Subsurface Materials
Commercial Soil Test Borings (C-01 through C-05) were performed through the existing pavement of the commercial area and will be discussed in Section 3 – Commercial Development of this report. Residential Soil Test Borings (R-01 through R-11) were performed in the undeveloped parcels and are discussed below. The subsurface materials were classified by laboratory testing in accordance with the Unified Soils Classification System (USCS).
Referring to Figure 2, Test Boring Location Plan, clay, claystone and shale bedrock were encountered in Test Borings R-05, R-06, R-08, R-10 and R-11 in the southwest portion of the site. Silty sand was encountered in the other residential borings throughout the 20-foot depth tested across the north and eastern portions of the site.
Soil Test Borings: R-01, R-02, R-03, R-04, R-07, R-09
0 to 20-feet: Tan to brown, loose to medium dense, moist (wet below the water table), Silty Sand. This soil classifies primarily throughout its depth as SW-SM, well-graded silty sand with gravel.
Soil Test Borings: R-05, R-06, R-08, R-10, R-11
0 to 5-14-feet: Tan to brown, loose to medium dense, moist (wet below the water table), Silty Sand. This soil classifies primarily throughout its depth as SW-SM, well-graded silty sand with gravel.
5-14 to 20-feet: Gray, hard to very hard, moist claystone and shale bedrock. These soils classify primarily as CL, lean clay, and CH, fat sandy clay.
Additional descriptions and the interpreted distribution (approximate depths) of the subsurface materials are presented on the Test Boring Logs. The descriptions shown on the logs are based upon the engineer’s classification of the samples at the depths indicated. Stratification lines shown on the logs represent the approximate boundaries between material types and the actual transitions may be gradual and vary with location.
Groundwater
Groundwater was encountered intermittently across the site. The well-graded sand appears to be well-draining with groundwater encountered at 13 to19-feet depth. In those borings where claystone and shale bedrock were encountered, groundwater was perched as high as 6-feet below ground surface elevation. Depending upon final site grading and finished floor elevations, groundwater may influence the feasibility of certain structures, particularly basement construction. Fluctuations in groundwater and subsurface moisture conditions may occur due to seasonal variations in rainfall and other factors not readily apparent at this time.