Experimental study of debris transport driven by a tsunami-like wave: Application for non-uniform density groups and obstacles
Experimental study of debris transport driven by a tsunami-like wave: Application for non-uniform density groups and obstacles
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DOI：
10.1016/j.coastaleng.2021.103867
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发表时间：
2021-02
影响因子：
4.4
通讯作者：
Hyoungsu Park;Myung-Jin Koh;D. Cox;M. S. Alam;Sungwon Shin
中科院分区：
文献类型：
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作者：
Hyoungsu Park;Myung-Jin Koh;D. Cox;M. S. Alam;Sungwon Shin
水上灾害碎片可通过碎片撞击和碎片筑坝载荷以及在这些事件发生后降低基础设施系统的功能，加剧对建筑环境的损害。因此，了解灾害碎片的迁移对于灾害管理至关重要。本文对海啸泥石流在平板试验台上的传播进行了实验研究，考虑了不同的泥石流单元密度条件。两种不同材料（密度）的碎片元素被视为不同的碎片组和起始方向。最后的位错和局部速度的碎片元素进行了光学测量，并比较流速。在一个碎片组中的两个碎片单元中，发现密度较高的碎片单元影响密度较低的碎片的平均纵向位移，但密度较低的碎片不影响密度较高的碎片的位移。此外，还发现碎片组的初始方向对最终位移没有可测量的影响。考察了障碍物对碎片通过的影响以及碎片与障碍物碰撞的概率，研究了碎片与碎片、碎片与障碍物从卷吸到最终错位的相互作用过程。据发现，碎片密度较低与碎片密度较高的情况相比，与障碍物碰撞的可能性较高。然而，当碎片类型混合时，密度较小的碎片发生碰撞的可能性较低。最后，对不同密度条件下的碎屑位错特征和速度场进行了整体评价。碎片的反射波和碎片间的相互作用对碰撞概率有影响。然而，每个碎片单元的密度是决定碰撞概率的一个主要因素。
Water-borne disaster debris can exacerbate the damage on the built-environment through debris impact and debris damming loads and by decreasing the functionality of infrastructure systems after these events. Therefore, an understanding of disaster debris transport is essential for disaster management. In this paper, an experimental study of tsunami-driven debris spreading over a flat testbed was conducted considering different density conditions of debris elements. Debris elements of two different materials (densities) were considered various debris groups and starting orientation. The final dislocations and local velocity of debris elements were measured optically and compared to flow velocity. Among two debris elements in a debris group, it was found that debris elements of higher density affected the mean longitudinal displacement of the less dense debris, but the less dense debris did not affect the displacement of higher density debris. Also, it was found that the initial orientations of the debris groups had no measurable impact on the final displacement. The effects of obstacles on the passage of debris and the probability of collision to obstacles were examined and the process of debris-debris and debris-obstacle interactions from debris entrainment to final dislocation was studied. It was found that the less dense debris had a higher probability of collision with the obstacles compared to the more dense debris case. However, when the debris types were mixed, the less dense debris had a lower probability of collision. Finally, the characteristics of debris dislocation and velocity fields under various density conditions as a group were also evaluated. The reflected wave and interaction among different debris play a role in the probability of collision. However, the density of each debris element was a dominant factor in determining the collision probability.