Dispersive behavior of alluvial soil in Shah Alam, Selangor

Abstract

Dispersive soils are prone to erosion when soil particles react with water. The dispersion process occurs when a high amount of sodium ions adsorbed onto clay surfaces causes repulsion between particles, leading to deflocculation. The dispersive characteristics of alluvial soil were determined using three types of dispersion tests, namely the Crumb test, the double hydrometer test, and the pinhole dispersion test. Based on the results obtained, the alluvial soil was classified as highly dispersive by the Crumb test, while both the double hydrometer and pinhole tests indicated a moderately dispersive level. This condition is influenced by the nature of alluvial soils, which contain a high amount of clay colloids, resulting in slower water penetration throughout the soil particles. These findings are important for understanding the natural behaviour of this soil, particularly in relation to issues such as dam failure, slope stability, and building foundations.