P-Delta Effect on Residual Displacement and Collapse Capacity of SDOF Systems during Long and Short Duration Earthquakes

Document Type : Original Article

Authors

1 Babol Noshirvani University of Technology

2 Faculty of civil engineering department/ Babol Noshirvani University of Technology

3 Faculty of Civil Engineering, Babol Noshirvani University of Technology, Babol, Iran

Abstract

In structural analysis, P-Delta effect refers to the changes in internal forces due to P-Delta moment which can be found by multiplying gravity load (P) by the lateral displacement of structure for earthquake lateral load (Delta). The influence of P-Delta in elastic response of structures is ignorable, but P-Delta effect should be given more attention when the structure responds in inelastic range. On the other hand, the influence of ground motion duration is magnified when P-Delta effect is considered in the structural analysis. In this paper, to consider the simultaneous effect of ground motion duration and P-Delta effect, an algorithm is implemented in MATLAB which employs OPENSEES for linear and nonlinear dynamic analysis of elasto-plastic systems subjected to long- and short-duration records. The analysis results indicate that the frequency of structural collapse for long-duration ground motions is about twice of short-duration ground motions. The frequency of collapse also increases when ductility and stability index increase, but decreases when the period of structure increases. Furthermore, the increase of ground motion duration has no influence on the residual displacement of structures, but nonlinear behavior of structures and gravity load effect increase the residual displacements.

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Main Subjects


[1] Deierlein, G. G., Reinhorn, A. M., & Willford, M. R. (2010). “Nonlinear structural analysis for seismic design”, NEHRP seismic design technical brief, 4, 1-36.
[2] Montgomery, C. J. (1981). “Influence of P–delta effects on seismic design”, Canadian Journal of Civil Engineering, 8(1), 31-43.
[3] Belleri, A., Torquati, M., Marini, A., & Riva, P. (2017). “A novel framework to include P-Δ effects in displacement-based seismic assessment”, Journal of Earthquake Engineering, 21(3), 486-492.
[4] MacRae, G. A. (1994). “P-Δ effects on single-degree-of-freedom structures in earthquakes”, Earthquake spectra, 10(3), 539-568.
[5] Bravo-Haro, M. A., Liapopoulou, M., & Elghazouli, A. Y. (2020). “Seismic collapse capacity assessment of SDOF systems incorporating duration and instability effects”, Bulletin of Earthquake Engineering, 18(7), 3025-3056.
[6] Paulay, T., & Priestley, M. N. (1992). Seismic design of reinforced concrete and masonry buildings. Print ISBN: 9780471549154| Online ISBN: 9780470172841| DOI:10.1002/9780470172841.
[7] Priestley, M. N., Calvi, G. M., & Kowalsky, M. J. (2007). “Displacement based seismic design of structures”, In NZSEE conference, 1-23.
[8] Wei, B., Xu, Y., & Li, J. (2012). “Treatment of P-Δ effects in displacement-based seismic design for SDOF systems”, Journal of Bridge Engineering, 17(3), 509-518.
[9] MacRae, G. A., Priestley, M. J. N., & Tao, J. (1993). “P-Delta design in seismic regions”, Department of Applied Mechanics & Engineering Sciences, University of California, San Diego.
[10] American Society of Civil Engineers. (2017). Minimum design loads and associated criteria for buildings and other structures. American Society of Civil Engineers.
[11] Rosenblueth, E. (1965). “Slenderness effects in buildings”, Journal of the Structural Division, 91(1), 229-252.
[12] Code, P. (2005). Eurocode 8: Design of structures for earthquake resistance-part 1: general rules, seismic actions and rules for buildings. Brussels: European Committee for Standardization.
[13] Federal Emergency Management Agency. (2003). NEHRP recommended provisions for seismic regulations for new buildings and other structures. FEMA.
[14] AASHTO, G. E. C. (2011). Guide specifications for LRFD seismic bridge design. LRFDSEIS-2.
[15] Bernal, D. (1987). “Amplification factors for inelastic dynamic p–Δ effects in earthquake analysis”, Earthquake Engineering & Structural Dynamics, 15(5), 635-651.
[16] Pourali, N., Khosravi, H., & Dehestani, M. (2019). “An investigation of P-delta effect in conventional seismic design and direct displacement-based design using elasto-plastic SDOF systems”, Bulletin of Earthquake Engineering, 17(1), 313-336.
[17] Paulay, T. (1978). “A consideration of P-delta effects in ductile reinforced concrete frames”, Bulletin of the New Zealand society for earthquake engineering, 11(3), 151-160.
[18] Chandramohan, R., Baker, J. W., & Deierlein, G. G. (2016). “Quantifying the influence of ground motion duration on structural collapse capacity using spectrally equivalent records”, Earthquake Spectra, 32(2), 927-950.
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