Breach modelling by overflow with TELEMAC 2D: comparison with largescale experiments

¹ Cerema, Direction territorial Méditerranée, 30 avenue Albert Einstein Aix en Provence, CS 70499, 13593 CEDEX 03, France
² DREAL Nord Picardie, 56 rue Jules Barni, 80040 Amiens Cedex, France
³ United States Department of Agriculture - Agricultural Research Service – 1301 N Western Rd Stillwater Oklahoma, USA

^a Corresponding author: Christophe.laroche@cerema.fr, christophe.laroche.job@gmail.com

Abstract

An erosion law has been implemented in TELEMAC 2D to represent the surface erosion process to represent the breach formation of a levee. We focus on homogeneous and earth fill levee to simplify this first implementation. The first part of this study reveals the ability of this method to represent simultaneously both formations of the breach and the scour hole at the rear of the levee. The resistance or no of the levee seems consistent with the resistance of the soil material given by a standard classification. But this first part has showed that the lateral development of the breach cannot be represented. In the second part of this study, a simply widening of the breach method based on continuous surface erosion process, has been implemented. The comparison with large scale experiments which has been made, shows that both dynamics of the breach formation and the width are not correctly estimated with the only one surface erosion process. Further developments have to be done to integrate the headcut erosion process and mass failure as sliding of the sides of the breach or undercutting.