Abstract:This study aims to discuss the dynamic response of concrete-filled steel tubular arch bridges under vehicle loads. With the Tuzha Bridge in Xiangxi Tujia and Miao Autonomous Prefecture, Hunan Province as the engineering background, an iterative program for numerical analysis of vehicle-bridge coupling vibration was compiled using MATLAB software, and the force of vehicles on the bridge was extracted. The vehicle-bridge coupling vibration of the concrete-filled steel tubular arch bridge was analyzed using the transient dynamic analysis module of ANSYS software. The results show that the first-order frequency decreases for the completely debonded arch rib compared with the fully bonded one. In addition, the first-order vibration mode appears in advance in the plane after the arch rib is completely debonded, and the frequency decrease is greater than that out of the plane. The influence of bridge deck unevenness on the dynamic response of the concrete-filled steel tubular arch bridge is greater than those of other factors. While no obvious law is found in the influence of driving speed on the dynamic response of concrete-filled steel tubular arch bridges, there is a driving speed at which the vehicle resonates with the bridge. For the Tuzha Bridge, the dynamic amplification factor is largest when the driving speed is 20 m/s. The dynamic amplification factor decreases after complete debonding, and the reduction at L/4 (L is length of the bridge) is greater than that at the arch crown.