基于m法的桥梁柔性群桩基础计算研究  

Research on the Calculation of Bridge Flexible Pile Group Foundation Based on M Method

作　　者：张华 ZHANG Hua(China Railway Fifth Survey and Design Institute Group Co.Ltd.,Beijing 102600,China)

机构地区：[1]中铁第五勘察设计院集团有限公司,北京102600

出　　处：《铁道建筑技术》2024年第10期138-141,192,共5页Railway Construction Technology

基　　金：中铁第五勘察设计院集团有限公司科技研发计划项目(T5Y2022-B03)。

摘　　要：桩基变形及内力计算是桩基力学检算的基础和依据。本文编制基于m法的柔性群桩基础变形和内力计算程序,并通过算例及第三方软件对程序准确性进行验证;对比铁路规范及公路规范对桩基计算结果的差异,并利用程序分析的便捷性探讨自由长度、比例系数等参数对桩基变形及内力的影响;研究桩基弯矩反弯点位置与自由长度、水平变形系数的相关性,并对桩基设计提出相关建议:(1)桩基自由长度会显著影响桩身内力,应注意考虑桩基自由长度准确性;(2)做好地质勘察,获取尽可能准确的各土层分类及对应的比例系数m值;(3)在土层含有软弱土或桩基自由长度较小的情况下,应考虑适当加长桩头非通长竖向钢筋。The pile foundation deformation and the internal force calculation are the foundation and basis of the mechanical calculation of the pile foundation.In this paper,a program for calculating the deformation and internal forces of a flexible pile group foundation based on the M method is compiled,and the accuracy of the program is verified by a case study and a third-party software.The differences between the calculation results of railway code and highway code on pile foundation are compared,and the influence of parameters such as free length and scale coefficient on pile deformation and internal force is discussed by using the convenience of program analysis,and the correlation between the position of the reverse bending point of pile moment and the free length and horizontal deformation coefficient of pile foundation is studied.In addition,relevant suggestions are proposed for pile foundation design work:(1)the free length of the pile foundation will significantly affect the internal force of the pile,and the accuracy of the free length of the pile foundation should be considered.(2)Do a good job of geological survey,and obtain the most accurate classification of each soil layer and the corresponding proportion coefficient M value.(3)When the soil layer contains weak soil or the free length of the pile foundation is small,the appropriate lengthening of the non full-length vertical steel bar of the pile head should be considered.

关 键 词：桥梁桩基 柔性群桩 程序 M法 内力变形 设计指导 

分 类 号：U443.15[建筑科学—桥梁与隧道工程]