Water content, effective stress, and rotation speed impact on the abrasivity of granular soils in LCPC test results

The development of mechanized tunneling technology and the extent of its application in the soft grounds have revealed the importance of soil abrasivity studies more. As one of the first methods of soil abrasivity assessment, LCPC test is widely used in predicting the wear of cutting tools in soft grounds. In this study, the effect of water content, rotation speed, and applied stress on the abrasivity of crushed silica particles are investigated with the LCPC tests. The results showed that water content has a considerable effect on the abrasive behavior of silica particles. The occurrence of drainage during the tests considerably changed the dominant conditions of moisture and affected the observed wear rates. The obtained correlation between the effective stress levels and recorded wears showed that the theory of granular soils compaction can be used to describe the variations of soil abrasivity with water content changes. Moreover, the results showed a direct linear correlation between the rotation speed of steel propellers and measured wears. The same correlation was also found between effective stress levels and wear amounts. However, in the samples with higher water content than 10 percent, the effect of stress on the wear rates increases with the increase of propeller rotation speed.