Abstract:

This paper presents results of laboratory model tests carried out on strip footings supported on geosynthetic reinforced sand beds. The relative performances of different forms of geosynthetic reinforcement (i.e. new lock enhanced integral geocell and geogrid mesh elements) foundation beds are compared using the same quantity of reinforcement in each test. Pressure-settlement curves, surface settlement and heave, deformation of two form geocells and glide planes are analyzed to understand the mechanism of different soil foundations. It is found that both form of geocells can decrease settlement and increase bearing capacity of the foundation. Vertical confinement of geocells is due to friction between the infill material and the geocell wall, which restrains soil from moving outside. The geocell-reinforced base can thus provide lateral and vertical confinement, tensioned membrane effect, and wider stress distribution, resulting in a better performance. The experiment also shows that geogrid mesh elements are more advantageous than new lock enhanced integral geocells. It is provided that there is no rupture of the material during loading. However, some ruptures can be found in joints of new lock enhanced integral geocells, which in turn principally decreased bearing capacity of the foundation. Meanwhile, significant observations on the difference in reinforcement mechanism for different forms of geocells are also presented.

Key words: geogrid, high strength geocell, reinforced foundation, bearing capacity, settlement