Experimental evaluation of salinity geosynthetics capillary barriers

Abstract

This paper explores the transient upward flow of saline water in one-dimensional soil and soil-geosynthetics columns to evaluate preventive measures to mitigate salinity rise. Unsaturated soil concepts are utilised to elucidate the salinity movement through geotextile and geocomposite drain interfaces. The presence of a geotextile layer slowed down the capillary rise of the saline water. However, it did not prevent the breakthrough of the saline water due to the hydrophilicity of the geotextile and the suction at the geotextile base being close to the geotextile's water entry suction value.  In contrast, using a geocomposite drain mitigated the upward saline wetting front. It acted as a salinity capillary barrier due to the initial hydrophobicity of its geotextile component and the air gap present in the geonet core.