The Use Of Geocomposite Drainage Layers To Mitigate Frost Heave In Soils

摘要

Frost heave in fine-grained soils below roadway pavements causes extensive and costly damage. In order to mitigate frost heave and associated damage, a geocomposite drainage net was installed in highway test sections along a 3.0 km reconstructed portion of US Route 1A in Frankfort and Winterport, Maine, to function as a capillary barrier to reduce frost heave and a drainage layer to accelerate thaw recovery. This section of road had previously been plagued by pavement cracking, rutting, and potholes requiring frequent and costly maintenance to maintain a trafficable pavement surface. Thermocouple strings were embedded in the test sections at six-inch (152-mm) vertical intervals and temperatures were recorded with depth within the section. Ambient air temperatures and roadway elevations were also documented. This paper deals only with the influence of the geocomposite on frost heave. The freezing index, frost penetration and heave for the winter of 1997-1998, immediately after construction are reported. The results suggest some benefit when the geocomposite is placed within the subgrade. It appears that the primary benefit of the geocomposite is that it provides dewatering benefit during spring thaw ―probably controlling the elevation of the water table. There may also be an effect of the cut/ fill depths that masked the effectiveness of the geocomposite drainage layers.