岩体结构对大型地下挖掘稳定性的控制作用

岩体结构是地质年代形成和变动的结果.它反映了裂隙的密度并控制大型地下挖掘工程顶部岩体的力学性能.文章以溪洛渡水电站地下工程为例,根据断裂分布情况的研究对岩体进行分类.采用结构力学方法和UNWEDGE程序讨论了单个裂隙,成组裂隙和岩石碎块情况下顶部的稳定性来得到临界稳定厚度和可能失稳岩决的特点,可以为挖掘和支撑工作提供有益的指导.

Control Effect of Rock Mass Structure on Stability of Large Underground Excavation

Rock mass structure is the result of formation and reworking during the geological period. It reflects the density of discontinuities and controls the mechanical behavior of rock mass in the hat of a large underground excavation. Taking the underground excavation of Xiluodu Hydroelectric Power Station as an example, the rock mass structure is classified based on research on distribution of fractures. Adopting the structural mechanics method and UNWEDGE program, the hat stability under single fracture, groups of fractures and fragmentized rock mass is discussed in this paper to obtain the critical stable thickness and the feature of potentially instable blocks, which can be a beneficial guidance to excavation and timbering.