Analysis method of dynamic response in the whole process of the vehicle bump test of simply supported bridge

Abstract

For medium- and small-span bridges, the vehicle bump test is one of the most commonly used excitation methods, dynamic response of which can provide theoretical support for the dynamic load test. This article presents a dynamic response analysis method for the whole process of the vehicle bump test. First, the process of vehicle bump is divided into three stages based on transformation of the vehicle–bridge contact condition, including the static state before vehicle bump, the process of vehicle bump, and the free-decay vibration after vehicle bump. Second, the vibration equations of each stage are established, respectively, on the basis of the characteristics of vehicle–bridge coupling vibration. Then, the starting time and initial conditions of each stage are determined and the dynamic response is estimated by the fourth-order Runge–Kutta method. Finally, a field experiment is carried out; the error of the maximum strain value between the proposed method and the test method is less than 15%, which perfectly verifies the reliability of the method. The dynamic response of a T-shaped simply supported bridge of the whole vehicle bump process is solved by numerical simulation which indicates that the proposed method can provide theoretical basis for the choice of vehicle bump height.