Evaluation of seismic reliability and multi level response reduction factor (R factor) for eccentric braced frames with vertical links

  • Mohsenian, Vahid (Seismic Geotechnical and High Performance Concrete Research Centre, Civil Engineering Department, Semnan Branch, Islamic Azad University) ;
  • Mortezaei, Alireza (Seismic Geotechnical and High Performance Concrete Research Centre, Civil Engineering Department, Semnan Branch, Islamic Azad University)
  • Received : 2018.01.27
  • Accepted : 2018.04.04
  • Published : 2018.06.25


Using vertical links in eccentric braced frames is one of the best passive structural control approaches due to its effectiveness and practicality advantages. However, in spite of the subject importance there are limited studies which evaluate the seismic reliability and response reduction factor (R-factor) in this system. Therefore, the present study has been conducted to improve the current understanding about failure mechanism in the structural systems equipped with vertical links. For this purpose, following definition of demand and capacity response reduction factors, these parameters are computed for three different buildings (4, 8 and 12 stories) equipped with this system. In this regards, pushover and incremental dynamic analysis have been employed, and seismic reliability as well as multi-level response reduction factor according to the seismic demand and capacity of the frames have been derived. Based on the results, this system demonstrates high ductility and seismic energy dissipation capacity, and using the response reduction factor as high as 8 also provides acceptable reliability for the frame in the moderate and high earthquake intensities. This system can be used in original buildings as lateral load resisting system in addition to seismic rehabilitation of the existing buildings.


  1. ABAQUS (2014), Version 6.14, ABAQUS Users Manual, SIMULIA World Headquarters, Rissing Sun Mills 166 Valley Street, Providence, RI 02909-2499, USA.
  2. Ang, A.H.S and Tang, W.H. (2007), Probability Concepts in Engineering: Emphasis on Applications to Civil and Environmental Engineering, Vol. 1, Wiley, 2nd Edition, USA.
  3. ATC (1995a), "Structural response modification factors", ATC-19 Report, Applied Technology Council, Redwood City, California.
  4. ATC (1996), Seismic Evaluation of Concrete Buildings, Vol. 1, ATC-40, Applied Technology Council, Redwood, CA.
  5. Baradaran, M.R., Hamzezarghani, F., Rastegari Ghiri, M. and Mirsanjari, Z. (2015), "The effect of vertical shear-link in improving the seismic performance of structures with eccentrically bracing systems", Int. J. Civil Environ. Eng., 9(8), 1078-1082.
  6. Bathaei, A. and Zahrai, S.M. (2017), "Investigation of the effects of vertical link beam length on steel structures residual displacement", Modares Civil Eng. J., 17(3), 47-60. (in Persian)
  7. Beheshti Aval, S.B. (2013), Seismic Rehabilitation of Existing Buildings, Vol. 1, K.N. Toosi University of Technology Press, Iran.
  8. Berahman, F. and Behnamfar, F. (2007), "Seismic fragility curves for un-anchored on-grade steel storage tanks: Bayesian approach", J. Earthq. Eng., 11(2), 166-192.
  9. Bertro, V.V (1989), "Evaluation of response reduction factors recommended by ATC and SEAOC", Proceedings of the 3rd U.S.Nat1 Conf. on Earthquake Engineering, South Carolina, 1663-1670.
  10. Bouwkamp, J., Vetr, M.G. and Ghamari, A. (2016), "An analytical model for inelastic cyclic response of eccentrically braced frame with vertical shear link (V-EBF)", Case Stud. Struct. Eng., 6, 31-44.
  11. Computers and Structures Inc. (CSI) (2015), Structural and Earthquake Engineering Software, ETABS, Extended Three Dimensional Analysis of Building Systems Nonlinear, Version 15.2.2, Berkeley, CA, USA.
  12. Computers and Structures Inc. (CSI) (2016), Structural and Earthquake Engineering Software, PERFORM-3D Nonlinear Analysis and Performance Assessment for 3-D Structures, Version 6.0.0, Berkeley, CA, USA.
  13. Daryan, A.S., Bahrampoor, H., Ziaei, M., Golafshar, A. and Assareh, M.A. (2008), "Seismic behavior of vertical shear links made of easy-going steel", Am. J. Eng. Appl. Sci., 1(4), 368-377.
  14. Duan, L. and Su, M. (2017), "Seismic testing of high-strength steel eccentrically braced frames with a vertical link", Proc. Inst. Civil Eng. Struct. Build., 170(11), 874-882.
  15. Fajfar, P. (2000), "A nonlinear analysis method for performance based seismic design", Earthq. Spectra, 116(3), 573-592.
  16. FEMA 356 (2000), Prestandard and Commentary for the Seismic Rehabilitation of Buildings, Prepared by the American Society of Civil Engineers for the Federal Emergency Management Agency, Washington D.C.
  17. Hancock, J., Watson-Lamprey, J., Abrahamson, N.A., Bommer, J.J., Markatis, A., McCoy, E. and Mendis, R. (2006) "An improved method of matching response spectra of recorded earthquake ground motion using wavelets", J. Earthq. Eng., 10, 67-89.
  18. Institute of National Building Regulations (2008), Design and construction of Steel Structures, Topic. 10, Ministry of Roads & Urban Development, Iran.
  19. Lia, S.P. and Biggs, J.M. (1980), "Inelastic response spectra for seismic building design", J. Struct. Div., ASCE, 106(6), 1295-1310.
  20. Lian, M. and Su, M. (2017), "Seismic performance of highstrength steel fabricated eccentrically braced frame with vertical shear link", J. Constr. Steel Res., 137, 262-285.
  21. Miranda, E. (1991), "Seismic evaluation & upgrading of existing buildings", A P.hd Thesis, University of California @ Berkeley.
  22. Mohsenian, V., Gharehbaghi, S.A. and Beheshti-Aval, S.B. (2016), "Seismic reliability assessment of two case-study tunnel form buildings considering the effect of soil-structure interaction," Bull. Earthq. Sci. Eng., 3(3), 11-29. (in Persian)
  23. Mortezaei, A. (2013), "Plastic hinge length of RC columns considering soil-structure interaction", Earthq. Struct., 5(6), 679-702.
  24. Mortezaei, A. and Ronagh, H.R. (2013), "Effectiveness of modified pushover analysis procedure for the estimation of seismic demands of buildings subjected to near-fault ground motions having fling step", Nat. Hazard. Earth Syst. Sci., 13(6), 1579-1593.
  25. PEER Ground Motion Database, Pacific Earthquake Engineering Research Center, Web Site:
  26. Permanent Committee for Revising the Standard 2800 (2014), Iranian Code of Practice for Seismic Resistant Design of Buildings, 4th Edition, Building and Housing Research Center, Tehran, Iran.
  27. Rahnavard, R., Hassanipour, A., Suleiman, M. and Mokhtati, A. (2017), "Evaluation on eccentrically braced frame with single and double shear panels", J. Build. Eng., 10, 13-25.
  28. Seki, M., Katsumata, H., Uchida, H. and Takeda, T. (1988), "Study on earthquake response of two-storied steel frame with Yshaped braces", Proceedings 9th World Conference on Earthquake Engineering, Tokyo-Kyoto, Japan.
  29. Shayanfar, M.A., Barkhordari, M.A. and Rezaeian, A.R. (2011), "Experimental study of cyclic behavior of composite vertical link in eccentrically braced frames", Steel Compos. Struct., 12(1), 13-29.
  30. Shome, N. and Cornell, C.A. (1999), "Probabilistic seismic demand analysis of nonlinear structures", Reliability of Marine Structures Report No: RMS-35, Civil and Environmental Engineering, Stanford University.
  31. Vamvatsikos, D. and Cornell, C.A. (2002), "Incremental dynamic analysis", Earthq. Eng. Struct. Dyn., 31(3), 491-514.
  32. Vetr, M.G., Ghamari, A. and Bouwkamp, J. (2017), "Investigating the nonlinear behavior of eccentrically braced frame with vertical shear links (V-EBF)", J. Build. Eng., 10, 47-59.
  33. Zahrai, S.M. and Mahroozadeh, Y. (2010), "Experimental study of using vertical link beam to improve seismic performance of steel buildings", J. Civil Surv. Eng., 44(3), 379-393.
  34. Zahrai, S.M. and Moslehi Tabar, A. (2013), "Analytical study on cyclic behavior of chevron braced frames with shear panel system considering post-yield deformation", Can. J. Civil Eng., 40(7), 633-643.
  35. Zahrai, S.M. and Parsa, A. (2015), "Effect of flange width of vertical link beam on cyclic behavior of chevron braced steel frames", J. Seismol. Earthq. Eng., 17(4), 281-292.
  36. Zareian, F., Krawinkler, H., Ibarra, L. and Lignos, D. (2010), "Basic concepts and performance measures in prediction of collapse of buildings under earthquake ground motions", Struct. Des. Tall Spec. Build., 19, 167-181.