考虑不同灌浆效果的海上风电顶部灌浆桩基础竖向抗拔承载力数值研究  

Numerical study on vertical uplift bearing capacity of offshore top grouted pile foundation considering different grouting effects

作　　者：宋俊霖 朱文轩 SONG Junlin;ZHU Wenxuan(State Key Laboratory of Ocean Engineering.,Shanghai Jiao Tong University,Shanghai 200240,China;Department of Civil Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学海洋工程国家重点实验室,上海200240 [2]上海交通大学土木工程系,上海200240

出　　处：《甘肃科学学报》2024年第2期50-58,共9页Journal of Gansu Sciences

基　　金：国家自然科学基金项目(42207220);上海市浦江人才计划项目(22PJ1408800)。

摘　　要：海上风电大直径钢管桩与导管架常用灌浆连接形成闭口桩,而现有闭口桩设计不考虑或是低估了灌浆段的承载力贡献,而且施工的不确定性可能导致灌浆体深度不足或是渗透性过大,因此研究不同灌浆效果对承载力的影响可为闭口桩设计提供参考。通过岩土数值软件ABAQUS设置水单元及调整灌浆段渗透性等方式模拟不同灌浆效果,并进行影响因素分析。模型采用修正剑桥本构,考虑黏土地层并引入黏结接触模拟灌浆段底部与土体的相互作用。结果表明,不同灌浆效果的荷载-位移曲线均存在明显拐点,灌浆不足和灌浆正常两种工况下的极限抗拔承载力基本一致,灌浆段的承载力分担比约占14.4%;而灌浆渗漏的极限抗拔承载力相比则存在明显差距,其主要来源于灌浆段部分。竖向抗拔承载力的影响因素分析结果表明,随着接触面刚度系数的增大,抗拔承载力也随之增大;随着长径比增大,抗拔承载力逐渐减小;桩壁厚度的影响并不能单纯以桩体内外径尺寸来评判。The large-diameter steel pipe piles of offshore wind power are commonly connected to the jacket through grouting to form closed end piles,while the existing design of uplift piles does not consider or underestimates the bearing capacity contribution of the grouting section.Moreover,the uncertainty of construction may lead to insufficient depth or excessive permeability of the grouting body.Therefore,studying the impact of different grouting effects on bearing capacity can provide reference for design.In this paper,ABAQUS is used to simulate different grouting effects by setting water units and adjusting the permeability of the grouting section,and the influencing factors are analyzed.The model adopts a modified Cambridge constitutive model,considering the clay layer and introducing adhesive contact to simulate the interaction between the bottom of the grouting section and the soil.The results show that there are significant inflection points in the load-displacement curves for different grouting effects,and the ultimate uplift bearing capacity under both insufficient and normal grouting conditions is basically the same.The bearing capacity sharing ratio of the grouting section is about 14.4%.However,there is a significant difference in the ultimate uplift bearing capacity of grouting leakage,mainly from the grouting section.According to the analysis results of the influencing factors of the vertical uplift bearing capacity,as the stiffness coefficient of the contact surface increases,the uplift bearing capacity also increases;with the increase of the aspect ratio,the uplift bearing capacity gradually decreases;the influence of pile wall thickness cannot be judged solely by the external diameter of the pile body.

关 键 词：海上风电 灌浆效果 顶部灌浆桩基础 黏结接触 抗拔承载力 分担比 

分 类 号：TU47[建筑科学—结构工程]