Effect of sand cushion reinforced with geogrid on heave of footing rested on expansive soil

Abstract

The swelling phenomenon of expansive soil is considered one of the most serious problems that face geotechnical engineers. The principal purpose of this study is to investigate the effectiveness of geogrid for reinforcing sand cushion on the heave of isolated footing resting on a top of a sand cushion underlined by highly active expansive clay using the large-scale box model. An artificial case study was imposed to prove the cost-effectiveness of using geogrid reinforcement with sand cushion. After performing experiments, there are many important conclusions that have been extracted from this study, for instance, using biaxial geogrid leads to control the heave of swelling soil due to the tension developed in geogrid. As well, the heave of the footing decreases slightly when the thickness of the sand cushion layer is changed from 0.75B to B.