冲击地压应力流思想及其控制理论初探

Preliminary theoretical study on stress flow thought for coal bump and its control

采动应力在时间和空间上动态演化过程称为煤矿开采的应力流。为了研究煤矿应力流动特征,分析矿区开采过程中的煤岩结构特征,理论求解缓倾斜单一煤层相邻工作面开采后的应力流动方向和应力流发生的临界条件。基于义马矿区实际条件,建立7种地质因素和开采因素影响下的邻面开采数值模型,研究不同因素下的应力流主控条件,得到相邻工作面布置原则及最优参数。结果表明:多采场区域覆岩结构单元包括两近距离工作面范围内的采空区、中间煤柱和未垮落岩层;缓倾斜单一煤层开采时,先采工作面开采后应力流向中间煤柱,后采工作面开采后应力流向先采工作面或中间煤柱;义马矿区相邻工作面布置原则应满足:工作面优先布置在煤厚和巨厚砾岩厚度较小的区域,增大邻面煤柱宽度,减小工作面的倾向长度,增大邻面的垂直错距,增大先采面的先采长度,后采面朝着靠近先采面采空区方向回采。研究结果可为巨厚砾岩控制下的冲击地压发生机理和防治提供理论基础。

The dynamic change of mining stress in time and space is called stress flow in coal mining.In order to study the characteristics of coal mine stress flow,structural characteristics of coal and rock was analyzed,and the direction and the critical conditions of stress flow after mining in adjacent working faces in gently-inclined single coal seam were theoretically solved.Based on actual conditions of Yima mining area,numerical models of adjacent mining under influence of 7 geological factors and mining factors were established.Main conditions of stress flow under different factors were studied,and layout principle and optimal parameters of adjacent working faces were obtained.The results have shown that overburden structure unit of multi faces includes goafs,middle coal pillars,and non-caving strata within two close-distance working faces.During the mining of single gently-inclined seams,stress flows to the middle coal pillar after former face is mined;after the later face is mined,stress flows to former face or the middle coal pillar.The layout principle of adjacent working faces in Yima mining area should satisfy the following requirements:the working face should be preferentially arranged in the area with coal and huge thick conglomerates of small thickness,the width of coal pillars adjacent to the working face should be increased,the inclination length of the working face should be reduced,the vertical offset of two adjacent faces should be increased,the mining length of the former face should be increased,and the later mining face should be mined towards the goaf of the former face.The findings provide a theoretical basis for the mechanism and prevention of coal bump under control of huge thick conglomerate.