Aiming at backfill with crack under the thermo-mechanical (TM) coupling, the concepts of crack macro-damage, loading meso-damage, thermal meso-damage, and total damage of backfill were proposed. Based on the statistical damage theory, considering the coupling effects of temperature, load and initial crack, a damage evolution model of backfill with crack under TM coupling effects was established. Based on this, the strength criterion of backfill with crack considering the effects of thermal and mechanical coupling was constructed by multivariate function full differential method. The research shows that: (1) The theoretical curves of damage evolution model and strength criterion of backfill with crack under TM coupling are in good agreement with the test curves, which verifies the rationality of the model. (2) The initial thermal damage decreases first and then increases with increasing temperature, reaches a minimum value at 40°C, and generally shows a “V” -shaped distribution law. The coupling effect of temperature and crack aggravates the total damage of the backfill. (3) The strength criterion can reflect the relationship between the stress and strain of each limit state and the parameters of backfill with crack under different temperature conditions and can provide a certain reference for the evaluation of the stability of backfill with geological defects such as joints and crack in deep high temperature mines.

针对热机械耦合下的裂纹回填问题，提出了裂纹宏观破坏，加载细观破坏，热细观破坏和回填整体破坏的概念。基于统计损伤理论，考虑温度，载荷和初始裂纹的耦合效应，建立了TM耦合效应下裂纹回填的损伤演化模型。在此基础上，采用多元函数全微分法构造了考虑热力和机械耦合作用的裂纹回填强度准则。研究表明：（1）TM耦合作用下的损伤演化模型理论曲线和裂纹回填强度准则与试验曲线吻合良好，验证了模型的合理性。（2）初始热损伤先随温度升高而减小，然后随温度升高而增大，在40°C时达到最小值，并且通常表现出“ V”形分布规律。温度和裂纹的耦合效应加剧了回填的总破坏。（3）强度判据可以反映出不同温度条件下各极限状态的应力应变与裂缝回填参数之间的关系，可以为评价节理等地质缺陷回填的稳定性提供一定的参考。在深部高温矿井中破裂。