DOI QR코드

DOI QR Code

Fundamental periods of reinforced concrete building frames resting on sloping ground

  • De, Mithu (Department of Civil Engineering, Indian Institute of Engineering Science and Technology) ;
  • Sengupta, Piyali (Department of Civil Engineering, Indian Institute of Technology (ISM)) ;
  • Chakraborty, Subrata (Department of Civil Engineering, Indian Institute of Engineering Science and Technology)
  • Received : 2017.11.02
  • Accepted : 2018.02.21
  • Published : 2018.04.25

Abstract

Significant research efforts were undertaken to evaluate seismic performance of vertically irregular buildings on flat ground. However, there is scarcity of study on seismic performance of buildings on hill slopes. The present study attempts to investigate seismic behaviour of reinforced concrete irregular stepback building frames with different configurations on sloping ground. Based on extensive regression study of free vibration results of four hundred seventeen frames with varying ground slope, number of story and span number, a modification is proposed to the code based empirical fundamental time period estimation formula. The modification to the fundamental time period estimation formula is a simplified function of ground slope and a newly introduced equivalent height parameter to reflect the effect of stiffness and mass irregularity. The derived empirical formula is successfully validated with various combinations of slope and framing configurations of buildings. The correlation between the predicted and the actual time period obtained from the free vibration analysis results are in good agreement. The various statistical parameters e.g., the root mean square error, coefficient of determination, standard average error generally used for validation of such regression equations also ensure the prediction capability of the proposed empirical relation with reasonable accuracy.

Keywords

References

  1. Aranda, G.R. (1984), "Ductility demands for R/C frames irregular in elevation", Proceedings of the 8th World Conference on Earthquakes and Engineering, San Francisco.
  2. ASCE 7 (2005), Minimum Design Loads for Building and Other Structures (ASCE/SEI 7-05), American Society of Civil Eng., New York, U.S.A.
  3. Asteris, P.G., Constantinos, C.R., Filippos, F., Alkis, F. and Athanasios, K.T. (2017), "Fundamental period of infilled RC frame structures with vertical irregularity", Struct. Eng. Mech., 61(5), 663-674. https://doi.org/10.12989/sem.2017.61.5.663
  4. Asteris, P.G., Repapis, C., Repapi, E. and Cavaleri, L. (2016), "Fundamental period of infilled reinforced concrete frame structures", Struct. Infrastr. E., 13(7), 1-13.
  5. Asteris, P.G., Repapis, C., Tsaris, A.K., Di Trapani, F. and Cavaleri, L. (2015a), "Parameters affecting the fundamental period of infilled RC frame structures", Earthq. Struct., 9(5), 999-1028. https://doi.org/10.12989/eas.2015.9.5.999
  6. Asteris, P.G., Repapis, C.C., Cavaleri, L., Sarhosis, V. and Athanasopoulou, A. (2015b), "On the fundamental period of infilled RC frame buildings", Struct. Eng. Mech., 54(6), 1175-1200. https://doi.org/10.12989/sem.2015.54.6.1175
  7. Birajdar, B.G. and Nalawade, S.S. (2004), "Seismic analysis of building resting on sloping ground", Proceedings of the 13th World Conference on Earthquakes and Engineering, Vancouver, B.C., Canada, August.
  8. Chopra, A.K. and Goel, R.K. (2000), "Building period formulas for estimating seismic displacements", Earthq. Spectra, 16(2), 533-536. https://doi.org/10.1193/1.1586125
  9. Detlof, V.W., Nels, R. and Kitsuse, A. (2003), "Framing earthquake retrofitting decisions: The case of hillside homes in Loss Angeles", PEER Report 2000/03, Pacific Earthquake Engineering Research Center, University of California, Berkeley.
  10. Eurocode 8 (2004), Design of Structures for Earthquake Resistance, EN 1998-1.
  11. Georgoussisa, G., Tsompanosa, A. and Triantafyllos, M. (2015), "Approximate seismic analysis of multi-story buildings with mass and stiffness irregularities", Procedia Eng., 125, 959-966. https://doi.org/10.1016/j.proeng.2015.11.147
  12. Goel, R.K. and Chopra, A.K. (1997), "Period formulas for moment resisting frame buildings", J. Struct. Eng., ASCE, 123(11), 1454-1461. https://doi.org/10.1061/(ASCE)0733-9445(1997)123:11(1454)
  13. Hatzigeorgiou, G.D. and Kanapitsas, G. (2013), "Evaluation of fundamental period of low-rise and mid-rise reinforced concrete buildings", Earthq. Eng. Struct. Dyn., 42(11), 1599-1616. https://doi.org/10.1002/eqe.2289
  14. Hideo, T., Fumiya, I. and Motohiro, M. (2011), "A simplified analysis of super building structures with setback", Earthq. Struct., 2(1), 43-64. https://doi.org/10.12989/eas.2011.2.1.043
  15. Humar, J.L. and Wright, E.W. (1977), "Earthquake response of steel framed multi-storey buildings with set-backs", Earthq. Eng. Struct. Dyn., 5(1), 15-39. https://doi.org/10.1002/eqe.4290050103
  16. IS 1893 (Part 1) (2016), BIS: Indian Standard Criteria for Earthquake Resistant Design of Structures, Part 1 - General Provisions and Buildings (Fifth Revision), Bureau of Indian Standards, New Delhi.
  17. Karavasilis, T.L, Bazeos, N. and Beskos, D.E. (2008b), "Seismic response of plane steel MRF with setbacks: Estimation of inelastic deformation demands", J. Constr. Steel Res., 64, 644-654.
  18. Karavasilis, T.L., Bazeos, N. and Beskos, D.E. (2008a), "Estimation of seismic inelastic deformation demands in plane steel MRF with vertical mass irregularities", Eng. Struct., 30(11), 3265-3275. https://doi.org/10.1016/j.engstruct.2008.05.005
  19. Kenji, F. (2016), "Assessment of pushover-based method to a building with bidirectional setback", Earthq. Struct., 11(3), 421-443. https://doi.org/10.12989/eas.2016.11.3.421
  20. Khoure, W., Rutenberg, A. and Levy, R. (2005), "The seismic response of asymmetric setback perimeter-frame structures", Proceedings of the 4th European Workshop on the Seismic Behaviour of Irregular and Complex Structures, Thessaloniki, August.
  21. Kumar, S. and Paul, D.K. (1998), "A simplified method for elastic seismic analysis of hill buildings", J. Earthq. Eng., 2(2), 241-266. https://doi.org/10.1080/13632469809350321
  22. Kumar, S. and Paul, D.K. (1999), "Hill buildings configuration from seismic consideration", J. Struct. Eng., ASCE, 26(3), 179-185.
  23. Moehle, J.P. and Alarcon, L.F. (1986), "Seismic Analysis Methods for Irregular Buildings", J. Struct. Eng., ASCE, 112(1), 35-52. https://doi.org/10.1061/(ASCE)0733-9445(1986)112:1(35)
  24. Panagiotis, G.A., Constantinos, C.R., Filippos, F., Fotos, A. and Tsaris, A.K. (2017), "Fundamental period of infilled RC frame structures with vertical irregularity", Struct. Eng. Mech., 61(5), 663-674. https://doi.org/10.12989/sem.2017.61.5.663
  25. SAP2000 (2016), Integrated Software for Structural Analysis and Design of Structures, Computers and Structures Inc., Berkeley, CA.
  26. Sarkar, P., Prasad, M. and Menon, D. (2010), "Vertical geometric irregularity in stepped building frames", Eng. Struct., 32, 2175-2182. https://doi.org/10.1016/j.engstruct.2010.03.020
  27. Sarkar, P., Prasad, M. and Menon, D. (2016), "Seismic evaluation of RC stepped building frames using improved pushover analysis", Earthq. Struct., 10(4), 913-938. https://doi.org/10.12989/eas.2016.10.4.913
  28. Singh, Y. and Phani, G. (2012), "Seismic behaviour of buildings located on slopes-An analytical study and some observations from sikkim earthquake of September, 2011", Proceedings of the 15th World Conference on Earthquakes and Engineering. Lisbon.
  29. Surana, M., Singh, Y. and Lang, D.H. (2015), "Seismic fragility analysis of hill-buildings in Indian Himalayas", SECED Conference: Earthquake Risk and Engineering towards a Resilient World, Cambridge, July.
  30. Varadharajan, S., Sehgal, V.K. and Saini, B. (2014), "Seismic response of multistory reinforced concrete frame with vertical mass and stiffness irregularities", Struct. Des. Tall Spec. Build., 23(5), 362-389. https://doi.org/10.1002/tal.1045
  31. Vijayanarayanan, A.R., Goswami, R. and Murty, C.V.R. (2012), "Performance of RC buildings along hill slopes of Himalayas during 2011 sikkim earthquake", Proceedings of the 15th World Conference on Earthquakes and Engineering, Lisbon.
  32. Vijayanarayanan, A.R., Goswami, R. and Murty, C.V.R. (2017), "Identifying stiffness irregularity in buildings using fundamental lateral mode shape", Earthq. Struct., 12(4), 434-448.