基于承载特性的挤扩支盘桩加固深厚软基作用机理研究  

Mechanism of reinforcement of squeezed branch piles for deep soft foundation based on load bearing capacities

作　　者：张坤标 汪益敏[1] 陈页开[1] 丘燊 易浩 曾昭宇 ZHANG Kunbiao;WANG Yimin;CHEN Yekai;QIU Shen;YI Hao;ZENG Zhaoyu(School of Civil Engineering and Transportation,South China University of Technology,Guangzhou 510641,China;Guangdong Communication Planning&Design Institute Group Company,Guangzhou 510440,China;Guangdong Transportation Construction Engineering Quality Inspection Center,Guangzhou 510420,China)

机构地区：[1]华南理工大学土木与交通学院,广东广州510641 [2]广东省交通规划设计研究院集团股份有限公司,广东广州510440 [3]广东省交通运输建设工程质量检测中心,广东广州510420

出　　处：《岩土工程学报》2024年第S02期97-102,共6页Chinese Journal of Geotechnical Engineering

基　　金：2021年度交通运输行业重点科技项目(2021-MS1-022)。

摘　　要：针对深厚软土地基中挤扩支盘桩布置,结合汕头软基区挤扩支盘桩应用工程的单桩静载试验建立三维数值模型,探究了支盘桩在沉降过程中的荷载分担特点和盘-土相互作用机制。结果表明:未贯穿深厚软基的挤扩支盘桩桩端的荷载分担率远低于等截面直孔桩;挤扩支盘桩群桩效应系数η_(g)与桩体数目N和桩间距Sp密切相关,推荐桩间距S_(p)=8d为深厚软基区支盘桩的最优间距;支盘端部尤其下部支盘端部在极限沉降状态下分担大量荷载至盘周土体,盘净距S_(b)通过改变支盘结构持力土层性质而影响基桩承载能力。To address the layout of squeezed branch(SB)piles in deep soft soil,a 3D numerical model is established based on the single pile static load tests on the SB pile application project in Shantou soft soil area.The load sharing characteristics and the branch-soil interaction mechanism are investigated during the settlement development.The results show that the load sharing ratio at the pile tip of the SB piles that do not penetrate through deep soft foundation is 19.6%,significantly lower than that of straight piles.The group efficiencyη_(g) of the SB piles is correlated to the number of piles N and pile spacing S_(p),with an optimal spacing of 8d recommended for the SB piles in deep soft soil regions.The tip of branch,particularly the lower branch,can transfer a considerable load to the surrounding soil under the ultimate settlement conditions.The inter-branch spacing Sb affects the load bearing of piles by altering the properties of soil stratum of branches.

关 键 词：挤扩支盘桩 承载特性 数值模拟 荷载传递 软土地基处理 

分 类 号：TU473[建筑科学—结构工程]