Abstract
Smectite to illite transformation is assumed to be one of the factors that causes earthquakes. Interpretation of the mechanical behavior considering smectite to illite transformation is needed in the study of earthquake. It has been reported that asperity which is a slight projection from surface of the plates existed in decollement zone, and the area existing asperity is known as an earthquake occurrence area. However, the mechanism of decollement formation and mechanical behavior has not been studied rigorously.
Therefore, the purpose of this study is to challenge to this unsolved problem from the point of view of geotechnology. As the first step, the influence of dehydrating action due to smectite to illite transformation and mechanical characteristic change is modeled. Consequently, it is found that smectite to illite transformation causes increasing in share strength and hence, it is thought that this mechanism would be a major factor to cause gigantic earthquake because the energy release of deformation is estimated to be a quite large volume.
