The Numerical And Experimental Application Research Of Equilibrium Profile Design In Beach Nourishment

Beach nourishment is a popular shore protection measure around the world in recent years. The Twelfth Five-year Plan for National Economic and Social Development stresses that more emphases should be put on shore protection and coastline restoration. It is suggested that more attention should be paid on the summarization and assessment of the theories and techniques on beach nourishment. The reasonableness of design profiles for beach nourishment determines the adaptability of nourished beach to the hydrodynamic conditions of the site. It is strongly emphasized that the influence of design factors to beach stability should be analyzed from hydrodynamic view.Firstly, the development of beach nourishment method is reviewed in and abroad China. Also, the state-of-the-art of Equilibrium beach profile model, numerical and physical experiment study in beach profile evolution are reviewed in this article. The models and design methods of shoreline and profile morphology for beach nourishment is discussed.The response of different design proposals is simulated under various wave and tide condition to assess the influence of different design factors, such as median diameter of filled sand, beach berm width, beach berm height to profile stability. Besides, the numerical study of profile evolution with sheltering submerged breakwaters and revetments is carried out to assess the sheltering effects of breakwaters with different top elevations, top width and distance from the shore. The nourished shoreline change after several years is simulated by means of one-line model which is widely used in shoreline evolution. Based on the evolution results, the rationality of shoreline layout is evaluated.Furthermore, the beach profile and shoreline stability is studied based on physical experiment. For one thing, both cross-shore and long shore sediment transport is included in physical model. For another thing, the wave refraction, diffraction, reflection are more close to real in physical model compared to numerical model study. The proven experiment is carried out to validate model similarity first. After this, artificial beach profile and shoreline stability experiment is carried out to study the response of nourished beach under different wave and water level conditions and the features of near shore sediment transport.