钢-UHPC轻型组合桥面板实桥试验研究

裴必达 李立峰 邵旭东 王连华 曾研

摘   要：鋼-UHPC轻型组合桥面板是一种由正交异性桥面与密集配筋的UHPC薄层通过剪力钉连接而成的新型桥面结构.为研究UHPC层对钢-UHPC轻型组合桥面结构性能的影响，以枫溪大桥为工程背景，研究正交异性钢桥面常见疲劳细节在铺设UHPC层前、后的应力幅变化.首先通过整体有限元模型确定测点位置以及加载范围，然后根据加载方案分别在铺设UHPC层前后采用三轴加载车进行低速加载试验，同时采集并整理正交异性钢桥面常见疲劳细节应力响应试验数据，最后建立了节段有限元模型并与实测结果进行对比分析.试验结果表明：铺设UHPC层后，常见疲劳细节应力响应均有明显降低，其中面板上的细节（纵肋-面板焊缝、面板对接焊缝、面板-横隔板-纵肋交叉焊缝面板位置）应力幅降幅比例最大，高达75%～90%;其次为纵肋上疲劳细节（纵肋底部对接焊缝、纵肋-横隔板焊缝焊缝端部位置、面板-横隔板-纵肋交叉焊缝纵肋位置）应力降幅约为65%～80%;最后为横隔板上疲劳细节（横隔板弧形切口、横隔板弧形切口起点位置、面板-横隔板-纵肋交叉焊缝横隔板位置）应力降幅约为20%～50%.同时，随疲劳细节与顶面距离的减小，UHPC层对细节应力降幅的贡献明显增大.有限元模型结果与实测结果吻合较好，也得出了相似的规律.本文实测结果为推广钢-UHPC轻型组合桥面的应用提供了最直接的数据参考.

关键词：桥梁工程;轻型组合桥面板;现场试验;疲劳细节;应力幅;UHPC层

中图分类号：U443.33                        文献标志码：A

文章编号：1674—2974（2019）01—0076—09

Abstract： The steel-UHPC lightweight composite deck is a novel bridge deck pattern that consists of an orthotropic steel deck（OSD） and a thin ultra-high performance concrete（UHPC） layer. In order to reveal the effect of UHPC layer on the performance of the OSD， field measurement was performed for Fengxi Bridge to evaluate the stress ranges in the typical detail categories of the OSD with/without UHPC layer， respectively. Before the field measurement was conducted， the global finite element model of Fengxi Bridge was developed to determine the instrumented sections. Then， a triaxial loading vehicle， according to the loading scheme，was arranged to run on the bridge deck with/without UHPC layer at a low speed， respectively. The field measurement data of the typical detail categories were collected and sorted. Finally， a local finite element model of Fengxi Bridge was built to compare with the field measured results. The field measurements show that the stress response of the typical detail categories are significantly reduced after installment of UHPC layer. For the detail categories related to the steel deck（i.e.， rib-to-deck weld， deck splices， and deck of rib-to-deck at diaphragm joint），the stress range decreased by about 75% ～ 90%;for the detail categories related to the trapezoidal rib（i.e.， rib splices， weld end of rib-to-diaphragm joint， and rib of rib-to-deck at diaphragm joint），the stress range decreased by about 65% to 80%; for the detail categories related to the diaphragms（i.e.，cut-out on diaphragm， diaphragm base metal at cut-out transition， and diaphragm of rib-to-deck at diaphragm joint），the stress range decreased by about 20% to 50%. Meanwhile， with the decrease of the distance from detail categories to top surface， the contribution of UHPC layer to the stress reduction of the detail categories was significantly increased. The results of the local finite element model agreed well with the measured results， and the similar rules were obtained. The field measured results of this paper provide the reference data for the application of steel-UHPC lightweight composite bridge deck.