岩溶区深埋隧道围岩力学特性分析  

Mechanical Characteristics Analysis of Surrounding Rock in Deep Buried Tunnel in Karst Regions

作　　者：卞晓琳[1] 陈福全[2] 苏峰[3] 孙书伟[4] 

机构地区：[1]清华大学环境学院,北京100084 [2]福州大学土木工程学院,福建福州350002 [3]同济大学土木工程学院,上海200092 [4]中国矿业大学(北京)资源与安全工程学院,北京100083

出　　处：《中国铁道科学》2013年第1期43-49,共7页China Railway Science

基　　金：国家自然科学基金资助项目(41002090)

摘　　要：建立溶洞—隧道体系的围岩力学特性理论分析模型,采用Schwarz交替法推导既有溶洞条件下开挖深埋隧道时围岩应力和变形的解析解。以齐岳山铁路隧道为例,将围岩力学特性的解析结果与有限元数值结果进行对比,验证了模型解析解推导过程的准确性。分析结果表明:溶洞的存在使隧道开挖过程中围岩产生了偏压现象,靠近溶洞一侧的围岩产生了明显的竖向应力集中,两侧水平应力则差别不大;靠近溶洞一侧围岩产生了更大的水平位移,两侧最大值之比约为1.7;随着溶洞与隧道净距的增大,偏压现象逐渐减弱,净距大于1.5倍溶洞直径时,可以忽略溶洞对深埋隧道围岩应力的影响。A theoretical model was set up for analyzing the mechanical characteristics of the surrounding rock in karst-tunnel system, and Schwarz＇s alternative method was employed to derive the analytic solu- tions for the stress and deformation of the surrounding rocks upon excavating deep buried tunnel under the existing karst conditions. Taking Qiyueshan railway tunnel for example, the analytic results of the me- chanical characteristics of surrounding rock were compared with finite element numerical results, which validated the correctness of the process for deriving the analytic solutions of the model. Analysis results show that karst cave results in bias pressure phenomenon to the surrounding rock during tunnel excavation process. There is obvious vertical stress concentration at the surrounding rock near karst cave, and there is little difference between the horizontal stresses of two sides. Greater horizontal displacement occurs to the surrounding rock near karst cave. The ratio of the maximum values between two sides of tunnel is about 1.7. With the increasing of the clear distance between tunnel and karst cave, the bias pressure of sur- rounding rock weakens gradually. The effect of karst cave on the surrounding rock in deep buried tunnel can be neglected when the clear distance between tunnel and karst cave is greater than 1.5 times of cave di- ameter.

关 键 词：隧道 岩溶地区 溶洞 SCHWARZ交替法 围岩应力 

分 类 号：U451.2[建筑科学—桥梁与隧道工程] P642.25[交通运输工程—道路与铁道工程]