某山地螺旋吊桥结构分析与设计

Structural Analysis and Design of a Spiral Suspension Bridge in a Mountainous Region

螺旋吊桥有效地解决了陡坡段山地步道落地问题,同时结构新颖、美观。螺旋吊桥纵向计算可以理解为曲率较大的弯桥建立梁单元进行分析。为了结构有更好的人行空间和视线,采用吊杆与主梁内侧连接的方式,导致主梁在人群荷载作用下产生横向扭矩,有倾覆的趋势,横向分析不能忽视。该结构为螺旋状,有别于常规端部约束的直梁在扭矩作用下产生扭转剪应力。在均匀满布的人群荷载作用下,主梁各个位置的扭转变形一致,扭转剪应力不明显,表现出的是主梁横向受弯问题,与横向刚度息息相关。进而建立不同横隔板道数的三维板单元模型进行分析计算,以确定合理的横隔板数量,为类似工程提供参考。

Spiral suspension bridge effectively solves the problem of landing on steep mountain trails, and has a novel and beautiful structure. The longitudinal calculation of spiral suspension bridge can be understood as the establishment of beam elements for analysis of curved bridges with larger curvature. In order to have a better pedestrian space and line of sight for the structure, the method of connecting the boom and the inner side of the main girder is adopted, which causes the main girder to generate the lateral torque under the action of the crowd load, and there is a tendency of overturning, which cannot be ignored in the lateral analysis. This structure is helical, which is different from the conventional straight beams with end restraints that produce the torsional shear stress under the action of torque. Under the uniform crowd load, the torsional deformation of the main girder is the same at all positions, and the torsional shear stress is not obvious, which shows the problem of the transverse bending of the main girder, and is closely related to the lateral rigidity. Furthermore, a three-dimensional plate element model with the different numbers of diaphragm plate is established for analysis and calculation to determine a reasonable number of diaphragm plates and provide the references for the similar projects.