Dynamic Behaviors of a Hollowed, Cylindrical Soil Specimen under Cyclic Torsional Shear Loading (Part 1)

Effect of Cyclic Excitation, Frequency and Bulk Density

Abstract

Indoor experiments using cyclic torsional shear loading test method were conducted to clarify the dynamic behaviors of soil compaction induced by repetitive passages of a tractor in the field, particularly focusing on the turning operation. It was ascertained that an increase in the number of cyclic loading caused continuing increment of both torsional shear strain and pore water pressure until the soil specimen failed, since the developing pore water pressure weakened the soil specimen. The magnitude of torsional shear strain corresponding to cyclic torsional shear stress was affected by loading frequency and bulk density. However, the effect of loading frequency and bulk density was found to be not clear after investigating the relationship between the torsional shear strain and the effective stress ratio.