巷旁切顶对采场下位岩层垮落特征的影响机制

Influence mechanism of roadside roof cutting on collapse characteristics of lower roof in a stope

巷旁切顶打断了巷道与采场下位顶板的连续性,促进了采场顶板垮落形成碎石帮,深入研究切顶对采场下位岩层垮落特征的影响机制具有重要意义。对采场支架载荷进行了分析,并对上覆岩层建立了力学建模,明确了上覆岩层运动与典型位置采场支架载荷特征的关系。在此基础上,针对6个巷旁切顶的工作面,给出了典型位置支架的载荷数据,从而分析得到巷旁切顶对采场下位岩层垮落特征的影响机制。同时,建立了数值模型,分析了不同的切顶起始位置和下位顶板强度对下位岩层垮落特征的影响。结果表明,121工法的“垮落线”具有对称的弧形边界,110工法的“垮落线”在切顶侧向工作面充分移动,N00工法介于上述两者之间。此外,不同切顶起始位置和顶板强度条件下,切顶的作用效果存在差异。研究结果有利于进一步深化巷旁切顶对采场下位岩层垮落特征影响的认识。

The roadside roof cutting interrupts the continuity between the roadway and the lower roof, promoting the collapse of the lower roof to form a gravel gang. It is of great significance to study the influence mechanism of roof cutting on the caving characteristics of lower stope strata. In this paper, the stope support load was analyzed, the mechanical modeling of the overlying strata was carried out, and the relationship between the movement of the overlying strata and the stope support load characteristics at typical positions was clarified. On this basis, the load data of supports at typical positions were given for six working faces with roadway side roof cutting, so as to analyze the influence mechanism of the roadside roof cutting on the collapse characteristics of the lower strata in the stope. Meanwhile, a numerical model was established, taking into account the different starting positions of roof cutting and the strength of the lower roof, and further analyzed the effect of roadside roof cutting on the collapse of the lower strata.The results show that the "caving line" of the 121 method has a symmetrical arc boundary, the "caving line" of the 110 method is entirely moved to the working face on the roof cutting side, and the N00 method is between the above two. In addition, there are differences in the effect of roof cutting under different roof cutting starting positions and roof strength conditions. The research results are conducive to further deepening the understanding of the effect of roadside roof cutting on the caving characteristics of the lower stope strata.