Comparison of effects of complex initial stress state parameters on undisturbed loess dynamic properties

The foundation soil masses under buildings and structures are always in complex initial stress states. Although numerous studies have been conducted on the influences of the complex initial stress state parameters on loess dynamic properties, the influences of those parameters are rarely compared. This study focuses on the comparison of the influences of those parameters (i.e. the angle of initial principal stress alpha(0), the coefficient of initial intermediate principal stress b(0), the initial deviatoric stress ratio eta(0) and the initial average principal stress p(m0)) on loess dynamic properties in China through laboratory testing. The results show that the effects of p(m0) on the maximum dynamic shear modulus G(0) and the maximum dynamic shear stress tau(dmax) are similar to the effects of the confining stresses. G(0) and tau(dmax) decrease with the increment of alpha(0). G(0) increases while tdmax decreases with the increment of eta(0). Among the three parameters (alpha(0), b(0) and eta(0)), alpha(0) causes the largest differences of G(0), whilst eta(0) causes the largest differences of tau(dmax). Therefore, alpha(0) and eta(0) should be given priority to the dynamic response analysis and anti-seismic design of the projects in loess areas.