Dynamic Response Analysis Of Structure-Seabed Coupled System Under Wave-Current

Analysis of structure response under wave and current impact is an important topic in the study of Marine structures.The collapse of Marine structures under the action of wave current is often related to the failure of seabed.Therefore,it is necessary to consider the dynamic interaction between saturated seabed and structure under the wave current load.In this paper,a method for analyzing the interaction between saturated seabed and structure under the combined of wave and current is presented.The main work is as follows:(1)Based on the finite volume method,fluent fluid calculation software was used to simulate two-dimensional wave current propagation.A two-dimensional numerical flume model was constructed.The velocity wave was generated by the UDF function at the inlet,and the phase boundary was tracked by the VOF method.The source term function was set to eliminat wave at the outlet.The simulation calculation of regular wave is carried out,and the liquid surface height of inlet and outlet area under three working conditions is extracted and compared with the analytical solution.Which verifies the feasibility and accuracy of wave generation of two-dimensional wave current.(2)Basised on two-dimensional numerical simulation,a three-dimensional calculation model is further established,based on the flume experiment of plate physics,the three-dimensional numerical flume modeling and analysis were carried out,and the floating force of fluid on the bottom of plate was calculated.The wave current load simulation analysis is carried out on the main pier structure of a cross-sea bridge model,The floating support force and pile horizontal force of bridge pier structure are studied under different tide difference conditions and different water level heights,The feasibility of wave current calculation for practical engineering is discussed by comparing with the experimental data of physical flume,verify the validity of numerical simulation of three-dimensional wave current.(3)Based on Biot porous media model,the dynamic response of saturated seabed under three-dimensional wave-flow loading is analyzed by using concentrated mass explicit finite element method and multiple transmission artificial boundary.The saturated soil is considered as linear and nonlinear,The Davidenkov skeleton curve model modified by the "extended Masing" principle is used to describe the non-linearity of saturated soil skeleton,and the response of saturated seabed under different wave current conditions is analyzed.(4)Soil FORTRAN program was developed to analyze the interaction between the saturated seabed and the structure under the combined action of wave and current,and an actual sea-crossing bridge was analyzed.The saturated seabed was simulated by the concentrated mass explicit finite element method combined with multiple transmission boundaries,and the superstructure was analyzed by the implicit time-step integral method,seabed and structure coupled by foundation with different time steps.An actual pier model of a sea-crossing bridge is analyzed,and the practicability of this method is demonstrated.