1. Geotechnical Engineering Center, Shandong University, Jinan 250061, China;
2. Power China Huadong Engineering Corporation Limited, Hangzhou 310014, China ;
3. Logistics Department of Shandong University, Jinan 250100, China
Abstract：With the increase of excavation depth in underground engineering, the high ground temperature and high geostress may lead to significant creep deformation of rock. Hence, it is very important to study the thermo-mechanical coupling creep characteristics of rock to ensure the construction and operation safety of underground cavern. In this study, the gneissic granite in high temperature section in diversion tunnel of Xinjiang Qirehataer hydropower station was taken as the research object, and the creep law of gneissic granite affected by temperature was obtained through the triaxial creep test under different temperatures and stress paths. Based on the creep test results, the thermo-visco-elastoplastic damage creep model considering the thermo-mechanical coupling effects was put forward, the thermal-visco-elastoplastic damage creep constitutive relation for gneissic granite was established, the damage creep equations in 1D and 3D cases were derived, and the creep mechanical parameters of rock were obtained based on the inverse analysis. According to the established thermal-visco-elastoplastic damage creep model，the influence laws of temperature on the creep characteristics of rock were obtained under the low, medium and high geostress conditions, respectively. The research results provide an important theoretical basis for the long-term stability analysis on the underground engineering.
