ABSTRACT
The sliding of an inner slope, referred to as macro-instability, is one of the main failure modes for dikes. This failure mostly occurs when the outside water level elevates, resulting in an increase of pore water pressures in and beneath the dike and ultimately in a decrease of undrained shear strength. In this study, the inner slope stability or macro-stability at one of the dike cross-sections between Krimpen aan den IJssel and Gouderak in the province of Zuid-Holland in the Netherlands, is evaluated by using the constitutive model SHANSEP Mohr-Coulomb (MC) in PLAXIS. The safety factor against macro-instability is assessed based on the SHANSEP approach. To validate the model, the calculated safety factor and the predicted slip circle are compared with those obtained using the Uplift-Van model using Deltares software, D-Geo Stability. The discrepancy of the results between the SHANSEP MC model and the Uplift-Van model is discussed and the modelling aspects for macro-stability assessments for river dikes are outlined.
