Rubble Mound Breakwater Failure Modes: Failure Mechanisms Observed during ModelTests

摘要

Correlations between failure modes of rubble mound breakwaters has beeninvestigated by reviews of existing literature. The main part of the report is given by a description of observed failure mechanisms during model tests performed by DELFT HYDRAULICS. The main conclusions are: the presence of plunging waves caused by a very steep foreshore and landing on the toe structure led to huge toe structures that have to protect the armour layers; the geometry of the transition from the crest structure to the rear slope influences the stability of the crest structure; the geometry of the crest structure itself is important for the rear slope stability. Design criteria for rear slopes of berm breakwaters are given. Further, the destruction of a breakwater without a crest element, failure of a 90t blocks rear slope, and a composite breakwater is treated.