Numerical Study Of Wave Load On Pile-cap Composite Foundation In Marine Environment

The sea-crossing bridges are usually built in the poor environment.Therefore,it is a great challenge for the construction and the maintenance of the bridge foundation.Most of the sea-crossing bridges are deep-water large span structures,the characteristics of deep water bridge mainly focused on the substructure and the basic form.Compared with inland bridge,the substructure and foundation of deep water bridge are usually subjected to the invasion of dynamic loads such as waves and currents.However,due to the advantage of good seismic performance,high bearing capacity,and small settlement,most of the deep sea crossing bridges adopted the pile-cap-pier foundation.Therefore,this paper mainly studies the wave loads acting on the pile-cap-pier composite foundation.In this paper,by solving the RANS equation and k-s turbulence model,a three dimensional numerical model for wave-composite foundation interactions is proposed based on the CFD code FLOW-3 D.After validated by analytical solutions and experimental data,the effects of the cap submerged depth and the wave obliquity angle on the wave loads acting on the pile-cap-pier composite system are examined.Numerical results indicate that:(1)The present model overall agreed well with analytical solutions and previous experimental data,which can lay a foundation for further investigations.(2)The effects of the submerged depth of the cap on the flow field characteristics around the foundation and wave loads on the composite foundation are examined respectively.According to the numerical results,the variation curves of wave load on composite foundation with the cap submerged depth under different wave conditions are illustrated.(3)The effects of the wave obliquity angle on the flow field characteristics around the foundation and wave loads on the composite foundation are examined respectively.According to the numerical results,the variation curves of wave load on composite foundation with the wave obliquity angle under different wave conditions are illustrated.(4)Based on the study of wave loads acting on Pingtan Strait railway bridge foundation.the influence of the submerged depth and wave obliquity angle are further investigated,which verified the conclusions of the third and the four chapter.The variation curves of the wave loads on the bridge foundation with the submerged depth of the cap and the wave obliquity angle are finally illustrated.