Modelling of Geosynthetic-Reinforced Engineered Granular Fill on Soft Soil

Abstract

A ground improvement technique to improve the load-settlement behaviour of a soft foundation soil involves placing a geosynthetic-reinforced engineered granular fill over the foundation. In this paper, a mechanical foundation model for the analysis of such a reinforced soil system is proposed by representing the geosynthetic reinforcement, the granular fill, and the soft foundation soil by a stretched rough elastic membrane, a Pasternak shear layer, and Winkler springs, respectively. This model incorporates the effect of compaction of the granular fill by considering an appropriate shear stress transfer mechanism at the fill-geosynthetic interface. The results obtained using a wide range of parameter values have been compared with those computed using two other existing mechanical models of geosynthetic-reinforced granular fill-soft soil systems. It was observed from this study that the compaction of granular fill by a load higher than the working load results in a reduction of both the settlement of the reinforced foundation soil and the mobilized tension in the reinforcement. Additionally, the effect of compaction is reduced when the geosynthetic reinforcement is pretensioned.