Experimental study on the behaviour of sand compaction columns in sandy strata

In the present study, laboratory plate load tests were carried out on sand compaction columns (SCC) installed in dry sandbed to assess the behavior of the SCC improved strata under static loading. The drop hammer compaction method was used to install the columns in the sandbed prepared for a particular density in the test tank. Column depth and diameter employed were 500 mm and 60 mm respectively throughout the study. A series of tests were conducted on single SCCs, and column groups to investigate the pressure-settlement behavior of the SCC improved sandbed.  Tests were carried out on the columns with the spacing to diameter ratio (S/D) of 1.5 to 3.5 installed at sandbed prepared at an initial relative density (RD) of 30 to 60%. It is found from the study that for the loose sand strata of 30% RD, the maximum improvement achieved by adopting 1.5D spacing doubles the RD to 57%.