Study on overburden failure characteristics and surface water infiltration law of coal seam mining through gully

Abstract

In order to analyze the overburden failure characteristics and surface water infiltration law of coal seam mining through gully, the typical working face of coal seam mining through gully is selected as the research object. Based on the engineering geological conditions of typical working face and the physical and mechanical properties of strata, the numerical model of actual strata is established by UDEC, and the overburden failure characteristics of coal seam mining through gully are studied. The results show that the height of water-conductive fractured zone is 230-250 m by numerical calculation and 225-245 m by field measurement. By extracting mining fissures of overburden and introducing them into COMSOL, the numerical calculation model of surface water infiltration after coal seam mining is constructed, and the law of surface water infiltration to the working face along the mining fissures is analyzed. The calculation results show that when the working face is advanced to 200, 250 and 300 m, the water-conductive fractured zone connects with the surface, and the surface water infiltrates into the working face along the fracture, and the stable water quantity is 10.4, 14.3 and 19.7 m3/h respectively. Finally, taking the working face advancing to 300 m as an example, the stable water quantity of working face obtained by numerical calculation and field measurement is compared and analyzed, and the difference between the two results is small.

Keywords

• through gully mining
• overburden failure
• numerical model
• infiltration of surface water
• stable water volume