Thermal modeling of Anchorage driveway culvert with addition of insulation to prevent frost heaving

Abstract

A predominate problem in cold regions, and specifically in Anchorage, Alaska, is frost heaving pavement above culverts in residential driveways. The culvert increases heat loss in the subgrade materials during winter months and allows the soils below the culvert to freeze, which is not an issue if the underlying soils are non-frost susceptible material. However, there are numerous locations in Anchorage and other parts of Alaska where the underlying soils are frost susceptible which result in frost heaving culverts under driveways that cause damaged pavement and culvert inverts that are too high. The seasonal heave and settlement of culverts under driveways accelerates pavement deterioration. A model of this scenario was developed and several insulation configurations were considered to determine a suitable alternative for preventing pavement damage from heaving culverts. The model used material properties for typical Anchorage area silty sand. The model showed that insulation could be used below culverts to prevent differential frost heave at the culvert. In addition, this technique uses typical construction materials and is reasonable for a typical residential dwelling contractor to complete during the construction of the home.