Abstract:

In order to meet the challenge of the high ground temperature environment of deep mining，realize the real simulation of the environment，and improve the high ground stress-high ground temperature coupling capability of the true triaxial test equipment，the research and development of the ground temperature simulation platform of the rock true triaxial test machine has been carried out. The exploration and establishment of three kinds of heating schemes for the ground temperature simulation platform are the six-sided heating rod heating scheme based on solid medium heat transfer，the ring heater heating scheme and the liquid heat transfer heating scheme based on liquid medium heat transfer. Through the establishment of a true triaxial high ground stress-high ground temperature coupled loading program evaluation system combining numerical simulation （COMSOL），coefficient of variation method （RSD） and ideal solution for multi-attribute decision-making problems （TOPSIS），comprehensive indicators for three heating programs evaluation and scheme optimization. In order to obtain the best test results close to reality，the five basic evaluations of the quality of the evaluation plan are the uniformity of heating on the rock surface，the heat dissipation from the outside of the pressurized rod，the average heating rate of the rock sample，the strain value of the pressurized plate and the economic cost index. The COMSOL Multiphysics simulation software was used to simulate three heating schemes. Through the coefficient of variation method，the simulated data were objectively assigned，and the corresponding index values ??were brought into the TOPSIS model for comprehensive evaluation. The evaluation results show that the comprehensive evaluation indexes of the three schemes of six-sided heating rod heating，ring heater heating，and liquid heat transfer heating are 0.4288，0.9447 and 0.5532，respectively. The heating method of the ring heater is consistent with a positive ideal solution. The closeness degree reaches 0.9447，which is the optimal decision after comprehensively considering the five indicators. This evaluation system combines theoretical methods，numerical calculations and numerical simulations，and provides a reliable theoretical basis and experimental basis for finding the optimal heating scheme for true triaxial test equipment. The instrumental research on the coupling capability of ground temperature is of guiding significance.

Key words: deep mining environment, true triaxial ground temperature simulation platform, heating scheme, numerical simulation, RSD method, TOPSIS model