静压沉桩挤土机理探讨及有限元分析  

Mechanism discussion and finite element analysis of soil-compacting by silent piling

作　　者：梅国雄[1] 宋林辉[1] 宰金珉[1] 周峰[1] 

机构地区：[1]南京工业大学土木工程学院,南京210009

出　　处：《计算力学学报》2008年第5期660-664,共5页Chinese Journal of Computational Mechanics

基　　金：国家自然科学基金(50608038);江苏省六大人才高峰项目基金(06-F-014);江苏省研究生创新基金(2007-128)资助项目

摘　　要：针对预制桩在静压沉桩过程中出现的挤土现象,从土体小主应力方向加载的角度考虑,视浅层土体的隆起为小主应力方向(水平向)加载引起大主应力(垂直向应力)增加所致。在已有的柱形小孔扩张理论基础上,通过引入考虑位移的土压力计算方法提出了桩周土体隆起分界面表达式。利用该表达式分析浅层土体的隆起量,并利用Randolph提出的深层土体径向位移解析公式给出深层土体的变形量。最后运用有限元数值模拟计算与本文的数值解答进行对比分析,结果相近。The problem that soil-compacting phenomena caused by silent piling is studied in this paper. The problem is composed of two parts： the heave of shallow soil and the radial displacement of deep soil. The heave problem is solved by use of the idea of loading at the minor principal （horizontal） stress direction, in which the mechanism of heave can be described as that the horizontal stress increment results in the vertical stress exceeding the gravity of soil. Based on the cavity expansion theory, the formula of heave interface is derived, in which the method of soil pressure considering displacement is employed. And the formula can be used to analyze the heave of shallow Soil. The expression developed by Randolph is employed to calculate the radial displacement of deep soil. The numerical analysis is performed to simulate the course of silent piling. And the numerical results show good agreement with the analytical solutions in this paper and the former researches, which adequately indicate that the application of loading at the minor principal stress direction to analyze the soil-compacting by silent piling is reasonable.

关 键 词：静压桩 挤土效应 小主应力 有限元分析 

分 类 号：TU473.13[建筑科学—结构工程]