Abstract:

The angle between the longitudinal axis of the underground power plant of Pengshui Hydropower Station on Wujiang River in Chongqing and the strike of the thinstratified steepinclined limestone containing weak shale is 0° and the surrounding rock mass has poor selfsupport capability and quick unloading deformation, which is extremely unfavorable to the safety of the anchor beam structure installed on the high side walls. The influence of the rock mass unloading on the rock anchor beam structure installed on the high side walls is analyzed on basis of the mechanical behavior of the rock mass during loading and unloading. In order to control the safety of the rock anchor beam of the power plant, the typical sections of the power plant are selected as calculation profile and simulation is made on the excavation and reinforcement of the power plant and on the construction and operation of the rock anchor beam by finite difference method. The deformation and stress of the surrounding rock mass and support structure of the power plant and the deformation and stress of the rock anchor crane beam are analyzed in detail. The calculation and analysis provides guidance to the construction. The monitoring data indicates that the beam structure is safe and reliable.

Key words: thinstratified steep inclined soft rock, high side wall parallel to rock mass strike, rock mass stress, rock mass deformation, rock anchor crane beam, safety of beam structure, underground power plant of Pengshui Hydropower Station