摘要
针对目前洞库开挖全过程的围岩应力-应变的长期监控测量以及围岩应力-应变解析解的研究的不足,该文依托某巨跨洞库工程,通过布设监测断面对洞库开挖的整个过程中围岩的应力场及应变场的变化进行了长期监测。采用数值模拟方法对3种开挖方式开挖过程中围岩应力场的变化进行了分析。同时,采用复变函数理论结合柯西积分方法,给出了巨跨洞库围岩应力及位移计算方法,得到了巨跨洞库围岩及支护结构的应力解析解。研究表明:巨跨超扁平隧道起拱线截面易产生较大应力集中现象;在开挖过程中洞周岩层劣化会引起应力空间转移;双岩柱开挖法能够充分发挥锚索等支护结构的承载力以及围岩自承载能力。
In view of the insufficiency in the long-term monitoring and measurement of surrounding rock stress and strain during the whole process of cavern excavation and in the study of analytical solution of surrounding rock stress and strain,the changes of stress field and strain field of surrounding rock during the whole process of cavern excavation were monitored for a long term by arranging monitoring sections,with a very large span cavern taken as an example.Based on numerical simulations,three excavation methods were used to analyze the variation of surrounding rock stress field during excavation of cavern.Furthermore,the complex function theory in combination with Cauchy integral method was used to derive a method of calculating the stress and displacement of surrounding rock of the very large span cavern,and analytical solutions for stresses of surrounding rock and supporting structure of the very large span cavern were obtained.The research results show that the springline section of the very large span and very flat tunnel is prone to large stress concentration;in the process of excavation,the deterioration of rock strata around the tunnel may cause the spatial transfer of stress;double rock pillar excavation can give full play to the bearing capacity of anchor cable and that of surrounding rock itself.
作者
洪开荣
刘永胜
李鹏飞
张程远
潘岳
杨朝帅
Hong Kairong;Liu Yongsheng;Li Pengfei;Zhang Chengyuan;Pan Yue;Yang Chaoshuai(China Railway Tunnel Group,Guangzhou 511458,China;Guangdong Provincial Key Laboratory of Intelligent Monitoring and Maintenance of Tunnel Structure,Guangzhou 511458,China;University of Science and Technology Beijing,Beijing 100083,China;Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430064,China)
出处
《土木工程学报》
EI
CSCD
北大核心
2022年第9期118-128,共11页
China Civil Engineering Journal
关键词
巨跨洞库
开挖
应力场
扰动
very large span caverns
excavation
stress field
disturbance
