Improvement in liquefaction resistance of pond ash using stone-sand columns

Abstract

Aim of this paper is to demonstrate improvement in liquefaction resistance of the pond ash (fly ash) due to its strengthening with stone-sand columns. Tests were carried out on a vibration table (shake table) to evaluate the liquefaction resistance of the pond ash without and with stone-sand columns. In the present study, the liquefaction resistance is evaluated in-terms of pore pressure ratio (<i>r_u</i>). The effects of spacing of stone-sand columns on liquefaction resistance of the pond ash have been studied. Tests results indicate that the addition of stone-sand columns increases the liquefaction resistance of the pond ash significantly. Further, increasing the number of stone-sand columns, the liquefaction resistance of the pond ash increases considerably. This also decreases significantly the time for building-up of maximum pore pressure; duration for which maximum pore pressures stays and total time for dissipation of pore water pressure which indicates decrease in drainage path. The proposed technique of improvement is simple and has very much practical significance.