Road damage due to ground freezing in the Republic of Korea and a method to predict frost depth for pavement design

Some of the roads in the Republic of Korea suffer serious damages caused by the frost heaving during the winter and the thaw weakening preceded by noticeable or unnoticeable heaving during the spring melting period. In order to eliminate such damage the depth of frost penetration below the pavement should be considered for design purposes. The frost depth for pavement design can be theoretically determined based on the modified Berggren equation. To facilitate use of the equation, two varieties of maps were produced showing the distribution of design freezing index values and the zonal distribution of freezing periods. A diagram also was constructed illustrating the relationship between freezing index and thermal ratio. Using the above information, it is possible to estimate the depth to which frost penetrates anywhere in the Republic of Korea.