Numerical analysis of strip footing resting on geosynthetic-reinforced sand bed over soft soil

In this paper, the potential benefit of a reinforced sand overlying soft soil is studied. Such reinforced sand beds are often placed on soft soil strata for an efficient and economical transfer of superstructure load. A series of finite difference analyses are performed using two-dimensional plane strain model to investigate the behavior of geosynthetic-reinforced sand. The sandy soil, soft soil and geosynthetic reinforcements are represented by elastic materials. It is assumed that the deformations at the interface of the reinforcements and soil are the same. In numerical analysis, particular emphasis is paid for the effects of number of reinforcement layers, reinforcement stiffness and load intensity of footing on the ground surface settlements and mobilized tension in reinforcements. The results obtained from the present investigation have been compared with the results of finite element and finite difference analysis and also lumped parameter modeling. A reasonable close agreement is shown between the results. The results of current study indicate that reinforcing significantly improves the footing performance and also the efficiency of reinforced soil increase with increasing number of geosynthetic layers. Meaningful reduction in the ground surface settlement is observed when the number of reinforcement layer increases. The mobilized tension in the reinforcement layers increases when the stiffness of the geosynthetic layers increases. The differential settlement is also reduced due to application of multi geosynthetic layers as compared to the single layer reinforcement system.