摘要
研究目的:双孔限位装配式轨道板因其施工方便、传力路径清晰、稳定性好等特点,在城轨、市域铁路中应用越来越多。为探明市域铁路双孔限位轨道板的受力变形规律,验证轨道结构的承载能力与结构安全性,在试验场地构建非预应力轨道板1∶1实尺试验模型,开展纵、横截面承载能力试验,分析轨道板在静载作用下的力学响应特征。研究结论:(1)在设计荷载范围,轨道板位移随着荷载的增大而增大,试验过程未见明显突变,受力变形状态良好;(2)轨道板在纵截面检验荷载29 kN作用下,最大垂向位移0.896 mm,加载至31 kN开始出现裂纹,40 kN荷载下板中心线贯通裂纹最大值0.17 mm,未超过裂纹设计允许限值,纵截面承载能力满足要求;(3)轨道板在横截面检验荷载28 kN作用下,最大垂向位移2.751 mm,最大应变82.205με,当荷载加载至29 kN时开始出现裂纹,32 kN荷载下裂纹最大宽度0.21 mm,小于设计允许值,横截面承载能力具备充足安全余量;(4)纵、横截面加载过程中下边缘混凝土受压,最大值212.37με,远小于混凝土极限抗压强度限值,受压区工作状态良好;(5)轨道板限位孔四周混凝土应力随荷载增加非线性增长,应变相较于同截面其他测点增幅不超过10με,对轨道板整体强度削弱影响有限,轨道结构安全可靠;(6)本研究成果可为双孔限位板式无砟轨道设计与优化提供试验依据。
Research purposes:Double-hole positioning assembly track slabs are increasingly being used in urban rail and regional railways due to their convenient construction,clear force transmission path,and good stability.To investigate the stress and deformation laws of the double-hole limited-slot track slab of the urban railway,and verify the bearing capacity and structural safety of the track structure,a 1∶1 full-scale experimental track slab model was constructed,and bearing capacity tests were conducted under longitudinal and transverse section loading.Research conclusions:(1)Within the designed load range,the displacement of the track slab increases with the increase of the load,and no significant sudden changes were observed during the test process,indicating a good state of stress and deformation.(2)Under the longitudinal section test load of 29 kN,the maximum vertical displacement of the track slab is 0.896 mm;cracks initiate at 31 kN,and the maximum through-crack width at 40 kN is 0.17 mm,not exceeding the design allowable crack width limit,confirming compliance with longitudinal bearing capacity requirements.(3)Under the transverse section test load of 28 kN,the maximum vertical displacement is 2.751 mm,with a peak strain of 82.205με;cracks initiate at 29 kN,and the maximum crack width at 32 kN is 0.21 mm,below the design allowable limit,indicating sufficient transverse safety margin.(4)During loading,the compressive strain at the lower edge concrete in both sections reaches a maximum of 212.37με,far below the ultimate compressive strength limit of concrete,demonstrating stable performance in the compression zone.(5)The stress of the concrete around the limit hole of the track slab increases nonlinearly with the increase of load,and the strain increases by no more than 10με compared to other measuring points on the same section.This impact on the overall strength weakening of the track slab is limited,and the track structure is safe and reliable.(6)The research outcomes provide experimental evidence for the design and optimization of double-hole positioning ballastless track slabs in regional railways.
作者
李秋义
任西冲
刘杰
周磊
牛亚文
LI Qiuyi;REN Xichong;LIU Jie;ZHOU Lei;NIU Yawen(China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan,Hubei 430063,China;Hubei Key Laboratory for Safe Service of Railway Track,Wuhan,Hubei 430063,China)
出处
《铁道工程学报》
北大核心
2025年第10期22-27,33,共7页
Journal of Railway Engineering Society
基金
湖北省重点研发计划(2023BAB151)
铁四院科技研发课题(CY2025001S,KY2024002S,KY2024021S)。
关键词
市域铁路
轨道板
双孔限位
承载能力
试验测试
regional railway
track slab
double-hole positioning
bearing capacity
experimental testing
