DYNAMIC CENTRIFUGE TESTS ON FLOW SLIDES OF FILLS AND INFINITE SLOPES

Osamu Matsuo, Yukiko Saito, Tetsuya Sasaki, Koichi Kondoh and Takashi Sato

ABSTRACT: Earthquake induced flow slides of saturated or partially saturated sloping ground have taken place in man-made earth structures during past earthquakes. Two series of dynamic centrifuge model tests�@(1:50 scale) were conducted to simulate the behavior of embankment fills and infinite slopes resting on a stiff sloping base. Conditions that yield earthquake-induced flow slide were investigated. The test parameters included soil density, slope angle, level of phreatic water and shaking intensity. The test results showed that downward deformation increased with decreasing soil density, increasing phreatic water elevation and shaking intensity, and that there existed a threshold soil density below which flow slides occurred. Undrained monotonic loading torsional simple shear tests were also conducted. Conditions inducing very large deformation or flow slide that were obtained by the undrained shear tests were consistent with those as observed in the model tests.

Key words: centrifuge model test, earthquake, flow slide, residual strength, seepage, slope (IGC: D7/E8)