Mining Pressure Behavior and Pre-warning Index of Roof Cutting and Supports Crushing in Fully-mechanized Top-coal Caving Face of Coal Mine
In the fully-mechanized top coal caving mining of extra-thick coal seams,due to the limitations of technical equipment and other conditions,it is difficult to form a stable structure during top coal caving due to the high looseness of the roof,which can easily cause large-scale roof cutting collapse at the working face,instant impact on the supports,damage to the hydraulic support structures,and severely affect on the safe and efficient mine production.Taking the F6218 fully mechanized top-coal caving face of Buliangou Coal Mine as the engineering back-ground,this study analyzed the basic support conditions,including initial support force,the opening of the safety valve,and working resistance frequency,through measured data.The study revealed the mine pressure behavior of the working face and established a pre-warning index sys-tem for roof cutting and support crushing disasters suitable for this mine.The results show that the pre-warning index thresholds for Buliangou Coal Mine are 40 kN/min of cyclic resistance in-crease rate,50％of safety valve opening rate,1.4 of dynamic load coefficient,500 mm of movea-ble column shrinkage,not less than 25 MPa in front column of the support,and not less than 90％of the qualification rate of the front column,not less than 20 MPa in rear column,and not less than 90％of the qualification rate of the rear column.
mine pressure behaviorpre-warning indexes of roof cutting and supports crushingworking condition of supportfully mechanized top-coal caving miningextra-thick coal seam
万方数据
维普
