【摘要】 针对高速铁路双块式无砟轨道道床板-支承层层间界面损伤及疲劳破坏问题,制作了混凝土复合试件并开展界面疲劳开裂试验,研究了循环荷载下层间界面的力学性能演变规律。基于试验得到了界面张力-位移关系以及界面疲劳S-N曲线,并与相关文献对比验证了结果的合理性;同时,探明了界面张开位移、速率与幅值增长率随荷载循环次数的演变规律。结果表明:界面张开位移呈现出快速增长、稳定与不稳定增长三个阶段,张开位移幅值约为5～15μm时混凝土界面出现分离现象;界面疲劳破坏历程以第二阶段为主,可通过监测界面张开位移幅值预估界面疲劳剩余寿命,对无砟轨道安全服役提供参考。更多还原

【Abstract】 To address the interface fatigue damage of double-block ballastless track in high-speed railways, by making the composite specimens of the slab-supporting layer concrete(SSC) and designing the test program of the interface fatigue cracking, the mechanical performance evolution law of the adhesive interface of the SSC was investigated under cyclic load. Based on the tests, the interfacial tension force-displacement relationship and the S-N interfacial fatigue curve were acquired, and its rationality of the results was validated by comparing with relevant references. Meanwhile, the evolution law of the opening displacement, velocity and the growth rate of the opening amplitude at the interface varying with the load cycles were revealed. The results show that the development of the interface opening displacement presents a three-stage evolution rule including rapid growth, stable growth and unstable growth. The interface opening amplitude is 5-15 μm when the concrete interface is separated. The stable growth stage is the main stage during the fatigue deformation process, the proposed relationship at this stage between the load cycles and the opening velocity or the growth rate of the opening amplitude at the interface can be adopted to predict the entire evolution law and to predict the interface fatigue life.更多还原