摘要:
介绍了中外4个基岩陡斜海岸的养滩案例,说明基岩海岸水下坡一般较陡,水深较大,近海波浪未经底摩擦消能过程就逼近海岸,实行一次性卷跃破碎,强烈侵蚀海岸,塑造侵蚀地貌或在海蚀崖下高潮线附近沉积窄而薄的短裙式海滩。在这种海滩上进行开敞式抛沙养滩,往往难以成功,以致连年抛沙,连年被流失光。我国曾有一些养滩工程经历过该类沙流失干扰。按照丁坝与连续离岸潜坝组合或丁坝与平行双岸外潜坝组合模式,可以阻挡人工向前滨滩面所抛沙的外流,并能有效地消散岸外波能和阻挡沿岸移沙,保证人工抛沙养护海滩的扩宽和稳定。证明采取特定的硬工程组合可以在基岩陡斜海岸上构筑宽阔的人造海滩。
关键词:
-
基岩陡岸
/
-
人造海滩
/
-
丁坝
/
-
岸外潜坝
Abstract:
This paper introduces 4 domestic and oversea cases of nourishment at steep rocky beaches, where the coast, which faces deep water, is steep. In such cases, offshore waves approach the coast without bottom friction and energy dissipation. As a one-off breaking, they strongly erode the coast, and create erosional landforms without sediment or with a narrow skirt beach near the high tide line under the sea cliff. It is hard to carry out open sand nourishment at such a beach. Some of our domestic nourishment projects were suffered from the severe loss of sand. We made introductions in this paper to the model of combining the groins and continuous offshore submerged-dikes and the model of combining the groins and double parallel offshore submerged-dikes, which may stop the loss of sand nourished at foreshore flow-out, and promote the dissipation of the offshore wave energy and then stop the littoral drift to protect the nourished beach from erosion. It proves that it is possible to construct a broad artificial beach at a steep rocky beach with the support of specific combination of hard structures.
下载: