桥梁基桩屈曲机理及其分析方法  

Reseachs of buckling mechanism and analytic methods of piles

作　　者：汪优[1] 赵明华[1] 黄靓[1] 

机构地区：[1]湖南大学土木工程学院,湖南长沙410082

出　　处：《中南公路工程》2005年第4期22-26,共5页Central South Highway Engineering

基　　金：国家自然科学基金项目(50378036)

摘　　要：讨论了基桩屈曲分析的现有方法,进而在分析基桩屈曲机理的基础上,将桩身视为考虑几何非线性的空间梁单元,利用更新的拉格朗日坐标体系建立有限元方程,并采用弧长控制法求解有限元非线性方程组,对基桩屈曲的几何非线性有限元分析进行了探讨。利用Matlab语言编制了相应的计算程序,以现场木桩压屈试验作为计算实例进行比较,计算表明,程序的计算结果吻合较好,可用于基桩屈曲的几何非线性分析。此外计算表明,地基系数对屈曲荷载的影响明显,随着地基系数的增大,基桩的屈曲荷载也随之增大。The analysis methods of buckling on piles are introduced briefly and the buckling mechanism of piles is analyzed. The shaft of a pile was regarded as the spatial beam element considered on the geometrical nonlinearity. The equation of the finite element was established by way of the updated Lagrangian formulation. And the buckling of arch structure was analyzed by arc-length method, which may solve the nonlinear equation of the finite element. Compared with the buckling experiment of woody piles in field, the calculation results approach the actual results and indicate that the procedure programmed by Matlab may appropriate for the buckling analysis of piles considered on the geometrical nonlinearity. Further more, soil resistance around piles is an important factor that affect the buckling load of piles based on plentiful computations and analysis.

关 键 词：基桩 屈曲 临界荷载 弧长控制法 

分 类 号：U443.15[建筑科学—桥梁与隧道工程]