Study On Creep Law Of Deep Soft Rock Under Thermal-Mechanical-Chemical Coupling Effect

Deep soft rock engineering is the bottleneck engineering of underground engineering. Deep rock is in the multi-field coupling underground environment: high-temperature, high-stress and chemical corrosion. These physicochemical field coupling effects make deep rock show characteristics of soft rock:lager deformation, strong rheological properties and so on, which make deep rock engineering very unstable and difficult to support, and even bring construction and personnel security to serious threat. Therefore, from study on rock creep property, only single stress filed and two fields being studied is not enough. Thence, carrying out studies on creep law under thermal-mechanical-chemical coupling have very important theoretical significance and practical value to evaluate the rock engineering stability.In this article a method of combining experimental research, theoretical analysis and numerical simulation was used. To carrying out smoothly testing, the high temperature and high pressure triaxial environmental chamber is innovatively designed, and chamber structural analysis was conducted by using ANSYS software, and the correctness of the design was verified; To study creep law of deep soft rock under thermal-mechanical-chemical coupling effect, systematic experimental studies were carried out, the effects of temperature and chemical corrosion of the deep rock creep law under thermal-mechanical-chemical coupling were analyzed, and its mechanism was explored; Deep rock visco-elastic-plasticity nonlinear creep equations of considering temperature and chemical pH value influencing factors were established; T-M-C coupling controlling equations of deep rock were established; According to practical engineering background, numerical simulation analysis under thermal-mechanical-chemical coupling effect of deep tunnel of auxiliary shaft of Shandong Tangkou coal mine were carrying out.The main research contents of this article are as follows:1、 According to rock in actual underground, environment parameters were determined of underground2000, triaxial environmental chamber was designed according to materials mechanics of and mechanical design theory. Using Pro/E and ANSYS finite element analysis software, the rationality of the design was verified.2、 Carrying out studying on creep properties of deep shale under different temperature and chemical pH value, analyzing different temperature and chemical pH value effect of deep shale creep properties, exploring shale temperature and chemical pH value mechanism.3、According to testing results, visco-elastic-plastic components combination model was improved, the nonlinear part of the model was got by method of half nonlinear component improving and half theory:using theorical model describing linear rheology part, using nonlinear combination substitute conventional linear combination, visco-elastic-plastic nonlear creep model of considering temperature and chemical pH value influencing factor deep rock were established.4、 Based on porous media mechanics, T-M-C three fields coupling controlling equations of the temperature field and chemical corrosion effects were established. The water chemical etching porosity equations, the rock static equilibrium equations under three cases of thermo-elastic, the isotropic thermo-elastic and thermo-elasto-plastic, and temperature controlling equations were put forwarded.5、 As a background in engineering instance, using ANSYS software, numerical simulation analysis under thermal-mechanical-chemical coupling effect of deep tunnel of auxiliary shaft of Shandong Tangkou coal mine were carryed out, temperature and chemical pH value effects of deep tunnel creep law were analyzed.