在地下厂房的长期使用期限内,其除了承受自身开挖引起的应力作用外,还将受到许多不可预知力的作用,地震就是其中之一。而地震动荷载下地下洞室的响应分析是一个复杂的问题。虽然地下工程的设计方法逐渐成熟,但目前仍以拟静力方法为主。本文以某水电站地下厂房洞室群为例,利用FLAC3D对其进行了动力分析,详细说明了计算步骤。计算结果表明,地震动作用增加了洞室临空面变形,且计算结果大于拟静力方法计算的结果,在进行工程设计时,应慎重选择。本文的计算成果可以为类似的工程计算提供参考。
Beside the excavation-caused stress forces,an underground workshop in its lifetime usually suffers from various unpredicted forces such as earthquake forces.Analysis on the dynamical responses of underground caverns to earthquakes is a complicated issue of engineering design and pseudo-static method remains dominant even through the current design method of underground engineering is quite mature.This work uses a case study of a hydropower station,simulates the dynamical responses of its underground cavern by FLAC3D,and explains the calculation steps in details.The results show that earthquake forces increase the displacements of cavern,i.e.larger values than the ones by pseudo-static method,which indicates that extreme caution should be taken in the design.