Axi-symmetric Analysis of Geosynthetic-reinforced Granular Fill-soft Soil System with Group of Stone Columns

Abstract

The paper presents a mechanical model to predict the behavior of geosynthetic-reinforced granular fill resting over soft soil improved with group of stone columns subjected to circular or axi-symmetric loading. The saturated soft soil has been idealized by spring-dashpot system. Pasternak shear layer and rough elastic membrane represent the granular fill and geosynthetic reinforcement layer, respectively. The stone columns are idealized by stiffer springs. The nonlinear behavior of granular fill and soft soil is considered. Consolidation of the soft soil due to inclusion of stone columns has also been included in the model. The results obtained by using the present model when compared with the reported results obtained from laboratory model tests shows very good agreement. The effectiveness of geosynthetic reinforcement to reduce the maximum and differential settlement and transfer the stress from soft soil to stone columns is highlighted. It is observed that the reduction of settlement and stress transfer process are greatly influenced by stiffness and spacing of the stone columns. It has been further observed that for both geosynthetic-reinforced and unreinforced cases, the maximum settlement does not change if the ratio between spacing and diameter of stone columns is greater than 4.

Distribution of Stress on Stone Column-Reinforced Soft Soil under Cylindrical Storage Tank

“…Indraratna et al [11] adopted method of stone column conversion in concentric stone rings to analyze the vertical drain-improved soft soil under circular embankment. Studies carried out with mechanical model as well to predict settlement of axi-symmetrically loaded geosynthetic-reinforced granular fill resting on stone column-reinforced ground [12]. Dey et al [13] studied the flexural response of aqueduct resting on reinforced elastic foundation beds.…”