炸礁工程悬浮物在强潮海域扩散的数值计算研究

发布时间：2018-01-04 04:30

本文关键词：炸礁工程悬浮物在强潮海域扩散的数值计算研究　出处：《浙江大学》2016年硕士论文　论文类型：学位论文

【摘要】：舟山背靠长江三角洲等辽阔腹地和沪、杭、甬等大中城市群,面向太平洋,是长江流域和长江三角洲对外开放的海上门户和通道。舟山海域辽阔,岛屿众多,拥有得天独厚的深水港湾,独特的岛屿陆地,四通八达的深水航道,众多的锚地和宽阔的深水港池。随着长三角经济一体化、宁波舟山港港口一体化的不断推进、上海国际航运中心洋山港区建成以及舟山江海联运服务中心的设立,舟山区位优势不断提升,港口岸线资源也逐渐得到开发。本文研究海域位于虾峙门水道与条帚门水道之间的西白莲山岛附近,西白莲山岛位于舟山市普陀区虾峙岛的西北,该岛港口航道资源优势明显,但其周围暗礁众多,船舶航行时易发生触礁危险,使得该岛岸线资源开发受到限制。为消除暗礁对通航船舶的影响,某用海单位考虑对西白莲山岛西侧几处暗礁进行清理,然后再将西白莲山岛西侧海域用于港口开发。经初步查明,礁石为凝灰岩,因此只能采取先钻孔爆破将其解体,再用挖泥船等设备对礁渣进行清理的施工方案。炸礁和清渣施工工艺将不可避免产生高浓度的悬浮物,悬浮物的扩散对周围海洋生态环境产生一定影响,本文借助于二维潮流泥沙数值模拟,对炸礁和清礁产生的悬浮物扩散范围进行预测,预测结果可为该炸礁工程的环境影响评价提供理论依据,并为工程可行性研究提供参考,因此本文的研究具有一定的实际意义。本文以岛礁众多潮流复杂的舟山海域为例,基于Delft3D软件建立了适合研究该海域的潮流数学模型,并利用该模型模拟了炸礁和清礁过程中悬浮物的输移过程,主要研究成果及结论如下：第一：悬浮物数值模拟运算结果较为直观的反映了炸礁和清礁过程中,涨落潮在不同时刻悬浮物的扩散情况,包括浓度增值扩散范围和扩散距离,得出了在涨落潮时刻平均流速为1m/s的强潮海域,炸礁产生浓度增值0.010kg/m3以上悬浮物对周围海域的影响时间约为0.5h,影响范围为顺流方向200m的模拟结论。而清礁产生悬浮物对周围海域影响范围较小、时间较短。为减少炸礁对周围海域的影响,建议施工单位采取平潮间隙进行爆破施工,而清礁全潮都可以施工。第二：悬浮物扩散速度与潮流有较大关系,而与源强大小关系不大。在岛礁众多的强潮海域,由于受到漩涡潮流的影响,悬浮物的扩散速度反而会出现变缓现象。
[Abstract]:The hinterland of Zhoushan back in the Changjiang River Delta and Shanghai Hangzhou Ningbo, vast, and other large and medium-sized city group, facing the Pacific Ocean, is the Yangtze River and the Yangtze River Delta Open Sea portals and channels. The vast waters of Zhoushan, numerous islands, with richly endowed by nature deep-water harbor, unique island land, deep waterway connected, many roads the broad and deep water port pool. Along with the economic integration of Yangtze River Delta, Ningbo Zhoushan port integration continues to promote the establishment of building Shanghai international shipping center Yangshan Port and Zhoushan Jianghai transport service center, the location advantage of Zhoushan rising, harbor shoreline resources have gradually been developed. In this paper, the study area is located in the vicinity of Xiashimen channel between with a broom the west gate waterway of Lotus Mountain Island, west of Lotus Mountain island is located in Zhoushan city Putuo District xiazhimen the northwest of the island, the island harbor resources advantage is obvious, but its surrounding Many reef ship ran aground, prone to danger, making the development of coastal resources of the island is restricted. In order to eliminate the influence of the reef ship, with a clean up on the west sea units into the lotus island on the west side of a few rocks, and then west to the island on the West side of lotus sea port development. After a preliminary investigation, the rocks for tuff, it can only take the first drilling blasting dismantling it, and dredge equipment construction scheme of clean reef reef and slag slag. The construction process will inevitably produce high concentration of suspended sediments and suspended solids diffusion have a certain impact on the ecological environment around the sea, with the help of two dimensional numerical tidal sediment simulation of suspended substance on reef and reef clear diffusion range prediction, the predicted results can provide a theoretical basis for the environmental impact of the reef project evaluation, and project feasibility study. For reference, so this study has some practical significance. In this paper, many complex tidal waters of Zhoushan island as an example, based on Delft3D software was established for the study of tidal flow mathematical model of the sea, and the model was used to simulate the transport process of suspended reef and reef cleaning process, the main research results and conclusions are as follows SS: First: the numerical simulation results is more intuitive to reflect the reef and reef in the process of diffusion of the tide at different times of suspended substances, including the concentration of added diffusion range and diffusion distance, obtained in the ebb time average velocity is 1m/s strong tidal waters, reef time concentration of added 0.010kg/m3 the above suspension effect on the surrounding sea area is about 0.5h, the influence scope of the simulation conclusion downstream 200m. Due to a smaller range of influence of suspended substance on the waters around the reef is relatively clear. Short. In order to reduce the influence of the waters around the reef, the construction units taken by blasting of slack water gap, and clear the whole tidal reef can construction. Second: suspended solids diffusion velocity and the trend has great relationship, and has little relation with the source strength. In the strong tide of reef numerous, influenced by the vortex flow the diffusion velocity of suspended solids but there will be a slow phenomenon.

【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U616.24;X55

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