Seismic Retrofitting of Eccentrically Braced Frames by Rocking Walls and Viscous Dampers

Abstract:

A design procedure for seismic retrofitting of eccentrically braced frames (EBFs) by rocking walls and viscous dampers is proposed. The design procedure is founded on the displacement-based approach. The top displacement capacity of the building is evaluated based on the displacement ductility capacity of links and on a rigid lateral deformed configuration of the structure promoted by the rocking walls. The equivalent viscous damping ratio capacity of the EBFs with rocking walls is calculated by semi-empirical relationships specifically calibrated for EBFs with links characterized by mechanical length lower than 2.0. Additional damping is provided by linear viscous dampers. The design internal forces of the rocking walls are evaluated based on the seismic effects of more than one mode of vibration. The effectiveness of the design procedure is verified by means of a case study.

• Periodical: Key Engineering Materials (Volume 763)
• Pages: 1105-1112
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.763.1105
• Online since: February 2018
• Authors: Francesca Barbagallo, Melina Bosco*, Aurelio Ghersi, Edoardo Michele Marino, Pier Paolo Rossi
• Keywords: Braced Frame, Displacement-Based Approach, Retrofit, Rocking Wall

References

[1] L. Di Sarno, A.S. Elnashai, Seismic retrofitting of steel and composite building structures. Mid-America Earthquake Center, CD Release 02-01, University of Illinois at Urbana-Champaign (2002).

[2] D.J. Marriott, S. Pampanin, D. Bull, A. Palermo, Dynamic testing of precast, post-tensioned rocking wall systems with alternative dissipating solutions, Proc. New Zealand Society for Earthquake Engineering, Napier (2008).

DOI: 10.5459/bnzsee.41.2.90-103

[3] Z. Qu, A. Wada, S. Motoyui, H. Sakata, S. Kishiki, Pin-supported walls for enhancing the seismic performance of building structures, Earthquake Engineering & Structural Dynamics 41 (2012) 2075-(2091).

DOI: 10.1002/eqe.2175

[4] M. Bosco, P.P. Rossi, A design procedure for dual eccentrically braced systems: analytical formulation, Journal of constructional steel research 80 (2013) 440-452.

DOI: 10.1016/j.jcsr.2012.09.019

[5] M. Bosco, E.M. Marino, P.P. Rossi, Modelling of steel link beams of short, intermediate or long length, Engineering structures 84 (2015) 406-418.

DOI: 10.1016/j.engstruct.2014.12.003

[6] F. Amara, M. Bosco, E.M. Marino, P.P. Rossi, An accurate strength amplification factor for the design of SDOF systems with PΔ effects, Earthquake Engineering & Structural Dynamics 43 (2014) 589–611.

DOI: 10.1002/eqe.2361

[7] M. Bosco, E.M. Marino, P.P. Rossi, Influence of modelling of steel link beams on the seismic response of EBFs, Engineering structures 127 (2016) 459-474.

DOI: 10.1016/j.engstruct.2016.08.062