PPQ S and T FPML Geotechnical Report.pdf

This document is a Geotechnical Investigation Report by Briggs Engineering & Testing for a proposed USDA building located at 1398 West Truck Road, Otis Air Base, Sandwich, MA. The investigation, completed on December 10, 2014, involved subsurface explorations through borings and test pits to assess site conditions for a one-story, slab-on-grade warehouse building. Key findings include gravelly sand fill layers, undisturbed alluvial sandy deposits, and site conditions characterized by gently sloping terrain with an asphalt parking lot.

The report provides detailed recommendations for foundation design, including using shallow spread footings on undisturbed alluvial deposits, with strip footings suggested at 4 feet depth and 2 feet width. Specific technical specifications are provided for backfill materials (Structural Fill, Granular Fill, and Crushed Stone), compaction requirements, and site preparation. The investigation determined the site is not susceptible to liquefaction and is classified as Seismic Site Class D. Recommendations cover excavation, subgrade protection, water control, and fill placement to ensure structural integrity, with careful attention to soil composition, moisture content, and compaction methods.