Effects of base geogrid on geocell-reinforced foundation beds

Abstract

The effect of a base geogrid layer below the geocell mattress in sand, sand overlying soft clay, and soft clay foundation beds has been studied using a series of laboratory scale load tests. A rigid circular model footing was used to apply static monotonic loading on the foundation beds with and without geocell reinforcement. The model test results show that the provision of an additional layer of planar geogrid at the base of the geocell mattress further increases the performance of the footing in terms of bearing capacity and reduction in surface heave of the foundation bed. It is also observed that the beneficial effect of the base geogrid layer becomes negligible with increasing height of the geocell mattress beyond the influence of the depth of the footing. Strain measurements in the base geogrid layer indicate that it is more effective with the limited heights of the geocell mattress. The earth pressure cells embedded in the subgrade soil provide evidence that when the base geogrid is provided below the geocell mattress, the footing pressure is distributed more uniformly over an extended area.