Height and detection of water flowing fractured zone in fully mechanized mining area

摘要

Coal mining like mining underneath buildings, roads, or waters changes the distribution of stress in rock mass, resulting in deformations between the roof and the surface, as well as crisscrossing fractures in the mining rock mass. These fractures and deformations affect the mechanic behaviors of the rock mass, and to some extent control its stability. As mining continues, stress balance will be lost, which may lead to collapsing of the rock mass around stope. Therefore, the monitoring of water flowing fracture zone of overlying strata is a vital problem. This paper studies the relationship between the water flowing fracture zone and mining by taking the fully mechanized mining underneath waters as an example. It concludes that the variations and distribution of fractures in the mining rock mass can be revealed by P- and S-wave seismic survey, which ensures miming of coal seam safely. S-wave reflection survey can be used to detect the formations with water flowing fractures and characterize the development degree of the fractures. The validity of the proposed method was verified by drilling. The proposed method provides support for mining of coal seam of over 10m at onetime under water reservoir.