Numerical Study of Canal Lining Behavior in Expansive Soils

Abstract

Cracking of unreinforced concrete lining in irrigation and drainage trapezoidal canals is one of the main problems that geotechnical engineers confront in different projects. This phenomenon occurs when the canals are constructed on unsaturated expansive soils and the moisture of bed soil changes in several conditions such as impounding and discharge of canal in different sessions, climate changes and transpiration. In the current paper, this phenomenon has been studied numerically and a real canal cross-section is modeled in the software. In order to predict the interaction behaviour between unsaturated expansive soil and concrete lining of canals at different moisture conditions, the special unsaturated soil behaviour model was selected. The required input mechanical parameters used in the soil behaviour model have been obtained from various laboratory experiments. The results of analysis show the location of maximum deformation and the amount of internal stress concentration on the canal lining. Using these results, the locations of joints on the surface of concrete lining can be optimized to reduce the effects of destructive interaction forces.