摘要
软土地层中当桩顶水平荷载较大时,采用传统m法计算容易低估桩身弯矩与挠曲变形,有必要针对该问题提出相关计算方法。将地基土体简化为理想弹塑性体,假定桩身某一深度处存在土体的弹塑性变形临界点,临界点以上的土体进入塑性变形状态,而临界点以下的土体仍处于弹性变形状态,分段建立桩身挠曲微分控制方程,得到水平受荷单桩简明弹塑性计算方法。现场单桩实测和参数敏感性分析结果表明:采用简明弹塑性计算方法得到的桩身最大弯矩较传统m法计算精度提高38.1%;桩身最大水平位移计算精度提高22.3%;桩顶边界条件对桩身水平位移与弯矩沿桩身的分布规律影响显著;桩身最大弯矩和水平位移对土体的极限抗力系数及其形状参数较敏感,设计中宜按下限值选取。
When the top of a pile in soft ground is subjected to a large horizontal load,the traditional m method would underestimate the bending moment and deformation of the pile element.Therefore,it is necessary to propose relevant calculation methods for this problem.Simplifying the soft ground to an ideal elastoplastic body,and assume that there exists a critical point at a certain depth of the ground where the soil mass above the critical point behaves plastically and the soil mass below the point behaves elastically.The deflection differential control equation of the pile is established and a simplified elastoplastic calculation method for the horizontally loaded single pile is proposed.The results of field measurements and parametric study show that the maximum bending moment calculated by the simplified elastoplastic calculation method is 38.1%more accurate to field measurement in comparison with the traditional m method,and the calculation accuracy of the maximum horizontal displacement of the pile is improved by 22.3%.It indicates that the boundary conditions at pile top have significant impact on the distribution of lateral deflection and bending moment along the pile.Moreover,parameters of soil limit resistance and soil shape have remarkable influence on the maximum bending moment and lateral deflection and it is recommended to choose the lower values in pile design.
作者
邓涛
林聪煜
柳志鹏
黄明
陈文菁
DENG Tao;LIN Cong-yu;LIU Zhi-peng;HUANG Ming;CHEN Wen-jing(College of Civil Engineering,Fuzhou University,Fuzhou,Fujian 350108,China;Fujian Provincial Key Laboratory on Multi-Disasters Prevention and Mitigation in Civil Engineering,Fuzhou,Fujian 350108,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2020年第1期95-102,共8页
Rock and Soil Mechanics
基金
国家自然科学基金（No.41672290）
福建省自然科学基金（No.2016J01189）~~
关键词
桩基工程
水平受荷桩
大位移
简明弹塑性计算方法
M法
pile foundations
laterally loaded pile
large displacement
simplified elastoplastic calculation method
m-method
