海底隧道风化裂隙岩体注浆扩散加固机理研究

Grouting diffusion and reinforcement mechanism and stability evaluation of weathering fissure rockmass is a crucial scientific problem needing to be solved during construction of subsea tunnels in our country. This project is planning to use a series of methods, including theoretical analysis, numerical simulation, laboratory test, model test and field test, to study the scientific problems. Firstly, the fracture parameters and spatial distribution law are studied, a model of fracture combination characteristic is proposed. The mineral composition, particle size distribution and filling degree of fracture filling medium are tested, and the grading and quantitative characterization method of filling medium is established. Then, the time-dependent behavior and setting time of slurry under the influence of seawater ion are studied, the slurry diffusion law in the fracture is analyzed. The interface characteristics of rock-slurry is determined, and then the mechanism of the effect of crack microstructure on the mechanical properties of macro-reinforcement is revealed. Finally, the mechanism of shear seepage weakening of reinforcement under excavation disturbance and seawater erosion is determined, and the quantification evaluation method of grouting reinforcement is proposed. Field test is carried out to test and improve the research results. Research result is of great theoretical and practical value for preventing and controlling water inrush disaster of subsea tunnel and ensuring the safety of engineering construction and operation.

海底隧道风化裂隙岩体注浆扩散加固机理及稳定性评价方法是我国公共交通建设过程中亟需解决的科学问题。本项目拟采用理论分析、数值模拟、室内试验、模型试验及现场试验相结合的方法开展研究。首先，分析裂隙参数及空间展布规律，建立裂隙组合特征模型，开展裂隙充填介质矿物成分、颗粒级配、充填程度等测试分析，建立充填介质分级定量表征方法；其次，研究海水离子对浆液粘度时变性、凝结时间的影响规律，分析海水条件下风化裂隙岩体浆液扩散规律；确定裂隙岩-浆胶结界面特征，进而揭示裂隙微观结构对宏观加固体力学性能的作用机制；最后，确定开挖扰动及海水侵蚀作用下加固体剪切渗流弱化机制，提出裂隙注浆加固体稳定性的量化评价方法，通过现场试验验证完善研究成果。研究成果对于海底隧道突水灾害防控、保障工程建设及运营安全具有重大的理论和实践价值。

随着经济社会的快速发展和城镇化水平的不断提升，我国东部沿海地区对城际、省际、跨区域交通建设提出了巨大需求。相较于桥梁与航运运输方式，海底隧道具备全天候运营、占地面积小、不影响航运等优点。因此，建设各种各样的跨海通道已成为必然趋势。当前，海底隧道建设过程中经常遭遇断层破碎带、风化槽裂隙地层等不良地质，极易引发塌方失稳、突水突泥等灾害。相较于断层破碎带引发的突水突泥灾害，海底隧道修建过程中风化裂隙岩体往往不易引起足够重视，但受开挖扰动、海水压力影响，风化裂隙岩体往往产生渗流失稳，并最终引发突水灾害。注浆作为解决不良地质段地质灾害的常用方法，但目前少有针对风化裂隙岩体注浆扩散加固机理及稳定性评价方法以及防控方法的研究。本项目拟采用理论分析、数值模拟、室内试验、模型试验及现场试验相结合的方法对上述问题展开研究。首先，分析裂隙参数及空间展布规律，建立裂隙组合特征模型，开展裂隙充填介质矿物成分、颗粒级配、充填程度等测试分析，建立充填介质分级定量表征方法；其次，研究海水离子对浆液粘度时变性、凝结时间的影响规律，分析海水条件下风化裂隙岩体浆液扩散规律；确定裂隙岩-浆胶结界面特征，进而揭示裂隙微观结构对宏观加固体力学性能的作用机制；最后，确定开挖扰动及海水侵蚀作用下加固体剪切渗流弱化机制，提出裂隙注浆加固体稳定性的量化评价方法，通过现场试验验证完善研究成果。研究成果对于海底隧道突水灾害防控、保障工程建设及运营安全具有重大的理论和实践价值。