基于巷道顶板三维围压计算的锚索梁布置方式作用机制研究

Study on mechanism of anchor beam arrangement mode based on calculating confining pressure of 3-D roof

为分析锚索梁不同布置方式作用机制,以低围压下围岩峰后强度研究成果为基础和支撑,建立了支护系统对顶板围岩作用的三维力学模型,通过理论分析和推导得到了锚索梁(及其各种不同布置方式)、锚杆、锚索单独或联合作用下的顶板围岩围压计算公式。利用该公式,以赵楼煤矿千米深井巷道支护为工程背景,对让压型锚索箱梁4种不同布置方案进行算例分析,对比围压值及其分布范围可知:纵横组合方案在顶板围岩中形成的围压状态最佳,其次为纵向单梁方案,纵向双梁方案及横梁方案分列其后。该不同布置方案围压状态优劣顺序与现场试验巷道支护效果的优劣顺序一致。锚索梁支护系统不同布置方式作用机制在于,不同锚索梁布置方式在顶板围岩中形成的围压状态有明显差异,且该围压状态是决定支护方案效果的一个重要因素,两者正相关。

To analyze the mechanism of different anchor beam arrangement, the 3D mechanical model of support system acting on roof was established, based on the research of strength in the post-peak re-gion of surrounding rock under low confining pressure. And the confining pressure computing formulas of the roof under the independent action or combined action of bolts, anchors and anchor beam with different arrangement modes, were derived. Calculations of four layout plans of the yielding anchor rope box girder in the 1 000 m deep well of Zhaolou coal mine were analyzed. It is found that after the comparison of confining pressure values and distribution range, among the four programs, the confining pressure state formed in roof surrounding rock with a longitudinal-lateral program was the best, the lon-gitudinal single anchor beam program following, and the last two were longitudinal double anchor beam program and cross anchor beam program. The preferential order of the layout plans corresponds to that of the support effect of different support programs in field test. The mechanism of different anchor beam arrangement modes is that the difference of confining pressure states in roof made by different programs was significant, and the confining pressure state, which had a positive correlation with support effect, was an important influencing factor for support effect of program.