Model tests on liquefaction characteristics of saturated sand deposits under nonuniform vertical stresses

In our previous study, in order to clarify the liquefaction characteristics of saturated sand deposit under nonuniform vertical stresses, shaking tabel tests on models were performed. It was found from the tests that RVS and k_h affects the occurrence of liquefaction of the models. In this paper, in order to investigate it in more detail, shaking table tests on three models having RVS of 0.57,0.35 and 0.21 prepared in two Kjellman's type shear boxes are performed. Here RVS=(σ'_<vo>)_1/(σ'_<vo>)_h, in which (σ'_<vo>)_1 and (σ'_<vo>)_h denote lower and higher vertical stresses of two neighboring sand elements. It is found from the tests that the liquefaction characteristics of the model are affected by the values of RVS and horizontal seismic coefficient k_h of vibration. It is also shown that an initial shear stress Δτ affects the liquefaction characteristics of the model (1) at k_h less than 0.1.