外力作用下错缝拼装盾构隧道粘钢加固结构损伤演化机理研究

It is obviously necessary to take the rational reinforcement to ensure the safety of tunnel lining, as the shield tunnel would exist some serious structure deformation, segment cracks and joint open influenced by the surrounding activities, which decreasing the bearing capacity of the structure. By model tests, numerical simulation and theoretical analysis, the project is aimed to carry out research on the bearing capacity and damage law of the shield tunnel with staggered-jointed and steel-bonded reinforcement structure under different engineering activities. Based on the above work, the key indicators for evaluating the structure safety will be firstly put forward. Then，the failure characteristics of macroscopic deformation and the distribution of the meso-stress for the reinforced structure under different deformation will be discussed, revealing the damage evolution mechanism under external force, to identify the strengthening effect , scope of application and reasonable reinforcement timing for the steel- bonded reinforcement. Finally, we will establish the evaluation model of the ultimate bearing capacity of the section by considering the existing segments damage and the shearing mechanics of the bonding surfaces, and propose the calculation method using the beam-spring model to guide the design of the steel-bonded reinforcement.

由于周边工程活动的影响，地铁盾构隧道结构会出现不同程度变形，甚至引起管片开裂、接缝张开过大等病害，造成服役性能降低，需适时合理加固以确保结构安全。项目拟通过模型试验、数值仿真、理论解析等多种手段，针对堆载、开挖卸载等工程活动对既有盾构隧道错缝拼装结构和粘钢加固后结构的承载性能及损伤规律开展研究，提出结构安全状态评价关键指标；探索既有结构在不同变形状态下采取粘钢加固后的宏观变形破坏特征及细观应力分布发展规律，揭示外力作用下粘钢加固结构的损伤演化机理，探明影响盾构隧道错缝拼装管片粘钢加固效果的关键因素及适用条件、合理加固时机；建立考虑既有管片损伤程度、粘钢-管片粘结面剪切力学行为的截面极限承载力评价模型，提出基于梁-弹簧模型与承载力折减的错缝拼装盾构管片粘钢加固设计计算方法。