Seismic and geotechnical aspects of the large earthfill dam in a seismicaly active region

The seismic and geotechnical aspects of 150M height Mixed-Clay core earthfill dam located in North of Iran in a severe seismic area near some main faults are discussed. As the dam is located in highly seismic area with some main faults, both ground shaking and fault movements in the dam foundation should be considered in the design. As a main fault is within a distance of about 1.5 km nom the dam site, which can produce earthquakes with a magnitude up to 7.4, movements might be also anticipated along the minor faults or discontinuities in the bedrock. At least one minor fault (Fl) cut the dam site. The design against multiple fault movements is considered so that after faulting and slip movements, adequate width of filter and transition zones are still available. The results of dynamic analysis are also presented to show the stability of the designed dam during earthquake loading. Sufficiency of designed filter and transition and considered Beeboard is also concluded considering the results of dynamic analysis.

Keywords:

seismic design , fault movement , dynamic analysis , permanent deformation