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HomeMy WebLinkAboutFINAL PRECISE GRADING REPORT -P M 30832 FINAL PRECISE GRADING REPORT FOR PARCEL 9, PARCEL MAP 30832 LAKE ELSINORE, RIVERSIDE COUNTY, CALIFORNIA FOR CHUCK TIPPIE,GENERAL CONTRACTOR 40221 PASEO SERENO TEMECULA, CALIFORNIA 92594 W.O.5273-B-SC FEBRUARY 14,2007 0:6 -0S9- Geotechnical a Coastal • Geologic - Environmental 26590 Madison Avenue Murrieta, California 92562 • (951) 677-9651 • FAX(951) 677-9301 February 14, 2007 W.O. 5273-B-SC Chuck Tipple, General Contractor 40221 Paseo Sereno Temecula, California 92591 Subject: Final Precise Grading Report for Parcel 9, Parcel Map 30832, Lake Elsinore, Riverside County, California Dear Mr. Tippie: This report presents a summary of the geotechnical testing and observation services provided by GeoSoils, Inc. (GSI) during the precise grading phase of the development for Parcel 9, Parcel Map 30832, Lake Elsinore, Riverside County, California. Rough grading for this site was performed previously as documented in GSI (2003). Precise grading (under the purview of this report) within the project was conducted in February, 2007. Based on the observations and testing performed by GSI, it is our opinion that the subject building pad appears suitable for its intended use. Unless specifically superceded by recommendations presented herein,the recommendations and conclusions contained in the referenced reports (GSI, 2003 and 2006) remain pertinent and applicable, and should be appropriately implemented. PURPOSE OF EARTHWORK We understand that the parcel is to be developed for a commercial development, utilizing typical wood-frame type construction with slabs-on-grade and continuous footings. Building loads are assumed to be typical for this type of relatively light structure. If structural loads are more than atypical two-story building,the recommendations provided herein will need to be revised. Sewage disposal will be accommodated by tying into the regional system. ENGINEERING GEOLOGY The geotechnical conditions exposed during the process of grading were observed by representatives from our firm. Observations during the process of precise grading include removals and fill placement, along with the general grading procedures of the contractor. Earth materials encountered during earthwork construction at the subject tract included previously placed, compacted fill, as discussed in the approved referenced report (GSI, 2003). Adverse geologic structures were not observed. GROUNDWATER Regional groundwater was not encountered during grading and should not significantly affect the proposed site development, provided our recommendations are implemented. No significant canyons were present beneath the subject lot, and/or there were no outlets with a flowline gradient at removal bottoms. Therefore, subdrains were not placed during precise grading within the project. Due to the contrasting nature of the onsite earth materials,the possibility of future, localized perched water conditions and minor seepage cannot be precluded, and should be anticipated. This potential would increase on cut or shallow fill lots. Should such conditions become apparent within the project in the future, additional recommendations for mitigation may be provided upon request. This potential should be disclosed to all homeowners and any homeowners association, as well as all interested/affected parties. EARTHWORK CONSTRUCTION Earthwork operations have been completed in general accordance with recommendations provided in the field based upon conditions exposed and/or in accordance with the recommendations provided within the referenced reports by GSI. Pads and slopes should not sit fallow, and will need regular and periodic maintenance to function as intended. Irrigation should be limited to only that amount necessary to sustain plant vigor. Preparation of Existing Ground 1 . Deleterious material, such as concentrated organic matter and miscellaneous debris, were stripped from the surface and disposed of offsite, prior to placing any fill. 2. - "Compressible and weathered compacted fills were removed to the depths recommended in the referenced report by GSI (2006) and/or as recommended in the field during grading based on conditions exposed, in all areas to receive fills. 3. Subsequent to the above removals,the exposed subsoils were scarified to a depth of about 12 inches, moisture conditioned, as necessary, to at least optimum moisture content,then compacted to a minimum relative compaction of 90 percent of the laboratory standard. 4. Processing of removal bottoms was observed by a representative of GSI. Chuck Tipple, General Contractor W.O. 5273-B-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:a\wp7\murr\wopro\sc5200\5273b.fpg Page 2 Fill Placement 1 . Fill consisted of onsite soils that were placed in 4-to 8-inch lifts, watered, and mixed to achieve at least optimum moisture conditions, and compacted to a minimum relative compaction of 90 percent of the laboratory standard using typical earthmoving equipment. Field testing results are presented in the enclosed Table 1. 2. The approximate as-graded maximum depths of fill placed during precise grading was approximately 1 to 2 feet. Slopes No slopes were constructed during the precise grading operations. Previously existing fill slopes up to about ±3 feet in height descend from the pad to the adjacent street/pavement areas. All 2:1 (horizontal to vertical [h:v]) slopes are considered surficially and grossly stable and should remain so under normal conditions of care, maintenance, and rainfall. The potential for some erosion on slopes or unfinished or undeveloped building pads may be mitigated through suitable landscaping and strict adherence to the Development Criteria section of this report. All slopes should be landscaped as soon as possible. Field Testing 1 . Field density tests were performed using sand-cone method ASTM D-1556 and nuclear (densometer) methods ASTM D-2922 and D-3017. Field testing results at the subject lot are presented in the enclosed Table 1 . 2. Field density tests were taken at periodic intervals and selected locations to check the compactive effort provided by the contractor. Where test results indicated less than optimum moisture content, or less than 90 percent relative compaction, the contractor was notified and the area was reworked until retesting indicated at least optimum moisture and a minimum relative compaction of 90 percent were attained. Based upon the grading operations observed,the test results presented herein are Y.considered representative of the compacted fill. 3. Visual classification, supplemented by laboratory testing, was the basis for evaluating which maximum density value to use for a given density test. Chuck Tipple, General Contractor W.O. 5273-B-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:a\wp7\murr\wopro\sc5200\5273b.fpg Page 3 LABORATORY TESTING Moisture-Density Relations The laboratory maximum dry density and optimum moisture content for the major soil types were determined according to test method ASTM D-1557. The following table presents the results: SOIL TYPE DESCRIPTION MAXIMUM OPTIMUM MOISTURE DENSITY (PCF) CONTENT (%) D Brown, Silt Sand 127.0 9.5 Expansion Index Expansion Index (E.I.) tests were performed for the typical foundation soil types exposed at pad grade in general accordance with Standard #18-2 of the Uniform Building Code ([UBC], International Conference of Building Officials [ICBO], 1997). The E.I. test results of samples varied from 6 to 8. Therefore,the expansive potential of the soils for the subject lot may be classified as very low (i.e., E.I. between 0 and 20). Corrosion Analysis Representative samples of the site materials have been collected for soluble sulfate and corrosion potential testing. At the time of this report, these test results were not yet available. An addendum to this report will be provided when testing results are available. SETTLEMENT Per the approved referenced reports, we recommend that the structural foundations be designed in accordance with the latest edition of the UBC,and to withstand an over all total settlement of 2.2 inches and a differential settlement of 1.2 inches over a horizontal distance of 40 feet, or an angular distortion of 1/400. These settlement values should be evaluated by the project structural engineer and architect for potential impacts to the proposed improvements, foundations, and overlying buildings. SEISMIC SHAKING PARAMETERS Per Chapter 16 of the UBC/CBC (ICBO, 1997 and 2001), the following updated seismic design parameters are provided: Chuck Tipple, General Contractor W.O. 5273-13-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:a\wp7\murr\wopro\sc5200\5273b.fpg Page 4 Ct�on��mlc_ 7Jr..-,n_ UBC/CBC TABLE/FIGURE DESIGNATION FAULT PARAMETERS Seismic zone (per Figure 16-2*) 4 Seismic zone factor Z (per Table 16-1*) 0.40 Soil Profile Types (per Table 16-J*) Sp Seismic Coefficient Ca (per Table 16-Q*) 0.44 Na Seismic Coefficient C, (per Table 16-R*) 0.64 N, Near Source factor Na (per Table 16-S*) 1.3 Near Source factor N, (per Table 16-T*) 1.6 Distance to Seismic Source (Elsinore-Temecula) 1.3 mi. (2.1 km) Seismic Source Type (per Table 16-U*) B** Upper Bound Earthquake (Elsinore-Temecula) MW 6.8** * Figure and table references from Chapter 16 of the UBC/CBC (ICBO, 1997 and 2001). ** ICBO (199II). OTHER GEOLOGIC HAZARDS Based on our previous work on this project (see referenced reports), the potential for liquefaction, subsidence, or significant mass wasting within the site is considered low, provided our recommendations are properly implemented. FOUNDATION RECOMMENDATIONS General The foundation design and construction recommendations are based on laboratory testing and engineering analysis of onsite earth materials by GSI. If non-typical loads are anticipated, these recommendations will need to be revised. Recommendations for conventional and post-tensioned foundation systems are provided in the following sections and are not intended to preclude the transmission of water or water vapor through the foundations or slabs. The foundation systems may be used to support the proposed structures, provided they are founded in competent bearing material. The proposed foundation systems should be designed and constructed in accordance with the guidelines contained in the 1997 UBC. In the event that the information concerning the proposed development is not correct, or any changes in the design, location, or loading conditions of the proposed structure are made,the conclusions and recommendations contained in this report are for the currently proposed building within Parcel 9 only, and shall not be considered valid unless the Chuck Tippie, General Contractor W.O. 5273-B-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:e\wp7\murr\wopro\sc5200\5273b.fpg Page 5 changes are reviewed and conclusions of this report are modified or approved in writing by this office. The information and recommendations presented in this section are considered minimums and are not meant to supercede design(s) by the project structural engineer or civil engineer specializing in structural design. Upon request, GSI could provide additional consultation regarding soil parameters, as related to foundation design. The engineering analysis performed, concerning the foundation system and the recommendations offered below, have been prepared using typical, anticipated loads and assuming the recommended earthwork is performed. Conventional Foundation Design 1 . Conventional spread and continuous footings may be used to support the proposed residential structures provided they are founded entirely in properly compacted fill, as evaluated by GSI. 2. An allowable bearing value of 1,500 pounds per square foot (psf) may be used for design of footings which maintain a minimum width of 12 inches (continuous) and 24 inches square (isolated), and a minimum depth of at least 12 inches into the properly compacted fill. The bearing value may be increased by one-third for seismic or other temporary loads. The bearing value may be increased by 20 percent for each additional 12 inches in depth to a maximum of 2,500 psf. The increase in bearing value for footing width is not recommended. 3. For lateral sliding resistance, a 0.35 coefficient of friction may be utilized for a concrete to soil contact when multiplied by the dead load. 4. Passive earth pressure may be computed as an equivalent fluid having a density of 250 pounds per cubic foot (pcf) with a maximum earth pressure of 2,500 psf. 5. When combining passive pressure and frictional resistance, the passive pressure component should be reduced by one-third. 6. All footings should maintain a minimum 7-foot horizontal distance between the base of the footing and any adjacent descending slope, and minimally comply with the guidelines depicted on Figure No. 18-1-1 of the latest edition of the UBC. Foundation Construction The following foundation construction recommendations are presented as a minimum criteria from a soils engineering viewpoint and assume that the soils in the top 3 feet of finish grade would have a very low expansion potential. Recommendations by the project's design/structural engineer or architect, which exceeds the soils engineers' recommendations, should take precedence over the following minimum requirements: Chuck Tipple, General Contractor W.O. 5273-B-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:a\wp7\murr\wopro\sc5200\5273b.fpg Page 6 renCnil c p;:.,n 1. Continuous footings should be founded at a minimum depth of 12 and 18 inches below the lowest adjacent ground surface for one- and two-story floor loads, respectively, in accordance with the minimum requirements of the latest edition of the UBC. The structural engineer should review and approve these recommendations. Continuous interior footings may be founded at a minimum depth of 12 inches below the lowest adjacent ground surface. Footings for one-and two-story floor loads should have a minimum width of 12 and 15 inches, respectively, or as determined by the structural engineer or UBC criteria. Isolated pad footings should be at least 24 inches square in plan dimension and should have a minimum embedment of 18 inches, and minimally connected in one direction. 2. All footings should have a minimum of one No. 4 reinforcing bar placed at the top and one No. 4 reinforcing bar placed at the bottom of the footing. Isolated interior or exterior piers and columns should be founded at a minimum depth of 18 inches below the lowest adjacent ground surface. Pad footings should be reinforced per structural requirements. 3. Concrete slabs in structural areas, including garage slabs,should be underlain with a vapor retarder consisting of a minimum of 10-mil, polyvinyl-chloride membrane with all laps sealed, per the UBC/CBC (ICBO, 1997 and 2001). This membrane should be and covered with a minimum of 2 inches of sand to aid in uniform curing of the concrete and prevent puncturing of the vapor retarder. 4. A grade beam, reinforced as above and at least 12 inches square, should be provided across garage or large entrances. The base of the reinforced grade beam should be at the same elevation as the adjoining footings. 5. Concrete slabs,including garage slabs,should be a minimum of 4 inches thick,and reinforced with No. 3 reinforcement bars placed on 18-inch centers, in two horizontally perpendicular directions (i.e., long axis and short axis). All slab reinforcement should be supported to ensure proper mid-slab height positioning -during placement of the concrete. "Hooking"of reinforcement is not an acceptable method of positioning. The design engineer should determine the actual thickness of concrete slabs based upon proposed loading and use. 6. Garage slabs should be poured separately from other structural footings and be quartered with expansion joints or saw cuts. A positive separation from the footings should be maintained with expansion joint material to permit relative movement. 7. Expansion joints should be provided for all slabs in accordance with the recommendations of the project engineer. Chuck Tippie, General Contractor W.O. 5273-B-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:a\wp7\murr\wopro\sc5200\5273b.fpg Page 7 8. Specific presaturation is not required for these soil conditions; however, the moisture content of the subgrade soils should be equal to or greater than optimum moisture to a depth of 12 inches below the adjacent ground grade in the slab areas, and evaluated by this office within 72 hours of the vapor retarder placement. 9. Soils generated from footing excavations to be used onsite should be compacted to a minimum relative compaction 90 percent of the laboratory standard, whether it is to be placed inside the foundation perimeter or in the yard/right-of-way areas. This material must not alter positive drainage patterns that direct drainage away from the structural areas and toward the street. 10. As an alternative, an engineered post-tension foundation system may be used. Engineering parameters for post-tension design can be provided upon request. POST-TENSIONED SLAB DESIGN As an alternative, post-tension designs may be utilized. For post-tension designs, the recommendations presented below should be followed in addition to those contained in the previous sections. The information and recommendations presented in this section are not meant to supercede design by a registered structural engineer or civil engineer familiar with post-tensioned slab design or corrosion engineering consultant. Upon request, GSI could provide additional data/consultation regarding soil parameters as related to post- tensioned slab design. From a soil expansion/shrinkage standpoint,afairly common contributing factorto distress of structures using post-tensioned slabs is a significant fluctuation in the moisture content of soils underlying the perimeter of the slab, compared to the center, causing a "dishing" or "arching" of the slabs. To mitigate this possible phenomenon, a combination of soil presaturation and construction of a perimeter "cut-off" wall grade beam should be employed. Perimeter foundations should be a minimum of 12 inches deep for very low expansive soils and at determined by the post-tension designer. The perimeter foundations may be integrated into the slab design or independent of the slab. The cut-off walls should be a minimum of 6 inches in width. In moisture-sensitive slab areas, a vapor retarder should be utilized and be of sufficient thickness to provide a durable separation of foundation from soils (10 mils. thick). For very low expansive soils the slabs should be underlain with a vapor retarder consisting of a minimum of 10-mil, polyvinyl-chloride membrane with all laps sealed, per the UBC/CBC (ICBO, 1997 and 2001). This membrane should be covered with a minimum of 2 inches of sand to aid in uniform curing of the concrete. The vapor retarder may be placed on the slab subgrade. Specific soil presaturation is not required; however, the moisture content of the subgrade soils should be at, or above, the soils' optimum moisture content to a depth of 12 inches below grade. Chuck Tipple, General Contractor W.O. 5273-B-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:a\wp7\murr\wopro\sc5200\5273b.fpg Page 8 Post-tension slabs should be designed in accordance with the recommendations of the Post-Tensioning Institute method. Based on review of laboratory data for the onsite materials, the average soil modulus subgrade reaction K, to be used for design, is 100 pounds per cubic inch (pci). This is equivalent to a surface bearing value of 1,000 psf. Post-Tensioning Institute (PTI) Method Post-tensioned slabs should have sufficient stiffness to resist excessive bending due to non-uniform swell and shrinkage of subgrade soils. The differential movement can occur at the corner, edge, or center of slab. The potential for differential uplift can be evaluated using Section 1816 of the UBC/CBC (ICBO, 1997 and 2001), based on design specifications of the Post-Tensioning Institute. The following table presents suggested minimum coefficients to be used in the Post-Tensioning Institute design method. Thornthwaite Moisture Index -20 inches/year Correction Factor for Irrigation 20 inches/year Depth to Constant Soil Suction 7 feet Constant soil Suction (pf) 3.6 Modulus of Subgrade Reaction (pci) 75 Moisture Velocity 0.7 inches/month The coefficients are considered minimums and may not be adequate to represent worst case conditions such as adverse drainage and/or improper landscaping and maintenance. The above parameters are applicable provided structures have gutters and downspouts and positive drainage is maintained away from structures. Therefore, it is important that information regarding drainage, site maintenance, settlements, and effects of expansive soils be passed on to future owners. BasQd,on the above parameters,the following values were obtained from figures or tables of Section 1816 of the UBC/CBC (ICBO, 1997 and 2001). The values may not be appropriate to account for possible differential settlement of the slab due to other factors. If a stiffer slab is desired, higher values of ym may be warranted. E.I. OF SOIL SUBGRADE VERY LOW E.I. E.I. OF SOIL SUBGRADE I VERY LOW E.I. em center lift 5.0 feet ym center lift 1.0 inches em ed a lift 1 2.5 feet ym edge lift 0.3 inches Chuck Tipple, General Contractor W.O. 5273-B-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:e\wp7\murr\wopro\sc5200\5273b.fpg Page 9 re..c..:tW 7-0h Should open bottom planters (containers) be planned directly adjacent to the foundation system, the values in the above tables would need to be reviewed and/or modified to reflect more highly variable moisture fluctuations along the edges of the foundations. Deepened footings/edges around the slab perimeter must be used to minimize non-uniform surface moisture migration (from an outside source) beneath the slab. An edge depth of 12 inches should be considered a minimum. The bottom of the deepened footing/edge should be designed to resist tension, using cable or reinforcement per the structural engineer. Other applicable recommendations presented underthe conventional foundation section should be adhered to during the design and construction phase of the project. SOIL MOISTURE CONSIDERATIONS It should be noted that the foundation construction recommendations provided herein are not intended to preclude the transmission of water or vapor through the slab, as indicated in current code. Foundation systems and slabs shall not allow water or water vapor to enter into the structure so as to cause damage to another building component, or to limit the installation of the type of flooring materials typically used for the particular application (State of California,2006). Therefore,the following should be considered by the structural engineer/foundation/slab designer to mitigate the transmission of water or water vapor through the slab. • Concrete slabs should be a minimum of 5 inches thick for very low expansive soil conditions, and be minimally reinforced as previously discussed. All slab reinforcement should be supported to provide proper mid-slab height positioning during placement of the concrete. "Hooking"of reinforcement is not an acceptable method of positioning. Increase of concrete slab thickness would tend to reduce moisture vapor transmission though slabs. • Concrete slab underlayment should consist of a 10-mil to 15-mil vapor retarder, or equivalent, with all laps sealed per the UBC/CBC (ICBO, 1997 and 2001) and the "manufacturer's recommendation. The vapor retarder should comply with the ASTM E-1745 Class A or B criteria and be installed per the recommendations of the manufacturer, including all penetrations (i.e., pipe, ducting, rebar, etc.). The manufacturer shall provide instructions for lap sealing, including minimum width of lap, method of sealing,and either supply or specify suitable products for lap sealing (ASTM E-1745). In order to break the capillary rise of soil moisture, the vapor retarder should be underlain by 2 inches of fine or coarse, washed, clean gravel (80 to 100 percent greater than #4 sieve) and be overlain by at least 2 inches of clean, washed sand (SE >30) to aid in concrete curing. • Concrete should have a maximum water/cement ratio of 0.50. Chuck Tipple, General Contractor W.O. 5273-B-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:e\wp7\murr\wopro\sc5200\5273b.fpg Page 10 • Where slab concrete compressive strength is increased, admixtures used, and water/cement ratios are adjusted herein,the structural consultant should also make changes to the concrete in the grade beams and footings in kind so that the concrete used in the foundation and slabs are designed and/or treated for more uniform moisture protection. • The use of a penetrating slab surface sealer may be considered in rooms where permeable floor tile or wood will be used. In all planned floorings,the waterproofing specialist should review the manufacturer's recommendations and adjust installation as needed. Homeowner(s) should be advised which areas are suitable for tile or wood floors. • Additional recommendations regarding water or vapor transmission should be provided by the architect/structural engineer/slab or foundation designer. Please be aware that the above should be implemented if the transmission of water or water vapor through the slab is undesirable. Should these recommendations not be implemented, then full disclosure of the potential for water or vapor to pass through the foundations and slabs and resultant distress should be provided to all interested parties, in writing. Regardless of the mitigation,some limited moisture/moisture vapor transmission through the slab should be anticipated. WALL DESIGN PARAMETERS Conventional Retaining Walls The design parameters provided below assume that either non expansive soils (typically Class 2 permeable filter material or Class 3 aggregate base) or native onsite materials (up to and including an E.I. of 65) are used to backfill any retaining walls. The type of backfill (i.e., select or native), should be specified by the wall designer, and clearly shown on the plans. Building walls, below grade, should be water-proofed. The foundation system for the proposed retaining walls should be designed in accordance with the recommendations presented in this and preceding sections of this report, as appropriate. Footings should be embedded a minimum of 18 inches below adjacent grade (excluding landscape layer, 6 inches) and should be 24 inches in width. There should be no increase in bearing for footing width. Recommendations for specialty walls (i.e., crib, earthstone, geogrid, etc.) can be provided upon request, and would be based on site specific conditions. Restrained Walls Any retaining walls that will be restrained prior to placing and compacting backfill material or that have re-entrant or male corners, should be designed for an at-rest equivalent fluid Chuck Tipple, General Contractor W.O. 5273-B-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:a\wp7\murr\wopro\sc5200\5273b.fpg Page 11 pressure (EFP) of 65 pounds per cubic foot (pcf), plus any applicable surcharge loading. For areas of male or re-entrant corners, the restrained wall design should extend a minimum distance of twice the height of the wall (21-1) laterally from the corner. Cantilevered Walls The recommendations presented below are for cantilevered retaining walls up to 10 feet high. Design parameters for walls less than 3 feet in height may be superceded by City and/or County standard design. Active earth pressure may be used for retaining wall design, provided the top of the wall is not restrained from minor deflections. An equivalent fluid pressure approach may be used to compute the horizontal pressure against the wall. Appropriate fluid unit weights are given below for specific slope gradients of the retained material. These do not include other superimposed loading conditions due to traffic, structures, seismic events or adverse geologic conditions. When wall configurations are finalized,the appropriate loading conditions forsuperimposed loads can be provided upon request. SURFACE SLOPE OF EQUIVALENT EQUIVALENT RETAINED MATERIAL FLUID WEIGHT P.C.F. FLUID WEIGHT P.C.F. (HORIZONTAL:VERTICAL) (SELECT BACKFILL) (NATIVE BACKFILL) Level* 35 T 45 2 to 1 50 60 * Level backfill behind a retaining wall is defined as compacted earth materials, properly drained, without a slope for a distance of 2H behind the wall. Retaining Wall Backfill and Drainage Positive drainage must be provided behind all retaining walls in the form of gravel wrapped in geofabric and outlets. A backdrain system is considered necessary for retaining walls that are 2 feet or greater in height. Details 1, 2, and 3, present the back drainage options discussed below. Backdrains should consist of a 4-inch diameter perforated PVC or ABS pipe,encased in either Class 2 permeable filter material or 3/4-inch to 1'/2-inch gravel wrapped in approved filter fabric (Mirafi 140 or equivalent). For low expansive backfill, the filter material should extend a minimum of 1 horizontal foot behind the base of the walls and upward at least 1 foot. For native backfill that has up to medium expansion potential, continuous Class 2 permeable drain materials should be used behind the wall. This material should be continuous (i.e., full height) behind the wall, and it should be constructed in accordance with the enclosed Detail 1 (Typical Retaining Wall Backfill and Drainage Detail). For limited access and confined areas, (panel) drainage behind the wall may be constructed in accordance with Detail 2 (Retaining Wall Backfill and Subdrain Detail Geotextile Drain). Materials with an E.I. potential of greater than 65 should not be used as backfill for retaining walls. For more onerous expansive situations, backfill and Chuck Tipple, General Contractor W.O. 5273-B-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:a\wp7\murr\wopro\sc5200\5273b.fpg Page 12 DETAILS N T . S . 2 Native Backfill Provide Surface Drainage Slope or Level Native Backfill 12" +12" Rock Filter Fabric (!)Waterproofing 1 Membrane(optional) 1 or Flatter Weep Hole Native Backfill Finished Surface • �w ® Pipe WATERPROOFING MEMBRANE (optional): Liquid boot or approved equivalent. ® ROCK: 3/4,to 1-1/2" (inches) rock. FILTER FABRIC: Mirafi 140N or approved equivalent; place fabric flap behind core. ® PIPE: 4" (inches) diameter perforated PVC. schedule 40 or approved alternative with minimum of 1% gradient to proper outlet point (Perforations down). ® WEEP HOLE: Minimum 2" (inches) diameter placed at 20' (feet) on centers along the wall, and 3" (inches) above finished surface (No weep holes for basement walls.). TYPICAL RETAINING WALL BACKFILL AND DRAINAGE DETAIL • DETAIL 1 Geotechnical 9 Coastal • Geologic • Environmental DETAILS N T S . 2 Native Backfill Provide Surface Drainage Slope or Level ` Native Backfill OWaterproofing Membrane(optional) Drain � Weep Hole 1 or Flatter Filter Fabric Finished Surface - ® Pipe 0 © WATERPROOFING MEMBRANE (optional): Liquid boot or approved equivalent. ® DRAIN: Miradrain 6000 or]-drain 200 or equivalent for non-waterproofed walls. Miradrain 6200 or]-drain 200 or equivalent for waterproofed walls (All Perforations down). O FILTER FABRIC: Mirafi 140N or approved equivalent; place fabric flap behind core. ® PIPE: 4" (inches) diameter perforated PVC. schedule 40 or approved alternative with minimum of 1% gradient to proper outlet point. ® WEEP HOLE: Minimum 2" (inches) diameter placed at 20' (feet) on centers along the wall, and 3" (inches) above finished surface. (No weep holes for basement walls.) RETAINING WALL BACKFILL AND SUBDRAIN DETAIL GEOTEXTILE DRAIN DETAIL 2 Geotechnical • Coastal • Geologic • Environmental DETAILS N T S . 2 Native Backfill Provide Surface Drainage Slope or Level +JrY` E H/2 ' + min. +12" Waterproofing 1 Membrane(optional) 1 or Flatter H . © Weep Hole • Clean Sand Backfill Filter Fabric _ Finished Surface ® Roc Pipe Heel Width © WATERPROOFING MEMBRANE (optional): Liquid boot or approved equivalent. ® CLEAN SAND BACKFILL: Must have sand equivalent value of 30 or greater; can be densified by water jetting. OO FILTER FABRIC: .T Mirafi 140N or approved equivalent. ® ROCK: 1 cubic foot per linear feet of pipe or 3/4 to 1-1/2" (inches) rock. ® PIPE: 4" (inches) diameter perforated PVC. schedule 40 or approved alternative with minimum of 1% gradient to proper outlet point (Perforations down). ®WEEP HOLE: Minimum 2" (inches) diameter placed at 20' (feet) on centers along the wall, and 3" (inches) above finished surface. (No weep holes for basement walls.) RETAINING WALL AND SUBDRAIN DETAIL CLEAN SAND BACKFILL 9 • DETAIL 3 Geotechnical • Coastal • Geologic • Environmental drainage behind the retaining wall should conform with Detail 3 (Retaining Wall And Subdrain Detail Clean Sand Backfill). Outlets should consist of a 4-inch diameter solid PVC or ABS pipe spaced no greater than ±100 feet apart, with a minimum of two outlets, one on each end. The use of weep holes, only, in walls higher than 2 feet, is not recommended. The surface of the backfill should be sealed by pavement or the top 18 inches compacted with native soil (E.I. <90). Proper surface drainage should also be provided. For additional mitigation, consideration should be given to applying a water-proof membrane to the back of all retaining structures. The use of a waterstop should be considered for all concrete and masonry joints. Wall/Retaining Wall Footing Transitions Site walls are anticipated to be founded on footings designed in accordance with the recommendations in this report. Should wall footings transition from cut to fill, the civil designer may specify either: a) A minimum of a 2-foot overexcavation and recompaction of cut materials for a distance of 2H, from the point of transition. b) Increase of the amount of reinforcing steel and wall detailing (i.e., expansion joints or crack control joints) such that a angular distortion of 1/360 for a distance of 2H on either side of the transition may be accommodated. Expansion joints should be placed no greater than 20 feet on-center, in accordance with the structural engineer's/wall designer's recommendations,regardless of whether or nottransition conditions exist. Expansion joints should be sealed with aflexible, non-shrink grout. c) Embed the footings entirely into native formational material (i.e., deepened footings). If transitions from cut to fill transect the wall footing alignment at an angle of less than 45 degrees (plan view), then the designer should follow recommendation "a" (above) and until such transition is between 45 and 90 degrees to the wall alignment. TOP-OF-SLOPE WALLS/FENCES/IMPROVEMENTS Slope Creep Some soils at the site may be expansive and therefore, may become desiccated when allowed to dry. Such soils are susceptible to surficial slope creep,especially with seasonal changes in moisture content. Typically in southern California, during the hot and dry summer period, these soils become desiccated and shrink, thereby developing surface cracks. The extent and depth of these shrinkage cracks depend on many factors such as Chuck Tipple, General Contractor W.O. 5273-B-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:a\wp7\murr\wopro\sc5200\5273b.fpg Page 16 Ron Cn;:1 c ]Nf/" the nature and expansivity of the soils, temperature and humidity, and extraction of moisture from surface soils by plants and roots. When seasonal rains occur, water percolates into the cracks and fissures, causing slope surfaces to expand, with a corresponding loss in soil density and shear strength near the slope surface. With the passage of time and several moisture cycles, the outer 3 to 5 feet of slope materials experience a very slow, but progressive, outward and downward movement, known as slope creep. For slope heights greater than 10 feet, this creep related soil movement will typically impact all rear yard flatwork and other secondary improvements that are located within about 15 feet from the top of slopes, such as swimming pools, concrete flatwork, etc., and in particular top of slope fences/walls. This influence is normally in the form of detrimental settlement,and tilting of the proposed improvements. The dessication/swelling and creep discussed above continues over the life of the improvements, and generally becomes progressively worse. Accordingly,the developer should provide this information to any owners and/or owners association. Top of Slope Walls/Fences Due to the potential for slope creep for slopes higher than about 10 feet, some settlement and tilting of the walls/fence with the corresponding distresses, should be expected. To mitigate the tilting of top of slope walls/fences, we recommend that the walls/fences be constructed on deepened foundations without any consideration for creep forces, where the expansion index of the materials comprising the outer 15 feet of the slope is less than 50. The strength of the concrete and grout should be evaluated by the structural engineer of record. The proper ASTM tests for the concrete and mortar should be provided along with the slump quantities. The concrete used should be appropriate to mitigate sulfate corrosion, as warranted. The design of the walls should be in accordance with the recommendations of the project structural engineer, and include the utilization of the geotechnical parameters provided herein. DRIVEWAY, FLATWORK, AND OTHER IMPROVEMENTS The soil materials on site may be expansive. The effects of expansive soils are cumulative, and typically occur over the lifetime of any improvements. On relatively level areas, when the soils are allowed to dry, the dessication and swelling process tends to cause heaving and distress to flatwork and other improvements. The resulting potential for distress to improvements may be reduced, but not totally eliminated. To that end, it is recommended that the developer should notify any owners or owners association of this long-term potential for distress. To reduce the likelihood of distress,the following recommendations are presented for all exterior flatwork: 1 . The subgrade area for concrete slabs should be compacted to achieve a minimum 90 percent relative compaction, and then be presoaked to 2 to 3 percentage points above (or 125 percent of) the soils' optimum moisture content, to a depth of Chuck Tipple, General Contractor W.O. 5273-B-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:a\wp7\murr\wopro\sc5200\5273b.fpg Page 17 18 inches below subgrade elevation. If very low expansive soils are present, only optimum moisture content, or greater, is required and specific presoaking is not warranted. The moisture content of the subgrade should be proof tested within 72 hours prior to pouring concrete. 2. Concrete slabs should be cast over a non-yielding surface, consisting of a 4-inch layer of crushed rock, gravel, or clean sand, that should be compacted and level prior to pouring concrete. If very low expansive soils are present,the rock or gravel or sand may be deleted. The layer or subgrade should be wet-down completely prior to pouring concrete,to minimize loss of concrete moisture to the surrounding earth materials. 3. Exterior slabs should be a minimum of 4 inches thick. Driveway slabs and approaches should additionally have a thickened edge (12 inches) adjacent to all landscape areas, to help impede infiltration of landscape water under the slab. 4. The use of transverse and longitudinal control joints are recommended to help control slab cracking due to concrete shrinkage or expansion. Two ways to mitigate such cracking are: a) add a sufficient amount of reinforcing steel, increasing tensile strength of the slab; and, b) provide an adequate amount of control and/or expansion joints to accommodate anticipated concrete shrinkage and expansion. In order to reduce the potential for unsightly cracks, slabs should be reinforced at mid-height with a minimum of No. 3 bars placed at 18 inches on center, in each direction. If subgrade soils within the top 7 feet from finish grade are very low expansive soils (i.e., E.I. s2O), then 6x6-W1.4xW1.4 welded-wire mesh may be substituted for the rebar, provided the reinforcement is placed on chairs, at slab mid-height. The exterior slabs should be scored or saw cut, '/2 to 3/8 inches deep, often enough so that no section is greater than 10 feet by 10 feet. For sidewalks or narrow slabs, control joints should be provided at intervals of every 6 feet. The slabs should be separated from the foundations and sidewalks with expansion joint filler material. 5. No traffic should be allowed upon the newly poured concrete slabs until they have been properly cured to within 75 percent of design strength. Concrete compression strength should be a minimum of 2,500 psi. 6. Driveways, sidewalks, and patio slabs adjacent to the house should be separated from the house with thick expansion joint filler material. In areas directly adjacent to a continuous source of moisture (i.e., irrigation, planters, etc.), all joints should be additionally sealed with flexible mastic. 7. Planters and walls should not be tied to the house. Chuck Tipple, General Contractor W.O. 5273-B-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:a\wp7\murr\wopro\sc5200\5273b.fpg Page 18 8. Overhang structures should be supported on the slabs, or structurally designed with continuous footings tied in at least two directions. If very low expansion soils are present, footings need only be tied in one direction. 9. Any masonry landscape walls that are to be constructed throughout the property should be grouted and articulated in segments no more than 20 feet long. These segments should be keyed or doweled together. 10. Utilities should be enclosed within a closed utilidor (vault) or designed with flexible connections to accommodate differential settlement and expansive soil conditions. 11. Positive site drainage should be maintained at all times. Finish grade on the lots should provide a minimum of 1 to 2 percent fall to the street, as indicated herein. It should be kept in mind that drainage reversals could occur, including post-construction settlement, if relatively flat yard drainage gradients are not periodically maintained by the owner or owners association. 12. Air conditioning (A/C) units should be supported by slabs that are incorporated into the building foundation or constructed on a rigid slab with flexible couplings for plumbing and electrical lines. A/C waste water lines should be drained to a suitable non-erosive outlet. 13. Shrinkage cracks could become excessive if proper finishing and curing practices are not followed. Finishing and curing practices should be performed per the Portland Cement Association Guidelines. Mix design should incorporate rate of curing for climate and time of year, sulfate content of soils, corrosion potential of soils, and fertilizers used on site. DEVELOPMENT CRITERIA Slope Deformation Compacted fill slopes designed using customary factors of safety for gross or surficial stability and constructed in general accordance with the design specifications should be expected to undergo some differential vertical heave or settlement in combination with differential lateral movement in the out-of-slope direction, after grading. This post-construction movement occurs in two forms: slope creep, and lateral fill extension (LFE). Slope creep is caused by alternate wetting and drying of the fill soils which results in slow downslope movement. This type of movement is expected to occur throughout the life of the slope, and is anticipated to potentially affect improvements or structures (e.g., separations and/or cracking), placed near the top-of-slope, up to a maximum distance of approximately 15 feet from the top-of-slope, depending on the slope height. This movement generally results in rotation and differential settlement of improvements located Chuck Tipple, General Contractor W.O. 5273-B-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:e\wp7\murr\wopro\sc5200\5273b.fpg Page 19 within the creep zone. LFE occurs due to deep wetting from irrigation and rainfall on slopes comprised of expansive materials. Although some movement should be expected, long-term movement from this source may be minimized, but not eliminated, by placing the fill throughout the slope region, wet of the fill's optimum moisture content. It is generally not practical to attempt to eliminate the effects of either slope creep or LFE. Suitable mitigative measures to reduce the potential of lateral deformation typically include: setback of improvements from the slope faces (per the 1997 UBC and/or adopted California Building Code), positive structural separations (i.e., joints) between improvements, and stiffening and deepening of foundations. Expansion joints in walls should be placed no greater than 20 feet on-center, and in accordance with the structural engineer's recommendations. All of these measures are recommended for design of structures and improvements. The ramifications of the above conditions, and recommendations for mitigation, should be provided to each owner and/or any owners association. Slope Maintenance and Planting Water has been shown to weaken the inherent strength of all earth materials. Slope stability is significantly reduced by overly wet conditions. Positive surface drainage away from slopes should be maintained and only the amount of irrigation necessary to sustain plant life should be provided for planted slopes. Over-watering should be avoided as it adversely affects site improvements,and causes perched groundwater conditions. Graded slopes constructed utilizing onsite materials would be erosive. Eroded debris may be minimized and surficial slope stability enhanced by establishing and maintaining a suitable vegetation cover soon after construction. Compaction to the face of fill slopes would tend to minimize short-term erosion until vegetation is established. Plants selected for landscaping should be light weight, deep rooted types that require little water and are capable of surviving the prevailing climate. Jute-type matting or other fibrous covers may aid in allowing the establishment of a sparse plant cover. Utilizing plants other than those recommended above will increase the potential for perched water, staining, mold, etc., to develop. A rodent control program to prevent burrowing should be implemented. Irrigation of natural (ungraded) slope areas is generally not recommended. These recommendations regarding plant type, irrigation practices, and rodent control should be provided to all owners. Over-steepening of slopes should be avoided during building construction activities and landscaping. Drainage Adequate lot surface drainage is a very important factor in reducing the likelihood of adverse performance of foundations, hardscape,and slopes. Surface drainage should be sufficient to prevent ponding of water anywhere on a lot,and especially near structures and tops of slopes. Lot surface drainage should be carefully taken into consideration during fine grading, landscaping, and building construction. Therefore,care should be taken that Chuck Tipple, General Contractor W.O. 5273-B-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:e\wp7\murr\wopro\sc5200\5273b.fpg Page 20 future landscaping or construction activities do not create adverse drainage conditions. Positive site drainage within lots and common areas should be provided and maintained at all times. Drainage should not flow uncontrolled down any descending slope. Water should be directed away from foundations and not allowed to pond and/or seep into the ground. In general, the area within 5 feet around a structure should slope away from the structure. We recommend that unpaved lawn and landscape areas have a minimum gradient of 1 percent sloping away from structures, and whenever possible, should be above adjacent paved areas. Consideration should be given to avoiding construction of planters adjacent to structures (buildings, pools, spas, etc.). Pad drainage should be directed toward the street or other approved area(s). Although not a geotechnical requirement, roof gutters, down spouts, or other appropriate means may be utilized to control roof drainage. Down spouts, or drainage devices should outlet a minimum of 5 feet from structures or into a subsurface drainage system. Areas of seepage may develop due to irrigation or heavy rainfall, and should be anticipated. Minimizing irrigation will lessen this potential. If areas of seepage develop, recommendations for minimizing this effect could be provided upon request. Erosion Control Cut and fill slopes will be subject to surficial erosion during and after grading. Onsite earth materials have a moderate to high erosion potential. Consideration should be given to providing hay bales and silt fences for the temporary control of surface water, from a geotechnical viewpoint. Landscape Maintenance Only the amount of irrigation necessary to sustain plant life should be provided. Over-watering the landscape areas will adversely affect proposed site improvements. We would recommend that any proposed open-bottom planters adjacent to proposed structures be eliminated for a minimum distance of 10 feet. As an alternative, closed-bottom type planters could be utilized. An outlet placed in the bottom of the planter, could be installed to direct drainage away from structures or any exterior concrete flatwork. If planters are constructed adjacent to structures, the sides and bottom of the planter should be provided with a moisture retarder to prevent penetration of irrigation water into the subgrade. Provisions should be made to drain the excess irrigation water from the planters without saturating the subgrade below or adjacent to the planters. Graded slope areas should be planted with drought resistant vegetation. Consideration should be given to the type of vegetation chosen and their potential effect upon surface improvements (i.e., some trees will have an effect on concrete flatwork with their extensive root systems). From a geotechnical standpoint leaching is not recommended for establishing landscaping. If the surface soils are processed for the purpose of adding amendments, they should be recompacted to 90 percent minimum relative compaction. Chuck Tipple, General Contractor W.O. 5273-B-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:a\wp7\murr\wopro\sc5200\5273b.fpg Page 21 : Fa sm Gutters and Downspouts As previously discussed in the drainage section,the installation of gutters and downspouts should be considered to collect roof water that may otherwise infiltrate the soils adjacent to the structures. If utilized, the downspouts should be drained into PVC collector pipes or other non-erosive devices (e.g., paved swales or ditches; below grade, solid tight-lined PVC pipes; etc.), that will carry the water away from the house,to an appropriate outlet, in accordance with the recommendations of the design civil engineer. Downspouts and gutters are not a requirement; however, from a geotechnical viewpoint, provided that positive drainage is incorporated into project design (as discussed previously). Subsurface and Surface Water Subsurface and surface water are not anticipated to affect site development, provided that the recommendations contained in this report are incorporated into final design and construction and that prudent surface and subsurface drainage practices are incorporated into the construction plans. Perched groundwater conditions along zones of contrasting permeabilities may not be precluded from occurring in the future due to site irrigation,poor drainage conditions, or damaged utilities, and should be anticipated. Should perched groundwater conditions develop,this office could assess the affected area(s) and provide the appropriate recommendations to mitigate the observed groundwater conditions. Groundwater conditions may change with the introduction of irrigation, rainfall, or other factors. Site Improvements If in the future, any additional improvements (e.g., pools, spas, etc.) are planned for the site, recommendations concerning the geological or geotechnical aspects of design and construction of said improvements could be provided upon request. Pools and/or spas should not be constructed without specific design and construction recommendations from GSI,and this construction recommendation should be provided to the owners,any owners association, and/or other interested parties. This office should be notified in advance of any fill placement, grading of the site, or trench backfilling after rough grading has been completed. This includes any grading, utility trench and retaining wall backfills, flatwork, etc. Tile Flooring Tile flooring can crack, reflecting cracks in the concrete slab below the tile, although small cracks in a conventional slab may not be significant. Therefore, the designer should consider additional steel reinforcement for concrete slabs-on-grade where tile will be placed. The tile installer should consider installation methods that reduce possible cracking of the tile such as slipsheets. Slipsheets or a vinyl crack isolation membrane (approved by the Tile Council of America/Ceramic Tile Institute) are recommended between tile and concrete slabs on grade. Chuck Tippie, General Contractor W.O. 5273-B-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:a\wp7\murr\wopro\sc5200\5273b.fpg Page 22 at:�on�n�lc_ I!Is.vn_ Additional Gradinq This office should be notified in advance of any fill placement, supplemental regrading of the site, or trench backfilling after rough grading has been completed. This includes completion of grading in the street, driveway approaches, driveways, parking areas, and utility trench and retaining wall backfills. Footing Trench Excavation All footing excavations should be observed by a representative of this firm subsequent to trenching and 2rior to concrete form and reinforcement placement. The purpose of the observations is to evaluate that the excavations have been made into the recommended bearing material and to the minimum widths and depths recommended for construction. If loose or compressible materials are exposed within the footing excavation, a deeper footing or removal and recompaction of the subgrade materials would be recommended at that time. Footing trench spoil and any excess soils generated .from utility trench excavations should be compacted to a minimum relative compaction of 90 percent, if not removed from the site. Trench in /Temporary Construction Backcuts Considering the nature of the onsite earth materials, it should be anticipated that caving or sloughing could be a factor in subsurface excavations and trenching. Shoring or excavating the trench walls/backcuts at the angle of repose (typically 25 to 45 degrees [except as specifically superceded within the text of this report]), should be anticipated. All excavations should be observed by an engineering geologist or soil engineer from GSI, prior to workers entering the excavation or trench, and minimally conform to CAL-OSHA, state, and local safety codes. Should adverse conditions exist, appropriate recommendations would be offered at that time. The above recommendations should be provided to any contractors and/or subcontractors, or owners,etc.,that may perform such work. Utility Trench Backfill 1 . All interior utility trench backfill should be brought to at least 2 percent above optimum moisture content and then compacted to obtain a minimum relative compaction of 90 percent of the laboratory standard. As an alternative for shallow (12-inch to 18-inch) under-slab trenches, sand having a sand equivalent value of 30 or greater may be utilized and jetted or flooded into place. Observation, probing and testing should be provided to evaluate the desired results. 2. Exterior trenches adjacent to, and within areas extending below a 1:1 plane projected from the outside bottom edge of the footing, and all trenches beneath hardscape features and in slopes, should be compacted to at least 90 percent of Chuck Tippie, General Contractor W.O. 5273-B-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:a\wp7\murr\wopro\sc5200\5273b.fpg Page 23 t1 e0_B.�innflc_ IJ-iao_ the laboratory standard. Sand backfill, unless excavated from the trench, should not be used in these backfill areas. Compaction testing and observations, along with probing, should be accomplished to evaluate the desired results. 3. All trench excavations should conform to CAL-OSHA, state, and local safety codes. 4. Utilities crossing grade beams, perimeter beams, or footings should either pass below the footing or grade beam utilizing a hardened collar or foam spacer, or pass through the footing or grade beam in accordance with the recommendations of the structural engineer. SUMMARY OF RECOMMENDATIONS REGARDING GEOTECHNICAL OBSERVATION AND TESTING We recommend that observation and/or testing be performed by GSI at each of the following construction stages: • During grading/recertification. • During excavation. • During placement of subdrains, toe drains, or other subdrainage devices, prior to placing fill and/or backfill. • After excavation of building footings,retaining wall footings, and free standing walls footings, prior to the placement of reinforcing steel or concrete. • Prior to pouring any slabs or flatwork, after precooking/presaturation of building pads and other flatwork subgrade, before the placement of concrete, reinforcing steel, capillary break (i.e., sand, pea-gravel, etc.), or vapor retarders (i.e., visqueen, etc.). • During retaining wall subdrain installation, prior to backfill placement. • During placement of backfill for area drain, interior plumbing, utility line trenches, and retaining wall backfill. • During slope construction/repair. When any unusual soil conditions are encountered during any construction operations, subsequent to the issuance of this report. Chuck Tipple, General Contractor W.O. 5273-B-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:a\wp7\murr\wopro\sc5200\5273b.fpg Page 24 fioanJ�SaAf1Q f0:.,A • When any developer or owner improvements, such as flatwork, spas, pools, walls, etc., are constructed, prior to construction. GSI should review the plans for such improvements prior to construction. • A report of geotechnical observation and testing should be provided at the conclusion of each of the above stages, in order to provide concise and clear documentation of site work, and/or to comply with code requirements. OTHER DESIGN PROFESSIONALS/CONSULTANTS The design civil engineer, structural engineer, post-tension designer, architect, landscape architect, wall designer, etc., should review the recommendations provided herein, incorporate those recommendations into all their respective plans, and by explicit reference, make this report part of their project plans. This report presents minimum design criteria for the design of slabs,foundations and other elements possibly applicable to the project. These criteria should not be considered as substitutes for actual designs by the structural engineer/designer. Please note that the recommendations contained herein are not intended to preclude the transmission of water or vapor through the slab or foundation. The structural engineer/foundation and/or slab designer should also provide recommendations to not allow water or vapor to enter into the structure so as to cause damage to another building component, or so as to limit the installation of the type of flooring materials typically used for the particular application. Such recommendations may include a thicker slab,thicker underlayment, 4,000 psi concrete with a water-cement ratio of 0.5, etc. Owners should be advised of the potential for Water or vapor transmission through foundations and slabs. The structural engineer/designer should analyze actual soil-structure interaction and consider, as needed, bearing, expansive soil influence, and strength, stiffness and deflections in the various slab, foundation, and other elements in order to develop appropriate, design-specific details. As conditions dictate, it is possible that other influences will also have to be considered. The structural engineer/designer should consider all applicable codes and authoritative sources where needed. If analyses by the structural engineer/designer result in less critical details than are provided herein as minimums,the minimums presented herein should be adopted. It is considered likely that some, more restrictive details will be required. If the structural engineer/designer has any questions or requires further assistance, they should not hesitate to call or otherwise transmit their requests to GSI. In order to mitigate potential distress, the foundation and/or improvement's designer should confirm to GSI and the governing agency, in writing,that the proposed foundations and/or improvements can tolerate the amount of differential settlement and/or expansion characteristics and other design criteria specified herein. Chuck Tipple,General Contractor W.O. 5273-B-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:a\wp7\murr\wopro\sc5200\5273b.fpg Page 25 �anC��1c Ts•n PLAN REVIEW Final project plans (grading, precise grading,foundation,retaining wall, landscaping,etc.), should be reviewed by this office prior to construction, so that construction is in accordance with the conclusions and recommendations of this report. Based on our review, supplemental recommendations and/or further geotechnical studies may be warranted. LIMITATIONS The materials encountered on the project site and utilized for our analysis are believed representative of the area; however, soil and bedrock materials vary in character between excavations and natural outcrops or conditions exposed during mass grading. Site conditions may vary due to seasonal changes or other factors. Inasmuch as our study is based upon our review and engineering analyses and laboratory data, the conclusions and recommendations are professional opinions. These opinions have been derived in accordance with current standards of practice, and no warranty, either express or implied, is given. Standards of practice are subject to change with time. GSI assumes no responsibility or liability for work or testing performed by others, or their inaction; or work performed when GSI is not requested to be onsite, to evaluate if our recommendations have been properly implemented. Use of this report constitutes an agreement and consent by the user to all the limitations outlined above, notwithstanding any other agreements that may be in place. In addition, this report may be subject to review by the controlling authorities. Thus, this report brings to completion our scope of services for this portion of the project. All samples will be disposed of after 30 days, unless specifically requested by the client, in writing. Chuck Tipple, General Contractor W.O. 5273-B-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:a\wp7\murr\wopro\sc5200\5273b.fpg Page 26 The opportunity to be of service is sincerely appreciated. If you should have any questions, please do not hesitate to contact our office. Respectfully submitt W Q& QpFES3 � �l2 �SwWq��Fy GeoSoils, Inc. L Q -4 Reviewed h X, GRltl�d NO. 22 8 � EnglnNAnp - Exp. / -:, Q�ol Irt - _ < l��FCH �G�OP?ter Paul L. McClay �-Ben Shahrvinl of CXO Engineering Geologist, G 1117 Geotechnical Engineer, GE 2296 PLM/JPF/BBS/jh/ps Enclosures: Table 1 - Field Density Test Results Appendix - References Distribution: (4) Addressee Chuck Tippie, General Contractor W.O. 5273-B-SC Parcel 9, Parcel Map 30832, Lake Elsinore February 14, 2007 File:e\wp7\murr\wopro\sc5200\5273b.fpg Page 27 GeoSoils, Inc. Table 1 FIELD DENSITY TEST RESULTS TEST DATE TEST LOCATION TRACT ELEV MOISTURE DRY REL TEST SOIL NO. NO. OR CONTENT DENSITY COMP METHOD TYPE DEPTH ft 9'° cf BT-1 2/6/07 Pad 9 30832 1298.0 9.8 120.4 94.8 ND D BT-2 2/6/07 Pad 9 30832 1298.0 10.1 119.2 93.9 ND D 3 2/6/07 Pad 9 30832 1298.0 10.3 117.5 92.6 ND D 4 2/6/07 Pad 9 30832 1298.0 9.9 116.6 91.9 Sc D BT-5 2/7/07 Pad 9 30832 1298.0 9.5 115.9 91.3 ND D BT-6 2/7/07 Pad 9 30832 1298.0 9.8 114.8 90.5 ND D BT-7 2/7/07 Pad 9 30832 1298.0 9.6 117.5 92.6 ND D 8 2/7/07 Pad 9 30832 1298.0 10.4 116.1 91.4 ND D 9 2/7/07 Pad 9 30832 1298.0 9.9 118.8 93.6 SC D 10 2/7/07 Pad 9 30832 1298.0 10.5 117.1 92.2 ND D 11* 2/7/07 Pad 9 30832 1299.0 9.8 112.4 88.6 ND D 11A 2/7/07 Pad 9 30832 1299.0 10.0 116.4 91.7 ND D 12 2/7/07 Pad 9 30832 1299.0 9.6 115.3 90.8 ND D 13 2/7/07 Pad 9 30832 1299.0 10.2 117.1 92.3 SC D 14 2/7/07 Pad 9 30832 1299.0 10.6 115.5 91.0 ND D 15 2/8/07 Pad 9 30832 FG 9.8 116.4 91.7 ND D 16 2/8/07 Pad 9 30832 FG 10.6 116.8 92.0 ND D 17 2/8/07 Pad 9 30832 FG 9.9 117.5 92.6 ND D 18 2/8/07 Pad 9 30832 FG 10.5 114.9 90.5 SC D 19 2/12/07 Parking Area 30832 FG 10.6 116.9 92.1 ND D 20 2/12/07 Parking Area 30832 FG 10.9 115.3 90.8 ND D 21 2/12/07 Parkinq Area 30832 FG 9.8 117.7 92.7 ND D 22 2/12/07 Parkinq Area 30832 FG 10.2 116.6 91.9 SC D 23 2/12/07 Parkinq Area 30832 FG 10.4 114.9 90.5 ND D LEGEND * = Failing Test A = Retest FG = Finish Grade ND = Nuclear Densometer Test SC = Sand Cone Test Chuck Tippie, General Contractor W.O. 5273-B-SC Parcel 9 of PM 30832 February, 2007 File:C:\excel\tables\5273b.tbl.xls Page 1 APPENDIX REFERENCES APPENDIX REFERENCES GeoSoils, Inc., 2006, Geotechnical update report, Parcel 9, Parcel Map 30832, Lake Elsinore, Riverside County, California,W.O. 5273-A-SC, dated September 20. 2003, Compaction report of grading, building pads for Parcels 1, 2, and 9 of Parcel 4, Parcel Map 29235, Summerhill Commercial Center, Lake Elsinore, Riverside County, California, W.O. 3278-B-SC dated May 30 International Conference of Building Officials, 2001, California building code, California code of regulations title 24, part 2, volume 1 and 2. 1997, Uniform building code: Whittier, California, vol. 1, 2, and 3. State of California, 2006, Civil Code, Sections 896-897. %j'ew` oils. Tine.