考虑基桩自重作用的桩身轴力计算方法及其应用研究  

A New Calculation Method for Pile Axle Force Considering Pile’s Weight and Application Research

作　　者：陈锋 张飞 叶阳升 陈晓斌[2,4] 杨严龙 蔡德钩 

机构地区：[1]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081 [2]中南大学土木工程学院,湖南长沙410083 [3]中国铁道科学研究院集团有限公司,北京100081 [4]中南大学重载铁路工程结构教育部重点实验室,湖南长沙410083

出　　处：《铁道建筑》2019年第12期79-84,共6页Railway Engineering

基　　金：国家自然科学基金(51678575);中国铁路总公司科技研究开发计划(2017G008-A)

摘　　要：通过考虑基桩自重影响,改进了基于佐藤悟双折线模型,提出一种考虑基桩自重的轴力改进计算方法,首先修正可以考虑基桩自重的荷载传递微分方程,推导出适用于任意桩周土体沉降曲线的桩侧摩阻力解析解;然后引入荷载作用下土体沉降弹性解,改进佐藤悟双折线桩侧摩阻力应力传递函数,进而提出可以考虑基桩自重的桩身轴力计算公式。同时,结合太焦(太原-焦作)高速铁路CFG桩工程实践进行CFG桩侧摩阻力现场原位测试试验,开展考虑基桩自重影响的桩身轴力计算方法应用研究;通过桩身轴力与侧摩阻力实测结果、未考虑自重的计算结果和考虑自重改进后的计算结果之间对比分析,论证考虑基桩自重作用的桩身轴力计算方法可行性。应用结果表明:改进后的计算结果与工程实测结果更加吻合,考虑基桩自重的桩身轴力计算方法可以获得更高的计算精度。This paper studies the improvement calculation method of pile axle force based on Kezdi’s double-broken-line model and considering the influence of the pile’s weight.Firstly,the differential equation of load transfer is modified under the condition of the pile’s weight,and the analytical solution of pile lateral friction suitable for the settlement curve of any pile surrounding soil is derived.Furthermore,the elastic solution of soil settlement under uniform load is introduced to improve the lateral friction stress transfer function of Kezdi’s double-broken-line model,and the calculation equation of pile axle force considering pile’s weight is put forward.Meanwhile,based on the field in-situ test of pile lateral friction of the CFG pile of the Taiyuan-Jiaozuo high speed railway,the application research on the improvement calculation method of pile axle force considering the influence of the pile’s weight is carried out.The measured results,the unmodified calculation results,and the improved calculation results are compared and analyzed.The comparison results show that the improved calculation results are more consistent with the measured results,which proves that it is feasible to modify the pile lateral friction calculation by introducing the pile’s weight.

关 键 词：基桩自重 桩侧摩阻力 荷载传递法 桩-土相互作用 应力传递函数 

分 类 号：TU473.1[建筑科学—结构工程]