Broad Toe Berm Jetty Head Design, Yaquina North Jetty

The proposed prototype repair section can be thought of as an integration of two drastically different rubblemound design concepts. The crest area of the repair is composed of parallelepiped stone placed in a highly controlled laid-up manner. The anticipated high stability of the crest is achieved from the tight interlocking of all armor units: If one armor unit is displaced from the crest, the neighboring armor units may unravel and the stability of the entire crest section may be jeopardized. To buttress the crest area of the repair (both during and after construction), a toe berm was incorporated into the design. The toe berm was constructed using irregular shaped (but not slabby) stone carefully placed to minimize voids and provide maximum stone-to-stone contact (interlocking). The anticipated stability of each armor stone used in the toe berm is achieved independently. If one or several armor units are displaced from the toe berm, the overall stability of the toe berm is not compromised. The toe berm is also expected to act as an energy dissipater for waves (before waves impact the crest section) and as a bench on which displaced armor stone comes to rest (maintains a functional cross-section, rather than allowing displaced stone to fall down slope).