大跨度系杆拱桥主拱钢-混凝土结合段受力状态分析

以鹰潭市余信贵大跨度中承式钢管混凝土系杆拱桥为研究对象,利用有限元软件分别建立大桥整体数值模型与钢-混凝土结合段局部实体数值模型,计算分析主拱钢-混凝土结合段在设计荷载作用下的受力状态与承载能力。分析结果表明:在持久状况荷载组合下,主拱肋钢-混凝土结合段模型变形连续,最大变形量为0.030 m,主拱肋钢-混凝土结合段结构刚度及变形满足要求;钢-混凝土结合段混凝土最大拉应力为1.63 MPa,钢结构部分Von-Mises等效应力最大值为236 MPa,均小于容许应力,满足结构设计要求;为避免应力集中,须对钢-混凝土结合段的坡口进行细化设计,或调整主跨系杆的张拉力。

Analysis on Stress-Strain Conditions of Steel and Concrete Combined Segment of Main Arch for Long Span Tied Arch Bridge

Taking Yingtan Yuxingui long span concrete-filled steel tubular tied arch bridge as the research object,the overall numerical analysis model of the bridge and the local solid numerical model of the steel-concrete combined segment were established by using the finite element software to calculate and analyze the stress-strain state and bearing capacity of the main arch steel-concrete combined segment under the design load. The results show that the deformation of the steel-concrete combined segment of the main arch rib is continuous,the maximum deformation is 0.030 m,the stiffness and deformation of the steel-concrete combined segment of the main arch rib meet the requirements. The maximum tensile stress of the concrete of the steel-concrete combined segment is 1.63 MPa,and the maximum equivalent stress of the Von-Mises of the steel structure is 236 MPa,both of which are less than the allowable stress,meeting the structural design requirements. In order to avoid stress concentration,it is necessary to refine the groove design of the steel-concrete combined segment,or adjust the tension of the main span tie bar.