Influence of cavities on pressure waves inside of high-speed railway tunnels

Newly built railway tunnels are mostly twin-tube tunnels with interconnecting tubes. The interconnecting tubes are closed to the tunnel with safety doors, which can be damaged due to the pressure waves. In this work, the influence of cavities at the side branches on the pressure waves is studied concerning the loads on these safety doors. Moving-model experiments were performed at the Tunnel-Simulation Facility Gottingen. The passage of a train through a tunnel equipped with different cavity configurations was examined. Furthermore, numerical simulations were used to verify the experimental results. It was found, that instead of reducing the pressure at the position of the safety door, the pressure amplitude is increased because of superposition of pressure waves inside of the cavity.