Loading Sequence Effects on Dragload and Downdrag for Pile Foundation  

作　　者：孔纲强 杨庆 栾茂田 

机构地区：[1]State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology [2]Key Laboratory for Geomechanics and Embankment Engineering of Ministry of Education, Hohai University [3]Geotechnical Research Institute, Hohai University

出　　处：《Transactions of Tianjin University》2010年第3期203-208,共6页天津大学学报（英文版）

基　　金：Supported by National Natural Science Foundation of China (No.50679015);China Postdoctoral Science Foundation (No.20090461062)

摘　　要：Negative skin friction (NSF) is one of the important problems when designing a pile foundation. However, the influence of loading sequence on the dragload and downdrag for pile foundation is seldom studied. In this paper, a three-dimensional numerical model was established using FLAC3D. Compared with the results of model test, the established model could be used to study the NSF of pile foundation. The influencing factors were discussed including the length-diameter ratio of pile and the loading sequence of pile head load and surcharge. A case history was analyzed using FLAC3D. The calculated results are in good agreement with the measured results. It is concluded that the dragload and downdrag are remarkably influenced by the loading sequence of pile head load and surcharge. The dragload and downdrag reach the maximum values under the condition of surcharge after pile head load.Negative skin friction （NSF） is one of the important problems when designing a pile foundation. How- ever, the influence of loading sequence on the dragload and downdrag for pile foundation is seldom studied. In this paper, a three-dimensional numerical model was established using FLAC3D. Compared with the results of model test, the established model could be used to study the NSF of pile foundation. The influencing factors were discussed in- cluding the length-diameter ratio of pile and the loading sequence of pile head load and surcharge. A case history was analyzed using FLAC3D. The calculated results are in good agreement with the measured results. It is concluded that the dragload and downdrag are remarkably influenced by the loading sequence of pile head load and surcharge. The dragload and downdrag reach the maximum values under the condition of surcharge after pile head load.

关 键 词：pile foundation dragload downdrag negative skin friction load sequence numerical analysis 

分 类 号：TU473.1[建筑科学—结构工程]