Abstract
It is imperative to examine the properties of soils eroded due to acid rain in order to increase our understanding of the influence of acid rain on geotechnical engineering. Two test methods were employed, the infiltration method and the soak method, to investigate the physico-chemical and engineering behavior of soils eroded due to acid rain. Significant effects of artificial acid rain on the physico-chemical properties were observed compared to engineering properties. The variations of the physico-chemical properties of eroded soils such as an increase in the pH value of outflow and soaked water, an increase in the cation concentration of the outflow and soaked water, a decrease in the pH value of a specimen, and a decrease in the exchangeable cation concentration of the specimen were examined. These variations were caused by an ion-exchange reaction between the exchangeable cations in soil specimens and the H+ ions in acid rain. The concentration of water-soluble cation and the electric conductivity increased by continuing to infiltrate or soak, showed a larger increase in Kanto Loam than that in alluvial clay and decomposed granite soil. These physico-chemical behaviors were strongly affected by the pH level of artificial acid rain, and a more significant change was observed under a higher acid condition than under a weaker one. For engineering behavior, an increase in the sensitivity ratio and in the liquid limit was detected when alluvial clay was soaked in the higher acid rain.
