粉质黏土中厚壁筒型基础减阻措施研究  

Resistance reduction measures for thick-walled bucket foundation in silty clay

作　　者：练继建[1] 赵昊 刘润[1] 郑宏杰 杨旭[1] LIAN Jijian;ZHAO Hao;LIU Run;ZHENG Hongjie;YANG Xu(State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300350,China)

机构地区：[1]天津大学水利工程仿真与安全国家重点实验室,天津300350

出　　处：《水力发电学报》2022年第9期108-117,共10页Journal of Hydroelectric Engineering

基　　金：青年科学基金项目(51709202);国家杰出青年科学基金项目(51825904)。

摘　　要：筒型基础具有建造成本低、安装效率高等优点,已在我国近海风场安装超60台。随着海上风电向深水化、大容量发展,筒型基础尺寸不断增大,岸边预制与浮运、沉放过程中钢制筒裙易发生屈曲破坏,导致安装失败。因此本文提出混凝土筒裙加钢制分舱板的厚壁筒型基础,在避免筒裙屈曲的同时进一步降低造价,但厚壁筒裙导致沉放阻力增加,有效的减阻措施及准确的沉放阻力预测是其安全沉放安装的关键。为此开展了粉质黏土中筒型基础室内模型沉放试验,探究了筒壁减阻环与筒端冲水破土装置的减阻效果,提出了考虑减阻效应的沉放阻力计算方法。研究结果表明,与分舱板等厚度的减阻环可使侧摩阻力减小约50%;筒端冲水破土装置可使端阻力减小约88%,为减小冲水破土对负压施加的影响,推荐采用冲水破土与负压沉放间隔作业的施工方式。Bucket foundation is an innovative type for supporting offshore wind turbines(OWT),and more than 60 foundations of this type have been installed in the wind farms in China due to its low cost and efficient installation.With the developing trend of large scale and deep water,the size of foundation grows,resulting in a high buckling failure probability of its steel bucket skirts during prefabrication,transportation and sinking.This paper develops a thick-walled bucket foundation that adopts a concrete skirt and steel bulkheads to further reduce its cost and skirt buckling possibility.However,as the penetration resistance of this foundation increases,how to reduce it becomes the key to successful installation.In this work,we conduct a laboratory test of the foundation in silty clay,and examine the resistance reduction effect of two measures:ring stiffeners and thick-skirt water flushing.And a calculation method of penetration resistance is developed to take the reduction effect into account.Results show that the ring stiffeners with the same size as the steel bulkheads can reduce the friction drag by 50%,and the flushing measure can reduce the end resistance by 88%.To avoid the influence on the suction operation caused by synchronous water flushing,an alternate operation of the two processes is suggested.

关 键 词：地基基础 海上风电 厚壁筒型基础 沉放阻力 减阻方法 

分 类 号：TU432[建筑科学—岩土工程]