沿空留巷矿压显现周期性机制研究

沿空留巷保留巷道中的矿压显现存在强烈区和缓和区周期性交替的现象,通过建立沿空留巷结构力学模型,分析了此现象与工作面端头弧三角形悬板的关系。研究表明:周期来压时,工作面顶板断裂会在沿空巷道上方产生弧三角形悬板,悬板最大悬顶距对应位置的巷道矿压显现相对强烈,并且随工作面推进矿压显现强烈区以周期来压步距为步距跳跃前移。在上述研究基础上,提出弧三角形悬板位置预测与实测方法,并以东滩煤矿3203工作面沿空留巷为工程背景,通过矿压观测对矿压显现程度周期性现象和弧三角形悬板位置进行了验证,提出了分阶段不等强支护方式,为留巷滞后支护设计提供了依据。

Mechanisms of Strata Behaviors Periodicity for Gob-side Entry Retaining

A periodic ahernating phenomenon exists between strong area and weak area of the strata behaviors in the maintained roadway of the gob-side entry retaining. The relation between this phenomenon and suspended triangle roof plate with curve side on the end of sub level caving mining face was analyzed by building the structure mecha nics model of gob-side entry retaining. The study shows that： suspended triangle roof plate with curve side are produced above gob-side entry by roof fracture in the working face during the periodic weighting;the strata behaviors is relatively strong in the place where the roof hanging distance of hanged-plate is the largest; the strong area of the strata behaviors skips forward with the periodic weighting distance as the working face advances. Then the location prediction and measurements of suspended triangle roof plate with curve side were raised based on the above resuhs. The periodic phenomenon of the strata behaviors and the location of the suspended triangle roof plate with curve side were tested through pressure observation with the gob-side entry retaining in 3203 working face of Dongtan Mine for further evidence.