Abstract Coal seam construction disturbances or gas depressurization and extraction can cause rupture damage of the surrounding coal and rock. The damage not only changes the structural property and mechanical behavior of the coal and rock, but also changes the physical parameters of the coal and rock. The gas migration not only changes the pore pressure, but also changes the effective stress and the adsorption and expansion deformation of coal seams, which resulted in the damage evolution and accumulation of coal and rock. The temperature change will not only affect the stress distribution of coal and rock, but also affect gas adsorption properties and diffusion capacity. In fact, the gas extraction is a multi-field coupling process of the coal-rock damaged field, temperature field and gas seepage field. In this paper, coal and rock is considered as a double medium of pore and crack. The damaged variable is defined in view of the damaged and failure characteristics of coal and rock. The damaged constitutive equations of coal and rock are established considering the effects of gas pressure and temperature. On this basis, the gas diffusion and seepage coupling equations in damaged coal and rock are derived. Based on the basic theory, the two development of the finite element source program is carried out by using the FORTRAN language. This program was developed to consider the temperature, gas seepage and deformation of coal and rock. Based on this program, the work process of gas drilling in coal mine is simulated and the dynamic evolution process of the damaged field of coal and rock and the permeability of the gas are quantitatively described. These achievements have extremely important theoretical guidance to guide the design of gas extraction in coal seams and improve the gas drainage rate.

中文翻译：

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采气过程煤岩破坏场和渗流场三维动态演化分析

摘要 煤层施工扰动或瓦斯降压抽采会引起周围煤岩的破裂破坏。损伤不仅改变了煤和岩石的结构特性和力学行为，而且改变了煤和岩石的物理参数。瓦斯运移不仅改变孔隙压力，而且改变煤层的有效应力和吸附膨胀变形，导致煤岩损伤演化和堆积。温度变化不仅会影响煤岩的应力分布，还会影响瓦斯吸附特性和扩散能力。实际上，瓦斯抽采是煤岩破坏场、温度场和瓦斯渗流场的多场耦合过程。在本文中，煤和岩石被认为是孔隙和裂缝的双重介质。损伤变量是根据煤岩的损伤破坏特性定义的。建立了考虑瓦斯压力和温度影响的煤岩损伤本构方程。在此基础上，推导了受损煤岩中的气体扩散渗流耦合方程。在此基础理论的基础上，利用FORTRAN语言进行了有限元源程序的二次开发。该程序的开发考虑了煤和岩石的温度、瓦斯渗漏和变形。基于该程序，模拟了煤矿瓦斯钻井作业过程，定量描述了煤岩破坏场和瓦斯渗透率的动态演化过程。