大跨简支钢桁架桥梁设计

Design of Long-span Simple-supported Steel Truss Bridge

摘要:

为设计一座跨径为145 m的大跨公路桥梁，提出适用于下承式钢桁架桥的结构方案并验证其合理性。方案采用等高简支钢桁桥，主桁中心间距19.4 m，桁高14.5 m，高跨比为1/10；主桁选用三角形桁式，构件之间采用全焊接连接，以提升整体性与耐久性；桥面系采用正交异性钢桥面板，与主桁下弦结合形成共同受力体系。通过系统阐述结构选型、关键设计参数、计算分析方法及构造细节设计，对结构性能进行全面评估。结果表明：设计方案受力明确、传力路径清晰、结构刚度储备充足、经济性良好，各项计算指标均符合规范要求。

Abstract:

To design a 145-m long-span highway bridge, a structural scheme suitable for through steel truss bridges is proposed and its rationality is verified. The scheme is to adopt an equal-height simple-supported steel truss bridge, the center spacing of the main truss is 19.4 m, a truss height is 14.5 m, and a height-to-span ratio is 1/10. The main truss is selected as triangular truss, and the fully welded connections are used between components to enhance the integrity and durability. The bridge deck system is an orthotropic steel bridge deck, which combines with the lower chords of the main truss to form a common force-bearing system. By systematically elaborating on the structural selection, key design parameters, calculation and analysis methods, and construction detail design, a comprehensive evaluation of structural performance is conducted. The results show that the design scheme has clear force distribution, clear force transfer paths, sufficient structural stiffness reserves, and good economy. All calculation indicators meet the specification requirements.