Centrifugal model tests on deterioration process of canal under cyclic action of coupling wetting-drying and freeze-thaw

The complex action of coupling moisture and heat in seasonally frozen soil regions is the inducement of deterioration and instability of hydraulic structures such as canals. A set of centrifugal model test equipment for canal under the cyclic action of coupling wetting-drying and freeze-thaw in seasonally frozen soil regions is developed, which realizes the simulation of cyclic action of coupling moisture and heat during the process of wetting-drying and freeze-thaw in the centrifugal field. The centrifugal model tests are conducted to investigate the deterioration process of the canal in north Xinjiang under the cyclic action of coupling wetting-drying and freeze-thaw. The tests results show that the cyclic action of coupling wetting-drying and freeze-thaw makes the cracks of model canal expand, and eventually produces a deep transverse tension crack across the top surface of the canal, which leads to that the model canal has a tendency of instability from the tension cracks at the canal top. In this process, the infiltration depth of canal water increases and the infiltration volume decreases. The freezing rate and thawing rate show an upward trend. In addition, the final normal deformation at the canal slope is the largest, followed by that at the top of the canal and that at the bottom of the canal. The equipment and method adopted in the centrifugal model tests are applicable to the disaster researches on canals in cold regions.