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HomeMy WebLinkAboutInterim Geotechnical Rpt Lots 18-26, 96-98PETRA OFFICES THROUGHOUT SOUTHERN CALIFORNIA June 25, 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: Interim Geotechnical Report of Rough Grading, Lots 18 through 26, and 96 through 98, Tract 23066-3, Temecula Area, Riverside County, California This interim report presents a summary of the observation and testing services provided by Petra Geotechnical, Inc. (Petra) during rough -grading of Lots 18 through 26 and 96 through 98 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. Preliminary rough -grading within the golf-course/tract interface was performed within the subject tract from 1989 through 1990 under the purview of Petra. 'Petra reported on the interface grading in a report issued in December 2001 (see References). REGULATORY COMPLIANCE Cuts, removals and compaction of unsuitable low-density surface soils, lot overexcavations 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 PETRA GEOTECHNICAL, INC. 41640 Corning Place . Suite 107 . Murrieta . CA 92562 . Tel: (909) 600-9271 . Fax: (909) 600-9215 RICHMOND AMERICAN HOMES June 25, 2003 TR 23066-3 Lots 18-26 & 96-98/Temecula Area J.N. 188-01 Page 2 previous 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 laboratory testing, the recommendations presented in this report were prepared in conformance with generally accepted professional engineering practices and no further warranty is implied nor made. SUMMARY OF AS -GRADED SOIL AND GEOLOGIC CONDITIONS As -Graded Conditions and Remedial Grading Remedial grading during the 1989 and 1990 interface grading generally involved the removal and replacement as compacted fill of low-density surfrcial soils that included alluvium and colluvium which may be subject to hydrocollapse or consolidation, as well as near -surface weathered bedrock materials. Remedial grading of the site at that time also consisted of removal and compaction of soils within haul roads and loose end -dumped fill piles. Remedial grading during the recent phase of rough grading included similar removals plus surficial overexcavation on the order of 2 to 8 feet deep and compaction. Recent remedial grading also included overexcavation of the cut portions of cut/fill transition lots. The compacted fills ranged in thickness from approximately 3 to 7.5 feet. A lot - by -lot summary of the compacted -fill depths and a summary of soil conditions is presented in the attached Table 1. A general description of the soil and bedrock materials underlying the subject tract is provided below. • Artificial Fill (mQ symbol afc) —The compacted -fill soils placed in 1989 through 1998 consisted generally of silty sand and sandy silt with variable clay. The 3 I RICHMOND AMERICAN HOMES June 25, 2003 TR 23066-3 Lots 18-26 & 96-98/Temecula Area J.N. 188-01 ' Page 3 compacted -fill soils placed in 2002 are also comprised of onsite -derived and imported soil and bedrock materials and consisted generally of fine to coarse sand, silty sand and clayey sand. The imported materials were generated during post grading operations within nearby Tract 23065. ' 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 observed within the Pauba Formation. SUMMARY OF EARTHWORK ' OBSERVATIONS AND DENSITY TESTING Clearing and Grubbing Heavy vegetation that existed in local areas, as well as some construction debris, were ' removed from the site. Ground Preparation ' 1988 - 1990 - During the interface grading perfonned in 1989 and 1990, unsuitable ' soils, such as alluvium, colluvium and weathered bedrock, were removed and replaced with compacted fill. Removal of unsuitable soils was performed at that time to facilitate future grading by reducing the need to encroach into the completed golf -course fairways during rough grading of the subject tract. Removal of unsuitable soils extended laterally from the golf course into the subject tract at a 1:1 (horizontal: vertical [h:v]) projection from the proposed toe -of -slopes to the ' bottom of the overexcavation in order to provide lateral support for the embankment fills. As a result of the removals, the alluvial soils anticipated to be subject to hydrocollapse or consolidation that existed within the broader valley ' areas were removed. In areas to receive compacted fill, deposits of existing low- density surficial soils (slopewash and alluvium) were removed to competent bedrock. In general, removal of unsuitable surficial materials varied from ' approximately 3 to 10 feet below the original ground surface. Removals were also extended into adjacent street areas which were to receive compacted fill. ' 2002 - Prior to placing structural fill, existing low-density surficial soils were first removed to undisturbed, unweathered bedrock or previously placed compacted -fill materials. Removals varied from approximately 2 to 8 feet. Approximately 5 feet • V I RICHMOND AMERICAN HOMES June 25, 2003 TR 23066-3 Lots 18-26 & 96-98/Temecula Area J.N. 188-01 Page 4 of the rear portion of Lots 23 and 24 were overexcavated about 2 feet. Overexcavations were not performed within these lots due to the shallow and localized area of the removals which were outside of the building -pad areas. Previously compacted -fill materials exposed in removal areas exhibited an in-place relative compaction of 90 percent or more at the locations tested. Prior to placing fill, exposed bottom surfaces in removal areas were observed by our project geologist or senior soil technician. 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 in-place to a relative compaction of 90 percent or more. Lot Overexcavations To reduce the likelihood of distress to residential structures related to the potential adverse effects of differential settlement, the cut portion of cut/fill transition lots were overexcavated to a depth of 3 feet or more below finish grade and replaced with compacted fill. Fill Placement and Testing Fill soils were placed in loose lifts approximately 6 to 8 inches in thickness, watered or air-dried as necessary to achieve near -optimum moisture conditions and then compacted in-place until density tests indicated relative compaction of 90 percent or more based on ASTM D1557. Compaction was achieved by wheel -rolling with an 824 rubber -tired loader and loaded scrapers. The deepest fill placed within the subject lots was approximately 7.5 feet on Lot 98. Field density and moisture content tests were performed in accordance with nuclear - gauge test methods (ASTM D2922 and D3017). Occasional field density tests were 1 W - 11 1 RICHMOND AMERICAN HOMES June 25, 2003 TR 23066-3 Lots 18-26 & 96-98/Temecula Area J.N. 188-01 Page 5 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 the enclosed Geotechnical Map with Density Test Locations (Figure 1). Field density tests were taken at vertical intervals of approximately 1 to 2 feet and the compacted fills were tested at the time of placement to document that the specified moisture content and required relative compaction of 90 percent or more 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 earthmovers (scrapers) and availability of support equipment. When field density tests produced results less than the recommended relative compaction of 90 percent or if the soils were found to be above or below specified optimum 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. Single -point checks were performed to supplement visual classification. Fill Slopes Fill slopes were constructed at a ratio of approximately 2:1 (h:v) and to a height of approximately 4 feet. Fill slopes were overfilled an average of 4 to 5 feet during construction and then trirmned back to the compacted core. The fill slopes were considered grossly and surficially stable to the heights and inclinations at which they were constructed. 1 • a RICHMOND AMERICAN HOMES June 25, 2003 TR 23066-3 Lots 18-26 & 96-98/Temecula Area J.N. 188-01 Page 6 Cut Slopes Cut slopes exposed competent Pauba Formation bedrock and were constructed at a ratio of approximately 2:1 (h:v) and to a height of approximately 8 feet (Lot 21) or less. The cut slopes were considered grossly and surficially stable to the heights and slope ratios at which they were constructed. Construction -Material Storage Portions of the subject lots have been used for construction -material storage and staging. We suggest that the condition of these lots be observed just prior to trenching to verify that conditions are as described. LABORATORY TESTING Maximum Dry Density Maximum dry density and optimun moisture content for changes in soil types observed during grading were determined in our laboratory in accordance with ASTM D1557. Pertinent test values for each phase of grading (1989 and 2002) 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 perfonned in accordance with ASTM D4829. Test results indicated that surficial soils had VERY LOW and MEDIUM expansion potential. [J 1 I ' RICHMOND AMERICAN HOMES June 25, 2003 TR 23066-3 Lots 18-26 & 96-98/Temecula Area J.N. 188-01 ' Page 7 ' Atterberg Limits Atterberg limits were determined for selected soil samples per ASTM D4318. Test results are presented in Appendix A. ' Soluble Sulfate Analvses Soluble sulfate contents were determined for representative samples of soil existing at or near finish grade within the subject lots. These tests were performed in accordance with California Test Method No. 417. Test results are provided in Appendix A. Test results indicated that soluble -sulfate contents were negligible. Therefore, according to 1997 Uniform Building Code (UBC) Table 19-A-4, no special ' cement is specified for concrete to be placed in contact with onsite soils. However, we recommend that Type II cement be used for concrete. For concrete in contact with the ' soil, we recommend that 3 inches or more of concrete be placed over reinforcing steel. Chloride Resistivity and pH Anal ' Water-soluble chloride concentration, resistivity and pH values were determined for selected samples in accordance with California Test Method Nos. 422 (chloride) and 643 (resistivity and pH). The results of these analyses are provided in Appendix A. Test results indicated that soils were moderately corrosive to ferrous metal. Ferrous metal pipe, if used, should be corrosion -protected or an alternative piping that is not subject to corrosion, such as plastic pipe, should be used. We recommend that a corrosion engineer be consulted to provide further recommendations. I I I I I I I I RICHMOND AMERICAN HOMES June 25, 2003 TR 23066-3 Lots 18-26 & 96-98/Temecula Area J.N. 188-01 Page 8 CONCLUSIONS AND RECOMMENDATIONS Foundation -Design Recommendations Foundation Types Based on as -graded soil and geologic conditions, the use of conventional slab -on - ground foundations is considered feasible for the subject lots. As an alternative, based on moderately expansive soils which exist within the upper 5 feet of the pad, a post - tension slab foundation system may be considered for residential structures on Lots 18 through 21. Recommended design parameters are provided herein. 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. 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. 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. ra I RICHMOND AMERICAN HOMES June 25, 2003 TR 23066-3 Lots 18-26 & 96-98/Temecula Area J.N. 188-01 Page 9 Lateral Resistance A passive earth pressure of 250 psf per foot of depth to a value of 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 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 0.35 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. In the case where footing sides are fonned, backfill against the footings should be compacted to 90 percent or more of 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 fomes, reinforcement or concrete. The excavations should be trimmed neat, level and square. Loose, sloughed or moisture -softened soil and construction debris should be removed prior to placing concrete. Excavated soils derived from footing excavations should not be placed within slab -on -ground areas. Expansive Soil Considerations Laboratory testing of soils within the site indicate soils exhibit VERY LOW and MEDIUM expansion potentials as classified in accordance with 1997 UBC Table 18 -I -B. W 01 I H RICHMOND AMERICAN HOMES June 25, 2003 TR 23066-3 Lots 18-26 & 96-98/Temecula Area J.N. 188-01 Page 10 Very Low Expansion Potential (Expansion Index of 20 or less) The results of our laboratory tests indicate that onsite soils within Lots 22 through 26 and 96 through 98 exhibit VERY LOW expansion potential as classified in accordance with 1997 UBC Table 18-1-13. 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 be reinforced with two No. 4 bars, one top and one bottom. - Isolated pad footings should be 24 inches or more square and founded at a depth of 12 inches or more below the lowest adjacent final grade or top -of -slab. • Floor Slabs Living -area concrete -floor slabs should be 4 inches or more thick and reinforced with either 6x6 -W 1.4xW 1.4 welded -wire mesh or with No. 3 bars spaced 24 inches on -centers, both ways. Slab reinforcement should be supported on concrete chairs or bricks so that the desired placement is near 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 • /I I ' RICHMOND AMERICAN HOMES .Tune 25, 2003 TR 23066-3 Lots 18-26 & 96-98/Temecula Area J.N. 188-01 Page 11 ' 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. - Prior to placing concrete, subgrade soils should be thoroughly moistened to promote uniform curing of the concrete and reduce the development of shrinkage cracks. Medium Expansion Potential (_Expansion Index of 51 to 90) The following recommendations pertain to as -graded Lots 18 through 21 which exhibit a MEDIUM expansion potential as classified in accordance with 1997 UBC Table 18-1-B. We are assuming an effective plasticity index of 15 as defined in 1997 UBC Section 1815.4.2. The design and construction recommendations that follow may be considered for reducing the effects of moderately expansive soils. These recommendations have been based on the previous experience of Petra on projects with similar soil conditions and design criteria presented in 1997 UBC Section 1815. Although construction performed in accordance with these recommendations has been found to reduce post - construction movement and/or cracking, they generally do not mitigate potential detrimental effects of expansive soil movement. The owner, architect, design civil engineer, structural engineer and contractors should be made aware of the expansive - soil conditions which exist at the site. Furthermore, it is recommended that additional slab thicknesses, footing sizes and/or reinforcement more stringent than recommended below be provided as required or specified by the project architect or structural engineer. • Footings - Exterior continuous footings for both one- and two-story construction should be founded at a depth of 18 inches or greater below the lowest adjacent final grade. I I RICHMOND AMERICAN HOMES June 25, 2003 TR 23066-3 Lots 18-26 & 96-98/Temecula Area J.N. 188-01 Page 12 Interior continuous footings may be founded at a depth of 12 inches or greater below top -of -slab for both one- and two-story construction. Continuous footings should have a width of 12 and 15 inches or greater, for one- and two- story buildings, respectively, and should be reinforced with four No. 4 bars, two top and two bottom. ' Exterior pad footings intended for the support of roof overhangs, such as second -story decks, patio covers and similar construction, should be 24 inches square or greater and founded at a depth of 18 inches or greater below the lowest adjacent final grade. The pad footings should be reinforced in accordance with the structural engineer's recommendations. • Floor Slabs Unless a more stringent design is recommended by the architect or the structural ' engineer, we recommend a slab thickness of 4 inches or greater for both living - area and garage -floor slabs and reinforcing consisting of No. 3 bars spaced 18 inches or less on -centers, both ways. Slab reinforcement should be supported ' on concrete chairs or bricks so that the desired location near mid -height is achieved. t - Living -area concrete -floor slabs should be underlain with a moisture -vapor retardant consisting of 6 -mil polyethylene membrane or equivalent. Laps within the membrane should be sealed and 2 inches or more of clean sand be placed over the membrane to promote uniform curing of the concrete. ' - Garage -floor slabs should be placed separately fi-om adjacent wall footings with a positive separation maintained with 3/8 -inch, felt expansion -joint materials and quartered with weakened-planejoints. A 12 -inch wide grade beam founded 1 at the same depth as adjacent footings should be provided across garage entrances. The grade beam should be reinforced with four No. 4 bars, two top and two bottom. ' Prior to placing concrete, the subgrade soils below living -area and garage -floor slabs should be pre -watered to achieve a moisture content that is 5 percent or greater than optimum -moisture content. This moisture content should penetrate to a depth of 18 inches or more into the subgrade soils. • 13 I RICHMOND AMERICAN HOMES TR 23066-3 Lots 18-26 & 96-98/Temecula Area POST -TENSIONED SLABS June 25, 2003 J.N. 188-01 Page 13 In lieu of the preceding recommendations for conventional footings and floor slabs, post -tensioned slabs may be used. The actual design of post -tensioned slabs is referred to the project structural engineer who is qualified in post -tensioned slab design, using sound engineering practices. The post -tensioned slab -on -ground should be designed in general conformance with the design specification presented in 1997 UBC Section 1816. Alternate designs are allowed per 1997 UBC Section 1806.2 that address the effects of expansive soils when present. However, to assist the structural engineer in his design, the following parameters are recommended. -,: - _ Eipnnsion I" ndex r VcggLoe -�,(0-{050) t b ' Medwm,. „aiSLlo"90)_i Assumed percent clay 30 70 Clay type Monhnorillonile Approximate depth of constant suction (feet) 7.0 7.0 Approximate soil suction (pF) 3.6 3.6 Approximate velocity or moisture flow (inches/month) 0.7 0.7 Thomwaite Index -20 -20 Average edge Moisture variation depth, em (feet) Centel lift 4.6 5.3 Edge lift 2.2 2.5 Anticipated swell, g„ (inches) Centellilt 1.4 2.3 Ed -e lift 0.4 1.1 • Perimeter footings for either one- or two-story dwellings maybe founded at a depth of 12 inches or more below the nearest adjacent final -ground surface. Interior footings may be founded at a depth of 12 inches or more below the top of the finish -floor slab. • Dwelling -area floor slabs constructed on -ground should be underlain with a moisture -vapor barrier consisting of a polyethylene membrane. One inch or more of clean sand should be placed over the membrane to promote unifoml curing of the concrete. I it /( ' Type B fault, which is the Elsinore -Temecula located approximately 1.3 kilometers to 1 • 15 RICHMOND AMERICAN HOMES June 25, 2003 TR 23066-3 Lots 18-26 & 96-98/Temecula Area J.N. 188-01 ' Page 14 • Presaturation of subgrade soils below slabs -on -ground will not be required. ' However, subgrade soils should be moistened prior to placing concrete. • The design modulus of subgrade reaction (k) should be 300 tons per cubic foot. 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. 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 1 • 15 I 1 RICHMOND AMERICAN HOMES TR 23066-3 Lots 18-26 & 96-98/Temecula Area June 25, 2003 J.N. 188-01 Page 15 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. 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 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 1 %/-02 S D lv /6 1997 UBC TABLE FACTOR Figure 16-2 Seismic Zone 4 16-I 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 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 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 1 %/-02 S D lv /6 I ■ RICHMOND AMERICAN HOMES June 25, 2003 TR 23066-3 Lots 18-26 & 96-98/Temecula Area J.N. 188-01 ' Page 16 height) is maintained between the outside bottom edges of the footings and the slope 1 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) be used for design of cantilevered walls retaining a drained, level 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. 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 1 �7 11 C 1 RICHMOND AMERICAN HOMES June 25, 2003 TR 23066-3 Lots 18-26 & 96-98/Temecula Area J.N. 188-01 Page 17 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 prevent 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 permeable drain material is used, the backdrain should be 1 or more feet thick. Caltrans Class II 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 (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 outside portions of retaining walls supporting backfill should be coated with an approved waterproofing compound to inhibit infiltration of moisture through the walls. Temporary Excavations To facilitate retaining -wall construction, temporary slopes may be cut back at a gradient of 1:1 (h:v) or gentler for the duration of construction. However, temporary slopes should be observed by the project geotechnical consultant for evidence of /� I I I I I RICHMOND AMERICAN HOMES June 25, 2003 TR 23066-3 Lots 18-26 & 96-98/Temecula Area J.N. 188-01 Page 18 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. 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 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 to Low expansion soils and four No. 4 bars, two top and two bottom for Medium 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 constriction. 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 inches below the lowest adjacent final grade. These footings should also be reinforced ot 19 I I I RICHMOND AMERICAN HOMES June 25, 2003 TR 23066-3 Lots 18-26 & 96-98/Temecula Area J.N. 188-01 Page 19 with two No. 4 bars, one top and one bottom for Very Low to Low expansion soils and four No. 4 bars, two top and two bottom for Medium expansion soils. 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 coiner. 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. CONCRETE FLATWORK Thickness and Joint Spacing To reduce the potential of unsightly cracking, concrete sidewalks and patio -type slabs should be 4 inches or more thick. Concrete -driveway slabs should be 4 inches or more thick. Subgrade Preparation As a further measure to reduce cracking of concrete flatwork, the subgrade soils below concrete-flatwork areas should first be compacted to a relative density of 90 percent or more and then wetted 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. It ,,? U I I 1 [1 I 1 RICHMOND AMERICAN HOMES June 25, 2003 TR 23066-3 Lots 18-26 & 96-98/Temecula Area J.N. 188-01 Page 20 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. 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. 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. 1/ I I RICHMOND AMERICAN HOMES June 25, 2003 TR 23066-3 Lots 18-26 & 96-98/Temecula Area J.N. 188-01 Page 21 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 landscaped and maintained thereafter in accordance with the following recommendations. • Compacted -earth berms should be constructed along the tops of the engineered fill slopes to reduce the likelihood of water from flowing directly onto the slope surfaces. • The 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. it 01 eZ I 1 RICHMOND AMERICAN HOMES June 25, 2003 TR 23066-3 Lots 18-26 & 96-98/Temecula Area J.N. 188-01 Page 22 • 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 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 constriction. • Building Construction - Observe footing trenches when first excavated to document specified depth and competent soil -bearing conditions. - Observe pre-soaking 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. 4 23 RICHMOND AMERICAN HOMES June 25, 2003 TR 23066-3 Lots 18-26 & 96-98/Temecula Area J.N. 188-01 Page 23 • Masonry Block -Wall Construction - Observe footing trenches when first excavated to document depth and presence of competent soil -bearing conditions. • Exterior Concrete-Flatwork Construction - Observe and test subgrade soils below concrete- fl atwork areas to document compaction and moisture content. • 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. .�y I I 1 1 [1 RICHMOND AMERICAN HOMES June 25, 2003 TR 23066-3 Lots 18-26 & 96-98/Temecula Area J.N. 188-01 Page 24 This opportunity to be of service is sincerely appreciated. If you have questions, please contact this office. Respectfully submitted, Cliffiofd A. Craft, GE V Principal Engineer �oPp ALE,l, Fyc\ C9 Attachments: Table I - Lot -By -Lot Summary of As -Graded Soil Co 4 —91o. GE000943 Table II - Field Density Test Results * 6" Ex°/2�3I/Q6 F p� References sf °rECHN\° P Figure 1 - Geotechnical Map with Density Test Location 9TFOF CAI -0 Appendix A - Laboratory Test Criteria/Laboratory Test Data Appendix B - Seismic Analysis Distribution: (1) Addressee (3) Richmond American Homes Attention: Ms. Dee Gallegos (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 It 1�5 EXPLANATION (LOCATIONS ARE APPROXIMATE) afc ARTIFICIAL FILL, COM ri 1-Z os ,7 41- -CIO AV - far h.83.., TC I .1 77- '0 0 OFti I I - TC 05 PS-.. J 49- 5 7 \`f� b, GEOTECHNICAL MAP WITH DENSITY TEST LOCATIONS TRACT 23066-3 LOTS 18-26 AND 96-98 0% INNZ__� *mk PETRA GEOTECHNICAL, INC. 0 Scale 40 Feet JN 188-01 JUNE 2003 FIGURE 1 QUATERNARY PAUBA FORMATION GEOLOGIC CONTACT 5 BEDDING ATTITUDE JOINT ATTITUDE 1569 DENSITY TEST LOCATION ,7 41- -CIO AV - far h.83.., TC I .1 77- '0 0 OFti I I - TC 05 PS-.. J 49- 5 7 \`f� b, GEOTECHNICAL MAP WITH DENSITY TEST LOCATIONS TRACT 23066-3 LOTS 18-26 AND 96-98 0% INNZ__� *mk PETRA GEOTECHNICAL, INC. 0 Scale 40 Feet JN 188-01 JUNE 2003 FIGURE 1 TABLE I Tract 23066-3 Lots 18-26 & 96-98 LOT -BY -LOT SUMMARY OF SOIL CONDITIONS Lot Number Fill Depth (ft) Differential Fill Thickness (ft) Estimated Differential Settlement Soil Expansion Index/ Potential Post- Tensioned Slab Sulfate Exposure Soil Condition Codes* Remarks IS 0 0 1:960 45/Medium optional negligible EP 19 0 0 1:960 45/Medium optional negligible EP 20 0 0 1:960 45/Medium optional negligible EP 21 0 0 1:960 45/Medium optional negligible EP 22 0 0 1:960 0 /V. Low NO negligible Z 23 2 2 1:960 0 /V. Low NO negligible Z 24 2 2 1:960 0 /V. Low NO negligible Z 25 0 0 1:960 0 /V. Low NO negligible Z 26 0 0 1:960 0 /V. Low NO negligible Z 96 6.5 3.5 1:960 10/V. Low NO negligible Z 97 7.0 4.0 1:960 10 /V. Low NO negligible Z 98 7.5 4.5 1:960 8 /V. Low NO negligible Z * per County of Riverside, Building and Safety Department Plan Check Memorandum dated April 5, 2001 Code Defnitioos (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 -III -GG (consider Prefab Roof Trusses) [noted if>1:4801 P If post -tensioned slab system is to be used Z If none of the above is applicable TABLE 11 Field Density Test Results 06/12/02 1508 Lot 98 FG 9.8 118.6 91* 9 06/12/02 1510 Lot 97 FG 9.8 118.2 90 9 06/12/02 1511 Lot 96 FG 8.9 119.2 92 4 06/14/02 1568 Lot 96 1206.0 11.9 118.3 91 10 06/14/02 1569 Lot 97 1203.0 12.9 119.8 90 11 07/23/02 1889 Lot 97 FG 8.1 118.3 91* 9 07/23/02 1890 Lot 98 FG 9.2 118.7 90* 9 07/23/02 1891 Lot 96 FG 7.5 119.2 91* 9 PETRA GEOTECHNICAL, INC. TR 23066-3/Lots 96 - 98 JUNE 2003 J.N. 188-01 2002 TABLE -II 1 ,�7 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 1997. 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, 1987. ' , 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, 1988. ' Kennedy, M.P., 1977, Recency and Character of Faulting Along the Elsinore Fault Zone in Southem 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 II, J.N. 298-87, dated May 8, 1989. ' , 2001a, 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, 2001. 2001b, Supplemental Geotechnical Investigation, Tract 23066-3, Lot 129, Redhawk Development, Temecula Area, Riverside County, California, J.N. 188-01, dated April, 18, 2001. ' , 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. , 2001d, 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. t, 2001 e, Geoteckmical 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, 2001. ' , 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, 2002. ' , 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, 2002. ' 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, 2002. PETRA GEOTECHNICAL, INC. JUNE 2003 J. N. 188-01 J9, I 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, 2002. , 2002e, Preliminary Geotechnical Recommendations Regarding Expansive Soils, Phase 1, Tract 23066-2, Lots 10 through 39, Temecula Area, Riverside County, California, J.N. 188-01, dated April 3, 2002. , 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, 2002. , 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, 2002. 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, 2002. , 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, 2002. , 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, 2002. , 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. 2002. , 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, 2002. , 2003, Geotechnical Report of Rough Grading, Lots 27 through 38, Tract 23066-3, Temecula Area, Riverside County, California, J.N. 188-01, dated April 15, 2003. PETRA GEOTECHNICAL, INC. JUNE 2003 J. N. 188-01 aq APPENDIX A LABORATORY TEST CRITERIA LABORATORY TEST DATA 7;e,�230�65-/ -c2, -1 1 PETRA 30 APPENDIX A LABORATORY TEST CRITERIA Laboratory Maximum Dry Density Maximum dry density and optimum moisture content were determined for selected samples of soil and bedrock materials in accordance with ASTM D1557. Pertinent test values are given on Plate A-1. Expansion Index Expansion index tests were performed on selected samples of soil in accordance with ASTM D4829. Expansion potential classifications were determined 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-2. Corrosivity Tests 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-2. Atterberg Limits Atterberg limit tests (Liquid Limit and Plastic Index) were performed on selected samples to verify visual classifications. These tests were performed in accordance with ASTM D4318. Test results are presented on Plate A-2. PETRA GEOTECHNICAL, INC. JUNE 2003 J. N. 188-01 RM I 1 1 LABORATORY MAXIMUM DRY DENSITY' 1 iLt 3 4 ii kip; Six^. .h. 34 1 1 hE'vl i {1 !`l .'S3�'(.`��� ba'F t �i.�t Y �✓'N: $y4 ett' d" 1 r a t�-'1 1 t ''a`rvlfdk4� Optunumt it Y4 Maximum. . �Sainple �` . SocilrTyper} „�,t7� �;,� aMmsture g DrytDensrt} 23 22 through 26 0 Very Low 96 96 through 97 10 Very Low 4 Light Brown Silty, Clayey Fine to Medium SAND 10.0 128.5 9 Light Brown Silty SAND with Trace Clay 10.0 130.5 10 Brown Clayey SILT 11.5 124.5 11 Brown Clayey Cobbly SAND 8.5 133.5 EXPANSION INDEX TEST DATA 'L'tl 4(9 Lot No ....i.Ri�'af' ,� 4 d �K R Representative Lotsr� = 7 k Cil `'�{a Z,f Expanston a 4 i Expanston;� x"Poten"tirC, 19 18 through 21 45 Medium 23 22 through 26 0 Very Low 96 96 through 97 10 Very Low 98 98 8 Very Low (1) PER ASTM D1557 (2) PER ASTM D4829 (3) PER 1997 UBC TABLE 18-1-B ' PETRA GEOTECHNICAL, INC. JUNE 2003 ' J. N. 188-01 Plate A-1 1 3;)- SOIL CHEMISTRY tvYil?IU. r8U �.,Zl fNNumber Ki ` `s`�61 Ai 3a Srrlfate 4 rC�hlonde I' pH ct k Resrstrvit3 ,� i ostvrty- Potentrala� 98 N/D 138 7.9 2,100 concrete: negligible ,F 4 Silty, Clayey SAND steel: corrosive 19 0.006 140 7.3 3,300 concrete: negligible 8 steel: moderate ATTERBERG LIMITSe sdnQ q"`��'f s -s =� $; 4 S'k�{p hak ¢ 1'i mit - "' C4ynlS TlEa kLlQllldy i._ (�tCNM,� P1aStIC ¢y,3NC`R"ii 41 Plastkitj'(e t $u w �v' ..a ..y 4 5" SampleiNo.,� r�4°- ,�, ^. '-� .ew r ��„°'�,�0. {.�s i .�t it .yyk ..yM� g210i t.'� {n1E" Y '$) 1 9ji, VcSoiltTy e, { � ^P�'s.bw"' A Lrmit 4 7i .ted 6� Lrmrt l _: ,p r �� Index;„ .* ,'�, � '4 . ,F 4 Silty, Clayey SAND 32 15 17 11 Clayey medium to coarse SAND with cobbles 26 18 8 (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 (8) PER ASTM D4318 PETRA GEOTECHNICAL, INC. JUNE 2003 J.N. 188-01 Plate A-2 13 I 1 APPENDIX B SEISMIC ANALYSIS 1 PETRA 'if, U B C S E I S version 1.03 COMPUTATION OF 1997 UNIFORM BUILDING CODE SEISMIC DESIGN PARAMETERS JOB NUMBER: 188-01 DATE: 04-13-20 02 JOB NAME: Richmond Redhaw FAULT -DATA -FILE NAME: CDMGUBCR.DAT SITE COORDINATES: SITE LATITUDE: 33.4677 SITE LONGITUDE: 117.0860 UBC SEISMIC ZONE: 0.4 UBC SOIL PROFILE TYPE: SO NEAREST TYPE A FAULT: NAME: ELSINORE-JULIAN DISTANCE: 12.1 km NEAREST TYPE B FAULT: NAME: ELSINORE-TEMECULA DISTANCE: 1.3 km NEAREST TYPE C FAULT: NAME: DISTANCE: 99999.0 km SELECTED UBC SEISMIC COEFFICIENTS: Na: 1.3 Nv: 1.6 Ca: O.S7 Cv: 1.02 Ts: 0.716 To: 0.143 Page 1 3s VU 1 CAUTION: The digitized data points used to model faults are limited in number and have been digitized from small scale maps (e.g., 1:750,000 scale). Consequently, the estimated fault -site -distances may be in error b y several kilometers. Therefore, it is important that the distances be carefully checked for accuracy and adjusted as needed, before they are used in design. SUMMARY OF FAULT PARAMETERS --------------------------- Page 1 ------------------------------------------------------------------- ------------ I FAULT ABBREVIATED TYPE FAULT NAME I(SS,DS,BT) ------------------------------ ELSINORE-TEMECULA I SS ELSINORE-JULIAN I SS ELSINORE-GLEN IVY I SS SAN JACINTO-ANZA I SS SAN JACINTO-SAN JACINTO VALLEY I SS NEWPORT-INGLEWOOD (Offshore) I SS ROSE CANYON I SS SAN JACINTO-COYOTE CREEK I SS EARTHQUAKE VALLEY I APPROX.ISOURCE I MAX. I SLIP IDISTANCEI TYPE I MAG. I RATE I (km) I(A,B,C)I (Mw) I (mm/yr) I 2.6 I B I 6.8 I 5.00 I 12.1 I A I 7.1 I 5.00 31.2 I B I 6.8 I 5.00 I 33.3 I A I 7.2 I 12.00 I 34.1 I B I 6.9 I 12.00 I 46.5 I B ( 6.9 I 1.50 49.0 I B I 6.9 I 1.50 I 53.6 I B I 6.8 I 4.00 I 56.6 I B I 6.5 I 2.00 Page 2 36 I SS CHINO -CENTRAL AVE. (Elsinore) I 60.0 I B I 6.7 I 1.00 I DS SAN JACINTO-SAN BERNARDINO 1 62.7 ( B I 6.7 I 12.00 I SS SAN ANDREAS - Southern I 63.0 1 A I 7.4 I 24.00 1 SS ELSINORE-WHITTIER I 66.8 I B I 6.8 I 2.50 1 SS PINTO MOUNTAIN I 73.8 1 B I 7.0 I 2.50 1 SS CORONADO BANK 1 74.1 1 B I 7.4 ( 3.00 1 SS NEWPORT-INGLEWOOD (L.A.Basin) I 79.1 I B 6.9 1 1.00 I SS PALO!:) VERDES I 81.5 I B 1 7.1 I 3.00 1 SS BURNT MTN. I 84.6 B I 6.5 I 0.60 1 SS CUCAMONGA 86.0 1 A 1 7.0 5.00 1 DS ELSINORE-COYOTE MOUNTAIN 1 87.4 I B I 6.8 I 4.00 1 SS NORTH FRONTAL FAULT ZONE (West) I 87.8 B I 7.0 I 1.00 I DS SAN JACINTO - BORREGO I 87.9 1 B 1 6.6 1 4.00 1 SS EUREKA PEAK 1 89.1 I B 1 6.5 1 0.60 1 SS NORTH FRONTAL FAULT ZONE (East) 1 90.4 B I 6.7 I 0.50 I DS SAN JOSE 1 91.0 1 B 1 6.5 I 0.50 I DS CLEGHORN 91.1 1 B I 6.5 3.00 1 SS SIERRA MADRE (Central) 1 94.8 1 B I 7.0 I 3.00 1 DS LANDERS I 99.2 I B I 7.3 1 0.60 1 SS HELENDALE - S. LOCKHARDT 1 102.4 I B 1 7.1 I 0.60 1 SS SAN ANDREAS - 1857 Rupture I 102.4 I A I 7.8 1 34.00 1 SS LENWOOD-LOCKHART-OLD WOMAN SPRGS I 107.0 1 B 1 7.3 I 0.60 1 SS CLAMSHELL-SAWPIT I 111.1 1 B I 6.5 I 0.50 I DS JOHNSON VALLEY (Northern) 1 111.6 I B 1 6.7 I 0.60 1 SS EMERSON So. - COPPER MTN. I 112.9 1 B 1 6.9 I 0.60 1 SS RAYMOND I 115.4 i B I 6.5 I 0.50 Page 3 3? VV1 I DS SUPERSTITION MTN. (San Jacinto) SS VERDUGO I DS ELMORE RANCH I SS PISGAH-BULLION MTN.-MESQUITE LK I SS CALICO - HIDALGO I SS SUPERSTITION HILLS (San Jacinto) I SS HOLLYWOOD I DS BRAWLEY SEISMIC ZONE SS ELSINORE-LAGUNA SALADA SS SANTA MONICA DS SIERRA MADRE (San Fernando) I DS 9 14 I 120:2 I B I 6.6 I 5.00 I 123.5 I B I 6.7 I 0.50 I 124.2 I B I 6.6 I 1.00 I 124.3 I B I 7.1 1 0.60 I 125.0 I B I 7.1 I 0.60 I 126.3 I B I 6.6 I 4.00 I 128.5 I B I 6.5 I 1.00 128.6 I B I 6.5 I 25.00 I 138.9 I B I 7.0 I 3.50 1 140.4 I B I 6.6 I 1.00 I 143.8 I B 6.7 I 2.00 --------------------------- SUMMARY OF FAULT PARAMETERS --------------------------- Page 4 0 I APPROX.ISOURCE I MAX. I SLIP FAULT ABBREVIATED DISTANCEI TYPE I MAG. I RATE TYPE FAULT NAME I (km) I(A,B,C)I (Mw) I (mm/yr) I(SS,DS,BT) SAN GABRIEL 1 145.6 I B I 7.0 I 1.00 I SS MALIBU COAST I 148.1 I B I 6.7 I 0.30 1 DS IMPERIAL I 153.5 I A I 7.0 I 20.00 1 SS GRAVEL HILLS - HARPER LAKE I 157.0 I B 6.9 I 0.60 1 SS ANACAPA-DUME 1 159.9 B I 7.3 1 3.00 1 DS Page 4 0 U U1' ' SANTA SUSANA. 1 161.7 I B 1 6.6 I 5.00 I DS HOLSER I 170.7 1 B 1 6.5 1 0.40 ' 1 Ds BLACKWATER 1 173.2 1 B 1 6.9 1 0.60 1 SS OAK RIDGE (Onshore) 1 181.7 1 B 1 6.9 I 4.00 ' 1 DS SIMI-SANTA ROSA 1 183.3 1 B 1 6.7 1 1.00 I Ds ' SAN CAYETANO 1 189.1 I B I 6.8 1 6.00 1 DS SANTA YNEZ (East) I 208.3 I B 1 7.0 I 2.00 ' 1 SS GARLOCK (West) 1 213.3 1 A 1 7.1 1 6.00 1 SS VENTURA - PITAS POINT 1 214.2 I B 1 6.8 1 1.00 ' I DS GARLOCK (East) I 219.9 I A I 7.3 7.00 I SS ' M.RIDGE-ARROYO PARIDA-SANTA ANA I 222.8 1 B 1 6.7 1 0.40 1 DS PLEITO THRUST I 225.2 I B I 6.8 1 2.00 1 DS RED MOUNTAIN 1 228.5 1 B 1 6.8 1 2.00 I DS SANTA CRUZ ISLAND I 232.7 B 1 6.8 I 1.00 ' I DS BIG PINE 1 233.2 i B 1 6.7 1 0.80 I ss ' OWL LAKE 1 238.6 I B 1 6.5 1 2.00 1 SS PANAMINT VALLEY I 238.9 I B I 7.2 1 2.50 ' 1 SS WHITE WOLF 1 240.0 1 B 1 7.2 1 2.00 1 DS TANK CANYON 1 242.2 1 B I 6.5 1 1.00 ' 1 DS So. SIERRA NEVADA 1 242.6 I B 1 7.1 1 0.10 I DS ' LITTLE LAKE 1 243.9 1 B I 6.7 1 0.70 1 SS DEATH VALLEY (South) 1 245.3 I B 1 6.9 I 4.00 ' 1 SS SANTA YNEZ (West) 1 262.0 B 1 6.9 1 2.00 1 SS SANTA ROSA ISLAND 1 268.8 1 B 1 6.9 I 1.00 ' I Ds DEATH VALLEY (Graben) I 288.9.1 B I 6.9 1 4.00 I DS ' LOS ALAMOS -W. BASELINE 1 305.1 1 B 1 6.8 1 0.70 I DS ' Page 5 39 Uui OWENS VALLEY I SS LIONS HEAD I DS SAN JUAN I SS SAN LUIS RANGE (S. Margin) I. DS HUNTER MTN. - SALINE VALLEY I SS CASMALIA (Orcutt Frontal Fault) I DS DEATH VALLEY (Northern) I SS INDEPENDENCE I DS LOS OSOS I DS HOSGRI I SS RINCONADA I SS BIRCH CREEK I DS WHITE MOUNTAINS I SS DEEP SPRINGS I DS SAN ANDREAS (Creeping) I SS I 314.0 I B I 7.6 I 1.50 I 322.5 I B I 6.6 I 0.02 I 325.6 I B I 7.0 I 1.00 I 330.2 I B I 7.0 I 0.20 I 336.2 I B I 7.0 I 2.50 I 339.8 I B I 6.5 I 0.25 I 342.9 I A I 7.2 I 5.00 I 350.0 I B I 6.9 I 0.20 I 359.5 I B I 6.8 I 0.50 I 368.7 I B I 7.3 I 2.50 I 377.7 I B I 7.3 I 1.00 I 406.9 I B I 6.5 I 0.70 410.4 I B I 7.1 I 1.00 428.0 I B I 6.6 I 0.80 I 428.1 ( B 5.0 I 34.00 --------------------------- SUMMARY OF FAULT PARAMETERS --------------------------- Page 3 ------------------------------------------------------------------- ------------ I FAULT ABBREVIATED I TYPE FAULT NAME I(SS,DS,BT) ------------------------------ DEATH VALLEY (N. of Cucamongo) I SS ROUND VALLEY (E. of S.N.Mtns.) I APPROX.ISOURCE I MAX. I SLIP IDISTANCEI TYPE I MAG. I RATE I (km) I(A,B,C)I (MW) I (mm/Yr) I 431.0 I A I 7.0 5.00 I 443.2 I B I 6.8 I 1.00 Page 6 yb ' DS FI ISH SLOUGH I 449.6 I B I 6.6 I 0.20 ' HILTONDCREEK I 469.5 I B I 6.7 I 2.50 I DS HARTLEY SPRINGS I 494.6 I B I 6.6 I 0.50 I DS ' ORTIGALITA I 509.4 I B I 6.9 I 1.00 I SS CALAVERAS (So.of Calaveras Res) I 517.1 I B I 6.2 I 15.00 ' I SS MONTEREY BAY - TULARCITOS I 523.1 I B I 7.1 I O.SO I DS ' PALO COLORADO - SUR I 526.3 I B I 7.0 I 3.00 I SS QUIEN SABE I 529.7 I B I 6.5 I 1.00 I SS ' MONO LAKE 530.8 I B I 6.6 I 2.50 DS ZAYANTE-VERGELES 549.2 I B I 6.8 I 0.10 I SS t SARGENT 554.0 I B I 6.8 I 3.00 1 SS ' SAN ANDREAS (1906) 554.4 I A I 7.9 I 24.00 I SS ROBINSON CREEK I 562.3 I B I 6.5 1 0.50 I DS ' SAN GREGORIO 598.2 I A I 7.3 5.00 I SS GREENVILLE I 601.0 I B I 6.9 2.00 ' 1 SS ANTELOPE VALLEY I 603.0 I B I 6.7 1 0.80 ' HAYWARDS(SE Extension) 603.1 I B 6.5 I 3.00 I SS MONTE VISTA - SHANNON 604.1 I B 1 6.5 I 0.40 I DS t HAYWARD (Total Length) I 622.4 I A I 7.1 I 9.00 I SS CALAVERAS (No.of Calaveras Res) I 622.4 I B I 6.8 I 6.00 ' SS GENOA 629.2 I B I 6.9 I 1.00 I DS ' CONCORD - GREEN VALLEY I 668.8 B I 6.9 6.00 RODGERSSCREEK I 708.1 I A I 7.0 I 9.00 1 SS ' WEST NAPA I 708.3 I B I 6.5 I 1.00 I SS POINT REYES I 729.3 I B I 6.8 I 0.30 ' HUNTINGSCREEK BERRYESSA I 729.5 I B I 6.9 I 6.00 Page 7 Y/ U U'1' --------------------------- SUMMARY OF FAULT PARAMETERS --------------------------- Page 4 ------------------------------------------------------------------- ------------ I APPROX.ISOURCE I MAX. I SLIP FAULT ABBREVIATED IDISTANCEI TYPE I MAG. I RATE TYPE Page 8 0- MAACAMAS(South) I 770.1 I B I 6.9 I 9.00 1 SS COLLAYOMI 1 786.2 I B 1 6.5 1 0.60 1 SS BARTLETT SPRINGS 1 788.6 I A 1 7.1 I 6.00 1 SS MAACAMA (Central) I 811.7 I A I 7.1 1 9.00 1 SS MAACAMA (North) I 870.5 I A I 7.1 I 9.00 1 SS ROUND VALLEY (N. S.F.Bay) I 875.3 1 B I 6.8 I 6.00 1 SS BATTLE CREEK 1 892.8 I B I 6.5 I 0.50 1 DS LAKE MOUNTAIN I 933.6 1 B I 6.7 6.00 1 SS GARBERVILLE-BRICELAND ( 951.5 I B 6.9 I 9.00 1 SS MENDOCINO FAULT ZONE 11008.7 1 A 1 7.4 I 35.00 1 DS LITTLE SALMON (Onshore) 11013.7 I A I 7.0 5.00 1 DS MAD RIVER 1 1015.4 I B 1 7.1 1 0.70 1 DS CASCADIA SUBDUCTION ZONE 1023.1 I A 1 8.3 1 35.00 1 DS MCKINLEYVILLE 1 1026.1 1 B I 7.0 1 0.60 1 DS TRINIDAD 11027.4 1 B 1 7.3 I 2.50 I DS FICKLE HILL 1028.2 I B 1 6.9 I 0.60 1 DS TABLE BLUFF 1 1034.4 I B I 7.0 I 0.60 I DS LITTLE SALMON (Offshore) 1047.6 I B 1 7.1 1 1.00 I DS --------------------------- SUMMARY OF FAULT PARAMETERS --------------------------- Page 4 ------------------------------------------------------------------- ------------ I APPROX.ISOURCE I MAX. I SLIP FAULT ABBREVIATED IDISTANCEI TYPE I MAG. I RATE TYPE Page 8 0- vul I FAULT NAME I (km) l(A,B,C)l (Mw) I (mm/yr) I(SS,DS,BT) BIG LAGOON BALD MTN.FLT.ZONE 11063.9 I B I 7.3 I 0.50 DS I I I I I I I I I I I Page 9 413 DESIGN RESPONSE SPECTRUM 2.50 2.25 2.00 CD M, IC, 0.25 0.00 Seismic Zone: 0.4 Soil Profile: SD 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Period Seconds 4.0 4.5 5.0 1.75 0 1.50 1.25 U Q 1.00 4-1 0.75 U a 0.50 M, IC, 0.25 0.00 Seismic Zone: 0.4 Soil Profile: SD 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Period Seconds 4.0 4.5 5.0