Efficient approach for the reliability-based design of linear damping devices for seismic protection of buildings

This paper presents an efficient reliability-based methodology for the seismic design of viscous/viscoelastic dissipative devices in independent and/or coupled buildings. The proposed methodology is consistent with modern performance-based earthquake engineering frameworks and explicitly considers the uncertainties affecting the seismic input and the model parameters, as well as the correlation between multiple limit states. The proposed methodology casts the problem of the dampers' design for a target performance objective in the form of a reliability-based optimization problem with a probabilistic constraint. The general approach proposed in this study is specialized to stochastic seismic excitations and performance levels for which the structural behavior can be assumed as linear elastic. Under these conditions, the optimization problem is solved efficiently by taking advantage of existing analytical techniques for estimating the system reliability. This analytical design solution is an approximation of the optimal design and can be used as a hot-start point for simulation- based techniques, which can be employed to find the optimal design solution. An efficient correction formula is proposed to obtain an improved design solution that is generally sufficiently close for engineering purposes to the optimal design solution obtained from significantly more-computationally-expensive simulation-based techniques. The proposed design methodology is illustrated and validated by considering two steel buildings modeled as linear elastic multiple-degree-of-freedom systems for different linear damper properties and collocation, for both independent and coupled configurations. (C) 2015 American Society of Civil Engineers.