The study of near and far field earthquake effects on non homogeneous earth dam dynamic response (Case study Karkheh Dam)

Various studies focusing on earthquake s influences on earthen dams have been undertaken, however, the behavioral complexity of these hydraulic structures under various geometric and physical circumstances and different earthquake features nonetheless, have not received elaborate and detailed deliberations to arrive at more accurate results. The purpose of this paper is to critically investigate the influence of height, body slope and near and far fault ground motion features on dynamic response of non-homogeneous earthen dam. The methodology involves assessing effect of reservoir s water level on near and far faults ground motions using finite element software ANSYS 14.0 on Karkheh Dam. The results show that dams with designs that feature low and high heights tend to be more critical against far and near earthquakes respectively. They further show that various body slopes and reservoir s water level do not produce significant effects on dynamic response of earth dams under conditions of far and near earthquakes. It was also found that decrease in Vmax/Amax parameters has a corresponding decrease in dam crest displacements, while for the PGV parameters a completley different behavior is observed. The study shows that the Karkheh dam has a critical response against near earthquakes than those for the far earthquakes and with a considerable strengthening quality that can protects it against potentials earthquakes measuring up to 6.9 Richter scale magnitude and 0.2g PGA.

کلیدواژه ها:

Earth dams ، Near and far earthquakes ، Dynamic analysis ، Karkheh dam