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<br />Subsidence Investigation
<br />Mathewl Aley Rental Property
<br />Claim No. 223968
<br />
<br />BCI Project No. 03-15564
<br />November 2007
<br />Page 6
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<br />2.8 Standard Penetration Test Borings
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<br />Three standard penetration test (SPT) borings, SPT-I to SPT-3, were completed at the Mathew/Aley
<br />Rental Property on October 17,2007, at the locations shown on Figure 2. Boring SPT-I was located along the
<br />west side of the house, within GPR anomaly Feature I and adjacent to the ground collapse feature. The boring
<br />was completed to a depth of 65 feet below grade. Boring SPT-2 was located near the northwest comer of the
<br />garage and was completed to a depth of 60 feet below grade. Boring SPT-3 was located along the south wall of
<br />the house and was completed to a depth of 75 feet below grade.
<br />
<br />Drilling services were provided by Independent Drilling, Inc., utilizing a track-mounted, limited access
<br />drill rig and mud rotary drilling method. Soil samples were collected from each borehole in general accordance
<br />with ASTM Standard DI586 using a lA-inch LD. split-spoon sampler driven with a 140-pound slide hammer
<br />falling a distance of 30 inches. Soil samples from each boring were placed in sealed jars and returned to BCl's
<br />office for further classification and laboratory testing. Upon completion, each borehole was plugged with cement
<br />grout. Boring logs are included in Appendix C.
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<br />3.0 SUBSURFACE CONDITIONS
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<br />3.1 Geological Conditions
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<br />The subsurface geology at the Mathew/ Aley property is illustrated in the soil boring profiles shown in
<br />Figure 5. The profiles were developed using subsurface data from the SPT borings. Based on these data, five
<br />subsurface units, or strata, were identified at the site. These units are described below.
<br />
<br />Stratum I
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<br />Stratum 2
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<br />Stratum 3
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<br />Stratum 4
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<br />Stratum 5
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<br />SAND, yellowish brown, grayish orange and yellowish gray, fine-grained quartz, local
<br />consolidated nodules USCS Classification = SP
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<br />SAND and Variably CLAYEY SAND, yellowish brown, pale orange, yellowish gray, white
<br />and yellowish orange, fine-grained quartz with local clay
<br />USCS Classification = SP, SP-SC, SC
<br />
<br />CLAYEY SAND and SANDY CLAY, white, yellowish gray, yellowish orange, yellowish
<br />brown, olive gray and greenish gray, mottled, variably sandy and clayey, local sand lenses
<br />USCS Classification = SC, CH
<br />
<br />SANDY CLAY and CLAYEY SAND, greenish gray, yellowish orange, yellowish gray,
<br />yellowish brown, white, mottled, variably sandy and clayey, local interbedded sand,
<br />limestone fragments and sand lenses USCS Classification = SC, CH with SP
<br />
<br />LIMESTONE, white, pale orange, gray, yellowish gray, yellowish orange, greenish gray and
<br />bluish gray, local lenses oflime silt, minor clay in fractures, locally cherty, variably indurated
<br />
<br />The surficial soil unit at the site (Stratum I) consists of a variably thick layer of fme-grained quartz sand
<br />extending from the ground surface to depths of 12 feet below grade in borings SPT-I and SPT-2 and 8 feet below
<br />grade in boring SPT-3. Recorded SPT blow counts in Stratum I ranged from 2 to 6 blows per foot, indicating a
<br />very loose to loose relative density for the soil unit.
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