عنوان مقاله [English]
Many structures are being constructed on expansive soil every year. A considerable part of these structures are damaged such as cracks and a part of them are destroyed. When the irrigation canals are located on problematic soils like expansive and dispersive soils, different damages may occur. Top layers of Tabriz plain are generally consisted of fine grain soils and clays. A comprehensive site investigation was undertaken and the results show that the swelling potential varies from low to medium-high. Some parts of the AjiChay main canal of Tabriz (East Azerbaijan) suffered cracks and small uplifts. After investigation it was shown that these damages could be caused by soil bed swelling. In this paper this hypothesis was investigated. Different tests were undertaken to understand the phenomena and a countermeasure method was undertaken to reduce damages.In order to evaluate the effectiveness of countermeasure method, a part of canal was selected and filled with water and the deformation of canal caused by swelling was studied.