Deformation-failure mechanism of saturated fill slopes due to resonance phenomena based on 1g shaking-table tests

摘要

Earthquake motions include waves of various frequency bands ranging from low to high frequency. Notably, the dominant frequency affects the seismic stability of fill slopes. Hence, to analyze the deformation-failure mechanism during an earthquake, 1g shaking-table tests were conducted in this study on saturated fill slopes considering the resonance phenomenon. Results show that the deformation-failure mechanism of a fill slope cannot be defined by only one sliding surface. Multiple sliding surfaces are formed progressively depending on the ground and external conditions. Moreover, evaluating the seismic stability of fill slopes depends not only on the magnitude of the acceleration, but also on the relationship between the natural frequency of the fill slope and the input frequency. These phenomena cannot be considered in the seismic-intensity method nor in the Newmark's method used in conventional design. When implementing seismic countermeasures, it is important to determine the frequency characteristics of fill slopes and design the countermeasures considering the predominant frequency of the seismic wave anticipated at the site.