GPR monitoring of cryogenic processes in subgrade soils

Road operation in areas with frozen soils requires monitoring of subgrade soils due to seasonal changes of their properties as well as development of negative cryogenic processes. Monitoring subgrade soil properties and condition is most effective using GPR. The results of theoretical and experimental studies of subgrade soils of roads in the North revealed the main wave characteristics of GPR data received by sounding road pavement deformations. Based on the characteristics revealed a method to identify negative cryogenic processes and monitor soil condition has been proposed from data of seasonal changes. A distinctive feature of the proposed method is the quantitative determination of soil moisture on the basis of comparative data obtained during maximum freezing and maximum defrosting of the soil. The feasibility of the proposed method is demonstrated by GPR survey of roads in Yakutia.