Predict Failure of Shirasu Slope in Consideration of Patterns of Rainfall and Unsaturated Seepage

考虑降雨和非饱和渗流模式的 Shirasu 边坡破坏预测

基本信息

批准号：
02650350
负责人：
OKABAYASHI Takumi
金额：
$ 1.22万
依托单位：
Kagoshima National College of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02650350/
关键词：
Rainfall Special Soil Shirasu Slope Stability Seepage Volumetric Water Content Pressure Head Finite Element Method 火山噴出物火山灰斜面安定不飽和浸透降雨パタ-ン土質力学

项目摘要

Shiras is a pumic-flow deposit soil widely distributed in southern Kyushu and oilier districts in Japan, and is counted to be a typical collapsible soil for its frequent damages mainly owning to rainfall and earthquakes. Such a soil seems to be similar to the yellow-brown pumice soil in North Island, New Zealand, the cemented-sand in the U. S. A., and the volcanic ash soil in Central America. The strength characteristics of the undisturbed Shirasu are different from those of the disturbed Shirasu, since undisturbed samples have tensile strengh due to a geological cause.It is well known that Shirasu becomes very collapsible after increasing the moisture content. Many studies on failure of slope by rainfall have been done by many laboratories. The failure mechanism of Shirasu has not been clarified yet, because the mechanisum of it by rainfall is very complicated.The conclusion drawn were as follows ;(1) The patern of rainfall in Southern Kyushu was become clear.(2) This study make it clear about the relation between unsaturated coefficent of permeability, water content by volume and suction of Shirasu.(3) The triaxial test results make clear characteristics of soil mechanics and liquefaction in Shirasu.(4) This paper refers to characteristics of unsaturated seepage of Shirasu slopes in raifall.

Shiras是一种在九州南部和日本油化地区广泛分布的浮石沉积土壤，被认为是典型的可折叠土壤，因为它频繁损害主要损害降雨和地震。这样的土壤似乎类似于北岛，新西兰的黄棕色浮石土，美国的水泥岩和中美洲的火山灰土壤。不受干扰的Shirasu的强度特性与受干扰的Shirasu的强度特征不同，因为未经扰动的样品由于地质原因而具有拉伸性strengh。众所周知，Shirasu在增加水分含量后变得非常可折叠。许多实验室已经完成了许多关于降雨失败的研究。 Shirasu的故障机制尚未澄清，因为降雨的机械脉络非常复杂。得出的结论如下：（1）京胡岛南部的降雨的核心很明显。（2）这项研究清楚地表明，在允许性，批量和确定的特征中，shirasu sake selection（3）的关系（3）的关系（3）。（4）本文是指莱福尔（Raifall）中shirasu斜坡不饱和的特征。