引水隧洞开挖释放荷载模拟方法的对比研究  

Comparative Analysis of Excavation Unloading Simulation Methods for the Diversion Tunnel

作　　者：刘仲秋[1,2] 廉照彬 章青[2] 

机构地区：[1]山东农业大学水利土木工程学院,山东泰安271018 [2]河海大学工程力学系,南京210098

出　　处：《地下空间与工程学报》2014年第2期415-422,共8页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金资助项目(11132003;51179064)

摘　　要：岩体工程开挖后的应力调整和变形与施工的具体方法和时空间效应相关,对于开挖边界等效释放荷载的模拟问题,常用的方法有应力释放法和参数弱化法。总结了应力释放法和参数弱化法两种方法的原理和优缺点,考虑在无渗流场和渗流场的两种情况,对一典型引水隧洞开挖问题中释放荷载的模拟,分别采用上述方法进行数值计算和对比分析,并采用其中的应力释放法应用于锦屏深埋引水隧洞施工开挖围岩稳定分析。分析结果表明,等效荷载释放率相同时,无渗流场情况和有渗流场情况均为应力释放法对隧洞周边应力扰动最大,应力释放法和参数间接弱化法计算结果较为相似,直接参数弱化法计算结果与二者相差较大;锦屏隧洞在实际开挖时应该采取措施控制水平方向的等效荷载释放,实际开挖工程中的同一断面不同位置的荷载释放会存在差异,将影响最终开挖损伤区的范围和损伤程度。The stress adjustment and deformation of underground rock mass after excavation are related with spe- cific process of construction methods as well as spatial and time effect, and there are two common methods to simulate equivalent excavation unloading in the boundary of excavation： stress release method and parameter weakening meth- od. After summarizing the principle of two methods and their advantage and disadvantage, comparative numerical a- nalysis of two methods were carried out using typical tunnel excavation model considering the seepage effect. Then the rock mass stability of Jinping deeply-buried diversion tunnel was analyzed using stress release method. The results showed that the maximum stress disturbed zone of surrounding rock mass appeared in stress release method with or without seepage effect, calculated results of stress release method and indirect parameter weakening method were basi- cally identical, yet the result of direct parameter weakening method was quite different from the former two methods. During the real Jinping excavation process, some measures should be taken to control the horizontal excavation unloa- ding, and there were some difference of unloading rate among the different position in the same section which would influence the scope and damage degree of final excavation damage zone.

关 键 词：释放荷载 应力释放法 参数弱化法 引水隧洞 

分 类 号：O319.56[理学—一般力学与力学基础]