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HomeMy WebLinkAboutLot 28 Geotechnical InvestigationPETRA ' COSTA MESA• NEWPORT BEACH• SAN DIEGO •TEMECULA\Z ZagSU' ' January 20, 1998 J.N. 540-97 RICHMOND AMERICAN HOMES ' 104 W. Grande Avenue, Suite A Escondido, California 92025 ' Attention: Mr. John Mecklenburg Subject: Geotechnical Investigation, Omdahl Property, Lot 28 of Tract No. 3334, City of Temecula, Riverside County, California ' Petra Geotechnical, Inc. is pleased to submit herewith our geotechnical investigation report for the proposed residential development to be built in the City of Temecula, ' California. This work was performed in accordance with the scope of work outlined in our Proposal No. 1610-97 dated December 23, 1997. This report presents the results of our field investigation, laboratory testing and our engineering judgement, opinions, conclusions, and recommendations pertaining to geotechnical design aspects ' of the proposed development. ' It has been a pleasure to be of service to you on this project. Should you have any questions regarding the contents of this report, or should you require additional ' information, please do not hesitate to contact us. ' Respectfully submitted, PETRA GEOTECHNICAL, INC. Mark, Senior soc(ate Geologist LAB/MB/D W/keb Distribution: (4) Addressee PETRA GEOTECHNICAL, INC. 7620 Commerce Centre Drive, Suite 103 Temecula, CA 92590 Tel: (909) 699-6193 Fax: (909) 699-6197 JAN 071999 CITY OF TEMECULA ENGINEERING DEPARTMENT RICHMOND AMERICAN HOMES TR 3334/Omdahl Property 111.10 11I► Section January 20, 1998 J.N. 540-97 Page i Page INTRODUCTION..................................................1 Location and Site Description .............................. 1 INVESTIGATION AND LABORATORY TESTING ...................... 4 Literature Review ........................................ 4 Field Exploration ........................................ 4 Laboratory Testing ....................................... 5 ' Secondary Effects of Seismic Activity .................... 8 Seismic Design Considerations ......................... 9 ' CONCLUSIONS AND RECOMMENDATIONS ......................... 9 General................................................ 9 Earthwork.............................................10 ' General Earthwork and Grading Specifications .. 10 Clearing and Grubbing ......... ............ 10 Excavation Characteristics ............................ 11 1 Groundwater...................11 Ground Preparation - Fill Areas ........................ 11 Disposal of Oversize Rock ............................ 12 ' Fill Placement......................................12 Benching..........................................12 Processing of Cut Areas .............................. 13 ' Cut/Fill Transition Lots .............................. 13 Cut Slopes ......................................... 13 Stabilization Fill Backdrains .......................... 14 ' Fill Slopes ......................................... 14 Fill Above Cut and Cut to Fill Transition Slopes ........... 15 Landscaping For Cut and Fill Slopes and Surfrcial Erosion .. 15 ' Effect of Propose Grading on Adjacent Properties ............. 16 Shrinkage and Subsidence ..... .. .. 16 �2 U FINDINGS........................................................5 Regional Geologic Setting ................................. 5 Local Geology and Soil Conditions .......................... 6 ' Groundwater............................................6 Faulting ..7 Seismicity.............................................. 7 ' Secondary Effects of Seismic Activity .................... 8 Seismic Design Considerations ......................... 9 ' CONCLUSIONS AND RECOMMENDATIONS ......................... 9 General................................................ 9 Earthwork.............................................10 ' General Earthwork and Grading Specifications .. 10 Clearing and Grubbing ......... ............ 10 Excavation Characteristics ............................ 11 1 Groundwater...................11 Ground Preparation - Fill Areas ........................ 11 Disposal of Oversize Rock ............................ 12 ' Fill Placement......................................12 Benching..........................................12 Processing of Cut Areas .............................. 13 ' Cut/Fill Transition Lots .............................. 13 Cut Slopes ......................................... 13 Stabilization Fill Backdrains .......................... 14 ' Fill Slopes ......................................... 14 Fill Above Cut and Cut to Fill Transition Slopes ........... 15 Landscaping For Cut and Fill Slopes and Surfrcial Erosion .. 15 ' Effect of Propose Grading on Adjacent Properties ............. 16 Shrinkage and Subsidence ..... .. .. 16 �2 U RICHMOND AMERICAN HOMES January 20, 1998 TR 3334/Omdahl Property J.N. 540-97 Page ii TABLE OF CONTENTS (Continued) Geotechnical Inspections ................................. 17 Post Grading Considerations .............................. 17 Utility Trenches....................................17 Site Drainage......................................18 Foundation Recommendations ............................. 19 Allowable Bearing Values ............................ 19 Settlement.........................................19 Deepened Footings..................................20 Footing Observations ................................ 21 Expansive Soil Considerations ......................... 21 Retaining Wall Parameters ............................ 23 Crib Retaining Wall Parameters ........................ 24 Temporary Backcut Slopes for Retaining Walls ........... 24 Concrete Flatwork and Garden Walls ................... 25 Soluble Sulfate Analyses ............................. 25 GRADING PLAN REVIEW AND CONSTRUCTION SERVICES .......... 25 INVESTIGATION LIMITATIONS ................................... 26 Figure 1 - Site Location Map ' References Plate 1 - Geotechnical Map (in pocket) 'Appendices Appendix A - Logs of Borings and Trenches ' Appendix B - Laboratory Test Criteria/Laboratory Test Data Appendix C - Standard Grading Specifications GI I ' RICHMOND AMERICAN HOMES January 20, 1998 ' TR 3334/Omdahl Property J.N. 540-97 Page 1 ' GEOTECHNICAL INVESTIGATION OMDAHL PROPERTY, LOT 28 OF TRACT NO. 3334, CITY OF TEMECULA RIVERSIDE COUNTY, CALIFORNIA ' This report presents the results of Petra Geotechnical, hic.'s (Petra's) geotechnical investigation of the subject property. The purposes of this investigation were to ' determine the nature of surface and subsurface soil conditions, to evaluate their in- place characteristics, and to provide geotechnical recommendations with respect to site ' grading, and for design and construction of building foundations. This investigation also included a review of published and unpublished literature and geotechnical maps ' pertaining to active and potentially active faults that lie in proximity to the site and which may have an impact on the proposed construction. Location and Site Description The subject site, which is currently vacant, is located on the south side of Margarita Road between Avenida Cima Del Sol and Avenida Sonoma in the City of Temecula, ' California. The roughly rectangular -shaped property consists of gently rolling hills and an ephemeral drainage along the northern portion of the property. ' Elevations vary from approximately 1,110 feet above sea level within the northwest ' portion of the site to approximately 1,181 feet above sea level along the east -central portion of the site. Gradients on the site range from nearly level to 3:1 ' (horizontal: vertical [h:v]). Drainage is generally towards the southwest. ' No underground structures are known to be present within the site. Vegetation within the site consists of riparian vegetation within the stream channel and ' dry grasses throughout the rest of the site. A 1 1 1 1 1 1 RICHMOND AMERICAN HOMES TR 3334/Omdahl Property January 20, 1998 J.N. 540-97 Page 2 The site is bordered on the north by Margarita Road, the east by residential housing, the west by a single residence and to the south by a rough -graded multi -residential site. The general location of the site is shown on Figure 1. Pr_000ced Development/Grading The enclosed 40 -scale topographic map (Plate 1) does not show the proposed development. However, the developer has indicated that the proposed development will consist of 134 single-family residences with associated interior access roads and park site at the northeast corner of the property. Maximum proposed cuts and fill are approximately 30 and 20 feet, respectively. Maximum cut slope height will be approximately 30 feet at a gradient of 2:1 (h:v). Maximum fill slope height will be approximately 20 feet at a gradient of 2:1 (h:v). The site is currently vacant and no evidence was observed that structures have existed on the site in the recent past. Piles of artificial fill, concrete and yard waste were observed on the site in and adjacent to the drainage. The western boundary of the site is lined with telephone lines and eucalyptus trees. Numerous rodent burrows exist throughout the property. A concrete -lined drainage ditch runs southward along the eastern edge of the property. An area of artificial fill exists in the vicinity of our Test Pit -2. Both the drainage ditch and the artificial fill were constructed in conjunction with the adjacent housing tract. Two surficial slump features exist in the northeast comer of the property on a 2:1 (h:v) fill slope, which was also constructed in conjunction with the adjacent housing tract. ' RICHMOND AMERICAN HOMES January 20, 1998 ' TR 3334/Omdahl Property J.N. 540-97 Page 3 ' The purposes of this study were to: (1) obtain information on the subsurface conditions within the project area; (2) evaluate the data; and (3) provide conclusions and ' recommendations for design and construction of the proposed structures as influenced by the subsurface conditions. ' The scope of our investigation consisted of: ' • Review of available published and unpublished data concerning geologic and soil conditions within and adjacent to the site that could have an impact on the proposed development. This included review of data acquired by other engineering ' firms for adjacent properties (see References). • Geologic mapping of the site. • Excavation, logging and selective sampling of four borings to depths of up to 41.5 feet. Boring locations are shown on Plate 1, and descriptive logs are given in Appendix A. • Excavation, sampling and logging of eight test pits to acquire soil samples for ' laboratory testing, and to evaluate geologic structure and lithology. Test pit logs are given in Appendix A, and the locations of these pits are shown on Plate 1. ' • Laboratory testing and analysis of representative samples (bulk and undisturbed) obtained from the borings and test pits to determine their engineering properties. Laboratory test criteria and test results are presented in Appendix B. ' • Preparation of a geotechnical map (Plate 1). ' • Engineering and geologic analysis of the data with respect to the proposed development. ' • An evaluation of faulting and seismicity of the region as it pertains to the site. ' • Preparation of this report presenting our findings, conclusions and recommendations for the proposed development. RICHMOND AMERICAN HOMES TR 3334/Omdahl Property January 20, 1998 J.N. 540-97 Page 4 Various geotechnical reports and geologic studies in proximity to the site were reviewed and are listed in the references (attached). Subsurface exploration was performed on December 29 and December 31, 1997, and involved the drilling of four exploratory borings to depths of 41.5 feet and eight test pits to depths of 17 feet below the ground surface throughout the site. The borings were drilled using a truck -mounted, continuous -flight, hollow -stem auger. The test pits were excavated utilizing a rubber -tired backhoe. Prior to our subsurface investigation, an underground utilities clearance was obtained from Underground Service Alert of Southern California. Earth materials encountered during the subsurface investigation were classified and logged in accordance with the visual -manual procedures of the Unified Soil Classification System. The approximate locations of the borings and test pits are shown on Plate 1, and descriptive logs are presented in Appendix A. Associated with the subsurface exploration was the collection of bulk samples (disturbed) and relatively undisturbed samples of soil for laboratory testing. Bulk samples consisted of selected soil materials obtained at selected depth intervals from the exploratory borings and test pits. Undisturbed samples were obtained using a 3 - inch -outside diameter modified California split -spoon soil sampler lined with brass rings. In the borings, the soil sampler was driven mechanically with successive 30 - inch drops of a free -fall driven, 140 -pound hammer. In the test pits, the soil sampler was driven manually with successive 30 -inch drops of a free -fall driven, 140 -pound H 1 I I I 11 RICHMOND AMERICAN HOMES TR 3334/Omdahl Property January 20, 1998 J.N. 540-97 Page 5 hammer. The central portions of the driven core samples were placed in sealed containers and transported to our laboratory for testing. . 1 1 . I r 1 1 L Maximum dry density, expansion potential, soluble sulfate analysis, consolidation characteristics and shear strength of remolded and undisturbed samples were determined for selected disturbed (bulk) and undisturbed samples of soil and bedrock materials considered representative of those encountered. Moisture content and unit dry density were also determined for in-place soil and bedrock materials in representative strata. A brief description of laboratory test criteria is given in Appendix B and all test data are summarized on Plates B-1 through B-8. In-situ moisture content and dry unit weight are included in the Exploration Logs, Plates A-1 through A-17 (Appendix A). An evaluation of the test data is reflected throughout the Conclusions and Recommendations Section of this report. The site is located within the Peninsular Range Geomorphic Province of California. The Peninsular Ranges are characterized by steep, elongated, northwest -trending valleys. More specifically, the site is located on the southwest portion of the Perris Block which is bounded on the north by the San Gabriel and Cucamonga faults, on the east by the San Jacinto fault, on the west by the Elsinore trough and on the south by an undefined zone south of Temecula. The Perris Block is predominantly composed of crystalline granitic basement complex of Cretaceous age with Quaternary sediment accumulation in low-lying areas. The crystalline basement complex forms well- rounded hills of moderate relief. Sparse volcanic units of Tertiary age occur in the western portion of the Perris Block. I I 1 I RICHMOND AMERICAN HOMES January 20, 1998 TR 3334/Omdahl Property J.N. 540-97 Page 6 Gently rolling hills of moderate relief occupy the site. Quaternary colluvium overlies Quaternary Pauba Sandstone throughout the hillside portion of the site. Two small areas of artificial fill were identified, one in the east -central portion of the site and a 2:1 (h:v) fill slope located in the northeast comer of the property. Quaternary alluvium overlies Pauba Sandstone along the drainage near the northern edge of the site. Artificial Fill (map symbol Afu) -- The artificial fill consists of alternating layers of medium brown silty sand which is moist and medium dense; and orange, coarse- grained, poorly graded sand which is also moist and medium dense. The artificial fill extends from the ground surface to approximately 12 feet below ground surface in the east -central portion of the site. Quaternary Alluvium (map _symhol nal) --The Quaternary alluvium is a medium brown to yellow -tan silty sand. It is fine- to coarse-grained, micaceous with sparse pea gravel. The alluvium is damp to moist and loose to medium dense with minor to moderate porosity throughout. The Quaternary alluvium extends from the ground surface to approximately 14 to 25 feet below ground surface. • Qmatemary-CaU iu n symboLQsa -- The colluvium is a medium brown, silty to clayey sand. It is fine- to coarse-grained, moist and loose to medium dense. Secondary porosity and rootlets are common. The Quaternary colluvium extends from the ground surface to 3 to 12 feet below ground surface within the swales and ' approximately 1 to 2 feet on hill tops Sandstone was encountered in every trench and boring excavated at the site. This unit consists of orange, coarse-grained, poorly graded sand which is commonly micaceous and clayey; and yellow tan micaceous silt which is occasionally clayey. ' The poorly graded sand is moist and dense to very dense. The silt is moist and medium stiff to stiff. ' Seepage was encountered in Boring 3 at 25 feet below ground surface. Based on local well data and on our experience in the area, groundwater lies in excess of 50t feet below the ground surface. a I 1 RICHMOND AMERICAN HOMES January 20, 1998 TR 3334/Omdahl Property J.N. 540-97 Page 7 ' Flowing water was observed at the time of our investigation within the northern ' drainage on the site. ' The hgeologic structure of the entire southern California area is dominated mainly by ' northwest -trending faults associated with the San Andreas system. Faults such as the Newport -Inglewood, Whittier, Elsinore, San Jacinto and San Andreas are major faults ' in this system and all are known to be active. In addition, the San Andreas, Elsinore and San Jacinto faults are known to have ruptured the ground surface in historic times. ' Based on our review of published and unpublished geotechnical maps and literature ' pertaining to site and regional geology, the closest active fault to the site is the Elsinore fault zone located approximately 2 miles to the west. ' The most significant fault, with respect to anticipated ground motions at the site, is the Wildomar branch of the Elsinore fault zone, due to its close distance and large possible tmagnitude. ' No other active or potentially active faults project through or toward the site, and the site does not lie within an Alquist-Priolo Special Studies Zone. ' Seismicity The maximum credible earthquake for a particular fault is the largest magnitude event that can reasonably be postulated to occur based upon existing geologic and seismologic evidence independent of time. Most maximum credible earthquakes generally cannot be assigned a meaningful probability of occurrence, which is usually ' very low over the useful design life of most construction. • RICHMOND AMERICAN HOMES January 20, 1998 ' TR 3334/Omdahl Property J.N. 540-97 Page 8 Based on our study, the Elsinore fault zone appears capable of generating the most ' severe ground shaking at the site with a maximum credible magnitude of 7.5 and a maximum probable magnitude of 6.6 on the Richter scale. ' Estimated peak site ground acceleration from a magnitude 7.5 earthquake on the Wildomar fault, should an event occur opposite the site, is on the order of 0.505g (Joyner and Fumal 1985). In some cases, for design purposes, the repeatable ' acceleration can generally be used. This is considered to be equal to approximately two-thirds the peak acceleration, thus: 67% x 0.505g. = 0.338g. A . U The property will probably experience ground shaking from at least small to moderate size earthquakes during the life of the proposed structure. Furthermore, it should be ' recognized that the Southern California region is an area of moderate to high seismic risk and that it is not considered feasible to make structures totally resistant to seismic ' related hazards. The accelerations previously mentioned are presented for your consideration; however, the design acceleration should be determined by the structural ' consultant, and be reflective of the type of structure proposed. Design in accordance with the current Uniform Building Code (UBC) and the seismic design parameters of ' the Structural Engineers Association of California is expected to satisfactorily mitigate the effects of ground shaking. Secondary Effects of Seismic Activity ' Secondary effects of seismic activity normally considered as possible hazards to a site include several types of ground failure as well as induced flooding. Various general types of ground failures which might occur as a consequence of severe ground shaking ' of the site include landsliding, ground subsidence, ground lurching, shallow ground liquefaction. The type failure rupture, and probability of occurrence of each of ground ' depends on the severity of the earthquake, distance from faults, topography, subsoils, A . U RICHMOND AMERICAN HOMES TR 3334/Omdahl Property January 20, 1998 J.N. 540-97 Page 9 and groundwater conditions, in addition to other factors. All of the above secondary effects of seismic activity are considered unlikely at the site. Seismically induced flooding which might be considered a potential hazard to a site normally includes flooding due to a tsunamis (seismic sea wave), a seiche, or failure of a major reservoir or retention structure upstream of the site. Since the site is located nearly 25 miles inland from the nearest coastline of the Pacific Ocean at an elevation in excess of 1,110 feet above mean sea level, the potential for seismically induced flooding due to a tsunamis run-up is considered nonexistent. Since no enclosed bodies of water lie adjacent to the site, the potential for induced flooding at the site due to a seiche (i.e., a wave-like oscillation of the surface of water in an enclosed basin that may be initiated by a strong earthquake) is also considered nonexistent. For seismic design (UBC Section 1627.2), the site should be assigned to Seismic Zone 4 per UBC Figure 16-2 of the 1994 UBC and a seismic zone factor (Z) of 0.4 should be used per UBC Table 16-I. Based on site geology and subsurface soil characteristics (UBC Section 16273), soil profile SZ, as defined by UBC Table 16J, is representative of the site. A site coefficient (S) of 1.2 is considered appropriate for design of the structure. General From a soils engineering and engineering geologic point of view, the subject property is considered suited for the proposed construction provided the following conclusions I \y RICHMOND AMERICAN HOMES TR 3334/Omdahl Property January 20, 1998 J.N. 540-97 Page 10 and recommendations are incorporated into the design criteria and project specifications. IWIMI ,M, ' All earthwork and grading should be performed in accordance with all applicable requirements of the Grading and Excavation Code, and the Grading Manual of the ' County of Riverside, California, in addition to the provisions of the UBC, including Chapter 16 and Appendix A33. Grading should also be performed in accordance with ' applicable provisions of the attached Standard Grading Specifications (Appendix C) prepared by Petra, unless specifically revised or amended herein. Clearing and Grubbin L I 1 All trash, weeds, grasses, brush, shrubs, and trees in areas to be graded shall be stripped and hauled offsite. Trees to be removed should be grubbed out such that their stumps and major root systems are also removed and the organic materials hauled offsite. During site grading, laborers should clear from fills any roots, tree branches, and other deleterious materials missed during clearing and grubbing operations. The project soils engineer or his qualified representative should be notified at the appropriate times to provide inspection and testing services during clearing operations to verify compliance with the above recommendations. In addition, any buried structures or unusual or adverse soil conditions encountered that are not described or anticipated herein should be brought to the immediate attention of the geotechnical consultant. .�� U RICHMOND AMERICAN HOMES January 20, 1998 ' TR 3334/Omdahl Property J.N. 540-97 Page 11 IExcavation Characteristics ' Based on the results of our exploratory borings and test pits, residual soil materials and other surficial deposits (i.e., colluvium, alluvium and fill) will be readily excavatable ' with conventional earthmoving equipment. Most bedrock materials will be excavatable with moderate to heavy ripping. No impenetrable bedrock strata were encountered in the exploratory test pits and borings in site areas to be graded. However, local areas of well -cemented strata may ' be encountered during grading. These beds are expected to be rippable; however, ripping of these beds may generate oversize materials (in excess of 12 inches) that may require special handling and placement. ' Groundwater Groundwater may be temporarily perched in areas adjacent to the northern drainage ' at approximately the 25 -foot elevation during and shortly after periods of heavy rainfall in the vicinity of the site. Generally, groundwater is expected to be excess of ' 50 feet below ground surface in the vicinity of the site. tGround Preparation-- U1 Areas All existing low density and potentially collapsible soil materials, such as loose ' manmade fill, slopewash, colluvium, alluvium and highly weathered bedrock, will ' require removal to underlying dense bedrock or dense native soils from each area to fill. Dense defined receive compacted native soils are as undisturbed native materials ' with an in-place relative density of 85 percent or greater based on ASTM D1557-91. fill, bottom in Prior to placing structural exposed surfaces each removal area should ' be scarified to a depth of at least 6 inches, watered or dried as necessary to achieve then in-place to near optimum moisture conditions, and recompacted a minimum ' relative density of 90 percent. U RICHMOND AMERICAN HOMES January 20, 1998 TR 3334/Omdahl Property J.N. 540-97 Page 12 ' Based on (test pits), borings and laboratory testing, anticipated depths of removals are ' shown on the enclosed geotechnical map (Plate 1). However, actual depths and horizontal limits of removals will have to be determined during grading on the basis of in -grading inspections and testing performed by the project soils engineer and/or engineering geologist. Disposal of Oversize Roek ' A certain amount of oversize rock may be encountered during grading (rock greater than 12 inches in maximum dimension). Oversize rock may be disposed of onsite by ' placing the rock in the lower portions of the deeper fills, and in a manner to avoid nesting. The rock should be placed individually or in windrows, and then completely ' covered with finer -grained, onsite earth materials. The finer -grained materials should be thoroughly watered and rolled to ensure closure of all voids. A typical rock ' disposal detail is shown on Plate SG -2 (Appendix Q. ' Fi11 PlacQment All fill should be placed in 6- to 8 -inch -thick maximum lifts, watered or air dried as ' necessary to achieve near optimum moisture conditions, and then compacted in place to a minimum relative density of 90 percent. The laboratory maximum dry density and ' optimum moisture content for each change in soil type should be determined in accordance with Test Method ASTM D 1557-91. l em&iug ' Compacted fills placed against canyon walls and on natural slope surfaces inclining at 5:1 (h:v) or greater should be placed on a series of level benches excavated into competent bedrock or dense native soils. Typical benching details are shown on Plates SG -3, SG -4, SG -5, SG -7, and SG -8 (Appendix Q. RICHMOND AMERICAN HOMES TR 3334/Omdahl Property January 20, 1998 J.N. 540-97 Page 13 Where low density surficial deposits of topsoil, slopewash, existing fill and/or alluvium are not removed in their entirety in cut areas (building pads and driveways), these materials will require overexcavation and replacement as properly compacted To minimize the detrimental effects of differential settlement, cut/fill transitions should be eliminated from all building areas where the depth of fill placed within the "fill" portion exceeds proposed footing depths. This should be accomplished by overexcavating the 'but' portion and replacing the excavated materials as properly compacted fill. Recommended depths of overexcavation are given below: Depth of Fill Depth of'Overexcavation Up to 3 feet Equal depth 3 to 6 feet 3 feet Greater than 6 feet One-half the thickness of fill placed on the "Fill' portion (10 feet maximum) Horizontal limits of overexcavation should extend beyond perimeter building lines a distance equal to the depth of overexcavation, or to a minimum distance of 5 feet, whichever is greater. yM Most cut slopes throughout the development are expected to be grossly stable to the planned height of 30 feet and at the maximum planned inclination of 2:1 (h:v). However, in -grading inspection of individual cut slopes will be required by the project engineering geologist to confirm favorable geologic structure of the exposed bedrock. RICHMOND AMERICAN HOMES January 20, 1998 TR 3334/Omdahl Property J.N. 540-97 Page 14 Where highly fractured bedding, out -of -slope bedding, seepage or non-cemented sand strata are observed, the cut slopes in question may require stabilization by means of a compacted buttress fill or stabilization fill. Cut slopes excavated in Quaternary Pauba Sandstone exposing poorly cemented sands will require overexcavation and replacement with stabilization fills. Internal backdrains will be required in all stabilization fills. Typical construction details are shown on Plates SG -5 and SG -6 (Appendix Q. Locations of the backdrains installed in stabilization fills should be determined during grading based on local topography and the most feasible exit points for outlet pipe. Proposed fill slopes, including recommended stabilization fill slopes constructed with onsite soil and/or bedrock materials, will be grossly and surficially stable at the inclination of 2:1 (h:v). Other fill slopes should be constructed as recommended below. A fill key excavated a minimum depth of 2 feet into competent bedrock or dense native soil will be required at the base of all fill slopes. The width of the fill key should equal one-half the slope height, or 15 feet, whichever is greater. Typical fill key construction details are shown on Plates SG -3 and SG -7 (Appendix C). To obtain proper compaction to the face of fill slopes, low height fill slopes should be overfilled and backfilled during construction, and then trimmed back to the compacted inner core. Where this procedure is not practical for higher slopes, final surface compaction should be obtained by backrolling during construction to achieve proper RICHMOND AMERICAN HOMES January 20, 1998 TR 3334/Omdahl Property J.N. 540-97 Page 15 compaction to within 6 to 8 inches of the finish surface, followed by rolling with a cable -lowered sheepsfoot and grid roller. A basal 15 -foot -wide fill key excavated into competent bedrock will be required at the base of all fill slopes proposed on existing ground surfaces inclining at 5:1 (h:v) or greater. Typical details for construction of the basal fill key are shown on Plate SG -3 (Appendix Q. Fill _Abov C'ut and Cut to FiII Transition_SlQpss Where fill above cut slopes is proposed, a 15 feet wide key excavated into competent bedrock or dense native soil should be constructed at the contact. The bottom of the key should be tilted back into the slope at a minimum gradient of two percent. A typical section for construction of fill above cut slopes is shown on Plate SG -7, (Appendix C) The lower cut portion of the slope should be excavated to grade and inspected by the project engineering geologist prior to constructing the fill portion. Where cut to fill transition slopes are proposed, the fill portion should be placed on a series of benches excavated into competent natural ground or bedrock. The benches should be at least 8 to 10 feet wide constructed at vertical intervals of approximately 5 feet, and tilted back into the slope at a minimum gradient of two percent. Where cut to fill transition contacts vary from about vertical to a few degrees from vertical, benching of the fill portion into the cut portion, as recommended above, will be difficult and may create a potential slip surface due to inadequate benching. Therefore, overexcavation of the cut portion and reconstruction of the entire slope with compacted fill is recommended. Landscaping For Cut and Fill Slopes and urficiaLErosion To minimize surficial erosion, all graded cut and fill slopes should be landscaped with a deep rooted plant material requiring minimal cultivation and irrigation water in order U RICHMOND AMERICAN HOMES TR 3334/Omdahl Property January 20, 1998 J.N. 540-97 Page 16 to thrive. An irrigation system should be installed; however, overwatering and subsequent saturation of slope surfaces should be avoided. Moreover, the irrigation system should consist of very shallow or above grade piping to avoid the need for deep trenching within the slope surfaces. All graded slopes should be landscaped as soon as practical after the completion of rough grading (whenever water is available for irrigation). If permanent landscaping cannot be provided within a reasonable period of time, spray -on products designed to seal slope surfaces should be considered as a temporary measure to inhibit surficial erosion. As a further measure to inhibit surficial erosion, the tops of all cut and fill slopes should be protected from surface runoff by means of top -of -slope compacted earth berms and/or concrete interceptor drains which collect and divert surface runoff to adjacent streets or other appropriate disposal areas. Effect of Pro oce =rading_on Adjaceat-P[aperties Proposed grading on this site will have a minimal effect on adjacent properties. Volumetric changes in earth quantities will occur when excavated onsite soil and bedrock materials are replaced as properly compacted fill. Following is an estimate of shrinkage and bulking factors for the various geologic units present onsite. These estimates are based on in-place densities of the various materials and on the estimated average degree of relative compaction achieved during grading. Shrinkage • Fill .................................................... 5 t 10% • Alluvium ............................................... 5 t 10% • Colluvium .............................................. 5 t 15% • Bedrock (Pauba Formation) .................................. 0 to 5% U I 1 RICHMOND AMERICAN HOMES January 20, 1998 TR 3334/Omdahl Property J.N. 540-97 Page 17 1 Subsidence from scarification and recompaction of exposed bottom surfaces in ' removal areas will vary from negligible in bedrock areas to approximately 0. 15 foot in dense native soils. The above estimates of shrinkage and subsidence are intended as an aid for project planners in determining earthwork quantities. However, these estimates should be iused with some caution since they are not absolute values. Contingencies should be made for balancing earthwork quantities based on actual shrinkage and subsidence that ' will occur during grading. ' �eotechnicalInspection s ' An inspection of clearing operations, removal of unsuitable surficial materials, cut and fill slope construction, and general grading procedures should be performed by Petra. ' Fills should not be placed without prior approval from the geotechnical consultants. The project soils engineer or his qualified representative should be present onsite ' during all grading operations to verify proper placement and compaction of fill, as well as to verify compliance with the recommendations presented herein. Post Grading Considerations 'Utility Trenches_ ' All utility trench backfill within street rights-of-way, utility easements, under sidewalks, driveways and building floor slabs, and within or in proximity to slopes ' should be compacted to a minimum relative density of 90 percent. Where onsite soils are utilized as backfill, mechanical compaction will be required. Density testing, along ' with probing, should be performed by the project soils engineer, or his representative, to verify proper compaction. ?P I I 1 11 1 1 RICHMOND AMERICAN HOMES TR 3334/Omdahl Property January 20, 1998 J.N. 540-97 Page 18 For deep trenches with vertical walls, backfill should be placed in approximately I- to 2 -foot -thick maximum lifts, and then mechanically compacted with a hydra - hammer, pneumatic tampers, or similar equipment. For deep trenches with sloped walls, backfill materials should be placed in approximately 8- to 12 -inch -thick maximum lifts, and then compacted by rolling with a sheepsfoot tamper or similar equipment. As an alternate for shallow trenches where pipe may be damaged by mechanical compaction equipment, such as under building floor slabs, imported clean sand having a sand equivalent value of 30 or greater may be utilized and jetted or flooded into place. No specific relative compaction will be required; however, inspection, probing, and if deemed necessary, testing should be performed. To avoid point loads and subsequent distress to clay, cement or plastic pipe, imported sand bedding should be placed at least 1 foot above all pipe in areas where excavated trench materials contain significant cobbles. Sand bedding materials should be thoroughly jetted prior to placement of backfill. Where utility trenches are proposed parallel to any building footing (interior and/or exterior trenches), the bottom of the trench should not be located within a 1:1 (h:v) plane projected downward from the outside bottom edge of the adjacent footing. Positive drainage devices such as sloping sidewalks, graded swales, and/or area drains should be provided around each building to collect and direct all water away from the structures. Neither rain nor excess irrigation water should be allowed to collect or pond against building foundations. Roof gutters and downspouts may be required on the sides of buildings where yard drainage devices cannot be provided and/or where RICHMOND AMERICAN HOMES TR 3334/Omdahl Property January 20, 1998 J.N. 540-97 Page 19 roof drainage is directed onto adjacent slopes. All drainage should be directed to adjacent driveways, to adjacent streets or to storm drain facilities. An allowable bearing value of 1,500 pounds per square foot may be used for mat foundations at a minimum of 12 inches below the lowest adjacent finish grade, pad footings and continuous 12 -inch -wide footings founded at a minimum depth of 12 inches below the lowest adjacent final grade. This value may be increased by 20 percent for each additional foot of width and/or depth to a maximum value of 2,500 pounds per square foot. Recommended allowable beating values include both dead and live loads and may be increased by one-third for short -duration wind and seismic forces. Calculations of settlement have been made based on the results of consolidation tests, on the anticipated loading, and on the settlement characteristics of the in-situ soils. These calculations indicate that pad footings will settle less than 0.75 inch, and that continuous footings will settle less than 0.75 inch. ' Differential settlement is expected to be about half of the total settlement. It is anticipated that the majority of the settlement will occur during or shortly following ' the completion of construction as the loads are applied. ' The above settlement estimates are based on the assumption that the grading will be performed in accordance with the grading recommendations presented elsewhere in this report and that representatives of Petra will observe or test the soil conditions in the footing excavations. 2V RICHMOND AMERICAN HOMES January 20, 1998 TR 3334/Omdahl Property J.N. 540-97 Page 20 A coefficient of friction of 0.4 times dead load forces may be utilized at the contact between concrete and the supporting soils to resist lateral loads. In addition, a passive earth pressure increasing at a rate of 200 pounds per square foot per foot of depth, to a maximum value of 2000 pounds per square foot may be used for footings constructed on level ground. Where retaining wall footings are constructed on slopes or near the tops of descending slopes, a passive earth pressure of 150 pounds per square foot per foot of depth, to a maximum value of 1500 pounds per square foot should be used. These values may be combined without reduction for resisting lateral forces. An increase of one-third of the above values may be used for short-term wind or seismic forces. The above values are based on footings placed directly against native soils, bedrock, or previously compacted fill. In the case where footing sides are formed, all backfill against footings should be compacted to at least 90 percent of maximum density. The expansion potential of onsite soils should be confirmed subsequent to rough -grading operations on a lot -by -lot basis. Deepened Footings Where building or retaining wall footings are proposed near the tops of descending slopes or on inclining slope surfaces, these footings should be deepened such that a minimum horizontal distance of 5 feet exists between the outside bottom edge of the footing and the face of the adjacent slope. This horizontal clearance is for compacted fill slopes and cut slopes exposing competent bedrock or dense native soils. Where footings are proposed on natural slopes overlain with loose residual soils, footings should be deepened such that a minimum horizontal distance of 10 feet is maintained between the outside bottom edge of the footing and the face of the adjacent slope. RICHMOND AMERICAN HOMES TR 3334/Omdahl Property January 20, 1998 J.N. 540-97 Page 21 All building and retaining wall footing trenches excavated within the above areas should be observed by the project soils engineer to see that they have been excavated into competent bearing soils, and to a depth which provides the recommended horizontal clearances from the face of the adjacent slope. All foundation excavations should be observed by the project soils engineer prior to the placement of forms, reinforcement, or concrete. The excavations should be trimmed neat, level, and square. All loose, sloughed, or moisture softened soil should be removed prior to concrete placement. Excavated materials from footing excavations should not be placed in -slab -on -grade areas unless properly compacted and tested. Soils at the site exhibit a very low expansion potential as classified in accordance with UBC Table 18 -I -B. Standard footing depths of 12 inches for a one-story and 18 inches for a two-story structure may be utilized for most lots. However, additional slab thickness, footing sizes and reinforcement should be provided, as required, by the project architect or structural engineer. Very Low -Expansion-- The results of our laboratory tests indicate that the onsite soils and bedrock materials exhibit a very low expansion potential as classified in accordance with UBC Table 18 -I -B. For this condition, it is recommended that footings and floors be constructed and reinforced in accordance with the following minimum criteria. However, additional slab thickness, footing sizes and reinforcement should be provided as required by the project architect or structural engineer. - Standard depth footings may be used with respect to building code requirements for the planned construction (i.e., 12 inches deep for one-story construction and 18 inches deep for two-story construction). Interior ZA 1 I ' RICHMOND AMERICAN HOMES January 20, 1998 ' TR 3334/Omdahl Property J.N. 540-97 Page 22 ' continuous footings for two-story construction may be founded at a minimum depth of 12 inches below the lowest adjacent final grade. ' - All continuous footings should be reinforced with two No. 4 bars, one top and one bottom. ' - Interior isolated pad footings supporting raised floors should be a minimum of 24 inches square and founded at minimum depths of 12 and 18 inches below ' the lowest adjacent final grade for one- and two-story construction, respectively. The pad footings should be reinforced with No. 4 bars spaced 18 inches on center, both ways, near the bottom of the footings. ' Exterior isolated pad footings intended for support of roof overhangs, such as patio covers, should be a minimum of 24 inches square and founded at a minimum depth of 18 inches below the lowest adjacent final grade. The pad footings should be reinforced with No. 4 bars spaced 18 inches on center, both ways, near the bottom of the footings. Living area concrete floor slabs should be 4 inches thick and reinforced with 6 -inch by 6 -inch, No. 6 by No. 6 welded -wire mesh; or with No. 3 bars spaced 24 inches on center, both ways. All slab reinforcement should be supported on concrete chairs or brick to ensure the desired placement near mid -depth. ' - Living area concrete floors should be underlain with a moisture vapor barrier consisting of a polyvinyl chloride membrane such as 6 -mil visqueen or equivalent. At least 2 inches of clean sand should be placed over the ' membrane to promote uniform curing of the concrete. - Garage floor slabs should be 4 inches thick and reinforced in a similar manner as living area floor slabs. Garage floor slabs should also be poured separately from adjacent wall footings with a positive separation maintained with 3/8 - inch -minimum felt expansion joint materials and quartered with weakened ' plane joints. A 12 -inch -wide grade beam founded at the same depth as adjacent footings should be provided across garage entrances. The grade beam should ' be reinforced with two No. 4 bars, one top and one bottom. - Presaturation of the subgrade below slab areas will not be required. However, ' prior to placing concrete the subgrade should be thoroughly moistened to promote uniform curing of the concrete and mitigate the development of shrinkage cracks. -1 ' .7i� RICHMOND AMERICAN HOMES January 20, 1998 TR 3334/Omdahl Property J.N. 540-97 Page 23 An active lateral earth pressure equivalent to a fluid having a density of 35 pounds per cubic foot should be used for design of walls retaining a drained level backfill. Where the backfill slopes upward at 2:1 (h:v), the above value should be increased to 50 pounds per cubic foot. The above values are for onsite soils which exhibit Very Low to Low expansions and are placed behind the walls a minimum horizontal distance equal to one-half the wall height. All retaining walls should be designed to resist surcharge loadings imposed by other nearby walls or structures in addition to the above active earth pressures. This condition will be an important design consideration where multiple walls are proposed on manufactured slopes. Where retaining walls are restrained at the top (i.e., interior building walls), the above active earth pressures should be increased by 50 percent. For interior retaining walls beneath buildings to be constructed in bedrock, the above values do not apply where the bedding of the bedrock dips into the walls (i.e., ). Earth pressures for design of these walls should be increased to 55 and 85 pounds per cubic foot for cantilevered and restrained walls, respectively. All retaining walls should be provided with weep holes or with perforated pipe and gravel subdrains to prevent entrapment of water in the backfill. Perforated pipe should consist of 4 -inch -minimum diameter PVC Schedule 40 or ABS SDR -35. The pipe should be laid with the perforations down and embedded in 3 cubic feet per foot of 1.5 inches, or 0.75 inch open -graded gravel wrapped in filter fabric. Filter fabric may consist of Mirafi 140N or equal. The outside portions of building walls supporting backfill should also be coated with a suitable water -proofing material to inhibit infiltration of moisture through the walls. All retaining wall backfill should be placed in thin horizontal lifts, watered as necessary to achieve near optimum moisture conditions, and compacted in place to a 2r' RICHMOND AMERICAN HOMES TR 3334/Omdahl Property January 20, 1998 J.N. 540-97 Page 24 minimum relative density of 90 percent. Flooding or jetting of backfill materials should be avoided. The project soils engineer should verify proper compaction of all backfill. Crib retaining walls should be designed to resist the active earth pressures recommended for design of masonry walls with respect to slope inclination of retained earth and expansion characteristics of backfill materials. Individual crib wall cells should be filled with granular, free -draining soils exhibiting a Sand Equivalent value of 30 or greater. All backfill placed within individual cells should be compacted to a minimum relative density of 90 percent. A pipe and gravel subdrain should also be placed behind crib walls. Pipe and gravel materials should be the same as recommended for masonry retaining walls. In addition, backfill placed behind crib retaining walls should be placed and compacted as recommended for masonry retaining walls. To facilitate construction of retaining walls not proposed on manufactured slopes, the lower 5 feet of temporary slopes which are excavated in compacted fill or bedrock may be cut vertical. The upper portions which exceed a height of 5 feet should be maintained at a gradient of 1:1 (h:v) for bedrock and compacted fill. Temporary backcuts on manufactured slopes should be constructed at a gradient of 1:1 (h:v) or flatter for the full height of the temporary backcut. All temporary slopes should be inspected by the project soils engineer or engineering geologist for any evidence of potential instability. Depending on the results of these inspections, flatter slopes may be necessary. RICHMOND AMERICAN HOMES January 20, 1998 ' TR 3334/Omdahl Property J.N. 540-97 Page 25 ' Concrete flatwork such as sidewalks and patio slabs should be at least 3.5 inches thick and provided with expansion joints at minimum spacings of 6 feet, each way. ' Concrete driveways should be at least 5 inches thick and provided with expansion joints at minimum spacings of 10 feet, each way. Concrete flatwork placed on 1 expansive soils should also be reinforced with 6 -inch by 6 -inch, No. 6 by No. 6 (6x6 - W1.4 x W1.4) welded wire mesh. In addition, subgrade soils should be thoroughly moistened prior to placing concrete. Footings for free-standing garden walls and rigid structures should be designed and reinforced with consideration to the expansion potential of the foundation soils and in a similar manner as for building foundations. Positive separations in walls should also be provided at corners and at horizontal ' spacings of approximately 25 feet to permit relative movement. Soluble Sulfate Analyses Laboratory test data indicate site soils contain less than 0.10 percent water soluble ' sulfates. Therefore, according to Table 26-A-6 of the UBC, no special cement will be required for concrete to be placed in contact with onsite soils. GRADING PLAN REVIEW AND CONSTRUCTION SERVICES ' This report has been prepared for the exclusive use of Richmond American Homes to ' assist the Project Engineer and Architect in the design of the proposed development. It is recommended that Petra be engaged to review the final design drawings and ' specifications prior to construction. This is to verify that the recommendations contained in this report have been properly interpreted and are incorporated into the ' project specifications. If Petra is not accorded the opportunity to review these documents, we can take no responsibility for misinterpretation of our recommendations. F 4-A U RICHMOND AMERICAN HOMES TR 3334/Omdahl Property January 20, 1998 J.N. 540-97 Page 26 We recommend that Petra be retained to provide soil engineering services during construction of the excavation and foundation phases of the work. This is to observe compliance with the design, specifications or recommendations and to allow design changes in the event that subsurface conditions differ from those anticipated prior to start of construction. If the project plans change significantly (e.g, building loads or type of structures), we should be retained to review our original design recommendations and their applicability to the revised construction. If conditions are encountered during construction that appear to be different than those indicated in this report, this office should be notified immediately. Design and construction revisions may be required. This report is based on the project as described and the geotechnical data obtained from the field tests performed at the locations indicated on the plan. The materials encountered on the project site and utilized in our laboratory investigation are believed representative of the total area. However, soils can vary in characteristics between excavations, both laterally and vertically. The conclusions and opinions contained in this report are based on the results of the described geotechnical evaluations and represent our best professional judgement. The findings, conclusions, and opinions contained in this report are to be considered tentative only, and subject to confirmation by the undersigned during the construction process. Without this confirmation, this report is to be considered incomplete and Petra or the undersigned professionals assume no responsibility for its use. In addition, this report should be reviewed and updated after a period of one year of if the site ownership or project concept changes from that described herein. T� RICHMOND AMERICAN HOMES January 20, 1998 TR 3334/Omdahl Property J.N. 540-97 Page 27 This report has not been prepared for use by parties or projects other than those named or described above. It may not contain sufficient information for other parties or other purposes. The professional opinions contained herein have been derived in accordance with current standards of practice, and no warranty is expressed or implied. Respectfully submitted, PETRA GEOTECHNICAL, INC. Lisa Battiato Staff Geologist Senior As CEG 8 LAB/MB/DW / i087 \� ;I maek. --�� '•✓ , r'cD�Ps ! a — 3 - l2 ..n:_- � 00 ,�I'�S" - l � ��� LU (����� O• .moi � �° Di = 1 zoo IAO 0 �^.,'� �'� // •<. , .. � O ,zoo � ��.�, �-^�•. _� � moi— – l uoo •' 1 � �! Ute' uY "" u _ � arrc � - of rj 10 ,10 V� 7J I o ( \may— nyon VA 00 • � � F'/�� ✓ c�4� V – � _ � "� ter.. " ' SITE LOCATION MAP Ret: Portion of USGS 7.5 Minute Topographic Map Series r BACHELOR MTN. QUADRANGLE. 1953. (Photorevised 1973) MURRIETA QUADRANGLE. 1953. (Photorevised 1979) SCALE: 1 INCH = 2000 FEET ' � PETRA GEOTECHNICAL. INC. ' J.N. 540-97 Jan, 1998 FIGURE 1 31 I ' RICHMOND AMERICAN HOMES January 20, 1998 TR 3334/Omdahl Property J.N. 540-97 ' REFERENCES ' Blake, TX, 1994, "BQFAULT" - A Computer Program for the Deterministic Prediction of Peak Horizontal Acceleration from Digitalized California Faults. ' California GeoTek, Inc., 1989, Preliminary Geotechnical Investigation Parcel 28, Tract Map 3334, Rancho California Area, Riverside County, California, Project No. 752WRC-490, dated December 18, 1989. tCalifornia, State of, Department of Water Resources, 1971, Water Wells and Springs in the Western Part of the Upper Santa Margarita River Watershed, Riverside ' and San Diego Counties, California, Bulletin No. 91-20, August 1971. Campbell, K.W., and Bozorgnia, Y., 1994, "Near -Source Attenuation of Peak Horizontal Acceleration from Worldwide Accelograms Recorded from 1957 ' to 1993"; Proceedings, Fifth U.S. National Conference on Earthquake Engineering, Vol. III, Earthquake Engineering Institute, pp. 283-292. ' Jennings, C.W., 1994, Fault Activity Map of California and Adjacent Areas, Map No. 6, Scale 1:750,000'. Kennedy, Michael P., 1977, Recency and Character of Faulting along the Elsinore Fault Zone in Southern Riverside County, California, Special Report 131. State of California Special Studies Zones, 1980, Murrieta Quadrangle, Scale 1 inch equals 24,000 feet, dated January 1, 1980. ' United States Geological Survey, 1953a, Bachelor Mountain Quadrangle, 7.5 Minute Topographic Series, Photorevised 1973. ' , 1953b, Murrieta Quadrangle, 7.5 Minute Topographic Series, Photorevised 1979. [] APPENDIX A LOGS OF BORINGS AND TRENCHES PETRA GEOTECHNICAL, INC. J.N. 540-91 E X P L O R A T I O N L 0 G Project: PROPOSED RESIDENTIAL DEVELOPMENT Boring No. :B-1 Location:S. OF MARGARITA RD, TEMECULA Elevation: 1121 Job No.: 540-97 Client: RICHMOND AMERICAN Date: 12/31/97 Drill Method: Hollowstem Driving Weight: 140 lbs/30" Logged By: L. BATTIATO Depth (Feet) Lith logy Material Description W r Samptek Laboratory Tests lowMoisture PerContent Foot Ci) Dry Density (pcf) Other Lab Tests 5 10 15 Silty SAND (SM): medium brown, fine- to medium -grained moderate clay, moist @ 5.0 feet: Silty SAND (SM): tan to brown, slightly orange, fine- to coarse-grained, damp, granitic, micaceous, slight secondary porosity, dense @ 10.0 feet: Silty SAND (SM): tan to brown, slightly orange, fine- to coarse-grained, slight clay, micaceous, moist, slight secondary porosity, sparse pea gravel, dense 33/ 33/ 37 12/ 21/ 31 14/ 15/ 20 4.6 9.9 12.8 113.4 114.0 120.5 01 'ATE3?NARY RAI 15A SANDSTONE <Up-) @ 15.0 feet: Clayey SAND (SC): orangish/brown, fine- to coarse-grained, caliche nodules, very moist, pea gravel, large biotite flakes, secondary porosity, dessication surfaces, dense Continued Next Page PLATE A-1 Petra Geotechnical, Inc. E X P L O R A T I O N L 0 G Project: PROPOSED RESIDENTIAL DEVELOPMENT Boring No.:B-1 Location:S. OF MARGARITA RD, TEMECULA Elevation: 1121 Job No.: 540-97 Client: RICHMOND AMERICAN Date: 12/31/97 Drill Method: Hollowstem Driving Weight: 140 lbs/30" Logged By: L. BATTIATO W Samples I Laboratory Tests Per Foot C B ° j e k Moisture Content (Z) Dry Density (pcf) Other Lab Tests Depth (Feet) ith- log Material Description alows a r @ 20.0 feet: Poorly graded SAND (SW) with 26/ Gravel: orange, fine- to very coarse-grained, 36/ abundant pea and 1/4 -inch -diameter gravel, 50/ granitic, moderate clay, moist, very dense. 5" Gravel: granitic, semi -rounded 1.0- to 1.5 -inch diameter —25- 40/ 12.4 116.7 44/ @ 25.5 feet: SILT to Clayey SILT (ML -MH): yellow-brown, fine-grained, moist, micaceous, 50 moderate clay, very dense TOTAL DEPTH OF BORING = 26.5 FEET NO GROUNDWATER ENCOUNTERED BORING BACKFILLED 12/31/97 Petra Geotechnical, Inc. PLATE A-2 36 E X P L O R A T I O N L 0 G Project: PROPOSED RESIDENTIAL DEVELOPMENT Boring No.:B-2 Location:S. OF MARGARITA RD, TEMECULA Elevation: 1116 Job No.: 540-97 Client: RICHMOND AMERICAN Date: 12/31/97 Drill Method: Hollowstem Driving Weight: 140 lbs/30" Logged By: L. BATTIATO Depth (Feet)ology Lith- Material Description W a a r Samples I Laboratory Tests 3 lows Per Foot C r° e B k Moure Contistent (i) Dry Density (pcf) Other Lab Tests 5 _10— 15 m 'ATEwNARY A' i i nm In rna n Silty SAND (SM): medium brown, fine- to medium -grained, moderate clay, moist @ 5.0 feet: Silty SAND (SM): light, orangish brown, fine- to coarse-grained, slightly clayey, micaceous, moist, few root hairs, slight secondary porosity, massive, medium dense @ 10.0 feet: Silty SAND (SM): yellow brown, fine- to coarse-grained, moist, massive, micaceous, sparse pea gravel, medium dense 5/ 7/ 11 9/ 17/ 19 9/ 16/ 28 6.0 9.2 14.9 115.7 112.3 117.2 WEATwvoEn n"ATPANARV PAURA SANDSTONE (Qps) @ 15.0 feet: Clayey SAND (SC): orange/ own, fine- to coarse-grained, pea gravel, dessication surfaces, granitic, micaceous, slightly mottled, moist, medium dense Q iATEPNAov PA BA SANDSTONE (Ups) Continued Next Page Petra Geotechnical, Inc. PLATEA-3 3" E X P L O R A T I O N L 0 G Project: PROPOSED RESIDENTIAL DEVELOPMENT Boring No.:B-2 Location:S. OF MARGARITA RD, TEMECULA Elevation: 1116 Job No.: 540-97 Client: RICHMOND AMERICAN Date: 12/31/97 Drill Method: Hollowstem Driving Weight: 140 lbs/30" Logged By: L. BATTIATO Depth (Feet) ith- log Material Description W a7Pero aContent r Samples Laboratory Tests Moisture (2) Dry Density (Pct) Other Lab Tests 25 —30- 35 @ 20.0 feet: Poorly Graded SAND (SP): orange, fine- and coarse-grained, clayey, moderate amount of pea gravel, massive, moist, micaceous, very dense 24/ 28/ 50/ 5" 26/ 40/ 50/ 5" 34/ 50/ 61. 30/ 40/ 50/ 4.5" 10.5 10.5 8.4 4.6 115.9 109.8 107.1 109.8 _ _ - _ -W s _ ZOO _ - _ - @ 25.0 feet: Well -Graded SAND (SW): yellow -tan, fine- to coarse-grained, moist, massive, sparse pea gravel, micaceous, very dense @ 30.0 feet: Well -graded SAND (SW): yellow tan, fine- to coarse-grained, massive, micaceous, sparse pea gravel, moist, very dense @ 35.0 feet: Well -Graded SAND (SW): yellow tan, fine- to coarse-grained, granitic, sparse pea gravel, massive, very moist Continued Next Page PLATE A-4 Petra Geotechnical, Inc. ?A E X P L O R A T I O N L 0 G Project: PROPOSED RESIDENTIAL DEVELOPMENT Boring No. :B-2 Location:S. OF MARGARITA RD, TEMECULA Elevation: 1116 Job No.: 540-97 Client: RICHMOND AMERICAN Date: 12/31/97 Drill Method: Hollowstem Driving Weight: 140 lbs/30" Logged By: L. BATTIATO W Samples Laboratory Tests Per Foot C ° e B I k Moisture Content (Z) Dry Density (pcf) Other Lab Tests Depth (Feet) L ith- logy Material Description T31ows e r @ 40.0 feet: Clayey SAND (SC): yellow/tan, 30/ 13.3 120.5 fine- to coarse-grained, massive, micaceous, 35/ moist, dense 40 TOTAL DEPTH OF BORING = 41.5 FEET NO GROUNDWATER ENCOUNTERED BORING BACKFILLED 12/31/97 Petra Geotechnical, Inc. PLATEA-5 !N E X P L O R A T I O N L 0 G Project: PROPOSED RESIDENTIAL DEVELOPMENT Boring No.:B-3 Location:S. OF MARGARITA RD, TEMECULA Elevation: 1126 Job No.: 540-97 Client: RICHMOND AMERICAN Date: 12/31/97 Drill Method: Hollowstem Driving Weight: 140 lbs/30" Logged By: L. BATTIATO Depth (Feet) Lith- log Material Description W a e r Samplesl Laboratory Tests Blows Per Foot C r e B I k Moisture Content (7.) Dry Density (pcf) Other Lab Tests 5 10 15 QUATERNARY A' 11 NTI IM !On i 1 Silty SAND (SM): medium brown, fine- to medium -grained, moderate clay, moist @ 5.0 feet: Silty SAND (SM): medium brown, fine- to coarse-grained, slightly clayey, moist, abundant secondary porosity, medium dense 11/ 10/ 10 e/ 13/ 18 10/ 18/ 24 8.4 13.7 14.6 111.1 118.1 114.4 @ 10.0 feet: Clayey SAND (SC): medium brown, fine- to coarse-grained, moist, micaceous, abundant secondary porosity, dessication surfaces, medium dense @ 15.0 feet: Clayey to Silty SAND (SC/SM): orange/brown, fine- to coarse-grained, moist, root casts, slight secondary porosity, medium dense Continued Next Page Petra Geotechnical, Inc. PLATE A-6 E X P L O R A T I O N L 0 G Project: PROPOSED RESIDENTIAL DEVELOPMENT Boring No.:B-3 Location:S. OF MARGARITA RD, TEMECULA Elevation: 1126 Job No.: 540-97 Client: RICHMOND AMERICAN Date: 12/31/97 Drill Method: Hollowstem Driving Weight: 140 lbs/30" Logged By: L. BATTIATO Depth (Feet) Lith- logy Material Description W a a r Samples Laboratory Tests 3 lows Per Foot C B ° � e k Moisture Content (i) Dry Density (pcf) Other Lab Tests —25-0OIIATERNAR 30 @ 20.0 feet: Clayey SAND (SC): yellow to orange/brown, mottled, fine- to coarse-grained, moist, slightly layered, abundant secondary porosity, slight manganese staining, dessication surfaces, medium dense 7/ 13/ 26 17/ 30/ 50 16/ 25/ 36 10.3 13.1 16.7 112.3 120.8 114.2 PARRA SnuncTnNr @ 25.0 feet: Clayey SAND (SC): orange/brown, fine- to coarse-grained, micaceous, massive, wet, very dense @ 30.0 feet: Clayey SAND (SC): yellow/brown, fine- to coarse-grained (predominantly fine-grained), moist, massive, micaceous, manganese staining, dense TOTAL DEPTH OF BORING = 31.5 FEET SEEPAGE ENCOUNTERED AT 25.0 FEET BORING BACKFILLED 12/31/97 Petra Geotechnical, Inc. PLATE A-7 AP I L I I 1 E X P L O R A T I O N L 0 G Project: PROPOSED RESIDENTIAL DEVELOPMENT Boring No.:B-4 Location:S. OF MARGARITA RD, TEMECULA Elevation: 1117 Job No.: 540-97 Client: RICHMOND AMERICAN Date: 12/31/97 Drill Method: Hollowstem Driving Weight: 140 lbs/30" Logged By: L. BATTIATO DepthLith- (Feet)ology Material Description W a e r Samples Laboratory Tests Blows Per Foot C B � Y e k Moisture Content (Z) Dry Density (pcf) Other Lab Tests 5 10 15 (21 'A riCAV rni i i nm in Inco i i Silty SAND (SM): medium brown, fine- to medium -grained, moderate clay, moist @ 5.0 feet: Silty SAND (SM): yellowish brown, fine- to coarse-grained, slightly clayey, moist, rootlets, abundant secondary porosity, loose @ 10.0 feet: Silty SAND (SM): yellow tan, fine- to coarse-grained (predominantly medium -grained), slightly clayey, massive, micaceous, secondary porosity, moist, medium dense @ 15.0 feet: Silty SAND (SM): yellow tan, fine- to coarse-grained (predominantly medium -grained), moist, slight horizontal layering, slight secondary porosity, medium dense 6/ 7/ 7 B/ 10/ 17 8/ 12/ 18 7.5 7,9 11.0 108.3 115.6 111.4 Continued Next Page Petra Geotechnical, Inc. PLATE A-6 A\ E X P L O R A T I O N L 0 G Project: PROPOSED RESIDENTIAL DEVELOPMENT Boring No.:B-4 Location:S. OF MARGARITA RD, TEMECULA Elevation: 1117 Job No.: 540-97 Client: RICHMOND AMERICAN Date: 12/31/97 Drill Method: Hollowstem Driving Weight: 140 lbs/30" Logged By: L. BATTIATO Depth (Feet) Lith- log Material Description W aBlow a r Samplesl Laboratory Tests s Per Foot C B ° e k Moisture Content (i) Dry Density (pcf) Other Lab Tests 25 41 30 35 @ 20.0 feet: Clayey SAND (SC): orange brown, fine- to coarse-grained, massive, moist, abundant secondary porosity, slight horizontal layering, medium dense 10/ 15/ 18 9/ 13/ 17 30/ 50/ 6" 35/ 54 7.6 9.7 9.6 6.9 112.9 115.4 110.3 108.0 5IIC1i5i'"A V RA1'BA SANDSTONE (Qpsl Clayey to Silty SAND (SC/SM): orange/brown, fine- to coarse-grained, massive, contains 1/4 -inch -diameter gravel, moist, slight secondary porosity, medium dense @ 30.0 feet: Poorly Graded SAND (SP): orange, fine- to coarse-grained (predominantly coarse-grained), slightly clayey, massive, moist, very dense @ 35.0 feet: Poorly Graded SAND (SP): orange, fine- and coarse-grained, massive, micaceous, slightly clayey, moist, very dense TOTAL DEPTH OF BORING = 36.0 FEET NO GROUNDWATER ENCOUNTERED BORING BACKFILLED 12/31/97 Petra Geotechnical, Inc. PLATE A-9 A7- M. M m m = m = m m = =M! m = m ► LOGGED BY: L Battiato DATE: 12/29197 ELEVATION:. 1150m¢ a �� EQUIPMENT:, Ru her tired Baclooe LOCATION: South of Margarita Road Temecula Ja m N =^ a d cn V :3F^ ~ N `u Bc 00 m °w' w+ w n Z GEOLOGIC DESCRIPTION aiz m 0V g o ATTTUDES D G) 0-5': Quaternary Colluvium (Qeol): Silty SAND: medium brown, fine- to coarse-grained, Bulk TP I aV- 2' SM massive, moderately indurated, moist, medium dense with rootlets and crotovina p_Irq , 7/12" O no, overt' ( 5-8': Quaternary Pauba Sandstone (Qps): Clayey SAND: yellow -tan, tine- and coarse- p_I (a 5 8/12- Sc 52 104.5 grained, granitic, massive, moderately indurated, moist, medium dense i Bulk TP - Z 7' 0 D TOTAL DEPTH: 8 FEET rP-1 I5/12 10.4 112.3 NO GROUND WATER ENCOUNTERED TEST PIT BACKFILLED AND WHEEL ROLLED n m• ~7 0 0 i GRAPHIC LOG SCALE: 1"=5, SURFACE SLOPE: 23' TREND: 0 X11 pwr iw r ;.. I .r a1>M, I SOOT WEST WALL 0 m M. � m= m== mm m m m m m m m y LOGGED By: L. Battiato DATE: 12/29/97 ELEVATION:. 1175 IL W EQUIPMENT: Rubber Tired Backhoe LOCATION: South of Margarita Road Temecula J W IL LL N = « d to U ~2e 1" y`u ? oSample,IL �g az 3 O W� p_ ui `a p w n GEOLOGIC ATTITUDES GEOLOGIC DESCRIPTION tnz m — - - p D 0 0-8' Artificial Fill (At): Silty SAND: medium brown, tine- to coarse-grained, slightly uIk TP- 2' 7.4 114.8 4 M clayey, layered with Poorly Graded SAND: orange, coarse-grained, slightly clayey, roots -24R2 2411^_- 0 within the top 2 feet, moist, dense lk TSM 8-10' QuaternaryColluvium(Qcol): Silty SAND: medium brown, fine- to medium -2 [4'K 16/h' 7.5 116.5 grained, with raNlets and moderate amount of pinhole porosity, damp to moist, medium ndense 2 A 8 8t12- 5.1 107.5 0) D 10-12' Quaternary Colluvium (Qcol): Clayey SAND: brown, tine- to coarse-grained, blocky horizontal layering, rootlets & casts, moderate amount of pinhole porosity, moist, SC Z medium dense 12-14': Quaternary Pauba Sandstone: (Qps): Poorly Graded SAND: orange, coarse- SP grained, slightly clayey, massive, well indurated, moist, dense m TOTA LDEPTH: 14 FEET 0 NO GROUND WATER ENCOUNTERED TEST PIT BACKFILLED AND WHEEL ROLLED n i GRAPHIC LOG SCALE:1"= SURFACE SLOPE: level TREND: N40W o 0_.: N — D ru r 1 m NORT IEAST WALL C M M M M M LOGGED BY: L. Battiato DATE: 12/2997 ELEVATION:. 1166 ~^ EQUIPMENT:.Rubbern ai redBacoe LOCATION: South ofMargantaRoad, Temecula -JulLL = «JU)'M' M a LU AT TTUDES GEOLOGIC DESCRIPTION tnZ mQ oP-3 3'20/12" 5.6 115.3 4 0-2': Quaternary Colluvium (Qcol): Silty SAND: medium brown, tine- to medium- SM R grained, with rootlets and moderate amount of pinhole porosity, damp to moist, medium dense i 2-8': Quaternary Colluvium (Qcol): Silty SAND: brown, fine- to coarse-grained, with SM Z 6 6 Y Y Y, small anuxmt of pinhole porosity, damp to small amount of ]ea gravel, slightly clayey, n1 n moist, medium dense. 8-10': Quaternary Pauba Sandstone: (Qps): Poorly Graded SAND: orange, coarse- SP grained, slightly clayey, massive, well indurated, moist, dense TOTAL DEPTH: 10 FEET M M NO GROUND WATER ENCOUNTERED 0 TEST PIT BACKFILLED AND WHEEL ROLLED n TY GRAPHIC LOG SCALE: 1"=5' SURFACE SLOPE: level TREND: N65W n 111 P r y N D m NOR EAST WALL M 0 LOGGED BY: L. Battiato DATE: 12/29/97 ELEVATION:1133w LL Uj ¢ (yA,f► EQUIPMENT: Rubber Tired Backhoe LOCATION: South of Margarita Road. Temecula _j W (L In y t m d N acUJ _ y NZ 3 d G Ui u o a LOGIC GEOLOGIC DESCRIPTION ATTOITUDES ro (" D 0-2': Quaternary Colluvium (Qa,l): Silty SAND: medium brown, fine- to coarse- SM ip 'M grained, slightly clayey, organic odor, abundant rootlets, moist, loose to medium dense M 0 O Bulk TP- @ 3'-4'0 , 2-3': Quaternary Colluvium (Qcol): Clayey SAND: orange-brown, fine- to coarse- � SC M grained with pea gravel, blocky, clamp, medium (tense Z3-7': Quaternary Pauba Sandstone (weathered) (Qps): Clayey SAND to CLAY: orange- n brown, fine-to medium-grained, very blocky, with rootlets and abundant caliche stringers, P-4 ® loll!" SC/CL 23.4 89.1 ` 7 D damp to moist, dense Bulk TP- 7' 7-12': Quaternary Pauba Sandstone (Qps): Clayey SAND to Silty SAND: yellow-hen, n fine- and coarse-grained, some pea gravel, blocky horizontal layering, moderately00 SC/SM 1.indurated, moist, dense 0 TOTAL DEPTH: 12 FEET -I NO GROUND W ATER ENCOUNTERED M TEST PIT BACKFILLED AND WHEEL ROLLED n Z GRAPHIC LOG SCALE: 1"=5' SURFACE SLOPE: 15 TREND: N8E n .10 J— UPs' W m AST WALL 0 yy�LOGGED BY: L.Battiato DATE: 12129197 ELEVATION:1140 wx LL Cc > EQUIPMENT:. Then Baclmo>a LOCATION: Roarth n1 Mar�3rita Rnnd Tamwruta d m N ~ to U F' to „- a W.to G ui Z 4 ov GEOLOGIC AT TUDES GEOLOGIC DESCRIPTION tarsi m � u' D o0-3': Quaternary Colluvium (Qcol): Silty SAND: medium brown, tine -to coarse- SM toM grained, with moderate amount of pea gravel, abundant pinhole porosity and rootlets, organic odor, moist, loose to medium dense M 3-7': Quaternary Colluvium (Qcol): Silty SAND: orange -brown, tine- to coarse- SM Zgrained, slightly clayey, with sparse pea gravel, blocky horizontal layering, rootlets, moderate amount of pinhole porosity and caliche nodules, moist, dense r A 7-15': Quaternary Pauba Sandstone (Qps): Poorly Graded SAND: orange -brown, SP _ predominantly coarse-grained, with sparse granitic cobbles to 5 inches in diameter, utk TP -5 Z the upper 5 feet is clayey and slightly blocky, below 12 feet the soil becomes massive 0000 . and clay content reduces, moist, dense 0 171 TOTAL DEPTH: 15 FEET NO GROUND WATER ENCOUNTERED A TEST PIT BACKFILLED AND WHEEL ROLLED 0 TY GRAPHIC LOG SCALE: 1"= ' SURFACE SLOPE: 9 TREND: N80W \I ,•fTt f S . . �: M • - :_ QUI.:::.::; O L7 0.:. I _ D r 1 D A m OUTH WALL yy� LOGGED BY: L.Battiato DATE: 12129/97 ELEVATION:.1160w¢ LL Lu ¢ > EQUIPMENT:. rTir Backhoe LOCATION: South of Margarita Road. Temecula 3 W w ti H K 2 O rn p Z GEOLOGIC ATTITUDES GEOLOGIC DESCRIPTION <M U)Z ro c� � 0 pv -- t" A D o 'a 0-2.5' Quaternary Colhrvium (Qcol): Silty SAND: medium brown, fine -to coarse- SM 4 grained, rootlets, abundant pinhole porosity, moist, loose to medium dense 2.54': Quaternary Colluvium (Qcol): Clayey SAND: orange -brown, tine- to coarse- Sc = grained, blocky, with pea gravel, a moderate amount of pinhole porosity, caliche n(xlules Z and rootlets, dan(p to moist, medium dense C_ n y 4-14': Quaternary Pauba Sandstone (Qps): Poorly Graded SAND: orange -brown, SP predominantly coarse-grained, slightly clayey, massive, moist, dense o m n TOTAL DEPTH: 14 FEET NO GROUND WATER ENCOUNTERED m TEST PIT BACKFILLED AND WHEEL ROLLED 0 M n i GRAPHIC LOG SCALE: 1"=5' SURFACE SLOPE: 23' TREND: N55W S • 14. G, m NOR EAST WALL LOGGED BY: L. Battiato DATE: 12/29497 ELEVATION:.1122 w¢ LL_ M >. ��d► EQUIPMENT:. LOCATION: South of Maroarita Road Temecula d m F m IL 0Ci Qj O p= to ca O� w a GEOLOGIC ATTITUDES GEOLOGIC DESCRIPTION rnz m p p tr p0-2.5': Quaternary Colluvium (Qcol): Silty SAND: medium brown, fine-to coarse- SM eD M grained, rootlets, abundant pinhole porosity, very moist, loose to medium dense Wp; TP- L1 al 46 2.5.4.5': Quaternary Colluvium (Qcol): Silty SAND; orange-brown, fine- to coarse- i7 grained, massive with caliche nodules and roots, damp to moist, dense SM x Z 4.5-8': Quaternary Colluvium (Qcol): Silty SAND; orange-brown, fine- to coarse-grained, n slightly clayey, massive with caliche nodules and rootlets, very moist, medium dense SM � D 8-15': Quaternary Colluvium (Qcol): Silty SAND: medium brown, predominantly coarse- SM z grained, clayey, moderate amount of pinhole porosity, rootlets and caliche nodules, moist, (D n medium dense SM/SC 15-17': Quaternary Pauba Sandstone (Qps): Silty SAND to Clayey SAND: yellow-tan, fine- to coarse-grained blocky, a moderate amount of pinhole porosity, moist, medium dense M O TOTAL DEPTH: 17 FEET NO GROUNDWATER ENCOUNTERED TEST PIT BACKFILLED AND WHEEL ROLLED GRAPHIC LOG SCALE: = SURFACE SLOPE: 7 TREND: N54W imp rtv4 co r -4 �1 D 1 D m — SOUT EST WALL -04 y�/r1► LOGGED By: L. Battiato DATE: 12/29/97 ELEVATION:.7132 LL M >. r— EQUIPMENT:.RU Tired Backhoe LOCATION: South of Maraarita Road Temecula w ¢ -t W a m = « 3 1-0 � U p ~ ^ N 22 to u Z Raj <� O p` O w a GEOLOGIC ATTITUDES GEOLOGIC DESCRIPTION MZ m -- p — D o 0-2': Quaternary Colluvium (Qcol): Silty SAND: medium brown, fine- to coarse-grained, SM 10.8 112.3 4 M massive, moderately indurated, very moist, medium dense with rootlets and organic odic P-8 Gd 3 28/1' - 2-4.5': Quaternary Colluvium (Qcol): Silty to Clayey SAND: yellow-brown, fine- to II A medium -grained, well indurated, blocky, with rootlets and abundant caliche stringers, Z damp, dense Z C_ n 4.5-6': Quaternary Pauba Sandstone (Qps): Silty SAND: yellow-brown, fine- to medium- D grained, micaceous, well indurated, caliche nodules, damp to moist, dense P_8 Q 18112SM 14.8 110.9 �Z 6-8': Quaternary Pauba Sandstone (Qps): SILT: yellow-brown, well indurated, blocky 0011. 0 horizontal layering, micaceous, manganese staining ML 8-10': Quaternary Pauba Sandstone (Qps): Clayey to Silty SAND: yellow-brown, fine- SC/SM to coarse-grained, with pea gravel, well indurated, moist, dense 0 TOTAL DEPTH: 10 FEET NO GROUND WATER ENCOUNTERED TEST PIT BACKFILLED AND WHEEL ROLLED - i GRAPHIC LOG SCALE: 1"=5' SURFACE SLOPE: 10' TREND: N65W n �Ii I S - - --_-- ao � D v m SOUTH EST WALL -04 APPENDIX B LABORATORY TEST CRITERIA LABORATORY TEST DATA PETRA GEOTECHNICAL, INC. J.N. 540-91 5\ IConsolidation ' Consolidation tests were performed in general accordance with ASTM Test Method D2435-80. Axial loads were applied in several increments to a laterally restrained 1 -inch -high sample. Loads were applied in a geometric progression by doubling the previous load, and the resulting deformations were recorded at selected time intervals. ' The test samples were inundated at a surcharge loading approximately equal to the existing or proposed total overburden pressures in order to evaluate the effects of a sudden increase in moisture content (hydroconsolidation potential). Results of these tests are graphically presented on Plates B-1 through B-4. ' B -Value ' R -value tests were performed on selected samples of soil and bedrock materials anticipated to be the most prevalent at grade at the completion of grading. The purpose of these tests were to provide preliminary data with respect to design of structural pavement sections. The R -value tests were performed by _ California, in accordance with California Test Method No. 301. Their test data are appended to this report. L� f1 I LI ' PETRA GEOTECHNICAL, INC. J.N. 540-91 1 6Z z 0 E A O z z 0 U Z U U C 0.. SAMPLE LOCATION MATERIAL DESCRIPTION INITIAL INUNDATED DENSITY Oxfl M0[. nm M SATURATION M LOAD (ksfl • B-1@20.0 Sand W/ Clay (SW -SC) 124.5 8.0 61 2.80 0.18 0.35 0.7 1.4 2.8 5.6 11.2 22.4 44.8 J.N. 540-97 PETRA GEOTECHNICAL, INC. VERTICAL STRESS - kips per square foot CONSOLIDATION TEST RESULTS 5 January, 1998 PLATE B-1 z 0 F ca 0 z z U U z z m U a m a SAMPLE LOCATION MATERIAL. DESCRIPIION INTDAL INUNDATED DENSITY (per I MOISTURE M SATURATION M LOAD (ksf) 0 B-3 @ 25.0 Silty Sand (SM) 120.8 13.1 90 2.80 0.18 0.35 0.7 1.4 2.8 5.6 11.2 22.4 44.8 VERTICAL STRESS - kips per square foot J.N. 540-97 CONSOLIDATION TEST RESULTS PETRA GEOTECHNICAL, INC. 5A January, 1998 PLATE B-2 li SAMPLE LOCATION MATERIAL DESCRIPTION iN1TIAL INUNDATED DENSITY MOISTURE SATURATION LOAD • B-4 @ 30.0 Sand W/ Silt (SW -SM) 110.3 9.8 50 3.50 0.18 0.35 0.7 1.4 2.8 5.6 11.2 22.4 44.8 VERTICAL STRESS - kips per square foot J.N. 540-97 January, 1998 CONSOLIDATION TEST RESULTS PETRA GEOTECHNICAL, INC. PLATE B-3 z 0 F A O z 0 z W U a SAMPLE LOCATION MATERIAL. DESCRHMON INITIAL INUNDATED DENSITY MOISTURE SATURATION LOAD • TP -2 @ 8.0 Silty Sand (SM) 107.5 5.1 24 0.80 0.18 0.35 0.7 1.4 2.8 5.6 11.2 22.4 44.8 VERTICAL STRESS - kips per square foot J.N. 540-97 January, 1998 CONSOLIDATION TEST RESULTS PETRA GEOTECHNICAL, INC. I PLATE B-4 z 0 a 0 z 0 u z U rL m a SAMPLE LOCATION MATERIAL DESCRIPTION INITIAL INUNDATED DEN MOISTURESATU �R%A�TION LOAD 0 B-4 @ 20.0 112.9 7.6 42 2.80 n-19 035 0.7 1.4 2.8 5.6 11.2 22.4 44.8 J.N. 540-97 PETRA GEOTECHNICAL, INC. VERTICAL STRESS - kips per square foot CONSOLIDATION TEST RESULTS '51 January,1998 PLATE B-5 SAMPLE LOCATION MATERIAL DESCRIPTION INITIAL INUNDATED DEQ MO�$ISIURE SATURATION LOAD • B-4 @ 25.0 115.4 9.7 57 2.80 0.18 0.35 0.7 1.4 2.8 5.6 11.2 22.4 44.8 J.N. 540-97 PETRA GEOTECHNICAL, INC. VERTICAL STRESS - kips per square foot CONSOLIDATION TEST RESULTS 6t> January, 1998 PLATE B-6 NORMAL STRESS - pounds per square foot SAMPLE LOCATION DESCRIPTION FRICTION ANGLE COHESION (PSF) • TP -1 @ 5.0 Sand W1 Silt (SW -SM) 43 30 NOTES: Undisturbed Test Samples - All Samples Were Inundated Prior to J.N. 540-97 PETRA GEOTECHNICAL, INC. DIRECT SHEAR TEST DATA UNDISTURBED TEST SAMPLES January,1998 PLATE B-7 T.ABORATORY MAXIMUM DRY DENSITY' Boring Depth Expansion Potential' Optimum Maximum Number 17 I: (ft.) Soil Type Moisture (%a) Dry Density ( cf) TP -7 I general I Silty SAND 10 127.0 EXPANSION INDEX TEST DATA Soil Type Expansion Index Expansion Potential' Silty SAND 17.0 Very Low Clayey SAND 18.0 Very Low SOLUBLE SULFATES° Soil a Sulfate Content (%) Clayey SAND 0.003 (1) PER TEST METHOD ASTM D 1557-91 (2) PER UNIFORM BUILDING CODE STANDARD TEST 18-2 (3) PER UBC TABLE 18 -I -B (4) PER CALIFORNIA TEST METHOD NO. 417 PLATE B-8 PETRA GEOTECHNICAL, INC. J.N. 540-91 (PO APPENDIX C STANDARD GRADING SPECIFICATIONS PETRA GEOTECHNICAL, INC. J.N. 540-91 60� 11 ' STANDARD GRADING SPECIFICATIONS These specifications present the usual and minimum requirements for ' grading operations performed under the control of Petra Geotechnical, Inc. No deviation from these specifications will be allowed, except where specifically superseded in the preliminary geology and soils report, or in other written communication signed by the Soils Engineer and Engineering ' Geologist. ' I. GENERAL A. The Soils Engineer and Engineering Geologist are the Owner's or ' Builder's representative on the project. For the purpose of these specifications, supervision by the Soils Engineer includes that inspection performed by any person or persons employed by, and ' responsible to, the licensed Civil Engineer signing the soils report. B. All clearing, site preparation, or earthwork performed on the project shall be conducted by the Contractor under the supervision of the Soils Engineer. C. It is the Contractor's responsibility to prepare the ground surface to receive the fills to the satisfaction of the Soils Engineer and to place, spread, mix, water, and compact the fill in accordance with the specifications of the Soils Engineer. The Contractor shall also remove all material considered unsatisfactory by the Soils Engineer. D. It is also the Contractor's responsibility to have suitable and sufficient compaction equipment on the job site to handle the amount of fill being placed. If necessary, excavation equipment will be shut down to permit completion of compaction. Sufficient watering apparatus will also be provided by the Contractor, with due consideration for the fill material, rate of placement, and time of year. ' Page 1 - STANDARD GRADING SPECIFICATIONS E. A final report shall be issued by the Soils Engineer and Engineering Geologist attesting to the Contractor's conformance with these specifications. ' II. SITE PREPARATION ' A. All vegetation and deleterious material such as rubbish shall be disposed of offsite. This removal shall be concluded prior to placing fill. 1 I 1 I 1 B. Soil, alluvium, or bedrock materials determined by the Soils Engineer as being unsuitable for placement in compacted fills shall be removed and wasted from the site. Any material incorporated as a part of a compacted fill must be approved by the Soils Engineer. C. After the ground surface to receive fill has been cleared, it shall be scarified, disced, or bladed by the Contractor until it is uniform and free from ruts, hollows, hummocks, or other uneven features which may prevent uniform compaction. The scarified ground surface shall then be brought to optimum moisture, mixed as required, and compacted as specified. If the scarified zone is greater than 12 inches in depth, the excess shall be removed and placed in lifts restricted to 6 inches. Prior to placing fill, the ground surface to receive fill shall be inspected, tested, and approved by the Soils Engineer. D. Any underground structures such as cesspools, cisterns, mining shafts, tunnels, septic tanks, wells, pipe lines, or others are to be removed or treated in a manner prescribed by the Soils Engineer. E. In order to provide uniform bearing conditions in cut/fill transition lots and where cut lots are partially in soil, colluvium, or unweathered bedrock materials, the bedrock portion of the lot extending a mini- mum of 3 feet outside of building lines shall be overexcavated a min- imum of 3 feet and replaced with compacted fill. (Typical details are given on Plate SG -1.) - Page 2 - (;✓ ' STANDARD GRADING SPECIFICATIONS ' III. COMPACTED FILLS ' A. Any material imported or excavated on the property may be utilized in the fill, provided each material has been determined to be t suitable by the Soils Engineer. Roots, tree branches, and other matter missed during clearing shall be removed from the fill as directed by the Soils Engineer. ' B. Rock fragments less than 12 inches in diameter may be utilized in the fill provided: ' 1. They are not placed in concentrated pockets. ' 2. There is a sufficient percentage of fine grained material to surround the rocks. ' 3. The distribution of rocks is supervised by the Soils Engineer. C. Rocks greater than 12 inches in diameter shall be taken offsite or placed in accordance with the recommendations of the Soils Engi- neer in areas designated as suitable for rock disposal. (Typical details for Rock Disposal are given in Plates SG -2 and SG -10.) D. Material that is spongy, subject to decay, or otherwise considered unsuitable shall not be used in the compacted fill. E. Representative samples of materials to be utilized as compacted fill ' shall be analyzed by the laboratory of the Soils Engineer to deter- mine their physical properties. If any material other than that previously tested is encountered during grading, the appropriate analysis of this material shall be conducted by the Soils Engineer as soon as possible. ' F. Material used in the compacting process shall be evenly spread, watered, processed, and compacted in thin lifts not to exceed 6 inches in thickness to obtain a uniformly dense layer. The fill shall be placed and compacted on a horizontal plane, unless otherwise approved by the Soils Engineer. - Page 3 - 0 STANDARD GRADING SPECIFICATIONS G. If the moisture content or relative density varies from that required by the Soils Engineer, the Contractor shall rework the fill until it is approved by the Soils Engineer. H. Each layer shall be compacted to 90 percent of the maximum density in compliance with the testing method specified by the controlling governmental agency. (In general, ASTM D 1557-91, will be used.) If compaction to a lesser percentage is authorized by the control- ling governmental agency because of a specific land use or expan- sive soils condition, the area to received fill compacted to less than 90 percent shall either be delineated on the grading plan or appro- priate reference made to the area in the soils report. I. All fills shall be keyed and benched through all topsoil, colluvium, alluvium or creep material, into sound bedrock or firm material where the slope receiving fill exceeds a ratio of 5 horizontal to 1 vertical, in accordance with the recommendations of the Soils Engi- neer. J. The key for side hill fills shall be a minimum of 15 feet within ' bedrock or firm materials, unless otherwise specified in the soils report. (See detail on Plate SG -3.) ' K Subdrainage devices shall be constructed in compliance with the ordinances of the controlling governmental agency, or with the recommendations of the Soils Engineer or Engineering Geologist. (Typical Canyon Subdrain details are given in Plate SG -4.) ' L The contractor will be required to obtain a minimum relative com- paction of 90 percent out to the finish slope face of fill slopes, buttresses, and stabilization fills. This may be achieved by either ' overbuilding the slope and cutting back to the compacted core, or by direct compaction of the slope face with suitable equipment, or by any other procedure which produces the required compaction. M. All fill slopes should be planted or protected from erosion by other methods specified in the soils report. ' Page 4 - �J I 1 STANDARD GRADING SPECIFICATIONS 1 N. Fill -over -cut slopes shall be properly keyed through topsoil, colluvium or creep material into rock or firm materials, and the 1 transition shall be stripped of all soils prior to placing fill. (See detail on Plate SG -7.) 1 IV. CUT SLOPES 1 A. The Engineering Geologist shall inspect all cut slopes at vertical intervals not exceeding 10 feet. 1 B. If any conditions not anticipated in the preliminary report such as perched water, seepage, lenticular or confined strata of a poten- tially adverse nature, unfavorably inclined bedding, joints or fault 1 planes are encountered during grading, these conditions shall be analyzed by the Engineering Geologist and Soils Engineer, and rec- ommendations shall be made to treat these problems. (Typical 1 details for stabilization of a portion of a cut slope are given in Plates SG -5 and SG -8.) 1 C. Cut slopes that face in the same direction as the prevailing drain- age shall be protected from slope wash by a non -erodible intercep- tor swale placed at the top of the slope. D. Unless otherwise specified in the soils and geological report, no cut t slopes shall be excavated higher or steeper than that allowed by the ordinances of controlling governmental agencies. 1 E. Drainage terraces shall be constructed in compliance with the ordinances of controlling governmental agencies, or with the rec- ommendations of the Soils Engineer or Engineering Geologist. 1 V. GRADING CONTROL 1 A. Inspection of the fill placement shall be provided by the Soils Engineer during the progress of grading. i tPage 5 - 1 F I 1 STANDARD GRADING SPECIFICATIONS B. In general, density tests should be made at intervals not exceeding 2 feet of fill height or every 500 cubic yards of fill placed. This criteria will vary depending on soil conditions and the size of the job. In any event, an adequate number of field density tests shall be made to verify that the required compaction is being achieved. C. Density tests should also be made on the surface material to receive fill as required by the Soils Engineer. D. All cleanouts, processed ground to receive fill, key excavations, subdrains, and rock disposals must be inspected and approved by the Soils Engineer or Engineering Geologist prior to placing any fill. It shall be the Contractor's responsibility to notify the Soils Engineer when such areas are ready for inspection. VI. CONSTRUCTION CONSIDERATIONS A. Erosion control measures, when necessary, shall be provided by the Contractor during grading and prior to the completion and construction of permanent drainage controls. t B. Upon completion of grading and termination of inspections by the Soils Engineer, no further filling or excavating, including that necessary for footings, foundations, large tree wells, retaining walls, or other features shall be performed without the approval of the Soils Engineer or Engineering Geologist. ' C. Care shall be taken by the Contractor during final grading to pre- serve any.berms, drainage terraces, interceptor swales, or other devices of permanent nature on or adjacent to the property. - Page 6 - 1 (OPI COMPACTED I FILL (F) —1J, 5' CUT LOT UNSUITABLE MATERIAL EXPOSED IN PORTION OF CUT PAD ORIGINAL GRADE j� _ N UT, ABLE MATERIABE,L ED OROCK WEATHER i COLLUVIUM. ��� (D) TOPSOIL, �' Or PROPOSED GRADE 5 Mn COMPETENT BEDROCK OR APPROVED FOUNDATION MATERIAL TYPICAL BENCHING (D) LOVEREXCAVATE AND RECOMPACT DEPTH OF FILL (F) Footing Depth to 3 feet --Equal Depth 3 to 6 feet ._ ._._�._. 3 feet Greater than 6 feet.---- One-half the thickness of fill placed on the "FILL" portion (F) to 15 feet maximum CUT -FILL TRANSITION LOT ORIGINAL GROUND r5o( PROPOSED GRADE,MinI-- r COMPACTED // �� t (D) FILL V\OG� ai TOP SOIt"�EO OEOR�� OVEREXCAVATE AND RECOMPACT COMPETENT BEDROCK OR i APPROVED FOUNDATION MATERIAL TYPICAL BENCHING IUT LOTS AND CUT -FILL TRANSITION LOTS PLATE SG -1 m• FINISHED GRADE CLEAR AREA FOR FOUNDATIONS, J -13' UTILITIES, AND SWIMMING POOLS-/ (� cc—:�- �- \ SLOPE FACE q• ,- is \ STREET WINDROW � T 5' OR BELOW DEPTH OF DEEPEST UTILITY TRENCH, WHICHEVER IS GREATER. TYPICAL WINDROW DETAIL (END VIEW) GRANDULAR SOIL FLOODED TO FILL VOIDS HORIZONTALLY PLACED. COMPACTED FILL 6 TO 8 INCH LIFTS PROFILE VIEW PICAL ROCK DISPOSAL DETAIL PLATE SG -2 FINISHED GRADE COMPACTED FILL TOE OF SLOPE AS SHOWN ON GRADING PLAN i `N � nonwvv x — NATURAL TOPOGRAPHY �� p0`pUV�UM• //� / 1:1 PROJECTION 2'/. min. i—— 15" MINIMUM — 2' MIN. DOWNSLOPE BASE KEY WIDTH KEY DEPTH BENCHING COMPETENT BEDROCK OR APPROVED FOUNDATION MATERIAL NOTE: WHERE NATURAL SLOPE GRADIENT IS 5:1 OR LESS BENCHING IS NOT NECESSARY; HOWEVER, FILL IS NOT TO BE PLACED ON COMPRESSIBLE OR UNSUITABLE MATERIAL. lob 1:_1.1_1 Q1 nom ARnvF MaTURAL SLOPE PLATE SG -3 I 11 I I 1] NATURAL GROUND UNSUITABLE MATERIAL TOPSOIL, ALLUVIUM, COLLUVIUM TYPICAL BENCHING 2 SEE DETAIL NOTE: FINAL 20 FEET OF PIPE AT OUTLET SHALL BE NON -PERFORATED. DEPTH AND BEDDING MAY VARY WITH PIPE AND LOAD CHARACTERISTICS. LCOMPETENT BEDROCK OR APPROVED FOUNDATION 18 -min MINIMUM 6 -INCH DIAMETER PVC SCHEDULE 40, OR ABS SDR- 35 WITH A MINIMUM OF 16 PERFORATIONS PER LINEAL FOOT IN BOTTOM HALF OF PIPE. PIPE TO BE LAID WITH PERFORATIONS DOWN. FOR CONTINUOUS RUNS IN EXCESS OF 500 FEET USE 8 -INCH DIAMETER PIPE. ,I\ I - CANYON SUBDRAIN DETAIL PLATE SG -4 FILTER MATERIAL- MINIMUM OF 9 CUBIC FEET PER LINEAL FOOT. SEE PLATE SG -6 FOR FILTER MATERIAL SPECIFICATIONS. ALTERNATE IN LIEU OF FILTER MATERIAL: v. 9 CUBIC FEET PER LINEAL FOOT OF OPEN -GRADED GRAVEL ENCASED IN FILTER FABRIC. SEE PLATE SG -6 FOR GRAVEL SPECIFICATIONS, E= FILTER FABRIC SHALL BE MIRAFI 140N OR APPROVED EQUAL. 18 -min MINIMUM 6 -INCH DIAMETER PVC SCHEDULE 40, OR ABS SDR- 35 WITH A MINIMUM OF 16 PERFORATIONS PER LINEAL FOOT IN BOTTOM HALF OF PIPE. PIPE TO BE LAID WITH PERFORATIONS DOWN. FOR CONTINUOUS RUNS IN EXCESS OF 500 FEET USE 8 -INCH DIAMETER PIPE. ,I\ I - CANYON SUBDRAIN DETAIL PLATE SG -4 I FINISHED. GRADE 2'min. IT 4- SUBDRAIN 2'/.min WIDTH VARIES (15' MIN.) TO TOP OF BACK CUT I" 15' MIN. FINISHED GRADE 4- SUBDRAIN � I � GJ 30' MAXIMUM SPACING 6� 1 .SEE DETAIL PLATE 5G-6 TYPICAL BENCHING NOTES: 1. Maximum vertical spacing of perforated pipe of 30 feet. 2. Maximum horizontal distance between non -perforated pipe of 100feet outlets. 3. Minimum gradient of one percent of all perforated pipe and non -perforated pipe and non-perf ora ted. outlet pipe. 100• Max OUTLET PIPE (TYPICAL) I PERFORATED PIPE (TYPICAL) BUTTRESS OR STABILIZATION FILL DETAIL PLATE SG -5 SLOPE FACE APPROVED FILTER MATERIAL. 5 CUBIC FEET PER LINEAR FOOT, A i WITHOUT FILTER FABRIC, 3 CUBIC 2% MINIMUM -T WITH FABRIC. A=`.`<-'' 4 -INCH PERFORATED PIPE WITH PERFORATIONS DOWN. MINIMUM 27. GRADE TO OUTLET PIPE. A Z4 -INCH NON -PERFORATED PIPE. MINIMUM 2/ GRADE TO OUTLET. APPROVED ON SITE MATERIAL PER SOILS ENGINEER COMPACTED TO A MINIMUM OF 907. MAXIMUM DENSITY. c E r I 4 -INCH NON -PERFORATED PIPE. I i 12" min. II SECTION A -A ' PIPE SPECIFICATIONS 1. 4 -INCH MINIMUM DIAMETER, PVC SCHEDULE 40, OR ABS SDR -35. 2. MINIMUM 16 PERFORATIONS PER FOOT ON BOTTOM ONE-THIRD OF PIPE. ' FILTER MATERIAL SPECIFICATIONS CLASS 2 PERMEABLE FILTER MATERIAL PER CALTRANS STANDARD SPECIFICATION 68-1.025. ' CLASS 2 SIEVE SIZE PERCENT PASSING ' 1 -INCH 100 3/4 -INCH 90-100 3/8 -INCH 40-100 NO. 4 25-40 NO. 8 18-33 NO. -30 5-15 NO. -50 0-7 NO. 200 0-3 ALTERNATE: OPEN GRADED GRAVEL ENCASED IN FILTER FABRIC. (MIRAFI 140N OR EQUAL) 1 OPEN -GRADED SIEVE SIZE 1 1/2 -INCH 1 -INCH 3/4 -INCH 3/8 -INCH NO. 200 PERCENT PASSING 88-100 5-40 0-17 0-7 0-3 UTTRESS OR STABILIZATION FILL SUBDRAIN PLATE SG -6 IV r O v m D 03 O m C-) C --i In r u m V'' i COMPACTED FILL � JE CUT/FILL CONTACT SHOWN ON GRADING PLAN /� Cli ep �-- SHOWN ON "AS-❑UILT�— Cp41-UVI_--- �� 4' TYPICAL REMOVE ALL TOPSOIL, COLLUVIUM, OR 09, CREEP ----�- CREEP MATERIAL FROM TRANSITION NATURAL TOPOGRAPHY CUT A" •-- 15' MINIMUM OR PER SOILS ENGINEER VARIES 10' TYPICAL BEDROCK OR APPROVED FOUNDATION MATERIAL m NATURAL TOPOGRAPHY i i i i' 1 -FINISHED GRADE 4' TYP. i 1 VARIES 10' (', TYP. 2% WN:> \"-COMPACTED FILL W --- BEDROCK OR APPROVED FOUNDATION MATERIAL NOTE: 1. SUBDRAINS NOT REQUIRED UNLESS SPECIFIED. 2. "W" SHALL BE EQUIPMENT WIDTH (15') FOR SLOPE HEIGHTS LESS THAN 30 FEET. FOR SLOPE HEIGHTS GREATER THAN 30 FEET -W" SHALL BE DETERMINED BY THE PROJECT SOILS ENGINEER. I 1A STABILIZATION FILL DETAIL PLATE SG -8 'p 1[ IL IU PROPOSED CUT LOT C, ♦GT INSTALL S -INCH PIPE SUBDR) PER, PLATES SG -4 AND SG -o" EXISTING TOPOGRAPHY PROPOSED DAYLIGHT CUT -RECONSTRUCT AT 1.5:1 OR FLATTER COMPACTED FILL W J� �G ?G NOTE: -W- SHALL BE 10 FEET MINIMUM OR AS DETERMINED BY THE PROJECT SOILS ENGINEER HEAR KEY ON DAYLIGHT CUT LOTS PLATE SG -9 1s E LLAIITS OF ROCK DISPOSAL 11 COMPETENT MATERIAL PER SOILS ENGINEER FDIISH SLOPE FACE 3' ROCK BLANKET (TYP.) 15' MDI �aaenda000 mm SECTION A -A' LMTS OF ROCK DISPOSAL 10' llvLDI. 2' MLV. 10'Vml;. �'�ooenL�oconnocod�aoan � ' � �oaon oaon Oo�DoLoo=o Ooo=n -' L�ooso0aaen OoaanOocon Coaen�ocoa - " "paoaoL�oo=a doaen�ooen �acec0ao=a L�aaonOocoa SECTION B -B' vLkTE.RL-�L. PER SOLI S ENGLNTR 1� 1126.6 11 .9 1126.6 126. 3 11:25.5 26 1 124.6 Jin �� � 125.6 1125.6 1 128. 1 1 15P 1157.9 118.7 1178.7 1177.8 mum. 1171.5 1172.7 164.7 ,8.6 1 147. 7 1142.2 1139.5 1136.7