中文摘要：

突水与突泥是隧洞施工过程中常遇的重要工程灾害之一,本文利用离散元法,采用颗粒流PFC3D软件,结合流体动力学数值模拟的有限体积法,建立了由裂隙岩体及断层组成的围岩隧洞突、涌水三维数值模型,模拟隧洞突水、突泥的全过程;探讨了集中水源（断层）水压力、岩体裂隙性状等对隧洞突水、突泥的影响。据此提出了工程突水、突泥预防中两个重要的概念：突水临界水压力和前方临界突水距离。并提出了隧洞突水、突泥的发生机理,认为突水发生的前提是存在集中的高压水源。水源压力的大小、开挖面至集中水源的距离、岩体强度、岩体裂隙性状是影响突水的主要因素。

英文摘要：

Water burst is one of the main disasters in the process of tunnel excavation.The software of PFC3D based Discrete Element Method（DEM） was A 3D numerical model including fractured rock and fault has been established.The whole process of water burst and collapsing due to tunnel excavation was simulated by using DEM and Computational Fluid Dynamics（CFD）.The influence of fault＇s hydraulic pressure and fracture condition in rock on the quantity of water burst or collapsing was discussed.Two new conceptions—critical hydraulic pressure of water source and critical distance between excavation surface and water source were proposed.Finally,the mechanism of water burst and collapsing are concluded,i.e.the existence of water source with high water pressure is necessary for the occurrence of water burst,and pressure value of water source,distance between excavation surface and water source,and the mechanical property of rock and the fracture condition in rock mass are the main influencing factors.