景观斜坡堤和护岸的越浪与爬坡的模拟研究

发布时间：2018-03-09 16:49

本文选题：越浪　切入点：爬坡　出处：《大连理工大学》2017年博士论文　论文类型：学位论文

【摘要】：随着滨海旅游和海洋休闲娱乐需求的不断增长,兼具防波、景观、亲水功能的景观斜坡堤和护岸也得到了极大发展。景观斜坡堤和护岸结构有别于常规结构,发生越浪时,堤顶越浪流、护岸顶爬坡流及堤后次生波与常规的也不尽相同。越浪流、爬坡流对堤顶、护岸顶的建筑、设施甚至人身安全造成威胁,而堤后次生波也严重影响着堤后水域船舶泊稳。因此,开展景观斜坡堤和护岸的越浪与爬坡研究,正确预测、评估堤顶越浪流、护岸顶爬坡流及堤后次生波等,对景观斜坡堤和护岸工程建设及海滨旅游发展具有重要的现实意义。本文分别利用物理模型试验和数值模拟方法对景观斜坡堤和护岸的越浪与爬坡进行了研究。主要研究内容如下:提出计算精度和稳定性改进的SPH方法(SISPH)。首先分析了常用SPH方法模拟较大波幅波浪较长时间传播时存在的问题,在此基础上,分别从光滑核函数和支持域内相邻粒子分布情况两方面对常用SPH方法进行改进,提高了 SPH方法数值计算的精度和稳定性。进一步,建立了增强型动态边界条件(EDBC),从而提出稳定性增强型SPH方法(SISPH),实现了较大波幅波浪较长时间传播过程的准确模拟。针对堤顶具有一定宽度且光滑不透水的景观斜坡堤、顶部具有缓坡同样光滑不透水的景观护岸开展越浪与爬坡的物理模型试验研究。试验采用规则波和不规则波,分别在不同斜坡堤和护岸顶超高及不同斜坡堤堤顶宽度下,开展越浪和爬坡的物理模型试验,并对试验结果进行系统的分析研究。首先,详细分析了越浪量与堤顶宽度的关系,研究了堤顶宽度对越浪量影响的机理,并给出了越浪量沿堤顶宽度衰减系数的计算式。其次,探讨了越浪流厚度与堤顶前沿处平均越浪量的关系,并分析了越浪流的沿程变化规律。再次,对堤后次生波波高系数与越入堤后平均越浪量的关系进行研究,得到次生波波高系数的计算式,并利用频谱分析研究了堤后次生波的特性。最后,对护岸顶爬坡流厚度、最大爬坡距离与护岸顶前沿处越浪量的关系进行探讨,分析了爬坡流厚度沿程变化规律,给出了最大爬坡距离和爬坡流厚度的经验计算式。建立了景观斜坡堤和护岸的越浪与爬坡的数值模拟计算模型。该模型联合使用EDBC边界条件和改进的排斥力边界条件(RBC),实现了波浪传播、越浪流或爬坡流的准确模拟。同时,建立了一个适用于SPH方法的域内造波法,有效消除了较强非线性波浪的二次反射。应用所建立的数值模拟计算模型,对景观斜坡堤的越浪和护岸顶波浪爬坡进行了较长时间的数值模拟,并对数值模拟结果与物理模型试验结果进行了对比。结果证明,本文建立的数值模型可以较好地模拟景观斜坡堤和护岸的波浪越浪和爬坡过程,为相关研究提供了一个很好的数值工具。
[Abstract]:With the increasing demand for coastal tourism and marine recreation and recreation, the slope dike and bank revetment, which have the functions of wave prevention, landscape and hydrophilicity, have also been greatly developed. The slope embankment and bank revetment structure are different from the conventional structure, and when the wave surges, the slope levee and revetment structure are different from the conventional structure. The creeping current at the top of the embankment and the secondary wave behind the embankment are different from the conventional ones. The surpassing current and the climbing current pose a threat to the building, facilities and even the personal safety of the top of the embankment, the roof of the revetment, and the secondary waves after the embankment. The secondary wave behind the embankment also seriously affects the stability of the ship in the water area behind the embankment. Therefore, the study on overrunning and climbing of the slope embankment and revetment is carried out to correctly predict and evaluate the surpassing current at the top of the embankment, the creeping current at the top of the revetment and the secondary wave after the breakwater, etc. It is of great practical significance to the construction of slope embankment and revetment engineering and the development of seashore tourism. In this paper, the overtopping and climbing of the slope embankment and bank revetment are studied by using physical model test and numerical simulation method respectively. The main contents of the study are as follows: the improved SPH method for computing accuracy and stability is proposed. Firstly, the problems existing in the simulation of the long time propagation of waves with large amplitude by using the SPH method are analyzed. On this basis, the common SPH method is improved in terms of smooth kernel function and distribution of adjacent particles in support domain, which improves the accuracy and stability of the numerical calculation of SPH method. An enhanced dynamic boundary condition is established, and a stable enhanced SPH method is proposed to simulate accurately the long time propagation process of waves with large wave amplitude. For the landscape slope breakwater with a certain width and smooth impermeability at the top of the embankment, a stable and enhanced SPH method is proposed. The physical model test study on surpassing and climbing of landscape revetment with gentle slope and same smooth impermeability at the top is carried out. The test adopts regular wave and irregular wave, under the conditions of different slope embankment and bank protection top super-high and different slope embankment top width, respectively. The physical model tests of surpassing and climbing were carried out, and the results were systematically analyzed. Firstly, the relationship between the surpassing volume and the top width of the embankment was analyzed in detail, and the mechanism of the influence of the top width on the surpassing was studied. The formula of the attenuation coefficient along the top of the embankment is given. Secondly, the relationship between the thickness of the surpassing wave flow and the average surpassing volume at the front of the top of the embankment is discussed, and the variation law of the surpassing wave flow along the top of the embankment is analyzed. The relationship between the coefficient of secondary wave height after breakwater and the average volume of wave overrun after entering the embankment is studied. The formula for calculating the coefficient of secondary wave height is obtained, and the characteristics of secondary wave behind the breakwater are studied by means of spectrum analysis. Finally, the thickness of the creeping current at the top of the revetment is studied. The relationship between the maximum climbing distance and the surpassing wave at the front of the revetment is discussed, and the variation law of the climbing flow thickness along the slope is analyzed. An empirical formula for calculating the maximum climbing distance and the thickness of the climbing flow is given. A numerical simulation model of the overtopping and climbing of the slope embankment and revetment is established. The model combines the EDBC boundary condition with the improved repulsive force boundary. The condition is RBC, and the wave propagation is realized. At the same time, an in-domain wave-making method suitable for SPH method is established, which effectively eliminates the secondary reflection of strong nonlinear waves. A long time numerical simulation was carried out on the overtopping wave of the slope embankment and the top wave of the revetment, and the results of the numerical simulation were compared with the results of the physical model test. The numerical model established in this paper can well simulate the wave surpassing and climbing process of the slope embankment and revetment in the landscape, which provides a good numerical tool for the related research.
【学位授予单位】：大连理工大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：U656

【参考文献】