Behavior of seepage pore-water pressure and its influence on slope stability in embankment by rainfall

降雨渗流孔隙水压力行为及其对路堤边坡稳定性的影响

基本信息

批准号：
13650552
负责人：
NARITA Kunitomo
金额：
$ 0.9万
依托单位：
Aichi Institute of Technology (A.I.T.)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650552/
关键词：
Centrifuge Model Test Seepage by Rainfall Pore Water Pressure Saturated Zone Slope Failure Saturated-Unsaturated Seepage Seepage Properties of Unsaturated Soil 遠心模型型実験

项目摘要

The behavior of seepage flow developed in an embankment due to rainfall and its associated features of extension of the saturated wet zone and those of pore-water pressure development, which promotes instability of slopes., were studied in this research project. Centrifuge seepage tests were conducted on several model fills, in which small size measuring devices of pore-water pressure were installed in matrix, by use of a device which can supply a uniform and constant strength of rainfall over the slope surface. Finite element unsteady saturated-unsaturated seepage analyses were made on the prototype of the model fill for the same rainfall conditions as adopted in the tests. Concluding remarks drawn from the present study are summarized in the following.(1)Seepage behavior due to rainfall is strongly affected by the intensity of rain r, and the permeability k, inclination of slope and the initial moisture of the fill ; Extension of the saturated wet zone is controlled by the difference … More of seepage water flowing in and out from the fill.(2)During rainfall, the front face of the wet zone gradually falls down from the slope surface, making the saturated wet zone at the toe, and it enlarges from the toe to the interior of embankment as the time elapses.(3)A sign of slope failure and the reduction of safety factor were confirmed in the test at the total amount of about 150mm and the intensity of 30mm/h of rainfall, which is often experienced in the past case histories of slope failure.(4)Extension of the saturated wet zone and reduction of safety in the fill are largely dependent on the initial moisture ; in the fill having high initial moisture, like a fill which has experienced a long-term rainfall beforehand, enlargement of the saturated wet zone and corresponding reduction of safety are remarkably fast and intensive in an early stage of rainfall.(5)The influence of rainfall seepage on slope stability is rather small for fills with a moderate slope, even if extension of the saturated wet zone is remarkable, because they have essentially higher safety in slope stability.(6)As for centrifuge testing method on moisture and permeability of unsaturated soils, the procedure using centrifuge test together with 1G test is verified to be much advantageous because centrifuge acceleration applied in the test made the drainage process faster and realized a considerably large reduction of the test period, and because successive measurement was satisfactorily done in a fairly wide range from saturated state to a state of low moisture content. Less

由于降雨而在路堤中的seepop的行为，是矿水压力发展的饱和湿区的特征，这促进了斜坡的不稳定性。在矩阵中安装了一个统一的雨水降雨的故事。填充物的水分；在降雨中流入和流出的渗流。在过去的坡度失败的情况下，总数约为150毫米，而在越来越多的情况下，经常经历的30mm/h的强度。在降雨的早期阶段，饱和的湿区和降低的安全性是显着的。在测试中提高离心机的高度离心机使排水过程更快，并意识到测试期的离子很大，并且由于连续的测量在相当宽的范围内从饱和状态进行了相当大的测量，从饱和状态进行低低低点。