Abstract
This paper deals with vibrational characteristics of a damaged steel arch bridge and application of numerical simulation to stiffening works. Factors for the damages were investigated through field measurement and with numerical simulation. It was recognized that an out-of-plane mode of bridge vibration was predominant due to skew structure and caused damage as the result. Procedure of stiffening on the bridge was studied by using numerical models. The mode causing damages was suppressed by adding members to stiffening. After stiffening works, effects of works were verified on field measurement. The structure without cubic symmetry must be examined of cubic behavior. Numerical simulation is instructive to rehabilitation and stiffening works.
