Experimental Investigation of a Reduced-Scale Square Footing Model on the Geocomposite Reinforced Layered Soil

The geosynthetic is a polymeric material which is a cost-effective technique in reinforcing a weak terrain. The corrosive resistance of this material has found the possible use of it in the most exposed conditions. Therefore, the geosynthetics are the applicable solution to mitigate the anticipated excessive settlement in case of weak terrain. The present study investigated the behavior of a geocomposite material in a layered soil system. For this purpose, static plate load tests were carried out in a model steel tank of dimensions 100 cm x 100 cm x 100 cm. The soil was compacted into two layers of varying density starting with a soft layer with 0.85MDD at the bottom and followed with a stiff layer with 0.95MDD at the top. The load was applied by a 15 ton hydraulic jack and monitored through a proving ring of capacity 100 kN and the load carrying capacity and settlement behavior of a model square footing of size 200 mm x 200 was observed. Three types of geocomposite were manufactured by changing the tensile stiffness of the components viz. GCBX-40, GCBX-60, and GCBX-80. The basic configuration of every geocomposite was same and was made by using a geotextile layer in between the two geogrid layers which have significantly improved the surface frictional resistance due to the increase in the surface cover ratio and also the improvement in the interlocking effect on the soil grains due to the geogrid layers on both sides. The various layouts of geocomposite were introduced in this study besides the general planar layout and it was found that the confinement effect was increased within the soil layers. Therefore, the lateral moment of the soil grains was restricted due to the increased confinement which not only improved the bearing capacity factor but also the settlement reduction factor. The results revealed that the load carrying capacity was improved from 33.8 to 40.59% by using different types of geocomposite.