不同含水率下砂岩的冲击倾向性试验研究

Experimental study on bursting liability of sandstone under different water content

为评估不同含水率下煤层顶板砂岩的冲击倾向性,进行含水率条件下砂岩单轴压拉试验,计算其脆性系数、动态破坏时间、弹性能指数、冲击能指数和弯曲能量指数,并评价其作为冲击倾向性指标的适用性。结果表明砂岩强度随含水率的增加弱化明显,单轴抗压、抗拉强度降幅分别可达39.4%和22.9%,评价结果表明脆性系数、弹性能指数、冲击能指数与含水率的拟合程度较差,而动态破坏时间和改进的弯曲能量指数可作为含水率条件下煤层顶板的冲击倾向性指标。

In order to determine the bursting liability of coal seam roof sandstone under different water content,by carrying out the uniaxial compression and tension test of sandstone under moisture content,the brittleness coefficient,dynamic failure time,elastic energy index,bursting energy index and bending energy index of sandstone are obtained,and their applicability as bursting liability index is evaluated.The results show that the strength of sandstone weakens obviously with the increase of water content,and the uniaxial compressive strength and tensile strength decrease by 39.4%and 22.9%respectively.The evaluation results show that the fitting degree of brittleness coefficient,elastic energy index and impact energy index with water content is poor,while the dynamic failure time and the improved bending energy index can be used as the burning liability index of coal seam roof under water content condition.