Effect of granular bed on behaviour of stone column improved ground

Abstract

-Stone columns are known as an economically and efficient method to improve a wide range of soils. For drainage purposes, as well as distribution of the applied stress coming from superstructure, usually a granular bed, performs on top of the stone columns improved ground. In this paper effects of the granular bed on the stone column were studied numerically. Mohr-Coulomb failure criterion was considered for all the materials. Accuracy of the model verified by other laboratory test data and was found to be in good agreement. The results showed that construction of a granular bed causes more stress to transfer to depth of the column and thus stress concentration reduced in the upper part of the column and lateral bulging reduced subsequently. Also, influence of the granular bed on the settlement and bearing capacity was evaluated and it was found that placing a granular bed on the stone column improved ground significantly increase bearing capacity and decrease settlement of the ground.