含瓦斯煤岩卸围压变形特征及瓦斯渗流试验

运用自制的含瓦斯煤热流固耦合三轴伺服渗流实验装置，进行了含瓦斯煤岩卸围压瓦斯渗流试验，研究其卸围压过程中的变形和瓦斯渗流特性。研究结果表明，卸围压试验煤样破坏形式是以剪切破坏为主的张剪复合破坏。卸围压过程中，含瓦斯煤岩围压-应变曲线可以分为3个阶段：屈服前阶段、屈服后阶段、破坏失稳阶段。渗透率-应变曲线与围压-应变曲线呈现出明显的对应关系，表明围压对煤岩的变形和渗透率有重大影响，煤岩渗透率的变化与煤岩的变形损伤演化过程密切相关。卸围压后，含瓦斯煤岩的泊松比立即转为向变大的方向发展，变形模量立即转为向变小的方向发展，并在卸围压过程中发展的趋势保持不变。

Experiment of deformation property and gas permeation of containing gas coal under confining pressure unloading process

Using self developed “Triaxial Stress Thermal hydrological mechanical Coal Gas Permeameter”,the gas permeation experiment of containing gas coal was carried out under the process of unloading confining pressure and deformation of coal and property of gas permeability were studied.The experimental results show that the failure of coal in the experiment of unloading confining pressure is a tension shear combined failure,mainly in a form of shear failure.During the unloading process of confining pressure,the curves of confining pressure verses strain can be divided into three stages:pre yielding stage,after yielding stage and destabilization failure stage.The permeability strain curves are obviously corresponding with the confining pressure strain curves,which indicate that the confining pressure has an important effect on deformation and permeability of coal and that the variance of permeability is tightly relative with deformation process of coal.After the confining pressure unloading process began,Poisson’s ratio turn to increase,deformation modulus decrease,and their changing trends keep invariable during the unloading process.