砂土地区超长基桩双荷载箱法承载特性试验研究  

Experimental study on bearing characteristics of super-long foundation piles in sandy soil area using the double-load box method

作　　者：陈维超 杨伟军[2] 陈浩 杨建宇[2] CHEN Weichao;YANG Weijun;CHEN Hao;YANG Jianyu(Hunan No.4 Engineering Co.,Ltd.,Changsha 410119,China;Changsha University of Science&Technology,Changsha 410114,China;Hunan Construction Engineering Group Co.,Ltd.,Changsha 410004,China)

机构地区：[1]湖南省第四工程有限公司,湖南长沙410119 [2]长沙理工大学,湖南长沙410114 [3]湖南建工集团有限公司,湖南长沙410004

出　　处：《铁道科学与工程学报》2021年第5期1143-1154,共12页Journal of Railway Science and Engineering

基　　金：湖南省自然科学基金资助项目(2015JJ4106);长沙理工大学桥梁工程湖南省普通高校重点试验室开放基金资助项目(10KA01);湖南建工集团科技计划项目(JGJTK2014-008)。

摘　　要：依托越南砂土地区某工程超长基桩,采用双荷载箱法进行原位承载力试验,研究砂土地区超长基桩的荷载位移曲线、桩身压缩、桩身轴力传递、桩土相对位移、桩侧及桩端摩阻力分布等承载特性。研究结果表明:荷载箱附近土体表现出典型弹塑性体特征,靠近荷载箱的土体先出现桩土相对位移,其位移量最大,土体侧摩阻力优先发挥;离荷载箱越远,土体侧摩阻力发挥越晚,达到极限状态之前桩侧摩阻力与位移曲线呈线性关系;桩端阻力-位移曲线呈现出典型的两阶段特性,加载前期迅速上升,随后随桩端位移线性增长;该地区基桩密实砂层转换系数推算在0.6~0.7之间,略低于国内常用值。本文的研究方法和结果可为类似条件砂土地区超长基桩的承载特性研究提供参考。Based on the super-long foundation pile in the sandy soil area of Vietnam,the in-situ bearing capacity test was carried out by using the double load box method.The bearing characteristics of the overlength foundation pile in such areas,such as load-displacement curve,compression of pile body,axial force transfer of pile body,the relative displacement of pile and soil,distribution of skin friction at pile side and pile end,were investigated.The results are drawn as follows.The soil near the loading box exhibits the characteristics of typical elasto-plasticity,and the relative displacement between the pile and soil occurred foremostly with the largest displacement.In the meantime,the lateral friction resistance of the soil body works in priority,there displays a linear relationship between the friction resistance of the pile side and the displacement curve before reaching the limit state.The resistance-displacement curve of the pile tip exhibits a typical two-stage characteristic,which rises rapidly in the early stage of loading and then increases linearly with the pile tip displacement.The conversion coefficient of dense sand layer of foundation pile is between 0.6 and 0.7,which is slightly lower than the commonly value used in China.The research methods and results in this paper can provide a reference for the study of the bearing characteristics of the super-long foundation pile in sandy areas with similar conditions.

关 键 词：砂土地区 超长基桩 双荷载箱 承载特性 

分 类 号：TU473.11[建筑科学—结构工程]