Experimental Investigation on the Swelling Behavior of Expansive Soils with EPS Geofoam Inclusion

Abstract

Swelling pressure of expansive soils can impose significant threat to the infrastructure built on them. Placing of compressible inclusion material, such as expanded polystyrene (EPS) geofoam, in expansive soils can effectively reduce the swelling pressure acting on the structure. This paper describes the experimental design, results of the tests used to investigate the use of compressible EPS in the form of geofoam layer (GL), geofoam column (GC) inclusion to reduce the swell potential, and swelling pressure of expansive soils. The tests were carried out on large one-dimensional consolidation equipment which can accommodate the California bearing ratio mold. Two different EPS geofoam densities were tested on two types of soil with varying swell potential under swell–compression test. The results of the tests are compared for the soil samples with and without GL and GC inclusion. The test results demonstrate that the percentage reduction in swell and swelling pressure is increased with increasing the thickness and cross-sectional area of GL and GC inclusion in expansive soils. In addition, the optimal EPS density was determined with respect to the maximum reduction in swelling.