16.09: Influence of arch bridge skewness

Abstract

ABSTRACTThis article performs a parameter study on a detailed finite element model of a simple arch bridge consisting of a single arch. The objective is to investigate the influence of different hanger arrangements, dimensions and finally a variation of the angle of skewness between the arch axis and longitudinal bridge deck axis. The influence on the stresses, forces and bending moments in the bridge deck girders, hangers and arch is examined. Finally, a buckling analysis is performed on all different models and the change in critical buckling load is discussed.The displacements in the bridge deck stay the same for small angles of skewness. Starting from an angle of ± 13°, the position of maximum deflection in the bridge deck shifts towards the ends of the bridge deck instead of being situated staying in the middle. This can be explained by the influence of the wind load acting on the arch structure and the direction of the horizontal resultants of the hanger forces. This can cause partial relaxation, thus ensuring a small uplift at the longitudinal girders of the bridge deck. This is also the cause for the higher displacements in the arch. The torsion effect in the arch results in a counter clockwise rotation of the arch. When performing a buckling analysis on the changing angle of skewness, it is found that this initially has only a small impact on the critical load factor.