Influence of Loading and Loading-free Processes of Cyclic Torsional Shear to Soil Compaction

Abstract

The loading and loading-free processes of a cyclic torsional shear test were conducted to investigate and simulate the soil behavior induced by machinery services in the field during crop production. The results showed that the corresponding torsional shear deformation was found under the cyclic loading process accompanied by the development of pore water pressure. On the other hand, an increase of bulk density and axial strain occurred on the loading-free process and seemed to be affected by the development of pore water pressure in the preceding cyclic loading process. A comparison with the normal cyclic torsional shear loading test was also made in order to distinguish the specific soil behavior under both loading modes. Moreover, the effects of loading magnitude, amount of the number of cyclic loading in the loading set and bulk density were clarified. Also, the stress path tracing in the state space was investigated to help explain the soil behavior under loading and loading-free processes.