摘要
山区流域植被发育斜坡的失稳往往尾随着强降雨而发生,降雨入渗引起的地下水位上升是导致斜坡失稳的主要原因,而饱和渗透系数是评价土体渗透特性的主要参数。以植被发育斜坡土体为研究对象,应用CT扫描技术获得了土体孔隙尺寸分布,发现孔隙成圆率随着等效直径的增大有减小的趋势,即孔隙截面积越大,其形状越复杂。根据毛细管束模型预测出饱和渗透系数,再与环刀法测得的饱和渗透系数对比,发现预测值和实测值在相同数量级范围内,但还是存在一定的偏差。进一步对模型优化,修正孔隙形状系数后,模型的预测精度得到了显著提高。
Heavy rainfall in mountainous watershed is always followed by development of vegetated slopes instabili- ty, for its main reason is the ascension of the groundwater level caused by rainfall infiltration. Saturated permeabili- ty coefficient is a main parameter in evaluating the infiltration characteristics of soils. Taking well vegetated slope soils as research object, we obtain the pore size distribution characteristics by using CT scanning technology, and find that round rate of the pore decreases with the increase of equivalent diameter, namely, the larger of the pore section area, the more complex of its shapes. The saturated permeability coefficient is predicted using the Bundle of capillary tubes model firstly, then compared with the value which determined by the cutting- ring method, the re- sults shows that, the forecast values and measure values are in the same order of magnitude, but there are still some deviations between them. After optimizing the model and revising the pore shape factor, the prediction precision of this model has been improved dramatically.
出处
《自然灾害学报》
CSCD
北大核心
2015年第5期112-118,共7页
Journal of Natural Disasters
基金
国家自然科学基金-云南联合基金重点项目(U1033601)
高等学校博士学科点专项科研基金项目(20135314110005)~~
关键词
植被发育斜坡
滑坡
CT扫描
大孔隙
渗透系数
毛细管束模型
well vegetated slope
landslide
CT scanning
macro pore
permeability coefficient
Bundle of capil- lary tubes model
