摘要
结合路基粉土在循环荷载下的动力特性试验,提出动回弹模量与累积变形的预估模型.通过动力有限元分析并与现场实测相比较,研究在列车荷载作用下铁路粉土路基的动应力响应.建立列车在运行条件下铁路粉土路基长期沉降的计算方法,探讨列车速度、轴重、轴载次数以及道床、路基参数等对路基长期沉降的影响.研究表明:当线路平顺性较差且路基压实系数不高时,铁路粉土路基的长期沉降随列车速度提高线性增大,随轴载次数增加先快后慢增长,且列车轴重越大或路基压实系数越低,沉降速率越快;当粉土路基压实系数较低时,适当增加道床厚度或提高路基压实系数均能显著减小路基长期沉降;在列车动载下铁路粉土路基的长期沉降存在一个"临界影响深度",路基压实系数越低,影响深度越大.
The prediction models of resilient modulus and accumulative deformation were obtained based on the triaxial test results of silt subgrade soil under repeated loads. The dynamic stress of railroad silt subgrade induced by train loading was analyzed through dynamic finite element analysis and field measurements. A computational procedure of long-term settlement of railroad silt subgrade was proposed. The influences of train speed, axle load, number of load repetitions, and parameters of ballast and subgrade on the long-term settlement of subgrade were analyzed. If the rail track is seriously irregular and the subgrade compacting factor is very low, the long-term settlement of railroad silt subgrade linearly increases with the train speed, and gradually grows with the number of load repetitions, especially in conditions of high axle load and low subgrade compacting factor. At low compacting factor, the settlement of silt subgrade significantly reduces with increasing ballast thickness or subgrade compacting factor. Moreover, there is a threshold influence depth of the long-term settlement of railroad silt subgrade subjected to train loading, and the lower subgrade compacting factor, the deeper influence depth.
出处
《浙江大学学报（工学版）》
EI
CAS
CSCD
北大核心
2010年第10期1912-1918,共7页
Journal of Zhejiang University：Engineering Science
基金
中国博士后科学基金资助项目(20090460660)
上海市博士后科研计划资助项目(10R21416300)
江苏省自然科学基金资助项目(BK2009466)
关键词
列车荷载
粉土路基
长期沉降
动力有限元
train loading
silt subgrade
long-term settlement
dynamic finite element analysis
