WY.FLAP.SHE.26(1).Red Grade Road.Geotech Rpt FINAL.Apr 2025_Rock Ex, Cut & Fill Rockeries, Buttress, SRE.pdf

This is a Geotechnical Report documenting subsurface conditions and design recommendations for the WY FLAP SHE 26(1) Red Grade Road improvement project. The report provides engineering analysis supporting Phase 1 construction activities, including rock excavation, cut and fill operations, rockeries, buttress structures, and soil retention engineering (SRE). The geotechnical investigation characterizes soil and rock conditions along the roadway corridor to inform design parameters for roadway rehabilitation, widening, and minor realignment of Red Grade Road (County Road 26/USFS Route FSR 26), which connects Wyoming State Highway 335 to U.S. Highway 14 and provides access to Bighorn National Forest and BLM lands.

The report addresses subsurface conditions necessary for contractors to execute earthwork and stabilization requirements, including foundation design for structural elements such as rockeries and buttress installations. This technical document serves as a design deliverable prepared in April 2025 and provides the geotechnical basis for construction specifications related to excavation depths, fill material requirements, and slope stability measures required to address substandard roadway sections, geometrics, and safety deficiencies along the project corridor. The findings and recommendations contained in this report are essential for bid preparation and construction execution under the Federal Highway Administration-funded project.