Study on dynamic development of surface fractures in shallow coal seam mining through gully

Abstract

In order to study the dynamic evolution law of surface fractures in different positions when coal seam is mined through a gully, the development characteristics of surface fractures are studied by using similar material simulation experiment and VIC-3D system, taking 14210 working face of a mine in northern Shaanxi Province as the prototype. The results show that the width of surface cracks in the gully increases first, then decreases rapidly and finally closes. The width of surface cracks on the left slope and the right slope increased first, then decreased slightly, and then tended to be stable. According to their development location and strain changes, the surface fractures can be divided into three categories: left slope tension surface fracture, gully compression surface fracture and right slope tension surface fracture. Based on the safety prediction of 14210 working face mining through gully, it can be seen that the factors leading to Wulanbulagou spring water flooding into the working face during mining through the gully can be roughly divided into four factors: crack width, crack distribution density, water level in gully and advancing speed of working face.

Keywords

• mining through gully
• surface fractures
• vic-3d system
• law of dynamic evolution
• overburden rock strain