基于流固耦合的深部煤层采动底板突水机理研究

Study on water-inrush mechanism of mining floor of deep coal seam in mine shaft based on fluid-solid coupling

为了研究煤层深部开采底板采动破坏特征及与浅部开采的差异及底板突水机理,以淮北矿区下组煤底板为研究对象,建立了3种不同采深的底板突水模型。基于FISH语言对FLAC3D软件进行二次开发,对流固耦合条件下不同深度煤层采动底板破坏特征进行了综合分析与对比。研究结果表明:深部条件下煤层采动底板破坏形态与浅部明显不同,深部高地应力及高承压水耦合作用下,含水层顶部发育原位张裂带,且在采动影响下,会进一步出现递进导升现象,而浅部开采时无此现象;当采动破坏带与深部递进导升带沟通时,发生底板突水事故,揭示了矿井深部煤层底板原位张裂隙产生—与承压含水层导通—原位导升带发育—采动破坏带与递进导升带沟通这一突水机理。

In order to research the damage characteristics and water-inrush mechanism of mining induceel floor in the deep mine and the difference between in deep and shallow area,the floor of lower group coal in Huaibei Mining Area was set as study object,and three floor models of different mining depths were established. FLAC3 Dhas been developed on the basis of FISH language and the damage characteristics in mining of floor of different depths under fluid-solid coupling were analyzed and compared comprehensively. The study results showed that the damage form of floor in deep area after mining was quite different from the one in shallow area. In-situ tensile fracture developed on the roof of aquifer under coupling of high crustal stress and confined water of high pressure in deep area. Progressive intrusion would happen under the influence of mining,while there was no such phenomenon in the shallow mining. Water inrush disaster could happen while the damage zone caused by mining connected with the progressive zone. The results show the damage characteristics of mining of floor in deep area and the mechanism of water-inrush that can be concluded as follows： in-situ tensile fracture developed fractures connected with the progressive zone,in-situ progressive zone developing,the damage zone caused by mining connected with the progressive zone.