Clogging phenomena of the residual soil-geotextile filter system

Clogging tests on residual soil-geotextile filter systems were performed, and the permeability reduction due to clogging was evaluated. An extensive experimental program was performed using two typical weathered granite residual soils that were sampled at Shinnae-dong and Poi-dong areas in Seoul. Weathered granite residual soils, which are found in much of the Korean peninsula, pose unique challenges in terms of internal stability and filtration. Two separate simulation tests with weathered residual soils were performed: the cross-plane permittivity test (filtration) and the in-plane transmissivity test (drainage). Needle-punched non-woven geotextiles are selected since they are often used as drainage material in the field. The compatibility of residual soil-geotextile filter systems was investigated with emphasis on the clogging phenomenon. It was found that filter clogging was more significant in filtration than in drainage. The permeability reduction in the coarser Shinnae-dong soil-filter system was more serious than in the finer Poi-dong soil-filter system.