A Mechanical Model for Trapezoidal Canals Lined with Geomembranes and Anti-Slip Material During Freezing-Thawing Processes

Canals play an extremely important role in irrigation and conveyance of water. In cold regions, composite geomembranes are usually utilized as cushions in canals to mitigate frost heaving and seepage damages. In this study, a mechanical model for trapezoidal canals lined with double-layer geomembranes was developed to clarify the mechanisms of action of double-layer geomembranes for trapezoidal canals during freezing-thawing processes. The external and internal forces of a traditional concrete canal and two composite canals (i.e. a double-layer geomembranes canal and an anti-slip canal) were calculated using the mechanical model, and the tangential and internal forces on the slabs of three canals were compared, and analyzed. Furthermore, The reasons for the cracks in canal slabs and the sliding of slope slabs were explained using the freeze-thaw mechanical model. The results show that the tangential and internal forces in the double-layer geomembranes canal are minimal during the freezing period, while the tangential and internal forces in the traditional concrete canal are maximum. Conversely, during the thawing period, the anti-slip force of the anti-slip canal is larger than those of the double-layer geomembranes canal and traditional concrete canal subsequently. The mechanical model developed in this study will benefit the design of canals in cold regions.