Study On Mining Effect Of Fault And Engineering Application

The mine water calamity is one of the biggest obstacles to influence and restrict the coal production and output in our contoury.Especially in recent years, water inrush has become more serious as the mine continues to extend to the deep of earth,80 percent of water inrush accidents are caused by fault. A lot of engineering examples show that most of water inrush accidents are caused by mining effect. Therefore, the research of fault and surrounding rock deformation and damage law under the influence of mining became the key problem to prevenet water inrush through fault.This paper from the influence factors of water inrush through fault, based on the stratigraphic of HuaiBei coal mine and DaTun coal mine, build different models of fault, used the method of numerical simulation, study on the characteristics of mining effect of fault under the different impact factors. Combined with the priactice of the F6 fault in LongDong ore NO.21 coal mine and the F5 fault in the actual five mining area of RenLou mine, and analyzed the fault and surrounding rock deformation and damage characteristics under the influence of mining, and combined with the theoretical calculation, determine the waterproof pillar width and offer scientific basis for coal mining safety. The main conclusion and achievements are as follows:1) In the same mining condition, the different influence factors of the floor including faults (stress, the distance between fault and coal seam), their mining effect are different. The greater the horizontal stress is, the greater depth of the floor failure, when the horizontal stress is in 2 times of vertical stress.The fault "shielding" effect is obviously. The depth of damage in the floor are controled by fault, the closer distance of fault and coal seam, its control function is more obviously.When the value is greater than 2 times, the fault "shield" action disappeared, which the depth of damage in floor do not effect by fault.2) Research of the elements of the fault occurrence affect the mining effect of the roof by orthogonal experiment, concludes that the width of fault is the biggest influence factor on caving zone of roof, dip Angle is second,the divide is minimum. And the fault-dip is the biggest influence factor on fracture zone of roof, the width of fault is second, the divide is minimum. 3) The same coal seam are mined on both sides of fault, when the fault is normal fault, excavating on the hanging wall first, the additive effect of mining is significant. The width of footwall coal pillar should be more than the width of coal pillar when mined alone.Otherwise, the impact is not significant, it can be ignored. When the fault is reverse fault, excavating on the footwall first, the additive effect of mining is significant. The width of hanging wall coal pillar should be more than the width of coal pillar when mined alone. Otherwise, the impact is not significant, it can be ignored.4) Closed distance coal seam mining on one side of the fault, the additive effect of mining are mainly embodied in influencing the height of fracture zones. The width of upper coal pillars plays a decisive role for the lower part of pillar, when the upper seam pillar width is larger, the lower seam coal pillar width can be reduced accordingly.Figure [65] table [17] reference [51]...