地下铁矿床灰岩顶板突水机理模拟研究

An Analysis of the Mechanism of Water Burst on Limestone Roof of Underground Iron Ore Mining

根据水和岩石间力的传递过程的基本理论,利用SURPAC生成的真实地质模型,运用FLAC3D模拟了真实矿体开挖、填充对顶板稳定性的扰动.结果表明:矿房顶板的拉应力、沉降和塑性深度都随开挖步的进行逐渐增加,在开挖完5层后,拉应力的影响深度为10 m左右;矿房顶板的沉降为9.2 mm;矿房顶板的塑性深度为25 m;最大孔隙水压力随开挖步的进行逐渐减小.此时矿房顶板和注浆灰岩顶板在扰动下的塑性区都还没有贯通,注浆灰岩的隔水性能够得到保证.

According to the basic theory about the transfer process of stress between water and rocks,the real geological model was generated by using SURPAC and simulating the influence on roof stability by real excavation and filling.The results showed： the tensile stress,settlement and plastic depth of roof increase gradually in excavation;after having excavated five layers,the tensile stress was about 10m deep,the settlement of roof 9.2 mm and plastic depth 25 m.The maximum pore water pressure dwindles away along with excavating steps.At this point,the plastic zone of the ore and limestone roofs has not run through in the disturbances and the watertight grouting of the limestone can be guaranteed.