2D DEM analyses for T-M coupling effects of extreme temperatures on surrounding rock-supporting system of a tunnel in cold region  

作　　者：张玉军 杨朝帅 王永刚 

机构地区：[1]State Key Laboratory of Geomechanics and Geotechnical Engineering (Institute of Rock and Soil Mechanics,The Chinese Academy of Sciences) [2]echnical Centre,China Railway Tunnel Group Co.,Ltd. [3]Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education (Department of Geotechnical Engineering,Tongji University)

出　　处：《Journal of Central South University》2013年第10期2905-2913,共9页中南大学学报（英文版）

基　　金：Project(2010CB732101) supported by the National Basic Research Program of China;Projects(51079145,51379201) supported by the National Natural Science Foundation of China

摘　　要：Taking the Kunlunshan Tunnel on Qinghai Tibet Railway as an engineering background, the curved wall-inverted arch lining of the tunnel was simplified into the straight wall-umbrella arch one, and the fractured rock mass with developed joints was treated as a discrete medium in the calculation. Using the UDEC code, the numerical simulations for thermo-mechanical coupling processes in the surrounding rock mass-supporting system were carried out aiming at the conditions of mean temperature, extreme highest temperature and extreme lowest temperature in one year. The distributions and changes of stresses, displacements, plastic zones, temperatures in the rock mass of near field, as well as the loading states in the model-building concrete and bolting were investigated and compared for these three computation cases. The results show that compared with the case of mean temperature, the ranges, where the temperatures of surrounding rock mass change obviously, are 6.0 m and 6.5 m, respectively, for the cases of extreme highest temperature and extreme lowest temperature; the displacements of tunnel are raised by 3.2 9.3 and 5.7 12.7 times, and the thicknesses of plastic zones reach 1.5 2.5 m and 2.0 4.5 m for case 2 and 3, respectively; the extreme temperatures of air have strong effects on the stress, deformation and failure states of supporting structure of tunnel in cold region, and the influence degree of extreme lowest temperature is the highest.Taking the Kunlunshan Tunnel on Qinghai Tibet Railway as an engineering background, the curved wall-inverted arch lining of the tunnel was simplified into the straight wall-umbrella arch one, and the fractured rock mass with developed joints was treated as a discrete medium in the calculation. Using the UDEC code, the numerical simulations for thermo-mechanical coupling processes in the surrounding rock mass-supporting system were carried out aiming at the conditions of mean temperature, extreme highest temperature and extreme lowest temperature in one year. The distributions and changes of stresses, displacements, plastic zones, temperatures in the rock mass of near field, as well as the loading states in the model-building concrete and bolting were investigated and compared for these three computation cases. The results show that compared with the case of mean temperature, the ranges, where the temperatures of surrounding rock mass change obviously, are 6.0 m and 6.5 m, respectively, for the cases of extreme highest temperature and extreme lowest temperature; the displacements of tunnel are raised by 3.2 9.3 and 5.7 12.7 times, and the thicknesses of plastic zones reach 1.5 2.5 m and 2.0 4.5 m for case 2 and 3, respectively; the extreme temperatures of air have strong effects on the stress, deformation and failure states of supporting structure of tunnel in cold region, and the influence degree of extreme lowest temperature is the highest.

关 键 词：EXTREME temperature TUNNEL in COLD region THERMO-MECHANICAL coupling DISTINCT element method numerical analysis 

分 类 号：U455.7[建筑科学—桥梁与隧道工程]