Soil Solumn Seepage Test on Clay Particles Migration Process of Granite Weathered Soil in Fujian and Guangdong Areas,China
Granite weathered soil is characterized by large pore structure and poor grading.Rainfall infiltration drives migration of clay particles,accompanying by expansion of internal pores and particle coarsening in granite weathered soil,which was recognized as the main explanation for soil-water loss and slope deformation or failure in granite area of Fujian-Guangdong region,China.In this study,a soil column seepage model experiment was designed to investigate the process and characteristics of clay particle migration in granite weathered soil under different soil grading conditions,in which the variations of soil composition,seepage discharge,and hydraulic gradient were traced for interpretation.(1)Under seepage drive,fine particles with a higher content of clay minerals in the soil,especially clay particles with a particle size smaller than 5 μm and good hydrophilicity,were prone to migration,aggregation,clogging,or re-organization processes,leading to continuous changes in seepage discharge and hydraulic gradient,then grain coarsening emerging.(2)With the increase of gravel content in the soil,internal soil particle unit developed into more distinct"mixed-grain"porous skeleton.In case of gravel content increasing from 40％up to 60％,clay particles were leached away up to a 14％of mass of loss,with seepage discharge increases by 51％.More seepage channels developed,more grain coarsening intensified,and progressively soil structure came to collapsing.(3)Clay particle migration in granite weathered soil was caused by the transition from a stable seepage state to a dominant seepage state.Once dominant flow channels were formed,the hydraulic gradient could increase by 40％.This study provides scientific basis for erosion control and slope prevention in granite area of Fujian-Guangdong region,China.
granite weathered soilparticle gradationclay particles migrationparticle coarseningFujian-Guangdong region
万方数据
维普
