A simplified method for progressive failures of piles in soft ground during rapid embankment construction

Abstract

A simplified method validated by centrifuge tests is developed to estimate both the deformation and stability of soft ground improved by piles during the rapid construction of embankments. Furthermore, this method, which considers pile-soil interaction, is adopted to investigate the failure mechanism and performance of piles. It is determined that piles embedded in a stiff stratum may be subjected to a dual bending failure. The first failure may occur at the soft-stiff interface because of the embedment effect of the stiff stratum, while the second failure may take place at the upper part of the piles due to the inflexion effect of soft ground movements. A progressive bending failure of piles may also occur as the maximum bending moment of each pile varies with the pile location. The progressive failure could propagate from the piles beneath the embankment toe towards the embankment centre. In addition, the location, stiffness, and fixity of piles have a significant influence on the stability of soft ground. The piles beneath the embankment toe are key piles, and increasing the stiffness and enhancing the embedment of these piles could efficiently ensure the stability of soft ground.