洞室群围岩应力集中效应放大现象的数值模拟  

Numerical Simulation of Magnification Phenomenon of Stress Concentration Effect During Tunnels' Excavation

作　　者：陈永前[1] 邢博瑞[1,2] 李凤[3] 

机构地区：[1]中国地震局地壳应力研究所地壳动力学实验室,北京100085 [2]中国地质大学,北京100083 [3]河北省地震局,石家庄050021

出　　处：《三峡大学学报（自然科学版）》2014年第4期50-56,共7页Journal of China Three Gorges University：Natural Sciences

基　　金：国家自然科学基金青年基金项目(40704018);中央级科研院所基本科研业务专项资助项目(ZDJ2012-20);国家自然科学重点项目(51038009)

摘　　要：为了研究洞室群开挖过程中围岩应力集中效应放大现象的变化规律,本文根据不同的截面形状、不同的水平距离、不同的空间位置,利用3D-Sigma软件设计了4组洞室群模型,第1组包含5个模型,其他组均包含3个模型,以此来模拟后期开挖洞室的不同布置方案对前期洞室的影响规律.通过在拱顶、拱底和左右拱脚等部位设立应力监测点,得到了后期洞室群开挖过程中前期洞室围岩中代表性部位应力值的变化.最后从最大主应力和最小主应力两个方面,详细分析了开挖过程中随着洞室间距以及后期开挖洞室位置的变化洞室群围岩应力集中情况,得出了洞室群开挖过程中围岩应力集中效应的放大规律.该规律对深部洞室群稳定性控制具有指导意义.In order tostudy the variation law of theamplification phenomenon of stress concentration effect in the surrounding rock mass of tunnels,four different numerical models are constructed with 3D-Sigma soft-ware considering section shapes,spacing distances,spatial positions.The first group includes five numerical models and the other three groups include three numerical models.These numerical models are used to simu-late the impacts of the subsequently-excavated tunnel on the previously-excavated tunnel.During the numeri-cal modeling process,the stress concentration monitoring points are set respectively at the top and bottom of arch and the right and left arch springs of the section of the previously-excavated tunnel.The variation law of stresses at these monitoring spots can be got by analyzing the maximum and minimum principal stress magni-tudes during the subsequent steps.Four groups of models prove that there exist marked amplification phe-nomenon of stress concentration effect at the typical spots,i.e.the subsequent excavation makes the stress concentration effect more severe.This finding is of great significance to the stability control of deeply-buried group tunnels or caverns.

关 键 词：洞室群 应力集中 放大现象 数值模拟 

分 类 号：U453.2[建筑科学—桥梁与隧道工程]