Simulation Study on the Recovery of Residual Ore Pillars under a Complex Mining Cavity Cluster Influenced by Multiple Factors
There has been a controversy over the recovery of 6～8 security pillars of Ⅰ belt vein in a tungsten mine under the influence of fault cutting and multiple veins.This paper adopts theoretical analysis and numerical calculation to analyze the stability of the mining cavity and the feasibility of recovering the residual security pillars,on the basis of which three residual pillar recovery schemes are proposed and compared and analysed.The results show that:The relative stability of the mining cavity around the pillar,the release of strain energy within the pillar itself,the reduction of the risk of ground pressure disasters brought about by the recycled pillar,and reduce the risk of ground pressure disaster brought about by subsequent recovery,in which the misalignment damage leads to a reduction in the overall stiffness of the pillar,and the mining pillar can not be well supported,and can be considered for recovery.After the residual ore column is mined back out of the ore,the inter-column stress concentration between the fault-cut residual ore return area and the original left and right sides of the mining cavity is more obvious,and there is also a large area of shear damage plastic zone,which indicates that there may be a risk of shear dam-age in the process of the residual ore mining back out of the ore.Partial filling of the fault-affected hollow area on both sides of the security pillar can effectively suppress the stress concentration phenomenon,weaken the loosening tendency of the side states,and effectively reduce the slip tendency of the upper and lower discs along the fault in the residual ore recovery area.It can realise the safe and economic recovery of the residual security pillar.
numerical simulationsecurity pillarsresidual ore recoverystability of mining cavity
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