波致砂土海床剪切与液化破坏特征对比研究

发布时间：2018-02-14 10:51

本文关键词： 波浪砂土海床剪切破坏液化　出处：《中国海洋大学学报(自然科学版)》2017年07期 　论文类型：期刊论文

【摘要】：波浪作用下海床的稳定性直接影响着海洋构筑物的安全。目前在波土相互作用的研究中,虽然较多地涉及到对海床液化或剪切破坏的分析,但缺乏不同海床计算厚度和饱和度等条件下二者破坏特征的对比研究。本文基于波浪作用下海床应力的解析解,对砂土海床的剪切破坏和瞬态液化破坏特征进行了详细研究和对比。结果分析表明,对于波浪作用下不同饱和度的砂土海床,其剪切破坏深度随海床计算厚度的增加表现为3种变化模式,而其液化深度随海床计算厚度的增加则只表现为1种变化模式。相比非饱和砂土海床,饱和砂土海床计算厚度较小时才可能发生液化,且其液化深度最小,但相同条件下对应的剪切破坏深度却最大。波浪作用下砂土海床存在一个最不稳定厚度,其数值约为(0.2~0.3)倍波长,此时海床最易发生破坏,且破坏深度较大。波浪作用下砂土海床的剪切破坏在波峰和波谷处均可能发生,而瞬态液化只发生在波谷位置,且其液化深度位于剪切破坏深度范围内。
[Abstract]:The stability of the seabed under the action of waves directly affects the safety of marine structures. At present, in the study of wave-soil interaction, although the analysis of liquefaction or shear failure of the seabed is mostly involved, However, there is a lack of comparative study on the failure characteristics of the two under different sea bed calculation conditions, such as thickness and saturation. This paper is based on the analytical solution of the stress of the seabed under the action of waves. The characteristics of shear failure and transient liquefaction failure of sandy seabed are studied and compared in detail. The shear failure depth varies with the calculated thickness of the seabed in three ways, while the liquefaction depth with the calculated thickness of the seabed shows only one mode of variation, compared with that of the unsaturated sandy seabed, the shear failure depth of the sea bed varies with the calculated thickness of the seabed, while the depth of liquefaction increases with the calculated thickness of the seabed. When the calculated thickness of saturated sand seabed is small, the liquefaction depth is the smallest, but the corresponding shear failure depth is the largest under the same conditions. The wave length is about 0.2 ~ 0.3), and the seabed is the most vulnerable to damage, and the depth of destruction is larger. The shear failure of sandy soil seabed may occur at the peak and trough under the wave action, while the transient liquefaction occurs only at the trough position. The liquefaction depth is within the range of shear failure depth.
【作者单位】：中国海洋大学环境科学与工程学院;山东省海洋环境地质工程重点实验室;
【基金】：国家自然科学基金项目“黄河口侵蚀再悬浮物海床内部输供及控制因素研究”(41272316)资助~~
【分类号】：P731.2;P751

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