水电站地下厂房安装间的块体稳定性分析

Block Stability Analysis of Erection Room of Underground Powerhouse

基于地质勘查资料,首先运用赤平极射投影方法定性评价了某水电站地下厂房安装间的稳定性,表明其边墙、端墙和顶拱存在局部失稳问题;然后利用块体理论,将块体分为定位块体、半定位块体与随机块体,仅考虑由三组结构面与开挖面形成的楔形块体,对安装间中存在的三大类块体进行了定量统计,统计结果表明安装间顶拱部位可能发育很大的定位块体、半定位块体和随机块体,且均从顶拱直接坠落,所有安全系数小于2的半定位块体和随机块体均分布在顶拱。

Based on the geological survey information of erection room of an underground powerhouse, the block stability analysis is made on the erection room with stereographic projection mapping method. It is shown that there are local instability problems at the side wall, head wall and crown of the room. According to the block theory, the blocks are divided into positioning, semi-positioning, and random ones. Only considering the wedges composed of three joint faces and excavation face, a quantitative statistics analysis is made on all three kinds of blocks for the erec- tion room. It is concluded from the statistics analysis that the three kinds of blocks are developed at the crown of erection room and they would fall directly from the crown, and the safety factors of all semi-positioning and random blocks of the crown are less than 2.