Numerical and experimental modeling of geotextile soil reinforcement for optimizing settlement and stability of loaded slopes of irrigation canals

Geotextile is a geosynthetic-based soil stabilization technique recently used to reinforce the soil and stabilize the canal slopes. In this study, the effect of using different nonwoven geotextile configurations on soil reinforcement and slope stability for irrigation canals subjected to loads on a canal berm was experimentally and numerically investigated. First, a laboratory model was constructed, the materials were prepared, and testing procedures were performed. The experiments were conducted to investigate settlement due to footing loads of width B acting on a canal berm in a dry case under different scenarios of geotextile soil reinforcement. Different lengths (l = 1.5, 2.0, and 4.0 B) and depths (d = 0.5, 1.0, and 2.0 B) of geotextile layers were used. Second, the experimental data were used to calibrate and validate the PLAXIS-3D model. Third, a series of simulation scenarios were conducted to investigate the joint effect of geotextile configurations on settlement. After that, the PLAXIS-3D model was used to determine the factor of safety (FoS) of the Ismailia Canal (i.e., real case study) side slope under different loading conditions with and without geotextile reinforcement. Finally, a cost analysis was conducted for Ismailia Canal under different geotextile configurations. Results showed a close agreement between experimental and PLAXIS-3D simulation results. Results also showed that geotextile reinforcement enhances bearing capacity ratio (BCR) and reduces settlement. As the length of the geotextile layer increases, the BCR increases and the settlement decreases. Among the investigated geotextile configurations, the optimum configuration was found when l = 4 B and d = B. In addition, soil reinforcement by geotextile for Ismailia Canal under an excavator load of 40 tons lowered the settlement values by about 10%, whereas its effect on the slope stability FoS was almost inconsiderable. Therefore, geotextile reinforcement can be used to relatively reduce settlement near canals’ embankments.