路基不均匀沉降下无砟轨道受力与变形传递规律及其影响  

Transfer rules and effect of stress and deformation of ballastless track under uneven subgrade settlement

作　　者：向俊[1] 林士财 余翠英[1,2] 袁铖 苏玮 XIANG Jun;LIN Shi-cai;YU Cui-ying;YUAN Cheng;SU Wei(School of Civil Engineering,Central South University,Changsha 410075,Hunan,China;School of Science,East China Jiaotong University,Nanchang 330013,Jiangxi,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]华东交通大学理学院,江西南昌330013

出　　处：《交通运输工程学报》2019年第2期69-81,共13页Journal of Traffic and Transportation Engineering

基　　金：国家自然科学基金项目(U1261113);高等学校博士学科点专项科研基金项目(20100162110022);牵引动力国家重点实验室开放课题(TPL0901;TPL1214);江西省教育厅科技计划项目(GJJ151173;GJJ151175)

摘　　要：针对路基上CRTSⅠ和CRTSⅡ型板式无砟轨道的结构特点,分别建立了相应的有限元模型,研究了路基不均匀沉降作用下不同板式无砟轨道受力与变形的传递规律及其影响。分析结果表明:路基不均匀沉降发生后,上部轨道结构的垂向变形具有一定跟随性,变形与沉降曲线相近但不完全重合;底座板伸缩缝的存在对轨道结构的受力和变形有较大影响,在20 mm/20 m沉降条件下,CRTSⅠ、CRTSⅡ型板的垂向位移分别达沉降幅值的90%和60%,相对CRTSⅠ型板而言,沉降对CRTSⅡ型板的垂向位移影响较小,但后者更易形成较大范围的离缝,离缝长度达6.52 m,为CRTSⅠ型板离缝长度的1.92倍;当沉降幅值位于底座板中心时,离缝主要集中在伸缩缝、沉降端部和沉降中心,但当沉降幅值位于伸缩缝处时,离缝主要集中在伸缩缝两侧和沉降端部;沉降波长或幅值改变时,会导致最大离缝位置出现偏移;在路基不均匀沉降作用下,CRTSⅠ型板的底座板纵向最大拉应力均大于轨道板的纵向最大拉应力,而CRTSⅡ型板的情形则相反;从混凝土强度考虑,CRTSⅠ型板沉降控制标准应以底座板的拉应力控制为主,而CRTSⅡ型板应以轨道板和底座板的拉应力综合控制。The finite element models were established base on the characteristics of CRTSⅠand CRTSⅡslab ballastless track structures on the subgrade.The transfer laws of stress and deformation of different slab ballastless tracks and their effects were analyzed under the role of uneven subgrade settlement.Analysis result indicates that the vertical deformation of the upper track structure deforms accordingly with the subgrade after uneven subgrade settlement occurs.The deformation and settlement curves are similar but not completely coincident.The expansion joints that exist in the base plate have great influence on the stress and deformation of track structure.Under the condition of 20 mm/20 m,the vertical displacements of CRTSⅠand CRTSⅡslabs reach 90%and 60%of settlement amplitude,respectively,the vertical displacement of CRTSⅡslab is less affected by the settlement compared with CRTSⅠslab,but the latter is more likely to form a larger range of seam,and the length of the seam is 6.52 m and 1.92 times the length of the seam of CRTSⅠslab.When the settlement amplitude is located at the center of base plate,the seams are mainly concentrated at the expansion joint,settlement end and settlement center.But when the settlement amplitude is located at the expansion joint,the seams are mainly concentrated on both sides of the expansion joint and settlement end.With the change of settlement wavelength or amplitude,it will cause the maximum position of seam to shift.Under the role of uneven subgrade settlement,the longitudinal maximum tensile stress of the base plate of CRTSⅠslab is greater than that of slab,while the CRTSⅡslab is opposite.Considering the strength of concrete,the settlement control standard of CRTSⅠslab should be based on the tensile stress of base plate,while the settlement control standard of CRTSⅡslab should be based on the tensile stresses of slab and base plate comprehensively.8 tabs,19 figs,25 refs.

关 键 词：铁道工程 无砟轨道 不均匀沉降 受力特性 变形 垂向位移 离缝 

分 类 号：U213.2[交通运输工程—道路与铁道工程]