桁架式拱桥拱肋横桥向风荷载计算方法研究

Study on Calculation Method of Transverse Wind Load on Arch Rib of Truss Arch Bridge

拱桥在面内拥有较大刚度,而在面外结构刚度较低,因此横向风荷载对拱肋作用较为敏感。而桁架式拱桥拱肋形式作为目前大跨径被广泛使用,但《公路桥梁抗风设计规范》[1]并没有提供明确的计算方法。基于前人对桁架式拱桥拱肋横向力系数实验结果,分析探讨规范中给出两种算法(按照桁架形式计算整体的阻力系数;根据杆件计算阻力系数)的适应性与局限。提出了桁架式整体阻力系数与单个杆件计算阻力系数之间的相互转换公式。为桁架式拱桥设计中拱肋横风向风荷载计算提供计算方法。

The arch bridge has greater rigidity in the plane,while the structural rigidity is lower outside the plane.Therefore,the transverse wind load is more sensitive to the action of the arch rib.The arch rib form of truss arch bridge is widely used as a long-span bridge.But a clear calculation method is not provided in Wind-resistant Design Specification for Highway Bridges.Based on the experimental results of the transverse force coefficient of the arch rib of a truss arch bridge,the adaptability and limitations of two arithmetic methods in the code of(calculating the overall resistance coefficient according to the truss form and calculating the resistance coefficient according to the members)are analyzed and discussed.The inter-conversion formula between the overall resistance coefficient of truss and the calculated resistance coefficient of single member is proposed.The calculation method is provided for the transverse wind load calculation of arch rib in the design of truss arch bridge.