Numerical model to predict the settlement response of two nearby foundations due to geotextile slippage

Abstract

In this paper, a numerical study is undertaken on the settlement response of two nearby flexible loads resting on a reinforced granular bed underlain by a soft soil, considering plain strain loading conditions. The finite element code PLAXIS-8 has been used. The granular fill, soft soil and geosynthetic reinforcements are considered as linear elastic materials. The geosynthetic reinforcement is modeled with interface elements for allowing slip between the soil and reinforcement. When no interface elements were used, the geosynthetic reinforcement was modeled as if there were no slip. It appears that allowing slip has a negligible effect on the settlement predicted. The results obtained from the present investigation showed that as the number of reinforcement layers increase up to three layers, the vertical stresses in the loaded region decreases causing maximum settlement reduction at a decreasing rate of 16% and 20% for 3-layers without and with slippage respectively. A parametric study has been carried out to bring out the effect of slippage of the reinforcement layer on the settlement response in dry and saturated soils. The increase in the settlement is not significant when the slippage of the reinforcement is considered. An interesting observation in this note is that the settlement was about 10% less when there were two nearby footings compared to when there was only one. The interaction between the footings resulted in reduction in the settlements, possibly due to reduced confining pressures.