Destruction features in floor caused by mining activity: with Tuanbai mine as example

The 10^th and 11^th coal seams in Tuanbai coal mine are suffering from the danger of water inrush from Ordovician karst water during mining. The key technical problems of coal mine floor water hazard control are the study on damaged areas of floor and the effect of ground pressure and water pressure on floor. Furthermore field measurement is reliable research method to master the floor damage regularity. The 10^th coal seam was selected as the monitor object, the influence scope and fracture depth were studied by water pressure tests. The results show that, the damage depth of 10^th coal is from ten meters to twelve meters, and influence scope are forty meters, the peak is from six meters to twenty meters.