中文摘要：

渗透破坏是隧洞施工过程中面临的一类重要的工程灾害问题,对隧洞渗透破坏机制的研究可应用于隧道施工安全预报。利用颗粒流法在模拟散体及破碎介质方面的优势,结合流体动力学数值模拟的有限体积法,建立由黏结颗粒材料组成岩块的二维数值模型,模拟储水断层中不同的水压力时,隧洞开挖引起的渗透破坏现象,模拟过程可以实时反映开挖过程中微裂隙的扩展及渗透张量的变化。模拟结果表明,颗粒流法模拟岩体渗透破坏过程是可行的,对于隧洞工程开挖具有一定的指导意义。

英文摘要：

Seepage failure is a main disaster in the process of tunnel excavation. The study of seepage failure mechanism is important to predict it and to decrease the probability of this kind of disaster. Taking advantage of discrete element method（DEM） comparing with the traditional numerical modeling on dynamic simulation and characteristic simulation of dispersed particles,the PFC2D based on DEM is adopted to establish the 2D numerical seepage model in which rock is built by bonded particles. The whole process of seepage failure under different hydraulic gradients due to tunnel excavation is simulated by using PFC2D and computational fluid dynamics（CFD）. Propagation of microcracks and permeability changes can be real-time reflected during the excavation. Simulation results show that it is applicable to use particle flow code（PFC） to simulate seepage failure process of rock;and it has certain guiding significance on tunnel excavation.