摘要
在地铁工程建设中,由于城市规划建设、节约用地或地形条件的限制,地铁道岔有时需要铺设到大坡道地段上,当道岔铺设在坡道上时会受到列车频繁的制启动作用导致轨道纵向力增加,使得道岔钢轨产生不均匀爬行现象从而影响道岔的正常服役使用。为真实地研究在循环荷载作用下大坡度道岔的纵向受力变形特征,开展大坡度地铁道岔足尺模型试验,研究循环荷载作用下大坡度道岔钢轨的变形规律及考虑车轮轴重值、扣件弹条失效个数等不同因素对大坡度道岔纵向变形的影响。研究结果表明:在单次加载-卸载过程中,钢轨的位移随着荷载增大而增加的越来越快,卸载后迅速回落并产生0.061 mm的残余位移;在循环荷载作用下,加载时的钢轨最大纵向位移值与卸载后的残余位移值均随荷载循环作用次数增加而呈现先快速增大后缓慢增长,最后逐渐趋于稳定的趋势,200次作用后残余位移值基本稳定在0.15 mm;车轮轴重值越大,荷载循环作用下加载时的钢轨纵向位移及卸载后的钢轨纵向残余位移越小;扣件失效个数越多对荷载循环作用下钢轨纵向位移及钢轨纵向残余位移影响越大。
In metro engineering construction,due to the urban planning and construction,economical use of land or the limitation of terrain conditions,metro rail sometimes needs to be laid on the large slope area.When the rail is laid on the ramp,the rail longitudinal force increases on account of frequent train startup and break,resulting in uneven crawling of the switch rail and affecting normal service of the switch.To study the longitudinal stress deformation characteristics of the large lope switch under cyclic loading,a full scale model test on large slope metro switch is conducted to study the deformation law of switch rail under cyclic loading,and the influences of different factors such as the wheel axle load value and the fastener failure on the large slope switch longitudinal deformation.The results show that in the process of single loading-unloading,the rail displacement increases faster and faster with the increase of the load,and rapidly falls back after unloading and produces a residual displacement of 0.061 mm;under cyclic loading,the maximum longitudinal displacement of the rail during loading and the residual displacement after unloading both increase rapidly at first,then slowly tend to stabilize with the increase of cyclic loading times;after 200 times of cyclic loading,the residual displacement is basically stable at 0.15 mm;the larger the wheel axle weight value,the smaller the longitudinal displacement of rail under cyclic loading and the longitudinal residual displacement of rail after unloading;the more the number of fastener failure,the greater the influence of rail longitudinal displacement and rail longitudinal residual displacement under cyclic loading.
作者
周剑
丁玉宝
侯泰成
马前涛
李浩然
李智恒
陈嵘
徐井芒
ZHOU Jian;DING Yubao;HOU Taicheng;MA Qiantao;LI Haoran;LI Zhiheng;CHEN Rong;XU Jingmang(China Railway Construction South China Construction Co.,Ltd.,Guangzhou 511458,China;MOE Key Laboratory of High-Speed Railway Engineering,Southwest Jiaotong University,Chengdu 610031,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)
出处
《铁道标准设计》
北大核心
2023年第9期62-68,共7页
Railway Standard Design
基金
四川省杰出青年科技人才项目(2020JDJQ0033)
中铁建华南建设有限公司科技开发课题(20-B-05)。
关键词
地铁
大坡度道岔
足尺模型试验
循环荷载
钢轨爬行
扣件失效
subway
large slope turnout
full-size model test
cyclic loading
rail crawling
fastener failure
