隧道施工突水突泥形成过程及受断层倾角影响研究

Study of the Formation Process of Mud and Water Bursts During Tunnel Construction and the Influence of Fault Dip Angles

隧道穿越富水断层区段极易发生突水突泥现象,是隧道施工中面临的一类严重的工程灾害问题。为了探究突水突泥形成过程和其受断层倾角的影响,避免隧道施工穿越富水断层区段时发生严重的突水突泥工程灾害,文章利用离散元方法,通过颗粒体与流体耦合,模拟了富水断层在不同倾角时,隧道开挖所引起的突水突泥全过程。模拟过程中对隧道周围岩体的裂隙发育、隧道内的突水量和突泥量进行追踪和统计,分析了突水突泥通道的形成过程,揭示了断层倾角对隧道突水突泥的影响。结果表明,富水断层倾角越小,隧道与断层的垂直距离越小,越易发生突水突泥破坏,且突水突泥越易集中在掌子面底部位置。该研究结果可为富水断层区域隧道开挖的方案设计及突水突泥事故的预测和防治提供参考。

Mud and water bursts are common phenomena when tunnels pass through water-rich fault zones and are serious disasters eneountered during tunnel construction. In order to explore the formation proeess of mud and water bursts in tunnels and the influence of fault dip angles on the formation process in order to avoid serious engineering disasters, the processes of mud and water bursts induced by tunnelling in water-rieh fault zones with different dip angels were simulated by Discrete Element Method （DEM） based on coupling the particle and fluid. In the simulation proeess, the development of fractures in surrounding rocks and the amounts of inrushing mud and water were traced and recorded, the formation processes of the mud- and water-bursting channels were analyzed, and the influence of fault dip angles on mud and water bursts was revealed. The study shows that the smaller the fault dip angles, the shorter the vertical distances between the fault and tunnel, and the more likely that mud and water bursts will occur and eoncentrate at the bottom of the working face. The study results provide a referenee for the design of tunnel excavations in water-rich fault zones as well as for the forecast and prevention of mud and water bursts.