开采因素对煤层底板突水影响的数值模拟研究

Numerical simulation study on influence of mining factors on water inrush from coal seam floor

应用FLAC^(3D)数值模拟软件建立了开滦范各庄矿煤岩层地质力学模型,模拟了开采工作面长度、采煤深度以及采煤方法对煤层底板破坏状态,结合突水系数公式,查明了奥灰含水层上开采因素对底板突水影响的定量关系。研究表明,当工作面长度为100~200 m时,底板破坏深度和突水系数变化起伏小;当工作面长度<100 m或>200 m时,底板破坏深度和突水系数随工作面长度增加而变化加剧。随着煤层开采深度由300 m增加至900 m,煤层底板破坏深度和突水系数加大。分层开采法采煤的煤层底板破坏深度和突水系数比一次采全高法低,因而更安全。模拟结果和矿区实际采掘工作面长度及采煤方法相符合。

In this paper,FLAC^(3D)numerical simulation software was used to establish the coal strata geomechanical model of Fangezhuang Mine in Kailuan,simulating the damage state of coal seam floor caused by the length of mining face,mining depth and mining method.Combined with the formula of water inrush coefficient,the quantitative relationship of the influence of mining factors on floor water inrush in Ordovician ash aquifer was found out.The research shows that when the working face length is 100~200 m,the change of floor failure depth and water inrush coefficient is small;when the working face length is<100 m or>200 m,the change of floor failure depth and water inrush coefficient increases with the increase of working face length.As the mining depth of coal seam increases from 300 m to 900 m,the failure depth and water inrush coefficient of coal seam floor increase.The failure depth and water inrush coefficient of coal seam floor are lower in the stratified mining method than in the all-height mining method,so it is safer.The simulation results are consistent with the actual mining face length and mining method.