A numerical study on the use of geofoam to increase the external stability of reinforced soil walls

摘要

ABSTRACT: The potential benefit of placing a panel of compressible (i.e. expanded polystyrene)ngeofoam behind the reinforced zone of mechanically stabilized earth (MSE) walls is investigatednusing a numerical modeling approach. A panel of geofoam is placed immediately behind thenreinforced zone during the construction phase of an idealized plane-strain reinforced soil segmentalnwall model. The analysis procedure includes the modeling of soil compaction. The magnitudes andndistributions of earth pressure behind the reinforced zone in the wall models with and without thengeofoam panel are compared to quantify the reductions in lateral earth pressure, resultant lateralnforce and overturning moment expected due to the placement of the geofoam material. Predictednmagnitudes of facing lateral deformation and reinforcement strains are also compared among casesnstudied in order to evaluate the effect of geofoam on wall serviceability. It is shown that placingngeofoam behind the reinforced zone can reduce the maximum lateral earth pressure behind thisnzone by as much as 50% depending on the geofoam thickness and stiffness values. The magnitudesnof total lateral earth force (i.e. the resultant force of the lateral earth pressure distribution) behindnthe reinforced mass and overturning moment about the wall toe are shown to decrease by 31% andn26%, respectively. These findings point to a significant potential for using geofoam to reduce thenlateral earth pressure demand on MSE walls (i.e. as opposed to rigid retaining walls examinednpreviously) and thereby increase their serviceability and their factors of safety against externalninstability.