沪苏通长江大桥铁路UHPC组合桥面铺装层厚研究  

Research on Pavement Thickness for Railway UHPC Composite Deck of Shanghai-Suzhou-Nantong Yangtze River Bridge

作　　者：郭福宽 周尚猛 GUO Fukuan;ZHOU Shangmeng(State Key Laboratory for Health and Safety of Bridge Structures,Wuhan 430034,China;China Railway Bridge Science Research Institute,Ltd.,Wuhan 430034,China)

机构地区：[1]桥梁结构健康与安全国家重点实验室,武汉430034 [2]中铁大桥科学研究院有限公司,武汉430034

出　　处：《铁道标准设计》2022年第6期73-77,共5页Railway Standard Design

基　　金：中国中铁股份有限公司科技研究开发计划项目(2018-重点-10,2019-重大-05)。

摘　　要：针对现有铁路钢桥面铺装不足问题,沪苏通长江大桥采用UHPC组合桥面铺装方案,其厚度直接影响组合桥面铺装的工作性能。为研究合理的厚度,选取典型UHPC层厚建立有限元模型计算分析,对比UHPC层应力情况及钢桥面板构造细节的疲劳应力幅变化情况,进而探讨合理UHPC层厚度,并对组合桥面进行模型试验,验证其抗渗性能。结果表明:3种厚度UHPC层均能有效抵抗荷载作用产生的拉应力,表面裂纹宽度控制在0.05 mm以内,同时,可显著降低钢桥面板细节疲劳应力幅,降幅达72.2%,基本消除疲劳开裂风险;桥面局部刚度随着UHPC层厚增加而增大,当UHPC层厚度介于50~60 mm时,肋间挠度降幅接近90.0%,对钢桥面板应力改善效果明显;当UHPC层表面裂纹宽度达到0.05 mm时,裂纹随水压增加而闭合,在2.0 MPa水压下无渗水现象。因此,UHPC层厚度为50~60 mm时,组合桥面铺装能够达到良好的受力状态且满足抗渗要求。In view of the deficiency of existing railway steel deck pavement, the UHPC composite deck pavement scheme is adopted for Shanghai-Suzhou-Nantong Yangtze River Bridge. The thickness of UHPC layer directly affects the performance of composite bridge deck pavement. In order to study the reasonable thickness, typical UHPC layer thickness is selected to establish a finite element model for calculation and analysis. The stress of UHPC layer and the fatigue stress amplitude variation of steel bridge deck structural details are compared, and then reasonable UHPC layer thickness is discussed. The model test of composite bridge deck is carried out to verify its impermeability. The results show that three UHPC layers of different thickness can all effectively resist the tensile stress produced by the load, and the surface crack width is controlled within 0.05 mm. Meanwhile, the fatigue stress amplitude of the steel bridge deck can be significantly reduced by 72.2%, which basically eliminates the risk of fatigue cracking;When the thickness of UHPC layer is between 50~60 mm, the deflection between ribs decreases by nearly 90.0%, which improves the stress of steel deck obviously;When the surface crack width of UHPC layer reaches 0.05 mm, the crack closes with the increase of water pressure, and there is no water seepage under 2.0 MPa water pressure. Therefore, when the thickness of UHPC layer is 50~60 mm, the composite bridge deck pavement can achieve good stress state and meet the requirements of impermeability.

关 键 词：铁路桥 斜拉桥 桥面铺装 UHPC层 有限元模拟 抗渗性能试验 

分 类 号：U443.33[建筑科学—桥梁与隧道工程] U446.1[交通运输工程—道路与铁道工程]