两座连续梁拱组合桥设计分析比较

连续梁拱组合桥兼顾了梁桥与拱桥的特点,结构体系新颖,受力复杂,造型优美,近年来得到广泛应用。现详细介绍徐海路沭河大桥和城南大桥的总体布置、主要构造、施工方法、可为同类桥设计、研究、施工提供有益参考。并对两座桥的设计参数及受力特点进行对比分析,包括边中跨比、拱梁刚度比、拱梁荷载比、拱梁弯矩比及结构体系的界定等。根据拱梁的抗弯刚度比,连续梁拱组合桥可分为刚拱柔梁、刚拱刚梁和柔拱刚梁3种组合体系,不同组合体系结构设计方法不同,主梁、拱肋可根据不同体系的传力特点和拱梁荷载分配比进行优化设计。连续梁拱组合桥边中跨比变化范围较大,设计灵活,可适应不同环境、景观需求。

Analysis and Comparison on Designs of Two Continuous Beam-arch Composite Bridges

Continuous beam-arch composite bridge takes into account the characteristics of beam bridge and arch bridge. Its structural system is novel, its stress is complex and its shape is beautiful. In recent years, it is widely used. The overall layout, main structures and construction methods of Shuhe Bridge on Xuhai Road and Chengnan Bridge are introduced in detail, which can provide the useful reference for the design, research and construction of similar bridges. The design parameters and mechanical characteristics of the two bridges are compared and analyzed, including the side to mid span ratio, the arch-beam rigidity ratio, the arch-beam load ratio, the arch-beam bending moment ratio and the definition of the structural system. According to the bending rigidity ratio of arch and beam, the continuous beam-arch composite bridge can be divided into three kinds of composite systems: rigid arch flexible beam, rigid arch rigid beam and flexible arch rigid beam. The structural design methods of different composite systems are different. The design of the main beam and arch rib can be optimized according to the transmission characteristics of different systems and the load distribution ratio of arch beam. The side to mid span ratio of the continuous beam-arch composite bridge has a wide range of changes. The design is flexible, and can adapt to the different environment and landscape needs.