水利水电科技进展Issue(2)：35-41,7.DOI:10.3880/j.issn.1006-7647.2016.02.007
细粒含量对泥石流斜坡失稳模式与规模的影响
Impact of fine particle content on mode and scale of slope instability of debris flow
摘要
Abstract
In order to study the impact of fine particles ( d≤0. 075 mm) of the soil body of debris flow on the inoculation and startup mechanisms of debris flow during the rainfall infiltration and interstitial flow processes, an experiment on slope debris flow induced by artificial rainfall, using a self-made debris flow model tank and an indoor slope model made of three kinds of fine particle soil bodies, was carried out. The experiment studied the formation characteristics of slope runoff, soil erosion characteristics, and slope instability modes of the soil body of debris flow during the rainfall infiltration process. The experimental results show that fine particles of the slope will disperse, drain, and cause coarsening of the surface soil of the slope. The dispersed fine particles of a slope with high fine particle content will migrate to depth, block the holes, and decrease the permeability ( infiltration capacity) of the slope soil, inducing slope runoff and slope failure before the wetting front extends to the lower soil-rock interface, with the failure surface being close to the wetting front ( only a few centimeters away) . The failure mode can be described as sliding-flowing failure of the block at first, and then gully erosion. The scale of soil erosion is related to the rainfall intensity and fine particle content. The failure mode of slope soil with low fine particle content can be described as retrogressive slumping. However, in the experimental process, no massive soil loss occurs, the blockage in the holes of soil with low fine particle content caused by the dispersion and migration of fine particles is not significant, and relatively stable flow with fine particles forms at the soil-rock inter-surface. The fine particle content of the slope soil is important to the slope failure mode and formation of the slope runoff. The security coefficient obtained from the slope stability analysis model considering the impact of the slope runoff shows better agreement with reality.关键词
泥石流/颗粒运移/细粒含量/失稳模式/稳定性分析/模型试验Key words
debris flow/particle migration/fine particle content/failure mode/stability analysis/model experiment分类
天文与地球科学引用本文复制引用
王志兵,李凯,汪稔,胡明鉴..细粒含量对泥石流斜坡失稳模式与规模的影响[J].水利水电科技进展,2016,(2):35-41,7.基金项目
国家自然科学基金(41302227) （41302227）
广西自然科学基金(2012GXNSFBA053138) （2012GXNSFBA053138）
广西高等学校科研项目(201204LX179) （201204LX179）
