Anisotropic strength,deformation and failure of gneiss granite under high stress and temperature coupled true triaxial compression  

作　　者：Hongyuan Zhou Zaobao Liu Fengjiao Liu Jianfu Shao Guoliang Li 

机构地区：[1]Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines,College of Resources and Civil Engineering,Northeastern University,Shenyang,110819,China [2]Institute of Deep Engineering and Intelligent Technology,Northeastern University,Shenyang,110819,China [3]University Lille,CNRS,Centrale Lille,UMR 9013-LaMcubeeLaboratoire de Mécanique,Multiphysique,Multi-échelle,F-59000,Lille,France [4]State Key Lab on Rail&Transit Engineering Informatization,China Railway First Survey and Design Institute Group Co.Ltd,Xi’an,710043,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2024年第3期860-876,共17页岩石力学与岩土工程学报（英文版）

基　　金：This work was supported by Natural Science Foundation of China(Grant No.52278333);the Fundamental Research Funds for the Central Universities(Grant No.N2101021);The work is under the framework of the 111 Project(Grant No.B17009)and Sino-Franco Joint Research Laboratory on Multiphysics and Multiscale Rock Mechanics.

摘　　要：The anisotropic mechanical behavior of rocks under high-stress and high-temperature coupled conditions is crucial for analyzing the stability of surrounding rocks in deep underground engineering.This paper is devoted to studying the anisotropic strength,deformation and failure behavior of gneiss granite from the deep boreholes of a railway tunnel that suffers from high tectonic stress and ground temperature in the eastern tectonic knot in the Tibet Plateau.High-temperature true triaxial compression tests are performed on the samples using a self-developed testing device with five different loading directions and three temperature values that are representative of the geological conditions of the deep underground tunnels in the region.Effect of temperature and loading direction on the strength,elastic modulus,Poisson’s ratio,and failure mode are analyzed.The method for quantitative identification of anisotropic failure is also proposed.The anisotropic mechanical behaviors of the gneiss granite are very sensitive to the changes in loading direction and temperature under true triaxial compression,and the high temperature seems to weaken the inherent anisotropy and stress-induced deformation anisotropy.The strength and deformation show obvious thermal degradation at 200℃due to the weakening of friction between failure surfaces and the transition of the failure pattern in rock grains.In the range of 25℃ 200℃,the failure is mainly governed by the loading direction due to the inherent anisotropy.This study is helpful to the in-depth understanding of the thermal-mechanical behavior of anisotropic rocks in deep underground projects.

关 键 词：Anisotropic strength and deformation True triaxial compression Thermal mechanical coupling Deep rock mechanics High temperature rock mechanics 

分 类 号：TU45[建筑科学—岩土工程]