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HomeMy WebLinkAboutGeotechnical Rpt Lots 102-114 pse 10 11/12/2003�Ilin.9 99 %40'- PETRA OFFICES IN THE COUNTIES OF ORANGE • SAN DIEGO • RIVERSIDE • LOS ANGELES • SAN BERNARDINO November 12, 2003 J.N. 188-01 BGR No. 010340 RICHMOND AMERICAN HOMES 100 East San Marcos Boulevard, Suite 100 San Marcos, California 92069 Attention: Mr. Gary McCoy Subject: Geotechnical Report of Rough Grading, Lots 102 through 114 (Phase 10), Tract 23066-3, Temecula Area, Riverside County, California This report presents a summary of the observation and testing services provided by Petra Geotechnical, Inc. (Petra) during rough -grading of Lots 102 through 114 (Phase 10) within Tract 23066-3 located in the Temecula area of Riverside County, California. Conclusions and recommendations pertaining to the suitability of the grading for the proposed residential construction are provided herein, as well as foundation -design recommendations based on the as -graded soil conditions. REGULATORY COMPLIANCE Cuts, removals of unsuitable low-density surface soils, transition -lot overexcavations and capping and placement of compacted fill under the purview of this report have been completed under the observation and with selective testing by Petra. The earthwork was performed in accordance with the recommendations presented in previ-ous geotechnical reports by Petra (see References) and the grading code of the County of Riverside. The completed earthwork has been reviewed and is considered adequate for the construction now planned. On the basis of our observations, as well as field and PETRA GEOTECHNICAL, INC. 41640 Corning Place • Suite 107 n Murrieta . CA 92562 . Tel: (909) 600-9271 • Fax: (909) 600-9215 M RICHMOND AMERICAN HOMES November 12, 2003 TR 23066-3 Lots 102-114/Temecula Area J.N. 188-01 Page 2 laboratory testing, the recommendations presented in this report were prepared in ' conformance with generally accepted professional engineering practices in the area and no further warranty is implied nor made. 1 SUMMARY OF AS -GRADED SOIL AND GEOLOGIC CONDITIONS As -Graded Conditions and Remedial Grading Remedial grading included overexcavations of low-density/surficial soils on the order of 3 to 15 feet deep and the overexcavation and fill placement within the cut and shallow fill portions of cut/fill transition lots. The compacted fills ranged in thickness 0 from approximately 7 to 45 feet. A lot -by -lot summary of the compacted -fill depths and a summary of soil conditions is presented in the attached Table I. A general ' description of the as -graded soil and bedrock materials underlying the subject lots is provided below and are shown on the attached Geotechnical Map with Density Test ' Locations (Figure 1). ' Artificial Fill - Compacted (map symbol afc) — Compacted -fill soils placed during grading were comprised of onsite -derived and imported soil and bedrock materials and consisted generally of fine to coarse sand, silty sand and clayey sand. Imported ' materials were generated from adjacent properties. • Pauba Formation Bedrock (Ons) — In general, the Pauba Formation consisted of ' dense, fine-grained and well -graded sandstones, clayey sandstone and clay beds with occasional gravel and cobble beds. A cross -bedded, well -graded, friable sand unit was also observed within the bedrock. Groundwater ' No groundwater or seepage was encountered during site grading. i 3 RICHMOND AMERICAN HOMES November 12, 2003 TR 23066-3 Lots 102-114/Temecula Area J.N. 188-01 Page 3 SUMMARY OF EARTHWORK OBSERVATIONS AND DENSITY TESTING Clearing and Grubbing Vegetation that existed in localized areas, as well as some construction debris, were removed from the site. Ground Preparation Prior to placing structural fill, existing low-density surfrcial soils or weathered bedrock were first removed to competent undisturbed bedrock. Overexcavations varied from approximately 3 to 15 feet. Prior to placing fill, exposed bottom surfaces in removal areas were observed by a Petra representative. Following this observation, the exposed bottom surfaces were scarified to depths of approximately 6 to 8 inches, watered or air-dried as necessary to achieve a moisture content equal to or slightly above optimum moisture content and then compacted by rolling with loaded scrapers. Subdrain A subdrain system consisting of 6- and 8 -inch diameter perforated pipe and gravel enclosed with filter fabric was installed within the canyon bottoms and drainage courses. Furthermore, a canyon subdrain was placed in the canyon area north of Lots 112 through 114. Due to the depth of removal below the proposed toe -of -slope, fill was placed in the canyon bottom to allow 1 or more percent fall exiting approximately 2 feet above toe -of -slope. The approximate location of the subdrains is shown on the attached Figure 1. ' _/e ,2 "�J -c�, -3 s D 0 0 I [1 RICHMOND AMERICAN HOMES November 12, 2003 TR 23066-3 Lots 102-114/Temecula Area J.N. 188-01 Page 4 Cut/Fill Transition Lots To reduce the potential for distress to residential structures related to the differential settlement, the cut portions of cut/fill transition Lots 102 through 104 and 110 through 114 were overexcavated to a depth of approximately 7 to 10 feet below finish grade and capped with compacted fill derived from onsite materials. Fill Slopes Fill slopes were constructed at a ratio of approximately 2:1 (h:v) and to heights of up to approximately 50 feet. The graded -fill slopes were overfilled during construction and then track -walked to achieve compaction to the slope face. Fill slopes were constructed on level keys which were approximately 15 feet wide and excavated into Pauba Formation bedrock. The fill slopes are considered grossly and surficially stable to the heights and inclinations at which they are constructed. Cut Slopes No cut slopes were constructed within the subject lots during this phase of grading. Fill Placement and Testing Fill soils were placed in thin lifts, watered or air-dried as necessary to achieve near - optimum moisture conditions and then compacted in-place. Compaction was achieved by wheel -rolling with a compactor or loaded scrapers. The deepest fill placed within the subject lots was approximately 45 feet on Lot 108. Field density and moisture content tests were performed in accordance with nuclear - gauge test methods (ASTM D2922 and D3017). Occasional field density tests were also performed in accordance with the sand -cone method (ASTM D1556). Field density test results are presented in the attached Table II and approximate test locations are shown on Figure 1. • D 0 RICHMOND AMERICAN HOMES November 12, 2003 TR 23066-3 Lots 102-114/Temecula Area J.N. 188-01 Page 5 Field density tests were taken at vertical intervals of approximately 1 to 2 feet. The compacted fills were tested at the time of placement to document that the specified moisture content and relative compaction had been achieved. One in-place density test was taken for approximately each 1,000 cubic yards of fill placed and/or for each approximately 2 feet in vertical height of compacted fill. The actual number of tests taken per day varied with the project conditions, such as the number of eartlmnovers (scrapers) and availability of support equipment. When field density tests produced results less than the specified relative compaction of 90 percent or if the soils were found to be above or below a recommended moisture content, the approximate limits of the substandard fill were established. The substandard area was then either removed or reworked in-place. Visual classification of earth materials in the field was the basis for determining which dry density value was applicable for a given density test. LABORATORY TESTING Laboratory Maximum Dry Density Maximum dry density and optimum moisture content of representative samples of fill soils were determined in our laboratory in accordance with ASTM D1557. Pertinent test values are summarized in Appendix A. Expansion Index Tests Expansion index tests were performed on representative samples of soil existing at or near finish -pad grade within the subject lots. These tests were performed in accordance with ASTM D4829. Test results indicated soils near pad grade have a VERY LOW expansion potential and are summarized in Appendix A. I 1 1 1 [1 1 1 RICHMOND AMERICAN HOMES November 12, 2003 TR 23066-3 Lots 102-114/Temecula Area J.N. 188-01 Page 6 Soluble Sulfate Analyses Soluble sulfate contents were determined for a representative sample of soil existing at or near finish grade within the subject lots. These tests were perfonned in accordance with California Test Method (CTM) No. 417. Test results are provided in Appendix A. Chloride, Resistivity and pH Anal Water-soluble chloride concentration, resistivity and pH values were determined for selected samples in accordance with CTM Nos. 422 (chloride) and 643 (resistivity and pH). The results of these analyses are provided in Appendix A. CONCLUSIONS AND RECOMMENDATIONS Foundation -Design Recommendations Foundation Types Based on as -graded soil and geologic conditions, the use of conventional spread footings with slab -on -grade foundations is considered feasible for the subject lots. Allowable Soil -Bearing Capacities An allowable soil -bearing capacity of 1,500 pounds per square foot (psf) may be used for 24 -inch square pad footings and 12 -inch wide continuous footings founded at a depth of 12 inches or more below the lowest adjacent final grade or top -of -slab. This value may be increased by 20 percent for each additional foot of depth, to a value of 2,500 psf. Recommended allowable soil -bearing values include both dead and live loads and may be increased by one-third when designing for short -duration wind and seismic forces. It 1 2 I RICHMOND AMERICAN HOMES - November 12, 2003 TR 23066-3 Lots 102-114/Temecula Area J.N. 188-01 Page 7 Anticipated Settlement Based on the general settlement characteristics of the compacted fill soils, as well as the anticipated loading, it has been estimated that the total settlement of building footings is anticipated to be less than approximately 3/4 inch. Differential settlement over a horizontal distance of 30 feet is expected to be about one-half the total settlement. The anticipated differential settlement may be expressed as an angular distortion of 1:960. Lateral Resistance A passive earth pressure of 250 psf per foot of depth to a value of up to 2,500 psf may be used to determine lateral -bearing resistance for building footings. Where structures such as masonry block walls and retaining walls are planned on or near descending slopes, the passive earth pressure should be reduced to 150 psf per foot of depth to a value of up to 1,500 psf. An increase of one-third of the above values may also be used when designing for short -duration wind and seismic forces. In addition, a coefficient of friction of 0.40 times the dead -load forces may also be used between concrete and the supporting soils to determine lateral -sliding resistance. The above values are based on footings placed directly against compacted fill or Pauba Formation sandstone. In the case where footing sides are formed, backfill against the footings should be compacted to 90 percent or more of the maximum dry density. Footing Observations Footing trenches should be observed by a representative of Petra to document that they have been excavated into competent -bearing soils and to the recommended embedments. The foundation excavations should be observed prior to the placement of forms, reinforcement or concrete. The excavations should be trimmed neat, level and square. Loose, sloughed or moisture -softened soil and construction debris should a [1 1 RICHMOND AMERICAN HOMES November 12, 2003 TR 23066-3 Lots 102-114/Temecula Area J.N. 188-01 Page 8 be removed prior to placing concrete. Excavated soils derived from footing excavations should not be placed within slab -on -grade areas. Expansive Soil Considerations Laboratory testing of soils within the site indicate soils exhibit VERY LOW expansion potential as classified in accordance with 1997 UBC Table 18-I-13. Very Low Expansion Potential (Expansion Index of 20 or less) The results of our laboratory tests indicate that onsite soils of the subject lots exhibit VERY LOW expansion potential as classified in accordance with 1997 UBC Table 18-I-13. For this condition, it is recommended that footings and floors be constructed and reinforced in accordance with the following criteria. However, additional slab thickness, footing sizes and/or reinforcement may be required by the project architect or structural engineer. • Footines Standard depth footings may be used with respect to building code requirements for the planned construction (i.e., 12 inches deep for one-story construction and 18 inches deep for two stories). Interior continuous footings for one- or two- story construction may be founded at a depth of 12 inches or greater below the top -of -slab. Continuous footings should have a width of 12 and 15 inches or more for one- and two-story buildings, respectively, and should be reinforced with two No. 4 bars, one top and one bottom. - Continuous footings should be reinforced with two No. 4 bars, one top and one bottom and as recommended by the structural engineer. Isolated interior pad footings should be 24 inches or more square and founded at a depth of 12 inches or more below the top -of -slab and reinforced in accordance with the recommendations of the structural engineer. q RICHMOND AMERICAN HOMES November 12, 2003 TR 23066-3 Lots 102-114/Temecula Area J.N. 188-01 Page 9 Isolated exterior pad footings should be 24 inches or more square and founded ' at a depth of 18 inches or more below the lowest adjacent grade and reinforced in accordance with recommendations of the structural engineer. • Floor Slabs - Living -area concrete -floor slabs should be 4 inches or more thick and reinforced with either 6x6-W1.4xW1.4 welded -wire mesh or with No. 3 bars spaced 24 inches on -centers, both ways. Slab reinforcement should be properly supported so that placement is mid -depth. - Living -area concrete floors should be underlain with a moisture -vapor retardant ' consisting of 6 -mil thick polyethylene membrane or equivalent. Two inches or more of clean sand should be placed over the membrane to promote uniform curing of the concrete. ' Garage -floor slabs should be 4 inches or more thick and placed separately from adjacent wall footings with a positive separation maintained with 3/8 inch felt expansion joint materials and quartered with weakened plane joints. A 12 -inch wide grade beam founded at the same depth as adjacent footings should be provided across garage entrances. The grade beam should be reinforced with two No. 4 bars, one top and one bottom and in accordance with the recommendations of the structural engineer. Prior to placing concrete, subgrade soils should be thoroughly moistened to promote uniform curing of the concrete and reduce the development of shrinkage cracks. ' SEISMIC -DESIGN CONSIDERATIONS Ground Motions Structures within the site should be designed and constructed to resist the effects of seismic ground motions as provided in 1997 UBC Sections 1626 through 1633. The method of design is dependent on the seismic zoning, site characteristics, occupancy category, building configuration, type of structural system and on the building height. • L I I I 1 RICHMOND AMERICAN HOMES November 12, 2003 TR 23066-3 Lots 102-114/Temecula Area J.N. 188-01 Page 10 For structural design in accordance with the 1997 UBC, a computer program developed by Thomas F. Blake (UBCSEIS, 1998/1999) was utilized which compiles fault information for a particular site using a modified version of a data file of approximately 150 California faults that were digitized by the California Division of Mines and Geology and the U.S. Geological Survey. This program computes various information for a particular site including the distance of the site from each of the faults in the data file, the estimated slip -rate for each fault and the "maximum moment magnitude" of each fault. The program then selects the closest Type A, Type B and Type C faults from the site and computes the seismic design coefficients for each of the fault types. The program then selects the largest of the computed seismic design coefficients and designates these as the design coefficients for the subject site. Based on the computer generated data using UBCSEIS, the Elsinore -Julian (Type A) segment of the Elsinore fault zone, located approximately 12.1 kilometers west of the site, could generate severe site ground motions with an anticipated maximum moment magnitude of 7.1 and anticipated slip rate of 5.0 mm/year. However, the closest Type B fault, which is the Elsinore -Temecula located approximately 1.3 kilometers to the southwest of Tract 23066-3, would probably generate the most severe site ground motions with an anticipated maximum moment magnitude of 6.8 and anticipated slip rate of 5.0 mm/year. Based on our evaluation using UBCSEIS, the following 1997 UBC seismic design coefficients are recommended for the proposed residential structures. These criteria are based on the soil profile type as determined by existing subsurface geologic conditions, on the proximity of the Elsinore -Temecula fault and on the maximum moment magnitude and slip rate. /f I 11 I 1 [] 11 RICHMOND AMERICAN HOMES TR 23066-3 Lots 102-114/Temecula Area November 12, 2003 J.N. 188-01 Page 11 SOIL CORROSIVITY The corrosion potential of the on-site materials was evaluated for its effect on steel and concrete. The corrosion potential was evaluated using the results of laboratory tests on a representative sample of the near -surface soils. Laboratory testing was performed to evaluate pH, minimum electrical resistivity, and chloride and soluble sulfate content. The test results indicate that the pH of the sample of soil tested was 7.33. A measured electrical resistivity of 2,000 ohm -cm indicated that the site soils may be considered moderately corrosive to ferrous metals. Metal piping should be corrosion protected or consideration should be given to using plastic piping instead of metal. Testing further indicates a soluble sulfate content of 0.003 percent and a chloride content of 170 ppm. We recommend that Type 11 modified cement be used. We further recommend that a 3 -inch thick concrete cover be maintained over the reinforcing steel in concrete in contact with the soil. We recommend that a corrosion engineer be consulted to provide additional recommendations. R 1997 UBC TABLE FACTOR Figure 16-2 Seismic Zone 4 16-1 Seismic Zone Factor Z 0.4 16-U Seismic Source Type B 16-J Soil Profile Type Sp 16-S Near -Source Factor N. 1.3 16-T Near -Source Factor N, 1.6 16-Q Seismic Coefficient C. 0.44 N, = 0.57 16-R Seismic Coefficient C 0.64 N, = 1.02 SOIL CORROSIVITY The corrosion potential of the on-site materials was evaluated for its effect on steel and concrete. The corrosion potential was evaluated using the results of laboratory tests on a representative sample of the near -surface soils. Laboratory testing was performed to evaluate pH, minimum electrical resistivity, and chloride and soluble sulfate content. The test results indicate that the pH of the sample of soil tested was 7.33. A measured electrical resistivity of 2,000 ohm -cm indicated that the site soils may be considered moderately corrosive to ferrous metals. Metal piping should be corrosion protected or consideration should be given to using plastic piping instead of metal. Testing further indicates a soluble sulfate content of 0.003 percent and a chloride content of 170 ppm. We recommend that Type 11 modified cement be used. We further recommend that a 3 -inch thick concrete cover be maintained over the reinforcing steel in concrete in contact with the soil. We recommend that a corrosion engineer be consulted to provide additional recommendations. R I 1 I I I 1 I RICHMOND AMERICAN HOMES November 12, 2003 TR 23066-3 Lots 102-114/Temecula Area J.N. 188-01 Page 12 RETAINING WALLS Retaining walls are not currently proposed within the subject site. The following retaining and masonry wall information is being provided to assist the future homeowners in the event they construct retaining walls within their lots. Footing Embedments The base of retaining -wall footings constructed on level ground may be founded at a depth of 12 or more inches below the lowest adjacent final grade. Where retaining walls are constructed on or within 15 feet from the top of adjacent descending fill slope, the footings should be deepened such that a horizontal setback of H/3 (one-third the slope height) is maintained between the outside bottom edges of the footings and the slope face; however, the footing setback should be 5 feet or more. The above - recommended footing setbacks are preliminary and may require revision based on site- specific soil and/or bedrock conditions. Footing excavations should be observed by the project geotechnical consultant to document that they have been excavated into competent -bearing soils and/or bedrock and to the embedments recommended above. These observations should be performed prior to placing forms or reinforcing steel. Active Earth Pressures An active lateral -earth pressure equivalent to a fluid having a density of 40 pounds per cubic foot (pcf) may be used for design of cantilevered walls retaining a drained, level granular backfill. Where the wall backfill slopes upward at 2:1 (h:v), the above value should be increased to 63 pcf. Retaining walls should be designed to resist surcharge loads imposed by other nearby walls or structures in addition to the above active earth pressures. I 1 I [] 1 I I RICHMOND AMERICAN HOMES November 12, 2003 TR 23066-3 Lots 102-114/Temecula Area J.N. 188-01 Page 13 Drainage A perforated pipe -and -gravel subdrain should be installed behind retaining walls up to 6 feet in height to reduce the likelihood of entrapment of water in the backfill. Perforated pipe should consist of 4 -inch diameter or larger PVC Schedule 40 or ABS SDR -35, with the perforations laid down. The pipe should be embedded in 1.5 cubic feet per foot of 0.75- to 1.5 -inch open -graded gravel wrapped in filter fabric. Filter fabric may consist of Mirafi 140N or equivalent. In lieu of a pipe and gravel subdrain, weepholes or open vertical masonry joints may be considered for retaining walls not exceeding a height of approximately 3 feet. Weepholes, if used, should be 3 inches or more in diameter and provided at intervals of 6 feet or less along the wall. Open vertical masonry joints, if used, should be provided at no more than 32 -inch intervals. A continuous gravel fill, 12 inches by 12 inches, should be placed behind the weepholes or open masonry joints. The gravel should be wrapped in filter fabric to reduce the likelihood of infiltration of fines and subsequent clogging of the gravel. Filter fabric may consist of Mirafi 140N or equivalent. Retaining walls greater than 6 feet high should be provided with a continuous backdrain for the full height of the wall. This drain could consist of a geosynthetic drainage composite, such as Miradrain 6000 or equivalent or a permeable drain material, placed against the entire backside of the wall. If a penneable drain material is used, the backdrain should be 1 or more feet thick. Caltrans Class 1I permeable material or open -graded gravel or crushed stone (described above) may be used as permeable drain material. If gravel or crushed stone is used, it should have less than 5 percent material passing the No. 200 sieve. The drain should be separated from the backfill with a geofabric. The upper 1 foot of the backdrain should be covered with compacted fill. A drainage pipe consisting of 4 -inch diameter perforated pipe I It 1tl I C] L I [1 RICHMOND AMERICAN HOMES November 12, 2003 TR 23066-3 Lots 102-114/Temecula Area J.N. 188-01 Page 14 (described above) should be provided along the back of the wall. The pipe should be placed with perforations down. The drain and pipe should be sloped at 2 percent or more and discharge to an appropriate outlet through a solid pipe. If a geosynthetic drainage composite is used, the perforated pipe should be surrounded by 1 cubic foot per foot of gravel or crushed rock wrapped in a filter fabric. The pipe should outlet away from structures and slopes and the wall should be appropriately waterproofed. The backfilled portions of retaining walls should be coated with an approved waterproofing compound to inhibit migration of moisture through the walls. Temporary Excavations To facilitate retaining -wall construction, temporary excavations greater than 5 feet should be cut back at a gradient of 1:1 (h:v) or flatter for the duration of construction. However, temporary slopes should be observed by the project geotechnical consultant for evidence of potential instability. Depending on the results of these observations, flatter temporary slopes may be recommended. The potential effects of various parameters, such as weather, heavy equipment travel, storage near the tops of the temporary excavations and construction scheduling should also be considered in the stability of temporary slopes. Wall Backfill Retaining -wall backfill should be placed in 6- to 8 -inch loose lifts, watered or air-dried as necessary to achieve near -optimum -moisture conditions and compacted in place to a relative compaction of 90 percent or more as evaluated by ASTM D 1557. W /5 I 1 1 C 11 1 1 1 [I RICHMOND AMERICAN HOMES November 12, 2003 TR 23066-3 Lots 102-114/Temecula Area J.N. 188-01 Page 15 MASONRY BLOCK WALLS Construction on or Near the Tops of Descending Slopes Continuous footings for masonry block walls proposed on or within 7 feet from the top of descending slopes should be deepened such that a horizontal clearance of 5 or more feet is maintained between the outside bottom edge of the footing and the slope face. The footings should be reinforced with two No. 4 bars, one top and one bottom for Very Low expansion soils and in accordance with the recommendations provided by structural engineer. Plans for top -of -slope block walls proposing pier and grade -beam footings should be reviewed by Petra prior to construction. Construction on Level Ground Where masonry block walls are proposed on level ground and 5 feet or more from the tops of descending slopes, the footings for these walls may be founded at depth of 12 or more inches below the lowest adjacent final grade. These footings should also be reinforced with two No. 4 bars, one top and one bottom for Very Low expansion soils and in accordance with the recommendations of the structural engineer. Construction Joints In order to mitigate the potential for unsightly cracking related to the effects of differential settlement, positive separations (construction joints) should be provided in the walls at horizontal intervals of approximately 25 feet and at each comer. The separations should be provided in the blocks only and not extend through the footings. The footings should be placed monolithically with continuous rebars to serve as effective "grade beams" along the full lengths of the walls. a [1 1 1 1 I RICHMOND AMERICAN HOMES November 12, 2003 TR 23066-3 Lots 102-114/Temecula Area J.N. 188-01 Page 16 CONCRETE FLATWORK Thickness and Joint Spacing Concrete sidewalks and patio -type slabs should be 4 inches or more thick and provided with construction joints every 6 feet or less. Concrete -driveway slabs should be 4 inches or more thick and provided with construction joints quartering the slab, but no more than 10 feet apart. Subgrade Preparation As a further measure to reduce cracking of concrete flatwork, the subgrade soils below concrete- fl atwork areas should first be compacted to a relative density of 90 percent or more, as evaluated by ASTM D1557. Water should be added then to achieve a moisture content that is equal to or slightly greater than optimum moisture content. This moisture should extend to a depth of 12 inches below subgrade and maintained in the soils during placement of concrete. Pre -watering of the soils will promote uniform curing of the concrete and reduce the development of shrinkage cracks. A representative of the project soils engineer should observe and document the density and moisture content of the soils and the depth of moisture penetration prior to placing concrete. PLANTERS Area drains should be extended into planters that are located within 5 feet of building walls, foundations, retaining walls and masonry block garden walls to reduce infiltration of water into the adjacent foundation soils. The surface of the ground in these areas should also be sloped at a gradient of 2 percent or more away from the walls and foundations. Drip -irrigation systems are also recommended to reduce the likelihood of overwatering and subsequent saturation of the adjacent foundation soils. /7 I 1 I [1 1 [1 RICHMOND AMERICAN HOMES November 12, 2003 TR 23066-3 Lots 102-114/Temecula Area J.N. 188-01 Page 17 UTILITY TRENCHES Utility -trench backfill within street right-of-ways, utility easements, under sidewalks, driveways and building -floor slabs, as well as within or in proximity to slopes should be compacted to a relative density of 90 percent or more as evaluated by ASTM D1557. Soils utilized as backfill should be mechanically compacted. Density testing, along with probing, should be performed by the project soils engineer or his representative, to document proper compaction. For trenches with vertical walls, backfill should be placed in approximately 1- to 2 - foot thick loose lifts and then mechanically compacted with a hydra -hammer, pneumatic tampers or similar equipment. For trenches with sloped -walls, backfill materials should be placed in approximately 8- to 12 -inch thick loose lifts and then compacted by rolling with a sheepsfoot tamper or similar equipment. To avoid point -loads and subsequent distress to clay, cement or plastic pipe, imported sand bedding should be placed 1 foot or more above pipe in areas where excavated trench materials contain significant cobbles. Bedding materials should be mechanically compacted to 90 percent or more relative compaction as evaluated by ASTM D1557 and tested. Flooding of sand bedding should not be allowed. Where utility trenches are proposed parallel to building footings (interior and/or exterior trenches), the bottom of the trench should not be located within a 1:1 (h:v) plane projected downward from the outside bottom edge of the adjacent footing. SLOPE LANDSCAPING AND MAINTENANCE The engineered slopes within the subject tract are considered grossly and surficially stable and are expected to remain so under normal conditions provided the slopes are IT I 1 1 1 1 RICHMOND AMERICAN HOMES November 12, 2003 TR 23066-3 Lots 102-114/Temecula Area J.N. 188-01 Page 18 landscaped and maintained thereafter in accordance with the following recommendations. • Compacted -earth berms should be constructed along the tops of the engineered fill slopes, as well as natural slopes, to reduce the likelihood of water from flowing directly onto the slope surfaces. • The engineered cut and fill slopes should be landscaped as soon as practical when irrigation water is available. The landscaping should consist of deep-rooted, drought -tolerant and maintenance -free plant species. A landscape architect should be consulted to determine suitable groundcover. If landscaping cannot be provided within a reasonable period of time, jute matting (or equivalent) or a spray -on product designed to seal slope surfaces should be considered as a temporary measure to reduce surface erosion until such a time that permanent landscape plants have become well-established. • Irrigation systems should be installed on the engineered slopes and a watering program then implemented which maintains a uniform, near -optimum moisture condition in the soils. Overwatering and subsequent saturation of the slope soils should be avoided. On the other hand, allowing the soils to dry -out is also detrimental to slope performance. • Irrigation systems should be constructed at the surface only. Construction of sprinkler lines in trenches is not recommended. • During construction of terrace drains, downdrains or earth berms, care should be taken to avoid placement of loose soil on the slope surfaces. • A permanent slope -maintenance program should be initiated for major slopes not maintained by individual homeowners. Proper slope maintenance should include the care of drainage and erosion -control provisions, rodent control and repair of leaking or damaged irrigation systems. • Provided the above recommendations are followed with respect to slope drainage, maintenance and landscaping, the potential for deep saturation of slope soils is considered low. • Property owners should be advised of the potential problems that can develop when drainage on the building pads and adjacent slopes are altered. Drainage can be 19 I 1 H RICHMOND AMERICAN HOMES November 12, 2003 TR 23066-3 Lots 102-114/Temecula Area J.N. 188-01 Page 19 altered due to the placement of fill and construction of garden walls, retaining walls, walkways, patios, swimming pools, spas and planters. POST -GRADING OBSERVATIONS AND TESTING Petra should be notified at the appropriate times in order that we may provide the following observation and testing services during the various phases of post grading construction. • Building Construction - Observe footing trenches when first excavated to document specified depth and competent soil -bearing conditions. - Observe moisture conditioning of subgrade soils below living -area and garage floor slabs to document moisture content and penetration. • Retaining -Wall Construction - Observe footing trenches when first excavated to document specified depth and competent soil -bearing conditions. - Observe and document proper installation of backdrain systems prior to placing wall backfill. - Observe and test placement of wall backfill to document specified compaction. ' Masonry Block -Wall Construction Observe footing trenches when first excavated to document depth and presence of competent soil -bearing conditions. • Exterior Concrete-FlatworkConstruction ' Observe and test subgrade soils below concrete-flatwork areas to document compaction and moisture content. I I I I I 1 [1 I I RICHMOND AMERICAN HOMES November 12, 2003 TR 23066-3 Lots 102-114/Temecula Area J.N. 188-01 Page 20 • Utility -Trench Backfill - Observe and test placement of utility -trench backfill to document specified ,compaction. • Re-Gradine Observe and test placement of fill to be placed above or beyond the grades shown on the approved grading plans. This opportunity to be of service is sincerely appreciated. If you have questions, please contact this office. Respectfully submitted, Cliff Cry Principal Engin WC/RLG/CAC/keb �QgOFESS/pv 4Q�o v0 AtF,y q�F z No. GE000Z43 ti m Expl,�,�� OF CALIF Attachments: Figure 1 - Geotechnical Map with Density Test Locations Table I - Lot -By -Lot Summary of As -Graded Soil Conditions Table II - Field Density Test Results References Appendix A - Laboratory Test Criteria/Laboratory Test Data Distribution: (1) Addressee (3) Richmond American Homes Attention: Ms. Theresa Johnson (1) Richmond American Homes - Field Office Attention: Mr. Craig Peters (2) Riverside County Building and Safety Attention: Mr. Mack Hakakian (1) Hunsaker & Associates Attention: Mr. Dan Hosseninvadeh (1) Option One Consulting Attention: Mr. Ross Kuster W I/ [] 1 1 I 1 1 X00 �-- ♦I 6 OHO ro OHO a � -�-_ � `L o. • ,LOO -. 1 ■ w ■ al OD`tK L 4� `)O'l000 o� DSD` DO jY. 1 1 !r Q 1 r 0�0 l '` gP-�-T `,� `foo" 1�L � ooh 001 r _i ,- -! 32 NV -1%r ` tK '`0�`l• t�0 hQ��00�Q tLQ��Qn�9�6 N �� 0001 nj� �■ 1 L.,k v -tea 1 � �.mien.N f REFERENCE: HUNSAKER & ASSOCIATES, ROUGH GRADING PLAN, COUNTY OF RIVERSIDE TRACT NUMBERS 23066-1, 23066-1, 23066-3, AND 23066, SHEET 12 OF 13, DATED 1/01. EXPLANATION (LOCATIONS ARE APPROXIMATE) afc ARTIFICIAL FILL, COMPACTED Qps QUATERNARY PAUBA FORMATION SANDSTONE �GEOLOGIC CONTACT ® 2084 DENSITY TEST LOCATION 1200.1 INDICATES REMOVAL DEPTH ELEVATION IN FEET 0011®0001■m■m■omi■ SUBDRAIN WITH 1170.0 REMOVAL DEPTH ELEVATION IN FEET %oro Scale 0 40 Feet GEOTECHNICAL MAP WITH DENSITY TEST LOCATIONS TRACT 23066-3, LOTS 102 THROUGH 114 PETRA GEOTECHNICAL, INC. JN 188-01 NOV, 2003 FIGURE 1 as TABLE I Tract 23063-3 Lots 102 through 114 LOT -BY -LOT SUMMARY OF SOIL CONDITIONS Lot -Number Maximum Fill Depth (ft) Minimum Fill Thickness ft) Estimated Differential Settlement Soil Expansion Index/Potential Post -Tensioned Slab Soil Condition Codes* Remarks 102 43 13 1:960 4/V Low optional Z 103 42 13 1:960 4/V Low optional Z 104 44 14 1:960 4/V Low optional Z 105 44 14 1:960 4/V Low optional Z 106 44 25 1:960 0/V Low optional Z 107 44 37 1:960 0/V Low optional Z 108 45 30 1:960 0/V Low optional Z 109 35 25 1:960 0/V Low optional Z 110 25 10 1:960 0/V Low optional Z 111 10 7 1:960 0/V Low optional Z 112 21 10 1:960 0/V Low optional Z 113 25 10 1:960 0/V Low optional Z 114 25 10 1:960 0/V Low optional Z ' per County of Riverside, Building and Safety Department Plan Check Memorandum dated April 5, 2001 Code Definitions (Reference. 1997 UBC): E Foundations for structures resting on soils with an expansion index greater than 20 (Section 1803.2) C For corrosion protection, if Table 19-A-2 is applicable S If exposure of concrete to sulfate -containing solutions is moderate or higher per Table 19-A-4 D Differential deflection in the foundation due to differential settlement exceeds value in Table 18 -111 -GG (consider Prefab Roof "frusses) [noted rf>]: 480] P If post -tensioned slab system is to be used Z If none of the above is applicable 9.% k-04 Plate T-1 1 ITABLE 11 Field Density Test Results 05/23/02 1153 Lot 107 1155.0 11.8 119.4 Al l N� 85/28/02 1195 Lot 106 1258.0 16 124.0 95 9 ~~ 05/28/02 1209 Lot 106 1178.0 13.8 121.6 91 ]l 05/28/02 1210 Lot 106 1179.0 14.0 117.1 Vl 4 05/28/02 1213 Lot 105 1182.0 13.1 1159 90 4 05/28/02 1214 Lot 105 11830 116 119.4 Yl 9 05/31/02 1257 Lot 107 1160.0 139 1147 90 3 06/03/02 1260 Lot 107 1161.0 7.9 1139 90** 12 06/03/02 1261 Lot 107 1162A 97 1116 89** 10 06/02/02 1263 RTNo. l26A - 119 1202 95** 12 06/03/02 1264 xTNo. l26l - 99 120.5 95** 12 06/03/02 1265 Lot 107 1169.0 86 1157 91 ] 06/03/02 1266 Lot 107 1170.0 86 1172 93 12 wm 06/04/02 1313 Lot 107 1170.0 9.8 119.2 91 9 06/04/02 1314 Lot 107 1171.0 136 114.8 92 10 N� � 06/04/02 1317 Lot l08 1175.0 12.1 112.9 91 10 06/04/02 1318 Lot 108 1176.0 102 107j 89 8 06/04/02 1319 Lot 105 1184.0 119 1066 92 5 06/04/02 1320 Lot 105 1185.0 6.8 110.5 92 8 06/04/02 1324 Lot 107 1181.0 107 114.1 90 12 06/04/02 1325 KT No. 1318 - 124 1087 90 8 06/04/02 1328 Lot 106 1179.0 14.1 1126 YV 10 06/04/02 1329 Lot 106 1180.0 13.0 113.5 91 lA 06/04/02 1330 DT No. 1321 - 154 108.6 90 S N� 06J04/02 1331 Lot 108 11710 11.8 1153 91 12 06/05/02 1336 Lot 104 11858 10.6 115.0 92 10 � 06/0�/02 1337 Lot 104 ll86�V 7.8 - 118.2 92 4 mm 06/05/02 1338 Lot 103 11888 10.0 112.8 91 10 06/05/02 1339 Lot 103 11810 97 119.8 92 9 N� 06/A�/02 l�53 Lot ll85�A 12.6 120.2 92 9 06/05/02 1354 Lot 107 1186/0 104 121.9 91 ll 06/06/02 1370 Lot 106 1192.0 10.1 118.2 92 4 N� 06/06/02 1371 Lot 106 1193.0 12.5 1139 90 12 06/06/02 1378 Lot 105 1191.0 77 1217 90 ll 06/06/02 1379 Lot 105 1192.0 11.6 1110 92 ll 06/06/02 1380 Lot 108 1189.0 10.4 116.8 92 12 06/06/02 1381 Lot 108 1190.0 11.8 1147 91 12 06/07/02 1384 Lot 106 1106.0 13.1 112.1 90 10 06/07/02 1385 Lot 106 1187.0 11.0 111.5 91 12 06/07/02 1388 Lot 104 1190 .0 15.0 116 .3 90 4 0� 06/07/02 1389 Lot 104 1191.0 8.6 110.9 89 10 �= 06/07/02 1399 }<INo. \389 - llJ 1136 91 10 PETRA GEOTECHNICAL, INC. NOVEMBER 2003 J.N.18D^D1 TR 23066^3/Lmts102^114 TABLE.111 r TABLE II Field Density Test Results BATE NO. LOCATIL?N (ft) i°f°} (pef) : (°f°) iYPT 1413 Lot 106 1184.0 12.5 117.9 90 9 '06/07/02 06/07/02 1414 Lot 106 1185.0 12.8 118.4 91 9 06/10/02 1439 Lot 107 1193.0 8.7 113.0 89 12 1440 Lot 107 1192.0 5.8 112.9 88 4 '06/10/02 06/10/02 1442 RT No. 1439 10.6 113.4 91 10 06/10/02 1444 RT No. 1440 -- 11.3 115.8 90 4 '06/10/02 1451 Lot 104 1193.0 14.0 118.1 90 9 06/10/02 1452 Lot 104 1194.0 9.7 125.7 94 11 06/10/02 1455 Lot 107 1192.0 8.7 117.2 91 4 06/10/02 1456 Lot 107 1191.0 12.5 112.3 90 10 06/10/02 1457 Lot 108 1193.0 10.6 112.4 90 10 06/10/02 1458 Lot 108 1194.0 11.1 113.4 91 10 06/10/02 1461 Lot 106 1196.0 9.1 113.8 91 10 06/10/02 1462 Lot 106 1197.0 9.2 109.7 88 10 1463 Lot 102 1192.0 10.5 120.1 92 9 '06/10/02 06/10/02 1464 Lot 102 1193.0 8.9 121.4 91 11 06/11/02 1471 Lot 105 1195.0 13.5 117.9 92 4 1472 Lot 105 1196.0 13.3 119.9 90 7 '06/11/02 06/11/02 1473 RT No. 1462 12.1 116.7 91 4 06/11/02 1478 Lot 106 1191.0 9.6 120.0 92 9 06/11/02 1479 Lot 105 1191.0 10.9 117.4 90 9 06/11/02 1480 Lot 104 1190.0 10.2 120.1 92 9 06/11/02 1481 Lot 103 1192.0 11.6 119.8 92* 9 06/11/02 1504 Lot,102 1195.0 12.4 120.4 93 4 06/11/02 1505 Lot 102 1196.0 11.8 114.5 91 12 06/12/02 1514 Lot 108 1199.0 11.3 114.6 90 12 06/12/02 1515 Lot 107 1198.0 11.4 114.6 90 12 06/12/02 1516 Lot 105 1200.0 9.3 119.8 92 9 06/12/02 1519 Lot 104 1199.0 8.4 119.8 91 9 06/12/02 1520 Lot 109 1199.0 11.0 119.2 91* 9 06/12/02 1522 Lot 106 1200.0 12.5 114.8 90 12 ' 06/13/02 1553 Lot 103 1193.0 10.1 117.3 90 9 06/13/02 1554 Lot 104 1192.0 11.2 118.5 91 9 06/13/02 1555 Lot 105 1193.0 12.5 118.1 90 9 ' 06/13/02 1556 Lot 106 1194.0 11.1 119.5 91* 9 06/13/02 1559 Lot 108 1199.0 11.6 116.7 87 11 06/13/02 1560 RTNo. 1559 -- 11.3 120.0 90 11 06/13/02 1561 Lot 109 1201.0 12.0 116.6 87 11 06/13/02 1562 RT No. 1561 -- 10.8 119.7 90 11 06/14/02 1563 Lot 105 1195.0 11.6 117.6 90 9 06/14/02 1564 Lot 106 1196.0 10.9 119.4 91* 9 06/14/02 1565 Lot 107 1196.0 11.4 119.4 91 9 PETRA GEOTECHNICAL, INC. NOVEMBER 2003 J.N. 188-01 TR 23066-3/1-ots 102-114, TABLE -II 2 IField Density Test Results 06/14/02 1566 Lot 104 1195.0 11.1 120.0 92 9 N� U6/l7/02 1644 Lot 103 1212.0 11.3 118.3 90 9 06/17/02 1646 Lot 106 1210.0 10J 118j 90 9 06/17/02 1647 Lot 105 1I10.0 10.0 1194 92 9 N� 06/17/02 1648 Lot 109 1208.0 11.0 118.5 91 Y 06/17/02 1649 Lot 110 1208.0 11.4 119.0 91 9 06/17/02 1650 Lot 111 1208.0 11.3 1182 90 v 00 07/24/02 1909 Lot l0yfiuiobslope 1213.0 18.6 100.6 92 6 07/24/02 1910 Lot lO9finish slope 1207.0 9.0 112.4 90 10 03/11/03 2015 Lot 106 1209.0 11.0 116.5 91* ] 03/11/03 2016 Lot 104 1208.0 10.9 116.1 Al 3 03/11/03 2017 Lot 102 1209.0 11.2 1154 90 3 0� 03/11/03 2018 Ln1ll]olopo 1172.0 10.3 119.9 91 ll ow 01/11/03 2019 Lotll3oloye 1173.0 10.6 119.5 90 ll 03/12/03 2020 Lot lllslope 1174.0 10.3 119.0 90 ll N� 03/12/03 2021 Lot l|4slope 1174.0 10.5 120.1 91 11 -- 03/12/03 2022 Lot 105 1210 .0 11 .2 118 .7 VV ll 03/12/03 2023 Lot 103 1211.0 18.8 119.4 90 ll N� 03/12/03 2024 Lot 106 1211.0 11.4 118.5 90 ll 03/12/03 2025 Lot 104 1212 .0 ll.0 120 .4 Vl l) 03/12/03 2026 Lot ll2slope 1175.0 10.3 l}V.K 91 ll 03/12/03 2027 Lot l\4slope 1176.0 10.0 120.8 92 )l 03/13/03 2028 Lot 102 1212.0 10.2 119.3 90* ll 02/13/03 2029 Lot 107 , 1213.0 11.1 117.1 89 ll N� 03/13/03 2030 llTNo. 202V '' 10.8 118.6 90 li 03/14/02 2033 Lot 108 1209.0 11.0 114.6 90 3 0� 02/14/03 2034 Lot 113 slope 1177.0 ll. 5 116.3 . 91 l 03/14/03 2035 Lot ll4slope 1180.0 llJ 1152 90 ] 03/14/03 2036 Lot \|3slope 1179.0 10J 115.4 Vl 3 N� 03/14/03 2037 lot ll2slope 1180.0 10.9 116.0 91 3 03/19/03 2038 Lot ll3slope 11820 10j 1173 92 l� 03/19/03 2039 Lot ll4slope 1184.0 10J 115.1 vl 13 N� 03/19/03 2040 Lot 112 1186U 11.0 115.0 yl 13 03/19/03 2041 I.otll4olupo 1187.0 lO7 118.69O l2 03/19/03 2042 � Lot 11'3 ll880 . 4� . ll8 .4 90 12 03/19/03 2042 Lot ll]slope 11888 9.9 119.2 90* 12 03/19/03 2044 Lot 113 1189.0 10.4 1166 02 13 03/20/03 2045 Lot ll2slope 1191.0 11.3 118.9 90 ll m� 03/20/03 2046 Lot ll2slope 1193.0 10.9 110.1 90 ll 03/20/03 2047 Lot ll4slope 1194.0 107 1I1.3 92 ll N� 03/20K03 2048 Lot ll2olo�t 1196.0 11.0 118.4 90 ll 03/20/03 2049 Lot 112 1195.0 10.5 120.8 91 ll PETRA GEOTECHNICAL, INC. NOVEMBER 2003 J.N. 188~01 TR 23066^3/Lots102`114 TABLE^113 ' TABLE 11 ' Field Density Test Results DATE NO. I bCATION (rij {°fa} {pcfl; {°�oj Tyra 03/21/03 2050 Lot 114 1197.0 10.0 121.3 92 11 03/21/03 2051 Lot 111 1198.0 10.7 119.6 91 11 03/21/03 2053 Lot 112 1200.0 9.5 120.1 91 12 2054 Lot 111 1200.0 11.5 119.7 91 11 '03/22/03 03/22/03 2055 Lot 113 1201.0 12.3 118.3 90 11 03/22/03 2057 Lot 114 1201.0 11.6 119.2 90 11 '03/24/03 2058 Lot 110 1207.0 9.9 119.8 91 12 03/24/03 2059 Lot 112 1202.0 9.5 118.7 90 12 2060 Lot 114 1202.0 8.9 120.2 91 12 '03/24/03 03/25/03 2065 Lot 109 1208.0 11.8 116.3 91* 3 03/25/03 2067 Lot 114 1204.0 10.3 120.4 91 11 03/26/03 2068 Lot 112 1204.0 10.0 119.8 91 11 1 03/26/03 2069 Lot 113 1206.0 10.5 119.0 90 11 03/26/03 2070 Lot 114 1206.0 11.2 118.4 90 11 03/26/03 2072 Lot Ill 1209.0 10.0 121.2 92 11 03/26/03 2074 Lot 110 1209.0 10.0 119.9 91 11 03/27/03 2075 Lot 109 slope 1210.0 10.3 121.2 92 11 03/27/03 2076 Lot 111 slope 1210.0 11.0 118.5 90 11 03/27/03 2077 Lot 113 slope 1209.0. 10.5 118.9 90 11 03/28/03 2079 Lot 108 slope -berm 1211.0 10.2 120.3 91 11 03/28/03 2080 Lot 110 slope 1214.0 11.3 118.9 90 11 03/28/03 2081 Lot 107 slope 1212.0 10.0 121.6 92 11 03/31/03 2082 Yucca St/Sta 30+50 1210.0 8.5 120.2 91 12 ' 03/31/03 2084 Yucca St/Sta 29+10, 1208.0 9.3 118.4 90 12 03/31/03 2085 Lot 112 1211.0 8.0 122.1 92 12 04/04/03 2114 Lots 111-115 slope 1184.0 11.2 118.3 90 11 04/04/03 2115 Lots 111-115 slope 1205.0 11.0 118.7 90 11 07/10/03 2123C Yucca St/Lot 114 adj 1211.0 9.3 1183 92 3 07/10/03 2124A Yucca St/Lot 112 adj 1212.0 9.6 119.4 93 3 07/10/03 2125A Yucca St/Lot 110 adj 1213.0 9.5 119.3 93 3 07/10/03 2126A Yucca St/Lot 108 adj 1208.0 9.3 119.2 93 3 07/10/03 2128A Yucca St/Lot 113 adj 1212.0 9.3 118.4 92 3 ' 07/10/03 2129A Yucca St/Lot 111 adj 1213.0 9.4 118.3 92 3 07/10/03 2131A Yucca St/Lot 103 adj 1210.0 8.7 117.7 92 3 07/10/03 2132A Yucca St/Lot 105 adj 1211.0 9.5 117.5 92 3 07/10/03 2133A Yucca St/Lot 107 adj 1212.0 9.4 118.3 92 3 07/10/03 2134A Yucca St/Lot 102 adj 1212.0 8.7 116.9 91 3 07/10/03 1 2135A Yucca St/Lot 104 adj 1212.0 8.9 116.0 90 3 07/10/03 2136A Yucca St/Lot 106 addjj 1214.0 9.4 117.0 91 3 PETRA GEOTECHNICAL, INC. NOVEMBER 2003 J.N. 188-01 TR 23066-3/Lots 102-114. TABLE -11 4 a7 I REFERENCES Blake, T.F., 1998/1999, "UBCSEIS" Version 1.03, A Computer Program for the Estimation of Uniform Building Code Coefficients Using 3-D Fault Sources. ' International Conference of Building Officials, 1997, Uniform Building Code, Volume 2, Structural Engineering Design Provisions, dated April. ' Earth Research Associates, Inc., 1987, Evaluation of Faulting and Liquefaction Potential, Portion of Wolf Valley Project, Rancho California, County of Riverside, California, J.N. 298-87, dated November 20. ' 1988, Preliminary Soils Engineering and Engineering Geologic Investigation, Red Hawk Project, Rancho California Area, County of Riverside, California, J.N. 298-87, dated February 2. ' Kennedy, M.P., 1977, Recency and Character of Faulting Along the Elsinore Fault Zone in Southern Riverside County, California, CDMG Special Report 131. Petra Geotechnical, Inc., 1989, Supplemental Soils Engineering and Engineering Geologic Investigation, Portion of Redhawk Project, Vesting Tentative Tract Map Nos. 23064, 23065, 23066 and 23067, Rancho California, County of Riverside, California, Volumes I and IJ, J.N. 298-87, dated May 8. ' , 2001 a, Due -Diligence Geotechnical Assessment of Planned Grading and Site Development, Tracts 23066-1, 23066-2 and 23066-3, Redhawk Development, Temecula Area, Riverside County, California, J.N. 188-01, dated March 30. ' , 200 lb, Supplemental Geotechnical Investigation, Tract 23066-3, Lot 129, Redhawk Development, Temecula Area, Riverside County, California, J.N. 188-01, dated April, 18. ' , 2001c, Response to Riverside County Geotechnical Report Review Sheet Dated April 24, 2001, Tracts 23066-1, 23066-2 and 23066-3, Redhawk Development, Temecula Area, Riverside County, California; for The Garrett Group LLC, J.N. 188-01, dated December 11. ' , 2001 d, Documentation of Previous Interface Grading Adjacent to Golf Course Fairways, Tracts 23066-1, 23066-2 and 23066-3, Temecula Area of Riverside County, California, J.N. 188-01, dated December 10. ' 2001 e, Geotechnical Review of 40 -Scale Rough Grading Plans, Tracts 23066, 23066-1, 23066-2 and 23066-3, Temecula Area of Riverside County, California, dated December 11. ' , 2002a, Geotechnical Recommendations Regarding Expansive Soils, Tracts 23066-1, 23066-2, 23066-3 and 30246, Temecula Area, Riverside County, California, J.N. 188-01, dated March 20. t , 2002b, Response to Riverside County Building and Safety Department Geotechnical Report Review Sheet, Dated February 21, 2002 and Grading Plan Review Report, Tract 30246, Temecula Area, Riverside County, California, BGR No. 020159, J.N. 188-01, dated March 21. ' , 2002c, Geotechnical Design Parameters for Medium Expansive Soils, Tracts 23066-1, 23066-2, 23066-3 and 30246, Temecula Area, Riverside County, California, J.N. 188-01, dated March 26. ' PETRA GEOTECHNICAL, INC. NOVEMBER 2003 ' J.N. 188-01 J'� I REFERENCES (Continued) , 2002d, Preliminary Geotechnical Recommendations Regarding Expansive Soils, Model Lots, Tract 23066-1, Lots 3 through 5, Temecula Area, Riverside County, California, J.N. 188-01, dated April 3. , 2002e, Preliminary Geotechnical Recommendations Regarding Expansive Soils, Phase I, Tract 23066-2, Lots 10 through 39, Temecula Area, Riverside County, California, J.N. 188-01, dated April 3. , 2002f, Geotechnical Recommendations, Post -Tensioned Slabs, Tracts 23066-1, 23066-2, 23066-3 and 30246, Temecula Area, Riverside County, California, J.N. 188-01, dated April 9. , 2002g, Geotechnical Report of Rough Grading, Model Lots 1 through 8, Tract 23066-2, Temecula Area, Riverside County, California, J.N. 188-01, dated April 26. 2002h, Geotechnical Report of Rough Grading, Lots 9 through 39, Tract 23066-2, City of Temecula, Riverside County, California, J.N. 188-01, dated May 8. , 2002i, Geotechnical Report of Rough Grading, Model Lots 92 through 95, Tract 23066-1, City of Temecula, Riverside County, California, J.N. 188-01, dated May 30. , 2002j, Geotechnical Report of Rough Grading, Lots 54 through 77 and 115, Tract 23066-1, City of Temecula, Riverside County, California, J.N. 188-01, dated June 20. , 2002k, Geotechnical Report of Rough Grading, Lots 40 through 82, Tract 23066-2, City of Temecula, Riverside County, California, J.N. 188-01, dated August 13. , 20021, Geotechnical Report of Rough Grading, Lots 39 through 95, Tract 23066-2, City of Temecula, Riverside County, California, J.N. 188-01, dated August 27. , 2003a, Geotechnical Report of Rough Grading, Lots 27 through 38, Tract 23066-3, Temecula Area, Riverside County, California, J.N. 188-01, dated April 15. 2003b, Geotechnical Report of Rough Grading, Lots 18 through 26 and 96 through 98, Tract 23066-3, Temecula Area, Riverside County, California, J.N. 188-01, dated June 25. , 2003c, Geotechnical Report of Rough Grading, Lots 16, 17, 99 through 101 and 115 through 121, Tract 23066-3, Temecula Area, Riverside County, California, J.N. 188-01, dated August 25. , 2003d, Geotechnical Report of Rough Grading, Lots 122 through 129 (Phase 11), Tract 23066-3, Temecula Area, Riverside County, California, J.N. 188-01, dated October 24. PETRA GEOTECHNICAL, INC. NOVEMBER 2003 J.N. 188-01 APPENDIX A LABORATORY TEST CRITERIA LABORATORY TEST DATA PETRA 30 I 1 1 APPENDIX A LABORATORY TEST CRITERIA Laboratory. Maximum Dry Density Maximum dry density and optimum moisture content were determined for selected samples of soil in accordance with ASTM Test Method D1557. Pertinent test values are presented on Plate A-1. Expansion Index Expansion index tests were performed on selected samples of soil in accordance with ASTM Test Method D4829. Expansion potential classifications were detetnuned from 1997 UBC Table 18 -I -B on the basis of the expansion index values. Test results and expansion potentials are presented on Plate A-1. Corrosion Tests Chemical analyses were performed on selected samples of onsite soil to determine concentrations of soluble sulfate and chloride, as well as pH and resistivity. These tests were performed in accordance with California Test Method Nos. 417 (sulfate), 422 (chloride) and 643 (pH and resistivity). Test results are included on Plate A-1. Soluble Sulfate Chemical analysis was performed on a selected sample of onsite soil to determine concentrations of soluble sulfate. This test was performed in accordance with California Test Method No. 417. The test result is included on Plate A-2. PETRA GEOTECHNICAL, INC. NOVEMBER 2003 J.N. 188-01 LABORATORY MAXIMUM DRY DENSITY Sample TAP y �¢�MIR T�*'SoW 3 Y g2k xm 4 a umum� I Dark brown Clayey Silty fine SAND 8.5 131.5 2 Light brown Silty SAND 8.0 133.5 3 Brown Clayey fine SAND 10.5 127.5 1 4 Light brown Silty, Clayey fine- to medium -grained SAND 10.0 128.5 5 Light brown very fine Sandy SILT 14.0 116.0 6 Yellow brown fine SAND 13.0 109.0 7 Yellowish light brown fine to course SAND with Clay and Gravel 8.5 132.0 8 Yellowish light brown fine to medium SAND with trace Clay and Silt 12.5 120.5 9 Light brown Silty SAND with trace Clay 8.5 130.5 10 Medium brown Clayey SILT 11.5 124.5 11 Medium brown Clayey medium to coarse SAND with cobbles 8.0 133.5 12 Light brown Silty to Clayey fine SAND 10.5 126.5 13 Brown I Silty SAND 10.0 132.0 J EXPANSION INDEX TEST DATA Sam 16LIWNo��.Fk��Z WWII&M0 i ;iresentative, Lots k, �5 mx - Mh MN 8 �4 -a?" M: 5 104 102 through 105 4 Very Low 106 106 through 108 0 Very Low 110 109 through 112 0 Very Low 114 113 and 114 0 Ver Low (1) PER ASTM D1557 (2) PER ASTM D4829 (3) PER 1997 UBC TABLE 18-1-B, CORROSION TESTS PETRA GEOTECHNICAL, INC. NOVEMBER 2003 I.N. 188-01 Plate A-1 -3�L I LotlNumber,"�� Sulfate ..� rt Chlorlde� � � �-pH ,� Reslstrvrty x Corroslvlty,�, 110 0.0030 170 7.33 2,000 concrete: negligible steel: moderate ' (4) PER CALIFORNIA TEST METHOD NO. 417 (5) PER CALIFORNIA TEST METHOD NO. 422 ' (6) PER CALIFORNIA TEST METHOD NO. 643 (7) PER CALIFORNIA TEST METHOD NO. 643 1 1 PETRA GEOTECHNICAL, INC. NOVEMBER 2003 ' 1. N. 188-01 Plate A-2 33