无围堰条件下横沙浅滩接纳长江口深水航道维护疏浚土的可能性分析
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摘要
受流域来沙持续减少影响,长江河口拦门沙区域已普遍进入侵蚀状态,滨海湿地资源流失日趋明显。同时,长江口深水航道疏浚维护量也有所减少,疏浚土资源日趋宝贵。近年来疏浚维护量基本稳定在5 500万～6 000万m~3/a。利用航道疏浚土就近补给受侵蚀浅滩,可成为未来疏浚土资源化利用的重要方向。从培育生态滩涂角度出发,无围堰条件下的吹填上滩是需要研究的工艺选项。以横沙浅滩为例,借鉴淤泥质海床在波浪作用下动力响应的黏弹性模型和连云港外航道疏浚土实测流变特性参数,研究分析了淤泥海床在不同来波波高和不同浮泥密度下的波高衰减率,得到浮泥密度1. 20～1. 30 g/cm~3时消浪效果最大等结果。该思路和方法可为长江口航道疏浚土无围堰吹填工艺论证提供参考。建议对长江口航道疏浚土的动态流变特性等开展试验研究。
Due to the continuous decrease of sediments coming from upstream,the area of sediment blocking in the Yangtze estuary has generally entered the state of erosion, and the coastal wetland resources are losing obviously.At the same time,the amount of dredging maintenance in the Yangtze estuary deepwater channel has also been reduced,and the dredged soil resources are becoming increasingly valuable. In recent years,the maintenance volume of dredging has been basically stable at 55 million ～ 60 million m~3/a. The utilization of dredged soil in the channel to replenish the nearby eroded shoal can be an important direction for the utilization of dredged soil resources in the future.To foster the ecological intertidal zone,filling to the shoal without cofferdam is a process way requiring further research.Taking Hengsha shoal as an example,by referring to the viscoelastic model of the dynamic response of the silty seabed under the action of waves and the measured rheological characteristic parameters of the dredged soil in the outer channel of Lianyungang Port,the attenuation rate of the wave height of the silty seabed under different incoming wave heights and different floating mud densities was studied and analyzed,and the results of maximum wave dissipation effect when the floating mud density was 1. 20 ～ 1. 30 g/cm~3 were obtained.The ideas and methods of this paper can provide references for the filling process without cofferdam of dredging sediment from the Yangtze estuary deep-water navigation channel. It is also suggested to carry out experimental research on the dynamic rheological properties of dredged sediment from the Yangtze estuary deep-water navigation channel.
Due to the continuous decrease of sediments coming from upstream,the area of sediment blocking in the Yangtze estuary has generally entered the state of erosion, and the coastal wetland resources are losing obviously.At the same time,the amount of dredging maintenance in the Yangtze estuary deepwater channel has also been reduced,and the dredged soil resources are becoming increasingly valuable. In recent years,the maintenance volume of dredging has been basically stable at 55 million ～ 60 million m~3/a. The utilization of dredged soil in the channel to replenish the nearby eroded shoal can be an important direction for the utilization of dredged soil resources in the future.To foster the ecological intertidal zone,filling to the shoal without cofferdam is a process way requiring further research.Taking Hengsha shoal as an example,by referring to the viscoelastic model of the dynamic response of the silty seabed under the action of waves and the measured rheological characteristic parameters of the dredged soil in the outer channel of Lianyungang Port,the attenuation rate of the wave height of the silty seabed under different incoming wave heights and different floating mud densities was studied and analyzed,and the results of maximum wave dissipation effect when the floating mud density was 1. 20 ～ 1. 30 g/cm~3 were obtained.The ideas and methods of this paper can provide references for the filling process without cofferdam of dredging sediment from the Yangtze estuary deep-water navigation channel. It is also suggested to carry out experimental research on the dynamic rheological properties of dredged sediment from the Yangtze estuary deep-water navigation channel.
引文
[1]徐海根,虞志英,钮建定,等.长江口横沙浅滩及邻近海域含沙量与沉积物特征分析[J].华东师范大学学报(自然科学版),2013(4):42-54.
[2]虞志英,张志林,金鏐,等.长江口横沙浅滩挖入式港池与入海航道区域海床稳定性分析[J].华东师范大学学报(自然科学版),2013(4):55-71.
[3]呼和敖德,周显初,李家春,等.连云港淤泥质海床上波浪衰减研究:实验、观测及理论模型比较和评价[J].海洋工程,1994(2):68-77.
[4]樊社军,虞志英.淤泥质岸滩侵蚀堆积动力机制及剖面模式:以连云港地区淤泥质海岸为例[J].海洋学报(中文版),1997(3):66-76.
[5]周显初,王剑峰.水波在软淤泥底床上的衰减[J].海洋工程,1994(3):54-64.
[6]中国科学院力学所.连云港淤泥流变特性实验研究(课题报告)[R].北京:中国科学院力学所,2008.
[2]虞志英,张志林,金鏐,等.长江口横沙浅滩挖入式港池与入海航道区域海床稳定性分析[J].华东师范大学学报(自然科学版),2013(4):55-71.
[3]呼和敖德,周显初,李家春,等.连云港淤泥质海床上波浪衰减研究:实验、观测及理论模型比较和评价[J].海洋工程,1994(2):68-77.
[4]樊社军,虞志英.淤泥质岸滩侵蚀堆积动力机制及剖面模式:以连云港地区淤泥质海岸为例[J].海洋学报(中文版),1997(3):66-76.
[5]周显初,王剑峰.水波在软淤泥底床上的衰减[J].海洋工程,1994(3):54-64.
[6]中国科学院力学所.连云港淤泥流变特性实验研究(课题报告)[R].北京:中国科学院力学所,2008.
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