Practical Experience in Analysis and Design of Perforated Vertical Wall Breakwaters in Various Physical Conditions

Two case studies are presented on perforated (porous) breakwaters that have been analyzed, designed, and constructed at Port facilities in Busan, South Korea and Port of Oakland, CA, United States. Motivation for the design and installation of these structures was driven by challenging soil conditions as well as a desire to modify wave reflection/transmission characteristics of the structure and the site. This paper discusses the analysis, numerical modeling, physical modeling, design, construction and po st-project monitoring performed for these two perforated breakwaters. Case Study 1 describes the Coast Guard and Cruise Terminal Pier at Busan, South Korea that was designed to provide moored vessels with protection from swells and wind-waves with periods ranging from 7 to 15 seconds in a depth of 12 meters. The final breakwater cross-sectional configuration was a perforated three-wall system with varying wall spacing and wall porosity. Transmission and reflection coefficients from the physical model satisfied the project design criteria. Case Study 2 describes the breakwater and fill containment structure at the Middle Harbor Enhancement Area, Port of Oakland, CA (USA). The breakwater was constructed to contain fill from the Port of Oakland’s 50-ft Dredging Project that was placed in order to create eelgrass habitat.