A novel force-based approach for designing armor blocks of high-crested breakwaters

Rubble-mound breakwaters are common marine structures that provide a safe area for human coastal activities. The stability of these structures against sea-waves requires their seaward slope to be protected by an armor layer consisting of natural rock or concrete units. To provide a safe breakwater, it is reasonable to establish a relation between the exerted wave loads and the stability of the armor units. However, up to now, the empirical design equations, derived from model tests, relate wave parameters to armor weight, and keeps the effect of wave loads in a black box. In this paper, a new approach, based on numerically-derived wave loads on the armor, is presented to evaluate the stability of these protective units. Results indicate that by increasing wave height, the weight of the armor units does not necessarily increase. Wave breaking type strongly inuences the applied loads and stability of the armor units. New dimensionless numbers are introduced to provide relationships between wave parameters and stability indices of breakwater armor units at different locations. This approach clarifies the ambiguities of the design process caused by the complex ow field, especially the wave breaking type near the breakwater.