3D Numerical Modeling of a Piled Embankment under Cyclic Loading

Abstract

Embankments over pile-reinforced soft soil (called piled embankments) are known as one of the interesting techniques for soft soil improvement. They have been broadly applied in infrastructure projects thanks to their advantages, such as the decrease in settlement, the reduction in construction time, and the reasonable cost. The shearing and the soil-arching mechanisms within embankments result in an increase of the stress acting on the pile head and a reduction of the soft soil pressure. They can reduce the total and differential settlements. Numerous studies were carried out to better understand the behavior of this technique. However, most of the research focused on static loadings, and few studies concerning the cyclic loading were conducted. The aim of this study was to investigate the behavior of a piled embankment subjected to different traffic cyclic loadings. A three-dimensional numerical modeling using the finite-element method (FEM) was conducted with the use of Abaqus. An advanced constitutive soil model based on the hypoplasticity concept was used for granular soil and compared with the conventional one (a linear elastic-perfectly plastic model with the Mohr-Coulomb failure criterion) for aspects of static and cyclic loading. A high number of load cycles applied to a piled embankment was also considered in the study. The numerical results show that the hypoplastic model is better than the linear elastic-perfectly plastic model to deal with the soil-arching decrease and cumulative settlements under cyclic loading. In addition, the influence of the number of traffic load cycles, the vehicle speed, and the embankment height on the arching effect and the cumulative settlements is presented.