抄録
Size effect and time dependency are observed in most rock or bedrock. A lot of researches have been performed on both of them up to now. However, many points have been left unsettled although they are considered to be important especially for long-term stability of a large structure.
In this study, long-term slope stability around the Three Gorges reservoir was discussed considering both size effect and time dependency. There are still not so many researches in the size effect related to slope stability, and it is difficult to presume the relationships between the size effect and slope stability theoretically or experimentally. So, in this study the size effect was estimated by data analysis of apparent friction and nominal dimension of landslides occurred in the past.
Time dependency concerning slope collapse or landslide is well known. If the time dependency is remarkable, just a relatively low stress can lead to gradual deformation and then final failure. For evaluating the stability of, for example, 100 years, it is necessary to understand time dependency of the rock. For this reason, the rock collected in situ was tested in laboratory to obtain the time dependency by the recently developed testing method with relatively small specimens.
Overdesign factor required for long-term slope stability was calculated based on the size effect and the time dependency. The long-term slope stability around the Three Gorges reservoir was discussed based on the estimated overdesign factor.
