关键词: 循环扰动, 高温, 砂岩, 力学特性, 岩爆倾向性, 破坏特征

Abstract: This paper aims to reveal the rockburst mechanism of sandstone under cyclic disturbance and high temperature. The uniaxial compression tests and CT scan tests on sandstone after different cyclic amplitudes and temperatures were conducted to investigate the mechanical properties, rockburst tendency and failure characteristics of sandstone specimens. The rockburst tendency and failure characteristics of specimen were analyzed. Results showed that the effects of high temperature and cyclic disturbance on the mechanical properties and rockburst tendency of sandstone were significant. The compressive strength, elastic modulus and rockburst tendency of specimens without cyclic disturbances tended to first increase and then decrease as temperature increased, and the threshold temperature was 200 ℃; while those with cyclic disturbances decreased as temperature increased, and the mechanical properties and rockburst tendency of sandstone decreased with increasing the cyclic stress amplitude. The uniaxial compression failure mode shifted from splitting failure to shear failure with the increase of cyclic amplitude and temperature, and the rockburst tendency had a good negative relationship with the three-dimensional fractal dimension of fracture. In addition, the effect of high temperature on the mechanical properties, rockburst tendency and failure degree of sandstone was stronger than that of cyclic disturbance. The research results can provide theoretical basis and engineering reference for the prevention and control of rockburst in high temperature engineering.

Key words: cyclic disturbance, high temperature, sandstone, mechanical properties, rockburst tendency, failure characteristics