Mechanism and discharge prediction of the debris flow that is induced by a landslide

滑坡泥石流发生机理及流量预测

基本信息

批准号：
10480094
负责人：
TAKAHASHI Tamotsu
金额：
$ 6.53万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-10480094/
关键词：
landslide slip liquefaction debris flow scale prediction experiment numerical simulation

项目摘要

Recently in Japan, large scale debris flow that is induced by landslide often occurs. But, the discharge and the hazardous area of that kind of debris flow cannot be predicted, because, at the moment, there is no predictive model. This investigation aims to present a predictive model of viscous debris flow generated by a landslide.Whether the debris flow is induced in contractive soils or in dilative soils may require different way of water supply that is necessary to fill up the void space among particles in debris flow. Here, the landslide is assumed to occur in dilative soil block by the appearance of saturated soil layer near the slip surface.A test piece of dilative soil that contains plenty of water was prepared in a steep experimental flume, and it was released to move down slope. The lower saturated layer was liquefied by shearing, and it was left behind the soil block as debris flow. The soil block becomes thinner and thinner with its advance down the slope, and the total volume of debris flow left behind increases.The speed of liquefaction was given as a function of water content and shearing rate, and a system of equations that describes the motion of the soil block was obtained. The validity of the theory was proved by comparing the theoretical results with experiments. Another system of equations that is able to predict not only the motion of soil block but the motion of debris flow even after stoppage of the soil block is obtained. The Harihara River debris flow that is a typical landslide induced debris flow will be reproduced numerically using the newly developed theory.

最近，在日本，经常发生由滑坡引起的大规模碎片流。但是，无法预测这种碎屑流的排放和危险区域，因为目前尚无预测模型。这项研究旨在提出一个由山体滑坡产生的粘性碎屑流的预测模型。无论是在承包土壤还是在扩张土壤中诱导碎屑流，可能需要不同的水供应方式，这是填充碎屑流中颗粒之间空间的所必需的。在这里，假定滑坡在稀疏的土壤块中通过饱和土壤层的出现在滑动表面附近。一块含有大量水的扩散土壤在陡峭的实验水槽中制备了大量水，并释放出来以向下移动。下部饱和层是通过剪切液化的，随着碎屑的流动，将其留在土壤块后面。土壤块变得越来越薄，并且其前进的斜率下降，并且剩下的碎屑流的总体积增加。液化速度是作为水含量和剪切速率的函数以及描述土壤块运动的方程式的函数。通过将理论结果与实验进行比较，证明了该理论的有效性。另一个方程式系统不仅能够预测土壤块的运动，而且还能获得碎屑流动的运动，即使在土壤块中停止之后。是典型的滑坡碎屑流的Harihara河碎片流将使用新发展的理论进行数值重现。