摘要
基于荷载传递法,建立了热力耦合作用下能量桩单桩工作特性的简化分析方法。该方法中将桩-土荷载传递函数取为双曲线,采用曼辛法则模拟温度循环过程中桩-土界面的卸载和再加载特性,通过再加载过程中刚度的折减近似考虑塑性变形的积累。利用矩阵位移法求解控制方程组后可直接得到任意温度-力学组合作用下的桩体变形、桩身轴力、桩侧阻力和桩端阻力,无需事先假设温度位移零点的位置。通过与试验数据的对比分析,验证了所提方法的可靠性。结合算例,研究了能量桩的长期工作特性。结果表明,温度循环会造成自由桩的桩顶沉降增加,固定桩的桩顶应力减小,温度循环的影响与桩顶静力荷载水平和土体刚度的衰减程度密切相关。
A simplified method based on the load transfer approach is proposed for the working performance analysis of single energy piles. In the method, the load transfer function is chosen as a hyperbolic curve, and the unloading and reloading characteristics of pile-soil interface during temperature cycling are simulated by Masing’s criterion. The accumulation of plastic deformation is approximated by reduction of stiffness during reloading. The location of the null point can be naturally determined by solving the governing equations through the matrix displacement method. The pile displacement, the axial force, the shaft resistance, and the base resistance can also be obtained. The proposed method is validated by comparing the predicted values with the experimental data collected from literatures. Finally, the long-term performance of single energy piles is studied with an example. The computed results indicate that the thermal cycles increase the settlement of free pile top and decrease the stress of fixed pile top. The influence of the thermal cyclic loading is related to the static load level and the degree of the stiffness degradation of the surrounding soil.
作者
费康
戴迪
洪伟
FEI Kang;DAI Di;HONG Wei(Institute of Geotechnical Engineering,Yangzhou University,Yangzhou,Jiangsu 225127,China;Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing,Jiangsu 210098,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2019年第1期70-80,90,共12页
Rock and Soil Mechanics
基金
国家自然科学基金资助项目(No.51778557)
江苏省"青蓝工程"(苏教师[2016]15号)~~
关键词
能量桩
荷载传递法
温度循环
残余沉降
热应力
energy pile
load transfer approach
thermal cycles
irreversible settlement
thermal stress
