开挖方式对地下厂房洞室群围岩力学特性的影响

为了解大型地下厂房洞周围岩的力学性态，以金沙江某地下厂房洞室群为工程背景，基于卸荷岩体力学理论，采用三维有限差分法，研究不同开挖方式对洞室群洞周围岩卸荷力学特性的影响。计算结果表明：不同开挖方案对洞周围岩卸荷影响程度均较小；洞室群开挖后，主厂房、尾调室顶拱围岩卸荷程度远小于边墙；受相邻洞室开挖的影响，主变洞顶拱卸荷程度较大，但深度较浅；由于尾调室顶拱围岩力学参数优于主厂房顶拱，其卸荷程度略小于主厂房顶拱；尾调室高边墙卸荷程度大于主厂房边墙。该研究成果对工程设计与施工具有指导意义。

Influence of different excavation modes on mechanical properties of surrounding rock in underground powerhouse caverns group

The aim of thesis is to obtain the unloading mechanical properties of surrounding rock in the large underground powerhouse caverns group excavated by different ways.With the case of the caverns of a hydropower station on Jinsha River,the influence of unloading mechanical properties of surrounding rock to caverns by different excavation ways is researched based on the theory of unloading rock mass mechanics and the 3D finite difference method.The results show that the unloading extent of surrounding rock by different excavations is relatively little;the unloading extent of surrounding rock in the main powerhouse and on the top of tailwater room is far less than that of the side wall after the excavation of caverns;the unloading change of main-transformed cavern is in the top arch but with a shallow depth due to the excavating influence of adjacent cavern room;because the mechanical parameters of surrounding rock on the top of tailwater room is better than the top arch of the main powerhouse,the unloading extent is slightly less than that of the main powerhouse;the unloading extent of high sidewall in the tailwater room is greater than that of the powerhouse.