Jeoloji Münendisliği Dergisi

Ion Migration Mechanism in Lime Column Applications in Swelling Soils

ABSTRACT: Stabilisation of swelling soils by using lime column technique has been investigated for many years a n d there have been numerous studies on this topic in the literature. The common view in these studies is that stabilisation mechanism of lime column technique is based on physico-chemical reactions occurred as a result of migration of Ca2+ a n d OH- ions from lime column to the surrounding soil. In spite of this, ion migration which is the basis of stabilisation, a n d the factors affecting ion migration have been mentioned in very few studies. This study is a review type study a n d the purpose of the study is to provide a better understanding of the mechanism of ion migration in lime column applications. In the scope of the study, firstly, movement of ions in soil medium in general is explained. Afterwards, ion migration mechanism that occurs during the stabilisation of swelling soils with lime column technique, a n d finally the factors affecting ion migration mechanism are explained by referring to the studies on this topic. In the result of the study, it was seen that in the literature there is no a single a n d precise mechanism that explain ion migration. However, it can be said that the migration of ions in to the soil is a function of ion diffusion a n d mass transport depending on water flow.