Effect of Clogging on Rate of Consolidation of Stone Column–Improved Ground by Considering Particle Migration

Abstract

Installation of stone columns is one of the most popular ground improvement techniques used to improve the strength of soft soil. Owing to the presence of more pores in the stone column, it acts as a drainage path for seepage of water from the soil during consolidation. Thus, in addition to increasing the soil’s strength, the stone column also increases the rate of consolidation of the soil. The water present in the pores of the soil is not pure, and some fine particles released from the soil are also present. During the seepage, these fines present in the fluid also move along with it. Depending upon the amount of concentration of fines present in the seepage water, the clogging of the stone column takes place which reduces the permeability of the stone column. Thus, the rate of consolidation of the ground improved by the stone column also decreases because of the clogging. In the present study, a mathematical model for the consolidation rate of soil improved with stone columns has been developed by considering the effect of clogging due to particle migration. The results are compared with the available rate of consolidation models for stone column–improved ground with or without clogging. The effects of various ranges of parameters of the developed model on the rate of consolidation are also studied. It is observed that as the diameter ratio and stress concentration ratio increase, the clogging also increases.