煤层开采和瓦斯抽放引起的煤体损伤演化不仅使煤体力学性质发生改变,而且还影响煤与瓦斯的相互作用。本文基于损伤力学与多孔介质理论,并考虑煤体吸附瓦斯膨胀变形效应,建立了压缩条件下含瓦斯煤体的有效应力方程,得到了与含瓦斯煤体损伤演化相关的孔隙压有效应力系数和吸附有效应力。利用含瓦斯煤体有效应力方程和线弹性本构模型,计算分析了不同应力条件下含瓦斯煤体的变形与有效应力系数演化特征。结果表明,计算值与试验结果一致性较好,可以有效描述含瓦斯煤体的损伤力学行为。

The damage growth of coal induced by coal mining and gas exploitation conduces to not only the degradation of mechanical properties, but also the modification of interaction between coal and gas. Considering the swelling deformation of coal during adsorbing gas, the effective stress equation for gas-saturated coal under compression is built up based on damage mechanics and porous media theory. The pore pressure effective stress coefficient and adsorption effective stress related with damage evolution of gas-saturated coal are obtained. Then by using the effective stress equation and linear elastic constitutive model, the deformation and effective stress coefficient of gas-saturated coal are computationally analyzed with the different stress conditions. The computing value fits with the test result quite well, the fact indicates the equation is able to effectively describe the mechanical behavior of gas-saturated coal.