裂隙充填物对围岩形变效应的数值分析

Numerical Simulation of Hydraulic Effect of Fracture Fillings on Deformation of Surrounding Rocks

为了探讨充填物的水力效应对裂隙变形的影响,以大冶铁矿井下调查为基础,基于岩体力学参数及原岩应力测试成果,采用三维有限元方法模拟了裂隙进水前、仅垂直裂隙进水及垂直裂隙和水平裂隙均进水3种情况下,裂隙充填物对围岩变形的影响.研究结果表明,自然状态下,充填裂隙附近围岩的应力降低较小;单一垂直充填裂隙进水,只会引起巷道走向方向上围岩应力的重新分布,对顶底板不会产生较大的影响;而垂直裂隙与水平裂隙的相互贯通是引起充填裂隙带产生大面积垮塌的主要原因.

In order to discuss the hydraulic effect of fillings on the deformation of fractures, finite element analysis was used to simulate the effect of fracture fillings on surrounding rock deformation under three states： the normal state of filled fracture, the state of only vertical fracture filled with water, and the state of both the vertical and horizontal fractures filled with water. The investigation into the geological setting of Daye Iron Mine, the testing results of rock mass, and initial stress of surrounding rock shows that, in normal state, the stress decreases a little for surrounding rock near the filled fractures. That the water filling into vertical fractures can only cause redistribution of stress of surrounding rock along strike of the tunnel, without any effect on roof and floor. But the mutual penetration between vertical and horizontal fractures is the major reason for wide range of collapse in filled fracture zones.