Nima Gorji - Department of Civil Engineering, Islamic Azad University - Pardis Branch
Mohammad. M. Toufigh - Department of Civil Engineering, Shahid Bahonar University of Kerman

In this study a new numerical solution is developed to estimate the ultimate bearing capacity of reinforced soil foundations (RSF) with geogrid reinforcement considering a various soil types. The method is based on the classical bearing capacity theories of shallow foundations such as Terzaghi or Meyerhof theories, however is applicable to reinforced shallow foundations. In this finite element method, a model of unreinforced soil foundation was analyzed; using classical bearing capacity theories, under the ultimate load and the amount of footing settlement was calculated. Then, models of reinforced foundations were allowed to settle to this certain amount and the bearing capacity of reinforced soil foundations was back calculated. A ratio BCR was defined as the bearing capacity of a reinforced soil foundation to an unreinforced soil foundation. The number of reinforcement layers (N), the top layer spacing (u), and the vertical spacing of reinforcement (h) were investigated as three important parameters on BCR. It was concluded that applying reinforcement can considerably increase the bearing capacity of soil foundations up to a BCR of 2.598, for a settlement ratio of 9%. The results of the developed finite element method were compared to preexisting experimental data from laboratory model tests on reinforced soil. Good agreement between the prediction of this method and experimental data confirms the reliability of the new developed method.

Back calculation, Bearing capacity, reinforced foundation, Finite element method