AZ BL COLO 7528(1) Burro Creek Road_FINAL GEO Report and FINAL PVMNT Report.pdf

This is a Geotechnical and Pavement Report for a federal highway project managed by the Federal Highway Administration Central Federal Lands Highway Division (FHWA-CFLHD). The project involves the rehabilitation of approximately 1.3 miles of Burro Creek Road in Wikieup, Arizona (AZ BL COLO 7528), located within the Burro Creek Recreation Area under Bureau of Land Management jurisdiction and approximately 70 miles southeast of Kingman, Arizona.

The project scope includes pulverizing the existing 26- to 28-foot-wide asphalt concrete roadway and paving a new 22-foot-wide travel way over full-depth reclamation base, implementing drainage improvements including culvert repairs and replacements, ditch reconditioning with minor rock scaling on cut slopes, embankment reconstruction to address erosion, reconditioning bridge abutment backfill to address subsidence, and erosion control for graded slopes. The geotechnical evaluation consisted of thirteen borings drilled to depths of 1 to 9 feet below ground surface on September 23, 2025, comprehensive laboratory testing of soil samples including particle size analysis, Atterberg limits, Proctor compaction, corrosion testing (pH, resistivity, soluble sulfates and chlorides), and R-Value testing. The recommended pavement structural section consists of a minimum 3.5 inches of hot mix asphalt (Type 402 or 403) over a minimum 4 inches of full depth reclamation material, with pulverization extending to at least 4 inches below existing pavement surface. The design incorporates performance grade PG70-10 asphalt binder specified for the Maricopa Association of Governments region, a 20-year design life with 87,021 estimated equivalent single axle loads, and an R-value of 36 for subgrade design. Construction considerations address excavation of bedrock and boulders using conventional heavy equipment without blasting, material sourcing from commercial suppliers near Kingman with anticipated haul times up to 2 hours, and erosion control measures including geotextile placement and flowable backfill alternatives for bridge abutment reconstruction.