Dynamic Performance of Strengthened Concrete-Filled Steel Tubular Arch Bridge due to Moving Vehicles

Abstract

A strengthened concrete-filled steel tubular (CFST) arch bridge which has experienced serious damage due to long-term heavy-truck action is studied. An in-depth study of the dynamic performance of the bridge due to dynamic vehicle loading is performed by field testing and a numerical method. The dynamic performance of the reinforced bridge is more typical and representative than that of new bridges without damage experience. Dynamic field testing is conducted, and the measured data are obtained after strengthening construction for the bridge. The modal parameters and dynamic impact factors are identified, and the proposed three-dimensional vehicle and bridge coupled vibration (VBCV) analysis model is validated based on the experimental results. The influence of vehicular speed, lane position, vehicle weight, road surface condition (RSC), and local damage on the dynamic performance for the bridge due to moving vehicles is studied comprehensively. It is found that the existing design code underestimates the dynamic impact for this bridge. The obvious difference between global and local dynamic amplification effects for the bridge induced by vehicles needs to be given more attention. The dynamic performance of the bridge is not improved distinctly after conventional reinforcement, and some innovative strengthening methods which can improve structural dynamic performance when subject moving vehicles need to be further researched.