Impact-induced vibration effects on the real dynamic behavior of cable-stayed bridges

Abstract

Cable-stayed bridges are flexible and complex structures. Impact-induced vibrations may play an important role on the behaviors of the structural elements. Many efforts have been devoted to clarifying the experimental static and dynamic responses of cable-stayed bridges. However, experimental dynamic responses of structural elements of cable-stayed bridges under impact-induced vibrations have not been addressed widely in the literature. The paper focuses on the real experimental dynamic behaviors of cables, deck, and pylon in cable-stayed bridges under impact-induced vibration effects due to fully loaded trucks passing over a bump positioned on the deck center. The tests have been implemented on the new Kömürhan cable-stayed bridge under the passage of two-40 ton trucks. The thickness of the timber bumps and speed of the trucks are selected as 50mm and 30km/h, respectively. The dynamic responses of the structural elements have been recorded using load cells, 2D and 3D accelerometers. Forces, accelerations and frequencies of the main and back span cables, and acceleration responses of deck and pylon recorded with and without impact effects are evaluated and compared with each other. Significant impact-induced amplification ratios on the responses of the main and back span cables, deck and pylon are observed on the selected bridge.