NUMERICAL ANALYSIS OF GEOCELL REINFORCED FOUNDATION SAND BEDS AND COMPARISON OF CELLULAR AND PLANAR GEOSYNTHETIC REINFORCING SYSTEMS

Geocell is a three-dimensional geosynthetic product which can be used to stabilize foundations by increasing bearing capacity and reducing settlements. Geocells have completely dierent mechanisms compared to the traditional forms of geosynthetics (planar geosynthetics). Their three dimensional geometry causes extreme lateral connement for the inlled soil, which leads to an increase in soil strength and stiness and a decrease in surface permanent-deformation.
Many laboratory and eld tests have demonstrated the eectiveness of geocell reinforcement systems in dierent elds. Due to several advantages, the geocell is in the process of practical development. However, a considerable gap exists between applications and theories for mechanisms of geocell-reinforced foundations. There are relatively extensive laboratory studies in the eld of geocell reinforcement, but, because of its complexity, numerical modeling of geocell reinforcement, which is essential for investigating its behavior, has rarely been undertaken.
This paper presents a numerical model of geocell reinforced foundation sand beds. In this numerical study, in order to simulate the three dimensional nature of the geocell accurately, the geocell and soil are simulated separately using the 3D Finite Dierence Method (FDM) of FLAC3D. The geocell is simulated using geogrid structural elements, and the elastic-perfectly plastic Mohr- Coulomb model is used for modeling the behavior of soil. In order to verify the modeling, at rst, a single geocell reinforced soil is modeled and compared with the equivalent laboratory test presented in the literature. Then, the model is extended to geocell foundation beds.
Finally, in this research, the placement conditions under which the geocell layers have the highest eciency (highest bearing capacity with the least cost) are determined in order to reduce the costs as much as possible. Also, a comparison is made between the performance of the 3D geosynthetic reinforcement and planar form with the same mass of used material (as two reinforcing systems with similar materials but dierent behavior mechanisms) to determine the system with higher eciency