PILOT IN-SITU AUGER MIXING TREATMENT OF A CONTAMINATED SITE - PART 2 - SITE TRIAL

This paper, Part 2 of a publication, presents details of the auger dev elopment, site trial and assessment of the in situ treatment of a pilo t in situ auger mixing treatment of a contaminated site. A prototype a uger, 0.6 m in diameter and 2.4 m long, consisting of cutting flights and mixing rods, was designed and manufactured to produce homogeneous mixing of the soil and grout with minimal exposure of contaminated mat erial. In the site trial, the seven soil-grout mix formulations propos ed at the end of the treatability study, detailed in Part 1, were appl ied. A total of 23 overlapping soil-grout columns were constructed wit h minimal problems treating around 14 m(3) of contaminated ground and resulting in a small overall volume increase of around 7%. The work pr esented in this two-part publication demonstrates the importance of th e initial laboratory treatability study in identifying suitable soil-g rout mixes and suggesting modifications to the in situ application pro cess. The pilot study demonstrated that combined treatability study an d in situ trials are an essential part of full-scale treatment methodo logy.