波流共同作用下海底管线周围海床的动力响应分析

Numerical Analysis of Dynamic Responses of a Porous Seabed around Pipelines Subjected to Wave and Current Loading

针对埋设有海底管线的多孔介质海床,基于Biot动力固结理论,采用Pastor-Zienkiewicz III的动力弹塑性本构模型,建立了一个多孔介质的弹塑性海床模型,分析了波浪-海流共同作用下海底管线周围海床的动力响应规律,计算了波浪-海流共同作用下海床中超孔隙水压力的分布和表面波压力的分布规律,以及不同的海流速度对海床中超孔隙水压力分布的影响。结果表明:海流的存在对海床表面的波压力的波长和周期都有显著影响;海底管线等结构物的存在,减缓了管线以下海床中超孔隙水压力的累积。

Based on the Biot＇s consolidation theory, a dynamic poro-elasto-plastic constitutive model for a sandy seabed with buried submarine pipeline was established to analyze the dynamic responses of a sandy seabed under the combined wave and current loading. The distribution of ex- cess pore pressure of seabed and wave pressure on the seabed surface were examined. The effects of different current velocities on the excess pore pressure under the combined wave and current loading were discussed. The numerical results show that the existence of current affects the wavelength and wave period of wave pressure on the seabed surface remarkably;the existence of submarine structure reduceds and slows down the excess pore pressure of seabed under pipelines.