Numerical Investigation on 1D and 2D Embankment Dams Failure Due to Overtopping Flow

摘要

This article provides three numerical investigations on the overtopping failure of embankment dams which are modelled with non-cohesive fill material. The first investigation is based on a one-dimensional approach in order to calculate the outflow hydrograph during dam overtopping failure. The written program calculates the flow parameters by solving the one-dimensional Saint-Venant equation. Furthermore, the bed evolution is calculated by solving the Exner equation with the finite difference scheme. Here, the model accuracy is increased by dividing bed slopes into three categories: zero slope (0.0-1%), mild slope (1%-20%) and steep slope (>20%). At each time step based on the real bed slope the bed load transport is modelled. In the second investigation the two dimensional open-source TELEMAC software has been modified in order to model embankment dam failure. This modification is done by calibrating slope correction formula in the sediment part of this software. Finally, the influence of different geometrical parameters on the outflow hydrograph of dam failure is numerically modelled. Our modelling results show that the downstream slope has significant influence on the outflow hydrograph in comparison to the other geometrical parameters.