桩身变截面效应对异型摩擦桩承载性能的影响分析  

Analysis of the influence of variable cross-section effect on the bearing performance of special-shaped piles

作　　者：张哲伦 陈海兵 俞峰[1] 陈鑫 ZHANG Zhelun;CHEN Haibing;YU Feng;CHEN Xin(School of Civil Engineering and Architecture,Zhejiang Sci-Tech University,Hangzhou 310018,China)

机构地区：[1]浙江理工大学建筑工程学院,杭州310018

出　　处：《浙江理工大学学报（自然科学版）》2023年第5期651-663,共13页Journal of Zhejiang Sci-Tech University(Natural Sciences)

基　　金：浙江省自然科学基金探索项目(LQ20E080018)。

摘　　要：变截面异型桩沿桩身每隔一定距离设置一个变截面环段,通过独特的桩土相互作用,在提升桩侧阻力的同时,充分发挥了桩身的结构强度。为了研究变截面效应对变截面异型桩承载性能的影响,采用有限元方法分析了变截面环数、变截面段直径对变截面异型桩桩周土体位移场、桩身轴力、桩段侧摩阻力的影响;采用规范经验公式和有限元计算的方法,对比不同土质条件下变截面效应对桩的竖向极限抗压承载力的影响。结果表明:当变截面异型桩竖向受荷时,桩周土的破坏形式由变截面环区域的局部破坏,逐渐转变为沿着桩变截面外径的整体剪切破坏;优化变截面的环数可提升变截面异型桩的竖向抗压承载力。变截面异型桩的桩身轴力和桩侧阻力的整体分布趋势同普通管桩一致,变截面段轴力和侧摩阻力远大于非变截面段,且桩身强度优势得到充分发挥。经规范经验公式计算得到的变截面异型桩极限抗压承载力,较数值计算结果偏于保守。该研究为变截面异型桩承载性能的理论分析和试验研究提供思路,同时为工程实际有效应用变截面异型桩提供参考。The variable cross-section pile is set with a variable cross-section ring at a certain distance along the pile body.Through the unique pile-soil interaction,it not only improves the shaft resistance of the pile,but also exerts the characteristics of the structural strength of the pile body.To study the influence of the variable cross-section effect on the bearing capacity of variable cross-section special-shaped piles,the finite element method was used to analyze the influence of variable cross-section ring number and variable cross-section diameter on the soil displacement field around the variable cross-section pile,the axial force of pile body and the shaft resistance of the pile section;the influence of the variable cross-section effect on the vertical ultimate compressive bearing capacity of piles under different soil conditions was compared by using the empirical formula and the finite element method.The results show that when the variable cross-section special-shaped pile is loaded vertically,the failure mode of the soil around the pile changes from local failure in the variable cross-section ring area to overall shear failure along the outer diameter of the variable cross-section pile,and the vertical compressive bearing capacity of the variable cross-section pile can be improved by optimizeing the ring number of the variable section.The overall distribution trend of the axial force and shaft resistance of the variable cross-section special-shaped pile is consistent with that of ordinary pipe piles,the axial force and shaft resistance of the variable section are far greater than those of non-variable sections,and the pile strength is fully exerted.The ultimate compressive bearing capacity of variable cross-section special-shaped piles calculated by the empirical formula is conservative compared with the numerical calculation results.This study provides ideas for the theoretical and experimental study of the bearing capacity of variable cross-section special-shaped piles,and provides reference for their ef

关 键 词：变截面效应 异型摩擦桩 承载性能 位移场 桩型参数 有限元方法 

分 类 号：TU473.1[建筑科学—结构工程]