复合桩基承台下土的极限承载力提高值分析  

Increment analysis of ultimate bearing capacity of soil under cap of composite pile foundation

作　　者：陈亚东[1,2] 王旭东[1] 宰金珉[1] 

机构地区：[1]南京工业大学土木工程学院,江苏南京210009 [2]淮阴工学院建筑工程学院,江苏淮安223001

出　　处：《南京工业大学学报（自然科学版）》2010年第3期35-38,共4页Journal of Nanjing Tech University(Natural Science Edition)

基　　金：国家自然科学基金资助项目(50678083)

摘　　要：为探究复合桩基承台下土体极限承载力提高值产生的根源,利用非线性有限元技术对常规桩筏基础(3D桩距)和复合桩基(6D桩距)进行三维弹塑性分析,得到土体绕桩滑动模式、土体极限承载力提高值等变化情况,并将数值计算的结果同提高值的理论解进行对比.分析结果表明:桩的遮拦作用使承台底土破坏时发生绕桩滑动并受到极限滑动阻力,从而提高了承台下土体的极限承载力;随着桩距的增大,承台下土体极限承载力提高的幅度和提高比例逐步下降,最后趋于天然地基的受荷特性.In order to study the source of the increment of ultimate bearing capacity of soil under cap of composite pile foundation,a finite element method was used to give a 3D elastoplastic finite element analysis to pile raft foundation of 3D and 6D pile diameter spacing.Slip pattern of soil around piles and the increment of ultimate bearing capacity of soil under cap were obtained from the analysis,the results were compared with analytic solutions.The study showed that the ultimate resistance to the soil sliding around pile shaft could enhance the ultimate bearing capacity of soil under the cap,the increment range and the proportion gradually decreases with the increase of the pile space from 3D to 6D,and bearing characteristic of soil under cap is gradually closer to the behavior of the nature ground.

关 键 词：桩基础 极限承载力 提高值 理论解 

分 类 号：TU473[建筑科学—结构工程]