Effects of Geofoam Particles on Geotechnical Properties of Clay-dune Sand

Nowadays, new materials are widely used for improving the bearing capacity of the soils and geosynthetics include the type of these materials which are utilized in this regard. In addition, the geofoam panel type of geosyntethic materials is useful and an alternative for backfill in retaining wall or pavement layers. The present research mainly aimed to investigate sthe effects of geofoam particles (0.2, 0.5, & 1%) on improving the bearing capacity of the clay-sand mixture. To this end, dune sandy soil (passed from sieve No.30 and residue on sieve No.50) was provided from Shore of the Lake Urmia and mixed with kaoline industrial clay at 15, 30, and 50 percentages. Then, compaction, uniaxial in three loading speed (0.5, 1, & 1.5 mm/min), direct shear (in vertical stresses 1, 2, & 3 kg/cm2), and falling head permeability tests were performed to evaluate the influence of geofoam particles on geotechnical properties of the mixed soil. The results showed that maximum dry density and elastic modulus increased by a 0.5% increase in the geofoam in the soil mixture. Meanwhile, the shear strength of the specimens increased as well. Finally, permeability and the drainage condition improved by adding geofoam to the specimens.