Wind-induced instability of long-sp

Wind-induced instability of long-span steel arch bridges is a serious engineering concern, particularly during construction. Using the Lupu Bridge with a main span length of 550-m as an example, this paper investigates the wind-induced load capacity of a long-span steel arch bridge during two construction stages I and II. Construction stage I is a maximum-cantilevered system before closure of main arch ribs. Construction stage II is a system in which all parts of the bridge have been completed except the stiffening girder of the main span. Three components of wind loads acting on both steel girder and arch ribs are considered in the analysis. The results show that the arch bridge at construction stage II is more susceptible to wind-induced instability than at construction stage I. Finally, various significant parameters affecting wind-induced load capacity are discussed.