Semianalytical Solutions for Abutment Piles Under Combined Active and Passive Loading

Abstract

Abutment piles in soft ground are always subjected to both active loads from upper structures and passive loads from horizontal soft ground displacements; however, theoretical solutions for abutment piles under such combined loads are limited in the available literature. A growth model for the load transfer between the moving soil and piles was proposed to determine the lateral passive loads acting on abutment piles induced by the approach embankments, based on the plastic deformation theory. By using the transfer matrix method, semianalytical solutions for active–passive coupled loading piles in layered soils were presented, in which the elastoplastic soil model was used and the effects of vertical forces on the lateral responses of abutment piles caused by passive loading were considered. The validity of the proposed solution was validated by comparing with measurements from centrifuge tests and predictions from other two existing methods. The influence of the soil resistance and the distribution of axial forces along the pile were also investigated. The performance of abutment piles will be significantly improved as soft soil resistance is increased. The distribution of axial load along the pile has no significant effect on the response of abutment piles and can be simplified as a constant with the value equal to the vertical load acting on the pile head.