端横撑位置对钢拱桥面外极限承载力的影响

针对主跨428 m的广州新光大桥设计方案,采用大型有限元软件ANSYS建立全桥三维有限元模型,分析横撑的数量和位置对弹性稳定和面外极限承载力的影响。结果表明,在端横撑位置确定的情况下,极限承载力随横撑数量增加先增大后降低;在横撑数量相同的情况下,端横撑位置对大跨度钢桁拱的弹性稳定和面外极限承载力影响显著,且端横撑的位置对弹性稳定的影响大于对面外极限承载力的影响。因此,在景观要求允许的情况下,端横撑应尽量向拱脚靠近。

The Effect of End Bracing Location on Out-of-Plane Ultimate Bearing Capacity of Steel Arch Bridges

Based on a case study for Xinguang Bridge with the main span of 428 m in Guangzhou,a three-dimension FEA model is established by ANSYS.The effects of the number and location of bracings on the elastic stability and the ultimate bearing capacity are analyzed.Results show that when the location of end bracings is determined,the ultimate bearing capacity will first increase and then decrease along with the increasing numbers of bracings.While the number of bracings is identical,the location of end bracings will influence the elastic stability and out-of-plane ultimate bearing capacity of steel arch bridges notably.The effect of the end bracing location on the elastic stability is more obvious than on out-of-plane ultimate bearing capacity.So if the landscape of bridge is permitted,the end bracing should be as close to the arch end as possible.