Seismic stability analysis of large arch dams

"Ground shaking during a strong earthquake causes dynamic tensile stresses that exceed the dynamic tensile strength of mass concrete in the central upper portion of a large arch dam. Because of the geometric constraints in an arch dam, such detached concrete blocks can normally move only towards the reservoir. Such movements would be further restrained if shear keys were provided at the contraction joints. The proposed method was applied to the case of a 250 m-high arch dam. The dynamic stability of two detached concrete blocks with heights of 20 and 40 m in the central upper portion of the darn was investigated for empty and full reservoir conditions under the ground motions produced by the maximum credible earthquake. Buildings made of brittle materials such as masonry sustain severe damage or collapse when subjected to intense ground shaking. This was confirmed, for instance, during the 2003 Barn earthquake in Iran, where many people lost their lives because of the collapse of masomy buildings with low shear strength."