CRTSⅡ型无砟轨道板疲劳时变可靠度研究  

Time-dependent Fatigue Reliability Evaluation of CRTSⅡBallastless Track Slab

作　　者：童明娜 卢朝辉 赵衍刚 余志武[1] TONG Mingna;LU Zhaohui;ZHAO Yangang;YU Zhiwu(School of Civil Engineering,Central South University,Changsha 410075,China;College of Architecture and Civil Engineering,Beijing University of Technology,Beijing 100022,China;Faculty of Engineering,Kanagawa University,Yokohama 221-8686,Japan)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]北京工业大学建筑工程学院,北京100022 [3]神奈川大学工学部,神奈川横滨221-8686

出　　处：《铁道学报》2020年第10期92-100,共9页Journal of the China Railway Society

基　　金：国家自然科学基金(51820105014,U1934217);中央高校基本科研业务费专项资金(2019zzts286)。

摘　　要：针对CRTSⅡ型轨道板疲劳的潜在失效模式,依据混凝土材料的疲劳性能,建立列车荷载与温度荷载共同作用下CRTSⅡ型轨道板混凝土疲劳功能函数,利用该功能函数开展基于时变可靠度理论的CRTSⅡ型轨道板疲劳时变可靠性研究。时变可靠度、时点可靠度及蒙特卡洛的计算结果对比表明:时点可靠度方法的计算结果与蒙特卡洛结果有较大误差,而本文采用的时变可靠度方法的计算结果与蒙特卡洛方法的输出结果几乎一致,说明本文方法计算精度较高。算例结果表明,在轨道板服役后期,轨道板纵向轨下截面处受拉边缘纤维混凝土容易发生弯拉疲劳开裂,这说明作为主要承受疲劳荷载(循环次数较多、荷载较大)的构件,轨道板的抗疲劳性能需进一步加强。Based on the potential fatigue failure mode of CRTSⅡballastless track slab and fatigue properties of concrete materials,this paper proposed the limit state function of the fatigue strength of track slab under the combined action of train load and temperature load.The limit state function was used to develop a time-dependent reliability analysis method of the fatigue strength of CRTSⅡballastless track slab.The comparison of time-dependent reliability,time-point reliability and Monte Carlo calculation results shows that the calculation results of the time-point reliability method have large errors with the Monte Carlo results,while the calculation results of the time-dependent reliability method used in this paper are almost consistent with the Monte Carlo results,which shows that the time-dependent reliability method is accurate.The results of numerical example demonstrate that the tensile edge of the fiber reinforced concrete in the longitudinal section of track slab is prone to flexural fatigue cracking in the later stage of the service life of the track slab.This indicates that the ballastless track slab,as a main component subjected to fatigue loads with more cycles and repeated loads,needs to be further strengthened in fatigue performance.

关 键 词：CRTSⅡ型轨道板 疲劳 功能函数 时变可靠度 

分 类 号：U213.2[交通运输工程—道路与铁道工程]