Research on development height of overlying water-conducting fault zone in shallow seam mining in Shennan Mining Area

Abstract

Aiming at the fact that the water-conducting fissures in the overlying rock may cut through aquifers and induce water inrush disasters by repeated mining of shallow-buried and short-distance coal seams in Shennan Mining Area, this paper adopts the methods of similarity simulation, numerical simulation and field drilling measurement to study the short-distance 1-2 coal and 2-2 coal mining overlying rock water-conducting fracture zone development law. When the 1-2 coal is fully mined, the height of the overlying fissure zone is about 50 m, and it is not connected with the upper quaternary loose pore water and the Jurassic weathered bedrock confined water; when the 1-2 coal and 2-2 coal are in repeated mining, the theoretical prediction of the water-conducting fault zone is about 136 m, the development height of the overburden fault zone is about 140 m according to the physical and numerical simulation, and the height of the water-conducting fault zone measured by the field borehole is about 135 m. The three are very consistent, and the fault zone is connected with the confined water of Jurassic weathered bedrock. The measures of dredging confined water from mining roadway to weathered bedrock of Jurassic at 300 m in advance working face are proposed. The field practice shows that no accident of water inrush and sand collapse occurs in the process of coal mining.

Keywords

• shallow buried coal seam
• close coal seams
• repeated mining
• water-conducting fracture zone height
• water and sand inrush