Earthquakes and Structures

Techno-Press (테크노프레스)
권호 표지
DOI QR코드

DOI QR Code

Modification of Chinese-code formula for equivalent lateral force method

  • Wang, Mingzhen (College of Aerospace and Civil Engineering, Harbin Engineering University) ;
  • Yang, Zailin (College of Aerospace and Civil Engineering, Harbin Engineering University) ;
  • Gao, Lin (College of Civil Engineering, Chongqing University of Arts and Sciences)
  • Received : 2020.10.28
  • Accepted : 2021.05.21
  • Published : 2021.08.25
⟨ Previous Next ⟩

Abstract

The equivalent lateral force method is one of the commonly used methods for the seismic design of building structures. The assumptions included an equivalent coefficient of 0.85 when determining the equivalent total weight of the structure, and the horizontal seismic action distributed as an inverted triangle pattern is used in the existing formula in relevant Chinese codes. And the two assumptions make a big difference between the calculation results of the equivalent lateral force method and the mode-superposition response spectrum method in Chinese code. The dynamic structural parameters of the designed six reinforced concrete frame structures and the calculated case structure, which were designed according to Chinese codes, are extracted in this paper. The six structures are analyzed using the mode-superposition response spectrum method and the equivalent lateral force method in Chinese code, respectively. The comparative analysis results show that shear forces at the bottom of structures calculated by the equivalent lateral force method in Chinese code is smaller, but the horizontal displacement of each storey of the structure is larger. Aiming at the shortcomings of the equivalent lateral force method in Chinese codes, combining with the calculation results of the mode-superposition response spectrum method, a modified calculation formula of the equivalent lateral force method is proposed. The calculation results of the modified equivalent lateral force method established in this paper are superior to the calculation results of the equivalent lateral force method in Chinese codes through examples verifications.

Keywords

Acknowledgement

This research described in this paper was financially supported by the Natural Science Foundation of Chongqing, China, grant number cstc2019jcyj-msxmX0739 and Scientific Research Fund of Institute of Engineering Mechanics, China Earthquake Administration, grant number 2019D13.

References

  1. ATC-40 (1996), Seismic Evaluation and Retrofit of Reinforced Concrete Buildings. Applied Technology Council, California, U.S.A.
  2. Caglar, N., Pala, M., Elmas, M. and Eryilmaz, D.M. (2009), "A new approach to determine the base shear of steel frame structures", J. Construct. Steel Res., 65(1), 188-195. https://doi.org/10.1016/j.jcsr.2008.07.012.
  3. Chopra, A.K. (2007), "Elastic response spectrum: a historical note", Earthq. Eng. Struct. Dyn., 36(1), 3-12. https://doi.org/10.1002/eqe.609.
  4. GB 50003-2011 (2011), Code for Design of Masonry Structures, Ministry of Housing and Urban-Rural Development of the People's Republic of China; Beijing, China.
  5. GB 50010-2010 (2015), Code for Design of Concrete Structures, Ministry of Housing and Urban-Rural Development of the People's Republic of China; Beijing, China.
  6. GB50011-2010 (2016), Code for Seismic Design of Building, Ministry of Housing and Urban-Rural Development of the People's Republic of China; Beijing, China.
  7. Habibi, A., Vahed, M. and Asadi, K. (2018), "Evaluation of seismic performance of RC setback frames", Struct. Eng. Mech., 66(5), 609-619. https://doi.org/10.1080/13632460701758539.
  8. Hajirasouliha, I. and Moghaddam, H. (2009), "New lateral force distribution for seismic design of structures", J. Struct. Eng., 135(8), 906-915. https://doi.org/10.1061/(ASCE)0733-9445(2009)135:8(906).
  9. Hsiao, J.K. (2006), "Equivalent lateral force procedure for the seismic story drift design of tall frames using a hand-calculated approach", Struct. Des. Tall Spec. Build., 15(2), 197-219. https://doi.org/10.1002/tal.291.
  10. JGJ-3-2010 (2011), Technical Specification for Concrete Structures of Tall Building, Ministry of Housing and Urban-Rural Development of the People's Republic of China; Beijing, China.
  11. Khose, V.N., Singh, Y. and Lang D.H. (2012), "A comparative study of design base shear for RC buildings in selected seismic design codes", Earthq. Spectra, 28(3), 1047-1070. https://doi.org/10.1193/1.4000057
  12. Kumar, N. (2018), "Earthquake resistant design & comparison of (G+7) OMRF building at meerut by using equivalent lateral force & response spectrum method", Int. J. Res. Appl. Sci. Eng. Technol., 6(7), 456-462. https://doi.org/10.22214/ijraset.2018.7065.
  13. Nagender, T., Parulekar, Y.M. and Rao, G.A. (2019), "Performance evaluation and hysteretic modeling of low rise reinforced concrete shear walls", Earthq. Struct., 16(1), 41-54. http://dx.doi.org/10.12989/eas.2019.16.1.041
  14. O'Reilly, G.J. and Calvi, G.M. (2019), "Conceptual seismic design in performance-based earthquake engineering", Earthq. Eng. Struct. Dyn., 48(4), 389-411. http://dx.doi.org/10.1002/eqe.3141.
  15. O'Reilly, G.J. and Calvi, G.M. (2020), "Quantifying seismic risk in structures via simplified demand-intensity models", Bull. Earthq. Eng., 18(5), 2003-2022. http://dx.doi.org/10.1007/s10518-019-00776-0.
  16. Rahgozar, N. and Rahgozar, N. (2021, April), "Proposal of lateral forces for capacity design of controlled rocking steel cores considering higher mode effects", Struct., 30, 1086-1096. https://doi.org/10.1016/J.ISTRUC.2021.01.072
  17. Roy, R. and Mahato, S. (2013), "Equivalent lateral force method for buildings with setback: adequacy in elastic range", Earthq. Struct., 4(6), 685-710. https://doi.org/10.12989/eas.2013.4.6.685.
  18. Shahnazaryan, D. and O'Reilly, G.J. (2021), "Integrating expected loss and collapse risk in performance-based seismic design of structures", Bull. Earthq. Eng., 19(2), 987-1025. https://doi.org/10.1007/S10518-020-01003-X.
  19. Shrestha, S. (2019), A Comparative Study of Equivalent Lateral Force Method and Response Spectrum Analysis in Seismic Design of Structural Frames, Master Theis, Southern Illinois University at Carbondale, Nepal.
  20. Touqan, A.R. and Helou, S.H. (2008), "A scrutiny of the equivalent static lateral load method of design for multistory masonry structures", 2008 Seismic Engineering Conference Commemorating the 1908 Messina and Reggio Calabria Earthquake, Reggio Calabria, Italy, July