G MS THESIS_final version_Maxim Prokudin.pdf - Digital Repository ...

52Nuclear gauge is portable, simple to use and very useful for quality control applications.However, the device possesses some limitation, where depth of penetration is only extendedup to 150 mm and presence of organic matter and coarse particles may induce a discrepancyto the collected results (Randrup and Lichter, 2001). The loess material was deemed to beclean of any organic or coarse material and, therefore, the moisture content deviation of lessthan one percent was expected from the true water content value.The test was carried out according with ASTM D7013-04 and the device was calibrated inthe test bed prior to operation. Nuclear gauge device was used to obtain moisture content anddensity results for test bed prepared for single piers of various composition and can be foundin Table 11. The test results have shown no particular influence of the concrete walls on themoisture content and density results.Shelby Tube SampleBeing unable to utilize nuclear gauge device at depth greater than 150 mm, an additionalmethod was utilized where a soil sample of 72 mm in diameter and 140 mm in height wasextracted from each pier placement location via a Shelby tube and trimmed to the size (SeeFigure 24). The Shelby tube served the purpose of creating a cavity for installation of a 1/10 thscale pier and at the same time was used to obtain a soil sample subjected towards unitweight and moisture content evaluation.While the concept of using the Shelby tube for the purpose of extracting a soil sample andperforming volumetric and moisture content analysis is not new (Handy and Spangler, 2007),the application of the Shelby tube in a scaled pier research is a new idea introduced by thisresearch study. Having the length of the Shelby tube to be 762 mm has made this methodsuitable for the long 610 mm and short 305 mm pier cavity applications. While having boththe diameter of the scaled pier and diameter of the Shelby tube to coincide at 72 mm, the useof the Shelby tube was found to be even more feasible in this research.