Earthquakes and Structures

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Inelastic behavior of systems with flexible base

  • Fernandez-Sola, Luciano R. (Departamento de Materiales, Universidad Autonoma Metropolitana-Azcapotzalco) ;
  • Huerta-E catl, Juan E. (Departamento de Materiales, Universidad Autonoma Metropolitana-Azcapotzalco)
  • Received : 2017.02.28
  • Accepted : 2018.03.15
  • Published : 2018.05.25
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Abstract

This study explores the inelastic behavior of systems with flexible base. The use of a single degree of freedom system (ESDOF) with equivalent ductility to represent the response of flexible base systems is discussed. Two different equations to compute equivalent ductility are proposed, one which includes the contribution of rigid body components, and other based on the overstrength of the structure. In order to asses the accuracy of ESDOF approach with the proposed equations, the behavior of a 10-story regular building with reinforced concrete (RC) moment resisting frames is studied. Local and global ductility capacity and demands are used to study the modifications introduced by base flexibility. Three soil types are considered with shear wave velocities of 70, 100 and 250 m/s. Soil-foundation stiffness is included with a set of springs on the base (impedance functions). Capacity curves of the building are computed with pushover analysis. In addition, non linear time history analysis are used to asses the ductility demands. Results show that ductility capacity of the soil-structure system including rigid body components is reduced. Base flexibility does not modify neither yield and maximum base shear. Equivalent ductility estimated with the proposed equations is fits better the results of the numerical model than the one considering elastoplastic behavior. Modification of beams ductility demand due to base flexibility are not constant within the structure. Some elements experience reduced ductility demands while other elements experience increments when flexible base is considered. Soil structure interaction produces changes in the relation between yield strength reduction factor and structure ductility demand. These changes are dependent on the spectral shape and the period of the system with fixed and flexible base.

Keywords

References

  1. ASCE 7 (2010), Minimum Design Loads for Buildings and Other Structures, ASCE Standard ASCE/SEI 7-10, American Society of Civil Engineers.
  2. Aviles, J. (1991), "Respuesta sismica de un sistema sueloestructura", Revista Internacional de Metodos Numericos para Calculo y Diseno en Ingenieria, 7(1), 29-43. (in Spanish)
  3. Aviles, J. and Perez-Rocha, L.E. (2005), "Soil-structure interaction in yielding systems", Earthq. Eng. Struct. Dyn., 32(11), 1749-1771. https://doi.org/10.1002/eqe.300
  4. Aviles, J. and Perez-Rocha, L.E. (2011), "Bases para las nuevas disposisciones reglamentarias sobre la interaccion dinamica suelo estructura", Revista de Ingenieria Sismica, 71, 1-36. (in Spanish)
  5. Aviles, J. and Perez-Rocha, L.E. (2011), "Use of global ductility for design of structure-foundation systems", Soil Dyn. Earthq. Eng., 31, 1018-1026. https://doi.org/10.1016/j.soildyn.2011.03.008
  6. Aydemir, M.E. and Ekiz, I. (2013), "Soil-structure interaction effects on seismic behaviour of multistorey structures", Eur. J. Environ. Civil Eng., 17(8), 635-653. https://doi.org/10.1080/19648189.2013.810177
  7. Barcena, A. and Esteva, L. (2007), "Influence of dynamic soilstructure interaction on the nonlinear response and seismic reliability of multistorey systems", Earthq. Eng. Struct. Dyn., 36(3), 327-346. https://doi.org/10.1002/eqe.633
  8. Chopra, A.K. (2012), Dynamics of Structures, 4th Edition, Prentice Hall, New Jersey.
  9. Eser, M., Aydemir, C. and Ekiz, I. (2011) "Effects of soil-structure interaction on strength reduction factors", Procedia Eng., 14, 1696-1704. https://doi.org/10.1016/j.proeng.2011.07.213
  10. Fernandez-Sola, L.R. and Aviles, J. (2008) "Efectos de interaccion suelo-estructura en edificios con planta baja blanda", Revista de Ingenieria Sismica, 79, 71-90. (in Spanish)
  11. Fernandez-Sola, L.R. and Martinez-Galindo, G. (2015), "Behavior of RC frames with hysteretic dampers considering dynamic soil structure interaction", 11th Canadian Conference on Earthquake Engineering, Victoria, BC, Canada.
  12. Fernandez-Sola, L.R., Davalos-Chavez, D. and Tapia-Hernandez, E. (2014) "Influence of the dynamic soil structure interaction on the inelastic response of steel frames", 10th U.S. National Conference on Earthquake Engineering, Anchorage, Alaska.
  13. Fernandez-Sola, L.R., Tapia-Hernandez, E. and Davalos-Chavez, D. (2015), "Respuesta dinamica de marcos de acero con interaccion inercial suelo-estructura", Revista de Ingenieria Sismica, 92, 1-21. (in Spanish)
  14. Ganjavi, B. and Hao, H. (2011), "Elastic and inelastic response of single- and multi-degree-of-freedom systems considering soil structure interaction effects", Australian Earthquake Engineering Society 2011 Conference, Barossa Valley, South Australia.
  15. Gazetas, G. (1991), Foundation Vibrations, Foundation Engineering Handbook, Ed. H.Y. Fang, Van Nostrand Reinhold.
  16. Ghandil, M. and Behnamfar, F. (2017), "Ductility demands of MRF structures on soft soils considering soil-structure interaction", Soil Dyn. Earthq. Eng., 92, 203-214. https://doi.org/10.1016/j.soildyn.2016.09.051
  17. Ghannad, M.A. and Ahmadnia, A. (2006), "The effect of soilstructure interaction on inelastic structural demands", Eur. Earthq. Eng., 20(1), 23-35.
  18. Halabian, A.M. and Erfani, M. (2013), "The effect of foundation flexibility and structural strength on response reduction factor of RC frame structures", Struct. Des. Tall Spec. Build., 22(1), 1-28. https://doi.org/10.1002/tal.654
  19. Huerta-Ecatl, J.E. (2015), "Evaluacion de la interaccion dinamica suelo-estructura en el comportamiento inelastico de un edificio de concreto reforzado", Master Dissertation, Posgrado en Ingenieria Estructural, UAM-Azcapotzalco. (in Spanish)
  20. Jaimes-Tellez, M.A., Arredondo-Velez, C.A. and Fernandez-Sola, L.R. (2017), "Rocking of non-symmetric blocks in buildings considering effects associated with soil-structure interaction", J. Earthq. Eng., 1-28.
  21. Jarernprasert, S., Bazan-Zurita, E. and Bielak, J. (2013), "Seismic soil-structure interaction response of inelastic structures", Soil Dyn. Earthq. Eng., 47, 132-143. https://doi.org/10.1016/j.soildyn.2012.08.008
  22. Kausel, E., Whitman, R.V., Morray, J.P. and Elsabee, F. (1978), "The spring method for embedded foundations", Nucl. Eng. Des., 48, 377-392. https://doi.org/10.1016/0029-5493(78)90085-7
  23. MCBC (2004), "Reglamento de construcciones para el Distrito Federal", Gaceta Oficial del Departamento del Distrito Federal, Mexico, Mexico. (in Spanish)
  24. NBCC (2015), National Building Code of Canada, National Research Council of Canada, Ottawa.
  25. Novak, M., Sheta, M., El-Hifnawy, L., El-Marsafawi, H. and Ramadan, O. (2012), "DYNA6.1: A computer program for calculation of foundation response to dynamic loads", Geotechnical Research Centre, The University of Western Ontario, Canada.
  26. NZS 3101-1 (2006), New Zealand Standard Code of Practice for General Structural Design and Design Loadings for Buildings, Standards Association of New Zealand, Wellington.
  27. Park, R. and Paulay, T. (1974), Reinforced Concrete Structures, 1st Edition, John Wiley & Sons.
  28. Rosenblueth, E. and Resendiz, D. (1988), "Disposiciones reglamentarias de 1987 para tener en cuenta interaccion dinamica suelo-estructura", Series del Instituto de Ingenieria, 509, Universidad Nacional Autonoma de Mexico, Mexico. (in Spanish)
  29. Ruiz-Garcia, J. and Miranda, E. (2004), "Inelastic displacement ratios for design of structures on soft soil sites", J. Struct. Eng., ASCE, 130(12), 2051-2061. https://doi.org/10.1061/(ASCE)0733-9445(2004)130:12(2051)
  30. Takeda, T.M., Sozen, M.A. and Nielsen, N.N. (1970), "Reinforced concrete response to simulated earthquakes", J. Struct. Div., 96, 2557 - 2573.
  31. Wolf, J.P. (1985), Dynamic Soil-Structure Interaction, Prentice-Hall.
  32. Wolf, J.P. (1994), Foundation Vibration Analysis Using Simple Physical Models, Prentice-Hall.

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