摘要
海涂围垦形成的软黏土地基一般为欠固结土地基。为了研究垦区欠固结软黏土地基中的桩基负摩阻力规律,考虑不同桩周土初始含水率,以及自重固结和堆载2种工况,开展4组单桩模型试验,基于试验结果分析摩擦型管桩的桩土位移、桩身轴力、桩侧负摩阻力及中性点位置等特性。试验结果表明,不论在堆载还是自重固结条件下,随着桩周土含水率的提高,桩身沉降、土体沉降、桩身轴力及桩侧负摩阻力总体成增大趋势,桩周土初始含水率的降低引起的中性点位置的升高。在堆载条件下,中性点位置随着荷载等级的提高而下移;自重固结条件下,中性点位置随固结时间变化不大。在工程实际中,桩周土初始含水率的增加会扩大负摩阻力范围,增大负摩阻力峰值和桩身轴力,因此需要注意其对欠固结软黏土地基桩基负摩阻力的影响。
The soft clay foundation formed by tideland reclamation is generally unconsolidated.To study the behavior of negative skin friction of a pile in unconsolidated soft clay foundation,4 single-pile model tests were performed,in which different initial water contents of soft clay and two working conditions including self-weight consolidation and surcharge were considered.The characteristics of relative displacement between pile and soil,axial force of pile,negative skin friction and neutral plane position were investigated based on the test results.In both self-weight consolidation and surcharge conditions,the increase of the initial water content leads to the increase of pile settlement,clay settlement,axial force of pile and negative skin friction,and the decrease of the initial water content induces the rise of neutral plane position.In the condition of surcharge,the increase of vertical load leads to the drop of neutral plane position,while in the condition of self-weight consolidation the consolidation time has little effects on the position of neutral plane.In engineering practice,the initial water content of clay foundation should be pained attention since it would cause the increase of negative skin friction and pile axial force.
作者
谷川
王林伟
王军
张婷婷
蔡袁强
林刚
GU Chuan;WANG Linwei;WANG Jun;ZHANG Tingting;CAI Yuanqiang;LIN Gang(College of Civil Engineering and Architecture,Wenzhou University,Wenzhou,Zhejiang 325035,China;The Key Laboratory of Engineering and Technology for Soft Soil Foundation and Tideland Reclamation of Zhejiang Province,Wenzhou University,Wenzhou,Zhejiang 325035,China;School of Civil Engineering and Architecture,Wenzhou Polytechnic,Wenzhou,Zhejiang 325035,China;College of Civil Engineering,Zhejiang University of Technology,Hangzhou,Zhejiang 310014,China;Zhejiang Province Geological and Mineral Engineering Investigation Institute Co.,Ltd.,Hangzhou,Zhejiang 310012,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2022年第12期2554-2566,共13页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(52178349,51878513)。
关键词
桩基础
欠固结土
负摩阻力
模型试验
中性点
pile foundation
unconsolidated clay
negative skin friction
model test
neutral point
