Construction of Geofoam Block Embankments atop Existing Infrastructure in Transportation Projects

Abstract

Expanded polystyrene (EPS) block (geofoam block) is a mature geotechnology for constructing highway embankments. In addition to preventing bearing capacity and settlement related stability problems for the embankments constructed on soft soil sites, geofoam blocks are also used to construct embankments atop existing infrastructure. Selecting geofoam technology for these applications not only prevents the possible structural problems due to the lightweight nature of geofoam blocks but also eliminates costly remediation alternatives. The details of three well-documented and monitored different geofoam embankments constructed atop different existing infrastructures (buried pipeline, buried culvert and pile cap of drilled shafts for a deep excavation) are presented. The backgrounds of these projects, design considerations, construction and instrumentation details are discussed. The monitoring results were presented, and long-term performance predictions were evaluated. Numerical modelling effort was utilized to model the both short- and long-term behavior of geofoam embankments. Time-dependent behavior of the embankments under service loads were compared with numerical simulations. Constitutive modelling and related mechanical properties of geofoam blocks, which mimicked the long-term field behavior, as a function of geofoam density were proposed for future numerical modeling efforts.