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Home My WebLink AboutFINAL COMPACTION REPORT - TR 31792 FINAL COMPACTION REPORT OF GRADING • SOUTH SLOPE RESTORATION PROJECT FOR TRACT 31792,WASSON CANYON SITE CITY OF LAKE ELSINORE RIVERSIDE COUNTY,CALIFORNIA. FOR LENNAR HOMES 40.980 COUNTY CENTER ROAD,SUITE 100 TEMECULA,CALIFORNIA'92591 W.O.45.11-B1-SC FEBRUARY B,2007 Geotechnical • Geologic• Environmental s, �n Geotechnical • Coastal • Geologic • Environmental 26590 Madison Avenue Murrieta,California 92562 . (951)677-9651 - FAX(951)677-930'1 February 8, 2007 W.O. 4511-B 1-SC Lennar Homes 40980 County Center Road, Suite 100 Temecula, California 92591 Attention: Ms. Ellen Michiel Subject: Final Compaction Report of Grading, South Slope Restoration Project for Tract 31792, Wasson Canyon Site, City of Lake Elsinore, Riverside County, California Dear Ms. Michiel: In accordance with your request and authorization, GeoSoils, Inc. (GSI), is providing this final compaction report of grading for the south slope restoration project for Tract$1792, Wasson Canyon site, City of Lake Elsinore, Riverside County, California. The site was previously geotechnically investigated by GSI, and others (see the Appendix). GSI observed the restoration of the slope to original planned gradients with a rip-rap modification at the toe of the slope to account for creek scour in accordance with the approved restoration plans and analysis by SB&O, Inc. (SB&O, 2006a and 2006b). Grading and rip-rap placement within the area under purview of this report, began in December of 2006, and was generally completed in January of 2007. Based on the observations and testing performed by GSI, it is our opinion that the south slope restoration project for Tract 31792, appears suitable for its intended use, from a geotechnical viewpoint. Unless.specifically superceded herein,the recommendations and conclusions contained in the appropriate approved referenced reports by GSI (listed in the Appendix), remain pertinent and applicable and should be appropriately Implemented. BACKGROUND AND PURPOSE OF EARTHWORK Previous grading operations underthe observation Hilltop Geotechnical,Inc.(HGI,2004b) generally occurred onsite duringthe periodfrom November, 1993,through February,1994, in conjunction of the improvements for previous roadways alignments (CFD 90-3). However, the south slope area was not completed or graded to the elevations shown on the approved. plans (HGI, 2004a). In addition, concrete down-drains, landscaping, and general maintenance was never installed/conducted for the south slope area onsite. Subsequent to the previous placement of fills,and due to the general lack of maintenance and passage of time, localized erosion, scour, and general weathering of the slope area occurred.. Therefore,the general purpose of grading and rip-rap placement was to provide restoration of the previously placed compacted fills to the original proposed gradient of 2:1 (horizontal'to vertical [h:v]), and protect the toe of slope from additional creek scour and erosion. Typical cut/fill grading techniques were utilized to attain the desired graded configurations. The geotechnical Conditions exposed during the�process.of grading and rip-rap placement were observed on-a full.-time basis by representatives from our firm. Observations during the process of rough grading included removal of excess soil materials within the rip-rap placement area, installation of geotextile fabric, keyway construction,and compacted fill placement, along with the general grading procedures of the contractor, In general accordance the updated plans by SB&O (2006a). ENGINEERING GEOLOGY As described by GSI (2005), Tract 31972 may be characterized as being underlain by meta-sedimentary bedrock materials at depth, and locally exposed at the surface. Documented artificial fills, previously placed under the observation and testing services of HGI (2004b) encompass the majority of the area under the purview of this report. As indicated previously, due to the locally eroded and weathered nature of the previously placed and unlandscaped fill slope,and based on current standards of practice,the south slope areas of Tract 31792 adjoining Wasson Creek were restored to the original slope gradient of'2.:1. (h:v): In addition, preparation for concrete down-drain installation and rip- rap placement at the toe of the.slope was conducted in general accordance with the referenced reports and plans for the site (see the Appendix). In general,.the near surface, upper±1 to ±3 feet, of the previously documented artificial fill slope and/or bedrock was locally eroded,weathered,and loose, and considered unsuitable in its existing state,and therefore was removed and recompacted, if not removed as excess spoils for the installation of the rip-rap at ,the toe of the slope. Removals of unsuitable soils were performed in general accordance with the approved reports for the project. GROUNDWATER Regional groundwater was not encountered during grading of the area under the purview of this report and generally should not affect the proposed site development, provided our recommendations are properly implemented. Due to the contrasting nature of the onsite earth materials (i.e., compacted fill and bedrock), and due to the proximity of the south slope repair area to Wasson,Creek, the possibility of future flooding, localized perched water conditions, and seepage cannot be precluded, and should be anticipated. The potential for surface flooding, seepage and/or perched water conditions will increase during winter months and/or after periods of excessive/heavy rainfall. This potential should be disclosed to all interested/affected parties, homeowners, and any homeowners association. It is our understanding that the potential for flooding/scour etc., in this area has been.mitigated by the approved rip-rap design and configurations (SB&O, 2006a). Lennar Homea. W.O.4511-B1-SC Tract.31792, City of Lake Elsinore February 8,2007 File:eAwp10.\murrVc4 5 0 014 51 1b1.fcr Page 2 GeoSeft s, Inc. EARTHWORK CONSTRUCTION Earthwork operations have been completed in general accordance with recommendations provided in the field, based upon conditions exposed, in accordance with the controlling authorities requirements, and recommendations provided in the appropriate approved reports by GSI listed in the Appendix. Preparation of Existing Ground 1. Deleterious material, such as oversized rock, concentrated organic matter, and miscellaneous trash and debris, were stripped from the surface and disposed of offsite, prior to the placement of rip-rap and/or any fill materials. 2. Compressible undocumented fill, and/or eroded and weathered near surface documented artificial fill and/or bedrock were removed to expose competent artificial fill and/or bedrock, as defined in the approved referenced report by GSI (2005). 3. Subsequent to the above removals, the exposed subsoils were scarified to a depth of about 6 inches, brought to at least optimum moisture content,then compacted to a minimum relative compaction of 90 percent of the laboratory standard, per ASTM Test Method D-1557. Fill Placement 1. Fill materials, where placed, consisted of native offsite soils which were placed in 4-to 8-inch lifts,watered,and mixed to achieve at least optimum moisture conditions. Fills were compacted to a minimum relative compaction of 90 percent of the laboratory standard using earth scrapers, bulldozers, and/or water pulls/trucks. 2. Fills placed on sloping surfaces steeper than 5:1 (h:v) based upon pre-existing topography, were keyed and benched into competent documented fill and/or bedrock as per the approved referenced reports by GSI. Field Testing 1. Field density tests were performed using the nuclear (densometer) methods ASTM D-2922 and D-3017 and the sand-cone method ASTM D-1556. The test results are presented in the attached Table 1. The approximate locations of the field density tests are presented on the enclosed Plate 1, which utilize the 40-scale slope repair plans prepared by SB&O (2006a), as the base map. 2. Field density tests were taken at periodic intervals and selected locations to check the compactive efforts provided by the contractor. Where test results indicated less than optimum moisture content,and/or less than the minimum required 90 percent relative Lennar Homes W.O. 4511-61-SC Tract 31792,.City of Lake Elsinore February 8, 2007 File:e:\wp%murr\rc4500\4511 bl.fcr Page 3 GeoS®iils, Inc. compaction, the contractor was notified and the area was reworked until retesting indicated at least optimum moisture and a.minimurn relative compaction of90 percent were attained. Based upon the grading operations observed, the test results presented herein are 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. 4. Compaction tests have been numbered in a continuous sequence forthe entire slope repair process. Therefore, only those test results within the subject areas under the purview of this report, are included in Table 1 at the end of this report. SUBDRAINS General No seepage or perched waterwas encountered during rough grading and/or during rip-rap placement operations in the area under the purview of this report. Owing to the general lack of suitable cover (i.e., less than 10 feet of fill), lack of a suitable flowline gradient at removal bottoms, and,lack of a suitable outlet,subdrains were not placed during grading and rip-rap placement operations in the area under the purview of this report. However, existing' subdrain systems, placed under the observation and testing services of HGI (2004b)exist at depth. The approximate locations of the existing subdrainage systems are indicated on the enclosed Plate 1, based on the report of grading by HGI (2004.b). In the future if seepage or perched water conditions are observed at the toe of the south slope due to development, heavy/over-irrigation,and/or excessive precipitation, it should be mitigated by the granular nature of the onsite fill materials(generally derived from onsite metamorphic bedrock cuts),the permeable and general free-draining design of the rip-rap placed, and the.proximity of the south slope area to Wasson Creek. Due to the contrasting nature of the onsite earth materials (i.e., compacted fill and bedrock), and due to the proximity of the south slope repair area to Wasson Creek, the possibility of future flooding, localized perched water conditions, and seepage cannot be precluded, and should be anticipated. The potential for seepage and/or perched water conditions will increase during winter months and/or after periods of excessive/heavy rainfall. If, in the future, seepage or perched water conditions are observed due to heavy or over-irrigation,precipitation, or other factors not obvious during grading, GSI should'be contacted for recommendations for mitigation of the seepage and/or perched water conditions. Such conditions should be anticipated. The- potential for future seepage and/or perched water to occur after grading should be disclosed to all interested/affected parties, homeowners, and any homeowners association. Lennar Homes W.O. 4511-B1-SC Tract 31792,Cityr of Lake Elsinore February 8,2007 F11e:e:\wp10\tnurr\rc4500\4511 bl.fcr Page 4 GeoSoffs, 1we. LABORATORY TESTING Maximum Density Testing The laboratory maximum dry density and optimum moisture content for each of the major soil types-was determined according to Test Method ASTM D-1 557. The following table presents the results: Al -SOIL MAXIMUM DENSITY, OPTIMUM MOISTURE:. (%) -TY PE DESCR-PTION CONTENT. A Silty SAND w/Gravel, Brown 136.0 10.0 B Silty SAND w/Trace Gravel,Brown 135.0 9:0 C Silty SAND w/Gravel. Grayish Brown 128.0 11.0 CONCLUSIONS AND RECOMMENDATIONS Recommendations for development of the site were presented 1ri our referenced final compaction reports of grading and grading plan review (GSI; 2006a, 2006b, and 2005), which have been previously approved by the controlling authorities. All findings, conclusions, and recommendations in these reports,and other applicable reports by GSI for the site (see the Appendix), remain pertinent and applicable except as specifically superceded herein. General 1 Eroded debris may be minimized and surficial slope stability enhanced by establishing and maintaining a suitable vegetation cover soon after construction,and utilizing only that amount of irrigation necessary to sustain plant vigor. All slope areas should be properly landscaped and regularly maintained, including rip-rap areas. 2. The potential for surface flooding and/or scour is underthe purview of the design civil engineer. Recommendations for safety and/or mitigation of additional surface flooding and/or scour should be provided by the design civil engineer,as warranted. These additional recommendations should be provided to all interested/affected parties, homeowners, and any homeowners association. Lennar Homes W.O.4511-B1-SC Tract 31792,City of Lake Elsinore February 8,200.7 F11e:e:\wp1 O\murr\rr45OO\451 1 bl-.fcr Page 5 C.'-eolls So , Inc. TOP-OF-SLOPE WALLS/FENCES/IMPROVEMENTS Slope Creep 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 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 dessi catio n/swel ling 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 homeowners and homeowners 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. 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 Lennar Homes W.O. 4511-Bi-SC Tract 31792, City of Lake Elsinore February 8,2007 FAe:e:1wp10\murrlrc450014511 bl.fcr Page 6 GeoSoiis, hiCo 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 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 LIFE. Suitable mitigative measures to reducethe 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 homeowner and/or any homeowners association. Slope Maintenance and Planting Water has been shown to weaken the inherent strength of all earth materials. Slope stability is significantly reduced by overly wet conditions. Positive surface drainage away from slopes should be maintained and only the amount of irrigation necessary to sustain plant life should be provided for planted slopes. Over-watering should be avoided as it 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. t ltili7ing plants other than those recommended above will increase the potential for perched water, staining, mold, etc.,to develop. A rodent control program to prevent burrowing should be implemented. Irrigation of natural (ungraded) slope areas is generally not recommended. These recommendations regarding plant type; irrigation practices, and rodent control should be provided to each homeowner. Over-steepening of slopes should be avoided during building construction activities and landscaping. Lermar Homes W.O. 4511-B1-SC Tract 31792, City of Lake Elsinore February 8, 2007 F11e:eAwpl0\murr\rc4500\4511b1.fer Page 7 Geosoilsy klm. Drainage Adequate surface drainage is a very important factor in reducing the likelihood of adverse performance of down-drains and slopes. Surface drainage should be sufficient to prevent ponding of water anywhere, especially near the tops of slopes. Surface drainage should be carefully taken into consideration during fine grading and landscape construction. Therefore, care should be taken that future landscaping or construction activities do not create adverse drainage conditions. Positive site drainage within common areas should be provided and maintained at all times. Drainage should notflow uncontrolled down any descending slope. Water should be directed away from slopes and not allowed to pond and/or seep into the ground. Slope drainage should be directed toward the down-drain or other approved area(s). 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. Toe of Slope Drains/Toe Drains Where significant slopes intersect pad areas, surface drainage down the slope allows for some seepage into the subsurface materials, sometimes creating conditions causing or contributing to perched and/or ponded water. Toe of slope/toe drains may be beneficial in the mitigation of this condition due to surface drainage. The general criteria to be utilized by the design engineer for evaluating the need for this type of drain is as follows: • Is there a source of irrigation above or on the slope that could contribute to saturation of soil at the base of the slope? • Are the slopes hard rock and/or impermeable, or relatively permeable, or; do the slopes already have or are they proposed to have subdrains (i.e., stabilization fills, etc.)? • Are there cut-fill transitions (i.e., fill over bedrock), within the slope? • Was the lot at the base of the slope overexcavated or is it proposed to be overexcavated? Overexcavated lots located at the base of a slope could accumulate subsurface water'along the base of the fill cap. • Are the slopes north facing? North facing slopes tend to receive less sunlight (less evaporation) relative to south facing slopes and are more exposed to the currently prevailing seasonal storm tracks. • What is the slope height? It has been our experience that slopes with heights in excess of approximately 10 feet tend to have more problems due to storm runoff and irrigation than slopes of a lesser height. Lennar Homes W.O. 4511-B1-SC Tract 31792, City of Lake Elsinore February 8,2007 F11e:e:\wp10\murr\rc4500\451Ibi.fcr Page 8 GCOSOUS9 ZINC. • Do the slopes "toe out" into a residential lot or a lot where perched or ponded water may adversely impact its proposed use? Based on these general criteria,the construction of toe drains may be considered by the design engineer along the toe of slopes, or at retaining walls in slopes, descending to the rear of, such lots. Following are:Detail 1 (Schematic Toe Drain Detail) and Detail 2 (Subdrain Along Retaining Wall Detail). Other drains may be warranted due to unforeseen conditions, homeowner irrigation, or other circumstances. Where drains are constructed during grading, including subdrains, the locations/elevations of such drains should be surveyed, and recorded on the final as-built grading plans by the design engineer. It is recommended that the above be disclosed to all interested/affected parties, including homeowners and any homeowners association. Erosion Control Onsite earth materials have a moderate to high erosion potential. Cut and fill slopes will be subject to surficial erosion during and after grading. Consideration should be given to providing hay bales and silt fences for the temporary control of surface water, prior to the installation of landscaping, 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. Provisions should be made to drain the excess irrigation water from slope areas without saturating the subgrade below. 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. Subsurface and Surface Water As indicated previously, 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 assessthe 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. Lennar Homes W.O.4511-B1-SC Tract 31792, City of Lake Elsinore February 8, 2007 FIIe:eAw.pMrhurArc450014511bi.fbr Page 9 Geosoals, Inc. DETAILS N . T S SCHEMATIC TOE DRAIN DETAIL 0 S\oQe Drain May Be Constructed into, l01 or at,the Toe of Slope Pad Grade �., !r ,; � " NOTES., 1.) Soil Cap Compacted to 90 Percent Relative Compaction. 12"Minimum 2.) Permeable Material May Be Gravel Wrapped in Filter Fabric(Mirafi 140N or Equivalent). 3.) 4-Inch Diameter Perforated Pipe(SDR-35 or '< Equivalent)with Perforations Down. 4.) Pipe to Maintain a Minimum 1 Percent Fall, 5.) Concrete Cutoff Wall to be Provided at Transition ermeable to Solid Outlet Pipe. P Material 6.) Solid Outlet Pipe to Drain to Approved Area. 7.) Cleanouts are Recommended at Each Property 24" Line. Minimum Drain Pipe I •--- 12„ �-- SCHEMATIC TOE DRAIN DETAIL DETAIL 1 Geotechnical• Coastal • Geologic • Environmental DETAILS NT . S 2:1 SLOPE (TYPICAL) TOP OF WALL _ —\j BACKFILL WITH COMPACTED NOTES: NATIVE SOILS 1.) Soil Cap Compacted to 90 Percent _ _ __ _ Relative Compaction. 12" RETAINING WALL _ _ _ MIN 2.) Permeable Material May Be Gravel ___ _ _ _ Wrapped in Filter Fabric(Miraq 140N or Equivalent). 3.) 4-Inch Diameter Perforated Pipe "� -.• t SDR-35 or Equivalent)with YMIRAFI 140 FILTER FABRIC Perforations Down. FINISHED GRADE OR EQUAL <:. 4.) Pipe to Maintain a Minimum 1 a Percent Fall. �r 3/4"CRUSHED GRAVEL FT ,... 5.) Concrete Cutoff Wall to be Provided WALL FOOTING r at Transition to Solid Outlet Pipe. I ti 6.) Solid Outlet Pipe to Drain to !•,� '� Approved Area. 24" 7.) Cleanouts are Recommended at . .# Mlr 4"DRAIN Each Property Line. 4' 8.) Compacted Effort Should Be 1"TO Z' Applied to Drain Rock. 12 SUBDRAIN ALONG RETAINING WALL DETAIL NOT TO SCALE SUBDRAIN ALONG RETAINING WALL DETAIL e Q 1 . DETAIL 2 Geotechnical • Coastal • Geologic * Environmental Site Improvements/Additional Grading If in the future, any additional improvements are planned for the site, recommendations concerning the geological or geotechnical aspects of design and construction of said improvements could be provided upon request. improvements should not be constructed without specific design and construction recommendations from GSI,and this construction recommendation should also be provided to the homeowners, any homeowners association, and/or other interested/affected parties. This office should be notified in advance of any additional 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. Trenching/Temporary Construction Backcuts Considering the nature of the onsite earth materials, it should be anticipated that caving or sloughing could be a factor in all 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 homeowners,etc.,that may perform such work. 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 retaining wall footings, and free standing walls footings, prior to the placement of reinforcing steel or concrete. • During retaining wall subdrain installation, prior to backfill placement. _,Lennar Homes W.O.4511-Bi-SC Tract 31792, City of Lake Elsinore February 8,2007 File:Owp101rnurr1rc450014511b1.fcr Page 12 Gc®S®ills, Inc. • During placement of backfill for down-drains, utility line trenches,and retaining wall backfil I. • During slope construction/repair. • When any unusual soil conditions are encountered during any construction operations, subsequent to the issuance of this report. • 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 elements possibly applicable to the project. These criteria should not be considered as substitutes for actual designs by the structural engineer/designer. The structural engineer/designer should analyze actual soil-structure interaction and consider,as needed,expansive soil influence,and strength,stiffness and deflections in the various 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 bythe 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 improvement designer should confirm to GSI and the governing agency, in writing,that the proposed improvements can tolerate the amount of settlement and/or expansion characteristics and other design criteria specified herein. Lennar Homes W.O.4511-B1-SC Tract.31792, City of Lake Elsinore February 8, 2007 File:e:\wp10\rnurrVc4500\4511b1.1cr Page 13 Ge®S®its, Inc. PLAN REVIEW Final project plans (retaining wall, landscaping, etG.), 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, eitherexpress 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. Lennar Homes W.O.4511-B1-SC Tract 31792, City of Lake Elsinore February 8,2007 File:eAwplOUwrr\rc45O%4511b1.fcr Page 14 Gcos®nls, Jrnc. The opportunity to be of service is sincerely appreciated. If you should have any questions, please do not hesitate to contact our office. QPOFESS/py Respectfully submitted, o16AL Gp' y�� z.G �e'k, A.G Q` CaeoSoils, Inc. a ti� �'�, LU a No.GE2320 No.2377 Exp.1 CerlNled G P�' � Engineering Geologic% Q�` C CAL\F�2 r ' Todd A. Greer FOPc�,L�Fo Andrew T. Guatelll Engineering Geologist, CEG Geotechnical Engineer, GE 2320 TAG/JPF/ATG/jh/ps Enclosures: Table 1 - Field Density Test Results Appendix- References Plate 1 -As-Graded Geotechnical Map Distribution: (5) Addressee (2 wet signed) (1) SB&O, Inc., Attention: Mr. Martin Ohmstede Lennar Homes W.O. 4511-Bl-SC Tract 31792, City of Lake Elsinore February 8, 2007 FIIe:e:\wpl O�mrrkc4500\4511 bl.fcr Page 15 GeoSoils, Inca 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) N (pro N 1 12/13/06 Canyon Toe 56+20 31792 1337.0 11.4 123.6 90.9 NO A 2 12/13/06 Canyon Toe 55+00 31792 1336.0 10.6 124.8 91.8 ND A 3 12/14/06 Canyon Toe 56+60 31792 1347.0 10.4 123.2 90.6 ND A 4 12/14/06 Canyon Toe 55+20 31792 1348.0 10.2 122.8 90.3 ND A 5 12/15/06 Canyon 54+30 31792 1349.0 9.4 122.6 90.8 ND B 6* 12/15/06 Canvon 56+40 31792 1350.0 6.1 120.0 B6.9 ND B 6A 12/15/06 Canyon 56+40 31792 1350.0 9.8 127.2 94.2 ND B 7 12/15/06 1 Canyon 55+90 31792 1 1355.0 10.4 122.7 90.9 1 ND B 8 12/15/06 Canyon 53+50 31792 1348.0 9.7 122.3 90.6 NO B 9 12/18/06 Canyon 56+80 31792 1357.0 11.4 128.9 94.8 Sc A 10 12/18/06 Canyon 57+20 31792 1350.0 10.8 126.6 93.1 SC A 11* 12/19/06 Canyon 55+10 31792 1356.0 6.5 117.2 86.2 ND A 11 A 12/19/06 Canv_on 55+10 31792 1358.0 11.2 125.8 92.5 ND A 12 12/19/061 Canyon 57+50 31792 1350.0 10.7 123.2 90.6 ND A 13* 12/19/06 1 Canyon 56+10 31792 1360.0 7.2 121.3 89.2 ND A 13A 12/19/061 Canyon 56+10 31792 1360.0 10.4 124.3 91.4 ND A 14 12/20/06 1 Canyon 56+95 31792 1356.0 10.6 127.6 93.8 ND A 15 12/20/06 Canyon 57+90 31792 1354.0 10.9 126.1 92.7 ND A 16 12/20/06 Canyon 58+30 31792 1350.0 10.2 126.2 92.8 1 ND A 17 12/21/06 Canvon 57+50 31792 1359.0 9.2 124.7 92.4 ND B 18 12121/06 Canyon 58+30 31792 1355.0 9.0 123.9 91.8 ND B 19 12/21/06 Canyon 58+80 31792 1352.0 10.3 126.2 93.5 ND B 20 12122/061 Canyon 59+60 31792 1 1351.0 10.4 125.8 93.2 Sc B 21* 12/22/06 Canyon 59+00 31792 1355.0 8.2 119.0 87.5 Sc A 21A 12/22/06 Canyon 59+00 31792 1355.0 10.9 123.6 90.9 1 ND A 22 12/22/06 Canyon 59+50 31792 1354.0 9.2 124.9 92.5 ND B 23 12/22/06 Canyon 59+20 31792 1360.0 9.8 123.9 91.8 ND B 24 12/26/06 Canyon 59+90 31792 1355.0 10.8 127.6 93.8 ND A 25 12/26/06 Canyon 60+50 31792 1350.0 11.2 128.7 94.6 ND A 26 12/26/06 Canyon 50+40 31792 1355.0 10.4 126.1 92.7 ND A 27 12/27/06 Canyon 61+50 31792 1351.0 9.9 130.3 96.5 1 ND B 28 12/27/06 Canyon 61+00 31792 1355.0 9.4 123.1 91.2 ND B 29 12/27/06 Canyon 61+80 31792 1354.0 10.2 126.2 93.5. ND B 30 12/27/06 Canyon 61+40 31792 1360.0 9.7 125.7 93.1 ND B 31 12/28/06 Canyon 61+95 31792 1356.0 10.8 128.7 94.6 ND A 32 12/28/06 Canvon 61+80 31792 1359.0 11.2 126.3 92.9 ND A 33 12/28/06 Canyon 60+80 31792 1360.0 11.0 125.4 92.2 1 ND A 34 12/29/06 Canyon 62+50 31792 1350.0 11.2 127.6 93.8 ND A 35* 12/29/06 Canyon 62+10 31792 1360.0 9.7 120.5 88.6 ND A 35A 12/29/06 Canyon 62+10 31792 1360.0 11.4 128.1 94.2 ND A 36 12/29/06 Canyon 62+80 31792 1351.0 16.9 125.9 92.6 ND A 37 1/2/07 Canyon 62+80 31792 1355.0 10.8 125.3 92.1 ND A 38 112/07 Canyon 62+50 31792 1360.0 10.2 125.9 92.6 1 ND A 39 1/2/07 Canyon 62+30 31792 1363.0 11.3 1 125.0 91.9 ND A 40 1/2/07 Canyon 59+20 31792 1353.0 9.8 126.6 93.8 ND B 41 1/2/07 Canyon 60+20 31792 1358.0 10.2 130.8 96.2 ND A 42 1/2/07 Canyon 61+50 31792 1360.0 10.1 125.1 92.7 ND B 43 1 1/3/07 Canyon 62+95 31792 1368.0 10.8 126.2 92.8 ND A Lennar Homes W.O.4511-B1-SC Tract 31792,Clty of Lake Elsinore February,2007 File:Q\exce1ltables14511b1Jcr Page 1 GeoS(alls, Inc. Table 1 FIELD DENSITY TEST RESULTS TEST DATE TEST LOCATION TRACT ELEV MOISTURE . DRY,.: - REL TEST. SOIL NO, NO. OR CQNTENT DENSITY 'COMP METHOD TYPE DEPTH (K) 44 1/3/07 Canyon 63+50 31792 1356.0 11.2 124.4 91.5 ND A 45 1/3/07 Canyon 63+30 31792 1361.0 10.2 127.8 94.0 ND A 46 114/07 Canyon 63+90 31792 1359.0 10.8 124.7 91.7 ND A 47 1/4/07 Canyon 63+50 31792 1363.0 11.2 126.8 93.2 ND A 48 1/4/07 Canyon 64+20 31792 1360.0 11.4 128.5 94.5 ND A 49 1/4/07 Canyon 62+80 31792 1365.0 10.6 123.9 91.1 ND A 50 1/5/07 Canyon 64+50 31792 1359.0 10.8 125.0 92.6 ND B 51 1/5/07 1 Canyon 63+95 31792 1368.0 9.2 123.4 91.4 ND B 62 116/07 Canyon 64+30 31792 1365.0 9.1 124.1 91.9 ND B 53 118107 Canyon 63+50 31792 1365.0 9.6 121.8 90.2 ND B 54 118/07 Canyon 64.+90 31792 1360.0 10.2 125.7 93.1 ND B 55 1/9/07 Canyon 53+95 31792 1349.0 9.6 122.9 91.0 ND B 56 1/9/07 Canyon 53+40 31792 1 1343.0 10.2 121.8 90.2 1 ND B 57 1/9/07 Canyon 55+80 31792 1355.0 10.0 128.0 94.8 ND B 58 1/9/07 Canyon 56+40 31792 1352.0 9.4 131.4 97.3 ND B 59 1/9/07 Canyon 57+10 31792 1355.0 10.8 130.7 96.1 ND A 60 1/9/07 Canyon 58+00 31792 1350.0 10.5 129.9 95.5 SC A 61 1111/07 Canyon 64+80 31792 1366.0 10.6 124.7 91.7 ND A 62 1/11107 Canyon 65+20 31792 1 1361.0 11.4 128.9 1 94.8 ND A 63 1/11/07 Canyon 65+60 31792 1 1362.0 12.2 128.0 94.1 ND A 64 1/11/07 Canyon 65+30 31792 1365.0 11.0 130,8 96.2 ND A 65 1/11/07 Canyon 65+70 31792 1361.0 10.7 123.9 91.1 ND A 66 1/11107 Canyon 65+60 31792 1365.0 10.8 125.9 92.6 ND A 67 1/12/07 Canyon 65+90 31792 1362.0 10.4 122.5 90.1 ND A 6B 1/12/07 Canyon 65+80 31792 1366.0 11.6 124.7 91.7 ND A 69 1112/07 Canyon 65+10 31792 1 1365.0 11.2 122.7 90.2 ND A 70 1112/07 1 Canyon 65+50 31792 1368.0 10.7 128.2 94.3 ND A 71 1112/07 1 Canyon 52+72 31792 1342.0 10.0 123.7 91.6 ND B 72* 1/12/07 Canyon 53+00 31792 1343.0 9.4 113.7 84.2 1 ND B 72A 1/12107 Canyon 53+00 31792 1343.0 9.6 122.2 90.5 ND B 73 1/12/07 Canyon 52+65 31792 1345.0 9.5 122.6 90.8 ND B 74 1/15107 Gan on 52+50 31792 1338.0 12.7 115.6 90.3 ND C 75 1115/07 Canyon 52+10 31792 1343.0 13.0 116.5 91.0 SC C 76 1/15/07 1 Canyon 52+40 31792 1341.0 11.8 116.0 90.6 SC C 77 1/15/07 Canyon 51+50 31792 1 1346.0 11.9 119.6 93.4 1 SC C 78 1/15/07 Canyon 52+20 31792 1346.0 11.8 118.4 92.5 ND C 79 1115107 Canyon 51+20 31792 1353.0 12.9 117.2 91.6 ND C 80* 1/15/07 Canyon 51+80 31792 1350.0 10.0 113.4 8B.6 ND C 80A 1/15107 Canyon 51+80 31792 1350.0 11.4 116.4 90.9 ND C 81 1/15/07 1 Canyon 52+50 31792 1350.0 11.1 119.3 93.2 ND C 82 1/15/07 Canyon 52+30 31792 1355.0 11.7 120.4 1 94.1 1 ND C 63 1/15/07 Canyon 51+50 31792 1358.0 11.2 116.7 1 91.2 ND C LEGEND * = Failing Test A= Retest ND= Nuclear DensometerTest SC= Sand Cone Test Lennar Homes W.O.4511-B1-SC Tract 31792,City of Lake Elsinore February,2007 File:Q\excehtables\4511b1.fcr Page 2 Geosoils, hwg 'APPENDIX REFERENCES APPENDIX REFERENCES GeoSoils, Inc., 2006a, Final: compaction report of grading, lots 1 through 41, lots 109 through 119, lots 125 through 131, and lots 140 through 190,Tract 31792 (Magnolia/Primrose), City of Lake Elsinore, Riverside County, California, W.O. 4511-B-SC, dated August 29. 2006b,Memorandum-geotechnical review of SB&O plans for Tract 31792,Wasson Creet repair plan, Riverside County, California, W.O. 4511-B-SC, dated June 28. 2006c, Final compaction report of grading, Lots 132 through 139, Tract 31792, (Magnolia/Primrose Model Lots),City of Lake Elsinore,Riverside County,California, W.O. 4511-B-SC, dated May 11. 2005, Update geotechnical investigation and grading plan review (40-scale), Tract 31792, Wasson Canyon area, City of Lake Elsinore, Riverside County, California, W.O. 4511-B-SC, dated October 19. 2004, Summary of due diligence third-parry peer review,Tentative Tract No.31792, City of Lake Elsinore, Riverside County, California, W.O. 4511-A-SC, dated September 20. Geowest, 1991, Geotechnical feasibility study,tentative tract 25487, West of Elsinore Hill Road (proposed), Lake Elsinore area, California, project file no. 1032-201, dated June 25. Hilltop Geotechnical,Inc.,2004a,Updated geotechnical evaluation and review of tentative tract plan, Tentative Tract No. 31792, City of Lake Elsinore, Riverside County, California, project no. 362-A03, report no. 2, dated January 21, 2004b,Report of grading,portion of Tentative Tract No.31792,formerlyTract 25478 previous road alignment,City of Lake Elsinore,Riverside County,California,project no. 362-A03, report no. 1, dated January 21. SB&O, Inc., 2006a, Slope repair plan for: City of Lake Elsinore, Tract No. 31792, Wasson Creek, Sheets 1 through 3, 40-scale plans, WDID# 833C336126, dated November 7. 2006b, Wasson Canyon Creek, HEC-RAS analysis & RSP design report, City of Lake Elsinore, Tract 31792, Wasson Canyon, job no. 6351223, dated April 25. 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