Performance-based seismic risk assessment for buildings equipped with linear and nonlinear viscous dampers

• A methodology for seismic risk assessment of viscously damped buildings is proposed.
• Stochastic analytical techniques are used to efficiently estimate the risk.
• Limit states correlation and model parameter uncertainty significantly affect the risk.
• Coupling adjacent buildings with viscous dampers is an efficient retrofit technique.
• Linear and nonlinear viscous dampers can yield similar risk reductions.

This paper introduces an efficient methodology for assessing the seismic risk of structural systems equipped with linear and nonlinear viscous damping devices while accounting for the uncertainties affecting both seismic input and model parameters. The proposed methodology employs a combination of efficient and accurate analytical and simulation techniques to estimate the probabilistic properties of the structural response under a seismic input modeled as a non-stationary stochastic process.The effectiveness of the proposed methodology is illustrated through a parametric study, with respect to the dampers’ properties, of the performance of two adjacent steel buildings connected by linear and nonlinear viscous dampers. The results of the study provide useful information regarding the accuracy of the approximations introduced by the proposed reliability assessment approach, and the effectiveness of the added dampers in reducing the system seismic risk.