Numerical investigation of the effect of geofoam on the dynamic behavior of embankments

Geofoam is gaining in popularity as a lightweight alternative to soil for construction of embankments. However, its properties are significantly different than soil, and the dynamic behavior of the embankment is affected by the presence of the geofoam. Herein, twodimensional numerical modeling of a simple embankment was performed to quantify the effect of geofoam on the dynamic behavior of the embankment. The dynamic responses of three embankments, one constructed entirely of soil, one constructed entirely of geofoam, and one constructed of geofoam with a soil veneer, were simulated. With respect to surface shaking, accelerations on the surface of the geofoam embankments were higher than those on the surface of the soil embankment. With respect to liquefaction, cyclic stress ratios of subgrade soils beneath the geofoam embankment were higher than those beneath the soil embankment, primarily due to the reduced effective stress caused by using geofoam instead of soil. These observations indicate that caution is warranted when using geofoam in areas of high seismicity to properly anticipate the effect of geofoam on the behavior of the embankment and subgrade during strong ground motion shaking.