Application and Experiment of the Theory of Headland-Bay Equilibrium Coast in the Design of Artificial Beach Shoreline

Coastal scientists and engineers are constantly trying to quantify the ideal bay shape using mathematical formulas. Since the 1980s, a large number of achievements have been accomplished and various empirical models have been obtained. This article is based on the theory of equilibrium coastal development in the headland-bay and takes an artificial beach forming part of Rizhao Port's "Return to Sea" project in Northern China as an example to explore the selection of beach protection schemes. The influence of different forms of plan layout on the shape of the equilibrium shoreline is compared, and the scheme is further validated using physical model testing methods. The following results are obtained: (1) a suitable protection scheme and its corresponding beach equilibrium shoreline shape are recommended, (2) a reasonable maintenance cycle is proposed, and (3) after 27 months of implementation of the artificial beach, the monitored sediment loss is less than 10% of the total amount, meeting the design purpose. This confirms the effectiveness of the research results in artificial beach protection engineering and equilibrium shoreline design, achieving good economic, social, and ecological environmental benefits, and with broad prospects for promotion and application. The results can also provide reference and guidance for subsequent coastal engineering evaluation, improvement, and construction.