人工岛与多工程影响下的潮流动力响应特征

Responses of Tidal Currents to Artificial Island and Multiple Projects

人工岛常与连岛桥、海岸防护等工程构成复杂的人工岛工程系统,科学评估人工岛与多工程对周围海域潮流动力的影响,对海洋空间资源的开发与利用具有重要的指导意义。以海南三亚新机场工程为对象,建立了工程海域潮流数学模型,采用实测的潮位、流速、流向数据对模型进行了验证,模拟研究了人工岛、离岸潜堤和连岛桥等多工程作用下的潮流场响应特性。结果表明:工程海域的主体潮流特征为往复流,人工岛建设后其周围产生绕流,人工岛东北偏北和西南偏南两侧流速增大,西北偏西和东南偏东两侧形成缓流区,流速显著减小;弧形离岸潜堤修建后,其南北两侧由于绕流作用流速增大,弧内与东西两侧因阻水影响流速减小;连岛桥建设对潮流场的影响相对较小,主要表现为连岛桥背流侧的流速总体减小,而在人工岛与离岸潜堤的部分掩护区域,连岛桥则会导致流速有所增加。总体而言,在人工岛、离岸潜堤和连岛桥的共同作用下,工程海域潮流动力的时空变化将更为复杂,工程对不同位置处水流运动的影响规律存在明显的差异。

Artificial islands often constitute a complex engineering system with sea-crossing bridges,coastal protection and other projects.Scientific assessment of the impacts of artificial island and multiple projects on the tidal dynamics is of great guiding significance for the development and utilization of marine space resources.A hydrodynamic numerical model for Sanya new airport project in Hainan Province was established.The model was first validated against the observed data including tidal level,current velocity and current direction.Then,the responses of tidal currents to the artificial island,offshore submerged breakwaters and sea-crossing bridge were simulated and investigated.It is shown that the tidal currents in the project area have typical characteristics of reciprocating flow.After the artificial island construction,the tidal currents flow around it and the velocity on its north-northeast and south-southwest sides increases.Weak flow regions are formed on the west-northwest and east-southeast sides of the artificial island,where the current velocity decreases significantly.After the construction of the arc-shaped offshore submerged breakwaters,the current velocity on their south and north sides increases under the influence of the flow around.The current velocity inside and on the east and west sides of the breakwaters decreases due to the resistance to flow offered by structures.The impacts of the sea-crossing bridge construction on the tidal current fields are relatively weak.The current velocity generally decreases on the downstream side of the bridge,while increases in some regions sheltered by the artificial island and offshore submerged breakwaters.Overall,the temporal and spatial variation of tidal currents in the project area becomes more complex under the combined action of the artificial island,offshore submerged breakwaters and sea-crossing bridge.The influences of these projects on the tidal current patterns at different locations are various.