TBM掘进扰动下岩体水力破裂及突水致灾机理研究

The technique of Tunnel Boring Machine (TBM) is gaining its popularity in an unprecedented speed for people’s attention in the construction of deep tunnel. Although extensive studies of water inrush mechanism in tunnelling excavation using Drilling-Blasting Method have been done, the relevant studies on the mechanism of hydraulic fracturing in rock mass and water inrush in terms of TBM are still rare. Hence, this project aims to bring more scientific insights into the mechanism of hydraulic fracturing in rock mass and water inrush induced by TBM construction. First and foremost, the mode and evolution mechanism of hydraulic fracturing in rock mass under the driving disturbance of TBM would be revealed. The constitutive relation and constitutive model of hydraulic fracturing in rock mass would be developed, and calibration method between microscopic parameters and mechanical parameters of rock mass would be proposed. The DEM (Discrete Element Method)-CFD (Computational Fluid Dynamics) coupling platform will then be developed to simulate the process of the hydraulic fracturing in rock mass under laboratory scale. Through the model test and the numerical simulation of water inrush induced by TBM construction, the progressive failure process and mechanism of water inrush will be revealed. Also, the digitization and visualization of the water inrush process would be achieved. The research results will help with providing engineering guidance and decision support for the prevention and the control of water inrush induced by TBM construction, which has great significance for reducing and controlling the occurrence of water inrush.

TBM技术正以其无可比拟的速度优势逐渐成为深长隧洞施工的首选，众多学者针对钻爆法隧道突水灾害的致灾机理开展了大量研究工作，但对于TBM掘进扰动下岩体水力破裂和突水致灾机理的相关研究较少，缺乏科学、系统的研究成果。因此，本项目围绕TBM掘进扰动作用下岩体水力破裂和突水致灾机理，开展系统研究工作。通过本项目的研究，旨在揭示TBM掘进扰动下岩体水力破裂模式与演化机制，建立岩体的水力破裂本构关系和数值计算本构模型，提出细观参数与岩体力学参数间的标定方法，采用离散单元法和计算流体力学耦合的方案，实现实验室尺度下岩体水力破裂过程的模拟。通过TBM掘进诱发突水模型试验和数值模拟研究，揭示TBM掘进诱发突水的岩体渐进破坏过程及其致灾机理，实现突水过程的数字化和可视化，为突水灾害防控提供工程指导和决策支持。项目研究成果将为TBM隧道突水灾害防治提供理论基础，对减少和控制突水灾害的发生，具有十分重要的意义。

深长隧道施工越来越倾向于优先采纳TBM施工方法，主要优势在于提高施工效率、缩短工期。 然而，TBM穿越复杂地质条件时仍然面临突水突泥等地质灾害，极易导致TBM卡机、损坏等重大事故。因此，本项目围绕TBM掘进扰动作用下岩体水力破裂和突水致灾机理，采用调研分析、室内试验、数值模拟、模型试验等综合研究方法开展了系统研究工作。分析了钻爆法与TBM施工对围岩应力场分布特征规律，基于自主研制的“拉-压-剪”全能试验机和高压注水装置，开展常规岩体水力压裂与逐级卸荷下岩体水力压裂试验，揭示了卸荷速率和主应力差对岩体破裂压力和水力裂缝扩展形态的影响，从试验角度验证了TBM与钻爆法施工下岩体破裂区别；建立了岩体水力破裂数值计算本构模型，提出了细观参数与岩体力学参数间的标定方法，实现实验室尺度下岩体水力破裂过程的模拟,研究了不同水平地应力差、不同注水排量以及初始裂缝对裂纹扩展及孔内压力的影响；自主研发了小型简易TBM掘进开挖装置，通过TBM掘进诱发突水模型试验和数值模拟研究，揭示了TBM掘进诱发突水的岩体渐进破坏过程及其致灾机理，为突水灾害防控提供工程指导和决策支持。该项目研究成果在交通工程与水利水电工程等领域方面具有较大的应用前景，尤其是对于深埋长大隧道的TBM施工及设计提供试验依据和理论基础，具有重要的科学意义。对于减少和控制TBM掘进扰动导致的突水灾害的发生，保障工程及人员的安全等，具有重要的现实意义。