低标号充填体对采矿环境结构稳定性作用机制研究

Action mechanism of low-grade backfill on stability of mining environment structure

运用ADINA有限元分析软件,计算分析了3种不同充填高度时的低标号充填体对采矿环境结构稳定性的作用机制。结果显示,分层内随着充填高度增加,结构稳定性具有如下规律:(1)人工顶柱拉应力最大值逐步降低,受力状况逐步得到改善;(2)人工矿柱拉应力首先转化为压应力,然后逐步增大,承载能力逐步得到提高,但达到某一充填高度后,人工矿柱的承载能力增长缓慢,继续充填对提高矿柱承载能力意义不大;(3)人工底柱由受矿柱的挤压作用转变为受充填体的重力作用,拉应力最大值呈现先降低后上升变化规律。综合考虑经济、安全等因素,低标号充填体存在一个最合理的充填高度(2.8m)。研究结果为采矿环境结构安全施工提供了科学依据。

The action mechanism of low-grade backfill with three kinds of different filling height on the stability of mining environment structure was analyzed by ADINA finite element analysis code.The results show that the stability of a layer structure with the increasing of filling height has some rules as follows.（1） The highest value of tension stress of artificial top pillar decreases gradually,and stress conditions has been improved.（2） The tension stress status in artificial pillar transforms into the compressive stress status,and the value of compressive increases gradually;and the carrying capacity has been improved gradually;however the filling height is beyond a certain height,the carrying capacity of the artificial pillar grows very slowly;and It is not too much significance to improve the carrying capacity only by the action of low-grade backfill.（3） The squeezing action on the artificial bottom pillar from artificial pillar transforms to the artificial bottom pillar into gravity action from the low-grade backfill,the largest value of tension stress of the artificial bottom pillar appeares the change rule that increasing at the beginning then reducing. Considering the economic,security and other factors,low-grade backfill has the most reasonable height（2.8 m） in the filling scope. This study provides the basis foundation for the safety construction of the mining environment reconstruction structure.