The Influence Of Foundation Scouring On The Seismic Performance Of A Bridge Under The Background Of Climate Change

The bridge is an integral part of the modern transport system, the influence of climate changes cannot be ignored. In recent years, climate change is significant, more and more researchers begin to study the influence on bridge caused by climate changes; however, it is not deep enough. In this paper, the influence of scour of foundation caused by climate change has been considered on the seismic performance. And it is essential from both perspectives of theory and practical project application.According to the A1B、 A2and B1scenarios gave by Intergovernmental Panel on Climate Change, for global consideration, fluvial runoff" increased in the Asian region. Taking a railway bridge as an example, changes of the pier scours depth under the conditions of future climate have been forecasted. Then, in order to study the influence of foundation scour on dynamic performance of bridge, several methods considering SSI have been comparatively analyzed, a reasonable layered soil model has been adopt. According to the forecast of the scour depth, buried depth of the pile foundation has been changed and the corresponding soil spring number and stiffness has been reduced, the comparative analysis of the seismic response had been made by the response spectrum method and the time history analysis method. Pushover analysis has been applied to calculate the seismic performance of bridge pies under different climate change scenarios and distribute lateral load patterns. The main results are given in follow: With the depth of scour is continuously increasing, the structure stiffness is reduced and the earthquake response increased, especially on the pier top, the restriction of the soil around the pile was lost and bending moment grows apparently.Comparing the pushover curve under different scour depth, with increasing of the scour depth, corresponding lateral force shrunk while horizontal displacement on the pier top is increased.With the vibration response of bearing platform and pile foundation increasing,plastic hinge continuously shift down. And higher modes influences are considered in distribute lateral load patterns of push-over analysis.