Ultrasonic Removal of Clogging and Evaluation of Flow Capacity of Geotextile Drain

Abstract

Clogging of geotextile drains is very common when used in fine-grained soil geo-structure such as reinforced earth retaining wall, slopes, embankments. As on date the index properties of the embedded drains are usually standardized with respect to factory-defined parameters. This paper explains the application of ultrasonic excitation for the removal of clogging of geotextiles drains extracted from two fine-grained soils, Kanto Loam, a naturally occurring soil in Japan and a commercially available clayey silt, whose drainage capacity was tested with consolidation from slurry stage. The mechanism of ultrasound for the cleaning of clogging as well as various other similar industrial applications has been explained. The amounts fine-grained soil entrapped within geotextile pores, before and after cleansing in an ultrasonic water tub was evaluated. Several terms, such as clogging index, clogging potential, cleansing efficiency, have been explained and evaluated based on the experimental data. The in-plane and cross-plane flows of clogged geotextile drains, both before and after ultrasonic cleaning, showed that cleansing efficiency was greater than 80%, which were irrespective of the type of geotextile selected and the nature of clogging by both fine-grained soils. Compared to the clogged geotextile specimens’ transmissivity and permittivity recovered nearly to 75% and above after ultrasonic cleaning. The importance of geotextile drains under confinement and in situ removal of its clogging by ultrasonics is elaborated.