The mechanism analysis of sand inrush disaster in Shen-Fu mining area's shallow seam

The characteristics of Shen-Fu mining area's coal is shallow seam and being, covered with water, the water and sand maybe inrush into gob when the coal is mined. On the base of analysis, the hydrology geological conditions and, the engineering geological conditions of shallow seam, the conclusion is drawn that it must has four conditions to occur sand inrush in shallow seam mining. The law of roof rock's moving has been, studied and if the rock will occur rotating has been judged through the analysis of combinatorial key strata's parameters in shallow seam. The possibility of rock occurring slide after contacting waste has been discussed through the analysis the force of broken rock. According to them rock rotating angle, the contact surface height of broken rock's column has been calculated, and the reasonable contact surface height to ensure not occurs sand inrush has been puts forwarded. These conclusions am confirmed by 1203 coalface in which water inrush occur but sand inrush not occur when mining in Shen-Fu mining area in Shaanxi.