Comparison of EPS Geofoam and Stone columns in heave reduction of expansive soils

Abstract

To reduce the swell pressures in expansive soils usually granular piles are used, but due to lack of availability there is need of a material which is highly compressible and economical also. EPS Geofoams are obtained by expanding the polystyrene polymer which is a by-product obtained from the petroleum industry. As the drainability of the Geofoam is very less a layer of Geocomposite is surrounded over the geofoam especially for allowing the drainage. So, the mechanism involved in the study is that whenever a saturated soil swells in vertical direction this Geofoam will give room to accommodate the lateral swell which leads to reduction in the vertical heave and Geocomposite will dissipate the excess pore pressure generated during swelling of the soil. In the present study an attempt was made to predict the performance of EPS Geofoam and Geocomposite in reducing the soil heave due to constant infiltration. A two dimensional (2D) numerical model was developed using GEOSTUDIO 2012 to predict the behaviour of the swelling soil due to the inclusion of Geofoams as well as stone columns. Generally coupled and uncoupled analysis are performed to study the behaviour of the swelling soil but as the uncoupled analysis is more advantageous than coupled analysis it is performed in the present study.