[H-DS08] 地すべりおよび関連現象

[HDS08-05] Gradually co-seismic failure process of gentle slope revealed by amplification effect using shaking table tests

*Ning Ma¹ (1.Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University)

キーワード：Co-seismic site resposne, Landslide induced by earthquake, Amplification effect, Time and frequecny domian, Large scale shaking table test

In recent years, earthquake induced slope failure resulted in numerous casualties and enormous economic loss.To prevent or at least mitigate possible damage from co-seismic landslides, great efforts have been made to better understand the co-seismic site response on slopes.By means of multiple approaches variously including field investigation, in-situ monitoring, model test and numerical simulation, the co-seismic site response aroused by the interaction between the seismic energy and slope was exhaustively studied.Although the monitored seismic site response has been treated as the dynamic parameter to successfully access the stable state of the slope in process, this valid approach, in fact, has been only used in revealing the slope instability induced by the driven causes of temperature and precipitation. However, it is difficult to directly study the co-seismic instable process of a slope by the in-situ monitoring since the case slope failure induced by the earthquake was hardly approached. Therefore, in this study, to better understanding the co-seismic behaviours in the slope increasingly tending to fail, we carried out a series of model tests by means of a large size shaking table.By means of the test results of the spatial and temporal distributions of the amplification effects based on the response motions within the model slopes in different shaking intensities, the detailed characteristics of change about amplification effects were firstly analyzed both in frequency and time domain, respectively. Then, the mechanism that how the geotechnical contexture of the slope may result in the variation of the amplification effects with the increment of the shaking intensity was also analyzed. Finally, the areas in the slope where the failed cracks distributed and the amplification effects changed remarkably were studied and revealed high spatial correlations and the feasibility that progressively co-seismic failed procedures could be characterized by the variable amplification effects was verified.