Research Of The Effect Of Coast Engineering On Nearshore Hydrodynamic Environment

Nearshore hydrodynamic environment is the great factor which brings the direct loads to the coast and marine structure,and is one of the most active and important studys in cosat and offshore engineers. So it is the great science value and operation significance to study the regularity of nearshore hydrodynamic factors. Nearshore hydrodynamic factors include wave,tidle current,tide,and corresponding sand movement etc. The hydrodynamic environmental of coast engineering are very complicated, at present, it's very hard to coupling all factors. In many research methods, the numerical model is one of the fastest and most economy ways,so it is the most important way to study the movements of large area hydrodynamic factors.Basing on estuary and coastal hydrodynamic theory, sediment transport theory,wave theory and numerical method, this paper presents a two-dimensional current, sediment transport modle and a wave numerical model, deformation module. The hydrodynamics module is solved with the alternating directional implicit (ADI) algorithm to obtain the water level and the current velocity. In the sediment transport module, a splitting technique is used to solve the sediment transport equation. And several sediment aggradation experiential formulas are analysed. The wave modle is based on mide slope equation.The numerical model is tested in Zhejiang Taizhou Jinqing fishing ports project. The tidal currents are compared with field data measured at locale. This paper analyzes the change of tide current field and the influence of sand silt before and after engineering, and simulate the wave transformation considering allied refraction and diffraction of Jinqing area.Through the application that use the numerical model for simulating engineering condition, the result is shown that this method could reflect the real condition better and provide reference for later numerical simulation.