Bearing Capacity of Square Footing on Cohesive Soil Reinforced with Geocomposite

Abstract

AbstractVarious reinforcing techniques have been used till now for the bearing capacity improvement of Shallow Foundations over soft clay. Of all the techniques, Geosynthetic reinforcement has proved to be a cost-effective solution. Many researchers have focused on behaviour of Geotextile or Geogrid alone as a reinforcing material. But less research is available on Geocomposites. In this study, the combination of Geotextile and Geogrid (i.e. Combigrid) is used as a single reinforcing material in a single layer which is more economical than using different materials in different layers, hence the purpose of my research is to provide a cost-effective ground improvement technique in soft soil by using a single layer of geocomposite at optimum depth and length. Laboratory tests are performed on various configurations of the reinforcement layout to investigate the bearing capacity of reinforced clay. The model test tank of size 280 mm × 280 mm × 240 mm and square footing of width 5 cm is used. First the model tank is tested in a Universal Testing Machine with clay only and the Bearing capacity of unreinforced clay is recorded, then for 0.3B depth of reinforcement, three varied lengths of reinforcement (3B, 4B, 5B) are tested. Similarly, for 0.5B, 0.7B and 0.9B depth, the length of reinforcement varied from 3 to 5B (B = width of footing) and for each case, the bearing capacity is calculated. Results are compared in terms of BCR and it is found that Combigrid helps in bearing capacity improvement of soft clay upto four times more than the Unreinforced Bearing Capacity.KeywordsBearing capacityReinforcementCombigridUniversal Testing MachineGeogrid