Abstract
This paper presents a method to analyze strip footing resting on granular layer over weak soil improved by end bearing or floating granular piles. The granular layer beneath the strip footing idealized as incompressible shear layer. The weak soil idealized as soft Winkler springs and the granular piles idealized as stiff Winkler springs. These springs connected at their ends by a thin membrane under uniform tension to overcome the drawbacks of Winkler model related to the shear effect or the continuity of the granular piles-weak soil composite. Hyperbolic relationships used to represent the nonlinear behavior of weak soil and granular piles. Granular piles of different diameters, lengths, stiffness and arrangements can be modeled. The numerical solution obtained by the finite element method. The validity of the present analysis verified through comparisons with the field measurements, other existing analysis method and PLAXIS finite element program. A parametric study for a strip footing subjected to seven concentrated column loads carried out to study the effect of various parameters on the behavior of the soil-strip footing system. These parameters include number of granular piles, modular ratio, stiffness of granular layer, diameter of granular piles, length of granular piles and arrangements of granular piles. It is found that stiffness of granular layer has little effect compared to a significant effect of other parameters on the vertical and differential displacements and the induced bending moment of the strip footing.