Model studies on circular footing supported on geocell reinforced sand underlain by soft clay

Abstract

The effectiveness of geocell reinforcement placed in the granular fill overlying soft clay beds has been studied by small-scale model tests in the laboratory. The test beds were subjected to monotonic loading by a rigid circular footing. Footing load, footing settlement and deformations on the fill surface were measured during the tests. The influence of width and height of geocell mattress as well as that of a planar geogrid layer at the base of the geocell mattress on the overall performance of the system has been systematically studied through a series of tests. The test results indicate that with the provision of geocell reinforcement in the overlying sand layer, a substantial performance improvement can be obtained in terms of increase in the load carrying capacity and reduction in surface heaving of the foundation bed. An additional layer of geogrid placed at the base of the geocell mattress further enhances the load carrying capacity and stiffness of the foundation bed. Its beneficial effect decreases with the increase in the height of the geocell mattress. A seven-fold increase in the bearing capacity of the circular footing can be obtained by providing geocell reinforcement along with a basal geogrid layer in the sand bed underlying soft clay.