Evaluating the Reactions of Bridge Foundations to Combined Wave–Flow Dynamics

Abstract

As the ongoing development of national infrastructure progresses, we see an increase in the construction of deep-water bridges, specifically cross-sea bridges. This paper uses Stokes’s wave theory to simulate and analyze how a bridge foundation dynamically responds to wave–fluid interactions. Firstly, the governing equations, boundary conditions and initial conditions of fluid motion are derived, expanded and solved via Stokes’s wave theory, and a spectral model is simulated and plotted. Based on the P-M spectrum and equal frequency method, a method of wave height attenuation during wave propagation is proposed. Using an SSTK-ω turbulence model, a numerical wave flume is established considering the fluid model, the selection of element type and the boundary conditions set, and the influencing factors of wave propagation (attenuation) are analyzed. Waves with different wave parameters (period, depth and height) are numerically simulated and compared with the theoretical values. Finally, we perform an analysis of the dynamic response under wave–current coupling conditions. We establish different operational scenarios and obtain the following results: under a load duration of 200 s, the peak transverse displacements for spans 1, 2 and 3 measure at 0.84 m, 0.63 m and 0.62 m, respectively. The peak transverse displacements under operational scenarios 2 and 3 show reductions of 25.0% and 25.7%, respectively, when compared to scenario 1. However, large transverse displacements remain. This suggests that the influence of waves and water flow on the transverse displacement of the main span should not be overlooked.