拉西瓦水电站Ⅱ#变形体爆破动力稳定性研究

Research on Dynamic Stability of Lxw Ⅱ# Block Subjected to Blasting Load

基于大型分析系统FINAL,采用特有的动态接触界面单元模拟潜在滑动面,对拉西瓦水电站左岸坝肩Ⅱ#变形体在爆破振动荷载作用下的动力稳定性进行了有限元时程分析,提出了适用于拉西瓦工程边坡的爆破安全判据。数值仿真分析结果表明:采用动态接触界面单元充分考虑了岩体中贯通性结构面对爆振波传播特性的影响,以及对边坡动力稳定性的影响;爆破作用对拉西瓦坝肩这样的较大的坡体的整体安全性影响不大,但对局部失稳破坏的作用较明显,当单响爆破药量达300kg时,坡体的整体最小动态安全系数为1.32,相对于静态安全系数降低了不到10%。本文的分析结果对工程中岩质高边坡爆破施工和动力稳定性分析有较好的借鉴或指导作用。

With a special contact and impact interface element to simulate the slip surface, dynamic stability analysis for an instability block located in left abutment slope of LXW is carried out by means of software FINAL. The new method proposed in this paper takes full account of continuity structures＇ influence on the dynamic stability of high rock slope and wave propagation in jointed rock mass. The criterion of blasting failure is also put forward. The results obtained by time history analysis are of great significance to blasting excavation and to optimize the design of rock slope subjected to blasting load.