非线性波浪作用下浅海堤防受力及稳定性研究

发布时间：2018-03-30 06:52

本文选题：非线性波　切入点：堤防工程　出处：《中国海洋大学》2014年硕士论文

【摘要】：浅海堤防工程保护着沿海地区免受波浪潮流的侵袭，，但近年来全球气候变暖、海平面上升、风暴潮等自然灾害的频发，严重威胁浅海堤防工程的安全和稳定性。堤防工程破坏事故的时有发生对沿海的国民经济造成了巨大的损失。因此，堤防工程的安全和稳定标准值得进一步深入探究。随着计算流体力学的迅速发展，应用数值波浪水槽进行波浪与结构物的作用研究成为了近年来的前沿研究课题之一。本文对通过数值模拟的方法对浅海堤防的受力及稳定性进行了进一步研究，对堤防工程的安全建设和防护提供了一定的参考价值。首先利用流体力学分析软件Flow-3D，基于粘性流体假设和自由表面追踪的VOF方法，结合RNG k紊流模型，采用有限差分法求解Navier-Stokes方程，并进行二次开发，用椭圆余弦波模拟浅水波，建立一个主动吸收式的造波边界，结合孔隙结构的消波边界，建立了无反射的二维非线性波浪数值水槽，并验证了该数值水槽造波的有效性。接着在该波浪数值水槽的基础上进一步建立了浅海堤防数值模型，通过对不同工况下单堤和复式海堤两种断面受力的数值模拟和试验对比，并对堤面上最大波压力的分布和变化规律进行分析，验证了该浅海数值模型的可靠性。然后对不同戗台位置、戗台宽度及上下坡坡度的复式海堤进行了数值模拟，分析了戗台位置、戗台宽度及上下坡坡度对海堤结构受力的影响，得到了一些有益的结论。最后从力学本质建立了斜坡堤护面块体的失稳图式，对护面块体的波浪作用力进行分析，考虑堤坡坡度、堤前相对水深、堤前波坦三个方面对最大波浪负压力的影响，得到斜坡堤上法向最大相对波浪负压力沿堤面分布的经验表达式，进而从力的角度得到护面块体稳定重量的计算公式；同时确定了斜坡堤堤面上最不利受力区域的范围，对工程应用具有一定的指导意义。
[Abstract]:Shallow water levees protect coastal areas from waves, but in recent years global warming, sea level rise, storm surges and other natural disasters have occurred frequently. It is a serious threat to the safety and stability of the shallow water levee engineering. The breakage accident of the levee project has caused huge losses to the national economy of the coastal area from time to time. The standards of safety and stability in embankment engineering deserve further exploration. With the rapid development of computational fluid dynamics, The application of numerical wave flume to the study of the interaction between waves and structures has become one of the frontier research topics in recent years. In this paper, the force and stability of shallow water dikes are further studied by numerical simulation. It provides a certain reference value for the safety construction and protection of embankment engineering. Firstly, the fluid mechanics analysis software Flow-3D, VOF method based on viscous fluid hypothesis and free surface tracing, combined with RNG k turbulence model, is used to solve the Navier-Stokes equation with finite difference method, and the elliptical cosine wave is used to simulate shallow water wave. An active absorbing wave boundary is established and the wave absorbing boundary of pore structure is combined to establish a two dimensional nonlinear wave numerical flume without reflection. The effectiveness of the wave generation is verified. Then the numerical model of shallow water embankment is established on the basis of the wave numerical flume. The distribution and variation of the maximum wave pressure on the surface of the breakwater are analyzed, and the reliability of the model is verified. Then, numerical simulation is carried out on the multiple embankments with different dike positions, dike width and slope gradient, and the influence of the position of the dike, the width of the dike and the slope of the upper and lower slope on the stress of the seawall structure is analyzed, and some useful conclusions are obtained. Finally, according to the mechanics essence, the instability diagram of slope embankment surface block is established, and the wave force is analyzed. The influence of slope degree, relative water depth in front of embankment and wave tan in front of breakwater on the maximum wave negative pressure is considered. The empirical expression for the distribution of negative normal relative wave pressure on the slope embankment is obtained, and the formula for calculating the stable weight of the block on the slope embankment is obtained from the angle of force, and the range of the most unfavorable force area on the slope embankment surface is determined. It has certain guiding significance for engineering application.
【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U656.314;TV139.26

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