Inspection and rehabilitation of the Daly-Judge Tunnel, Park City, Utah

摘要

The Park City mining district has produced about 5 billion in dollars polymetallic ores. Mining in the claims owned by the Daly-Judge Mining Co. began in 1881. In 1885, the Anchor shaft was begun, but heavy water flow halted work in 1887, and a drainage tunnel was started. Its original length was 2,011 m, and it was timbered with a standard, four-piece tunnel set, with the sills hitched into the ribs. The tunnel was eventually extended to 3,292 m, and became known as the Daly-Judge Tunnel. It passes near two shafts and through two major faults. The tunnel requires maintenance because it provides part of the potable water supply for several users in the area. The water quality is excellent, but roof falls can increase particulate content so that the water must be diverted. In August 2001, it was decided to rehabilitate the tunnel so that its contribution to the area's water supply during the 2002 Olympic Winter Games would be uninterrupted.