Expertise on the Stability of Pilot Tunnels at Xiaolangdi Multipurpose Dam Project

摘要

Xiaolangdi Multipurpose Dam Project, which is partly supported by the World Bank, is the second large hydraulic project in China. Three Pilots in Diversion Tunnels had been excavated before Sept. 1994. The expertise on the stability of Pilot Tunnels is carried out in this paper with two methods: one is a new theory on post-failure rheological property of rock, the other is the traditional experimental method. The results from both methods show the instability of crown and sidewalls of Pilot Tunnels in some section with bad geological condition.