南海吹填岛礁护岸防波堤在台风天气中极端波浪冲击下的稳定性研究

In recent 3 years, totally 7 coral reef islands have been constructed in the way of reclamation by China in the South China Sea, which formed an effective strategic pivot when protecting the integrity of territory. This project is important and strategic for our China. However, the South China Sea is area where typhoons and tropic storms are frequently generated, or pass in each year. As a result, the stability of these revetment-breakwater on these reclaimed coral reefs is greatly threaten under the impact of huge ocean waves in the climates of typhoons or tropic storms. For the problem of the stability of these revetment-breakwater on these reclaimed coral reefs, the following three works will be conducted. (1) Development of a constitutive model for the calcareous sands in South China Sea considering the particles breakage. (2) Conducting some physical modelling wave flume tests with large-scale (1:10). (3) Application of the coupled numerical model FSSI-CAS 2D/3D for wave-structure-seabed interaction to the problem of the stability of these revetment-breakwater. Based on the test results from wave flume tests, as well as the computational results from FSSI-CAS 2D/3D, the characteristics of dynamic response of revetment-breakwater on reclaimed coral reefs to extreme ocean waves in typhoons or tropic storms climate will be analyzed. Furthermore, the stability of the revetment-breakwater on reclaimed coral reefs will be quantitatively evaluated. The core purpose of our work is to make some foundation for the establishing the technical method system for the stability evaluation of the revetment-breakwater on reclaimed coral reefs; and provide ocean engineers with a typical successful case application. All these works will promote the technology of stability evaluation of the revetment-breakwater on reclaimed coral reefs in China to a new level.

近3年来，我国在南海采用吹填的方式建成了7座珊瑚岛，形成了有效的战略支点，是国家的战略性工程。然而，南海是一个台风、热带风暴多发的地区；台风、热带风暴天气中巨大的海洋波浪冲击作用对岛礁吹填体的护岸防波堤的稳定性构成极大的威胁。针对岛礁护岸防波堤的波浪稳定性问题，本项目将发展考虑颗粒破碎的岛礁钙质土的本构模型，并开展1：10大比尺水槽物理模型试验，以及应用具有自主知识产权的波浪-结构物-地基相互作用耦合计算模型FSSI-CAS-2D/3D来系统研究岛礁护岸防波堤在50年、100年一遇的极端波浪作用下的动力响应特征，并评价其稳定性。本研究的目的是期望为建立评价岛礁防波堤波浪稳定性的技术方法体系奠定基础，并提供典型应用案例，促进我国在评价岛礁防波堤波浪稳定性方面的技术进步。

自2013年以来，我国在南海采用吹填方式建成了7座珊瑚岛，形成了有效的战略支点，为维护国家海洋领土完整起到了重要作用，是国家的战略性工程。然而，南海是一个台风、热带风暴多发的地区；台风、热带风暴天气中巨大的海洋波浪冲击作用对岛礁吹填体的护岸防波堤的稳定性构成极大的威胁。针对岛礁护岸防波堤的波浪稳定性问题，本基金项目开展了以下三个方面的工作：（1）开展了1：10大比尺水槽物理模型试验，（2）研究了南海岛礁近岸极端波浪运动演化过程及其水动力特征，（3）研发了具有国产自主知识产权的波浪-结构物-地基相互作用耦合计算模型软件FssiCAS。通过系统的研究工作，系统认清了岛礁防波堤在极端波浪冲击下的动力响应特征，掌握了岛礁近岸波浪的运动演化过程以及数值仿真方法，采用自主研发的耦合计算模型FssiCAS计算分析认为岛礁防波堤在设防条件下的稳定性可以得到保证。本研究建立了评价岛礁防波堤波浪稳定性的技术方法体系，为南海岛礁结构物的动力稳定性评价、设计优化和后期维护提供了分析平台和理论支持。