Evaluation Behavior of Circular Footing Located on Sand Bed Reinforced with Geocell

Abstract

The rigid base proximity (such as stiff rock) under a relatively thin sand stratum and employing a 3D reinforcement (e.g. geocell) can tend to significant improvement in the bearing pressure of shallow footings. In this study, the behavior of circular footings located on unreinforced and geocell-reinforced thin sand layer was investigated. The simultaneous or individual effect of footing dimensions, sand layer thickness, and geocell reinforcement on the bearing pressure and settlement was studied by conducting large-scale model tests. The influence of soil layer thickness on footing behavior was elucidated by considering optimum dimensions and location for geocell reinforcement. Based on the results, improvement in the bearing capacity and settlement reduction for both unreinforced and reinforced footing bed was seen when the sand layer thickness is lower than two times of the footing width. Additionally, the effectiveness depth of the rigid base for both cases was obtained two times of footing width. The combination of geocell reinforcement and rigid base as lateral and vertical confinement factors, led to increase in the bearing capacity and settlement reduction at the failure point up to 45% and 53%, respectively. The tests results were served to define new factors extending classical bearing capacity equations for footings located on thin soil at reinforced and unreinforced cases. The comparision of this study’s achievement with the previous investigations confirmed their good agreement.