腹板斜裂缝对重载铁路32 m跨度预应力混凝土T梁受力影响仿真分析  

Simulation Analysis on Influence of Web Inclined Crack on Stress of 32 m⁃span Prestressed Concrete T⁃girder of Heavy Haul Railway

作　　者：许见超 葛凯 王振 朱希同 袁磊 荣峤 XU Jianchao;GE Kai;WANG Zhen;ZHU Xitong;YUAN Lei;RONG Qiao(Railway Engineering Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China;State Key Laboratory of High-speed Railway Track Technology,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China)

机构地区：[1]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081 [2]中国铁道科学研究院集团有限公司高速铁路轨道技术国家重点实验室,北京100081

出　　处：《铁道建筑》2022年第4期64-67,共4页Railway Engineering

基　　金：中国铁道科学研究院集团有限公司基金(2019YJ043)。

摘　　要：针对出现腹板斜裂缝的重载铁路32 m预应力混凝土简支T梁(图号:专桥2040),分别假定4种不同斜向开裂状态并建立实体有限元模型,对运营荷载作用下在距梁端4~8 m的(斜裂缝纵向分布区域)腹板混凝土主拉应力、预应力钢束和箍筋应力,以及跨中挠度进行计算分析。结果表明:腹板斜裂缝对梁体受力影响显著,与完好梁体相比,预设斜裂缝深度至一半腹板厚度时,斜裂缝相交处箍筋的应力大幅增长,但满足规范限值;腹板混凝土主拉应力超过规范限值,存在腹板斜裂缝进一步发展的风险;当预设斜裂缝贯通腹板时,运营荷载作用下箍筋最大拉应力及活载作用下箍筋最大应力幅远超规范限值。对于重载铁路出现腹板斜裂缝病害的梁体应密切关注其斜裂缝发展趋势,斜裂缝深度超过一半腹板厚度的梁体应进行受力检算和评估。For the 32 m-span prestressed concrete simply supported T-girder of heavy haul railway with web inclined cracks(drawing No.:special bridge 2040),four different inclined cracking states were assumed respectively,and the solid finite element model was established to calculate and analyze the main tensile stress of web concrete,the stress of prestressed tendon and stirrup and the mid-span deflection in the area 4~8 m away from the girder end(the longitudinal distribution area of inclined cracks)under the action of operating load.The results show that the web inclined crack has a significant impact on the stress of the girder.Compared with the intact girder,when the inclined crack depth is preset to half the web thickness,the stress of the stirrup intersected by the inclined crack increases greatly,but meets the code limit.The principal tensile stress of web concrete exceeds the limit value of the code,and there is a risk of further development of inclined cracks in the web.When the inclined crack is preset to pass through the web,the maximum tensile stress of stirrup under operating load and the maximum stress amplitude of stirrup under live load far exceed the specification limit.The girder with web inclined crack defects in heavy haul railway should pay close attention to its inclined crack development trend.The girder with inclined crack depth more than half of the web thickness should be checked and evaluated.

关 键 词：重载铁路桥梁 腹板 斜裂缝 裂缝深度 数值模拟 T梁抗剪 性能评估 

分 类 号：U448.13[建筑科学—桥梁与隧道工程]