Modelling geosynthetic-reinforced granular fills over soft soil

In this paper, a new one-dimensional mathematical model is proposed for modelling geosynthetic-reinforced granular fills over soft soils subject to a vertical surcharge load. The geosynthetic reinforcement consists of a membrane (geogrid, or geotextile) placed horizontally in engineered granular fill, which is constructed over soft soil. The proposed model is mainly based on the assumption of a Pasternak shear layer. A new approach that consists of incorporating a deformation compatibility condition into the model is introduced. The compatibility condition eliminates the need for two uncertain model parameters that are required to calculate the shear stresses between the top and bottom granular fill layers and the geosynthetic layer. This compatibility condition also makes it possible to include the geosynthetic stiffness in the model. The results from the proposed model are compared to results from a two-dimensional finite element model and three other one-dimensional models reported in the literature. The comparison reveals that the proposed model gives similar results with respect to the settlement of a geosynthetic-reinforced granular base on soft soft and the mobilised tension in the geosynthetic layer.