混凝土与水泥乳化沥青砂浆界面广泛存在于我国高速铁路纵连板式无砟轨道结构中，但使用过程中部分界面的脱黏及开裂导致轨道板上拱，影响高速列车的安全运营。本课题聚焦于该类无砟轨道结构界面在温度荷载与列车反复作用下的疲劳性能与损伤机制，开展以下研究：基于轨道结构温度实测数据，编制考虑温度荷载与列车活载组合效应的典型载荷谱；在此基础上，开展界面疲劳断裂试验，利用数字图像相关技术，研究界面疲劳应力演化规律和界面破坏形态，建立界面剪切和拉伸粘结力的强度退化模型；基于细观力学理论，构建混凝土-砂浆界面多尺度计算模型，实现界面疲劳损伤和破坏全过程的虚拟仿真，明确温度荷载与列车反复作用对混凝土与砂浆界面疲劳开裂行为的影响；基于界面裂纹萌生与扩展机制，建立界面疲劳寿命预测模型，对界面在反复荷载作用下的安全性进行合理评估。本课题的研究成果可为纵连板式无砟轨道界面裂缝的维修加固与抗疲劳设计提供重要参考。

The bonding interface of concrete and cement emulsified asphalt mortar has been widely used in the continuous slab ballastless track in high-speed railway in China. However, the debonding and crack of some interfaces cause the upward deformation of slab track, which directly affects the safe operation of high-speed train. This research project focuses on the fatigue performance and damage mechanism of the slab track’s interface which is under the repeated actions of temperature load and train. The research contents include: Based on the measured data of the track structure’s temperature, the load spectrums considering the coupling effect of temperature and live load are established. On this basis, the interface fatigue fracture tests are carried out. The evolution law of interface fatigue stress as well as the interface failure pattern are obtained by the digital image correlation technology. Then, the degradation model of interface shear and tensile cohesive strength can be established. Afterwards, the multi-scale numerical model of concrete to mortar interface which is used to realize the virtual simulation of the interface’s damage and failure processes should be established. And the influence of repeated actions of temperature load and train on the interfacial crack behaviour can be clarified. Eventually, based on the mechanism of interfacial crack produce and propagation, the interface fatigue life prediction model is established. Thus, the interface safety under repeated actions can be reasonably estimated. The research results can provide an important reference for the reinforcement and fatigue resistance design of continuous slab ballastless track's interface.