【摘要】 针对大跨度悬索桥桥塔传统混凝土结构横梁抗剪能力较差的情况,以强震山区主跨1 100 m的悬索桥——泸定大渡河特大桥为背景,计算地震作用下桥塔结构的内力,并对混凝土结构、钢结构、新型波形钢腹板组合结构3种形式桥塔横梁方案进行比选。结果表明:相比于混凝土结构横梁方案,钢结构横梁方案弯矩和剪力减少幅度分别为25.9%～29.3%和33%～34.7%,新型波形钢腹板组合结构横梁方案弯矩和剪力减少幅度分别为17.5%～27.8%和19.1%～30.6%,钢结构横梁与新型波形钢腹板组合结构横梁方案的抗震性能优于混凝土结构横梁方案。但钢结构横梁方案的桥塔横梁钢-混连接构造无法满足结构受力需求,且施工要求高、难度大。新型波形钢腹板方案钢-混连接构造可靠度和施工难易程度优于钢结构横梁方案,因此泸定大渡河特大桥最终采用新型波形钢腹板组合结构横梁方案。更多还原

【Abstract】 In the long-span suspension bridge, the traditional concrete crossbeams for towers usually have poor shear performance.The Luding Dadu River Bridge, which is a suspension bridge located in the mountainous area with high seismicity and has a main span length of 1 100 m, is used as the prototype bridge for this study.The internal forces of the towers under seismic actions were computed, and options of tower crossbeams were compared, including the concrete crossbeam, steel crossbeam and novel composite crossbeam with corrugated steel webs.As per the comparison, the bending moment and shear forces in the steel crossbeam are reduced with degrees of 25.9%-29.3% and 33%-34.7%,respectively, while the two items of the novel composite crossbeam with corrugated steel webs were decreased with degrees of 17.5%-27.8% and 19.1%-30.6%,respectively, in contrast to the concrete crossbeam.The seismic performance of the steel crossbeam and composite crossbeam with corrugated steel webs is superior to that of the concrete crossbeam.However, the utilization of the steel crossbeam is limited by its steel-concrete connection details that are regarded below the load bearing requirements and quite construction challenging.The novel composite crossbeam with corrugated steel webs is a relatively better option in terms of structural reliability and construction challenges, whereupon the novel composite crossbeam with corrugated steel webs was finally chosen for the Luding Dadu River Bridge.更多还原