- Volume 15 Issue 5
DOI QR Code
Probabilistic seismic assessment of mega buckling-restrained braced frames under near-fault ground motions
- Veismoradi, Sajad (School of Civil Engineering, Iran University of Science & Technology) ;
- Darvishan, Ehsan (Roudehen Branch, Islamic Azad University)
- Received : 2017.05.12
- Accepted : 2018.09.05
- Published : 2018.11.25
Buckling-restrained braces are passive control devices with high level of energy dissipation ability. However, they suffer from low post-yield stiffness which makes them vulnerable to severe ground motions, especially near-field earthquakes. Among the several methods proposed to improve resistance of BRB frames, mega-brace configuration can be a solution to increase frame lateral strength and stiffness and improve distribution of forces to prevent large displacement in braces. Due to the limited number of research regarding the performance of such systems, the current paper aims to assess seismic performance of BRB frames with mega-bracing arrangement under near-field earthquakes via a detailed probabilistic framework. For this purpose, a group of multi-story mega-BRB frames were modelled by OpenSEES software platform. In the first part of the paper, simplified procedures including nonlinear pushover and Incremental Dynamic Analysis were conducted for performance evaluation. Two groups of near-fault seismic ground motions (Non-pulse and Pulse-like records) were considered for analyses to take into account the effects of record-to-record uncertainties, as well as forward directivity on the results. In the second part, seismic reliability analyses are conducted in the context of performance based earthquake engineering. Two widely-known EDP-based and IM-based probabilistic frameworks are employed to estimate collapse potential of the structures. Results show that all the structures can successfully tolerate near-field earthquakes with a high level of confidence level. Therefore, mega-bracing configuration can be an effective alternative to conventional BRB bracing to withstand near-field earthquakes.
- AISC 341-05 (2005), Seismic Provisions for Steel Structural Buildings, American Institute of Steel Construction, Inc., Chicago.
- Ariyaratana, C. and Fahnestock, L.A. (2011), "Evaluation of buckling-restrained braced frame seismic performance considering reserve strength", Eng. Struct., 33(1), 77-89. https://doi.org/10.1016/j.engstruct.2010.09.020
- Baker, J.W. (2007), "Quantitative classification of near-fault ground motions using wavelet analysis", Bull. Seismol. Soc. Am., 97(5), 1486-1501. https://doi.org/10.1785/0120060255
- BC-97 (1997), Uniform Building Code, International Council of Building Officials, USA.
- Black, C., Aiken, I.D. and Makris, N. (2002), "Component testing, stability analysis, and characterization of buckling-restrained unbonded braces (TM)", Pacific Earthquake Engineering Research Center.
- Di Sarno, L. and Elnashai, A.S. (2009) "Bracing systems for seismic retrofitting of steel frames", J. Constr. Steel Res., 65(2), 452-465. https://doi.org/10.1016/j.jcsr.2008.02.013
- Eskandari, R., Vafaei, D., Vafaei, J. and Shemshadian, M.E. (2017), "Nonlinear static and dynamic behavior of reinforced concrete steel-braced frames", Earthq. Struct., 12(2), 191-200. https://doi.org/10.12989/eas.2017.12.2.191
- Fahnestock, L.A., Ricles, J.M. and Sause, R. (2007), "Experimental evaluation of large-scale buckling-restrained braced frame", J. Struct. Eng., 133(9), 1205-1214. https://doi.org/10.1061/(ASCE)0733-9445(2007)133:9(1205)
- FEMA P-695 (2009), Quantification of Building Seismic Performance Factors, Federal Emergency Management Agency.
- Guo, Y.L., Zhou, P., Wang, M.Z., Pi, Y.L., Bradford, M.A. and Tong, J.Z. (2017), "Experimental and numerical studies of hysteretic response of triple-truss-confined buckling-restrained braces", Eng. Struct., 148, 157-174. https://doi.org/10.1016/j.engstruct.2017.06.058
- Jalayer, F. and Cornell, C.A. (2003), "A technical framework for probability-based demand and capacity factor (DCFD) seismic formats", RMS Technical Rep. No. 43 to the PEER Center, Dept. of Civil and Environmental Engineering, Stanford Univ., Stanford.
- Kalkan, E. and Kunnath, S.K. (2006), "Effects of fling step and forward directivity on seismic response of buildings", Earthq. Spectra, 22(2), 367-390. https://doi.org/10.1193/1.2192560
- Khorami, M., Alvansazyazdi, M., Shariati, M., Zandi, Y., Jalali, A. and Tahir, M. (2017), "Seismic performance evaluation of buckling restrained braced frames (BRBF) using incremental nonlinear dynamic analysis method (IDA)", Earthq. Struct., 13(6), 531-538. https://doi.org/10.12989/EAS.2017.13.6.531
- Kim, J., Park, J., Shin, S.W. and Min, K.W. (2009) "Seismic performance of tubular structures with buckling restrained braces", Struct. Des. Tall Spec. Build., 18(4), 351-370. https://doi.org/10.1002/tal.420
- Lopez, W.A. and Sabelli, R. (2004), "Seismic design of bucklingrestrained braced frames", Steel TIPS 07.2004, Structural Steel Educational Council.
- Mazzoni, S., McKenna, F., Scott, M.H. and Fenves, G.L. (2006), "The Open System for Earthquake Engineering Simulation (OpenSEES) user command-language manual".
- Mortezaei, A., Ronagh, H.R. and Kheyroddin, A. (2010), "Seismic evaluation of FRP strengthened RC buildings subjected to nearfault ground motions having fling step", Compos. Struct., 92(5), 1200-1211. https://doi.org/10.1016/j.compstruct.2009.10.017
- Richards, P.W. and Miller, D.J. (2014), "High-yield-drift steel moment frames", Proceedings of the 10th U.S. National Conference on Earthquake Engineering, Anchorage, Alaska.
- Sheikh, H. and Massumi, A. (2014) "Effects of bracing configuration on seismic behavior of tall steel structures subjected to earthquake ground motions", Proceedings of the 10th U.S. National Conference on Earthquake Engineering, Anchorage, Alaska.
- Soleimani Amiri, F., Ghodrati Amiri, G. and Razeghi, H. (2013), "Estimation of seismic demands of steel frames subjected to near-fault earthquakes having forward directivity and comparing with pushover analysis results", Struct. Des. Tall Spec. Build., 22(13), 975-988. https://doi.org/10.1002/tal.747
- Stewart, J.P., Chiou, S.J., Bray, J.D., Graves, R.W., Somerville, P.G. and Abrahamson, N.A. (2002), "Ground motion evaluation procedures for performance-based design", Soil Dyn. Earthq. Eng., 22(9-12), 765-772. https://doi.org/10.1016/S0267-7261(02)00097-0
- Vafaei, D. and Eskandari, R. (2015), "Seismic response of mega buckling-restrained braces subjected to fling-step and forwarddirectivity near-fault ground motions", Struct. Des. Tall Spec. Build., 24(9), 672-686. https://doi.org/10.1002/tal.1205
- Vamvatsikos, D. and Cornell, C.A. (2002), "Incremental dynamic analysis", Earthq. Eng. Struct. Dyn., 31(3), 491-514. https://doi.org/10.1002/eqe.141
- Veismoradi, S., Amiri, G.G. and Darvishan, E. (2016), "Probabilistic seismic assessment of Buckling Restrained Braces and Yielding Brace Systems", Int. J. Steel Struct., 16(3), 831-843. https://doi.org/10.1007/s13296-015-0073-5
- Yu, X., Ji, T. and Zheng, T. (2015), "Relationships between internal forces, bracing patterns and lateral stiffnesses of a simple frame", Eng. Struct., 89, 147-161. https://doi.org/10.1016/j.engstruct.2015.01.030
- Zahiri-Hashemi, R., Kheyroddin, A. and Farhadi, B. (2013), "Effective number of mega-bracing, in order to minimize shear lag", Struct. Eng. Mech., 48(2), 173-193. https://doi.org/10.12989/sem.2013.48.2.173
- Zareian, F. and Krawinkler, H. (2007), "Assessment of probability of collapse and design for collapse safety", Earthq. Eng. Struct. Dyn., 36(13), 1901-1914. https://doi.org/10.1002/eqe.702
- 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(1-2), 167-181. https://doi.org/10.1002/tal.546