Differential Frost Heave at Pipeline-Road Crossings

Abstract

Essentially all areas of Canada are affected by significant seasonal frost penetration. The effect of the frost penetration on roads and highways, especially the amount of total frost heave and the effect of the subsequent thaw, varies with soil type. Road design and construction must consider the effects of frost heave and subsequent spring thaw. The location and amounts of differential frost heave are especially important to pavement performance. Frost heave behavior can be manifest at pipeline crossings as “reverse frost heave”, where the ground above the pipeline does not heave as much as the adjacent ground. If the amount of differential heave within pipeline crossing is large, it can lead to rough, and potentially unsafe, driving conditions. In the case of pipeline crossings, if rough road surface conditions occur in the right of way, highway agencies typically request compensation for additional maintenance costs from the pipeline company. A case study that shows the effects of differential frost heave at a pipeline road crossing is presented.