Dynamic simulation of sea-crossing bridge under combined service and extreme seismic loads

The in-service sea-crossing bridge handles a large number of vehicles, while considerable wind exists on the superstructure and wave exists on the substructure simultaneously, on a daily basis. Apart from the service loads, the bridges may also encounter extreme natural hazards such as earthquake, hurricane, etc., which might greatly threaten the structural safety. In particular, this article attempts to illuminate the influence of the simultaneous service and extreme loads on the dynamic performance of an in-service sea-crossing bridge along with traversing vehicles. To this end, a general earthquake-wind-wave-vehicle-bridge (EWWVB) simulation platform is established, which systematically integrates the interactions between earthquake, wind, wave, vehicle and bridge. The safety indicators are also implemented in the proposed platform to enable the driving safety evaluations of the vehicles travelling on the bridge during earthquakes. With the proposed simulation platform, an illustrative example is presented in which a number of road vehicles are travelling on an in-service prototype sea-crossing cable-stayed bridge during a sudden earthquake event. The results indicate that the extreme seismic load could become the dominant load affecting the dynamic response of the prototype sea-crossing bridge as well as the vehicles running on it.