Abstract: Research on the mechanism of frost damage of canal with concrete lining under the influence of solar radiation in seasonally frozen regions has some limitations. In view of this, we established finite element model with unsteady temperature field and phase change based on prototype observation data to analyse the relationship between thermal regime and solar radiation absorption in frozen period. Actual environmental factors, such as solar radiation, air temperature and wind speed, were considered in the model. The slope of Jinhui main canal’s E-W directional segment with concrete lining was taken as a case study. The simulation result indicates that the lateral asymmetric and uneven thermal field of canal foundation is the main cause of canal lining’s frozen damage in cold regions; the average daily solar time and solar radiation of southern and northern slopes are also lateral asymmetric and uneven; the average temperature difference of shallow canal foundation (0.4 m) is in polynomial relation with the average solar radiation difference; the maximum temperature difference of canal foundation is in linear relationship with the depth; the solar radiation absorption coefficients have great influence on the heat exchange of canal foundation; the maximum temperature difference between sunny slope’s and shady slope’s lining board surface increases linearly with the enlargement of solar radiation absorption coefficient; the southern slope’s frozen depth decreases by 25% and the northern slope’s by 37% when the solar radiation absorption coefficient increases from 0.65 to 0.8.

Key words: solar radiation, canal with concrete lininging, meteorological parameters, southern and northern slopes, lateral asymmetry, mechanism of frost damage