2. Perform Standard Penetration Tests (SPTs) to estimate relative density and cohesive
consistency of the in-situ soil units;
3. Estimate the engineering properties of the subsurface strata for geotechnical engineering
analyses; and
4. Determine the depths to competent soil and/or auger refusal, and the depth to the
groundwater table.
The test boring was drilled as near as possible to the surveyed location of the proposed traffic
signal mast arm structure. Boring B-1 was drilled to a depth of approximately 8.5 feet below
ground surface and terminated due to auger refusal. Test probe P-1 was drilled to a depth of
approximately 8.5 feet below ground surface and terminated due to auger refusal. Auger refusals
at both boring locations are presumed to be on the top of the bedrock surface; however, bedrock
core sampling is required to verify the elevation of bedrock with certainty.
Split-spoon soil samples were obtained continuously from the ground surface through a fill layer
at the location of test boring B-1 using a 1-3/8 inch inside-diameter split-spoon sampler during
the Standard Penetration Tests (SPTs). The SPTs were performed with a 140-pound hammer
dropping 30 inches, in general accordance with ASTM D1586. The number of hammer blows
required to drive the sampler between the 6- and 18-inch depth intervals (the “N” value) for each
sample was used to assess the relative density and elastic properties of the soil units. No split-
spoon soil samples were collected during the advancement of test probe P-1, which was drilled
approximately 6 feet to the north of test boring B-1.
A Miller Engineering & Testing, Inc. geologist monitored the advancement of subsurface
explorations, classified soil samples, measured groundwater levels, and observed the
performance of the Standard Penetration Tests. The test boring location was located/surveyed by
others.
SUBSURFACE CONDITIONS ENCOUNTERED
Observations and characterization of split-spoon soil samples collected at the location of test
boring B-1 indicate that subsurface conditions consist of the following generalized profile from
the ground surface downward:
1. Topsoil Layer
2. Fill Layer
3. Original Topsoil Layer
4. Subsoil Layer
5. Sand and Gravel Deposits
6. Auger Refusal
Detailed descriptions of the subsurface conditions are provided on the Test Boring Logs
presented as Attachment B. General descriptions of the units encountered are as follows:
