Study the impact of 9310 working face mining on −670 water sump

Abstract

In order to research on the impact of water sump under seam floor. by mining 93 upper 10 working face in Nantun Coal Mine, numerical simulation and theory study are carried out in this paper. In the theoretical study, from the failure pattern of coal floor, criterion is put forward, that is whether the water sump is affected or not is existed in the overlap with floor failure, based on “down three zone”, and empirical and theoretical formula showed that −670 was out of floor failure district, within little influence; Starting from the propagation rules of mine pressure of floor, bearing stress in increased-stress zone were dividedly into point load and triangular, the mine pressure of water sump is calculated based on Boussinesq formula, and the result showed that mine pressure of water sump was much less than 5 percent of original rock stress. In the numerical simulation study, the result showed that the experimental value is in consistent with theory; maximum subsidence value of the water sump roof was about 4mm, maximum horizontal displacement is close to the face was about 14mm, and roadway displacement is smaller. All above could make conclusion that mining 93 upper 10 working face has little effect on −670 water sump under seam floor.