Analysis of the Bearing Capacity of Press-in Pile with Installation Assistance into Stiff Ground

Press-in piling method enables displacement piles to be installed with little noise and vibration. Though installations into hard grounds require installation assistance such as water-jetting, augering, and rotary-cutting, the effect of these techniques on the bearing capacity has not been clear. This paper collects loading tests of steel pipe piles installed by the press-in piling with the assisted techniques and studies the axial performance. The test results of the load-settlement curves and unit resistances suggest that standard press-in and rotary cutting press-in pile have similar mechanisms with driven pile. Water-jetting decreases shaft resistance and varies base resistances, and the load-settlement curve resembles that of the bored pile. Finally, the estimated ultimate resistance coincides with the measured ones well, based on the proposed characteristic values. These results can supply basic information to design pile foundations with press-in piling.