水平循环荷载作用下单桩竖向位移试验研究  

Experimental study on vertical displacement of single pile under horizontal cyclic load

作　　者：郭景琢 马庆伟 李钟顺 周强 Guo Jingzhuo;Ma Qingwei;Li Zhongshun;Zhou Qiang(China Construction Infrastructure Co.Ltd,Beijing 100089,China)

机构地区：[1]中国建设基础设施有限公司,北京100089

出　　处：《建筑科学》2025年第1期47-56,共10页Building Science

摘　　要：桩基础作为支撑建筑物的基本构件,在砂土地基工程建设中得到广泛的应用。本研究旨在深入探讨水平循环荷载作用下单桩的竖向位移、桩侧摩阻力及桩端力的变化规律,以填补现有研究中对该方面的不足与欠缺。传统的研究主要关注水平循环荷载对桩-土响应的影响,而忽略了桩在这种荷载作用下的竖向位移。为了实现这一目标,本研究通过室内模型及离心机模型试验,分别研究了水平循环荷载作用下砂土中单桩竖向位移、桩端阻力的变化规律。利用数字图像DIC技术对桩体的竖向位移进行了测量。试验结果表明,在水平循环荷载作用下,砂土中的桩体产生了一定程度的沉降。随着桩顶竖向荷载或水平循环位移幅值的增大,桩端力及桩体沉降也逐渐增大。产生了由背土侧桩侧摩阻力的丢失及不平衡力的传递导致的试验现象,端承桩相比摩擦桩更能降低受水平往复荷载作用的桩体沉降。本文总结了室内模型及离心机模型试验结果,探讨和阐明了不同循环水平荷载作用下桩的竖向运动机理,为循环荷载作用下的桩基础沉降提供了有益的参考依据。研究成果表明了现行桩基、地基设计规范对水平循环荷载下桩竖向位移的不足,并建议对相关规范进行修订。这项研究为提高桩基础设计的安全性和可靠性提供了重要的工程指导。As a basic component of supporting buildings,pile foundation is widely used in the construction of sandy soil foundation.The purpose of this study is to investigate the vertical displacement of single pile,pile side friction resistance and pile end force under horizontal cyclic load,so as to fill the shortcomings of the existing researches in this aspect.Traditional studies mainly focus on the effect of horizontal cyclic loads on pile-soil response,but ignore the vertical displacement of piles under such loads.In order to achieve this goal,this paper studies the change law of vertical displacement and tip resistance of single pile in sand under horizontal cyclic load through laboratory model and centrifuge model test.The vertical displacement of pile is measured by digital image DIC technique.The test results show that the pile in sand has a certain degree of settlement under the horizontal cyclic load.With the increase of pile top vertical load or horizontal cyclic displacement amplitude,pile end force and pile settlement also increase gradually.It is a test phenomenon caused by the loss of side friction resistance and the transfer of unbalanced force of the pile on the back side of the soil.The end bearing pile can reduce the pile settlement under horizontal reciprocating load more than the friction pile.This paper summarizes the test results,discusses and clarifies the vertical motion mechanism of pile under cyclic horizontal load,and provides a reference for the settlement of pile foundation under cyclic load.The research results emphasize the inadequacy of the current design code of pile foundation and foundation to the vertical displacement of pile under horizontal cyclic load,and call for revision of the relevant code.This study provides important engineering guidance for improving the safety and reliability of pile foundation design.

关 键 词：桩基础 水平循环荷载 沉降 砂土 侧摩擦阻力丢失 不平衡力 

分 类 号：TU753.3[建筑科学—建筑技术科学]