关键词: 瓦斯抽采, 动态响应, 混合物理论, Laplace变换, 理论解答

Abstract: The coal-rocks contain gas are assumed as gas saturated isotropic homogeneous media. The physical equations, geometric equations, continuity equations and dynamic control equations about the coal-rocks are established using the mixture theory. The length of the gas suction hole is much larger than the diameter. The dynamic response of gas suction hole in the coal-rock due to the action of negative suction pressures during the suction process can be simplified into a two-dimensional initial-boundary problem. The theoretical solutions in frequency domain and time domain are respectively derived with Laplace transform and inverse Laplace transform. The parameters of coal rocks and gas in a mine of Henan province are taken as examples. The dynamic response near the hole wall is numerically calculated. The dimensionless radial displacements, radial stresses and circumferential stresses are analyzed. Finally, some conclusions are drawn as follows. The dimensionless radial displacements and stresses are mainly concentrated at a local area near the gas suction hole. The area increases with the suction time. Large and volatile circumferential stresses are generated at the hole wall. They increase as the negative suction pressures increase.

Key words: gas suction, dynamic response, mixture theory, Laplace transformation, theoretical solutions