Experimental Investigation of Soil-Arching Development in Unreinforced and Geosynthetic-Reinforced Pile-Supported Embankments

Soil arching is one of the most important mechanisms in piled embankments. To investigate the development of soil arching in piled embankments, 14 unreinforced and 8 geosynthetic-reinforced model tests were carried out using a two-dimensional (2D) multitrapdoor test setup with analogical soil. This study revealed that basal geosynthetic reinforcement changed the three deformation patterns into two development patterns with concentric elliptical arches under the same conditions. The stress reduction ratios (defined as the ratio of the average pressure on the trapdoor at a certain settlement to the initial pressure on the trapdoor at zero settlement) corresponding to the three deformation patterns in the unreinforced tests were distinctively different. The change of the stress reduction ratio during the settlement of the subsoil also showed how basal reinforcement affected soil arching in piled embankments. The geosynthetic with lower tensile stiffness resulted in more soil arching than that with higher tensile stiffness. (C) 2018 American Society of Civil Engineers.