Earthquakes and Structures

  • 제8권2호
  • /
  • Pages.379-399
  • /
  • 2015
  • /
  • 2092-7614(pISSN)
  • /
  • 2092-7622(eISSN)
테크노프레스 (Techno-Press)
권호 표지
DOI QR코드

DOI QR Code

Torsional effects due to concrete strength variability in existing buildings

  • De Stefano, M. (Department of Architecture (DiDA), University of Florence) ;
  • Tanganelli, M. (Department of Architecture (DiDA), University of Florence) ;
  • Viti, S. (Department of Architecture (DiDA), University of Florence)
  • 투고 : 2014.09.17
  • 심사 : 2014.11.15
  • 발행 : 2015.02.25
⟨ 이전 논문 다음 논문 ⟩

초록

Existing building structures can easily present material mechanical properties which can largely vary even within a single structure. The current European Technical Code, Eurocode 8, does not provide specific instructions to account for high variability in mechanical properties. As a consequence of the high strength variability, at the occurrence of seismic events, the structure may evidence unexpected phenomena, like torsional effects, with larger experienced deformations and, in turn, with reduced seismic performance. This work is focused on the torsional effects related to the irregular stiffness and strength distribution due to the concrete strength variability. The analysis has been performed on a case-study, i.e., a 3D RC framed 4 storey building. A Normal distribution, compatible to a large available database, has been taken to represent the concrete strength domain. Different plan layouts, representative of realistic stiffness distributions, have been considered, and a statistical analysis has been performed on the induced torsional effects. The obtained results have been compared to the standard analysis as provided by Eurocode 8 for existing buildings, showing that the Eurocode 8 provisions, despite not allowing explicitly for material strength variability, are conservative as regards the estimation of structural demand.

키워드

참고문헌

  1. Anagnostopoulos, S.A., Alexopoulou, C. and Kyrkos, M.T. (2009), "An answer to an important controversy and the need for caution when using simple models to predict inelastic earthquake response of buildings with torsion", Earthq. Eng. Struct. Dyn., 39(5), 521-540. https://doi.org/10.1002/eqe.957
  2. Anagnostopoulos, S.A., Kyrkos, M.T. and Stathopoulos, K.G. (2013), "Earthquake induced torsion in buildings: critical review and state of art", Proceedings of the ASEM13, Jeju, Korea.
  3. Applied Technology Council (2000), Prestandard and commentary for the seismic rehabilitation of buildings, published by the Federal Emergency Management Agency, FEMA-356, Washington, D.C..
  4. Bhatt, C. and Bento, R. (2014), "The extended adaptive capacity spectrum method for the seismic assessment of plan asymmetric buildings", Earthq. Spectra, 30(2), 683-703. https://doi.org/10.1193/022112EQS048M
  5. Bosco, M., Ghersi, A. and Marino, E.M. (2009), "On the evaluation of seismic response of structures", Nonlin. Stat. Meth. Earthq. Eng. Stru. Dyn., 38(13), 1465-1482. https://doi.org/10.1002/eqe.911
  6. Bosco, M., Ghersi, A. and Marino, E.M. (2012), "Corrective eccentricities for assessment by nonlinear static analysis method of 3D structures subjected to bidirectional ground motions", Earth. Eng. Struc. Dyn., 41, 1751-1773. https://doi.org/10.1002/eqe.2155
  7. Bosco, M., Marino, E. and Rossi, P.P. (2013), "An analytical method for the evaluation of the in-plan irregularity of non-regularly asymmetric buildings", Bul. Earthq. Eng., 11, 1423-1455. https://doi.org/10.1007/s10518-013-9438-3
  8. Bugeja, M.N., Thambiratnam, D.P., Brameld, G.H. (1999), "The influence of stiffness and strength eccentricities on the inelastic earthquake response of asymmetric structures", Eng. Struct., 21(9), 856-863. https://doi.org/10.1016/S0141-0296(98)00035-2
  9. Chopra, A.K. and Goel, R.K. (2002), "A modal pushover analysis procedure for estimating seismic demand for buildings", Earth. Eng. Struct. Dyn., 31(3), 561-582. https://doi.org/10.1002/eqe.144
  10. Cosenza, E. and Monti, G. (2009), "Assessment and reduction of the vulnerability of existing reinforced concrete buildings", Atti Convegno Finale ReLuis, 51-110.
  11. Cristofaro, M.T. (2009), "Metodi di valutazione della resistenza a compressione del calcestruzzo di strutture in c.a. esistenti", PhD Dissertation, Universita di Firenze.
  12. Cristofaro, M.T., D'Ambrisi, A., De Stefano, M., Pucinotti, R. and Tanganelli, M. (2012), "Studio sulla dispersione dei valori di resistenza a compressione del calcestruzzo di edifici esistenti", Il giornale delle prove non distruttive, monitoraggio, diagnostica., 2, 32-39.
  13. Cristofaro, M.T., Pucinotti, R., Tanganelli, M. and De Stefano, M. (2015), "The dispersion of concrete compressive strength of existing buildings", Computational Methods, Seismic Protection, Hybrid Testing and Resilience in Earthquake Engineering, Eds. Cimellaro, G.P. et al., Geotechnical, Geological and Earthquake Engineering, 33, Springer International Publishing, Switzerland.
  14. D'Ambrisi, A., De Stefano, M. and Tanganelli, M. (2009), "Use of pushover analysis for predicting seismic response of irregular buildings: a case study", J. Earthq. Eng., 13, 1089-1100. https://doi.org/10.1080/13632460902898308
  15. D'Ambrisi, A., De Stefano, M., Tanganelli, M. and Viti, S. (2013a), "Sensitivity of seismic performance of existing framed RC structures to irregular mechanical properties", Seismic Behaviour and Design of Irregular and Complex Civil Structures, Eds. O. Lavan and M. De Stefano, Geotechnical, Geological and Earthquake Engineering 24, DOI 10.1007/978-94-007-5377-8_5, Springer Science + Business Media Dordrecht.
  16. D'Ambrisi, A., De Stefano, M., Tanganelli, M. and Viti, S. (2013b), "The effect of common irregularities on the seismic performance of existing RC framed buildings", Seismic Behaviour and Design of Irregular and Complex Civil Structures, Eds. O. Lavan and M. De Stefano, Geotechnical, Geological and Earthquake Engineering 24, DOI 10.1007/978-94-007-5377-8_4, Springer Science + Business Media Dordrecht.
  17. De Stefano, M. Tanganelli, M. and Viti, S. (2013a), "Effect of the variability in plan of concrete mechanical properties on the seismic response of existing RC framed structures", Bul. Earthq. Eng., 11, 1049-1060. https://doi.org/10.1007/s10518-012-9412-5
  18. De Stefano, M. Tanganelli, M. and Viti, S. (2013b), "On the variability of concrete strength as a source of irregularity in elevation for existing RC buildings: a case study", Bul. Earth. Eng., 11, 1711-1726. https://doi.org/10.1007/s10518-013-9463-2
  19. De Stefano, M. Tanganelli, M. and Viti, S. (2014), "Variability in concrete mechanical properties as a source of in-plan irregularity for existing RC framed structures", Eng, Struct., 59, 161-172. https://doi.org/10.1016/j.engstruct.2013.10.027
  20. De Stefano, M. Tanganelli, M. and Viti, S. (2015), "Concrete strength variability as a source of irregularity for existing RC structures", Computational Methods, Seismic Protection, Hybrid Testing and Resilience in Earthquake Engineering, Eds. G.P. Cimellaro et al., Geotechnical, Geological and Earthquake Engineering, 33, 287-306, Springer International Publishing Switzerland.
  21. De Stefano, M. and Pintucchi, B. (2008), "A review of research on seismic behavior of irregular building structures since 2002", Bul. Earthq. Eng., 6, 285-308. https://doi.org/10.1007/s10518-007-9052-3
  22. De Stefano, M. and Pintucchi, B. (2010), "Predicting torsion-induced lateral displacements for pushover analysis: Influence of torsional stiffness characteristics", Earthq. Eng. Struct. Dyn., 39, 1369-1394.
  23. EC 2 (2002), Eurocode 2: Design of concrete structures.
  24. EC 8-3 (2005), Design of structures for earthquake resistance, part 3: strengthening and repair of buildings, European standard EN 1998-3. European Committee for Standardization (CEN), Brussels.
  25. Fajfar, P. Marusic, D. and Perus, I. (2005), "Torsional effects in the pushover-based seismic analysis of buildings", J. Earthq. Eng., 9(6), 831-854. https://doi.org/10.1080/13632460509350568
  26. Fardis, M.N. (2009), Seismic design, assessment and retrofitting of concrete buildings: based on EN-Eurocode8. Springer, September.
  27. Franchin, P., Pinto, P.E. and Rajeev, P. (2007), "Confidence factor?", J. Earthq. Eng., 14(7), 989-1007. https://doi.org/10.1080/13632460903527948
  28. Franchin, P., Pinto, P.E. and Rajeev, P. (2009), "Confidence in the Confidence factor", Proceedings of Eurocode 8 Perspectives from the Italian Standpoint Workshop, Napoli, Italy.
  29. Jalayer, F., Iervolino, I. and Manfredi, G. (2008), "Structural modeling: uncertainties and their influence on seismic assessment of existing RC structures", Struct. Saf., 32(3), 220-228. https://doi.org/10.1016/j.strusafe.2010.02.004
  30. Magliulo, G., Maddolani, G. and Cosenza, E. (2012), "Extension of N2 method top plan irregular buildings considerino accidental eccentricita", Soil Dyn. Earthq. Eng., 43, 69-84. https://doi.org/10.1016/j.soildyn.2012.07.032
  31. Mander, J.B., Priestley, M.J.N. and Park, R. (1988), "Theoretical stress-strain model for confined concrete", J. Struct. Div., ASCE, 114, 1804-1826. https://doi.org/10.1061/(ASCE)0733-9445(1988)114:8(1804)
  32. Marano, G.C., Quaranta, G. and Mezzina, M. (2008), "Hybrid technique for partial safety factors calibration. Proc. Reluis2Rm08 "Valutazione e riduzione della vulnerabilita sismica di edifici esistenti in c.a.", Eds. E. Cosenza, G. Manfredi, G. Monti Eds., Polimetrica International Scientific Publisher, Roma.
  33. Masi, A. and Vona, M. (2009), "Estimation of the in-situ concrete strength: provisions of the European and Italian seismic codes and possible improvements provisions of the European and Italian seismic codes and possible improvements", Proceedings of Eurocode 8 Perspectives from the Italian Standpoint Workshop, Napoli, Italy.
  34. Masi, A., Vona, M. and Manfredi, V. (2008), "A parametric study on RC existing buildings to compare different analysis methods considered in the European seismic code (EC8-3)", Proceedings of the 14th WCEE, Beijing, China.
  35. Monti, G., Alessandri, S. and Goretti, A. (2007), "Livelli di conoscenza e fattori di confidenza. XII Convegno ANIDIS", L'ingegneria sismica in Italia, Pisa, Giugno.
  36. Myslimaj, B. and Tso, W.K. (2005), "A design-oriented approach to strength distribution in single story asymmetric systems with elements having strength-dependent stiffness", Earthq. Spectra, 21, 197-212. https://doi.org/10.1193/1.1854152
  37. NTC 2008. Norme tecniche per le costruzioni. D.M. Ministero Infrastrutture e Trasporti 14 gennaio, G.U.R.I. 4 Febbraio, Roma.
  38. Perus, I. and Fajfar, P. (2005), "On the inelastic torsional response of single-story structures under bi-axial excitation", Earthq. Eng. Struct, Dyn., 34, 931-941. https://doi.org/10.1002/eqe.462
  39. Rajeev, P., Franchin, P., and Pinto, P. E. (2010), "Review of confidence factor in EC8-Part 3: A European code for seismic assessment of existing buildings", International Conference on Sustainable Built Environment ICSBE 2010, Kandy, Sri Lanka.
  40. Seismosoft (2006), Seismostruct Version 5.2.2 - A computer program for static and dynamic nonlinear analysis of framed structures. Available online from URL: www.seismosoft.com.
  41. Sommer, A. and Bachmann, H. (2005), "Seismic behavior of asymmetric RC wall buildings: principles and new deformation-based design methods", Earthq. Eng. Struct. Dyn., 34, 101-124. https://doi.org/10.1002/eqe.412
  42. Shakeri, K., Tarbali, K. and Mohhebi, M. (2012), "An adaptive modal pushover procedure for asymmetric-plan buildings", Eng. Struct., 36, 160-172. https://doi.org/10.1016/j.engstruct.2011.11.032
  43. Tso, W.K. and Myslimaj, B. (2003), "A yield displacement distribution-based approach for strength assignment to lateral force-resisting elements having strength dependent stiffness", Earthq. Eng. Struct. Dyn., 32, 2319-2351. https://doi.org/10.1002/eqe.328

피인용 문헌

  1. Combined effects of axial load and concrete strength variation on the seismic performance of existing RC buildings vol.14, pp.3, 2016, https://doi.org/10.1007/s10518-015-9858-3
  2. Seismic assessment of a real RC asymmetric hospital building according to NTC 2008 analysis methods vol.13, pp.10, 2015, https://doi.org/10.1007/s10518-015-9758-6
  3. Sensitivity study on the discretionary numerical model assumptions in the seismic assessment of existing buildings vol.98, 2017, https://doi.org/10.1016/j.soildyn.2017.04.001
  4. Experimental assessment of concrete compressive strength in old existing RC buildings: A possible way to reduce the dispersion of DT results vol.8, 2016, https://doi.org/10.1016/j.jobe.2016.10.008
  5. Seismic performance sensitivity to concrete strength variability: a case-study vol.9, pp.2, 2015, https://doi.org/10.12989/eas.2015.9.2.321
  6. New predictive models to evaluate concrete compressive strength using the SonReb method vol.27, pp.None, 2015, https://doi.org/10.1016/j.jobe.2019.100962
  7. Nano-materials on the strength of ultra-high performance concrete vol.578, pp.1, 2015, https://doi.org/10.1080/00150193.2021.1902780
  8. Torsional sensitivity criteria in seismic codes vol.21, pp.1, 2015, https://doi.org/10.12989/eas.2021.21.1.001
  9. Concrete Compressive Strength by Means of Ultrasonic Pulse Velocity and Moduli of Elasticity vol.14, pp.22, 2015, https://doi.org/10.3390/ma14227018