断面形式对水电站节理隧洞稳定性的影响

Influence of Cross Section Forms to the Stability of Blocks of Joint Hydropower Cavern

断面形式的选择对水电站节理岩体地下洞室围岩的稳定性十分重要,也是影响其长期安全稳定运行的重要可控因素。为选择合理的断面形式、优化施工方案,在关键块体理论的基础上,利用UNWEDGE计算程序,选取4种不同断面形式隧洞进行了模拟分析。结果表明:断面形式对关键块体的体积、安全系数及所需的支护力都有重要影响。当断面从圆形向正方形过渡的过程中,关键块体的数量基本不变,但体积逐渐变大,安全系数普遍减小,需要支护的块体数量增多,围岩稳定性降低。

The choice of a section form is crucial to the stability of rock mass of underground caverns in a hydropower station and also is an important controllable factor to its long-term security and stability. In order to optimize the construction scheme and choose a reasonable crosssection form,based on the key block theory,using block analysis program UNWEDGE,4 kinds of different cross section tunnels were simulated and analyzed. The results show that the section form has a significant impact on the volume,safety factor and the required supporting force of the key blocks,but has little influence on its number. As the cross section changed from circular to square,the number of key blocks is basically unchanged but the volume is gradually larger,safety factors generally reduced,the number of blocks need to be supported increased and the stability of surrounding rock decreased.