Assessment of Engineering Geology and Seismic Hazards of Bardasoor Dam, Iraq

The Bardasoor dam in Kurdistan of Iraq is designed over the alternating sedimentary rocks of sandstone with calcite and iron oxide cements from the Injana (Upper Fars) Formation (Mio3 i, Upper Miocene). Walls of the dam have been formed of alternative sandstone outcrops. Tops of the walls have been covered by horizontal conglomerates (Bai Hassan Formation). These alternations of sandstone sedimentary rocks in the axis and walls of the dam are probably good rock for base of the dam. Island-braided channel patterns along the Diyalah River and the dam site show that this region is tectonically active. Tectonically, the Diyalah River has been formed along a right lateral fault with a strake slip vector. But the fault is not active, because it has a strike parallel with main stress (δ1) implemented to the area from the Saudi Arabia plate; hence, it will be passive. Fault-2 is a passive fault during upper Pliocene and Quaternary, because the fault did not cut the Bai Hassan Formation and Quaternary deposits. Seismologically, the location of the dam is suitable to build the dam because of passive faults near the dam site, which have no movements during the Quaternary. But the area is near the active faults of the Zagros fold-thrust Belt in the Iran and fault-3. The calculations of seismicity in the dam site show that the study area is placed in the range of low (acceleration gravity is between 15-20%) seismic. Maximum values of MCE, DBE, and OBE at the dam site are considered MCE=0.193g, DBE= 0.166g OBE= 0.105g.

Keywords:

Engineering geology , seismic hazards , Diyalah River , Bardasoor dam , Iraq