Application of geosynthetics reinforcement in freezing thawing roads: A case study from Norway

Low bearing capacity during the thawing period gives a lot of problem related to rutting and edge deformation on roads in Nordic countries. Geosynthetics reinforcement has been used in some road rehabilitation projects to improve the bearing capacity and to reduce the need for load restrictions on the traffic during the thawing period. This paper will present a case from the island Hitra in Sor-Trondelag, Norway, where different types of geosynthetics reinforcement has been used in road rehabilitation project. The sub soil in this area consists to a large extent of soft peat. During the thawing period the bearing capacity of the road was very low and large deformation required restrictions on the traffic load. SINTEF Rock and Soil Mechanics group have evaluated the results from the reinforced section on this road. This paper will present different types of field measurements and long-term observations of the deformation to evaluate the effect of the geosynthetics reinforcement. The results indicate that the rehabilitation project has been successful as the rutting and deformation are within acceptable range on all sections. The plate load tests indicate that the resistance against plastic deformation is significantly high, and so the amount of rutting will be low as well.