成层地基中倾斜受荷群桩的非线性有限元分析  

Nonlinear finite element analysis of pile group under inclined loads in stratified subgrade

作　　者：邹新军[1] 赵明华[1] 邬宝林 

机构地区：[1]湖南大学岩土工程研究所,湖南长沙410082 [2]深圳市勘察测绘院,广东深圳518028

出　　处：《中南大学学报（自然科学版）》2006年第4期820-825,共6页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(50378036)

摘　　要：针对轴、横向荷载共同作用或倾斜荷载作用下群桩基础受力问题的复杂性,引入无厚度型接触面单元和“无拉力”分析方法,采用非线性有限元法对倾斜受荷群桩的受力变形特性进行探讨,开发考虑材料非线性、桩-土-承台共同工作机理、桩周地基土体的分层性及不同桩顶荷载形式等因素的计算程序,并由此讨论初始应力场及桩顶荷载大小、倾角变化对桩身内弯矩与轴力分布的影响曲线。研究结果表明:刚性承台顶的荷载不变而倾角增大时,中桩桩顶的弯矩逐渐增加,边桩的弯矩则逐渐减小;当荷载倾角不变而荷载增加时,承台下各基桩的弯矩变化规律则随荷载倾角的不同而变化。Considering the complex behavior of pile group foundation lateral loads or inclined loads, no-thickness interface element （i. e. and no-tension force method were both introduced in the nonlinear under simultaneous Goodman interface element analysis of axial and element） the inner forces and flexural deflection along the pile shaft under inclined loads. And a program was worked out as well, in which the material nonlinearity, pile-soil-pile cap interaction mechanism, stratified structure of the subsoil and various kinds of pile top loads were taken into account. Based on the present method and calculation program, influencing curves in the initial stress field, pile top loads and inclination angles on the distribution of moment and axial force along the pile shaft were discussed and obtained, respectively. The results show that, if the loads on stiff pile cap keep constant while the inclination angles increase, the bending moment of middle pile top and side pile top will increase and diminish, respectively. On the contrary, if the inclination angles keep constant while the loads increase, the bending moment of various piles under the stiff cap will change with the inclination angle and differ from each other.

关 键 词：群桩基础 倾斜荷载 成层地基 非线性有限元法 

分 类 号：TU473.1[建筑科学—结构工程]