工作面开切眼与顺槽交叉口顶板稳定性分析及加强支护范围的确定

针对某大型矿井工作面顺槽与开切眼的现场条件,采用数值计算方法,研究顺槽与开切眼交叉口项板的应力场和位移场分布特征,确定二次应力场叠加的影响范围及大小,并据此确定顶板加强支护范围及支护强度.研究结果表明:在交叉口顶板高度的煤体中形成了一定范围的围岩破坏区域,并在深部形成了应力集中带,铅垂应力分布图表明,在交叉口顶板上存在一个三边都为弧形的三角形卸压区域;交叉口处铅垂位移在顶板高度水平上在中央的铅垂位移最大,往四周方向延伸逐渐减小,直到煤体深部为零为止.因此建议:交叉口加强支护的范围应采用锚网支护,在围岩较破碎情况下建议采用锚网+W钢带+钢筋梯梁等措施联合支护,此处应加大锚杆支护的深度和密度;如果需要,应采用单体支柱之类的措施进行加强支护.

Roof Stability Analysis and Support Reinforce Extent Determination of Open-off Cut and Crossheading Intersection

Based on the situation of crossheading and open-off cut,using numerical calculation,the distribution of stress field and displacement field at the intersection roof of crossheading and open-off cut was studied to determine the range and size of induced stress filed superposition,and than to determine support range and intensity.The result showed: there appeared a surrounding-rock failure area in the intersection roof,a stress concentration area in the deep part;the vertical stress distribution map indicated an arc triangle pressure relief area on the intersection roof;the vertical disposition was maximum in the center at the roof level,decreased gradually into all directions,and became zero to the deep part of coal.Therefore,the anchor mesh should be adopted to reinforce the intersection and the combined support(anchor mesh + W steel belts + reinforced steel trapezium beam) should be used in the surrounding rock broken situation to strengthen the support depth and density;if necessary,the single prop and other measures could be used.