Waste-filling in fully-mechanized coal mining and its application

A fully-mechanized coal mining (FMCM) technology capable of filling up the goaf with wastes (including solid wastes) is described. Industrial tests have proved that by using this technology not only can waste be re-used but also coal resources can be exploited with a higher recovery rate without removing buildings located over the working faces. Two special devices, a hydraulic support and a scraper conveyor, run side-by-side on the same working face to simultaneously realize mining and filling. These are described in detail. The tests allow analysis of rock pressure and ground subsidence when backfilling techniques are employed. These values are compared to those from mining without using backfilling techniques, under the same geological conditions. The concept of equivalent mining height is proposed based on theoretical analysis of rock pressure and ground subsidence. The upper limits of the rock pressure and ground subsidence can be estimated in backfilling mining using this concept along with traditional engineering formulae.

采空区下孤岛工作面矿压显现规律研究

以顾北煤矿1232(1)采空区下孤岛工作面地质条件为背景,采用FLAC3D数值模拟软件对比分析了采空区下孤岛工作面矿压显现规律与一般孤岛工作面的差异。研究表明:受上覆煤层采动影响,会引起下方孤岛面煤体卸压,所以采空区下孤岛面相对于实体煤下孤岛面矿压显现不显著。通过现场实测分析,数值模拟所得的矿压显现规律与实测结果相吻合,说明利用数值模拟的方法确定采空区下孤岛面矿压显现是可行的。

采空区下综采工作面开切眼一次成巷支护技术

为实现采空区下戊9.10-19070开切眼一次成巷支护,采用弹塑性力学理论分析了开切眼顶板稳定性,通过模糊综合评判得出其围岩类别,从围岩应力、围岩强度、巷道支护及设备选型方面探讨了戊9.10-19070开切眼一次支护可行性,根据工程类比法确定了开切眼一次成巷支护方案,并对围岩变形进行了监测。研究结果表明:戊9.10-19070开切眼上覆戊8-19070采空区底板最大破坏深度为8 m,其煤层以上10 m顶板为完整岩层,开切眼围岩属Ⅲ类中等稳定,支护形式为锚网索;经分析确定戊9.10-19070开切眼一次支护是可行的,并确定了一次成巷支护具体支护参数和施工顺序;一次成巷支护后,开切眼顶板最大离层量21 mm,顶底板最大移近量170 mm,两帮最大移近量80 mm,实现了采空区下开切眼一次成巷支护,经济效益和社会效益明显。