PROPOSAL OF EMPIRICAL EQUATION ON PHASE TRANSFORM ANGLE OF SANDY SOILS

A phase transform angle is known to be an important parameter in the liquefaction analysis, but there is little research on the phase transform angle, it is assumed to be constant or to be proportional to the internal friction angle in practical. In this study, we read off phase transform angles and the internal friction angles from the cyclic shear test results on sand under the triaxial condition. It is found that the phase transform angles scatter between 18 and 28 degrees, and there is strong correlation with the internal friction angle when the fines content is less than 20 %. Based on the findings, an empirical equation is proposed in which the phase transform angle is expressed as a function with respect to the internal friction angle.