doi:10.3850/GI149

ABSTRACT

The paper reports the findings of an investigation regarding the influence of the design parameters (e.g., Relative flexural rigidity of beams, Relative stiffness of granular media, Relative length of beams, and Relative depth of reinforcement) on the settlement response of a strip footing subjected to a central vertical load and resting on a reinforced elastic foundation bed. Both the footing and the reinforcement are idealized as beams, and the granular beds are represented by linear Winkler springs considering the modulus of subgrade reaction along the beam-soil interface to be variable depending on the confining pressure acting at any point on the contact surface. Non-dimensional equations governing the settlement response of the foundation are derived and subsequently solved iteratively by using Finite Difference Technique. It is observed that the variation in the magnitude of the parameters significantly affects the settlement response; in some cases, the difference in the response is as high as 130% due to the change in the parametric values. The study also reports the optimum values of the parameters for achieving the maximum benefit in terms of settlement reduction. The reported study helps in assessing the extent of improvement in the settlement characteristics of the footing (as a result of the provision of a reinforcement at the interface of the upper and lower granular medium). Comparison of the settlement responses of the footing resting on unreinforced and reinforced elastic foundation beds reveals a significant improvement of the order of 85% in the settlement profile of the footing. Thus, application of reinforcement over a weak granular soil stratum overlain by a compacted granular bed can be used as an effective ground improvement technique.

Keywords: Reinforced elastic foundation; settlement response; variable subgrade modulus; parametric study; ground improvement.

© 2010 by Geotechnical Society of Singapore (GeoSS)