不同拱轴线反拱基础框架桥力学特性

Research on Mechanical Characteristics of Reverse Arch Foundation Frame Bridges with Different Arch Axes

基于框架桥整体性好、刚度大等优点,针对深厚海相淤泥软土地质场地设计了一种反拱框架桥结构。为获得其合理的结构形式,通过对反拱基础框架桥进行应力和变形规律分析,研究不同反拱轴线底板的反拱框架结构力学特性并进行比选。利用ABAQUS有限元软件建立3种反拱基础框架桥模型,在结构自重和车道荷载的作用下,计算获取结构主应力和沉降、变形数据。结果表明:该结构的最大主拉应力出现在与桥墩连接处的顶板上表面;最大竖向变形发生在顶板中跨跨中;最大纵向变形发生在墩顶塑性铰区范围。在相同条件下,最大主拉应力、竖向和纵向变形均出现在圆弧拱轴线桥,分别为2.272 MPa,2.428 mm和0.131 mm;但最大沉降出现在抛物拱轴线桥,为6.913 mm。因此,悬链拱轴线桥的受力性能相对更加合理,结构变形较小,更适合后期的应用推广。基于此,根据结构受力和变形特征,建议在结构设计时宜优先考虑使用悬链拱轴线底板的反拱基础框架桥。

Based on the advantages of good overall integrity and high stiffness of the framework bridge,this study proposes a reverse arch framework bridge structure designed for deep-sea sediment soft soil geological sites.To obtain a reasonable structural form,stress and deformation patterns of the reverse arch foundation framework bridge were analyzed.Based on this,the mechanical properties of different arch axis bottom plates of the reverse arch framework structure were compared.Three types of reverse arch foundation framework bridge models were established using ABAQUS finite element software.Under the influence of structural self-weight and roadway loads,principal stresses,settlement,and deformation data were calculated.The results show that the maximum principal tensile stress occurs on the upper surface of the top plate connected to the bridge pier.The maximum vertical deformation occurs in the middle of the top plate span.The maximum longitudinal deformation occurs in the plastic hinge zone of the pier top.Under identical conditions,the maximum principal tensile stress,vertical,and longitudinal deformations all occur in the circular arch axis bridge,at 2.272 MPa,2.428 mm,and 0.131 mm respectively.However,the maximum settlement appears in the parabolic arch axis bridge,at 6.913 mm.Therefore,the stress performance of the catenary arch axis bridge is relatively reasonable,with smaller structural deformations,making it more suitable for later application and promotion.Based on this,it is recommended to prioritize the use of the catenary arch axis bottom plate for the reverse arch foundation framework bridge during structural design,considering the structural stress and deformation characteristics.