Bridge pier under coupled earthquake and wave - Current actions: Numerical model establishing, optimization and structural response analysis

Abstract

Bridges located in earthquake-prone areas may be subjected to earthquake, wave and current actions simultaneously. Current investigations on bridge piers under these complex loading conditions were generally performed through underwater shaking table (UST) tests, which required advanced test setups and great expenses. With the aim of eliminating these limits and developing a comprehensive understanding of the performance of deep-water bridge piers under coupled earthquake and wave-current actions, the present study carried out systematic numerical investigations. Wave generation and propagation were first simulated, for which thorough sensitivity analysis was conducted to obtain the optimal parameters, including mesh size, time step intervals, damping zone length and damping coefficients. Numerical models which are able to simulate nonlinear wave-current interactions were then established and validated. Following this, structural responses of bridge piers under wave, wave-current and coupled earthquake and wave-current actions were numerically simulated and validated by test results. Finally, parametric analysis was conducted on a pile of a practical deep-water bridge in China using the validated model with consideration of various water depth levels, diverse wave heights, different current velocities, varied earthquakes and different peak ground accelerations to reveal the influence of different excitation parameters on structural responses.