【作者】 汪鹏；

【导师】 卢金友；

【作者基本信息】 长江科学院 ， 水力学及河流动力学， 2008， 硕士

【摘要】 随着社会经济的快速发展,河道岸线开发利用活动日益增多。岸线开发利用工程的修建会对河道水沙运动及河床变形的产生影响,进而可能对河势、防洪等带来不利影响。以往对单个工程的影响进行了评价,对多个工程的累积影响很少进行研究。本文采取概化模型试验和数学模型计算分析研究了工程群对河道水流运动的累积影响,获得以下主要成果。(1)概化模型试验结果表明,码头群对水流的影响不能简单的看作单个码头影响的线性叠加,而是与桩和码头的间距、数量、形态等因素有关。桩间距越小,码头越密集,数量越多,其透水效果越差,水槽过水时在码头群前沿形成“水墙”,其透水率相对于单个码头的透水率大大减小,糙率迅速增大。(2)武汉河段岸线利用工程影响数学模型计算结果表明,桥梁、码头群的建设对河道水位和流场会产生叠加影响。当工程达到一定密度后,河道的壅水值较单个工程几乎增大一个数量级。计算结果显示,武汉河段的码头密度宜小于1.33座/km,如果大于这个密度,则会造成工程群的叠加效应。(3)单个工程对河势、防洪的影响有限,但系列工程的累积影响不容忽视。每个河段的岸线开发利用应以规划为指导,而且应针对整个河段进行总体论证。在进行涉水工程防洪评价时,必须考虑河段内的其它工程及累积影响。岸线开发利用工程的密度要充分论证,以不构成累积影响为原则。目前长江岸线利用工程存在密度过大的情况,应作相应调整,对影响大的工程进行改造或搬迁。更多还原

【Abstract】 As society and economy on the riverside regions developed faster and faster, the bank lines-developing projects were growing quickly. These projects in the riverway, would increase the water level, change the velocity of flow and transform the river regime. If the projects were not programmed or constructed reasonably, the projects would be too concentrated. Subsequently, the safety of flood control would be threatened. In the past, the flood control evaluation had been taken only in individual project, but hardly in projects groups, which would generate overlaying effect.In the paper, the generalized physical model experiment and the two-dimensional hydrodynamic mathematical model were applied in research of overlaying effect caused by [rojects group. The main achievements werer as follows:(1) The reault of generalized physical model experiments showed that the influence of projects group can’t be considered as the linal summation of individual docks, but connect with space, number of the piers and docks and so on. Along with the increase of docks and decrease of space between piers, the ratio of water penetrating would diminish seriously. The water barrier effect appeared, accordingly, the sink roughness raised.(2) The hydrodynamic mathematical model showed that the bridges and docks would generate overlaying effect to the water level and veolicity. When the density of docks was big enough, the increase of water level will rise seriously. Also, the calculating results showed that in Wuhan reach, the reasonable density of docks groups would be 1.33 per km. If the density was bigger than that, the overlaying effect would appeare.(3) The influence of individual projects to flood control and river rigem was limited, but influence of series projects makes a big difference. The bankline-developing projects should be guided by the program, and also the whole reach should be evaluated. When a water involved projects was taken a flood control evaluation, influence of other projects in the same reach should also be considered.It is proposed that in the future, the projects are programmed to avoid overlaying effect. As for the unreasonable built docks, it is suggested to be transformed or dismantled, for the sake of flood control safety.更多还原