Flow Characteristics And Dynamic Response Analysis Of Deep-water Bridge Piers In Deepwater Area

With the continuous advancement of national infrastructure construction,deep-water bridges continue to emerge,many of which are cross-sea bridges.The water environment of the deep-water bridge is very complex.The fluid-solid coupling effect between the complex hydrodynamic environment and the substructure will significantly affect the dynamical response of structure.Thus it,the research on the flow characteristics and dynamic response of deepwater pier has important engineering application value.Based on the existing analysis theory of water-structure interaction,numerical simulation analysis based on fluid element method is adopted to carry out the following work :(1)Using the finite element analysis software COMSOL-CFD,LES is used to simulate the 2D analysis flow around circular cylinder,rounded shape and rectangle.The results show that the flow field of rectangle is more complex than that of circle and rounded shape,and vortex shedding in front and back ends of rectangular piers,and the strength of the shedding vortex increases because it intersects in the zone of wake.The influence of rectangle on the distribution of flow field is significant,followed by the rounded shape,and the round is minimum.(2)Using the finite element analysis software ADINA fluid-solid coupling analysis module(FSI),three-dimensional numerical simulation analysis of wave-current coupling of rectangular,rounded shape and circular hollow piers.The results show that under the action of different flow velocity and wave height,the internal force of rectangular pier is the largest,the rounded shape pier is the second,and the circular pier is the smallest.The differential value of moment stability and shear stability at the bottom of rectangular pier and rounded shape pier decreases with the increase of flow velocity.The differential value of bottom moment stability value and bottom shear stability value between round pier and rounded shape pier increases with the increase of flow velocity.When the wave crest and trough act on the three types of piers respectively,the difference of dynamical response does not change monotonously with the wave height.(3)The model of double circular hollow pier with different inflow direction is established,three-dimensional numerical simulation analysis of wave-current coupling of double circular hollow pier.The double piers in the flow field are affected by the shielding effect.Along the flow direction,the dynamical response of the front pier(upstream pier)is larger than that of the rear pier(downstream pier),and Positive correlation between differential value of dynamical response of the two piers and flow velocity.In the wave field,with the increase of the wave propagation angle.Under the action of wave crest,the weakening effect of shielding effect on wave force is always greater than the enhancement effect of diffraction effect.However,under the action of trough,the weakening effect of shielding effect on wave force is gradually smaller than the enhancement effect of diffraction effect.