Pile down-drag due to surface loading

摘要

Pile down-drag due to negative skin friction occurs as a result of downward movement of the soil relative to the pile. Relatively larger ground settlements may arise due to the consolidation of the soil as a result of surface loading, lowering of ground water table or the dissipation of excess pore water pressure generated during pile installation. This paper presents the results of down-drag loading experiments carried out on the centrifuge using extensively strain gauged closed-ended aluminium piles with pile stiffness equivalent to that of high quality concrete piles. The piles were installed by jacking into slightly over-consolidated kaolin clay. The down-drag resulted from the construction of a surface embankment around the piles. The experimental data are compared with predicted down-drag response obtained from finite element analysis. The pore pressure response and surface settlement of the clay stratum due to embankment construction are also presented.