TN2. Failures during river dike construction

1. In Belgium, the river Scheldt and its affluents (Fig.l) are subjected to a semi-diurnal tidal regime over a total length of 300 km. At several occasions in the past extreme high tides due to north west storms on the North Sea caused inundations by overflow or dike failures. Since 1977 the Belgian Ministry of Public Works started heightening and reinforcing

the existing river dikes. As in many locations these works have to be executed on soft alluvial layers, and although special precautions are taken, local failures sometimes occur during construction. In these cases and also at places where the existing dikes, river banks or other defence structures had already undergone some damage, special repairing or stabilizing techniques had to be applied.