Torsional and flexural resonant column testing of grouted sands

Torsional and flexural resonant column tests were conducted on sands grouted with a fine cement and the effects of confining pressure, strain, grout water-to-cement ratio (W/C) and sand grain size and shape were evaluated. Both types of excitation were applied on a single grouted sand specimen without causing specimen failure. Flexural excitation of grouted sands has not been reported in the literature to date. The grout W/C ratio had the strongest effect on the dynamic properties of the grouted sands and on the improvement of clean sand properties due to grouting. Depending on grout W/C ratio and confining pressure, the shear and Young's moduli, the torsional and flexural damping ratios and the Poisson ratio of the clean sands were improved by a factor of 6-36, 1.1-7.3 and 1.02-1.82, respectively.