基于SPH深度积分模型的海底滑坡数值分析

发布时间：2018-02-04 03:42

本文关键词： 滑移速度滑移距离 SPH深度积分法摩擦流变模型侵蚀效应　出处：《大连理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：海底滑坡会对海洋工程结构物造成严重破坏。海底滑坡一般表现为高流速、长距离的滑动,即使在深海陆坡很平坦的区域也有可能发生滑坡,滑移体会对流径上的海底管线等设施产生强烈的冲击,直接危害海洋工程设施的安全,造成巨大的经济损失。本文主要研究海底滑坡的流动过程,模拟了在不同水深、坡度、接触摩擦系数、侵蚀率工况下的海底滑坡,对比了各个工况的滑移速度、滑移长度以及沉积物厚度时程曲线,并整理了最大滑移距离、最大速度等信息,讨论变化规律。研究成果可为海底滑坡灾害预警和海底管线路由选址提供技术参考。首先,本文系统地总结了海底滑坡的类型、诱发机制、海底滑坡的特征、海底滑坡和SPH深度积分法的研究概况。其次,详细介绍了SPH深度积分方法的基本理论、摩擦流变模型和侵蚀模型。海底滑坡需要考虑流动过程中滑移体与水体的相互作用,滑坡发生前滑移体的自由面受到的静水压力的作用及滑动后受到的动水压力的作用；接触摩擦系数随着滑移体固结和动水压力的改变而改变；被侵蚀、挟带的土体的惯性阻力会增加滑移体底部的剪切阻力。再次,采用SPH深度积分法和Bing程序模拟了海底滑坡,分析了计算结果。SPH深度积分法模拟了三维海底滑坡,并三维陆地滑坡进行了相比,直观展示了沉积物的滑移过程。最后,总结了数值模拟结果,探讨规律：水深对海底滑坡的最大滑移距离和速度的影响并不明显,但坡度、接触摩擦系数的变化影响明显；当侵蚀率达到10-4m-1以上时,侵蚀效应明显。SPH深度积分模型,计算简便,适于模拟海底滑坡。
[Abstract]:Submarine landslides can cause serious damage to offshore structures. Submarine landslides are usually characterized by high velocities, long distance slippages, and landslides can occur even in areas where deep sea slopes are flat. The slip experiences that the submarine pipeline and other facilities on the convection path have a strong impact, directly endanger the safety of the marine engineering facilities and cause huge economic losses. This paper mainly studies the flow process of the submarine landslide, and simulates the flow process of the submarine landslide at different water depths and slopes. Under the condition of contact friction coefficient and erosion rate, the slip velocity, slip length and sediment thickness time history curve of each condition are compared, and the information of maximum slip distance and maximum velocity are sorted out. The research results can provide a technical reference for submarine landslide disaster warning and submarine pipeline routing location. Firstly, this paper systematically summarizes the types of submarine landslide, inducing mechanism, characteristics of submarine landslide, The basic theory of SPH depth integration method, friction rheological model and erosion model are introduced in detail. The effect of hydrostatic pressure on the free surface of the sliding body before the landslide occurs and the effect of the hydrostatic pressure on the sliding body; the contact friction coefficient changes with the change of the slip body consolidation and the dynamic water pressure; it is eroded, The inertia resistance of the entrapped soil will increase the shear resistance at the bottom of the slip body. Thirdly, the submarine landslide is simulated by SPH depth integration method and Bing program, and the three-dimensional submarine landslide is simulated by the SPH-depth integration method. Finally, the numerical simulation results are summarized, and the law is discussed: the influence of water depth on the maximum slip distance and velocity of submarine landslide is not obvious, but the slope is not obvious. The influence of contact friction coefficient is obvious, when the erosion rate is above 10-4m-1, the erosion effect is obvious. SPH depth integral model is easy to calculate and is suitable for simulating submarine landslide.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P642.22;P736

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