Experimental study on the river blockage and landslide dam formation induced by rock slides
Experimental study on the river blockage and landslide dam formation induced by rock slides
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DOI：
10.1016/j.enggeo.2019.105269
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发表时间：
2019-11
影响因子：
7.4
通讯作者：
Hai-mei Liao;Xing-guo Yang;Gong-Da Lu;Jian Tao;Jia‐wen Zhou
中科院分区：
文献类型：
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作者：
Hai-mei Liao;Xing-guo Yang;Gong-Da Lu;Jian Tao;Jia‐wen Zhou
强震或强降雨引发的岩石滑坡可能会造成不同程度的河道堵塞，对山区河流的连续性造成重大影响。根据堵塞的程度，本文将堵塞类型分为三类：无堵塞(淹没坝)、部分堵塞和完全堵塞。滑坡过程中滑动物质的堆积过程是理解滑坡坝形成的重要问题。本文通过建立滑坡和河谷模型来研究滑坡的典型运动过程和侵位规律，并对滑坡坝的形成因素进行了深入的分析。试验研究表明，尽管岩石破碎程度和流动条件不同，但堆积高度与滑坡体积呈正相关。碎屑程度越低，最大沉积高度越大，最小沉积高度越小，碎屑程度越好，最大沉积高度越小，最小沉积高度越小。此外，水深对河道堵塞类型有显著影响。提出了一种新的结合滑坡体积和湿截面积的堵塞指数(BI)来评价滑坡的筑坝能力。在此基础上，提出了一种基于堵塞指数与最大水深或最小水深之比与水深的关系来预测滑坡堵塞类型的方法。本文提出的模型可用于今后类似岩层滑坡坝体形成的辅助预测。
Rock slides triggered by strong earthquake or heavy rainfall may cause different degrees of blockage in flow channels, resulting in a significant impact on the continuity of mountainous rivers. Based on the extent of blocking, the blockage type is divided into three categories in this paper: no blockage (submerged dam), partial blockage, and complete blockage. The accumulation process of sliding materials in the course of rock slides is an important issue for understanding the formation of landslide dams. In this study, rock slide and river valley models are developed to investigate the typical kinematic process and emplacement of rock slides, and the factors that dictate the formation of landslide dams are critically analyzed. The experimental study suggests that there is a positive correlation between the deposit height and the rock slide volume despite differences of rock fragmentation and flow condition. In addition, the less fragmented rocks result in larger maximum deposit height (maxi-DH) and smaller minimum deposit height (mini-DH), while the better fragmented rocks result in smaller maxi-DH and larger mini-DH. Furthermore, the water depth has a significant impact on the river blockage type. A new Blockage Index (BI) that combines the landslide volume and the wet cross-sectional area is proposed to assess the damming capacity of rock slides. Then a method for predicting the river blockage type of rock slides is developed based on the relationship between Blockage Index and the ratio of maxi-DH or mini-DH and water depth. The model proposed in this work can be used to assist estimating the formation of landslide dam for similar rock slides in the future.