弹性或弹塑性土体中桩基的大变形分析  

Large Deformation Analysis for Piles on Elastic or Plastic Foundation

作　　者：胡育佳[1] 朱媛媛[2] 程昌钧[1] 

机构地区：[1]上海大学,上海200072 [2]上海师范大学,上海200234

出　　处：《应用力学学报》2008年第3期398-404,539,共7页Chinese Journal of Applied Mechanics

基　　金：上海市浦江人才计划项目(07pj14073);上海高校选拔培养优秀青年教师科研专项基金;上海市教委发展基金(05AZ15)

摘　　要：采用弧坐标,首先建立了位于弹性地基或弹塑性地基上并具有初始位移的桩基大变形行为的非线性微分方程组,并采用Winkeler模型来模拟地基对桩基的抗力;其次,应用微分求积方法离散非线性微分方程组,得到一组离散化的非线性代数方程,并给出了利用Newn-Raphson方法求解非线性代数方程的步骤;作为应用给出了数值算例,得到了桩顶受组合载荷作用时,变形后桩基的构形、弯矩和剪力,考察了土的弹性和弹塑性性质、桩基初始位移、荷载等参数对桩基力学行为的影响。最后将模型进行简化,得到了小变形理论的解析解,并比较了由大变形理论与小变形理论所得结果的差别。A set of nonlinear differential equations for nonlinear large deformation analysis of piles with initial displacements on an elastic foundation or a plastic foundation are presented by the arc-coordinate, where the Winkeler model is used to simulate the resistance of foundation to pile. The differential quadrature method (DQM) is applied to discretize the set of nonlinear equations, and the solving procedure is presented following Newton-Raphson scheme. The numerical examples show the configuration, bending moment and shear force of deformed piles subjected to combined loads. The effects of the elastic or plastic properties of soil, the initial displacement and loads on the mechanical behavior of piles are considered in detail. Then the analytical solution of a simplified model is obtained when the displacement is smaller, and the solutions obtained from both small deformation and large deformation theory are compared.

关 键 词：桩基 弧坐标 大变形 初始位移 微分求积法 参数研究 

分 类 号：O322[理学—一般力学与力学基础]