LIMITATIONS
Explorations
The analyses, recommendations and designs submitted in this report are based in part
upon the data obtained from subsurface explorations. The nature and extent of variations
between these explorations may not become evident until construction. If variations then
appear evident, it will be necessary to re-evaluate the recommendations of this report.
DANIEL WEBSTER HIGHWAY
GRAHAM DRIVE
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Greenman-Pedersen, Inc,
Engineers, Akiucte, Planners, Conviction Enginaars & hopectors
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PREPARED FOR,
PROJECT
‘TRAFFIC SIGNAL IMPROVEMENTS
NASHUA, NEW HAMPSHIRE
BORING LOCATION PLAN
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FINAL DESIGN CONSTRUCTION MONITORING
granular fill material would require that the excavation be sufficiently sloped to conform to
OSHA Guidelines Title 29 CFR Subpart P 1926.650. Considering the site constraints, a shoring
system may be required where an open excavation is impractical.
The following Table summarizes the required mast arm foundation sizes for spread footing and
drilled pier foundation alternatives:
Recommended Foundations Types
APPROXIMATE THICKNESSES OF STRATIGRAPHIC UNITS PENETRATED
AND DEPTH TO AUGER REFUSAL AT B-1
STRATIGRAPHIC UNIT B-1 P-1
Topsoil Layer 0.2 ft. -
Fill Layer 2.8 ft. -
Old Topsoil Layer 0.25 ft. -
Subsoil Layer 0.75 ft. -
Sand and Gravel Layer 4.5 ft. -
Auger Refusal 8.5 8.5
Note:
1. Samples were not collected during the advancement of test probe P-1. This probe was
advanced to confirm the depth to auger refusal encountered at B-1.
Groundwater Conditions
Topsoil Layer
A 2 inch thick topsoil layer was observed at test boring B-1. The topsoil layer consists of dark
brown to grey, dry, loose, silt and very fine sand with abundant roots. A trace amount of fine
gravel was noted.
Fill Layer
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.
e Google Earth recent aerial photographs depicting existing conditions at the site and
surrounds;
e Surficial Geology of the Nashua South Quadrangle, New Hampshire;
e USGS 7.5 Minute Series Nashua South Quadrangle, New Hampshire; and
e Geologic Map of the Nashua South Quadrangle, Hillsborough County, New Hampshire
and Middlesex County, Massachusetts.
Existing Conditions
