复合桶形基础负压沉贯渗流特性研究  

Numerical study of seepage characteristics of composite suction caisson under suction installation

作　　者：徐成根 江海涛 徐孟涛 孙德成 吴新云 XU Cheng-gen;JIANG Hai-tao;XU Meng-tao;SUN De-cheng;WU Xin-yun(CGN Rudong Offshore Wind Power Co.,Ltd.,Nantong 226400,Jiangsu,China;College of Architecture and Civil Engineering,Zhejiang University,Hangzhou 310058,Zhejiang,China;Power China Huadong Engineering Co.,Ltd.,Hangzhou 311122,Zhejiang,China)

机构地区：[1]中广核如东海上风力发电有限公司,江苏南通226400 [2]浙江大学建筑工程学院,浙江杭州310058 [3]中国电建集团华东勘测设计研究院有限公司,浙江杭州311122

出　　处：《地基处理》2023年第2期126-132,共7页Journal of Ground Improvement

摘　　要：吸力桶基础由于其适用范围广泛、安装简单、可重复利用等优点,成为了海上风机基础的重要形式之一。本文结合江苏如东某海上风电复合桶形基础(多舱室吸力桶)的工程应用背景,在有限元软件COMSOL Multiphysics中采用线弹性土体模型建立复合桶形基础的负压沉贯模型。通过研究基础安装过程中土体渗流特征,发现复合桶内部土体受吸力影响较大,外部土体受影响较小,水头损失大部分发生于桶内,表现为桶内渗流梯度显著大于外部,因此渗流作用的存在使得复合桶壁沉贯阻力小于静压沉贯。复合桶和环形隔板侧壁孔隙水压力在靠近桶顶部时沿深度近似为线性变化,靠近端部则表现为明显的非线性,且端部处孔隙水压力不连续。通过与同主尺寸的单桶基础进行对比,发现环形隔板及肋隔板的存在阻碍了桶内负压向外部的传递,使得负压对于桶外部孔隙水压力的影响削弱,并抑制负压向更深海床处发展。The suction caisson foundation has become one of the important forms of offshore wind turbine foundation due to its wide range of application,simple installation and reusability.In this paper,combined with the engineering application of the offshore wind turbine supported by composite caisson foundation(multi-cabin suction caisson) in Rudong,Jiangsu,the finite element software COMSOL Multiphysics was used to establish a suction installation numerical model based on the linear elastic soil model.By studying the characteristics of soil seepage during foundation installation,it is found that the soil inside the composite caisson is greatly affected by suction than that outside the caisson.Most of the water head loss occurs inside the caisson,showing that the seepage gradient inside the caisson is significantly greater than that outside the caisson.Therefore,the skirt wall friction is less than jack installation.The pore water pressure around the skirt wall and the annular partition changes approximately linearly along the depth near the caisson lid.However,it shows obvious nonlinearity near the tip,where the pore water pressure is discontinuous.By comparing with the single caisson foundation of the same main size,it is found that the existence of the annular partition and the rib partition hinders the transmission of negative pressure inside the caisson to the outside.This weakens the effect of negative pressure on the pore water pressure outside the caisson,and inhibits the development of negative pressure to a deeper seabed.

关 键 词：复合桶形基础 负压作用 吸力安装 渗流场 孔隙水压力 海上风电 

分 类 号：TU47[建筑科学—结构工程]