Study On The Fatigue Performance Of Box Girder With Corrugated Steel Webs Under Vehicle Loading

The tendency of the development of the long-span bridge is very conspicuous in recent years, corrugated steel webs girder has developed rapidly for decades because that it can reduce the weight of the bridge superstructure, perfectly solves the problem of the PC box girder concrete webs crack, significantly enhance the capacity of the bridge span. Bridge is constantly influenced by such factors as vehicle load, wind load and other live loads, the increasing of car traffic volume, the phenomenon of truck or bus overload despite repeated prohibitions, as well as increasing bridge spans, which can increase the possibility of fatigue damage of composite box girder bridge with corrugated steel webs during the operating period. Accordingly, it is necessary to conduct research on the fatigue performance of composite box-girder bridge with corrugated steel webs under vehicle loading.By reference to the theoretical study and fatigue test research of international scholars about steel beams and composite beams with corrugated steel web, and the rules of steel bridge and composite girder bridge at home and abroad specification for structure fatigue calculation, choosing the appropriate fatigue car, traffic volume and structure details level, the paper assesses the fatigue damage and life of the XingTai ZiJin composite box girder bridge with corrugated steel webs during the period using the finite element analysis method. During the operation period of 120 years, under the load of standard fatigue vehicle(UK)、standard fatigue vehicle(recommended in the reference) or 550 kN heavy vehicle(China highway specification), the D value of cumulative fatigue damage of the structural details is far less than 1, the bridge in operating period will not occur fatigue damage, has infinitely long fatigue life.Referring to the cross section form and shape of the ripples of real bridge with corrugated steel webs, this paper adopts the finite element analysis software to establish the entity model of simply supported box girder with corrugated steel webs. By changing the geometric parameters of corrugated web, such as web Angle, models, height and so on, the author studied the effect of geometric parameters on the fatigue property and put forward the methods to improve its fatigue performance. The results show that the impacts of the angle between the corrugated steel web and concrete roof and web thickNess on fatigue performance are the greatest. The degradation of the fatigue performance occurs with the increasing of the angle between the corrugated steel web and concrete roof and the fatigue performance will improve with the increase of the thickNess of the web. In addition, the height of the web exerts effect on fatigue performance to some extent, while the influence on fatigue performance is not significant by using different models of corrugated steel webs.