Atch 9 bridge auger report.pdf

This document is a USDA Forest Service computation sheet containing geotechnical boring logs and soil descriptions for the Sand Pond Bridge (East) site, dated September 12, 2025, and prepared by J. Berry/Jzeni.

The document details subsurface conditions at three borehole locations (Borehole 2 Downstream Right, Borehole 1 Downstream Left, and Borehole 3 Downstream Right) with depth measurements and corresponding soil descriptions. Notable findings include varied soil compositions across depths, including organic materials and grasses at surface levels (0'-8'), iron-stained white fine sands with organics, light tan consistent sands, saturated caramel-colored fine sands with some red staining, and white fine grain fully saturated fine liquified sands at depths between 2.4' and 5.1'. The logs document sand grain sizes ranging from fine to medium, with blue coloring noted at certain depths. Several boreholes encountered difficult augering conditions and obstructions including boulders and bedrock, with one location noting a sound of large gravel when auggering and inability to recover the last 3 inches of material, assumed to be coarse gravel. The boring data includes observations about saturation levels, organics content, and groundwater conditions, providing baseline subsurface information for bridge design and construction purposes.