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The questionable effectiveness of code accidental eccentricity

  • Ouazir, Abderrahmane (Department of Civil Engineering, College of Engineering, University of Ha'il) ;
  • Hadjadj, Asma (Department of Interior Designl Engineering, College of Engineering, University of Ha'il) ;
  • Gasmi, Hatem (Department of Civil Engineering, College of Engineering, University of Ha'il) ;
  • Karoui, Hatem (LR14ES03 Laboratoire d'Ingenierie Geotechnique, Ecole Nationale d'Ingenieurs de Tunis, Universite de Tunis El Manar)
  • 투고 : 2021.02.22
  • 심사 : 2022.04.12
  • 발행 : 2022.07.10

초록

The need to account for accidental torsion in seismic design is no longer debatable, however, the seismic codes' requirement for accidental eccentricity has recently faced criticism. In order to get as close to real conditions as possible, this study investigated the impact of accidental torsion in symmetric RC multistory buildings caused by one of its many sources, the torsional earthquake component, and compared the results to those obtained by using the accidental eccentricity recommended by the codes (shifting the center of mass). To cover a wide range of frequencies and site conditions, two types of torsion seismic components were used: a recorded torsion accelerogram and five others generated using translation accelerograms. The main parameters that govern seismic responses, such as the number of stories (to account for the influence of all modes of vibration) and the frequency ratio (Ω) variation, were studied in terms of inter-story drift and displacement responses, as well as torsional moment. The results show that the eccentricity ratio of 5% required by most codes for accidental torsion should be reexamined and that it is prudent for computer analysis to use the static moment approach to implement the accidental eccentricity while waiting for new seismic code recommendations on the subject.

키워드

과제정보

The authors are thankful to the Deanship of Scientific Research at the University of Ha'il, Saudi Arabia for the financial support under the contract (RG-20 026).

참고문헌

  1. American Society of Civil Engineers (ASCE) (2013), Minimum Design Loads for Buildings and Other Structures, ASCE/SEI 7-10 Edition, American Society of Civil Engineers, Reston, VA.
  2. Anagnostopoulos, S.A., Kyrkos, M.T. and Stathopoulos, K.G. (2015b), "Earthquake induced torsion in buildings: critical review and state of the art", Earthq. Struct., 8(2), 305-377. https://doi.org/10.12989/eas.2015.8.2.305.
  3. Anagnostopoulos, S.A., Kyrkos, M.T., Papalymperi, A. and Plevri, E. (2015a), "Should accidental eccentricity be eliminated from Eurocode 8?", Earthq. Struct., 8(2), 463-484. https://doi.org/10.12989/eas.2015.8.2.463.
  4. ASCE (2013), Minimum Design Loads for Buildings and other Structures, American Society of Civil Engineers, USA.
  5. Basu, D., Whittaker, A.S. and Constantinou, M.C. (2012), "Estimating rotational components of ground motion using data recorded at a single station", J. Eng. Mech., 138(9), 1141-1156. https://doi.org/10.1061/(ASCE)EM.1943-7889.0000408.
  6. Basu, D., Whittaker, A.S. and Constantinou, M.C. (2015), "Characterizing rotational components of earthquake ground motion using a surface distribution method and response of sample structures", Eng. Struct., 99, 685-707. https://doi.org/10.1016/j.engstruct.2015.05.029.
  7. de la Llera, J.C. and Chopra, A.K. (1994), "Using accidental eccentricity in code-specified static and dynamic analyses of buildings", Earthq. Eng. Struct. Dyn., 23(9), 947-967. https://doi.org/10.1002/eqe.4290230903.
  8. De La Llera, J.C. and Chopra, A.K. (1995), "Estimation of accidental torsion effects for seismic design of buildings", J. Struct. Eng., 121(1), 102-114. https://doi.org/10.1061/(ASCE)0733-9445(1995)121:1(102).
  9. Debock, D., Hohener, C. and Valley, M. (2019), Does Accidental Torsion Prevent Collapse? How Collapse Potential is Affected by the Method of Considering Accidental Torsion, Structure Mag., March.
  10. Debock, D.J., Liel, A.B., Haselton, C.B., Hooper, J.D. and Henige, R.A. (2014), "Importance of seismic design accidental torsion requirements for building collapse capacity", Earthq. Eng. Struct. Dyn., 43(6), 831-850. https://doi.org/10.1002/eqe.2375.
  11. Eurocode 8 (2005), Design of Structures for Earthquake Resistance-Part 1: General Rules, Seismic Actions and Rules for Buildings, European Committee for Standardization; Brussels, Belgium.
  12. Lee, V.W. and Trifunac, M.D. (1985), "Torsional accelerograms", Int. J. Soil Dyn. Earthq. Eng., 4(3), 132-139. https://doi.org/10.1016/0261-7277(85)90007-5.
  13. Lee, V.W. and Trifunac, M.D. (1987), "Rocking strong earthquake accelerations", Soil Dyn. Earthq. Eng., 6(2), 75-89. https://doi.org/10.1016/0267-7261(87)90017-0.
  14. Li, H., Sun, L. and Wang, S. (2004), "Improved approach for obtaining rotational components of seismic motion", Nucl. Eng. Des., 232(2), 131-137. https://doi.org/10.1016/j.nucengdes.2004.05.002.
  15. Lin, J., Wang, W. and Tsai, K. (2016), "Suitability of using the torsional amplification factor to amplify accidental torsion", Eng. Struct., 127, 1-17. https://doi.org/10.1016/j.engstruct.2016.08.042.
  16. N.S.Z. 1170.5:2004 (2004), Structural Design Actions, Part 5: Earthquake Actions, New Zealand.
  17. National Building Code of Canada (NBCC) (2005), National Research Council of Canada, Canada.
  18. Nazarov, Y.P., Poznyak, E. and Filimonov, A.V. (2015), "A brief theory and computing of seismic ground rotations for structural analyses", Soil Dyn. Earthq. Eng., 71, 31-41. https://doi.org/10.1016/j.soildyn.2015.01.013.
  19. Newmark, N.M. (1975), "Torsion in symmetrical buildings", Proceeding of World Conference on Earthquake Engineering., January.
  20. Ouazir, A., Hadjadj, A. and Benanane, A. (2017), "Numerical study on the effects of seismic torsional component on multistory buildings", Earthq. Struct., 13(1), 9-15. https://doi.org/10.12989/eas.2017.13.1.009.
  21. Ouazir, K., Benanane, A., Ouazir, A., Ouazir, M. and Hadjadj, A. (2021), "Rocking seismic excitations effect on inelastic response of reinforced concrete building with soft-story", J. Mater. Eng. Struct., 8(2), 197-207.
  22. Perron, V., Hollender, F., Mariscal, A., Theodoulidis, N., Andreou, C., Bard, P., Cornou, C., Cottereau, R., Cushing, E.M., Frau, A., Hok, S., Konidaris, A., Langlaude, P., Laurendeau, A., Savvaidis, A. and Svay, A. (2018), "Accelerometer, velocimeter dense-array, and rotation sensor datasets from the Sinaps@ postseismic survey (Cephalonia 2014-2015 aftershock sequence)", Seismol. Res. Lett., 89(2A), 678-687. https://doi.org/10.1785/0220170125.
  23. Sollberger, D., Igel, H., Schmelzbach, C., Edme, P., Van Manen, D., Bernauer, F., Yuan, S., Wassermann, J., Schreiber, U. and Robertsson, J.O.A. (2020), "Seismological processing of six degree-of-freedom ground-motion data", Sensor. (Basel, Switzerland), 20(23), 6904. https://doi.org/10.3390/s20236904.
  24. Yin, J., Nigbor, R.L., Chen, Q. and Steidl, J. (2016), "Engineering analysis of measured rotational ground motions at GVDA", Soil Dyn. Earthq. Eng., 87, 125-137. https://doi.org/10.1016/j.soildyn.2016.05.007.
  25. Zembaty, Z., Mutke, G., Nawrocki, D. and Bobra, P. (2017), "Rotational ground motion records from induced seismic events", Seismol. Res. Lett., 88(1), 13-22. https://doi.org/10.1785/0220160131.