The sensitivity evaluation of the factor of safety against planar failure of riverbanks via the variation of effective parameters in bank stability analysis

The study of mass failure of river banks is important because of its role in producing areasonable amount of sediments as well as the development of the floodplain. In order toinvestigate the processes of banks failure, it is necessary to determine effectiveparameters which influence riverbank stability. Due to technical and practical issues,however, the determination of some of the parameters is not simple. Hence, based onavailable data and current knowledge and experiences, estimations were made for theseparameters. There is a lack of practical research literature on how to determine the effectsof these parameters on bank stability. Therefore, in this research, a model of riverbankstability analysis was simulated using the data from three sites in United States ofAmerica and one site in Italy. The stability of riverbanks and the impacts of variousparameters, based on the sensitivity analysis of the factor of safety against planar failure,were investigated. From the results of the analysis of the available data, it is concludedthat in descending order, the variation of ground water level, bank angle, river flow level,and specific weight of bank materials are the most important parameters affecting bothbank stability and the value of safety factor against bank failure. Also, the results showthat the tension crack depth, cohesion, internal friction angle, and the rate of increase inshear strength due to an increase in matric suction, have a little influence on thesensitivity of safety factor of riverbanks.