Research on the safety of coal mining beneath a river

Abstract

Aiming at the geological conditions of coal mining face under a collapsible river. Based on the analysis of the basic mining conditions and hydrogeological conditions of the mine, the theoretical analysis and numerical calculation of the height of the water-conducting fracture zone and the on-site monitoring of the surface movement and deformation law were combined. At the same time, the safety of coal mining under the river was calculated by the collapse column coal pillar protection method. A comprehensive study was conducted to determine the position of the secondary open-off cut of the working face under the influence of the collapse column. Furthermore, the remediation of the river channel and riverbank during mining beneath the river was studied. The results indicate that under these geological and mining conditions, the maximum height of the water-conducting fracture zone is 119 m, Under the condition of collapsible thick loose layer, δ0 is about 58.9°, γ0 is about 59.9°,β0 is about 56.5° . and the second open-off cut position should be located 55 m away from the collapse column. By adopting river protection measures such as composite geomembrane and gabion stone cages, the normal and safe operation of the river is ensured. The research results can offer theoretical foundations and technical support for addressing surface subsidence and ensuring safe underground mining.

Keywords

• Coal mining beneath a river
• Height of water-conducting fracture zone
• Second open-off cut position
• Surface movement and deformation
• River remediation