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HomeMy WebLinkAboutGeotechRoughGrading(Jun.28,1999) .. I I I I I I I I I I I I I I I I I I o PE'IRA COSTA MESA. SAN DIEGO. TEMECULA . LOS ANGELES June 28, 1999 J.N.444-98 RICHMOND AMERICAN HOMES 104 West Grand Avenue, Suite A Escondido, California 92055 Attention: Mr. John Mecklenburg Subject: Geotechnical Report of Rough Grading, Phase I, Lots 17 through 22 and Lots 57 through 63 of Tract 23143-2; Lots 22 through 27 and Lots 99 through 105 of Tract 23143-3; and Lots 1 through 17 of Tract 23143-4, Crowne Hill, City of Temecula, Riverside County, California This report presents a summary of the observation and testing services provided by " Petra Geoteclmical, Inc. (Petra) during rough-grading operations to develop Phase I lots, Lots 17 through 22 and Lots 57 through 63 of Tract 23143-2; Lots 22 through 27 and Lots 99 through 105 of Tract 23143-3; and Lots I through 17 of Tract 23143-4 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. Lots 12 through 14 of Tract 23143-4 are currently undergoing deep-fill settlement monitoring. The purpose of grading was to develop 43 level lots (13 in Tract 23143-2, 13 in Tract 23143-3 and 17 in Tract 23143-4) for construction of single-family residences, as well as adjacent slopes and streets. Grading on these selected lots began in December 1998, and was completed in April 1999. PETRA GEOTECHNICAL INC. 27620 Commerce Center Dr. Ste. 103 Temecula, CA 92590 Tel: (909) 699.6193 Fax: (909) 699-6197 Petrate@jbm.net \ I ,. I . . . . . . . . . . . . . I . I RICHMOND AMERICAN HOMES TRs 23143-2, -3 & -4/Crowne Hill Phase I June 28, 1999 J.N.444-98 Page 2 REGULATORY COMPLIANCE Removal and recompaction of low-density surface soils, processing of the exposed bottom surfaces or placement of compacted fill under the purview of this report have been completed under the observation of and with selective testing by Petra. Earthwork and grading operations were performed in accordance with ,the recommendations presented in the grading-plan review report (see References) and the grading cod~ of the County of Riverside and the City of Temecula, California. Continued monitoring of Lots 12 through 14 of Tract 23143-4 is recommended until at least the end of July 1999, before construction begins on these lots. The completed earthwork has been reviewed and is considered adequate for the construction now planned. On the basis of our observations and 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 expressed or implied. ENGINEERING GEOLOGY General Geologic conditions exposed during the process of grading were frequently observed and mapped by Petra's geologic staff. Geolo!!ic Units Geologic conditions observed onsite were generally as anticipated and described in the preliminary geologic report for the site by Petra and others (see References). Removal bottoms and subdrain excavations were geologically mapped by a Petra geologist. The site consisted of an east-west-trending complex of highlands, comprised of Pauba formational sandstone and younger Quaternary alluvial-filled valleys. All unsuitable alluvial soils were removed to expose competent bedrock of the Pauba Formation. -z., ~ ~ I I ,I I I I I I I I I I I I I I I I I RICHMOND AMERICAN HOMES TRs 23143-2, -3 & -4/Crowne Hill Phase I June 28, 1999 J.N.444-98 Page 3 The underlying Pauba formational sandstones generally consisted of sandy silts and coarse sands which were predominantly fine-grained, very well-indurated to cemented, laminated, moist and dense. Groundwater During overexcavations and subdrain excavations, no areas of subsurface water w,ere encountered. Faulting No faults were encountered during grading operations on the site. SUMMARY OF EARTHWORK OBSERVATIONS AND DENSITY TESTING Site Gearin!! and Grubbing Prior to grading, all grasses, weeds, brush and shrubs were stripped and removed from' the site. Clearing operations included the removal of all trash, debris and similar unsuitable materials. Ground Preparation All deposits of existing artificial-fill materials and low-density native soils were removed to underlying bedrock. The removals varied from approximately 5 to 25 feet below original grades. Prior to placing fill, the exposed bottom surfaces were scarified. to depths of 6 to 8 inches, watered as necessary to achieve at or slightly above optimum moisture conditions, then recompacted in-place to a minimum relative compaction of 90 percent. ~ ~ ~ I II I I I I I I I I I I I I I I I I I I RICHMOND AMERICAN HOMES TRs 23143-2, -3 & -4/Crowne Hill Phase I June 28, 1999 J.N.444-98 Page 4 Toe-of-fill-slope keys were placed at the base of all fill slopes. Fill keys were excavated into competent native materials with a minimum slope of 2 percent to the heel of the key. Disposal of Oversize Rock Oversize materials were not encountered during the rough-grading operations for these lots. Cut/FiIl Transition Lots Cut/fill transition lots were eliminated due to overexcavation of the cut portion of the transition lots. The removals within the cut portion extended to depths of approximately 3 to 5 feet below finish grades. Cut Lots Some building pads and slopes within cut lots were cut to grade, geologically mapped and determined to be adequate to provide uniform support for the proposed residences and improvements without remediation. Fill Placement and Testing Fill materials consist of on site soils. All fills were placed in lifts restricted to approximately 6 to 8 inches in maximum thickness, watered as necessary to achieve near optimum moisture conditions, then compacted in-place to a minimum relative compaction of 90 percent by rolling with a D8 or D9 bulldozer, 834 rubber-tired bulldozer or loaded scrapers. The maximum verticil! depth of fill placed within the subject lots as a result of grading is approximately 48 feet. Field density and moisture content tests were performed in accordance with ASTM Test Methods D2922 and D3017 (nuclear gauge). Occasional field density tests were \ ~ ~ I I I I I I I I I I II I II I I I I I I RICHMOND AMERICAN HOMES TRs 23143-2, -3 & -4/Crowne Hill Phase I June 28, 1999 J.N.444-98 Page 5 also performed in accordance with ASTM Test Method Dl556 (sandcone). Test results are presented on Table I (attached) and test locations are shown on the enclosed rough-grading plans (Plates 1 through 4). 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 verify that the specified moisture content and minimum required relative compaction of 90 percent had been achieved. At least one in-place density test was taken for each 1,000 cubic yards of fill placed and/or for each 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 required minimum relative compaction of 90 percent, the approximate limits of the substandard fill were established. The substandard area was then reworked. Visual classification of earth materials in the field was the basis for determining if the maximum dry density value, summarized in a following section, was applicable for each given density test. One-point checks were performed to supplement visual classification. Fill-Slope Construction All fill slopes were constructed at a maximum ratio of 2: 1 (horizontal:vertical [h:v D. Maximum fill-slope height is approximately 25 feet located on Lot 11 of Tract 23143-4. Final surface compaction on the fill slopes was achieved by overfilling and backrolling the slopes during construction and then trimming to the compacted inner core or by backrolling the slope with a sheepsfoot roller. ,/I ~ ~ ~ I II I I I I I I I I II I I :1 I I I I I RICHMOND AMERICAN HOMES TRs 23143-2, -3 & -4/Crowne Hill Phase I June 28, 1999 J.N.444-98 Page 6 Deep-Fill Monitoring Settlement of the deep-fill areas encompassing Lots 12 through 14 of Tract 23143-4 is currently in progress using near-surface monuments established on Lot 13 (Monument No. SM-13). This settlement monument was installed after the completion of rough grading. Monitoring began on May 26, 1999, and is continuing. The monitoring is conducted by Robert'Bein William Frost & Associates, the project civil engineer. The monument is monitored for both vertical and lateral movement. The monitoring data to date indicates monument No. SM-13 has showed no lateral movement and vertical movement is 0.01:t foot (0.12:t inch). Petra recommends continued monitoring until at least the end of July 1999, to determine if fill settlement has stabilized within these lots. Subdrains , Following clean-outs to competent bedrock, subdrains were installed in the primary drainage courses. The subdrains were designed to mitigate the potential build-up of hydrostatic pressures below compacted fills due to infiltration of surface waters. Lot Summarv A summary of the cut, fill and transition lots onsite with the maximum depth of fill is provided in Table II. TABLE II Tract 23143-2 17 18 T T 15 13 ~ tti ~ I I RICHMOND AMERICAN HOMES June 28, 1999 TRs 23143-2, -3 & -4/Crowne Hill Phase I J.N. 444-98 I Page 8 I I Tract 23143-4 I F 10 2 T 8 I 3 C 4 C I 5 T 6 6 T 6 I 7 T 6 I 8 T 3 9 C 3 I 10 C 11 T 35 , 'I 12 F 53 ! 13 F 58 :1 14 F 52 I 15 T 42 I 16 T 31 ,I 17 T 30 I I I 40 I ~. .~ II II I I I I I I I I I I I I I I I I I RICHMOND AMERICAN HOMES TRs 23143-2, -3 & -4/Crowne Hill Phase I June 28, 1999 J.N.444-98 Page 9 LABORATORY TESTING Maximum Drv Density Maximum dry density and optimum moisture content for the major soil types observed during grading were determined in our laboratory in accordance with ASTM Test Method D1557-91. Pertinent test values are summarized in Appendix A. , Expansion Index Test 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 the 1997 Uniform Building Code (UBC) Standard 18-2. Test results . are summarized in Appendix A. Atterber!! Limits Liquid limit, plastic limit and plasticity index of soils was performed on selected samples of onsite soils which had expansion indices greater than 20 in accordance with ASTM Test Method D4318-93. Test results are summarized in Appendix A. Soluble Sulfate Analvses Water-soluble sulfate contents were also determined for representative samples of soil existing at or near pad grade of the subject lots in accordance with California Test Method No. 417. These tests resulted in negligible sulfate contents of less than 0.0 I percent. Test results are summarized in Appendix A. "- ~. ~ II I I I I I I I I I II ! '. I II !I I I . I RICHMOND AMERICAN HOMES TRs 23143-2, -3 & -4/Crowne Hill Phase I June 28, 1999 J.N.444-98 Page 10 POST-GRADING CONSIDERATIONS Landscaping and Maintenance of Graded Slopes The fill slopes are comprised of granular, relatively cohesionless soils and, unless mitigation measures are taken, the slopes will be subject to a low to moderate degree of surficial erosion, raveling and possible slumping during periods of heavy rainfall. I The fill slopes should be landscaped with a deep-rooted (4 to 5 feet deep), drought- resistant, woody plant species. To provide temporary slope protection while the woody materials mature, the slopes should be planted with a herbaceous plant species that will mature in one season or provided with some other protection, such as jute matting or polymer covering. The temporary protection should be maintained until the woody material has become fully mature. A landscape architect should be consulted to determine the most suitable plant materials and irrigation requirements. To mitigate future surficial erosion and slumping, a permanent slope-maintenance program should be initiated. Proper slope maintenance must include regular care of drainage- and erosion-control provisions, rodent control, prompt repair of leaking irrigation systems and replacement of dying or dead plant materials. The irrigation system should be'designed and maintained to provide a constant moisture content in the soils. Overwatering, as well as overdrying, of the soils can lead to surficial erosion and slumping. Homeowners should be advised of the potential problems that can develop when drainage on the pads and slopes is altered in any way. Drainage can be altered due to the placement of fill and construction of garden walls, retaining walls, walkways, patios, swimming pools and planters. \() =& ~ I I I I I I I I I I I I I I I I " I I RICHMOND AMERICAN HOMES TRs 23143-2, -3 & -4/Crowne Hill Phase I June 28, 1999 J.N.444-98 Page 11 Pad Drainal!e Drainage on the lots should be designed to carry surface water away from all graded slopes and structures. Pad drainage should be designed for a minimum gradient of I percent with drainage directed to the adjacent streets. After dwellings are constructed, positive drainage away from the structures and slopes should be provided on the lots by means of earth swales, sloped concrete flatwork and area drains. Utili tv Trenches All utility-trench backfill within street right-of-ways, utility easements, under sidewalks, driveways and building-floor slabs and within or in proximity to slopes, should be compacted to a minimum relative compaction of 90 percent. Where on site soils are utilized as backfill, mechanical compaction will be required. Density testing, along with probing, should be performed by a Petra representative to verify adequate compaction. Excavations for trenches that exceed 4 feet in depth should be laid-back at a maximum gradient of 1: 1 (h:v). For deep trenches with vertical walls, backfills should be placed in lifts no greater than 2 feet in thickness and then mechanically compacted with a hydra-hammer, pneumatic tampers or similar equipment. For deep trenches with sloped walls, backfill materials should be placed in lifts no greater than 8 inches and then compacted by rolling with a sheepsfoot tamper or similar equipment. As an alternative for shallow trenches (18 inches or less in depth) where pipe may be damaged by mechanical compaction equipment, such as under building-floor slabs, imported clean sand having a sand equivalent of 30 or greater may be utilized and jetted or flooded into place. No specific relative compaction will be required; however, observation, probing and, if deemed necessary, testing should be performed. \\ tti ~ I I I I I I I I I I I I I I I I I I I RICHMOND AMERICAN HOMES TRs 23143-2, -3 & -4/Crowne Hill Phase I June 28, 1999 J.N.444-98 Page 12 To avoid point-loads and subsequent distress to asbestos, clay, cement or plastic pipe, imported sand bedding should be placed at least 1 foot above all pipe in areas where excavated trench materials contain significant oversize rock. Sand-bedding materials should thoroughly jetted prior to placement of backfill. FOUNDATION DESIGN RECOMMENDATIONS ' General Based on our observations during grading and field and laboratory testing, the preliminary foundation design recommendations presented in our geotechnical investigation report (see References) are considered applicable for the subject lots. The recommendations are presented in the following sections of this report. Allowable-Bearin~ Values An allowable-bearing value of 1,500 pounds per square foot (psf) may be used for continuous footings founded at a minimum depth of 12 inches below the lowest adjacent tinal grade in compacted fill materials. An allowable-bearing value of 1,800 pounds psf may be used for continuous footings founded at a minimum depth of 18 inches below the lowest adjacent final grade in compacted fill materials. Recommended allowable-bearing values include both dead and live loads and may be increased by one-third for short-duration wind and seismic forces. Settlement Based on the above bearing values and maximum depth of fill, a total settlement of footings is expected to be less than 1 inch and differential settlement less than one-half of the total settlement. It is anticipated that the majority of the settlement will occur during or shortly following the completion of construction as the loads are applied. \~ ~ ~ I I I I I I I I I I I I I I I I I ,I I RICHMOND AMERICAN HOMES TRs 23143-2, -3 & -4/Crowne Hill Phase I June 28, 1999 J.N.444-98 Page 13 Lateral Resistance A passive earth pressure increasing at the rate of 250 pounds psf per foot of depth, to a maximum value of 3,000 pounds per square foot, may be used to determine lateral bearing for building footings constructed on level ground. A coefficient of friction of _ 0.4 times the dead-load forces may also be used between concrete and the supporting soils to determine lateral-sliding resistance. An increase of one-third of the above values may also be used when designing for short-duration wind and seismic forces. Expansive Soil Conditions Laboratory test data indicate the foundation soils underlying the subject lots exhibit VERY LOW to VERY HIGH expansion potential, as classified in accordance with 1997 UBC Standard Test No. 18-2. Minimum design recommendations for footings and residential floor slabs for this condition are presep.ted below. However, additional slab thickness, footing size and/or reinforcement may be necessary for structural considerations, as determined by the project architect and/or structural engineer. A summary of the expansion test results and associated lots is provided in Appendix A. Results of our laboratory tests indicate Lots 60 through 63 of Tract 23143-2, Lot 27 of Tract 23143-3 and Lots 1 through 9 and Lots 11 through 17 of Tract 23143-4 exhibit a VERY LOW expansion potential as classified in accordance with 1997 UBC Table 18-I-B. Since the onsite soils exhibit expansion indices of less than 20, the design of slab-on-ground foundations is exempt from the procedures outlined in 1997 UBC Section 1815. Based on the above soil conditions, it is recommended that footings and floors be constructed and reinforced in accordance with the following minimum criteria. However, additional slab thickness, footing sizes and/or reinforcement should be provided as required by the project architect or structural engIneer. \~ ~ ~ I I I I I I I I I I I I I i ' I I I II RICHMOND AMERICAN HOMES TRs 23143-2, -3 & -4/Crowne Hill Phase I June 28, 1999 J.N.444-98 Page 14 . Footings - Exterior continuous footings may be founded at the minimum depths indicated in 1997 UBC Table l8-I-C (i.e. 12-inch minimum depth for one-story and 18- inch-minimum depth for two-story construction). Interior continuous footings for both one- and two-story construction may be founded at a minimum depth of 12 inches below the lowest adjacent grade. All continuous footings should have a'minimum width of 12 and 15 inches, for one- and two-story building, respectively, and should be reinforced with two NO.4 bars, one top and one bottom. Exterior pad footings intended for the support of roof overhangs, such as second story decks, patio covers and similar construction, should be a minimum of 24 inches square and founded at a minimum depth of 18 inches below the lowest adjacent final grade. No special reinforcement of the pad footings will be required. . Buildin~-Floor Slabs - Living-area concrete-floor slabs should be 4 inches thick and reinforced with either 6-inch by 6-inch, No.6 by No.6 welded-wire mesh (6x6-W2.9xW2.9); or with No.3 bars spaced a maximum of 24 inches on center, both ways. All slab reinforcement should be supported on concrete chairs or brick to ensure the desired placement near mid-depth. - Living-area concrete-floor slabs should be underlain with a moisture-vapor barrier consisting of a polyvinyl-chloride membrane such as 6-mil visqueen or equivalent. All laps within the membrane should be sealed, and at least 2 inches of clean sand be placed over the membrane to promote uniform curing of the concrete. - Garage-floor slabs should be 4 inches thick and should be reinforced in a similar manner as living-area floor slabs. Garage-floor slabs should also be poured separately from adjacent wall footings with a positive separation maintained with 3/8-inch-minimum, felt expansion-joint materials and quartered with weakened-plane joints. A 12-inch-wide grade beam founded at the same depth as adjacent footings should be provided across garage entrances. The grade beam should be reinforced with a minimum of two No.4 bars, one top and one bottom. I I ~ tti ~ I I I I I I I I I I II I I II I I I I I RICHMOND AMERICAN HOMES TRs 23143-2, -3 & -4/Crowne Hill Phase I June 28, 1999 J.N.444-98 Page 15 Presaturation of the subgrade soils below floor slabs will not be required; however, prior to placing concrete, the subgrade soils below all living-area and garage-floor slabs should be pre-watered to promote uniform curing of the concrete and minimize the development of shrinkage cracks. Results of our laboratory tests indicate onsite soils within Lots 20 through 22 and 57 through 59 of Tract 23143-2 and Lots 24 through 26 and Lots 99 through 102 of Tract 23143-3 exhibit a LOW expansion potential as classified in accordance with Table 18-I-B of the 1997 UBC. The 1997 UBC specifies that slab-on-ground foundations (floor slabs) on soils with an expansion index greater than 20 require special design considerations in accordance with 1997 UBC Section 1815. The design procedures outlined in 1997 UBC Section 1815 are based on a plasticity index of the different soil layers existing within the upper 15 feet of the building site. Based on subsurface stratigraphy and distribution of the different soil types, we have calculated an effective plasticity index of 15 in accordance with 1997 UBC Section 1815.4.2. The design and construction recommendations that follow are based on the above soil conditions and may be considered for minimizing the effects of slightly expansive soils. These recommendations have been based on the previous experience of Petra on projects with similar soil conditions. Although construction performed in accordance with these recorrunendations has been found to minimize post-construction movement and/or cracking, they generally do not positively mitigate all potential effects of higWy expansive soil. The owner, architect, design civil engineer, structural engineer, and contractors must 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. \~ tti ~ I I I I I I I I I I ;1 , 'I I II I I I I I RICHMOND AMERICAN HOMES TRs 23143-2, -3 & -4/Crowne Hill Phase I June 28, 1999 J.N.444-98 Page 16 . Footings - Exterior continuous footings may be founded at the minimum depths indicated in 1997 UBC Table 18-I-C (i.e., 12-inch minimum depth for one-story and 18- inch minimum depth for two-story construction). Interior continuous footings for both one- and two-story construction may be founded at a minimum depth of 12 inches below the lowest adjacent grade. All continuous footings should have a minimum width of 12 and 15 inches, for one- and two-story buildings,' respectively, and should be reinforced 'with two No.4 bars, one top and one bottom. Exterior pad footings intended for the support of roof overhangs, such as second story decks, patio covers and similar construction, should be a minimum of 24 inches square and founded at a minimum depth of 18 inches below the lowest adjacent final grade. The pad footings should be reinforced with No.4 bars spaced a maximum of 18 inches on centers, both ways, near the bottom-third of the footings. . Building: Floor Slabs The project architect or structural engineer should evaluate minimum floor slab thickness and reinforcement in accordance with 1997 UBC Section 1815 based on an effective plasticity index of 15. Unless a more stringent design is recommended by the architect or the structural engineer, we recommend a minimum slab thickness of 4 inches for both living-area and garage-floor slabs, and reinforcing consisting of either 6-inch by 6-inch, No.6 by NO.6 welded-wire mesh (6x6-W2.9xW2.9) or No.3 bars spaced a maximum of 18 inches on centers, both ways. All slab reinforcement should be supported on concrete chairs or brick to ensure the desired placement near mid-height. Living-area concrete-floor slabs should be underlain with a moisture-vapor barrier consisting of a polyvinyl-chloride membrane such as 6-mil visqueen or equivalent. All laps within the membrane should be sealed, and at least 2 inches of clean sand be placed over the membrane to promote uniform curing of the concrete. - Garage-floor slabs should also be poured separately from adjacent wall footings with a positive separation maintained with 3/8-inch-minimum, felt expansion- joint materials and quartered with weakened-plane joints. A l2-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 a minimum of two No.4 bars, one top and one bottom. \~ tti ~ I I I I I I I I I I I I I I I I I II I I RICHMOND AMERICAN HOMES TRs 23143-2, -3 & -4/Crowne Hill Phase I June 28, 1999 J.N.444-98 Page 17 Prior to placing concrete, the subgrade soils below all living-area and garage- floor slabs should be pre-watered to achieve a moisture content that is at least equal to or slightly greater than optimum-moisture content. This moisture content should penetrate to a minimum depth of 12 inches into the subgrade soils. Results of our laboratory tests indicate soils within Lots 17 through 19 of Tract 23143-2; Lots 22 and 23 of Tract 23143-3, and; Lot 10 of Tract 23143-4 exhibit a MEDIUM expansion potential as classified in accordance with 1997 UBC Table 18-I-B of. The 1997 UBC specifies that slab-on-ground foundations (floor slabs) on soils with an expansion index greater than 20 require special design considerations in accordance with 1997 UBC Section 1815. The design procedures outlined in 1997 UBC Section 1815 are based on a plasticity index of the different soil layers existing within the upper 15 feet of the building site. Based on subsurface stratigraphy and distribution of the different soil types, we have calculated an effective plasticity index of 17 in accordance with 1997 UBC Section 1815.4.2. The design and construction recommendations that follow are based on the above soil conditions and may be considered for minimizing the effects of moderately expansive , soils. These recommendations have been based on the previous experience of Petra on projects with similar soil conditions. Although construction performed in accordance with these recommendations has been found to minimize post-construction movement and/or cracking, they generally do not positively mitigate all potential effects of highly " expansive soil. The owner, architect, design civil engineer, structural engineer, and contractors must 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. ~\\ ~ ~ I I I I I I I I I I II RICHMOND AMERICAN HOMES TRs 23143-2, .3 & -4/Crowne Hill Phase I June 28, 1999 J.N.444-98 Page 18 . Footings - Exterior continuous footings for both one- and two-story construction should be founded at a minimum depth of 18 inches below the lowest adjacent final grade. Interior continuous footings may be founded at a minimum depth of 12 inches below the lowest adjacent grade for both one- and two-story construction.. All continuous footings should have a minimum width of 12 and 15 inches, for one- and two-story buildings, respectively, and should be reinforced with two No.4 bars, one top and one bottom. - Exterior pad footings intended for the support of roof overhangs, such as second story decks, patio covers and similar construction, should be a minimum of 24 inches square and founded at a minimum depth of 18 inches below the lowest adjacent final grade. The pad footings should be reinforced with No.4 bars spaced a maximum of 18 inches on centers, both ways, near the bottom-third of the footings. . Building Floor Slabs :1 I I I I I I I - The project architect or structural engineer should evaluate minimum floor slab thickness and reinforcement in accordance with 1997 UBC Section 1815 based ,on an effective plasticity index of 17. Unless a more stringent design is ,recommended by the architect or the structural engineer, we recommend a minimum slab thickness of 4 inches for both living-area and garage-floor slabs and reinforcing consisting of No.3 bars spaced a maximum of 18 inches on centers, both ways. All slab reinforcement should be supported on concrete chairs or brick to ensure the desired placement near mid-height. - Living-area concrete-floor slabs should be underlain with a moisture-vapor barrier consisting of a polyvinylcchloride membrane such as 6-mil visqueen or equivalent. All laps within the membrane should be sealed, and at least 2 inches of clean sand be placed over the membrane to promote uniform curing of the concrete. Garage-t1oor slabs should also be poured separately from adjacent wall footings with a positive separation maintained with 3/8-inch-minimum, felt expansion- joint materials and quartered with weakened-plane joints. A 12-inch-wide grade beam founded at the same depth as adjacent footings should be provided across garage entrances. The grade beam should be reinforced with a minimum of two NO.4 bars, one top and one bottom. \'C> tti. ~ I I I I I I I I I I I I I I I I I I I RICHMOND AMERICAN HOMES TRs 23143-2, -3 & -4/Crowne Hill Phase I June 28, 1999 J.N.444-98 Page 19 Prior to placing concrete, the subgrade soils below all 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 minimum depth of 18 inches into the subgrade soils. Results of our laboratory tests indicate onsite soils within Lots 60 through 63 of Tract 23143-2 and Lots 103 through 105 of Tract 2,3143-3 exhibit a HIGH to VERY HIGH expansion potential as classified in accordance with Table 18-I-B of the 1997 UBC. The 1997 UBC specifies that slab-on-ground foundations (floor slabs) on soils with an expansion index greater than 20 require special design considerations in accordance with 1997 UBC Section 1815. The design procedures outlined in 1997 UBC Section 1815 are based on a plasticity index of the different soil layers existing within the upper 15 feet of the building site. Based on subsurface stratigraphy and distribution of the different soil types, we have calculated an effective plasticity index of 24 for the High potential and 35 for the Very High potential in accordance with 1997 UBC Section 1815.4.2. The design and construction recommendations that follow are based on the above soil conditions and may be considered for minimizing the effects of highly expansive soils. These recommendations have been based on the previous experience of Petra on projects with similar soil conditions. Although construction performed in accordance with these recommendations has been found to minimize post-construction movement and/or cracking, they generally do not positively mitigate all potential effects of highly expansive soil. The owner, architect, design civil engineer, structural engineer, and contractors must 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. \'\ tti ~ I I I I I I I I I I I I I I I I I I I RICHMOND AMERICAN HOMES TRs 23143-2, -3 & -4/Crowne Hill Phase I June 28, 1999 J.N. 444-98 Page 20 . Footings All exterior footings for both one-story and two-story construction should be founded a minimum depth of 24-inches below the lowest adjacent final grade. Interior continuous footings may founded at a minimum depth of 18 inches below the lowest adjacent final grade. All continuous footings should have a minimum width of 12 and 15 inches, 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 ofroof overhangs, such as second story decks, patio covers and similar construction, should be a minimum of 24 inches square and founded at a minimum depth of 24 inches below the lowest adjacent final grade. The pad footings should be reinforced with No.4 bars spaced a maximum of 18 inches on centers, both ways, near the bottom-third of the footings. . Building Floor Slabs The project architect or structural engineer should evaluate minimum floor-slab thickness and reinforcement in accordance with 1997 UBC Section 1815 based on an effective plasticity index of 24 and 35 for High and Very High, respectively. Unless a more stringent design is recommended by the architect or the structural engineer, we recommend a minimum slab thickness of 5 inches for both living-area and garage-floor slabs and reinforcing consisting of No.3 bars spaced a maximum of 18 inches on centers, both ways. All slab reinforcement should be supported on concrete chairs or brick to ensure the desired placement near mid-height. - Living-area concrete-floor slabs should be underlain with a moisture-vapor barrier consisting of a polyvinyl-chloride membrane such as 6-mil vis queen or equivalent, placed on top of a 4-inch thick sand or gravel base. All laps within the membrane should be sealed and an additional 2 inches of clean sand be placed over the membrane to promote uniform curing of the concrete. - Garage-floor slabs should have a minimum slab thickness of 5 inches on a 4- inch-thick sand base and should be reinforced in a similar manner as living-area floor slabs. Garage-floor slabs should also be poured separately from adjacent wall footings with a positive separation maintained with 3/8-inch-minimum, felt expansion-joint materials and quartered with weakened-plane joints. A 12-inch- wide by 24-inch-deep grade beam founded at the same depth as adjacent 19 ~ ~ I I I I I I I I I I I I I I I I I I I RICHMOND AMERICAN HOMES TRs 23143-2, -3 & -4/Crowne Hill Phase I June 28, 1999 J.N. 444-98 Page 21 footings should be provided across garage entrances. The grade beam should be reinforced with a minimum of four No.4 bars, two top and two bottom. - Prior to placing concrete, the subgrade soils below all living-area and garage- floor slabs should be presoaked to achieve a moisture content that is 5 percent or greater above optimum moisture content. This moisture content should penetrate to a minimum depth of 24 inches into the subgrade soils. Presaturation of the subgrade soils will promote uniform curing of the concrete and minimize the development of shrinkage cracks. Soluble Sulfates Laboratory test data indicate soils within the subject lots have a negligible soluble- sulfate content. As such, concrete in contact with soil may utilize Type I or II Portland cement. Structural Setbacks Footing setbacks of residential structures from property lines and from the tops and toes of the engineered fill slopes should conform to the minimum setback requirements of 1997 UBC Chapter 18. Structural setbacks of retaining walls, swimming pools and spas proposed on or near the tops of descending slopes should be analyzed separately. Footin!! Observations All building-footing trenches should beobserved by a Petra representative to verify that they have been excavated into competent bearing soils and to depths conforming to 1997 UBC Chapter 18. The foundation excavations should be observed prior to the placement forms, reinforcement or concrete. The excavations should be trimmed neat, level and square. All loose, sloughed or moisture-softened soil and/or any construction debris, should be removed prior to placing concrete. 1>' tti ~ I I I I I I I I I I I I I I I I I I I RICHMOND AMERICAN HOMES TRs 23143-2, -3 & -4/Crowne Hill Phase I June 28, 1999 J.N.444-98 Page 22 Excavated soils derived from footing and utility-trench excavations should not be placed in slab-on-grade areas unless the soils are compacted to at least 90 percent of maximum dry density. RETAINING-WALL DESIGN RECOMMENDATIONS Allowable-Bearinl,l Capacity and Lateral Rest Footings for retaining walls may be designed using the allowable-bearing capacity and lateral-resistance values recommended for building footings; however, when calculating passive resistance, the upper 6 inches of the footings should be ignored in areas where the footings are not covered with concrete flatwork. Active and At-Rest Earth Pressures An active lateral-earth pressure equivalent to a fluid having a density of 35 (very low), " 45 (medium) and 50 (high) pounds per cubic foot should be used for design of cantilevered walls retaining a drained, level backfill. Where the wall backfill slopes upward at 2: I (h:v), the above values should be increased to 53 (very low), 75 (medium) and 87 (high) pounds per cubic foot. The above values an:! for onsite soils which exhibit very low and medium expansions and are placed behind the walls a minimum horizontal distance equal to one-half the wall height. All retaining walls should be designed to resist any surcharge loads imposed by other nearby walls or structures in addition to the above active earth pressures. Drainage Perforated pipe-and-gravel subdrains should be installed behind all retaining walls to prevent entrapment of water in the backfill. Perforated pipe should consist of 4-inch- minimum-diameter PVC Schedule 40 or ABS SDR-35 with the perforations laid- down. The pipe should be encased in a I-fool-wide column of 0.75- to 1.5-inch, open- v>- tti ~ I I I I I I I I I I I I I I I il , I !I I I RICHMOND AMERICAN HOMES TRs 23143-2, -3 & -4/Crowne Hill Phase I June 28, 1999 J.N.444-98 Page 23 graded gravel extending above the wall footing to a minimum height of 1.5 feet above the footing or to a height equal to one-third the wall height, whichever is greater. The gravel should be completely wrapped in filter fabric consisting of Mirafi 140N or equivalent. Solid outlet pipes should be connected to the subdrains and routed to a suitable area for discharge of accumulated water. Weepholes, if used, should be 3-inch-minimum diameter and provided at maximum intervals of 6 feet along the walls. Open, vertical masonry joints should be provided at 32-inch-minimum intervals. One-cubic-foot of gravel 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 should consist of Mirafi 140N or equivalent. Waterproofin!! The portions of retaining walls supporting backfill should be coated with an approved waterproofing compound or covered with similar material to inhibit infiltration of moisture through the walls. Retaining-Wall Backfill All retaining-wall backfill should be placed in 6- to 8-inch-maximum horizontal lifts, watered or air-dried as necessary to achieve near optimum moisture conditions and compacted in-place to a minimum relative colllpaction of 90 percent. Flooding or jetting of backfill materials should be avoided. A Petra representative should verify adequate compaction of all backfill. MASONRY GARDEN WALLS The footings should also be reinforced with a minimum of two No.4 bars, one top and one bottom. In order to mitigate the potential for unsightly cracking, positive ,?{ ~ ~ I I I I I I I I I I I I I I I I I I I RICHMOND AIVIERICAN HOMES TRs 23143-2, -3 & -4/Crowne Hill Phase I June 28, 1999 J.N.444-98 Page 24 separations should also be provided in the garden walls at a maximum horizontal spacing of 20 feet. These separations should be provided in the blocks only and not extend through the footing. The footing should be poured monolithically with continuous rebars to serve as an effective "grade beam" below the wall. In areas where garden walls may be proposed on or near the tops of descending slopes, the footings should be deepened such that a minimum horizontal clearance of 7 feet is maintained between the outside bottom edges of the footings and the face of the slope. 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 all footing trenches when first excavated to verify adequate depth and competent soil-bearing conditions. Re-observe all footing trenches, if necessary, if trenches are found to be excavated to inadequate depth and/or found to contain significant slough, saturated or compressible soils. . Retaining-Wall Construction - Observe all footing trenches when first excavated to verify adequate depth and competent soil-bearing conditions. Re-observe all footing trenches, if necessary, if trenches are found to be excavated to inadequate depth and/or found to contain significant slough, saturated or compressible soils. ~ ttA ~ I I I I I I I I I I I I I I I I I I II RICHMOND AMERICAN HOMES TRs 23143-2, -3 & -4/Crowne Hill Phase I June 28, 1999 J.N.444-98 Page 25 - Observe and verify proper installation of subdrainage systems prior to placing wall backfill. Observe and test placement of all wall backfill. . Masonry-Garden Walls Observe all footing trenches when first excavated to verify adequate depth and competent soil-bearing conditions. Re-observe all footing uenches following removal of any slough and/or saturated soils and re-excavate to proper depth. . Exterior Concrete-Flatwork Construction - Observe and test subgrade soils below all concrete-flatwork areas to verify adequate compaction and moisture content. . Utility-Trench Backfill - Observe and test placement of all utility-trench backfill. . Re-Grading - Observe and test placement of any fill to be placed above or beyond the finish grades shown on the grading plans. /' 1;-"0 tti ~ I I I I I I I I I I I I I I I I I II i I RICHMOND AMERICAN HOMES TRs 23143-2, -3 & -4/Crowne Hill Phase I June 28, 1999 J.N.444-98 Page 26 This opportunity to be of service is sincerely appreciated. Please call if you have any questions pertaining to this report. Respectfully submitted, Siama r Principal En RCE 36641 Attachments: Table I - Summary of Field Density Tests References Plates I through 4 - Density Test Location Map (in pocket) Appendix A - Laboratory Test Criteria/Laboratory Test Data Distribution: (6) Addressee '* ~ ~ I !. I II m I I I I m I m I I II U U U I I TABLE I Field Density Test Results ......,......,..,..~~.........., ........, r, r".... .,....,..,..,....,....,............,......,..,........,............,..................~,~f, T,i,.,..,........ ......~.~.............,............,............,Ir,....,f,l,...r, r,.......,JS,i,IIIII,.,,~~,...~,T, fl~'ilI~~lH~; , ',', DATE ""NO., , ',' "',,' .'.',' ,.",LOCATION ",',",",.'" "',", "'" "',',' tn' ,",,' ','," ',",' ", (%.' ",...."" (,pc"'..J%'.,,",,,,,,E ' .- ..... _.-'_. . . ,', .. , .', , .", '.'....,.,:,::,. :';"'.';"';'.. :'..'. .. .....:.:.; .... ._.......,.,.._..:.,_..".;:.,.,. ...... :'.':_. , . _ , , . ......., ',,_,.:.. :__,_ _;_,_ ,__,_ .__,_,,_','_" :...........,. """:':'-':"_;''':''''':';':''';':'''':'\:;_. .:_.],:-:;.::-..... .. ..... .... ....;._., ":,_', .,..'1.:'- ';":"::':";";";":":";":":'-'-" - ."....~I::;:;::':: ,:;,;:,:::-:-,::-:::'\}!:f:::-J :,:,.::.:.:.;;::.::.:,:.:::(!:~:!i:!:::_,.., ,0:-.:. .;.;.:." o 1/06/99 201 Lot 19 1214.0 o 1/06/99 201A RTNo. 201 01/10/99 251 TR 23 1 43-2/Lot 20 1218.0 01/11/99 264 TR 23143-2/Lot 19 1226.0 01/11/99 266 TR 23 1 43-2/Lot 24 1230.0 o 1/1lI99 268 TR 23 1 43-2/Lot 21 1229.0 01/11/99 269 TR 23143-2/Lot.t9 1229.0 01/12/99 284 TR 23143-2/Lot 21 I 1232.0 01/12/99 285 TR 23 1 43-2/Lot 19 1232.0 01/18/99 310 TR 23143-2/Lot 18 1234.0 01/18/99 317 TR 23143-2/Lot 21 1232.0 01/18/99 330 TR 23143-3/Lot 19 1233.0 01/20/99 343 TR 23143-3/Lot 18 1238.0 02/16/99 872 TR 23143-4/Lot I 1257.0 02/16/99 873 TR 23 I 43-4/Lot I 1258.0 02/16/99 874 TR 23143-4/open space 83/Lot 14 1235.0 02/16/99 875 TR 23143-4/open space 83/Lot 14 1236.0 02/16/99 894 TR 23143-4/open space 83/Lot 14 1238.0 02/16/99 895 RT No. 894 02/17/99 947 TR 23 I 43-4/Lot t 6 1244.0 02/17/99 948 TR 23143-4/Lot 16 1240.0 02/17/99, 978 TR 23143-3/open space 83/Lot 13 t238.0 02/1 7/99 979 TR 23143-3/open space 83/Lot 13 1237.0 02/18/99 1012 TR 23143-4/Lot 15 1243.0 02/18/99 1013 TR 23143-4/Lot 15 1244.0 02/22/99 1079 TR 23143-4/Lot 14 1246.0 02/22/99 1092 TR 23143-4/Lot 14 1247.0 02/22/99 1093 RT No. 1092 02/22/99 1113 TR 23143-4/Lot 13 1246.0 02/23/99 1157 TR 23143-4/Lot 12 1249.0 02/23/99 1158 TR 23143-4/Lot 12 1250.0 02/23/99 1183 TR 23143-4/Lot 13 1249.0 02/23/99 1184 TR 23143-4/Lot 13 1250.0 02/23/99 1193 TR 23 1 43-4/Lot 14 1248.0 02/24/99 1216 TR 23143-4/Lot 15 1252.0 02/24/99 1217 TR 23t43-4/Lot 14 1253.0 02/24/99 1218 TR 23 1 43-4/Lot 12 1254.0 02/24/99 1219 TR 23 I 43-4/Lot II 1255.0 02/25/99 1266 TR 23143-4/Lot 14 1254.0 02/25/99 1267 TR 23143-4/Lot 14 1255.0 02/25/99 1277 TR 23143-4/Lot 70 slope 1283.0 02/25/99 1282 TR 23 I 43-4/Lot 13 1243.0 02/25/99 1283 TR 23143-4/Lot 13 1314.0 PETRA GEOTECHNICAL, INC J. N. 444-98 11.5 114.0 88 B 12.5 122.5 95 B 8.5 119.0 90 D 8.0 ,116.5 90 B 11.5 124.0 93 D 11.5 120.0 90 D 14.5 ' 117.0 90 E 13.5 125.0 93 D 14.0 117.5 90 E 13.5 121.0 91 G 12.5 122.5 92 G 11.0 118.0 91 B 11.5 119.5 92 B 8.0 120.0 91 F 11.0 118.0 90 M 10.5 123.5 93 F 11.5 119.0 90 M 17.5 106.0 81 I 10.0 121.0 91 F 12.5 120.0 90 F 12.5 107.0 92 Q 9.5 117.0 93 I 9.5 122.0 92 F 12.5 113.0 90 N 14.5 113.5 90 N 12.5 121.5 91 F 14.0 115.0 88 L 12.5 117.5 90 L 11.0 118.5 91 L 13.5 118.0 93 I 13.5 114.5 91 I 12.5 .118.5 91 L 14.0 118.0 91 L 12.5 120.5 91 F 13.0 114.0 91 S 14.0 118.0 92 P 11.5 117.0 91 P 13.5 117.5 92 P 12.5 113.0 90 S 13.0 108.5 90 R 10.0 116.5 90 10.5 112.5 90 S 13.0 116.5 93 S JUNE 28, 1999 ~1 TABLE T-I 1 . 10 o II I . . . . I I . . . . . ,. I I TABLE I Field Density Test Results 'T'E'S'T' ',. tttt:'.,.':',.:-,',_.:>. ,} .-,.......,.,.,..-.,.-..-.-.- .,.-.',-...............,',',",.,....,.._. DA'l1Ill," ........,',,',..-....-.--.-..-. .... ..... 02/25/99 02/25/99 03/09/99 03/09/99 03/09/99 03/09/99 03/09/99 03/1 0/99 03/1 0/99 03/10/99 03/11/99 03/12/99 03/12/99 03/15/99 03/15/99 03/16/99 03/16/99 03/17/99 03/17/99 03/18/99 03/18/99 03/18/99 03/18/99 03/19/99 03/19/99 03/19/99 03/19/99 03/19/99 03/19/99 03/22/99 03/22/99 03/22/99 03/22/99 03/22/99 03/22/99 03/22/99 03/23/99 03/23/99 03/23/99 03/23/99 03/23/99 03/23/99 03/23/99 03/23/99 ...'.....,...,.....~~,.....,........i..........................;I)i'ESW.ii ................................I................~~~;...,.,.....,.,...,.,.,..',....".....,',.,.,'.,~,..,..,"..,'",.,.,.,..,1,.....,...0,..,......,.,.,..',.,.,',','~,',',',...,'.."",',....",.,f"".,.,.,..),p..,.,.,'."'.,,',,,'..,R,..'.,',.,.'. ..,.."E,.,.".,.,..,..',..."..,.,,'.,'..,'.,',.,,'.,.."'...."p.',.,..."'.,..,.,',..,."E..".,,,.,,...,k,...,N..pi,..,C~,..,,"',I..,T,. ...-g.,.,.....M~~f!\!1..~~t!l1I1 I.N:~; i.....'.....,ii."...iiiJ'1QGATIQN ..'.' I IiII i..' (.fl)...i \'1.., "i.,.(It~),'i_.eiIi 1284 TR 23143-4/open space 83/Lot II 1253.0 13.0 116.0 92 S 1285 TR 23143-4/open space 83/Lot 11 1254.0 14.0 113.5 90 S 1663 TR 23143-4/Lot 7 1265.0 8.5 113.5 87 E 1664 TR23143-4/Lot7 1266.0 12.5 114.0 90 I 1665 RT No. 1663 13.0 115.5 89 E 1697 TR 23143-4/Lot 6 1269.0 10.5 115.0 89 W 1698 TR23 1 43-4/Lot6 1271.0 11.5 116.0 89 K 1717 RTNo.1665 t2.5 117.0 90 E 1764 TR23143-4/Lot 17 1269.0 10.5 118.0 92 P 1765 TR 23 1 43-4/Lot 17 1270.0 9.5 114.5 89 P 1772 RTNo.1765 11.0 116.0 91 P 1782 TR23143-4/Lot 15 1266.0 14.0 112.5 91 K 1783 TR23143-4/Lot 15 1267.0 11.0 115.0 91 I 1826 TR23143-4/Lot 13 1265.0 13.0 112.0 91 K 1827 TR 23143-4/Lot 13 1266.0 13.0 114.5 90 I 1831 TR23143-4/ManchesterCt 1270.0 ]5.5 115.0 92 S 1832 TR23143-4/ManchesterCt 1271.0 ]5.5 113.5 90 S 1854 TR 23143-4/Lot 14 1269.0 14.0 117.5 90 H 1855 TR23143-4/Lot 14 1270.0 14.0 119.0 91 H 1922 TR23143-4/LotI6adj 1273.0 14.0 112.0 91 K 1923 TR 23143-4/Lot 16 adj 1274.0 t3.5 110.5 92 R 1925 TR23143-4/LotI6adj 1276.0 13.5 1175, 90 H 1926 TR 23 1 43-4/Lot 16 adj 1275.0 13.0 114.5 90 J 1934 TR23143-4/Lot 14 1268.0 8.0 115.0 91 I 1935 TR 23143-4/Lot 14 1269.0 9.0 114.0 90 I 1940 TR23 I 43-4/Lot2 1279.0 8.5 105.5 86 J 1955 RTNo.1940 15.0 112.0 91 J 1956 TR 23 I 43-4/Lot I 1280.0 12.0 114.0 92 I 1957 TR 23 1 43-4/Lot 2 1279.0 12.5 115.5 90 P 1958 TR 23 1 43-4/Lot 1 1280.0 13.0 114.0 90 I 1980 TR 23 I 43-4/Lot 15 1274.0 10.5 123.0 93 F 1981 TR23143-4/Lot 14 1275.0 11.0 119.5 90 F 1982 TR 23 1 43-4/open space 83/Lot 12 1265.0 8.0 113.5 90 I 1983 TR23143-4/open space 83/Lot 12 1266.0 10.0 117.5 90 L 1984 TR 23143-4/Lot 2 1280.0 10.0 122.0 92 F 1985 TR23143-4/Lot2 1281.0 10.0 121.5 92 F 1992 TR 23143-4/Lot 11 1262.0 11.0 124.5 94 D 1993 TR23143-4/Lotlt 1264.0 12.0 116.5 90 B 1994 TR 23143-4/Lot 17 1281.0 10.0 117.0 90 L 1995 TR23143-4/Lot 17 1281.0 8.5 117.5 90 L 2002 TR23143-2/LotI9 1233.0 14.0 108.5 90 R 2011 TR 23143-4/Lot 1 1281.0 6.5 111.0 89 N 2012 TR 23 I 43-4/Lot I 1282.0 7.5 \13.5 9\ N 2014 RT No. 2011 7.0 113.0 90 N PETRA GEOTECHNICAL1 INC. J.N.444-98 JUNE 281 1999 -z2> TABLE T-I 2 I I I ,{IiJ.$$W ..,..I..'l'~~W.... ,DATENQ) I 03/23/99 2015 1/ 03/24/99 2025 II 03/24/99 2026 03/24/99 2027 I 03/24/99 2028 03/24/99 2033 03/24/99 2034 I 03/24/99 2035 03/24/99 2036 03/24/99 2043 I 03/24/99 2044 03/24/99 2045 03/24/99 2046 I 03/24/99 2051 03/24/99 2052 03/24/99 2053 I 03/24/99 2054 03/24/99 2055 03/24/99 2065 I 03/24/99 2066 03/24/99 2067 03/24/99 2068 I 03/25/99 2072 03/25/99 2073 03/25/99 2074 I 03/25/99 2075 03/25/99 2076 I 03/25/99 2077 03/25/99 2090 03/25/99 2091 I 03/25/99 2092 03/25/99 2093 03/25/99 2094 I 03/25/99 2095 03/25/99 2096 03/25/99 2097 I 03/25/99 2098 03/25/99 2099 03/25/99 210 I 03/26/99 2118 I 03/26/99 2119 03/29/99 2151 I 03/29/99 2152 03/29/99 2159 I TABLE I Field Density Test Results .wf!$WI ;J8QG~WiQN TR 23143-4/Lot 2 TR 23 I 43-4/Lot 14 TR 23143-4/Lot 14 TR 23 I 43-4/Lot 12 TR 23 I 43-4/Lot 12 TR 23 I 43-4/Lot 7 TR 23143-4/Lot 7 TR 23 I 43-2/Lot 58 TR 23143-2/Lot 58 TR23143-4/Lot 16 TR 23143-4/Lot 16 TR 23 I 43-4/Lot space 83 TR 23 1 43-4/Lot space 83 TR 23 I 43-4/Lot 5 TR 23143-4/Lot 5 TR 23143-4/Lot 7 TR 23143-4/Lot 7 RT No. 2018 TR 23143-4/Lot 12 TR 23143-4/Lot 13 TR 23143-4/Lot 15 TR23143-4/Lot IS TR 23143-4/Lot II TR23143-4/Lot 12 TR23143-4/Lot 16 TR 23143-4/Lot 15 TR 23143-2/Lot 57 TR 23143-2/Lot 57 TR 23143-4/open space 83 TR 23143-4/open space 83 TR 23143-4/Lot 16 TR 23143-4/Lot 15 TR 23143-4/Lot 5 TR 23 I 43-4/Lot 4 TR 23143-4/open space 83 TR 23143-4/open space 83 TR 23143-4/Lot 14 TR 23 I 43-4/Lot 14 RT No. 2035 TR 23143-2/Lot 58 TR 23143-2/Lot 58 TR 23 t43-2/Lot 57 TR 23143-2/Lot 57 TR 23143-4/Lot 15 "".."EL'E'V' " ."...."...,,-......., . :~::,):::;:':::::'::\::::}?::::::::?, .,': ,:: :'::,: "::,:~,-::: ,...,..--...........,...--..,......... . ....................................... ....."...."...............--..-..-.._,.. ,(ftyI 1283.0 1278.0 1279.0 1272.0 1273.0 1280.0 1281.0 1212.0 1213.0 1280.0 1281.0 1271.0 1272.0 1282.0 1281.0 1281.0 1282.0 1265.0 1266.0 1279.0 1280.0 1266.0 1267.0 1283.0 1282.0 1214.0 1215.0 1266.0 1267.0 1282.0 1283.0 1282.0 1283.0 1266.0 1267.0 1276.0 1277.0 1215.0 1216.0 1216.0 1217.0 1284.0 PEITRA GEOTECHNICAL, INC J. N. 444-98 J\!1l~i%!1l$~.P~N~~Cl'l1..g~~!..~~~M. I(%}I,...'.......(I.I..(p~t), ..II rtt4) I!Ir~rI,.. 11.0 117.5 91 L 7.5 112.5 90 S 9.5 109.5 91 R 10.5 120.0 92 L 9.5 116.0 93 S 12.0 117.0 91 P 12.5 114.5 91 J 18.0' 109.5 89 J 10.5 110.5 90 J 10.0 119.5 92 L 10.5 121.0 93 L 9.0 115.0 90 P 9.0 117.0 90 L 13.0 116.0 92 S 8.5 114.0 91 S 7.5 120.5 93 L 8.0 117.5 91 L 13.5 115.0 90 P 9.5 125.0 94 D 8.5 126.0 95 D 9.0 118.0 91 L 11.0 118.0 91 L 9.5 119.5 91 M 10.0 119.0 91 M 12.0 115.5 90 P 10.5 117.5 90 L 21.5 103.5 93X ,15.0 111.5 91 J 10.5 111.5 9t K 12.0 113.5 901 9.5 117.0 92 P 14.0 115.5 90 P 12.0 118.5 91 L 10.0 119.0 91 L 10.5 111.0 90 K 11.5 112.0 90N 9.0 117.5 94 S 10.5 116.0 92 S 13.0 108.5 90 R 16.0 111.5 91 K 15.0 113.5 91 N 14.5 115.5 91 I 16.5 113.5 90 I 9.0 117.0 91 P JUNE 28, 1999 TABLE T-I 3 'f' I II I """"'-"'---,-'-"'-,','" ....iiawiSJE pi\!!I! 03/29/99 I 03/29/99 03/29/99 03/29/99 I 03/29/99 03/29/99 03/29/99 I 03/29/99 03/29/99 03/29/99 I 03/29/99 03/29/99 03/29/99 I 03/29/99 03/29/99 I 03/30/99 03/30/99 03/30/99 03/30/99 I 03/30/99 03/30/99 03/30/99 I 03/30/99 03/30/99 I 03/30/99 03/30/99 03/30/99 I 03/30/99 03/30/99 03/30/99 I 03/30/99 03/30/99 03/30/99 I 03/30/99 03/30/99 03/30/99 I 03/31/99 03/3 1/99 04/01/99 I 04/01/99 04/01/99 04/0 1/99 I 04/01/99 04/0 1/99 I TABLE I Field Density Test Results ..."'.'.!Il"'E""".' ),:\(:-:::- _:_':Q:;:"';)~~, .....".........--.-. ..,',.....----.....," . .................. . NO;......... ..... ...........--.-- 2160 2161 2162 2169 2170 2171 2172 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2219 2220 2221 2222 2223 2224 2225 2232 2233 2234 2235 2236 2237 2261 2262 2278 2279 2280 2281 2286 2287 ........................II~lilll.......................................... " TR23143-4/Lot 15 TR23143-4/Lot 13 TR 23 1 43-4/Lot 13 TR 23143-4/Lot 14 TR 23 I 43-4/Lot 14 TR 23 I 43-4/Lot II TR 23143-4/Lot II TR 23143-2/Lot 18 TR 23143-2/Lot 18 TR 23143-4/open space 84/Lot 12 TR 23143-4/open space 84/Lot 12 TR 23143-4/Lot 15 TR 23143-4/Lot 15 TR 23143-2/Lot 19 TR 23 1 43-2/Lot 19 TR 23 1 43-4/Lot 6 TR 23143-4/Lot 7 TR23143-4/Lot 4 TR 23143-4/Lot 4 TR 23143-4/Lot 14 TR 23143-4/Lot 14 TR 23143-4/Lot II TR 23143-4/Lot 11 TR 23143-4/Lot II TR 23143-4/Lot 11 TR 23143-4/Lot 8 TR 23143-4/Lot 13 TR 23 1 43-4/Lot 13 TR 23143-2/Lot 20 TR 23 I 43-2/Lot 20 RTNo.2177 RTNo.2178 TR 23 1 43-2/Lot 19 TR 23143-2/Lot 19 TR 23143-4/Lot 12 TR 23143-4/Lot 12 TR 23143-2/Lot 21 TR 23 1 43-2/Lot 21 TR 23 I 43-2/Lot 17 TR 23143-2/Lot 17 TR 23143-2/Lot 20 TR 23 t43-2/Lot 20 RT No. 2281 TR 23143-2/Lot 20 PEITRA GEOTECHNICAL, INC. }.N.444-98 ~~I'I;i_I~irll,(1~~11Ir~'l.lIl, 1285.0 9.5 117.0 91 P 1276.0 9.5 115.5 90 P 1277.0 10.0 116.0 91 P 1280.0 12.0 115.0 90 P 1281.0 12.0 114.0 90 I 1271.0 13.5 114.0 90 I 1272.0 13.0 111.0 90 K 1232.0 17.0 102.5, 85 R 1234.0 17.0 103.0 85 R 1277.0 14.0 115.0 90 J 1275.0 8.0 120.0 92 L 1284.0 10.5 118.5 91 L 1285.0 11.0 111.0 90 J 1237.0 13.0 115.0 90 P 1238.0 12.5 115.5 90 P 1283.0 10.0 125.0 94 G 1288.0 9.0 126.5 95 G 1281.0 10.0 1l9.0 93 P 1282.0 9.0 113.0 91 N 1284.0 10.0 116.0 91 P 1285.0 11.0 119.5 93 P 1277.0 11.5 1l2.5 92 N 1278.0 10.5 115.0 90 P 1283.0 12.0 113.5 90 I 1284.0 11.0 115.0 90 P 1286.0 8.5 117.5 90 L 1282.0 11.0 118.5 91 L ! 1283.0 9.5 119.0 91 L 1237.0 14.5 116.0 9t P 1238.0 13.0 117.0 91 B 10.5 115.0 ~2 N 10.5 115.5 90 P 9.5 119.0 92 L 11.0 116.0 91 P 8.0 114.0 91 N 10.0 111.5 90 K 11.0 112.5 91 K 9.5 113.0 90 N 10.5 118.5 91 L 13.0 116.5 91 P t5.5 107,5 93 Q 19.5 t03.5 89 Q 16.0 115.0 90 P 15.5 115.5 90 B 1237.0 1238.0 1286.0 1287.0 1230.0 1231.0 1241.0 1242.0 1240.0 1241.0 1237.0 JUNE 28, 1999 TABLE T-I 4 ?P I I I I I I I I I I I I il II II I I I I "''''mE' "S"1J".'.'..' ....n__... ".n .... . ..... ""H.__'. ...,.... :':;::':::':';:::--:- "';:";:;:::::;::: .--,.,.....---..,.....-.......-.. ',",",",':",":':':':':':':':':',':",':',";"""-"-' ""J)'])E"" "',',,', ....... .... ..... '//} , A' ',' //, ..........""...,'.-",.._--,' .... ...-. 04/05/99 04/05/99 04/05/99 04/05/99 04/05/99 04/05/99 04/06/99 04/06/99 04/14/99 04/14/99 04/14/99 04/09/99 04/09/99 04/14/99 04/14/99 04/15/99 04/17/99 04/]7/99 04/17/99 04/17/99 04/1 7/99 04/17/99 '_ 04/17 /99 04/17/99 04/1 7/99 04/17/99 04/17/99 04/19/99 04/19/99 04/19/99 04/19/99 04/19/99 04/19/99 04/19/99 04/19/99 04/19/99 04/19/99 04/19/99 04/19/99 04/20/99 04/20/99 04/20/99 04/20/99 04/20/99 ''',,,,,,sm' :,:),;,::I,Jij. ,:l/,:: ,."."..."........,' ..--.--,.-.-....----.---.... ...................... WW NO! ? .n ................ 2344 2345 2348 2349 2358 2359 2382 2383 2411 24]2 2413 2415 2416 2417 2418 2436 2479 2480 2481 2482 2485 2486 2487 2509 2510 2511 2512 2517 2518 2519 2520 2530 2531 2532 2533 2534 2537 2541 2542 2543 2564 2565 2568 2569 TABLE I Field Density Test Results ...........,..,...'.TEST"" ;ill~AitIII TR 23143-2/Lot 18 TR 23143-2/Lot 19 TR 23143-2/Lot 19 TR 23 1 43-2/Lot 19 TR 23143-2/Lot 17 TR 23143-2/Lot ] 7 TR 23143-4/Lot 9 slope TR 23,j43-4/Lot 9 slope TR 23143-2/Lot 25 TR 23143-4/Lot 26 RT No. 2411 TR 23143-2/Lot 26 TR 23 I 43-4/Lot 25 RT No. 2413 TR23143-2/Lot 25 RTNo.2417 TR 23143-4/Lot 1 TR 23143-4/Lot 29 TR 23143-4/Lot 4 TR 23 1 43-4/Lot 5 TR23143-4/Lot 6 TR23143-4/Lot 7 TR23] 43-4/Lot 8 TR 23143-4/Lot 9 TR 23143-4/Lot I] TR 23 1 43-4/Lot 12 TR 23 1 43-4/Lot 13 TR 23 I 43-4/Lot 14 TR 23143-4/Lot 15 TR23143-4/Lot 16 TR 23 t43-3/Lot 17 TR 23 I 43-3/Lot 26 TR 23 I 43-3/Lot 26 TR 23143-3/Lot 24 TR 23143-3/Lot 24 TR 23 I 43-4/Manchester Ct TR 23 1 43-3/Lot 24 RT No. 2534 TR 23]43-3/Lot 26 TR 23143-3/Lot 26 TR 23143-2/Lot 57 TR 23143-2/Lot 58 TR 23143-2/Lot 58 TR 23143-2/Lot 58 ,)teEM! ",....,.--...--.----,..--......"..".."...., "",' "..........,.........,..--..-...-,..... ...................................... ....-......................."..".."....... ',., ',,',',', "'("ft' "')"'" .............................. un /'{)}()t??t:::?\(:t?:, ::.:' )(:: 1243.0 1244.0 1242.0 1243.0 1244.0 1245.0 1283.0 1284.0 1241.0 1240.0 1234.0 1235.0 1241.0 FG FG FG FG FG FG FG FG FG FG FG FG FG FG FG 1245.0 1246.0 1249.0 1250.0 1281.0 1251.5 ]250.0 1251.0 1220.0 1221.0 1225.0 1226.0 PfiTRAGfOTfCHNICAL, INC. 'j.N.444-98 IIf%Tlllr(~~aJ1Ir~r!!!lIli 11.0 123.5 93 F 11.0 114.0 91 S 9.0 123.0 93 F 11.0 118.5 91 L 15.5 109.5 91 R 14.5 116.0 91 P 10.0 119.5 90 F , 12'.5 114.5 90 P 17.0 102.0 87 0 14.5 112.5 90 N 15.0 98.5 85 Q 10.5 122.0 93 Y 12.0 119.5 91 Y 19.0 109.5 89 K 17.5 102.5 83 K 19.5 103.5 89 J 10.5 117.5 92 P 12.0 117.5 91 P 10.5 115.5 90 B 12.5 117.0 91 B 9.0 119.5 90 F 10.0 119.0 90 F 13.0 16.5 90 L t1.0 121.0 91 F 13.5 113.0 92 K 9.5 118.5 91 H 10.5 120.5 91 F 9.0 118.0 90 H 8.5 118.0 90 H 10.5 117.5 90 H 8.5 121.5 91 G 9.5 116.0 91 P 10.0 117.0 90 L 11.0 122.5 93 F 10.5 120.5 91 F 9.5 109.5 86 P 12.5 121.5 92 F 10.5 121.5 92 F 7.5 121.5 92 F 7.5 118.0 89 F 8.5 119.0 90 F 7.5 117.5 90 L 10.0 115.5 90 P 11.0 115.5 90 P JUNE 28, 1999 }\ TABLE T-I 5 I I I If!!ffli~$I ,D8WiJ).. 04/20/99 I 04/20/99 04/20/99 04/20/99 I 04/20/99 04/20/99 04/20/99 I 04/20/99 04/21/99 04/21/99 I 04/21/99 04/21/99 04/21199 I 04/21/99 04/21/99 04/21/99 I 04/21/99 04/2 1/99 04/21/99 I 04/22/99 04/22/99 04/22/99 I 04/22/99 04/22/99 04/22/99 I 04/22/99 04/23/99 I 04/23/99 04/23/99 04/23/99 04/23/99 I 04/16/99 04/26/99 I 04/26/99 04/26/99 04/26/99 I 04/26/99 04/26/99 04/27/99 I 04/27/99 04/28/99 04/28/99 I 04/28/99 04/28/99 I TABLE I Field Density Test Results """"8"" :::=r{'\:i:;C;-,:I::{: ............."...,-,.. .,._......._._._'_._',_-N,...,...-.-.-,.-.-..,.-.." ..--..............,.. """"'N'@'" ,_,_n,_,_ .,"',",' ...,...,..... --','--' :t:;;::::::,;::::.,_,_ ':. i:;:::;::: 2570 2571 2572 2573 2580 2581 2582 2583 2587 2588 2589 2590 2602 2603 2604 2605 2606 2607 2609 2613 26]6 2617 2618 2619 2620 2621 2630 2639 2640 2648 2655 2465 2712 2713 2714 2715 2716 2717 2745 2746 2778 2779 2780 2785 i?...,.,....'?...,......')))!..,... "......TES;r.i..,...,i. ,LOCAxIoN TR 23 I 43-2/Lot 59 TR 23143-2/Lot 59 slope RT No. 2543 TR 23143-3/Lot 26 TR 23143-2/Lot 59 TR 23143- 2/Lot 59 TR 23 I 43-2/Lot 58 slope TR 23143-2/Lot 58 slope TR 23143- 2/Lot 59 TR 23 1 43-2/Lot 59 TR 23143- 2/Lot 57 TR 23 1 43-2/Lot 57 TR 23 1 43-2/Lot 57 slope TR 23 1 43-2/Lot 57 slope TR 23143-2/Lot 57 slope TR 23 I 43-2/Lot 57 slope TR 23 I 43-2/Lot 58 TR 23143-2/Lot 58 TR 23 I 43-4/Lot 15 slope TR 23143-4/Lot 13 TR 2314-4/open space 83/Lot II TR 2314-4/open space 83/Lot 11 TR 23143-3/Lot 57 slope TR 23143-3/Lot 57 slope TR 23143-3/Lot 57 slope TR 23143-3/Lot 57 slope TR 23143-3/Lot 24 TR 23143-3/Lot 26 TR 23143-3/Lot 25 TR 23143-3/Lot 18 slope TR 23143-2/Lot 22 slope RT No. 2436 TR23143-2/Lot 17 TR 23143- 2/Lot 18 TR 23143- 2/Lot 19 TR 23143-2/Lot 20 TR 23143- 2/Lot 21 TR 23143- 2/Lot 27 TR 23143-2/Lot 58 slope TR 23 I 43-2/Lot 58 slope TR 23143-3/Lot 22 slope TR 23143-2/Lot 57 slope TR 23143-3/Lot 57 slope RT No. 2778 ~i~ll;lrll;lr(~[~wllr~'lll 1227.0 12.0 116.0 90 B 1228.0 11.0 113.5 90 I 9.5 119.0 90 F 8.5 113.5 90 I 10.0 118.0 90 H 10.15 117.0 90 H 19.5 107.0 92 Q 21.0 105.5 91 Q 10.5 '116.5 90 B 11.0 114.5 90 P 10.0 119.0 90 M 12.0 115.5 90 B 11.0 1l7.0 90 Y 10.5 116.5 90 B 11.5 116.0 90 B 9.5 119.5 91 Y 9.5 119.0 91 Y 10.0 124.5 94 F 15.5 113.0 90 S 22.5 104.0 90 Q 17.5 111.0 90 J 16.0 113.0 90 N 12.0 119.0 90 F 11.5 118.5 90 F 10.5 120.0 91 F 11.0 119.5 90 F 8.5 120.0 91 7.5 117.5 90 7.5 119.0 90 11.5 120.5 91 16.0 t 12.0 93 13.5 107.0 92 9.0 120.5 91 10.0 114.5 90 9.0 120.0 91 10.0 t25.0 94 10.0 126.5 96 12.5 115.5 90 9.0 123.0 93 9.0 120.5 91 11.0 112.5 87 13.0 121.5 93 12.5 117.0 90 10.0 118.5 92 PETRA GEOTECHNICAL, INC. j. N. 444-98 1254.5 1230.0 1231.0 1229.0 1230.0 1232.0 1233.0 1227.0 1228.0 1228.0 1229.0 1229.0 1230.0 1231.0 1232.0 1282.0 1282.0 1278.0 1281.0 1229.0 1230.0 1227.0 1228.0 FG FG FG 1245.0 1239.0 FG FG FG FG FG FG 1237.0 1238.0 1246.0 1238.0 1239.0 L F H R Q F P F F F p F F B Z P B JUNE 28, 1999 TABLE T-I 6 ,,;V I I I I I I I I I I I I I I I I I I I TABLE I Field Density Test Results """"8";" :::\)};:I:,:r.;-: :.: - ::,:1:' ,:::t/ ..,-."..............-.-.-. """D""'A""'*E""'{ }:::J}, :./.: ,\1\- _ .:?t 04/28/99 04/28/99 04/30/99 05/06/99 05/06/99 05/07/99 05/07/99 05/1 t/99 05/1 t/99 05/18/99 05/18/99 05/18/99 ',"', iT, E, ST,,,, ',,',',",........,' .... ............ ..............,..-..,' ,.......--...,....,' ".'N'..O...'.." ......., "',' }{{:>" :, :,: ,~/: ............-.-,... 2792 2793 2823 2900 2901 2917 2918 2950 2951' 3013 3014 3015 ",imEsm", :.,-::::;-;.;.,-:.:-,.,.,.::,-,;::..:.,.,-.:,.:.,:,.:.,.,-:.;.,.:.;.,.:.;-,.,.,.:.:-;-,.;.;.:.:.;.:.;-:.;.;.,.:.:-,.:.:.;. l)[;QG4!wjQ~ TR 23143-3/Lot 22 TR 23t43-3/Lot 22 TR 23143-3/Lot 22 TR 23 1 43-2/Lot 58 slope TR 23 t43-2/Lot 58 slope TR 23143-2/Lot 59 slope TR 23 I 43-2/Lot 59 slope TR 23 143-2/Lot 57 slope TR 23 I 43-2/Lot 58 slope TR 23 1 43-2/Lot 59 TR 23143-2/Lot 58 TR 23 143-2/Lot 57 ~BJ)IIIDJ~110~f(~~~lilr~;I)_I;: 1248.0 9.0 115.5 90 P 1249.0 8.0 120.0 91 F 1250.0 9.5 1 I 1.0 90 K 1254.0 14.0 118.0 92 P 1250.0 13.0 113.5 92 K 1246.0 11.5 115.0 90 P 1247.0 10.0 113.0 90 N '1254.0 9.0 114.0 90 I 1255.0 9.0 116.0 91 P FG 10.0 125.5 95 F FG 8.0 110.0 90 K FG 9.5 116.0 91 D PE'TRA GEOTECHNICAL, INC. j. N. 444-98 JUNE 28, 1999 '91; TABLE T-I 7 I I I I I I REFERENCES Pacilic Soils Engineering, Inc., 1992, Geotechnical Grading Plan Review, Tract 23143-1. Crown Hills Development. City of Temecula. California, W.O. 400406, dated June 22.1992. 1995. Geotechnical Study and Grading Plan Review. Tract 23143-2, City of Temecula. California, W.O. 400406A, dated February 7.1995. 1996a, Geotechnical Study and Grading Plan Review, Tract 23143-4. City of Temecula. Califqrnia. W.O. 400406A, dated September 16, 1996. I I I I , 1996b, Geotechnical Study and Grading Plan Review, Tract 23143-3, Crown Hill. City of Temecula, California. W.O. 400406A, dated September 25, 1996. Petra Geotechnical. Inc., 1998. Geotechnical Investigation, Tentative Tracts 23143-2, -3, and -4, Crowne Hill. City of Temecula, Riverside County, California, J.N. 444-98, dated September 23,1998. , 1999, Interim Geotechnical Report of Rough Grading, Model Lots, Lots 3 through 6 of Tract 23143-2, and Lots 1 through 8 of Tract 23143-3, Crowne Hill, City of Temecula, Riverside County, California, J.N. 444-98. dated May 3, 1999. ' I I I I I I I I I JUNE 28, 1999 PETRA GEOTECHNICAL, INC. J.N- 444-98 .1A I I I I I I, I I I I I I II , I I I I I I I APPENDIX A LABORA TORY TEST CRITERIA LABORATORY TEST DATA PETRA GEOTECHNICAL, INC JUNE 28, 1999 J.N. 444-98 1f I I APPENDIX A I LABORA TORY TEST CRITERIA I Laboratorv lVlaximum Drv Densitv I Maximum dry density and optimum moisture content were detcnnined for selected sample of soil in accordance with AS1M Test Method D1557-91. Pertinent test values are given on Plates A-I and A-2. I Exoansion Potential ' I Expansion index tests were performed on selected samples of soil accordance with 1997 Uniform Building Code (UBC) Standard Test No. 18-2. Expansion potential classifications were determined from 1997 UBC Table l8-I-B on the basis of the expansion index values. Test results and expansion potentials are presented on Plates A-2 and A-3. I Soluble-Sulfate Analvsis I Chemical analyses were performed on selecled samples of soil to determine soluble sulfate contents. These tests were performed in accordance with California Test Method No. 417. Test results are included on Plate A-3. I Atterber~ Limits I Atterberg limit tests (Liquid Limit and Plasticity Index) were performed on selected samples to verify visual classifications. These tests were performed in accordance with AS1M Test Method D4318-84. Test results are presented on Plate A-4. I I I I I I I PETRA GEOTECHNICAL, INC. 1. N. 444-98 JUNE 28, 1999 I ~ I I I I I I I I I I I I I I I I I I I LABORATORY MAXIMUM DRY DENSITY' Boring Optimnm Maximum Number Soil Type Moisture Dry Density (%) (pcf) A Brown siltv SAND (SM) 9.5 131.5 B Lt. brown coarse siltv SAND (SM) 10.0 129.0 C Lt. brown silty SAND (SM) 9.5 130.5 D Medium-brown clayey SAND (SC) 8.5 133.0 E Tan siltv fine SAND w/ clav (SM) 10.0 129.5 F Dk. Brown silty SAND w/clav (SM) 9.0 132.0 G Orange-brown silty SAND w/clay 8.5 133.0 (SM) H Orange-brown silty SAND w/clay 9.5 130.5 (SM) I Medium-brown clayey SAND (SC) 11.0 126.5 J Tan silty-sandy CLAY (SC) 13.0 123.0 K Yellow-brown SILT (ML) 12.0 123.0 L Yellow-brown silty SAND (SM); 10.0 130.0 micaceous M Yellow-brown clayey SAND (SC) 9.5 131.5 N Yellow-brown silty SAND (SM) 11.5 125.0 0 Yellow-brown silty SAND w/clay 9.0 132.0 (SM) p Red-brown silty SAND (SM) 10.5 128.0 Q Tan SILT (ML) 16.0 116.0 R Tan sandy SILT/silty SAND (SM/ML) 12.5 120.5 S Tan coarse silty SAND (SM) 11.0 125.5 T Orange-brown silty SAND (SM) 9.5 122.0 Tl n. D. ",,' c, xm ,e>n on 110 " PLA TE A-I JUNE 28, 1999 :PETRA GEOTECHNICAL, INC. 1.N.444-98 "?1. I I I I I I I I I I I I I I I I I I I Boring Optimum Maximum Number Soil Type Moisture (%) Dry Density (pel) U Dk. Brown silty SAND (SM) 9.0 132.5 V Dk. Yellow-brown silty-clayey SAND 9.5 132.0 (SM/SC) W Tan clayey SILT (ML) t3.0 119.5 X Tan clayey SILT (ML) 17.5 It 1.5 Y Orange to dk. brown silty SAND 10.0 130.5 (SM) Z Oranoe-brown siltv SAND ISM) 9.5 1" < EXPANSION INDEX TEST DATA' Lot Number Expansion Index Expansion Potential' Tract 23143-2 17-t9 51 Medium 20-22 21 Low 57-59 34 Low 60-63 137 Very High Tract 23143-3 22-23 65 Medium 24-26 ' 21 Low 27 0 Very Low 99-102 45 Low 103-105 97 High PLA TE A-2 PETRA GEOTECHNICAL, INC. J.N.444-98 JUNE 28, 1999 "}% I I I I I I I I I I I I I I I I I I I EXPANSION INDEX TEST DATA (Continued) Lot Number Expansion Index I Expansion Potential' Tract 23143-4 1-2 11 Very Low 3 0 Very Low 4-5 4 Very Low 6-9 17 V cry Low 10 60 Medium 11-13 10 Very Low 14-15 14 Very Low 16-17 14 Very Low SOLUBLE SULFATES' I Lot I Sulfate Content (%) I Lot 18ITract 23143-2 0.0008 Lot 21/tract 23143-2 0.Q108 Lot 58ITract 23143-2 0.0144 Lot 62/tract 23143-2 0.0360 Lot 23ITract 23143-3 0.0054 Lot 27ITraet 23143-3 0.0135 Lot IlTract 23143-4 0.0096 Lot 3ITract 23143-4 0.0144 Lot 5ITract 23143-4 0.0180 Lot 10ITraet 23143-4 0.0144 Lot 14ITracl 23143-4 0.0540 PLA Tf A-3 IPETRA GEOTECHNICAL, INC. IJ.N. 444-98 JUNE 28, 1999 00.... I I I I I I I I I I I I I I I I I I I ATTERBERG LIMITS' I Lot I Plasticity Index I Lot lSrTraet 23143-2 17 Lot 61rTraet 23143-2 35 Lot 104rTraet 23143-3 24 (I) PER TEST METHOD ASTM D 1557-91 (2) PER UNIFORM BUILDING CODE STANDARD TEST 18-2 (3) PER 1997 UBC TABLE 18-I-B (4) PER CALIFORNIA TEST METHOD NO, 417 (5) PER TEST METHOD ASTM D4318-93 PLA TE A-4 'PETRA GEOTECHNICAL, INC ~.N. 444-98 JUNE 28, 1999 lip