砂土地层桩基自平衡解析转换方法及承载力研究  

Research on Self-Equilibrium Analytical Conversion Method and Bearing Capacity of Pile Foundation in Sandy Soil Stratum

作　　者：李奕金 LI Yijin(China Civil Engineering Construction Corporation,Beijing 100038,China)

机构地区：[1]中国土木工程集团有限公司,北京100038

出　　处：《铁道建筑技术》2024年第11期66-69,92,共5页Railway Construction Technology

基　　金：中国土木工程集团有限公司科研计划课题(ZT-2023B03)。

摘　　要：单桩承载力的确定是桥梁桩基础设计至关重要的一个环节,本文基于桥梁试验桩自平衡现场测试结果并结合该项目地区特点,提出砂土地区自平衡试验荷载—沉降量曲线向传统静载试验解析转化方法。结果表明:试验桩的上段桩和下段桩曲线均为缓变形曲线型态;将自平衡试验结果向传统静载试验进行转换计算,转换后的Q~s曲线没有出现明显的向下弯折段和第二拐点,说明三根试验桩的承载力存在一定的富余;三根试验桩均为受压状态,试验桩轴力梯度大位置,桩侧摩阻力大,沿着桩基深度的方向,桩身轴力和侧摩阻力呈现先增大后减小的趋势;对于同一根试验桩基,随着试验荷载的增大,试验桩同一桩深处桩身轴力和侧摩阻力随之增大。The determination of the bearing capacity of a single pile is a crucial step in the design of bridge pile foundations.Based on the results of self-balancing field tests of bridge test piles and combined with the characteristics of the project area,this article proposes a method for the analytical transformation of load settlement curves from self-balancing tests in sandy soil areas to traditional static load tests.The results show that:the curves of the upper and lower sections of the test pile are both in the form of slow deformation curves.The results of the self-balancing test were converted to traditional static load tests for calculation.The converted Q~s curve did not show any obvious downward bending section or second inflection point,indicating that there is a certain surplus in the bearing capacity of the three test piles.The three test piles are all in a compressed state,depth of the pile foundation,the axial force and lateral friction resistance of the pile body show a trend of first increasing and then decreasing.For the same test pile foundation,as the test load increases,the axial force and lateral friction resistance of the pile body at the same depth of the test pile also increase.

关 键 词：桥梁桩基 自平衡法 试验桩 承载特性 

分 类 号：U443.15[建筑科学—桥梁与隧道工程]