含瓦斯煤弹性应变能计算新方法研究

为了探索含瓦斯煤破坏时释放弹性应变能的科学计算方法,针对硬岩与含瓦斯煤力学特征的差异,理论分析了常用冲击倾向性指标法计算弹性应变能的局限性。基于含瓦斯煤扩容力学特性,提出了以扩容临界点为界限,依据应力-体积应变曲线与横坐标轴围成的面积计算含瓦斯煤弹性应变能的新方法,并分别对硬岩和含瓦斯煤弹性应变能计算分析。结果表明,对于硬岩,常用冲击倾向性指标法和新方法计算结果基本一致,验证了本文提出的新方法的科学性;对于含瓦斯煤,常用冲击倾向性指标方法计算值远远大于新方法计算值。本文提出的“应力-体积应变”弹性应变能计算方法更能反映含瓦斯煤加载过程变形特征,为煤矿动力灾害的防控研究提供理论依据。

Study on Novel Calculation Method for Elastic Strain Energy of Gassy Coal

In order to explore the scientific method for calculating the elastic strain energy released when gassy coal was broken, the limitations of commonly used bursting liability index method for calculating elastic strain energy were theoretically analysed against the differences in the mechanical characteristics of hard rock and gassy coal. Based on the dilatancy mechanical characteristics of gassy coal, a novel method of calculating the elastic strain energy of gassy coal was proposed based on the critical point of dilatancy and the area enclosed by the stress-volumetric strain curve and the abscissa axis, and the elastic strain energy of the hard rock and gassy coal were calculated and analysed respectively. The results show that the common bursting liability index method and the novel method are basically the same for hard rock, and the novel method is proved to be scientific. For the gassy coal, the calculated value of the commonly used bursting liability index method is much larger than that of the novel method. The “stress-volume strain” elastic strain energy method proposed in this paper can effectively reflect the deformation characteristics of gassy coal loading process, which provides a theoretical basis for the prevention and control of coal mine power disasters.