Post - liquefaction ground flow in shaking table tests

ABSTRACT

The behavior of liquefied ground in lateral flow was studied in shaking table using a smaller and a larger container. Tests were conducted in a submerged model slope made with Toyoura sand. The dilatancy characteristics were considered to be very important. Since the shear deformation behavior of model ground at low confining pressure is dilative, the flow created in regular1-G shaking table tests is limited and cannot continue after shaking stops. However, this problem was solved by using a very loose model ground with contractive behavior. The model ground was prepared by moist placement and wet tamping methods. In order to trigger free flow an impact load was applied in the direction perpendicular to the slope (Transverse direction). Some tests were conducted with continuous shaking applied in the direction parallel to the slope (Longitudinal direction). In order to observe the soil deformation in detail, markers made from dyed sand were placed in contact with the transparent side wall of container. The displacement obtained from markers and a transducer placed in the center of the ground were compared. A relationship between the velocity of flow and the void ratio was obtained. Results of experiments with free flow triggered by an impact load and flow applied by continuous shaking were also examined.(AU)