Sand Bar Hydroelectric Project; Tuolumne County, California, USA
Tasks Performed: Consultant responsible for conducting a detailed pre-construction evaluation for a 5.6-kilometer-long, 4.0-meter I.D. pressure tunnel. The purpose of this evaluation was to determine the feasibility of excavating the tunnel using a TBM and leaving a major portion unlined. He performed a detailed evaluation of all available geological and geotechnical information including boring logs and rock testing data. Additionally, he conducted site visits to inspect core borings and the tunnel alignment.
Duration: 1984 (2 months)
Description: Located between two existing hydroelectric projects, Sand Bar is a diversion development situated on the Middle Fork of the Stanislaus River in the rugged terrain of the western Sierra Nevada Mountain Range. The Sand Bar Project’s major features include a reinforced concrete intake structure; a 5.6 kilometer, 4.0 meter-diameter hard rock tunnel; a reinforced concrete powerhouse enclosing a single, vertical Francis turbine generator rated at 12.6 MW; and four kilometers of 115 kV, woodpole transmission line.