摘要
新型钢管混凝土(CFT)双块式轨枕克服了桁架钢筋双块式轨枕存在的生产制造复杂、存放易锈蚀、运营阶段易开裂等问题,可广泛应用于高速铁路和城市轨道交通无砟轨道结构。为检验CFT双块式轨枕无砟轨道结构的疲劳性能,采用11根预制CFT双块式轨枕现浇制作足尺无砟轨道结构节段模型,开展橡胶隔振垫式减振轨道和现浇整体式轨道节段的疲劳试验,揭示其疲劳损伤特性,分析典型疲劳加载循环次数后静载作用下轨道结构应变和变形分布及其演化规律。研究结果表明:1.5倍静轴重的疲劳荷载累计作用500万次后,减振节段及整浇节段CFT双块式轨枕无砟轨道结构混凝土均未出现肉眼可见的裂缝,轨枕与现浇道床整体工作性能良好,疲劳性能满足规范要求;停机开展静载试验过程中轨道结构各测点混凝土横向应变值随荷载增大而近似线性增大,最大拉压应变值均远小于混凝土的极限应变值,工作状态良好;轨道整浇节段道床板中处于整体受拉的状态,可见设置层间连接钢筋实现了道床与底座的共同工作;疲劳试验过程中轨道结构测点竖向位移值总体随着静载的增大而逐渐增大,位移量级较小,满足规范要求,减振轨道节段竖向位移值及其变化率大于整浇轨道节段。研究结果可供类似研究及钢管混凝土双块式轨枕无砟轨道结构工程应用参考。
The new concrete filled steel tube(CFT)connected double-block sleeper overcomes the problems existing in the truss reinforcement double-block sleeper,such as complex production and manufacturing,easy corrosion in storage,and easy cracking in operation,which can be widely used in high-speed railway and urban rail transit ballastless track structure.In order to test the fatigue performance of CFT double-block sleeper ballastless track structure,a full scale ballastless track structure segmental model was casted in situ using eleven prefabricated CFT double-block sleepers.The fatigue tests were carried out on the damping track with rubber vibration isolation pad and monolithic cast in situ track segments.The fatigue damage characteristics were revealed for these two kinds of track structure.The distribution and evolution of strain and deformation were analyzed for track structure subjected to static load after typical fatigue loading cycles.The results show that after 5 million times of fatigue loading at the level of 1.5 times the static axle load,there is no visible cracks in the concrete structure of ballastless track with CFT double-block sleepers in the damping segment and the cast in situ segment.The overall working performance of the sleepers and the cast-in-place track bed is good,and the fatigue performance meets the specification requirements.During the static loading test,the transverse strain value of concrete at each measuring point of the track structure increases approximately linearly with the increase of load,and the maximum tensile and compressive strain value is far less than the corresponding limit strain value of concrete,which is in good working condition.The middle layer of track bed slab of the cast in situ segment is in the state of overall tension,and it can be seen that the joint working of the track bed and the base plate is realized by setting the interlayer connecting reinforcement.During the fatigue test,the vertical displacement value of the track structure at measuring point graduall
作者
刘晓春
陈佳琦
罗延亮
朱志辉
李启航
郑纬奇
LIU Xiaochun;CHEN Jiaqi;LUO Yanliang;ZHU Zhihui;LI Qihang;ZHENG Weiqi(National Engineering Research Center of High-speed Railway Construction Technology,Central South University,Changsha 410075,China;School of Civil Engineering,Central South University,Changsha 410075,China;China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan 430063,China)
出处
《铁道科学与工程学报》
EI
CAS
CSCD
北大核心
2024年第1期106-115,共10页
Journal of Railway Science and Engineering
基金
国家重点研发计划项目(2022YFB2603301)。
关键词
无砟轨道
双块式轨枕
钢管混凝土
减振轨道
疲劳试验
静载性能
ballastless track
double-block sleeper
concrete filled steel tube
damping track
fatigue test
static performance
