A Comparative Study on the Seismic Displacements of the Karkhe Large Embankment Dam with Mixed and Pure Clay Core-Iran

The water supply is the crucial problem of human beings in the world. Earth dams are usually the most important structures to store and manage the main sources: surface waters. The safety of earth dams in different conditions especially under earthquake loadings plays a vital role in sustainable developments. Recently, mixed-clay soil is widely used as water- seal material in the core of earth dams, while limited studies on their seismic behaviors have been carried out so far. This paper discusses about the displacement performance of the Karkhe Large Embankment Dam with mixed- clay core , recently constructed in south-western part of Iran ,  under earthquake motions and compares the dynamic analyses’ results with those of pure-clay core. In this study, the Karkhe Dam with both mixed and pure clay core is numerically modeled using the FLAC 4.0 software. After calibrating the model and completing the static and dynamic analyses under proper strong motions, selected based on the previous seismological studies, the results, including the maximum settlements, horizontal displacements of upstream and downstream shells under different excitations are compared and discussed. Based on the obtained results, it is noted that the dynamic performance of earth dams with mixed-clay core is more desirable than that of pure-clay core. It is also observed that the seismic settlements of the dam with pure-clay core averagely show an increase of 20 percents compared with that having the mixed-clay core.