软土地基松木桩挤土效应模拟的有限差分方法  

Fast lagrangian finite difference method for numerical simulation of compaction effect of soft soil foundation strengthened by pine piles

作　　者：燕柳斌[1] 胡李华[1] 苏国韶[1] 

机构地区：[1]广西大学土木建筑工程学院,广西南宁530004

出　　处：《广西大学学报（自然科学版）》2014年第4期794-801,共8页Journal of Guangxi University（Natural Science Edition）

基　　金：国家自然科学基金资助项目(51369007)

摘　　要：针对松木桩加固软土地基时软土出现非线性大变形且挤土效应难以精确预测的问题,基于圆孔扩张原理与FLAC3D计算程序,提出饱和软土中松木桩挤土效应模拟的快速拉格朗日有限差分法。单桩和群桩挤土效应的数值计算结果表明,该方法是可行的,计算精度明显高于经典的Vesic解析法,与模拟桩体贯入土体过程的挤土效应的有限元法相比较,具有实现容易、计算耗时较少且计算容易收敛等优点,克服了有限元法存在的桩土接触面力学参数获取困难、计算耗时大、三维群桩沉桩过程难以模拟等局限性,为软土地基松木桩加固工程的挤土效应合理预测提供了一种有效可行的实用技术手段。Nonlinear and prominent deformation of soil will occur and it is very difficult to accurately simulate soil compaction effect when pine piles are used to strengthen soft soil foundation. A fast la-grangian finite difference method based on cavity expansion theory and computer program FLAC3D is proposed to solve these problems. Both numerical results of single pile and grouped piles indicate that this method is rational and much more accurate than the classical analytical solution of Vesic. Compared with the finite element method that simulates the penetration of pile, the fast lagrangian fi-nite difference method has many advantages such as easy realization, less time consuming and fast convergence. The method can also overcome the shortages of the finite element method such as hard-ly obtaining parameters of pile-soil interface, hardly simulating grouped piles with three dimensional model and time-consuming. The proposed method can provide an effective and practical way to esti-mate the soil compaction effect of soft soil foundation strengthened by pine piles reasonably.

关 键 词：软土地基 松木桩 挤土效应 数值分析 

分 类 号：TU447[建筑科学—岩土工程]