Measurement and analysis on the thickness of power tunnels' loosened zone for Bakun Hydropower Station

摘要

In order to estimate the excavating quality, confirm the shoring scheme, analyze the rock stability, the sonic wave test method is used on the loosened zone. The thickness of loosened zone and the value of dynamic deformation modulus are provided. The rule of loosened zone is analyzed. The blasting impact on loosened zone is strong. The result that the rock mechanics characteristics are obviously weakened is controlled by the type of rock mass.