加轴压卸围压下含瓦斯煤岩损伤变形的能量演化机制

采动影响下含瓦斯煤岩的损伤变形是一个极其复杂的非线性过程，单纯依靠传统经典弹塑性力学无法准确分析其破坏机理。针对此情况，通过试验研究了不同初始围压条件下含瓦斯煤岩的损伤变形特征，并分析了损伤变形与能量演化规律之间的内在联系。研究表明:初始围压越高，煤样破坏时强度越大，脆性破坏特征越明显，瓦斯流量急剧增加幅度越大，煤样破坏时积累的总能量和弹性应变能越多，且初始围压与弹性能之间满足对数函数关系。采用累积耗散能定义了煤岩损伤变量，并分析了不同阶段损伤与渗透率之间的演化关系。

Energy evolution mechanism for damage deformation of gas-containing coal rock under loading axial pressure and unloading confining pressure

The damage deformation of gas-containing coal rock under the influence of mining is an extremely complex nonlinear process,and it is impossible to accurately analyze the failure mechanism by simply relying on the traditional classical elastic-plastic mechanics. Aiming at this situation,the damage deformation characteristics of gas-containing coal rock under different initial confining pressures were studied by the experiments,and the internal relationship between the damage deformation and the energy evolution laws was analyzed. The results showed that the higher the initial confining pressure,the greater the strength of coal sample failure,the more obvious the brittle failure characteristics,the greater the sharply increase amplitude of gas flow,the more the accumulated total energy and elastic strain energy,and there was a logarithmic function relationship between the initial confining pressure and the elastic energy. The cumulative dissipation energy was used to define the damage variable of coal rock,and the evolutionary relationship between the damage and permeability at different phases was analyzed.