大采高工作面过空巷群顶板破断及矿压规律研究

为解决大采高综采工作面快速通过大断面空巷群,避免发生冒顶压架问题,以哈拉沟煤矿22311综采工作面过26条空巷群为研究对象,采用理论研究、数值模拟以及现场监测等方法,研究了综采工作面过空巷群期间空巷失稳机制及基本顶破断规律,模拟了综采工作面过空巷期间采用泵送支柱支护效果,监测了综采工作面过空巷期间顶板下沉量及压力情况,最终22311综采工作面安全顺利通过了26条大断面空巷群。研究表明:空巷失稳主要是由基本顶超前破断引起的,其次是由于空巷支护不足导致的,泵送支柱支护应具有可切割、大断面、高承载与让压变形特征。采用"泵送支柱+锚索+W钢带"联合支护方式,使支柱与顶底板围岩处于协同作用状态,可保证综采工作面安全通过大断面空巷群。

Study on the law of roof breakage and mine pressure passing large cross-section gob group in the fully-mechanized face with high mining height

In order to solve the problem of roof fall when passing through large section gob groups in the fully-mechanized working face with large mining height and avoid the problems of roof falling,the 26 roadway groups in No.22311 comprehensive mining face of Halagou coal mine are taken as the research object. Numerical simulation and on-site monitoring methods were used to study the instability mechanism of gob and the basic law of roof breaking when passing through the gob groups in the fully mechanized working face. The supporting effect of pumping pillar is adopted when passing through the gob of the fully mechanized coal face,and the roof subsidence and pressure are monitored by instruments. Finally,No.22311 fully-mechanized mining face passes 26 large section gob groups safely and smoothly. The research shows that the instability of the roadway is mainly caused by the advance breaking of the basic roof,followed by the insufficient support of the roadway. The support of the pumping pillar should have the characteristics of cutting,large cross-section,high load bearing and yield deformation. The combined support mode of " pumping pillar + anchor cable + W steel strip" is adopted to make the pillar and the surrounding rock of the roof and floor in a synergistic state,which can ensure that the fully mechanized working face can pass through the large cross-section roadway group safely.