【作者】 饶永红；

【导师】 俞聿修；

【作者基本信息】 大连理工大学 ， 港口、海岸及近海工程， 2011， 博士

【摘要】 河口海岸地带是陆地和海洋的交汇处,为实现经济的可持续发展,需要实施的工程措施包括河口治理工程、港口工程、岸线防护工程和环境保护工程等。河口治理工程中,研究河口潮流物理模型的验证方法并利用该模型进行拦门沙航道整治方案的优化研究是河口海岸工程的重要问题。港口工程在设计时需利用波浪物理模型试验或数值模拟确定港池水域平稳度,为港区平面配置提供技术支持。以广利河口为例,研究了缓混合海相河口潮流物理模型的验证方法,总结了口门潮位、河口段潮位对模型扭曲水道长度、加糙方法、加糙范围和潮汐箱控制站潮型曲线等主要模型参数的响应规律,并以此为核心内容,提出了该类型河口的模型验证方法,提高了模型验证的效率和精度。以广利河口为例,系统分析了缓混合海相河口的水文泥沙和河床演变特征,指出粉沙质河口拦门沙航道整治须同时采取疏浚和建设导堤的工程措施。由此,通过潮流定床模型试验,首先研究了拦门沙航道轴线的四种基本方向对河口的纳潮量、潮位和拦门沙航道流速分布的影响,确定了最佳方向,与现场调研结果相符。接着,以此方向为基础进行优化,研究了航道过水断面面积、导堤顶高程组合、航道拐弯段环流、口门布置形式等对航道内流速、流向和局部流态的影响,并采用局部动床定性试验验证了工程方案流速、流态分布合理,基本能维持航道设计通航水深并满足设计船型的航行条件。最后,研究得出工程方案各段导堤对维持航道水深的贡献存在大的差异,建议根据贡献大小确定施工顺序。港内水域平稳度的研究有两类方法,一是波浪物理模型试验,二是波浪数值模拟。研究中经常遇到造波线和等深线夹角较大以致造波线上各点波要素的差异不能忽略的情况,此时边界条件的确定成为难点：对于单口门港池,物理模型试验采用口门处设置一个验证点的“一段造波法”,通过“凑波”确定边界条件是可行的,但对于多口门港池,这种方法中验证点的位置对试验结果存在较大的影响；数值模拟中,某些模型(如目前被广泛应用的Mike21Boussinesq方程模型)不能给出符合实际情况的边界条件。本文通过实例论证了Mike21的Boussinesq方程模型不宜将波要素验证点设在作为造波边界的造波线上,而应借鉴物理模型试验的“凑波”方法,将验证点设在拟建口门处,在原始地形上对边界条件进行修正。接着,对多口门港池,提出了各口门分别设置验证点的“分段造波法”,可以据此对数值模拟的边界条件进行的修正,并对物理模型试验解决同样问题采用“一段造波法”的做法提出了改进的建议。最后,将“分段造波法”应用于两口门港池、造波线和等深线交角近90°的情况,给出了合理的计算结果。更多还原

【Abstract】 A river-mouth or coastal area is the confluence of land and ocean. Necessary engineerings need to be carried out for for river-mouth harnessing, harbor, shoreline protection, environment protection and so on. In river-mouth harnessing engineering, it is important to study the verification methods of a river-mouth physcial tide model and to optimize the regulation plan of the navigation channel at a river-mouth bar by the model. For harbor engineering, as a technical support for its layout design, harbor water tranquility needs to be validated by a physical model or a numerical model.The detailed verification methods of river-mouth physcial tide model are studied based on Guangli river mouth which is a typical mild mix and marine deposition river mouth. The responses of the dominant model parameters to the tide levels at the river-mouth and the tide-current reach are included. Here the dominant model parameters consist of model length of the upper curved channels, methods of roughness, roughness areas and the tide-level curve at the control station ahead of the tide box. Taking the response laws as the important contents, a model verification method is given to improve its efficiency and precision.Taking Guangli river mouth as an example, system analyses of hydrometeorology, sediment and riverbed evolution of the one with mild mix and marine deposition are done. It is suggested that dredging and guard jetties should be applied simultaneously while regulating the navigational channel of a river-mouth bar with microscopic sand. By fixed bed tide model test, firstly four alternative channel directions are tested to study their effects on tide prism, the tide levels and the velocity distribution in the navigational channel of the river mouth bar. And among them, the best direction, which is consistent with the surveyed facts, is decided. Secondly, on the basis of the best direction, the effects on the velocity, flow direction and local flow pattern in the navigational channel exerted by its area of wetted cross section, the elevation of jetties, the swirling flow at the round segment of the navigational channel, the layout form of the jetty outlet are studied. The results of the local movable bed test also show that the velocity and the flow pattern along the channel of the final plan are reasonable which can basically maintain the channel water depth and satisfy the sailing conditions for designed ship. Finally, the studies show that contribution of each portion of the jetties for maintaining the channel water depth is greatly different. For a more economical investment, the jetty project should be divided into several portions and the construction schedule of each portion depends on its own contribution.When studying the harbor water tranquility with a physical model or a numerical model, a case is often confronted that the angle between the generation line and the isobath is so large that the differences of the wave climates along the generation line can not be ignored. For this case, the incident wave boundary is difficult to evaluate:(1) In a physical model, it is feasible to decide the incident wave boundary for one-entrance harbor by one verification point located at the entrance and’one-line generation method’; but for a multi-entrance harbor, this method is found that different position of the verification point will result in different harbor tranquility and the test error is so evident. (2) Some numerical models, such as the Boussinesq model of Mike21 which is widely used currently, cannot provide the natural wave distribution along the generation line.In order to solve this problem, firstly by several demonstrations, it is recommended that in the Boussinesq model of Mike21 the verification point should locate at the harbor entrance instead of locating on the wave generation line which is a model boundary, and the ’modulation method’ widely used in a physical model to determine the inputs for the wave generator according to the output should be introduced into Mike21 to modify the incident wave boundary of Boussinesq model on the original topography. Secondly, due to the deficiencies of a physical model and the Boussinesq model of Mike21, a multi-line wave generation method is proposed for a multi-entrance harbor, with each line generating waves at the same time independently and each entrance having its own verification point. Thirdly, this method is applied to a case that the harbor is designed with two entrances and the angle between the generation line and the isobath is near 90°. And the results are reasonable.更多还原