Nonlinear analysis of infinite beams on granular bed-stone column-reinforced earth beds under moving loads

Abstract

The present paper pertains to the modeling and the analysis of an infinite beam subjected to a concentrated load moving at a constant velocity and resting on granular bed-stone column-reinforced earth beds. The granular fill has been modeled as a Pasternak shear layer, while the naturally occurring saturated soft soil has been idealized by a Kelvin–Voigt model and the stone columns by Winkler springs. The nonlinear behavior of the granular fill, the stone columns and the soft soil has been represented by hyperbolic constitutive relationships. The governing differential equations of the soil–foundation system have been derived and presented in a non-dimensional form. These equations have been solved using appropriate boundary conditions by means of an iterative Gauss–Siedel technique. A detailed parametric study has been conducted to investigate the influence of various parameters, such as the magnitude and the velocity of the applied load, viscous damping, the diameter and the spacing of the stone columns, the ultimate resistance of the soft soil and the stone columns, the relative stiffness of the stone columns and the average degree of consolidation on the response of the soil–foundation system. All these parameters have been found to significantly influence the response of the infinite beam. However, the ultimate shear resistance of the granular fill has been found to have a negligible effect on the response of the system.