Investigation on the Dynamic Response of a High-Speed Railway Tunnel Located Beneath an Airport Runway and Uneven Settlement of the Runway

The rapid development of the high-speed railways and air transportation networks is leading to an increasing demand of the combination of these two modes of transport. Some modern integrated transport hubs have been operated, and at least 32 airports in China are planning to combine air transportation with high-speed railway transportation. To realize the “seamless transfer” between the airport and the high-speed railway station, some high-speed railways were constructed beneath airport runways. It is necessary to study the dynamic interaction between these two kinds of infrastructures. Based on a project with a high-speed railway tunnel beneath an airport pavement in south China, an aircraft–runway interaction model and a vehicle-tunnel-foundation coupling model are proposed to investigate the dynamic response of the complete system. In this paper, the cumulative plastic deformation of the airport runway caused by the dynamic load of high-speed trains is comprehensively predicated. The influence of the aircraft dynamic load on the deformation of the tunnel and the operation safety of high-speed trains is investigated. The results show that the settlement of airport runway rises to 9.80 mm after ten years of operation of the high-speed railway. The amplitudes of the vertical and horizontal displacement of the tunnel affected by the aircraft dynamic load are 0.192 mm and 0.099 mm, respectively. The rate of wheel load reduction of the high-speed train is not evidently excited by the aircraft dynamic load.