Experimental analysis on dynamic characteristics of unsaturated sericite schist residual soil controlled by different factors

Taking sericite schist residual soil widely distributed along Dalin Railway as the research object, the resonance column test of sericite schist residual soil in unsaturated state was carried out, and the dynamic shear modulus G_d under different water content, dry density and consolidation confining pressure in small strain range (10⁻⁶ < γ_d < 10⁻⁴) was studied. The test results show that water content has a great influence on dynamic shear modulus, followed by dry density and consolidation confining pressure. G_d increases non-linearly with the increase of water cut, and there is a certain critical water cut that makes G_d reach the maximum, and then G_d gradually declines with the increase of water cut; D ∼ γ_d curves tend to overlap under high confining pressure and high water content. Under the same dynamic shear strain amplitude, G_d increases with the increase of dry density. Under different consolidation confining pressures, the increasing of G_d follow-up shear strain γd tends to decrease.