Liquefaction characteristics of saturated sand deposits under partially different vertical stresses

In order to clarify the characteristics of liquefaction and liquefaction-induced settlement of liquefiable saturated sand deposits below the soil structures such as road embankments and earth dams including those with a free surface near the soil structures, a series of shaking table tests are performed on five kinds of model sand layers. The model sand layers were prepared using three Kjellman's type simple shear boxes. Most of the tests were carried out on the model sand layer (1) consists of three saturated sand layers of which the effective vertical stresses ((σ')_<vo>) are 10.4kPa, 30.0kPa and 49.6kPa. Moreover, for comparison similar tests were performed on other four model sand layers (2) to (5) consist of two sand layers which changed the ratio of small vertical stress to large one (RVS). It is found from the tests that the liquefaction characteristics of such model sand layers was affected by the RVS-values and the magnitude of vibration. Furthermore, it is shown that the distribution of liquefaction-induced settlement of the model sand layer (1) is that the amount of it remarkably increases in the range of smaller vertical stresses and takes almost a constant value as the vertical stresses increase.