Preliminary design procedure for EPS-block geofoam lightweight fill in levees overlying soft ground

Construction of levees on soft foundation soils, such as peats or soft clays, has long been problematic. Two main approaches for coping with the problem are (1) to improve the engineering properties, e.g., shear strength and compressibility, of the foundation soils or (2) to reduce the weight of the levee and thus the load applied to the soft foundation soils. The use of expanded-polystyrene (EPS)-block geofoam for the function of lightweight fill is one alternative to reducing the weight of the levee. Despite several case histories reported in the literature of EPS-block geofoam levees, EPS-block geofoam levees overlying soft ground are not currently extensively used internationally and in U.S. practice because comprehensive design guidelines have been unavailable. Therefore, there is a need in the U.S. to develop a detailed design guideline for the use of EPS-block geofoam in levees in routine practice. In an effort to address this need, this paper presents a proposed framework for developing a comprehensive design guideline for the use of expanded-polystyrene (EPS)-block geofoam for levee construction over soft ground. The basis of the proposed framework is the guideline for geofoam applications in highway embankments that was published in the National Cooperative Highway Research Program (NCHRP) Report 529 and the current ongoing NCHRP design guideline work for the use of EPS-block geofoam in slope stabilization and repair