权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Study on Time Dependence of Soil Pore Clogging in Slope Failure Mechanism

边坡破坏机制中土体孔隙堵塞的时间依赖性研究

基本信息

批准号：
03806037
负责人：
YASUTOMI Rokuro
金额：
$ 1.28万
依托单位：
Tokyo University of Agriculture and 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：
1991
资助国家：
日本
起止时间：
1991 至 1993
项目状态：
已结题

项目摘要

Erosion disasters occurred on agricultural lands and facilities as a result of heavy rainfall in Yasaka area. Slope failure or gully erosion of paddy field levees was most common. Soil permeability in toe of levee slope in non-consolidated paddy field was lower than that in top of levee slope. Clay percentage of samples soils in toe of levee slope was higher than that in top of levee slope. Observations of soil pores with a polarized microscope showed the sedimentation of clay particles around soil pores in toe of levee slope. It was concluded that transportation of clay particles produced soil structural changes in levee slope. As soil water pressure and degree of saturation increase easily in heterogeneous slopes, protection measures should be considered to prevent slope failure.Percolation volume of soil suspension through porous mediums per unit time decreased against the increase in the volume concentration. The changes in percolation volume per unit time were analyzed using the Backingham-Reiner equation. The conclusion was that the radius of plug flow should be a least smaller than that of pores to prevent the immediate clogging by soil suspension flow.Pipe drainage we an effective protection measure of heterogeneous slopes. It was suggested that effective strainer structure of under drain pipes in which pore radius of strainers enlarged according to flow direction was designed from rheological properties of soil suspension flow which prevented the immediate clogging. Research of strainer structure of under drain pipes which keeps constant drain-age discharge is significant for slope protection.

在Yasaka地区，由于强降雨，农业土地和设施发生了侵蚀灾害。水田堤坡折或沟蚀最为常见。非固结稻田堤坡坡脚土壤渗透性低于堤坡顶。堤坡坡脚土壤粘粒含量高于堤坡顶土壤粘粒含量。用偏光显微镜观察土孔隙，发现土孔隙周围有粘粒沉积。结果表明，粘土颗粒的运移引起了堤坡土壤结构的变化。由于非均质边坡中土水压力和饱和度容易增大，应考虑采取防护措施防止边坡失稳;土壤悬浮液单位时间通过多孔介质的渗透量随体积浓度的增大而减小。利用Backingham Reiner方程分析了单位时间内渗滤体积的变化。结果表明，为防止土体悬浮流的直接堵塞，推流半径应至少小于孔隙半径，管道排水是非均质边坡的有效防护措施。根据土壤悬浮液流的流变特性，设计了有效的排水管滤水器结构，即滤水器孔径随水流方向而增大，以防止瞬时堵塞。研究保持恒定排水量的排水管下滤水器结构对边坡防护具有重要意义。