Serviceability Analysis of Geomembrane in Geosynthetic-Reinforced Column-Support Platforms: Fid-Bau Portal

Serviceability Analysis of Geomembrane in Geosynthetic-Reinforced Column-Support Platforms

Huang, J. / Han, J. / Collin, J. G.

Geomembrane, a low permeable synthetic material of relatively low elastic modulus and tensile strength, has been widely used as a barrier/containment system. Guidelines in the USA typically limit the allowable strain in geomembrane during service up to 5%. This paper addresses a townhouse development project in the USA where a layer of geomembrane was placed within the foundation system because of environmental considerations. The foundation system consisted of a load transfer platform with four layers of geogrid reinforcement over Vibro-Concrete Columns (VCC) in a triangular pattern. Due to the complexity of this problem, a finite difference method was used to compute the tension and strains in the geomembrane during construction and service. A linearly elastic-perfectly plastic model with Mohr-Coulomb failure criterion was employed to model the foundation soils, the load transfer platform fill, and VCC columns with a very high cohesion. The townhouse strip footing was modeled as a linearly elastic material. Geogrid elements were used for both geogrid and geomembrane sheets. Distributed loads of two different magnitudes were applied at locations of footing and floor respectively to simulate the footing load and the floor surcharge. The construction was modeled in six stages. The analysis showed that the geomembrane would survive during and after the construction of the geosynthetic-reinforced column-supported platforms when subjected to footing and floor surcharge loading.