近陷落柱深埋巷道掘进突水灾变演化规律研究

Study on Evolution Law of Water Inrush Disaster in Deep Roadway Excavation Near Collapse Column

为研究深埋巷道掘进侧穿通过陷落柱时的突水灾变规律,以东庞井田2903工作面回风顺槽为研究对象,基于围岩应力-损伤-渗流耦合模型,采用FLAC3D软件研究了巷道掘进过程中陷落柱周边岩体位移、塑性区、渗透率以及涌水量的时空演化特征。在此基础上分析了不同陷落柱水压、陷落柱与巷道最小净距对陷落柱突水规律的影响。研究结果表明:近陷落柱深埋巷道侧穿通过陷落柱时,其近陷落柱帮以及顶底板位移会往陷落柱方向大幅扩展,最终导致陷落柱与巷道之间岩体发生整体滑移失稳,引发严重的突水灾害事故;近陷落柱深埋巷道掘进过程中,其突水特征具有滞后性、突发性以及大体量性;陷落柱水压对邻近巷道岩体塑性区扩展与导水裂隙通道形成具有明显的诱导作用,当水压超过临界值时,陷落柱与巷道之间的岩体将被冲出,其涌水量呈现跃迁式增长;陷落柱与巷道最小净距越小,陷落柱向巷道内发生突水的时间节点就越靠前,其涌水量也相对越大。

In order to study the law of water inrush disaster when the excavation side of deep roadway passes through the collapse column,the return airway of 2903 working face in Dongpang mine field is taken as the research object.Based on the stress-damage-seepage coupling model of surrounding rock,FLAC3D software was used to study the spatial and temporal evolution characteristics of rock mass displacement,plastic zone,permeability and water inflow around the collapse column during roadway excavation.On this basis,the influence of different water pressure of collapse column and the minimum net distance between collapse column and roadway on the water inrush law of collapse column was analyzed.The results show that when the deep buried roadway near the collapse column passes through the collapse column,the displacement of the near collapse column side and the roof and floor will expand greatly in the direction of the collapse column,which will eventually lead to the overall slip instability of the rock mass between the collapse column and the roadway,causing serious water inrush disasters.During the excavation process of the deep buried roadway near the collapse column,the water inrush characteristics are lagging,sudden and large.The water pressure of the collapse column has an obvious induction effect on the expansion of the plastic zone and the formation of the water-conducting fracture channel of the adjacent roadway rock mass.When the water pressure exceeds the critical value,the rock mass between the collapse column and the roadway will be washed out,and the water inflow shows a transitional growth.The smaller the minimum net distance between the collapse column and the roadway,the earlier the time node of water inrush from the collapse column to the roadway is,and the larger the water inflow is.