高温荷载下植筋加固CRTSⅡ型板式无砟轨道变形及损伤规律  

Deformation and Damage Laws of CRTSⅡSlab Ballastless Track Reinforced by Post-Installed Rebar Subjected to High Temperature Load

作　　者：李杨 陈进杰[1,2,3] 石现峰 王建西[1,2] 王瑞[1,2] LI Yang;CHEN Jinjie;SHI Xianfeng;WANG Jianxi;WANG Rui(State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures,Shijiazhuang Tiedao University,Shijiazhuang Hebei 050043,China;Key Laboratory of Roads and Railway Engineering Safety Control of Ministry of Education,Shijiazhuang Tiedao University,Shijiazhuang Hebei 050043,China;Hebei Key Laboratory of Geotechnical Engineering Safety and Deformation Control,Hebei University of Water Resources and Electric Engineering,Cangzhou Hebei 061001,China)

机构地区：[1]石家庄铁道大学省部共建交通工程结构力学行为与系统安全国家重点实验室,河北石家庄050043 [2]石家庄铁道大学道路与铁道工程安全保障教育部重点实验室,河北石家庄050043 [3]河北水利电力学院河北省岩土工程安全与变形控制重点实验室,河北沧州061001

出　　处：《中国铁道科学》2022年第2期19-27,共9页China Railway Science

基　　金：国家重点研发计划项目(2021YFB2601000);中央引导地方科技发展基金资助项目(216Z3901G);河北省自然科学基金资助项目(E2020210092)。

摘　　要：采用拉拔试验,研究不同强度等级混凝土基材内销钉与混凝土的黏结应力-滑移本构关系,并将其应用于植筋加固CRTSⅡ型板式无砟轨道有限元模型,分析高温荷载作用下植筋加固对无砟轨道变形及损伤的影响规律。结果表明:销钉与混凝土的黏结性能与混凝土强度有关,C30混凝土和C55混凝土试件中销钉与混凝土的黏结应力-滑移本构关系分别可用弹性—滑移—破坏3阶段曲线和弹性—滑移2阶段曲线描述;植筋措施能有效减小轨道板在高温荷载作用下的垂向位移,并将轨道板纵连体的纵向位移分散于轨道板单元内,有利于无砟轨道整体稳定性;高温荷载作用下轨道板垂向位移和层间损伤均随轨道板与砂浆层间黏结强度减小而增大,随窄接缝破损程度增大而增大;高温荷载作用下,植筋黏结失效深度不大于120 mm时轨道板垂向位移随植筋黏结失效深度增加而缓慢增大,大于120 mm时轨道板垂向位移随植筋黏结失效深度增加而显著增大,且邻近破损接缝的轨道板下可能发生超过Ⅲ级限值的层间离缝,植筋黏结失效深度应控制在120 mm以内。Pull-out experiment was conducted to study the bond stress-slip constitutive relationship between the pin and concrete in concrete specimens with different strength grades, and it was applied to a finite element model of CRTSⅡ slab ballastless track reinforced by post-installed rebar. The influence laws of the deformation and damage of the ballastless track reinforced by post-installed rebar subjected to high temperature load were analyzed. Results show that the bond property between the pin and concrete is related to the concrete strength,and the bond stress-slip constitutive relationships between the pin and concrete in C30 concrete specimens and in C55 concrete specimens can be described by the three-stage curve of elastic-slip-failure and the two-stage curve of elastic-slip, respectively. The measure of post-installed rebar can effectively reduce the vertical displacement of the track slab subjected to high temperature load, and can disperse the longitudinal displacement of the longitudinal connected structure for the track slab in the track slab unit, which is beneficial to the overall stability of the ballastless track. Subjected to high temperature load, the vertical displacement and interfacial damage of the track slab increase with the decrease of the bonding strength between the track slab and the mortar layer, and increase with the increase of the narrow joint damage degree. When the bonding failure depth of the postinstalled rebar is not more than 120 mm, the vertical displacement of the track slab slowly increases with the increase of the bonding failure depth of the post-installed rebar under high temperature load. However, when the bonding failure depth is larger than 120 mm, the vertical displacement significantly increases with the increase of the bonding failure depth of the post-installed rebar. Interlayer gaps exceeding the limit of level Ⅲ may occur under the track slab adjacent to the damaged joint, and the bonding failure depth of the post-installed rebar should be controlled within 120

关 键 词：CRTSⅡ型板式无砟轨道 损伤 高温荷载 植筋 黏结应力-滑移关系 有限元分析 

分 类 号：U213.244[交通运输工程—道路与铁道工程]