Seismic Performance Evaluation of Concrete Dams: Methods, Advances, and the Role of Strain-Rate-Dependent Tensile Strength in Demand–Capacity Analysis

The seismic performance evaluation of concrete dams is a critical task in dam safety engineering, given the catastrophic consequences that dam failure can produce. Over the past two decades, the demand–capacity ratio (DCR) and cumulative inelastic duration (CID) framework, codified in USACE EM 1110-2-6051 and proposed by Ghanaat, has become the standard methodology for linear-elastic performance assessment. However, this framework intentionally uses static tensile strength as the capacity measure, introducing conservatism by neglecting the well-documented strain-rate enhancement of concrete tensile strength under seismic loading. This paper presents a comprehensive review of the current state of knowledge on seismic performance evaluation of concrete dams, synthesizing findings from gravity, arch, and buttress dam studies. It covers the DCR/CID framework, near-fault versus far-fault ground motion effects, dam–reservoir–foundation interaction modeling, nonlinear analysis methods, and emerging capacity-based approaches such as incremental dynamic analysis (IDA) and endurance time analysis (ETA). The paper then proposes an enhanced DCR formulation that incorporates strain-rate-dependent dynamic tensile strength using the CEB-FIP and Malvar–Ross dynamic increase factor (DIF) models. This rate-dependent DCR provides a more physically accurate capacity estimate for seismic strain rates (10−4 to 10−1 s−1), potentially reducing unnecessary conservatism while maintaining safety. The implications for performance level classification and the triggering of onlinear analysis are discussed.