隧道衬砌混凝土在使用过程中存在各种损伤，这些损伤会改变其内部微观孔隙结构特征，进而影响其耐久性，而当前从微观层面开展离子侵蚀机制的研究较少。本项目以隧道预制衬砌混凝土结构为对象，聚焦影响最重要的氯盐因素，从混凝土内部微观孔隙结构层面，开展损伤下隧道预制衬砌混凝土氯盐侵蚀机制研究。首先，采用压电阻抗和共振频率技术对试验样本进行损伤量测定，实现损伤状态的定量描述和标定。然后，分别开展三维CT显微成像、X射线渗流模拟、氯盐压力浸泡试验，建立混凝土内孔洞、微裂隙的拓扑结构及损伤状态～损伤量～微观孔隙结构特征的关联关系，揭示其渗透侵蚀机制。再次，基于多孔介质渗透理论，构建可考虑损伤效应、压力水环境及结构受力等因素的氯盐渗透侵蚀理论模型。最后，研究分析不同因素对氯离子侵蚀的影响规律，提出氯盐环境下隧道预制衬砌混凝土抗侵蚀设计方法，服务于工程实际。

Various kinds of damage exist in lining concrete during the whole operation process of tunnel. And this damage will change the micro-pore structure characteristics of concrete, which will degrade its durability. But there are rare studies on the erosive mechanism of corrosive iron developing from the micro-level. In this study, with the consideration of the characteristics of service environment of the tunnel and the most influencing factor of chloride salt focused, the chloride erosion mechanism of tunnel pre-cast lining under damage effect were carried out on the micro-pore structure level. Firstly, the damage amount of samples were measured by piezoelectric impedance and resonant frequency technique, so as to realize the quantitative description an calibration of the their damage states. Then, 3D CT microscopic imaging, seepage simulation by X ray, pressure immersion test were carried out respectively, and the relationship between the hole / the topology of micro-fracture and the damage state ~ amount of damage ~ characteristics of micro-structure was achieved. Consequently, the infiltration erosion of chloride salt of tunnel lining was realized. Thirdly, based on the theory of porous media infiltration, the theoretical model for the infiltration erosion of chloride salt of tunnel pre-cast lining was built, which took into account the damage effect, the water environment and the load characteristics. Finally, the influence of different factors on chloride erosion were studied, and the anti-erosion design method of tunnel pre-cast lining under chloride salt environment was put forward, which can provide reference for actual engineering.