低温下煤岩体力学特性实验研究

Experimental Study on Mechanical Properties of Coal Rock Mass at Low Temperature

基于岩石低温损伤问题，为进一步研究煤岩在低温下力学特性，选取黄陵煤岩样，冻结到不同温度（-60—20℃）后进行单轴压缩实验，研究力学性质及破坏特点。实验结果表明：低温下煤岩体积明显收缩，温度越低其体积收缩程度越大，平均收缩率约为0．02mm／cc；根据曲线图采用面积积分法量化出各温度下煤岩破坏做功总值以及各阶段吸收的能量；煤岩体的单轴抗压强度随着温度降低有增加趋势，但当温度低于-40℃后趋于稳定；煤岩随温度降低逐渐呈现脆性增强，塑性减弱趋势，其破坏以类似岩片崩落为主。

On account of the problems that the rocks are damaged at the low temperature, for the further research on the mechanical properties of the coal and rock mass at the low temperature, the samples of Huangling coal and rock mass were selected and frozen to the different temperatures between - 60℃ and 20 ℃ Then the uniaxial compression about them was experimented for the study on the mechanical properties and fracture characteristics. The resuhs are as follows ： the volumes of the coal and rock mass obviously shrink at the low temperature. The lower the temperature is, the larger the shrinkage of the volume is, the average rate of which is about 0.02 mm/℃ ; according to the curve graph, the area integral method was adopted to quantify the work value caused by the damage of the coal and rock mass at the different temperatures and the absorbed energy in each stage ; the strength of the uniaxial compressive increa- ses with the decrease of the temperature, but the coal and rock mass trend to be stable when the temperature is lower than - 40℃; with the decrease of the temperature, the coal and rock mass gradually present more brittle and weaken their plasticity, which causes some damage such as rock caving.