Experimental and Numerical Evaluation of Reinforcement Mechanism of Geocells

Geocells is a commonly adopted reinforcement element for foundation and pavement applications. It is inferred from the existing literature that the geocell offers an all-round confinement to the infill material in addition to the lateral restraint and bearing support as a reinforcement mechanism. However, quantification of the confinement effect provided by the mattress is a challenge. To quantify and demonstrate the geocell reinforcement mechanism, an extensive experimental and numerical studies were undertaken. In the experimental study, a large test tank was adopted to build test sections with and without geocell reinforced granular bases over weak subgrades. Several earth pressure cells were installed along the interface of the geocell reinforced base and weak subgrade layers, and within the geocell pockets. A monotonic loading was applied to understand the reinforcement behavior of the geocell mattress. In this paper, the actual three dimensional honeycomb shape of the geocells is modeled using Fast Lagrangian Analysis of Continua in 3D (FLAC3D), a finite difference software and the geocell-soil mechanism is studied from the stresses and strains developed within the geocell mattress. The numerical models have predicted the experimental pressure-rut depth responses with about 95% accuracy. The confining stresses developed within the geocell mattress and at the interface were recorded to understand the mechanism of geocell reinforcement. It is observed that the confining stress in the geocell mattress is not uniform throughout the mattress, however, it decreases linearly from the point of loading