Fatigue Testing of Traffic Tunnel Panels

An original method is presented for fatigue testing of tunnel panels that are dynamically loaded by pressure waves caused by car and truck traffic. The dynamic pressure load on the tunnel walls is measured at the site and simulated in a real-size laboratory testing procedure, in which pressure and suction loads are generated by a bellow system. The bellow system simulates the maximum loads caused by vans and small trucks. Additionally, a high frequency load is applied by means of a vibrator placed in the antinode of the most important mode shape of the panel system. The loading frequency is imposed close to the corresponding natural frequency of the panel and fixation system. In this vibration loading, the behavior of the panel system during the real life span is controlled. The testing system allows for optimization of both the panel composition and the attachment system.