Simulation on the Deformation of Gas Pipeline in Steep Seam Goaf
To explore the impact of the goaf formed by steep coal mining on the safe operation of the overlying gas transmission pipeline,a three-dimensional numerical model was established for the goaf of a coal seam based on FLAC3D software.The characteristics of geological settlement and pipeline displacement for the actual coal mine goaf were explored.In addition,the impact of steep coal seams with different dip angles and mining depths on the deformation of the overlying gas transmission pipeline was also studied.The results show that an collapse area above the coal seam slope with the largest depth of 1.54 m is formed after mining for 100 m to the five steep coal seams in the coal mine area.The soil and rock in the collapse area mainly move horizontally and vertically downward towards the coal seam.The vertical displacement of the pipeline near the goaf is greater than the horizontal displacement,while the horizontal displacement of the pipeline far away from the goaf is greater.With the decrease of dip angle of steep seam and the increase of mining depth,the downward settlement of the pipeline increases significantly,and the position where the maximum settlement occurs gradually approaches the direction of the seam.