Three-Dimensional Numerical Modeling of a Piled Embankment

Abstract

This paper proposes a three-dimensional numerical modeling of an embankment over a soft ground mass improved by vertical stiff piles, using a finite-difference continuum approach (FLAC3D). Arching occurs in the embankment granular material, leading to load transfer onto the piles and surface settlement reduction and homogenization. The embankment, the piles, and the soft ground are explicitly taken into account in the proposed numerical model. First, a unit cell from the pile grid is considered. Two sorts of soft clay deposits and two embankment materials are successively modeled. The soft soil behavior is simulated by the modified Cam Clay model and the embankment material behavior is successively simulated by an elastic perfectly plastic model with a Mohr–Coulomb failure criterion and then by an isotropic hardening elastoplastic model, the CJS2 model, in order to approach the real system behavior. The calculations are performed in drained conditions, simulating the long-term behavior. The impact of the soft soil deposit compressibility and of the embankment material characteristics are underlined. The academic case of a current embankment section including lateral slopes is then simulated. The embankment is