Effective applications of poker vibrator for compacting quarry dust as a ground improvement technique

Abstract

Recently, quarry dust has been widely used as a ground improvement technique to replace the weak, incompetent soil under shallow foundations when there is a high groundwater table or weak soil. Practical approaches suggest that a poker vibrator can be used easily, to achieve a higher Degree of Compaction (DOC) in quarry dust, under saturated condition. However, as this technique is still novel to the industry, the expected results cannot be guaranteed. It is therefore essential to eliminate inappropriate practice by carrying out laboratory experiments on optimum poker vibration application techniques. The aim of this study was to optimize the effectiveness of poker vibrator in shallow foundation design by studying the variation of factors affecting it, including time of application, shape of the foundation, preferable layer thicknesses and application patterns of vibrators. According to the test results, the optimum period of compaction for poker vibration is around 35s/point. DOC increases with increasing application points and reduces with increasing initial layer thickness, regardless of pattern.