Effect of aspect ratio of footings on settlement response of geosynthetic-reinforced granular fill-soft soil system

Abstract

In this paper, a simple mathematical model is used to study the effect of aspect ratio of footings on settlement response of unreinforced or geosynthetic-reinforced granular fill-soft soil system. The length-to-width ratio (aspect ratio) of footings is varied from 1.0 (square) to 3.0 (rectangular). The foundation model is formulated for single layer of reinforcement. Parametric studies are carried out for a range of shear modulus values of granular fill and ultimate bearing capacity values of soft soil. It is observed that the aspect ratio has significant effect on settlement response and mobilised tension in geosynthetic layer. Both settlement and mobilised tension below the loaded area increase with an increase in the aspect ratio of footing for a particular loading intensity with constant width of the footing and constant soil parameters. The effectiveness of the reinforcement in terms of settlement reduction decreases due to increase of aspect ratio. The settlement decreases with an increase in ultimate bearing capacity of soft soil or shear modulus of granular fill. However, the rate of reduction of settlement with an increase in ultimate bearing capacity or shear modulus decreases as the aspect ratio increases.