Risk‐based optimal retrofit of a tall steel building by using friction dampers

Abstract

SUMMARY Friction dampers, whose configuration is optimized on the basis of the probabilistic seismic loss associated with a building's damage due to ground motion, were utilized in this study to optimally retrofit a 15‐story steel structure. In line with the concept of performance‐based earthquake engineering (PBEE), a decision‐making procedure based on the monetary seismic loss was incorporated for optimizing the dampers' configuration. A nonlinear numerical model was initially established for representing the structure. In this regard, a brace–damper system was modeled with the buckling of brace elements being addressed accurately and by representing the friction damper's load–displacement relationship on the basis of laboratory evidences. By monitoring the structural deformations in two different response levels, two patterns were established for the distribution of the dampers' strengths throughout the structure, and a number of retrofit alternatives were proposed subsequently. By using incremental dynamic analysis and following the PBEE methodology, the annualized loss (AL), which accounts for all potential damage states in the building and a broad range of seismic intensities, was calculated for each alternative frame. The AL is regarded as a decision variable upon which the best damper configuration is selected. Revealing conclusions were finally made regarding optimal configuration of the damper–brace system. Copyright © 2011 John Wiley & Sons, Ltd.

Experimental Study on Seismic Retrofitting of Reinforced Concrete Frames Using Welded Concrete-Filled Steel Tubes

“…Therefore, a number of studies have been conducted on seismic retrofitting methods that can mitigate the disadvantages of the existing seismic retrofitting approaches. The research has focused on seismic retrofitting methods using fiber-reinforced polymer (FRP) [2,[4][5][6][7][8], steel beams [3,9], and dampers [10][11][12][13][14]. Although new seismic retrofitting methods have been studied to improve the existing retrofitting methods, there are some drawbacks; the drawbacks of the seismic retrofitting method using FRP are the relatively high cost of epoxies, inability to attach on wet surfaces, difficulty conducting post-earthquake assessment of the damage suffered by the reinforced concrete that is behind the undamaged FRP jackets, and so on [4].…”

Seismic retrofit design and risk assessment of an irregular thermal power plant building

“…The resilience of a building structure can be enhanced by using isolation techniques, supplemental damping systems, or a combination of these . By strategically using these techniques, structural repair and/or replacement of the added devices in the aftermath of an earthquake can be done in a short time.…”

“…In addition, the performance‐based design theory was applied to innovative structural systems like self‐centering moment frame and buildings equipped with damping systems . Tafakori et al performed risk‐based retrofit design on an existing tall steel building. And eight retrofit alternatives were compared in terms of seismic risk and annual loss.…”

Seismic response analysis of frame with friction damper

“…Finally, the influence of important parameters on the maximum displacement of friction damper is also investigated for its effective design in coupling the adjacent structures. In Tafakori et al (2013), friction dampers, whose configuration is optimized on the basis of the probabilistic seismic loss associated with a building's damage due to ground motion, were utilized in this study to optimally retrofit a 15-story steel structure. By monitoring the structural deformations in two different response levels, two patterns were established for the distribution of the dampers' strengths throughout the structure, and a number of retrofit alternatives were proposed subsequently.…”