顶板型老空突水模式及导水通道演化机理研究

Study on water inrush mode and evolution mechanism of water channel in roof type goaf

煤矿顶板型老空水害具有很强的冲击力和破坏力,研究老空区水体下覆岩突水通道的演化规律对老空水害防治具有重要意义。以山西某矿8446工作面老空突水事故为例,采用相似模拟与数值模拟方法,探究煤层顶板覆岩结构破坏与水力学之间的耦合规律,揭示了突水通道形态演化机理。研究结果表明:顶板老空突水过程经历了初始渗流阶段、裂隙渗流阶段、管道流突水阶段;初始渗流较应力峰值显现时滞后约3 m,水流沿采动裂隙向下运移平均渗流速度为4.056 m/d,滞后性和渗流速度可作为突水事故关键预警信息;通过流固耦合数值模型的模拟,突水通道位于矩形梯台压实区的四周,与现场实际突水位置基本一致。

The roof type goaf water disaster in coal mine has strong impact and destructive force.It is of great significance to study the evolution law of water inrush channel of overlying strata under goaf water for the prevention and control of goaf water disaster.Taking the goaf water inrush accident of 8446 working face in a mine in Shanxi Province as an example,this paper uses similar simulation and numerical simulation methods to explore the coupling law between the structural failure of coal seam roof overburden and hydraulics,and reveals the morphological evolution mechanism of water inrush channel.The results show that the goaf water inrush process of roof has experienced the initial seepage stage,the fracture seepage stage and the pipeline flow water inrush stage.The initial seepage lags about 3 m behind the peak stress,and the average seepage velocity is 4.056 m/d.The hysteresis and seepage velocity can be used as the key early warning information of water inrush accident.Through the simulation of the fluid-solid coupling numerical model,the water inrush channel is located around the rectangular terrace compaction area,which is basically consistent with the actual water inrush position on site.