基于半解析半数值方法的高承台桩基础沉降计算

用半解析半数值方法计算层状弹性地基上高承台桩基础沉降的难点在于求解地基基本解。将基础和地基分成上下两个子结构：承台为上部子结构,下部子结构包括桩和地基。用轴对称有限元法,按照桩帽模型和圆筒模型考虑群桩的影响,可以非常方便地求出层状土中群桩顶作用荷载和桩的沉降之间的关系。以此作为下部子结构的基本解,推导出上下子结构相互作用的公式,从而对下部子结构不用划分单元,仅需对承台划分单元即可得到基础的沉降。这种分析方法,无需繁琐的公式推导,极大地减少了工作量,计算效率高,适用大型桩基础和超长桩研究。

Settlement Calculation of Pile Foundation with Elevated Cap by Semi-numerical and Semi-analytical Method

The difficulty of analyzing the settlements of pile foundation in layered foundation with elevated cap by using semi-analytical and semi-numerical(SASN) method is in getting the fundamental solution of soil,but this can be easily obtained by axisymmetric analysis with FEM.The model is divided into two parts: the upper part includes pier and abutment,the lower part include piles and foundation.The fundamental solution of lower part is solved by axisymmetric analysis with FEM,however,the upper part is modeled by solid elements,and so the governing equations of FEM can be formed and solved to get the settlement of pier on assumptions of vertical load are only the ones between the two parts.Application of axisymmetric analysis with FEM for solving fundamental solution of soil can make use of professional commercial finite element software,save research time,need no cumbersome formula and calculate with high efficiency.This method can also be used to analyze large-scale layered foundation.