Surface crack and sand inrush disaster induced by high-strength mining: example from the Shendong coal field, China

Abstract

Sand inrush disaster and ground destruction induced by high-strength mining in the Shendong coal field seriously threaten the normal operation of the mine and cause significant property losses and environmental disruption. The physical simulation experiment demonstrate that the roof of high-strength mining working face can be regarded as a “step beam” structure and broken by sliding instability. The vertical damage state of overlying strata is summarized into three types: slightly, severely and very severely damage. On the basis of in situ data of the working face with the mining height greater than 3 m, the prediction formulas of the caved and fractured zone heights are given. The vertical damage types of working faces 22407 and 22402 are analyzed. Owing to the sliding instability of the roof and the thin bedrock, the surface stepped crack has become widely distributed above the high-strength mining working face. The sand inrush of working face 22402 can be interpreted by the very severely damaged of overburden and the thick aeolian sand aquifer. This work can be used to improve the understanding of mining-induced disaster and establish a disaster prediction model.