Mitigation of Landslides in Colorado and Wyoming Using Geofoam Fill

Mitigation of landslides and failing embankment fills in low strength clay materials and over-steepened slopes has been an ongoing problem for both the Colorado Department of Transportation (CDOT) and the Wyoming Department of Transportation (WYDOT). Yeh and Associates, Inc. (Yeh) has been involved with mitigation of failing slopes using expanded polystyrene (EPS), otherwise known as rigid cellular polystyrene geofoam, on three separate corridors in Colorado and one corridor in Wyoming. The projects generally entailed providing a mitigation system to stabilize failing roadway embankments. The roadway pavement sections were generally in distress, with loss of one or more travel lanes after widening of the roadway from two lanes to three lanes. The paper describes the overall geotechnical conditions, design concepts, constructability issues, and long-term effectiveness of the mitigation systems.