Correlation Between Single Component Durations and Damage Measures of Concrete Gravity Dams

Strong motion duration is one of the challenging characteristics of ground motion, which affects the cumulative damage of structures significantly. Many researchers have conducted investigations related to the effects of strong motion duration on the response of building structures. However, the corresponding studies of concrete gravity dams are limited. This study describes numerically, the interdependency between several different definitions of strong motion duration and structural accumulated damage indices, and the aim is to determine the definitions of strong motion duration that exhibit the strongest influence on structural damages. For this purpose, 20 as-recorded accelerograms with a wide range of durations, which are modified to match a 5% damped target spectrum, are considered in this study, and several different definitions of strong motion duration, such as significant duration, bracketed duration and uniform duration are proposed for measuring these durations. On the other hand, nonlinear seismic analyses of concrete gravity dams subjected to earthquake motions with different strong motion durations are conducted. Peak displacement, local damage index, global damage index and damage energy dissipation are established for characterizing the influence of strong motion duration on the dynamic response of concrete gravity dams. The degree of the interrelationship between single component durations and damage measures is provided by correlation coefficients.