| In recent decades,in order to meet the conditions needed for survival and development,human exploration and development of the oceans have been intensifying.In this process,marine engineering facilities such as offshore drilling platforms,offshore wind facilities,submarine tunnels,submarine pipelines and other marine engineering facilities have been built in large numbers on the offshore continental shelf to meet human needs for energy,resources,transportation and other aspects.However,these marine engineering facilities have been affected by wave loads,seismic effects and other natural factors since they were established on the seabed,and damage to the facilities often occurs,resulting in economic losses and casualties.In order to prevent and reduce the damage of marine engineering facilities and mitigate the loss of life and property,research on the dynamic response of the seabed has gradually emerged.In the previous research on seabed dynamic response,Biot porous media theory was commonly used.However,most of these studies are based on the basis of good contact between the dynamic water pressure of seawater and the pore water pressure of the seabed.In fact,the flow-solid interface between seawater and the seabed can occur with insufficient hydraulic contact due to the presence of silt,clay and other sediments.To address this situation,a generalized flow-solid interface condition is used in this paper to establish a seawater layer-seabed sediment layer model to investigate the dynamic response of the seabed sediment layer under seismic action.The main work is summarized as follows:(1)A seawater layer-seabed sediment layer model using generalized flow-solid interface conditions is established based on the Biot porous medium theoretical model.(2)A semi-analytical solution of the transient response of the saturated seabed sediment layer with generalized fluid-solid interface conditions is derived using the transfer matrix method with Laplace transform and inversion method.With the help of this solution,the effect of the flow-solid interface condition on the two types of compressional waves propagating in the seabed sediment layer is discussed.(3)An analytical solution of the steady-state response of the saturated seabed sediment layer using generalized interface conditions is derived.With the help of this solution,the effect of the flow-solid interface condition on the dynamic response of the saturated seabed sediment layer with the variation of the incident wave frequency and the variation of the depth along the seabed is investigated.(4)An analytical solution for the steady-state response of the near-saturated seabed sediment layer using the generalized interface conditions is derived.With the help of this solution,the effect of the flow-solid interface condition on the dynamic response of the near-saturated seabed sediment layer with the variation of the incident wave frequency and the variation of the depth along the seabed is investigated. |
