ICOLD Committee on Computational Aspects of Analysis and Design of Dams organized the 15th International Benchmark Workshop in Milan, Italy, in September 2019. Theme A of the workshop is related to a seismic analysis of Pine Flat Dam. The study proposed in the Milan workshop is a continuation of investigations initiated by the United States Society on Dams Concrete Dams Committee and Earthquakes Committee during the workshop Evaluation of Numerical Models and Input Parameters in the Analysis of Concrete Dams held in Miami, Florida, on May 3, 2018. The purpose of Theme A investigations is to define uncertainties in numerical analyses of concrete dams in a focused, systematic, and controlled way with collaborative participation from the international dam industry and academia. The objectives of these investigations are to identify key uncertainties that may lead to differences among analysis results, to advance best practices for analyses of concrete dams, and to determine further research needs. Overall, 27 teams, representing 16 countries, submitted solutions to the formulated six study cases for Theme A, together with technical papers that documented the methods and approaches used in the analyses. The summary of the benchmark studies can serve as a reference in verification of computational models used in seismic analysis of concrete dams.