope. X should not be less than 7 feet, nor need not be greater than 40 feet. X may be maintained by deepening the footings. Improvements constructed within a distance of h/3 from the top of slope may be subject to lateral distortion. Foundations for any adjacent structures, including retaining walls, should be deepened (as necessary) to below a 1:1 projection upward and away from any proposed lower foundation system. This recommendation may not be considered valid, if the additional surcharge imparted by the upper foundation on the lower foundation has been incorporated into the design ofthe lower foundation. Additional setbacks, not discussed or superseded herein, and presented in the UBC are considered valid. DEVELOPMENT CRITERIA Landscape Maintenance and Planting Water has been shown to weaken the inherent strength of soil and slope stability is significantly reduced by overly wet conditions. Positive surface drainage away from graded slopes should be maintained and only the amount of irrigation necessary to sustain plant life should be provided for planted slopes. Overwatering should be avoided. Graded slopes constructed within and utilizing onsite materials would be erosive. Eroded debris may be minimized and surficial slope stability enhanced by establishing and maintaining a suitable vegetation cover soon after construction. Plants selected for landscaping should be light weight, deep rooted types which require little water and are capable of surviving the prevailing climate. Compaction to the face of fill slopes would tend to minimize short term erosion until vegetation is established. In order to minimize erosion on a slope face, an erosion control fabric should be considered. From a geotechnical standpoint leaching is not recommended for establishing landscaping. If the surface soils area processed for the purpose of adding amendments they should be recompacted to 95 percent relative compaction. Additional Site Improvements Recommendations for additional grading, exterior concrete flatwork design and construction, including driveways, can be provided upon request. If in the future, any additional improvements are planned for the site, recommendations concerning the geological or geotechnical aspects of design and construction of said improvements could be provided upon request. Cypress Valley, LLC W.O. 2748-A-SC Calavera Hills, Village L-2 October 15, 1999 File: e:\wpA2700\2748a.ugr Page 7 GeoSoils, Inc. Trenching All footing trench excavations for structures and walls should be observed and approved by a representative of this office prior to placing reinforcement. Footing trench spoil and any excess soils generated from utility trench excavations should be compacted to a minimum relative compaction of 90 percent if not removed from the site. All excavations should be observed by one of our representatives and conform to CAL-OSHA and local safety codes. GSI does not consult in the area of safety engineers. In addition, the potential for encountering hard spots during footing and utility trench excavations should be anticipated. If these concretions are encountered within the proposed footing trench, they should be removed, which could produce larger excavated areas within the footing or utility trenches. Drainage Positive site drainage should be maintained at all times. Drainage should not flow uncontrolled down any descending slope. Water should be directed away from foundations and not allowed to pond and/or seep into the ground. Pad drainage should be directed toward the street or other approved area. Roof gutters and down spouts should be considered to control roof drainage. Down spouts should outlet a minimum of 5 feet from the proposed structure or into a subsurface drainage system. We would recommend that any proposed open bottom planters adjacent to proposed structures be eliminated for a minimum distance of 10 feet. As an alternative, closed bottom type planters could be utilized. An outlet placed in the bottom of the planter, could be installed to direct drainage away from structures or any exterior concrete flatwork. PLAN REVIEW Final site development and foundation plans should be submitted to this office for review and comment, as the plans become available, for the purpose of minimizing any misunderstandings between the plans and recommendations presented herein. In addition, foundation excavations and any additional earthwork construction performed on the site should be observed and tested by this office. If conditions are found to differ substantially from those stated, appropriate recommendations would be offered at that time. Cypress Valley, LLC W.O. 2748-A-SC Calavera Hills, Village L-2 October 15, 1999 File: e:\wp7\2700\2748a.ugr Page 8 GeoSoils, Inc. LIMITATIONS The materials observed on the project site and the referenced reports reviewed are believed to be generally representative ofthe area; however, soil and bedrock materials vary in character between excavations and natural outcrops or conditions exposed during mass grading. Site conditions may vary due to seasonal changes or other factors. GSI assumes no responsibility or liability for work, testing or recommendations performed or provided by others. The scope of work was performed within the limits of a budget. Inasmuch as our study is based upon the site materials obsen/ed, selective laboratory testing and engineering analysis, the conclusion and recommendations are professional opinions. These opinions have been derived in accordance with current standards of practice, and no warranty is expressed or implied. Standards of practice are subject to change with time. The opportunity to be of service is sincerely appreciated. If you should have any questions, please do not hesitate to contact the undersigned at (760) 438-3155. Respectfully submitted, GeoSoils, Inc. Robert G. Crisman Engineering Geologist, C RGC/DWS/JPF/mo Attachments: V. David W. Skelly Civil Engineer, RC Table 1 - Conventional Foundation Recommendations Table 2 - Post Tensioned Foundation Recommendations Appendix A - References Appendix B - General Earthwork and Grading Guidelines Plate 1 - Geologic Map Distribution: (4) Addressee Cypress Valley, LLC Calavera Hills, Village L-2 File: e:\wpA2700\2748a.ugr W.O. 2748-A-SC October 15,1999 Page 9 GeoSoils, Inc. TABLE 1 Conventional Perimeter Footings. Slabs, and Exterior Flatwork for Calavera Hills. Village L-2 FOUNDATION CATEGORY MINIMUM FOOTING SIZE INTERIOR SLAB THICKNESS REINFORCING STEEL INTERIOR SLAB REINFORCEMENT UNDER-SLAB TREATMENT GARAGE SLAB REINFORCEMENT EXTERIOR FLATWORK REINFORCING 1 12" Wide X 12" Deep 4" Thick 1-#4 Bar Top and Bottom #3 Bars @ 24" O.C Both Directions 2" Sand Over 10- Mil Polyvinyl Membrane Over 2" Sand Base 6" X 6" (10/10) WWF none II 12" Wide X 18" Deep 4" Thick 2- #4 Bars Top and Bottom #3 Bars @ 18" O.C Both Directions 2" Sand Over 10- Mil Polyvinyl Membrane Over 2" Sand Base 6" X 6" (6/6) WWF 6" X 6" (10/10) WWF III 12" Wide X 24" Deep 4" Thick 2- #5 Bars Top and Bottom #3 Bars @ 18" O.C Both Directions 2" Sand Over 10- Mil Polyvinyl Membrane Over 2" Sand Base Same as Interior Slab 6" X 6" (6/6) WWF Category Criteria Category I: Max. Fill Thickness is less than 20' and Expansion Index is less than or equal to 50 and Differential Fill Thickness is less than 10 (see note 1). Category II: Max. Fill Thickness is less than 50' and Expansion Index is less than or equal to 90 or Differential Fill Thickness is between 10 and 20' (see note 1). Category III: Max. Fill Thickness exceeds 50', or Expansion Index exceeds 90 but is less than 130, or Differential Fill Thickness exceeds 20' (see note 1). Notes: 1. Post tension (PT) foundations are required where maximum fill exceeds 50', or the ratio of the maximum fill thickness to the minimum fill thickness exceeds 3:1. Consideration should be given to using post tension foundations where the expansion index exceeds 90. Footing depth measured from lowest adjacent subgrade. Allowable soil bearing pressure is 2,000 PSF. Concrete for slabs and footings shall have a minimum compressive strength of 2,000 PSI (2,500 PSI for exterior flatwork), or adopted UBC min., at 28 days, using 5 sacks of cement. Maximum Slump shall be 5". Visqueen vapor barrier not required under garage slab. However, consideration should be given to future uses of the slab area, such as room conversion and/or storage of moisture-sensitive materials. Isolated footings shall be connected to foundations per soils engineer's recommendations (see report). Sand used for base under slabs shall be very low expansive, and have SE > 30. Additional exterior flatwork recommendations are presented in the text of this report. All slabs should be provided with weakened plane joints to control cracking. Joint spacing should be in accordance with correct industry standards and reviewed by the project structural engineer. 2. 3. 4. 6. 7. 8. 9. TABLE 2 PRELIMINARY POST TENSION SLAB FOUNDATION RECOMMENDATIONS Expansion Index Foundation Category Expansion Index l(PT) Very Low to Low (0-50) II (PT) Medium (51-90) lll(PT) High (>90) Perimeter footing embedment 12" 18" (w/premoistening) (24" (w/premoistening) Allowable bearing value 1200 psf* 1200 psf* 1200 psf* Modulus of subgrade reaction 100 pci/inch 75 pci/inch 75 pci/inch Coefficient of friction 0.35 0.35 0.35 Passive pressure 225 pcf 225 pcf 225 pcf Soil suction (Pf) 3.6 3.6 3.6 Depth to constant soil suction 5 feet 5 feet 5 feet Thornthwaite moisture -20.0 -20.0 -20.0 ©m edge 2.5 2.7 3.0 e^ center 5.0 5.5 5.5 Vm edge 0.35 0.5 0.75 Vm center 1.1 2.0 2.5 IVIinimum slab thickness 5 inches 5 inches 5 inches *lnternal bearing values for grade beams of the Post-tension slab may be designed per the criteria provided for conventional foundations. APPENDIX A REFERENCES I APPENDIX A REFERENCES Southern California Soil and Testing, Inc., 1990, Interim report of geotechnical Investigation, Calavera Heights, Village L-2, Hanwich Drive, Carlsbad, Californa, W.O. 9021054, dated May 4. , 1984, Summary of geotechnical investigation for Lake Calavera Hills, Villages E-1, E-2, H, L-2, L-3, Q, R, S, T, U and W-X, Carlsbad, California, W.O. 14112, Report No. 6., dated August 6. International Conference of Building Officials, 1997, Uniform Building Code. GeoSoils, Inc. APPENDIX B GENERAL EARTHWORK AND GRADING GUIDELINES GENERAL EARTHWORK AND GRADING GUIDELINES General These guidelines present general procedures and requirements for earthwork and grading as shown on the approved grading plans, including preparation of areas to filled, placement of fill, installation of subdrains and excavations. The recommendations contained in the geotechnical report are part of the earthwork and grading guidelines and would supersede the provisions contained hereafter in the case of conflict. Evaluations performed by the consultant during the course of grading may result in new recommendations which could supersede these guidelines or the recommendations contained in the geotechnical report. The contractor is responsible for the satisfactory completion of all earthwork in accordance with provisions of the project plans and specifications. The project soil engineer and engineering geologist (geotechnical consultant) or their representatives should provide observation and testing services, and geotechnical consultation during the duration of the project. EARTHWORK OBSERVATIONS AND TESTING Geotechnical Consultant Prior to the commencement of grading, a qualified geotechnical consultant (soil engineer and engineering geologist) should be employed for the purpose of observing earthwork procedures and testing the fills for conformance with the recommendations of the geotechnical report, the approved grading plans, and applicable grading codes and ordinances. The geotechnical consultant should provide testing and observation so that determination may be made that the work is being accomplished as specified. It is the responsibility of the contractor to assist the consultants and keep them apprised of anticipated work schedules and changes, so that they may schedule their personnel accordingly. All clean-outs, prepared ground to receive fill, key excavations, and subdrains should be observed and documented by the project engineering geologist and/or soil engineer prior to placing and fill. It is the contractors's responsibility to notify the engineering geologist and soil engineer when such areas are ready for observation. Laboratory and Field Tests Maximum dry density tests to determine the degree of compaction should be performed in accordance with American Standard Testing Materials test method ASTM designation D-1557-78. Random field compaction tests should be performed in accordance with test method ASTM designation D-1556-82, D-2937 or D-2922 and D-3017, at intervals of approximately 2 feet of fill height or every 100 cubic yards of fill placed. These criteria GeoSoils, Inc. would vary depending on the soil conditions and the size ofthe project. The location and frequency of testing would be at the discretion of the geotechnical consultant. Contractor's Responsibility All clearing, site preparation, and earthwork performed on the project should be conducted by the contractor, with observation by geotechnical consultants and staged approval by the governing agencies, as applicable. It is the contractor's responsibility to prepare the ground surface to receive the fill, to the satisfaction of the soil engineer, and to place, spread, moisture condition, mix and compact the fill in accordance with the recommendations ofthe soil engineer. The contractor should also remove all major non- earth material considered unsatisfactory by the soil engineer. It is the sole responsibility ofthe contractor to provide adequate equipment and methods to accomplish the earthwork in accordance with applicable grading guidelines, codes or agency ordinances, and approved grading plans. Sufficient watering apparatus and compaction equipment should be provided by the contractor with due consideration for the fill material, rate of placement, and climatic conditions. If, in the opinion of the geotechnical consultant, unsatisfactory conditions such as questionable weather, excessive oversized rock, or deleterious material, insufficient support equipment, etc., are resulting in a quality of work that is not acceptable, the consultant will inform the contractor, and the contractor is expected to rectify the conditions, and if necessary, stop work until conditions are satisfactory. During construction, the contractor shall properly grade all surfaces to maintain good drainage and prevent ponding of water. The contractor shall take remedial measures to control surface water and to prevent erosion of graded areas until such time as permanent drainage and erosion control measures have been installed. SITE PREPARATION All major vegetation, including brush, trees, thick grasses, organic debris, and other deleterious material should be removed and disposed of off-site. These removals must be concluded prior to placing fill. Existing fill, soil, alluvium, colluvium, or rock materials determined by the soil engineer or engineering geologist as being unsuitable in-place should be removed prior to fill placement. Depending upon the soil conditions, these materials may be reused as compacted fills. Any materials incorporated as part of the compacted fills should be approved by the soil engineer. Any underground structures such as cesspools, cisterns, mining shafts, tunnels, septic tanks, wells, pipelines, or other structures not located prior to grading are to be removed or treated in a manner recommended by the soil engineer. Soft, dry, spongy, highly fractured, or otherwise unsuitable ground extending to such a depth that surface processing cannot adequately improve the condition should be overexcavated down to Cypress Valley, LLC ' Appendix B File: e:\wp7\2700\2748a.ugr Page 2 GeoSoils, Inc. firm ground and approved by the soil engineer before compaction and filling operations continue. Overexcavated and processed soils which have been properly mixed and moisture conditioned should be re-compacted to the minimum relative compaction as specified in these guidelines. Existing ground which is determined to be satisfactory for support of the fills should be scarified to a minimum depth of 6 inches or as directed by the soil engineer. After the scarified ground is brought to optimum moisture content or greater and mixed, the materials should be compacted as specified herein. If the scarified zone is grater that 6 inches in depth, it may be necessary to remove the excess and place the material in lifts restricted to about 6 inches in compacted thickness. Existing ground which is not satisfactory to support compacted fill should be overexcavated as required in the geotechnical report or by the on-site soils engineer and/or engineering geologist. Scarification, disc harrowing, or other acceptable form of mixing should continue until the soils are broken down and free of large lumps or clods, until the working surface is reasonably uniform and free from ruts, hollow, hummocks, or other uneven features which would inhibit compaction as described previously. Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical), the ground should be stepped or benched. The lowest bench, which will act as a key, should be a minimum of 15 feet wide and should be at least 2 feet deep into firm material, and approved by the soil engineer and/or engineering geologist. In fill over cut slope conditions, the recommended minimum width of the lowest bench or key is also 15 feet with the key founded on firm material, as designated by the Geotechnical Consultant. As a general rule, unless specifically recommended otherwise by the Soil Engineer, the minimum width of fill keys should be approximately equal to Vz the height ofthe slope. Standard benching is generally 4 feet (minimum) vertically, exposing firm, acceptable material. Benching may be used to remove unsuitable materials, although it is understood that the vertical height ofthe bench may exceed 4 feet. Pre-stripping may be considered for unsuitable materials in excess of 4 feet in thickness. All areas to receive fill, including processed areas, removal areas, and the toe of fill benches should be observed and approved by the soil engineer and/or engineering geologist prior to placement of fill. Fills may then be properly placed and compacted until design grades (elevations) are attained. COMPACTED FILLS Any earth materials imported or excavated on the property may be utilized in the fill provided that each material has been determined to be suitable by the soil engineer. These materials should be free of roots, tree branches, other organic matter or other deleterious materials. All unsuitable materials should be removed from the fill as directed Cypress Valley, LLC Appendix B File: e:\wp7\2700\2748a.ugr Page 3 GeoSoils, Inc. by the soil engineer. Soils of poor gradation, undesirable expansion potential, or substandard strength characteristics may be designated by the consultant as unsuitable and may require blending with other soils to serve as a satisfactory fill material. Fill materials derived from benching operations should be dispersed throughout the fill area and blended with other bedrock derived material. Benching operations should not result in the benched material being placed only within a single equipment width away from the fill/bedrock contact. Oversized materials defined as rock or other irreducible materials with a maximum dimension greater than 12 inches should not be buried or placed in fills unless the location of materials and disposal methods are specifically approved by the soil engineer. Oversized material should be taken off-site or placed in accordance with recommendations ofthe soil engineer in areas designated as suitable for rock disposal. Oversized material should not be placed within 10 feet vertically of finish grade (elevation) or within 20 feet horizontally of slope faces. To facilitate future trenching, rock should not be placed within the range of foundation excavations, future utilities, or underground construction unless specifically approved by the soil engineer and/or the developers representative. If import material is required for grading, representative samples of the materials to be utilized as compacted fill should be analyzed in the laboratory by the soil engineer to determine its physical properties. If any material other than that previously tested is encountered during grading, an appropriate analysis of this material should be conducted by the soil engineer as soon as possible. Approved fill material should be placed in areas prepared to receive fill in near horizontal layers that when compacted should not exceed 6 inches in thickness. The soil engineer may approve thick lifts if testing indicates the grading procedures are such that adequate compaction is being achieved with lifts of greater thickness. Each layer should be spread evenly and blended to attain uniformity of material and moisture suitable for compaction. Fill layers at a moisture content less than optimum should be watered and mixed, and wet fill layers should be aerated by scarification or should be blended with drier material. Moisture condition, blending, and mixing of the fill layer should continue until the fill materials have a uniform moisture content at or above optimum moisture. After each layer has been evenly spread, moisture conditioned and mixed, it should be uniformly compacted to a minimum of 90 percent of maximum density as determined by ASTM test designation, D-1557-78, or as othenwise recommended by the soil engineer. Compaction equipment should be adequately sized and should be specifically designed for soil compaction or of proven reliability to efficiently achieve the specified degree of compaction. Cypress Valley, LLC Appendix B File: e:\wp7\2700\2748a.ugr Page 4 GeoSoils, Inc. membrane, with all laps sealed, should be provided at the mid-point ofthe sand layer. The slab subgrade should be free of loose and uncompacted material prior to placing concrete. 6. Concrete floor slabs (residence and garage) should be reinforced per Table 1. All slab reinforcement should be supported to ensure proper mid-slab height positioning during placement of the concrete. "Hooking" of reinforcement is not an acceptable method of positioning. 7. The moisture content of the subgrade soils should be equal to or greater than optimum moisture to a depth of 12 inches below the adjacent ground grade in the slab areas, and verified by this office within 72 hours ofthe vapor barrier placement. 8. Soils generated from footing excavations to be used onsite should be compacted to a minimum relative compaction 90 percent ofthe laboratory standard, whether it is to be placed inside the foundation perimeter or in the yard/right-of-way areas. This material must not alter positive drainage patterns that direct drainage away from the structural areas and toward the street. 9. As an alternative, an engineered post-tension foundation system may be used. Recommendations for post-tensioned slab design are presented in the following Section. Post-Tensioned Slab Foundation Systems 1. Post-tensioned (PT) slabs may be utilized for construction of typical one (1) and two (2) story residential structures onsite. The information and recommendations presented in this section are not meant to supersede design by a registered structural engineer or civil engineer familiar with post-tensioned slab design or corrosion engineering consultant. 2. From a soil expansion/shrinkage standpoint, a fairly common contributing factor to distress of structures using post-tensioned slabs is a significant fluctuation in the moisture content of soils underlying the perimeter of the slab, compared to the center, causing a "dishing" or "arching" of the slabs. To mitigate this possible phenomenon, a combination of soil presaturation (if necessary, or after the project has been dormant for a period of time) and construction of a perimeter "cut off' wall grade beam may be employed. 3. For very low to low (E.l.= 0 through 50) expansive soils, perimeter and mid span beams should be a minimum 12 inches deep below lowest adjacent pad grade. Perimeter beams should be a minimum of 18 inches deep for medium expansive and 24 inches deep for highly expansive soil conditions. The perimeter foundations Cypress Valley, LLC W.O. 2748-A-SC Calavera Hills, Village L-2 October 15,1999 File: e:\wp7\2700\2748a.ugr Page 5 GeoSoils, Inc. Where tests indicate that the density of any layer of fill, or portion thereof, is below the required relative compaction, or improper moisture is in evidence, the particular layer or portion shall be re-worked until the required density and/or moisture content has been attained. No additional fill shall be placed in an area until the last placed lift of fill has been tested and found to meet the density and moisture requirements, and is approved by the soil engineer. • Compaction of slopes should be accomplished by over-building a minimum of 3 feet horizontally, and subsequently trimming back to the design slope configuration. Testing shall be performed as the fill is elevated to evaluate compaction as the fill core is being developed. Special efforts may be necessary to attain the specified compaction in the fill slope zone. Final slope shaping should be performed by trimming and removing loose materials with appropriate equipment. A final determination of fill slope compaction should be based on obsen/ation and/or testing of the finished slope face. Where compacted fill slopes are designed steeper than 2:1 (horizontal to vertical), specific material types, a higher minimum relative compaction, and special grading procedures, may be recommended. If an alternative to over-building and cutting back the compacted fill slopes is selected, then special effort should be made to achieve the required compaction in the outer 10 feet of each lift of fill by undertaking the following: 1. An extra piece of equipment consisting of a heavy short shanked sheepsfoot should be used to roll (horizontal) parallel to the slopes continuously as fill is placed. The sheepsfoot roller should also be used to roll perpendicular to the slopes, and extend out over the slope to provide adequate compaction to the face of the slope. 2. Loose fill should not be spilled out over the face of the slope as each lift is compacted. Any loose fill spilled over a previously completed slope face should be trimmed off or be subject to re-rolling. 3. Field compaction tests will be made in the outer (horizontal) 2 to 8 feet of the slope at appropriate vertical intervals, subsequent to compaction operations. 4. After completion of the slope, the slope face should be shaped with a small tractor and then re-rolled with a sheepsfoot to achieve compaction to near the slope face. Subsequent to testing to verify compaction, the slopes should be grid-rolled to achieve compaction to the slope face. Final testing should be used to confirm compaction after grid rolling. 5. Where testing indicates less than adequate compaction, the contractor will be responsible to rip, water, mix and re-compact the slope material as necessary to achieve compaction. Additional testing should be performed to verify compaction. Cypress Valley, LLC Appendix B File: e:\wp7\2700\2748a.ugr Page 5 GeoSoils, Inc. 6. Erosion control and drainage devices should be designed by the project civil engineer in compliance with ordinances ofthe controlling governmental agencies, and/or in accordance with the recommendation ofthe soil engineer or engineering geologist. SUBDRAIN INSTALLATION Subdrains should be installed in approved ground in accordance with the approximate alignment and details indicated by the geotechnical consultant. Subdrain locations or materials should not be changed or modified without approval of the geotechnical consultant. The soil engineer and/or engineering geologist may recommend and direct changes in subdrain line, grade and drain material in the field, pending exposed conditions. The location of constructed subdrains should be recorded by the project civil engineer. EXCAVATIONS Excavations and cut slopes should be examined during grading by the engineering geologist. If directed by the engineering geologist, further excavations or overexcavation and re-filling of cut areas should be performed and/or remedial grading of cut slopes should be performed. When fill over cut slopes are to be graded, unless othenwise approved, the cut portion ofthe slope should be observed by the engineering geologist prior to placement of materials for construction of the fill portion of the slope. The engineering geologist should observe all cut slopes and should be notified by the contractor when cut slopes are started. If, during the course of grading, unforeseen adverse or potential adverse geologic conditions are encountered, the engineering geologist and soil engineer should investigate, evaluate and make recommendations to treat these problems. The need for cut slope buttressing or stabilizing should be based on in-grading evaluation by the engineering geologist, whether anticipated or not. Unless othenA/ise specified in soil and geological reports, no cut slopes should be excavated higher or steeper than that allowed by the ordinances of controlling governmental agencies. Additionally, short-term stability of temporary cut slopes is the contractors responsibility. Erosion control and drainage devices should be designed by the project civil engineer and should be constructed in compliance with the ordinances ofthe controlling governmental agencies, and/or in accordance with the recommendations of the soil engineer or engineering geologist. Cypress Valley, LLC Appendix B File: e:\wpA2700\2748a.ugr Page 6 GeoSoils, Inc. COMPLETION Observation, testing and consultation by the geotechnical consultant should be conducted during the grading operations in order to state an opinion that all cut and filled areas are graded in accordance with the approved project specifications. After completion of grading and after the soil engineer and engineering geologist have finished their observations of the work, final reports should be submitted subject to review by the controlling governmental agencies. No further excavation or filling should be undertaken without prior notification of the soil engineer and/or engineering geologist. All finished cut and fill slopes should be protected from erosion and/or be planted in accordance with the project specifications and/or as recommended by a landscape architect. Such protection and/or planning should be undertaken as soon as practical after completion of grading. JOB SAFETY General At GeoSoils, Inc. (GSI) getting the job done safely is of primary concern. The following is the company's safety considerations for use by all employees on multi-employer construction sites. On ground personnel are at highest risk of injury and possible fatality on grading and construction projects. GSI recognizes that construction activities will vary on each site and that site safety is the prime responsibility of the contractor; however, everyone must be safety conscious and responsible at all times. To achieve our goal of avoiding accidents, cooperation between the client, the contractor and GSI personnel must be maintained. In an effort to minimize risks associated with geotechnical testing and observation, the following precautions are to be implemented for the safety of field personnel on grading and construction projects: Safety Meetings: GSI field personnel are directed to attend contractors regularly scheduled and documented safety meetings. Safety Vests: Safety vests are provided for and are to be worn by GSI personnel at all times when they are working in the field. Safety Flags: Two safety flags are provided to GSI field technicians; one is to be affixed to the vehicle when on site, the other is to be placed atop the spoil pile on all test pits. Cypress Valley, LLC Appendix B File: e:\wp7\2700\2748a.ugr Page 7 GeoSoils, Inc. Flashing Lights: All vehicles stationary in the grading area shall use rotating or flashing amber beacon, or strobe lights, on the vehicle during all field testing. While operating a vehicle in the grading area, the emergency flasher on the vehicle shall be activated. In the event that the contractor's representative observes any of our personnel not following the above, we request that it be brought to the attention of our office. Test Pits Location. Orientation and Clearance The technician is responsible for selecting test pit locations. A primary concern should be the technicians's safety. Efforts will be made to coordinate locations with the grading contractors authorized representative, and to select locations following or behind the established traffic pattern, preferably outside of current traffic. The contractors authorized representative (dump man, operator, supervisor, grade checker, etc.) should direct excavation ofthe pit and safety during the test period. Of paramount concern should be the soil technicians safety and obtaining enough tests to represent the fill. Test pits should be excavated so that the spoil pile is placed away form oncoming traffic, whenever possible. The technician's vehicle is to be placed next to the test pit, opposite the spoil pile. This necessitates the fill be maintained in a driveable condition. Alternatively, the contractor may wish to park a piece of equipment in front of the test holes, particularly in small fill areas or those with limited access. A zone of non-encroachment should be established for all test pits. No grading equipment should enter this zone during the testing procedure. The zone should extend approximately 50 feet outward from the center of the test pit. This zone is established for safety and to avoid excessive ground vibration which typically decreased test results. When taking slope tests the technician should park the vehicle directly above or below the test location. If this is not possible, a prominent flag should be placed at the top of the slope. The contractor's representative should effectively keep all equipment at a safe operation distance (e.g. 50 feet) away from the slope during this testing. The technician is directed to withdraw from the active portion of the fill as soon as possible following testing. The technician's vehicle should be parked at the perimeter of the fill in a highly visible location, well away from the equipment traffic pattern. The contractor should inform our personnel of all changes to haul roads, cut and fill areas or other factors that may affect site access and site safety. In the event that the technicians safety is jeopardized or compromised as a result of the contractors failure to comply with any of the above, the technician is required, by company policy, to immediately withdraw and notify his/her supervisor. The grading contractors representative will eventually be contacted in an effort to effect a solution. However, in the Cypress Valley, LLC ' Appendix B File: e:\wp7\2700\2748a.ugr Page 8 GeoSoils, Inc. interim, no further testing will be performed until the situation is rectified. Any fill place can be considered unacceptable and subject to reprocessing, recompaction or removal. In the event that the soil technician does not comply with the above or other established safety guidelines, we request that the contractor brings this to his/her attention and notify this office. Effective communication and coordination between the contractors representative and the soils technician is strongly encouraged in order to implement the above safety plan. Trench and Vertical Excavation It is the contractor's responsibility to provide safe access into trenches where compaction testing is needed. Our personnel are directed not to enter any excavation or vertical cut which 1) is 5 feet or deeper unless shored or laid back, 2) displays any evidence of instability, has any loose rock or other debris which could fall into the trench, or 3) displays any other evidence of any unsafe conditions regardless of depth. All trench excavations or vertical cuts in excess of 5 feet deep, which any person enters, should be shored or laid back. Trench access should be provided in accordance with CAL-OSHA and/or state and local standards. Our personnel are directed not to enter any trench by being lowered or "riding down" on the equipment. If the contractor fails to provide safe access to trenches for compaction testing, our company policy requires that the soil technician withdraw and notify his/her supervisor. The contractors representative will eventually be contacted in an effort to effect a solution. All backfill not tested due to safety concerns or other reasons could be subject to reprocessing and/or removal. If GSI personnel become aware of anyone working beneath an unsafe trench wall or vertical excavation, we have a legal obligation to put the contractor and owner/developer on notice to immediately correct the situation. If corrective steps are not taken, GSI then has an obligation to notify CAL-OSHA and/or the proper authorities. Cypress Valley, LLC Appendix B File: e:\wp7\2700\2748a.ugr Page 9 GeoSoils, Inc. CANYON SUBDRAIN DETAIL TYPE A PROPOSED COMPACTED FILL NATURAL GROUND COLLUVIUM AND ALLUVIUM (REMOVE) y.^' W7/ TYPICAL BENCHING '^J'^^^ BEDROCK SEE ALTERNATIVES TYPE B \ \ \ PROPOSED COMPACTED FILL .yy NATURAL GROUND ^^^//\ ^\ ^ COLLUVIUM AND ALLUVIUM (REMOVE) wm TYPICAL BENCHING Y^^' BEDROCK SEE ALTERNATIVES NOTE: ALTERNATIVES. LOCATION AND EXTENT OF SUBDRAINS SHOULD BE DETERMINED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST DURING GRADING. PLATE EG-1 CANYON SUBDRAIN ALTERNATE DETAILS ALTERNATE 1: PERFORATED PIPE AND FILTER MATERIAL • MINIMUM A-1 12' MINIMUM FILTER MATERIAL MINIMUM VOLUME OF 9 FT.» '^^^.-.-.f^-T^^ /LINEAR FT. 6' i ABS OR PVC PIPE OR APPROVED yS.'. r.'.'.' ^ SUBSTITUTE WITH MINIMUM 8 lUl- i) PERFS LINEAR FT. IN BOTTOM HALF OF PIPl ASTM D2751. SDR 35 OR ASTM D1527. SCHD, 40 ASTM D3034. SDR 35 OR ASTM D1785, SCHD. 40 FOR CONTINUOUS RUN IN EXCESS OF56o FT. USE PIPE 6* MINIMUM B-1 FILTER MATERIAL SIEVE SIZE PERCENT PASSING 100 90-100 40-100 25-40. 18-33 5-15 .0-7 0-3 1 INCH 3/4 INCH 3/8 INCH NO. 4 NO. 8 NO, 30 'NO. 50 NO. 200 ALTERNATE 2: PERFORATED PIPE. GRAVEL AND.FILTER FABRIC 6-MINIMUM OVERLAP 6" MINIMUM COVER 4- MINIMUM BEDDING 6' MINIMUM OVERLAP A-2 4* MINIMUM BEDDING": GRAVEL MATERIAL 9 FP/LINEAR FT. PERFORATED PIPE: SEE ALTERNATE 1 GRAVEL: CLEAN 3/4 INCH ROCK OR APPROVED SUBSTITUTE FILTER FABRIC MIRAFI 140 OR APPROVED SUBSTITUTE PLATE EG-2 DETAIL FOR FILL SLOPE TOEING OUT ON PUT ALLUVIATED CANYON TOE OF SLOPE AS SHOWN ON GRADING PLAN ORIGINAL GROUND SURFACE TO BE RESTORED WITH COMPACTED FILL BACKCUTN^ARIES. FOR DEEP REMOVALS. ^ BACKCUT ^VKSHOULD BE MADE NO ^ STEEPER THAJ^:1 OR AS NECESSARY FOR SAFETY CONSIDERATIONS ^ / COMPACTED RLL ORIGINAL GROUND SURFACE r ANTICIPATED ALLUVIAL REMOVAL DEPTH PER SOIL ENGINEER. I PROVIDE A 1:1 MINIMUM PROJECTION FROM TOE OF SLOPE AS SHOWN ON GRADING PLAN TO THE RECOMMENDED REMOVAL DEPTH. SLOPE HEIGHT. SITE CONDITIONS AMO/CR LOCAL CONDITIONS COULD DICTATE FLATTER PROJECTKJNS. REMOVAL ADJACENT TO EXISTING FILL ADJOINING CANYON FILL COMPACTED RLL LIMITS LINE Qaf (EXISTING COMPACTED FILL) ,x TEMPORARY COMPACTED RLL "^^FOR DRAINAGE ONLY Qaf ^-^Qal ITO BE REMOVEDJ. ^c^^- y- TO BE REMOVED BEFORE PLACING ADDITIONAL COMPACTED RLL LEGEND Oaf ARTIFICIAL RLL Qal ALLUVIUM PLATE EG-3 TYPICAL STABILIZATION / BUTTRESS FILL DETAIL OUTLETS TO BE SPACED AT 100* MAXIMUM INTERVALS. AND SHALL EXTEND 12' BEYOND THE FACE OF SLOPE AT TIME OF. ROUGH GRADING COMPLETION. r- > m m o I BLANKET FILL IF RECOMMENDED BY THE SOIL ENGINEER P^^^ TYPICAL BENCHING DIAMETER NON-PERFORATED OUTLET PIPE AND BACKDRAIN (SEE ALTERNATIVES) BEDROCK 3'MINIMUM KEY DEPTH ^ W = 15'MINIMUM OR H/2 r- > H m m o I CJI TYPICAL STABILIZATION / BUTTRESS SUBDRAIN DETAIL 4- MINIMUM PIPE 2- MINIMUM I.- MINIMUM PIPE 2' MINIMUM FILTER MATERIAL: MINIMUM OF FIVE FIVLINEAR Fl OF PIPF OR FOUR FP/LINEAR Ft OF PIPE WHEN PLACED IN SQUARE CUT TRENCH, ALTERNATIVE IN LIEU OF RLTER MATERIAL: GRAVEL MAY BE EMCASED IN APPROVED FILTER FABRIC. FILTER FABRIC SHALL BE MIRAFI 140 OR EQUIVALENT. FILTER FABRIC SHALL BE LAPPED A MINIMUM OF 12" ON ALL JOINTS. MINIMUM 4- DIAMETER PIPE: ABS-ASTM D-2751. SDR 35 OR ASTM D-1527 SCHEDULE 40 PVC-ASTM D-3034. SpR 35 OR ASTM D-1785 SCHEDULE 40 WITH A CRUSHING STRENGTH OF 1.000 POUNDS MINIMUM. AND A MINIMUM OF 8 UNIFORMLY SPACED PERFORATIONS PER FOOT OF PIPE INSTALLED WITH PERFORATIONS OF BOTTOM OF PIPE. PROVIDE CAP AT UPSTREAM END OF PIPE. SLOPE AT 2% TO OUTLET PIPE, OUTLET PIPE TO BE CONNECTED TO SUBDRAIN PIPE WITH TEE OR ELBOW. NOTE: 1. TRENCH FOR OUTLET PIPES TO BE BACKFILLED WITH ON-SITE SOIL. 2. BACKDRAINS AND LATERAL DRAINS SHALL BE LOCATED AT ELEVATION OF EVERY BENCH DRAIN. FIRST DRAIN LOCATED AT ELEVATION JUST ABOVE LOWER LOT GRADE. ADDITIONAL DRAINS MAY BE REQUIRED AT THE DISCRETION OF THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST. FILTER MATERIAL SHALL BE OF THE FOLLOWING SPECIFICATION OR AN APPROVED EQUIVALENT: SIEVE SIZE PERCENT PASSINQ 1 INCH 10 0 3/4 INCH 90-100 3/8 INCH 40-100 NO. 4 25-40 NO. 8 18-33 NO. 30 5-15 NO. 50 0-7 NO. 200 0-3 GRAVEL SHALL BE OF THE FOLLOWING SPECIFICATION OR AN APPROVED EQUIVALENT: SIEVE SIZE PERCENT PASSING 1 1/2 INCH 100 NO. 4 50 NO. 200 8 SAND EQUIVALENT: MINIMUM OF 50 FILL OVER NATURAL DETAIL SIDEHILL FILL PROPOSED GRADE COMPACTED FILL "MAINTAIN MINIMUM 15* WIDTH TOE OF SLOPE AS SHOWN ON GRADING PLAN PROVIDE A 1:l MINIMUM PROJECTION FROM DESIGN TOE OF SLOPE TO TOE OF KEY AS SHOWN ON AS BUILT T) > m m o I cn NATURAL SLOPE TO BE RESTORED WITH COMPACTED FILL BACKCUT VARIES PW:^. MINIMUM BENCH WIDTH MAY VARY 15* MINIMUM KEY WIDTH 2'X 3*MINIMUM KEY DEPTH 2" MINIMUM IN BEDROCK OR APPROVED MATERIAL, |3'. MINIMUM NOTE: 1. WHERE THE NATURAL SLOPE APPROACHES OR EXCEEDS THE DESIGN SLOPE RATIO. SPECIAL RECOMMENDATIONS WOULD BE PROVIDED BY THE SOILS ENGINEER, 2. THE NEED FOR AND DISPOSITION OF DRAINS WOULD BE DETERMINED BY THE SOILS ENGINEER BASED UPON EXPOSED CONDITIONS. FILL OVER CUT DETAIL CUT/FjUi, CONTACT 1. AS SHOWN ON GRADING PLAN 2. AS SHOWN ON AS BUILT MAINTAIN MINIMUM 15* FILL SECTION FROM BACKCUT TO FACE OF FINISH SLOPE BENCH WIDTH MAY VARY '''A>^ BEDROCK OR APPROVED MATERIAL LOWEST BENCH WIDTH 15'MINIMUM OR H/2 Tl > m m o I NOTE: THE CUT PORTION OF THE SLOPE SHOULD BE EXCAVATED AND EVALUATED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST PRIOR TO CONSTRUCTING THE FILL PORTION. ID r- > H m m o I CO STABILIZATION FILL FOR UNSTABLE MATERIAL EXPOSED IN PORTION OF CUT SLOPE POSED FINISHED GRADE ^ UNWEATHERED BEDROCK OR APPROVED MATERIAL COMPACTED STABILIZATION FILL r MINIMUM TILTED BACK IF RECOMMENDED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST. THE REMAINING CUT PORTION OF THE SLOPE MAY REQUIRE REMOVAL AND REPLACEMENT WITH COMPACTED RLL. NOTE: 1. SUBDRAINS ARE NOT REQUIRED UNLESS SPECIFIED BY SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST, 2. -W- SHALL BE EQUIPMENT WIDTH 115*1 FOR SLOPE HEIGHTS LESS THAN 25 FEET. FOR SLOPES GREATER THAN 25 FEET "W SHALL BE DETERMINED BY THE PROJECT SOILS ENGINEER AND /OR ENGINEERING GEOLOGIST, AT NO TIME SHALL 'W BE LESS THAN H/2. DAYLIGHT CUT LOT DETAIL RECONSTRUCT COMPACTED RLL SLOPE AT 2:1 OR FLATTER (MAY INCREASE OR DECREASE PAD AREA). OVEREXCAVATE AND RECOMPACT REPLACEMENT RLL AVOID AND/OR CLEAN UP SPILLAGE OF MATERIALS ON THE NATURAL SLOPE NATURAL GRADE PROPOSED FINISH GRADE Ta* MINIMUM BLANKET FILL ^/ "^yy^^^ \^ BEDROCK OR APPROVED MATERIAL TYPICAL BENCHING ^GRADj^T,//. m m o I NOTE: 1. SUBDRAIN AND KEY WIDTH REQUIREMENTS WILL BE DETERMINED BASED ON EXPOSED SUBSURFACE CONDITIONS AND THICKNESS OF OVERBURDEN. 2. PAD OVER EXCAVATION AND RECOMPACTION SHOULD BE PERFORMED IF DETERMINED NECESSARY BY THE SOILS ENGINEER AND/OR THE ENGINEERING GEOLOGIST. TRANSITION LOT DETAIL CUT LOT {MATERIAL TYPE TRANSITION) NATURAL GRADE COMPACTED RLL OVEREXCAVATE AND RECOMPACT ^^//<<S^//<iS.'^^^^ 3* MINIMUM^ ^ UNWEATHERED BEDROCK OR APPROVED MATERIAL 17# TYPICAL BENCHING CUT-FILL LOT (DAYUGHT TRANSITION) PAD GRADE COMPACTED FILL NATURAL GRADE ~;^?»^>^ OVEREXCAVATE ANO RECOMPACT ^QV\>^^^>-^I//A\V^^^^^ 3- MINIMUM' ^ UNWEATHERED BEDROCK OR APPROVED MATERIAL TYPICAL BENCHING NOTE: •DEEPER OVEREXCAVATION MAY BE RECOMMENDED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST IN STEEP CUT-RLL TRANSITION AREAS. PLATE EG-11 OVERSIZE ROCK DISPOSAL VIEWS ARE DIAGRAMMATIC ONLY. ROCK SHOULD NOT TOUCH AND VOIDS SHOULD BE COMPLETELY FILLED IN. VIEW NORMAL TO SLOPE FACE PROPOSED FINISH GRADE OO 15' MINIMUM OO 5* MINIMUM (CI 10' MINIMUM (E) do OO OO 151MINIMUM |A) \>- H50 OD CO CO (Gt OO :K OR APPROVED MATERIAL VIEW PARALLEL TO SLOPE FACE PROPOSED RNISH GRADE 10' MINIMUM (E) 1^100* MAXIMUM IB)^ oooooc»ocjri3t»:j'-*jo CD ooc>=e=>s3=>o QOOOOCOOOOO 10'MINIMUM 3' MINIMUM o 10'MINIMUM (G) OOQCP (F) Is'MINIMUM (C) BEDROCK OR APPROVED MATERIAL NOTE: lA) (B) (C) (D) (E) ONE EQUIPMENT WIDTH OR A MINIMUM OF 15 FEET. HEIGHT AND WIDTH MAY VARY DEPENDING ON ROCK SIZE AND TYPE OF EQUIPMENT USED. LENGTH OF WINDROW SHALL BE NO GREATER THAN 100* MAXIMUM. IF APPROVED BY THE SOILS ENGINEER AND/OR ENGINEERNG GEOLOGIST^ WINDROWS MAY BE PLACED DIRECTLY ON COMPETENT MATERIALS OR BEDROCK PROVIDED ADEQUATE SPACE IS AVAILABLE FOR COMPACTION. ORIENTATION OF WINDROWS MAY VARY BUT SHALL BE AS RECOMMENDED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST. STAGGERING OF WINDROWS IS NOT NECESSARY UNLESS RECOMMENDED. CLEAR AREA FOR UTILITY TRENCHES., FOUNDATIONS AND SWIMMING POOLS. IF) VOIDS IN WINDROW SHALL BE RLLED BY FLOODING GRANULAR SOIL INTO PLACE. GRANULAR SOIL SHALL BE ANY SOIL WHICH HAS A UNIFIED SOIL CLASSIRCATION SYSTEM lUBC 29-1) DESIGNATION OF SM. SP. SW. GP. OR GW. ALL RLL OVER AND AROUND ROCK WINDROW SHALL 89 COMPACTED TO 90% RELATIVE COMPACTION. AFTER RLL BETWEEN WINDROWS IS PLACED AND COMPACTED WITH THE UFT OF RLL COVERING WINDROW, WINDROW SHALL BE PROOF ROLLED WITH A D-9 DOZER OR EQUIVALENT. OVERSIZED ROCK IS OEHNED AS LARGER THAN U*. AND LESS THAN 4 FEET IN SIZE. PLATE EG-12 (G) (H ROCK DISPOSAL PITS FILL LIFTS COMPACTED OVER ROCK AFTER EMBEDMENT GRANULAR MATERIAL COMPACTED FILL SEE OF EXCAVATION TO BE COMMENSURATE WITH ROCK SEE. NOTE: 1. LARGE ROCK IS DERNED AS ROCK LARGER THAN 4 FEET IN MAXIMUM SCE. 2. PIT IS EXCAVATED INTO COMPACTED RLL TO A DEPTH EQUAL TO 1/2 OF ROCK SEE. 3. GRANULAR SOIL SHOULD BE PUSHED INTO PIT AND DENSIFIED BY FLOODING. USE A SHEEPSFOOT AROUND ROCK TO AID IN COMPACTION. 4. A MINIMUM OF 4 FEET OF REGULAR COMPACTED RLL SHOULD OVERLIE EACH PIT. 5. PITS SHOULD BE SEPARATED BY AT LEAST 15 FEET HORCONTALLY. 6. PITS SHOULD NOT BE PLACED WITHIN 20 FEET OF ANY RLL SLOPE. 7. PITS SHOULD ONLY BE USED IN DEEP FILL AREAS. PLATE EG-13 SETTLEMENT PLATE AND RISER DETAIL 2'X 2'X 1/4- STEEL PLATE STANDARD 3/4" PIPE NIPPLE WELDED TO TOP OF PLATE. 3/4- X 5'GALVANIZED PIPE. STANDARD PIPE THREADS TOP AND BOTTOM. EXTENSIONS THREADED ON BOTH ENDS AND ADDED IN 5' INCREMENTS. 3 INCH SCHEDULE 40 PVC PIPE SLEEVE. ADO IN 5* INCREMENTS WITH GLUE JOINTS. FINAL GRADE MAINTAIN 5'CLEARANCE OF HEAVY EQUIPMENT. MECHANICALLY HAND COMPACT IN 2'VERTICAL -rV LIFTS OR ALTERNATIVE SUITABLE TO AND ACCEPTED BY THE SOILS ENGINEER. MECHANICALLY HAND COMPACT THE INITIAL 5* VERTICAL WITHIN A 5'RADIUS OF PLATE BASE. NOTE 1, 4. BOTTOM OF CLEANOUT PROVIDE A MINIMUM 1" BEDDING OF COMPACTED SAND LOCATIONS OF SETTLEMENT PLATES^s^^^^^^^ MARKED AND READILY VISIBLE (RED PLAGGEDl TO EQUIPMENT OPERAT^^^ CONTRACTOR SHOULD MAINTAIN CLEARA^^^^^ ^^^^ SHOULD BE'HANO COMI^JC^ PloTci's'pECIRCATlSN^ OR COMPACTED BY ALTERNATIVE APPROVED^|Y;H|J°JP^^^^^^ CONTRACTOR SHOULD MAINTAIN A 5'RADIUS lll'c^T.l S^irN':clLY°'ANfcOMPACT INITIAL 2'OF RLL PRIOR TO ESTABLISHING THE INITIAL READING. -riKir IN THE EVENT OF DAMAGE TO THE SETTLEMENT PLATE OR EXTENSION RESVLJING cpr^M FmifpMENT OPERATING WITHIN THE SPECIRED CLEARANCE AREA. CONTRACTOR SSULDTM^DU^EU NI);^^ BE RESPONSIBLE mo necTnoiKir TUP <;FTTLEMENT PLATES TO WORKING UKUtK. ^N AL^IRNATE DESIGN IJio METHOD OF INSTALLATION MAY BE PROVIDED AT THE DISCRETION OF THE SOILS ENGINEER. PLATE EG-U TYPICAL SURFACE SETTLEMENT MONUMENT RNISH GRADE 3*-6" 3/8- DIAMETER X 6* LENGTH CARRIAGE BOLT OR EQUIVALENT ^* DIAMETER X 3 1/2* LENGTH HOLE CONCRETE BACKFILL PLATE EG-15 TEST PIT SAFETY DIAGRAM SIDE VIEW ( NOT TO SCALE ) TOP VIEW 100 FEET 50 FEET iii u. a in 50 FEET APPROXIMATE CENTER OF TEST PIT vew:L£ a u. o tn FLAG ( NOT TO SCALE ) PLATE EG-16 OVERSIZE ROCK DISPOSAL VIEW NORMAL TO SLOPE FACE 20" MINIMUM CO J5'MINIMUM [Al^ ^Fs* MINIMUM (C) OO OO PROPOSED FINISH GRADE 10' MINIMUM (E) CO CO 15'MINIMUM (A) o-— OO CO OO (G) OO OO ooiFJ BEDROCK OR APPROVED MATERIAL VIEW PARALLEL TO SLOPE FACE PROPOSED FINISH GRADE FROM CA BEDROCK OR APPROVED MATERIAL NOTE: (A) ONE EQUIPMENT WIDTH OR A MINIMUM OF 15 FEET. HEIGHT AND WIDTH MAY VARY DEPENDING ON ROCK SEE AND TYPE OF EQUIPMENT LENGTH OF WINDROW SHALL BE NO GREATER THAN 100'MAXIMUM. IF APPROVED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST. WINDROWS MAY BE PLACED DIRECTLY ON COMPETENT MATERIAL OR BEDROCK PROVIDED ADEQUATE SPACE IS AVAILABLE FOR COMPACTION. ORIENTATION OF WINDROWS MAY VARY BUT SHOULD BE AS RECOMMENDED BY TfJk SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST. STAGGERING OF WINDROWS IS NOT NECESSARY UNLESS RECOMMENDED, itj CLEAR AREA FOR UTILITY TRENCHES. FOUNDATIONS AND SWIMMING POOLS. IF) ALL RLL OVER AND AROUND ROCK WINDROW SHALL BE COMPACTED TO 90% RELATIVE COMPACTION OR AS RECOMMENDED. ACTFR FM I RFTWEEN WINDROWS IS PLACED AND COMPACTED WITH THE LIFT OF FILL COVERING WINDROW. WINDROW SHOULD BE PROOF ROLLED WITH A Q-9 DOZER OR EQUIVALENT. VIEWS ARE DIAGRAMMATIC ONLY. ROCK SHOULD NOT TOUCH „ r.^,-, „ IND VOTDS SHSULD BE COMPLETELY RLL£D IN. PLATE RQ-I (A) (B) (C) (D IE (G) ROCK DISPOSAL PITS VIEWS ARE DIAGRAMMATIC ONLY. ROCK SHOULD NOT TOUCH AND VOIDS SHOULD BE COMPLETELY RLLED IN. RLL LIFTS COMPACTED OVER ROCK AFTER EMBEDMENT GRANULAR MATERIAL COMPACTED RLL SEE OF EXCAVATION TO BE COMMENSURATE WITH ROCK SIZE ROCK DISPOSAL LAYERS GRANULAR SOIL TO RLL VOIDS. DENSIRED BY FLOODING LAYER ONE ROCK HIGH \1 ^OMPACTED FILL PROPOSED RNISH GRADE 10'MINIMUM OR BELOW LOWEST UTILI PROFILE ALONG LAYER FRbWsSLOPE FACE "y"cLEAR ZONE 20" MINIMUM LAYER ONE ROCK HIGH PLATE RD-2