论文部分内容阅读
为研究脉动孔隙水压作用下低透性松软煤岩在不同三轴加压条件下的损伤变形规律,采用RLW-2000M煤岩流变仪进行了不同轴压和围压系列下的试验研究。结果表明:煤岩破坏的应变曲线具有先疏后密再疏的变化规律,且累积应变和残余应变随着围压的增加而减小,而随着轴压的增加而增大;平均单次耗散能随着围压的增加而减小,随着轴压的增加而增加,其关系符合指数函数变化特征;采用累积耗散能计算了煤岩破坏过程中的损伤变化特征,并采用Logistic方程逆函数对其进行了拟合分析,得到了煤岩损伤演化模型,为预测煤岩破坏周期提供了依据。研究结果为具有不同地应力条件下的低透气性松软煤层施工脉动水力压裂提供了一定的理论依据。
In order to study the damage and deformation law of low permeability and soft coal under pulsating pore pressure under different triaxial compression conditions, the RLW-2000M coal-rock rheometer was used to conduct experiments under different axial compression and confining pressures . The results show that the strain curves of coal and rock failure have the rule of thinning and then thinning, and the cumulative strain and residual strain decrease with the increase of confining pressure and increase with the increase of axial pressure. Dissipative energy decreases with the increase of confining pressure and increases with the increase of axial pressure, and the relationship is in accordance with the exponential function. The cumulative dissipation energy is used to calculate the damage characteristics during the process of coal and rock failure. Logistic The inverse function of the equation was fitted to the analysis, and the damage evolution model of coal and rock was obtained, which provided the basis for predicting the failure period of coal and rock. The results provide some theoretical basis for the pulsating hydraulic fracturing of low permeability and soft coal seam with different ground stress.