Abstract
Liquefaction happened in a wide area along Pacific Ocean coastal area during the Eastern Japan Great Earthquake. The influence of repeated long-time earthquake followed by a quiet consolidation period has been investigated carefully in this study. The calculation is conducted with soil-water coupling finite element-finite difference analyses based on the cyclic mobility model. From the analysis, it is known that some small sequential earthquakes, which might not affect the liquefaction of the ground anyhow in an independent vibration, cannot be neglected for their impact to the liquefaction if they vibrate the ground after a major vibration. In order to predict correctly the ground behavior in such repeated earthquake vibration that may occur in future, it is necessary to deal with this geotechnical engineering problem based on sophisticated numerical analysis proposed in this paper. From the work in this paper, it is possible to understand the dynamic behaviors of soil such as, increasing and dissipation of excessive pore water pressure during or after earthquake, the development of stress-induced anisotropy, liquefaction and consolidation etc.
