摘要
长大公路隧道通风竖井通常建设在地应力作用的岩体区域,地应力状态是影响竖井工程稳定性最重要的因素之一。为探明高地应力状态对深大竖井围岩的应力演化和变形规律的影响,依托米仓山特长隧道通风竖井工程,采用数值模拟对不同应力系数的竖井施工过程进行分析,研究了不同应力条件下大断面竖井沿不同深度的围岩应力特征及径向位移规律。研究结果表明:相差较大地应力系数对围岩位移分布规律产生较大影响;围岩径向位移与围岩级别及竖井深度呈正相关性,围岩级别变差比竖井深度增大对围岩径向位移的影响更为明显;但当竖井深度超过200 m时,随地应力系数增大竖井径向位移速率急剧增大;不同围岩级别条件下随竖井深度和应力系数的增大,径向应力和切向应力都呈增大趋势,但增大趋势较平缓;研究成果可为类似竖井工程的科研、设计和施工提供参考。
The ventilation shaft of extra-long highway tunnel is usually built in the area of rock mass under the effects of in-situ stress,and the in-situ stress state is one of the most important factors affecting the stability of shaft engineering. In order to explore the influence of in-situ stress state on the stress evolution and the deformation law of surrounding rocks of the deep and large shaft,based on a ventilation shaft project of Micangshan extra-long tunnel,the numerical simulation of the process of shaft construction with different stress coefficients is carried out to study the stress characteristics and radial displacement law of surrounding rocks with different depths under various stress conditions. Study results show that the major difference among stress coefficients has a greater impacts on the displacement distribution law. The radial displacement is positively correlated with the surrounding rock classification and the shaft depth,and the influence of surrounding rock classification on radial displacement of surrounding rock is more remarkable than that of increased shaft depth. However,when the depth of shaft exceeds 200 m,the rate of radial displacement of shaft is sharply soaring up with increasing of in-situ stress coefficient. Under different classification of surrounding rocks,the radial stress and the tangential stress are both on the rise with increasing of shaft depth and stress coefficient,but the increasing trend is gentle. The study can provide a reference for the research,design and construction of similar shaft projects in future.
作者
冷希乔
严金秀
韩瑀萱
Leng Xiqiao;Yan Jinxiu;Han Yuxuan(Sichan Vocational and Technical College of Communications,Chengdu 611130,P.R.China;China Railway Southwest Research Institute Co.,Ltd.,Chengdu 611731,P.R.China;China Railway Science Research Institute Co.,Ltd.,Chengdu 610032,P.R.China;Sichuan Bashan Expressway Co.,Ltd.,Chengdu 610041,P.R.China)
出处
《地下空间与工程学报》
CSCD
北大核心
2020年第5期1451-1458,1483,共9页
Chinese Journal of Underground Space and Engineering
基金
四川省交通科技项目(2011D-04-1)。
关键词
竖井
地应力
应力系数
应力特征
径向位移
shaft
in-situ stress
stress coefficient
stress characteristics
radial displacement
