大倾角大采高综采面倾向长度尺度效应分析

Analysis on the scale effect in the fully mechanized mining panel width with large mining height and dip angle

以大倾角大采高综采为背景,通过理论分析、相似模拟和现场实测,对大倾角大采高综采基于工作面倾向长度尺寸效应导致的围岩灾变机理进行了分析,研究认为大倾角煤层直接顶和基本顶运动的不协调性使得控顶难度加大,工作面直接顶沿倾向可分为充填稳定段、易溃屈段和滑移段结构,相应矿压显现特征则呈现典型的"弱—强—弱"分布,即溃屈段为矿压显现最强烈区域,也是影响矿压显现的主控因素,对于特定赋存条件大倾角煤层,其工作面长度存在"临界尺寸",工作面支护强度的确定除满足直接顶岩层岩法向方向的自重和部分基本顶载荷外,还需满足上部直接顶滑移产生的附加载荷,其中阻止溃屈段顶板的离层是支护强度确定的主要依据。

In terms of fully mechanized mining with large mining height and dip angle,through theoretical analysis,simulation and field measurement,the disaster mechanism of surrounding rock caused by the size effect of working facewidth was analyzed. The study found that the coordination of immediate roof and main roof movement in the large dipangle coal seam increases the difficulty of roof control. The mine pressure behavior characteristic shows a typical＂weak-strong-weak＂ distribution. The working face roof structure along the tendency was divided into sliding sectionand buckling section. The sliding section had the strongest regional strata pressure,and also was the main control factorof mine pressure behavior. According to the occurrence conditions of coal seam with large dip angle,there is a ＂criticalsize＂ in the length of working face. In addition to meeting the weight of direct roof rock orientation and part of the roofload,the support strength must also meet the additional load generated by top slippage. And the prevention of separa-tion at buckling section is the main basis to determine support strength.