Tioga Road Rehabilitation Geotechnical Borings

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The Federal Highways Administration would contract with a consultant to provide a mechanical boring machine for drilling up to 225 exploratory borings on the Tioga Road between Crane Flat and Tuolumne Campground Road (40 miles). These borings would provide geotechnical information for the design of the Tioga Road Rehabilitation Project. The design team needs to know the soil and subgrade conditions of Tioga Road. The data gathered will provide information needed to repair or stabilize the subgrade and associated drainages, as well as provide information for a successful asphalt mix.
The proposal includes 160 borings, 6 inches in diameter and up to 24 inches deep; 40 borings, 6 inches in diameter and up to 8 feet deep; and 25 borings, 8 inches in diameter and up to 30 feet deep.
Upon completion, each bored hole would be backfilled and compacted with the same subgrade material that was taken out and repaved with new asphalt concrete. Where traffic may be delayed, flaggers with radio communication would be positioned at each end of the boring machine to keep one lane of traffic open at all times (with up to 15 minute delays).