The Role of Mass Eccentricity on the Earthquake Induced Torsion in Buildings

  • Authors

    • George K. Georgoussis
    • Anna Mamou
    2018-08-26
    https://doi.org/10.14419/ijet.v7i3.32.18386
  • Earthquake engineering, Mass eccentricity, Modal analysis, Optimum torsion axis
  • Abstract

    This paper investigates the effect of mass eccentricity on the earthquake induced torsion in buildings. An analytical solution is proposed, which identifies the location of a key structural element for which the torsional response of a structure is minimized for any height wise variation of the mass eccentricities. The accuracy of the analytical solution is then verified with parametric numerical modelling on 9-story buildings with height wise variations of the accidental eccentricities. The numerical modeling results show that the top rotations and base torques have an inverted peak, which indicates an optimum location of the key structural element, for which the torsional response of the structure is minimized. The location of the key element which minimizes the torsional response of the structure predicted by the analytical solution is verified with reasonable accuracy by the numerical modeling results. 

           

     

  • References

    1. [1] Kan, C.L., Chopra, A.K. (1977). Effects of torsional coupling on earthquake forces in buildings. J. Struct. Div. ASCE 103, No. 4, 805-819.

      [2] Tso, W.K., Dempsey, K.M. (1980). Seismic torsional provision for dynamic eccentricity. Earthquake Eng Struct Dyn. 8, No. 3, 275-289.

      [3] Dempsey, K.M., Irvine, H.M. (1979). Envelopes of maximum seismic response for a partially symmetric single-storey- building model. Earthquake Eng. Struct. Dyn. 7, No. 2, 161-180.

      [4] Chandler, A.M., Hutchinson, G.L. (1986). Torsional coupling effects in the earthquake response of asymmetric building. Eng. Struct. 8, No. 4, 222-236.

      [5] Jennings, P.C., Kuroiwa, J.H. (1968). Vibration and soil structure interaction tests of a nine-storey reinforced concrete building, Bull. Seism. Soc. Am. 58, No. 3, 891-916.

      [6] Naeim F, Lew M. The (2000). 1999 earthquake disasters worldwide: how many times do we have to reâ€learn the fundamentals of seismic engineering? The Structural Design of Tall Buildings 9, No. 2, 161–182.

      [7] CEN. EN 1998-1 (2004). EuroCode 8: design of structures for earthquake resistance—part 1: general rules, seismic actions and rules for buildings. European Committee for Standardization, Bruxelles

      [8] ASCE/SEI 7-10, Minimum Design Loads and Associated Criteria for Buildings and Other Structures, Committee on Minimum Design Loads for Buildings and Other Structures of the Codes and Standards Activities Division of the Structural Engineering Institute of ASCE

      [9] EAK-2000. Greek Aseismic Code (2000) Greek Ministry of Environment, City Planning and Public Works. Greece.

      [10] Cheung, VW.T., Tso, W.K. (1986). Eccentricity in irregular multi-story building, Can. J. Civ. Eng 13, No. 1, 46-52.

      [11] Makarios, T., Anastassiadis, K. (1998a). Real and fictitious elastic axis of multi-storey buildings applications. Struct. Design Tall Build. 7, No. 1, 33-45.

      [12] Makarios, T., Anastassiadis, K., (1998b). Real and Fictitious Elastic axis of Multi-Storey Buildings Applications. Struct. Design Tall Build. 7, No. 1, 57-71.

      [13] Marino, E.M., Rossi, P.P. (2004). Exact evaluation of the Location of the Optimum Torsion Axis. Struct. Design Tall Spec. Build. 13, No. 4, 277-290.

      [14] Basu, D., Jain, S.K. (2007). Alternative Method to Locate Center of Rigidity in Asymmetric Buildings. Earthquake Engng. Struct. Dyn. 36, No. 7, 965-973.

      [15] Georgoussis, G.K. (2016). An approach for minimum rotational response of medium-rise asymmetric structures under seismic excitations. Advances in Structural Engineering 19, No. 3, 420-436.

      [16] Georgoussis, G.K. (2010). Modal Rigidity Center: its use for assessing elastic torsion in asymmetric buildings. Earthquakes and Structures 1, No. 2, 163-175.

      [17] Georgoussis, G.K. (2014). Modified seismic analysis of multistory asymmetric elastic buildings and suggestions for minimizing the rotational response. Earthquakes and Structures 7, No. 1, 39-52.

      [18] Georgoussis, G.K. (2015). Minimizing the torsional response of inelastic multistory buildings with simple eccentricity. Canadian J. Civil Engng 42, No. 11, 966-969.

      [19] Georgoussis, G.K. (2017). Locating optimum torsion axis in asymmetric buildings subjected to seismic excitation. Proceedings of the Institution of Civil Engineers - Structures and Buildings, Ahead of Print, https://doi.org/10.1680/jstbu.17.00068

      [20] Georgoussis, G.K., Mamou, A. (2018). The effect of mass eccentricity on the torsional response of building structures, under review by Structural Engineering and Mechanics, An International Journal

      [21] Newmark, N.M., Rosenblueth, E. (1971). Fundamentals of Earthquake Engineering, Prentice Hall N.J.

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  • How to Cite

    K. Georgoussis, G., & Mamou, A. (2018). The Role of Mass Eccentricity on the Earthquake Induced Torsion in Buildings. International Journal of Engineering & Technology, 7(3.32), 29-34. https://doi.org/10.14419/ijet.v7i3.32.18386

    Received date: 2018-08-28

    Accepted date: 2018-08-28

    Published date: 2018-08-26