Study on water inrush mode and evolution mechanism of water channel in roof type goaf

Abstract

The roof type goaf water disaster in coal mine has strong impact and destructive force. It is of great significance to study the evolution law of water inrush channel of overlying strata under goaf water for the prevention and control of goaf water disaster. Taking the goaf water inrush accident of 8446 working face in a mine in Shanxi Province as an example, this paper uses similar simulation and numerical simulation methods to explore the coupling law between the structural failure of coal seam roof overburden and hydraulics, and reveals the morphological evolution mechanism of water inrush channel. The results show that the goaf water inrush process of roof has experienced the initial seepage stage, the fracture seepage stage and the pipeline flow water inrush stage. The initial seepage lags about 3 m behind the peak stress, and the average seepage velocity is 4.056 m/d. The hysteresis and seepage velocity can be used as the key early warning information of water inrush accident. Through the simulation of the fluid-solid coupling numerical model, the water inrush channel is located around the rectangular terrace compaction area, which is basically consistent with the actual water inrush position on site.

Keywords

• goaf water
• overburden destruction
• seepage velocity
• similar simulation
• rectangular terrace belt