深长隧道充填型致灾构造突水机理与灾变演化全过程模拟研究

This project is focused on the water inrush disasters from filling-type geological structures in deep and long tunnels, which is the urgent need engineering of national infrastructure construction. Mechanical mechanism and evolutionary overall process simulation of water inrush will be systematically investigated using literature review, cases study, theory analysis, laboratory experiment, program development and numerical simulation, respectively. The seepage failure of filling medium in geological structures will be studied first to reveal the seepage-stress coupling failure mechanism and the formation process of preferential migration passage, and then a seepage-stress coupling analytical model of the seepage failure of filling medium will be established. Secondly, for the jointed rock masses between geological structures and tunnel face, the initiation, propagation and coalescence of water-filled crack under dynamic disturbance and unloading effect will be studied, and a seepage-stress coupling analytical model also will be established for analysis of crack initiation and propagation. Finally, a FEM-DEM numerical computational model of filling-type geological structures will be established, and a seepage-stress coupling analytical procedure will be developed so that the evolutionary overall process of water inrush from filling-type geological structures can be simulated. A calculation method for determining the minimum safety thickness of preventing water inrush disasters also will be proposed based on numerical analysis. The research achievement will provide fundamental basis for prevention and control of water inrush disasters in tunnels and underground engineering, and will be of important scientific and practical significance for reduction of water inrush disasters, safety guarantee of people’s lives and properties, and protection of ecological environment.

本项目立足于国家基础设施建设亟需的深长隧道工程，围绕充填型致灾构造突水灾害，采用文献查阅、案例调研、理论分析、室内实验、程序开发和数值模拟等方法，系统开展突水机理与灾变演化全过程模拟研究。首先，针对致灾构造内部充填介质的渗透失稳，揭示其渗流-应力耦合失稳机制及优势通道形成过程，建立充填介质渗透失稳的渗流-应力耦合分析模型；其次，针对致灾构造与掌子面之间的防突裂隙岩体，揭示动力扰动与强卸荷作用下含水裂纹的启裂、扩展与贯通机制，建立防突岩体破裂的渗流-应力耦合分析模型；最后，建立充填型致灾构造的有限元-离散元数值计算模型，开发渗流-应力耦合分析程序，实现充填型致灾构造突水灾变演化全过程的模拟分析，并建立防突厚度数值计算方法。项目研究成果将为隧道及地下工程建设中突水灾害的防治提供理论基础，对减少和控制突水灾害的发生、保障人民生命财产安全与保护生态环境，具有十分重要的科学和实践意义。

隧道断层破碎带突涌水给工程安全建设带来了严峻挑战，但由于致灾构造的孕灾模式与灾变机理极为复杂，导致突涌水灾害预测预警与主动防控缺乏理论依据。为此，本项目围绕断层破碎带突涌水灾变机理与演化过程，采用案例调研、理论分析、室内实验、程序开发和数值模拟等综合研究方法，开展了系统深入的研究工作，取得了如下标志性成果：.（1）针对断层破碎带等致灾构造，量化分析了断层附近区域地应力的分布特征及其方位、量值随埋深的变化规律，统计发现了断层泥粒度分布曲线的一重和多重分形特征。.（2）针对断层破碎带突涌水机理，自主研制了渗流-应力-侵蚀耦合失稳突水三维试验装置，通过系列试验揭示了渗透破坏突涌水的“变强度-变渗透性-变粘度”灾变机制及其优势通道形成过程。.（3）针对断层破碎带突涌水演化过程模拟，提出了基于DEM-CFD耦合的突涌水过程分析方法，建立了可描述充填介质强度演化规律的接触模型，提出了基于REV全区域覆盖的FEM-DEM耦合建模方法，实现了断层破碎带突涌水过程的模拟分析。.（4）针对致灾构造与掌子面之间的防突岩体，自主研制了含水裂隙动力损伤性能测试系统，发现了爆破荷载诱发的裂隙水压内升与应变振荡现象，揭示了动力扰动、高水压和高地应力三者联合作用下防突岩体的渗流-应力耦合渐进破裂机制，并基于防突岩体分区新认识：扰动破坏区、渗透破坏区、层裂破坏区，建立了防突最小安全厚度计算方法。.项目成果为隧道及地下工程建设中突涌水灾害的监测预警与主动调控提供了科学依据，对提升我国隧道突涌水灾害防控的核心技术水平、减少和控制突涌水灾害的发生具有十分重要的科学和实践意义。.本项目获省部级技术发明一等奖1项，科技进步一等奖3项、二等奖1项；授权国家发明专利25项、软件著作权12项；发表期刊论文33篇，其中SCI/EI论文32篇，出版专著1部，参编团体标准2项，获省部级工法3项。项目成果在成兰铁路、吉莲高速等隧道突涌水灾害防控中得到应用及推广。