开挖走向对某节理隧洞块体稳定性的影响

Influence of Excavation Trend to the Stability of Cave Blocks

节理裂隙岩体地下洞室开挖工程中隧道走向的选取至关重要,是影响开挖后隧洞围岩整体稳定性的重要可控因素。为优化开挖方案,需要对开挖后隧洞围岩稳定性进行分析和预测。本文基于关键块体理论,结合工程实例,选取不同隧洞走向对某隧洞随机块体稳定性进行了模拟分析。结果表明:与隧洞轴线走向相近的缓倾角节理为危险结构面,更易形成不稳定块体。在轴线走向与工程区不连续结构面交角由小变大的过程中,随机块体数量增多,体积变小,安全系数普遍有增大趋势。

Trend selection is critical to the underground tunnel excavation project in the jointed rock mass, and it is the importantcontrollable factors to the overall stability of surrounding cavern after excavation. In order to optimize the excavation scheme, we need toanalyze and predict tunnel surrounding rock stability after the excavation. Based on the key block theory, this study combined with a realengineering project, selected multiple tunnel trend to simulate and analyze the stability of random blocks. The results show that low angle jointsets with a similar trend with underground cavern axis are dangerous structural surface and easy to form unstable key blocks. During theprocess of the angle between excavation trend and discontinuous structural surface in project area becoming from small to large, the number ofrandom blocks increases, the volume becomes smaller and the safety factor has the trend of increasing in general.