“充填体-煤柱”复合承载体稳定性分析

Stability analysis of“filling body-coal pillar”composite bearing body

为研究部分充填开采中"充填体-煤柱"复合承载结构稳定性以沙曲矿4901工作面为工程背景,通过实验室试验探究了复合承载体承载的应力变化及破坏特征,采用数值模拟的方法,将复合承载体分为4类,分析了在不同类型、宽度、高度及不同强度充填体与煤柱下承载体的稳定性。结果表明:随着承载体宽度增加,弹性区宽度明显增大,承载体宽度为30 m比宽度20 m时的弹性区宽度平均增加6.02%左右,宽度为40 m比宽度30 m时的弹性区宽度平均增加约34.35%;4类复合承载体中第Ⅳ类承载体与其他3类相比塑性区宽度相对较小,且随留充比增大始终保持在小范围内波动,稳定性效果最好;随着承载体高度增加,稳定性减弱,但充填体和煤柱强度增大,承载体稳定性增强。

In order to study the stability of the “filling body-coal pillar”composite bearing structure, the 4901 working face of Shaqu Coal Mine is taken as the engineering background, the stress changes and failure characteristics of the composite bearing body were explored through laboratory tests. The composite bearing body was divided into four categories by means of numerical simulation. The stability of the supporting body under different types, widths, heights and different strengths of the filling bodies and coal pillars is analyzed. The results show that: with the increase of support width, the width of the elastic zone increases significantly. The average width of the elastic zone increases by about 6.02% when the width of the support is 30 m than the width of 20 m, and the average increase of the width of the elastic zone by about 34.35% when the width is 40 m and the width of 30 m. Compared with the other three types of the four types of composite supports, the width of the plastic zone of the type IV support is relatively small, and it keeps fluctuating within a small range as the retention charge ratio increases, and the stability effect is the best. As the height of the support increases, the stability decreases, but the strength of the filling body and coal pillars increases, and the stability of the support increases.