Structural Engineering and Mechanics

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Seismic response modification factors for stiffness degrading soil-structure systems

  • Ganjavi, Behnoud (Department of Civil Engineering, University of Mazandaran) ;
  • Bararnia, Majid (Department of Civil, Water & Environmental Engineering, Shahid Beheshti University) ;
  • Hajirasouliha, Iman (Department of Civil and Structural Engineering, University of Sheffield)
  • Received : 2018.05.06
  • Accepted : 2018.06.25
  • Published : 2018.10.25
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Abstract

This paper aims to develop response modification factors for stiffness degrading structures by incorporating soil-structure interaction effects. A comprehensive parametric study is conducted to investigate the effects of key SSI parameters, natural period of vibration, ductility demand and hysteretic behavior on the response modification factor of soil-structure systems. The nonlinear dynamic response of 6300 soil-structure systems are studied under two ensembles of accelograms including 20 recorded and 7 synthetic ground motions. It is concluded that neglecting the stiffness degradation of structures can results in up to 22% underestimation of inelastic strength demands in soil-structure systems, leading to an unexpected high level of ductility demand in the structures located on soft soil. Nonlinear regression analyses are then performed to derive a simplified expression for estimating ductility-dependent response modification factors for stiffness degrading soil-structure systems. The adequacy of the proposed expression is investigated through sensitivity analyses on nonlinear soil-structure systems under seven synthetic spectrum compatible earthquake ground motions. A good agreement is observed between the results of the predicted and the target ductility demands, demonstrating the adequacy of the expression proposed in this study to estimate the inelastic demands of SSI systems with stiffness degrading structures. It is observed that the maximum differences between the target and average target ductility demands was 15%, which is considered acceptable for practical design purposes.

Keywords

References

  1. ASCE 7-16 (2010), Minimum Design Loads for Buildings and Other Structures, American Society of Civil Engineers, Reston, U.S.A.
  2. Aviles J.a Perez-Rocha, L.E.B. (2005), "Influence of foundation flexibility on $R{\mu}$ and C ${\mu}$ factors", J. Struct. Eng., 131(2), 221-230. https://doi.org/10.1061/(ASCE)0733-9445(2005)131:2(221)
  3. Bararnia, M., Hassani, N., Ganjavi, B. and Amiri, G.G. (2018), "Estimation of inelastic displacement ratios for soil-structure systems with embedded foundation considering kinematic and inertial interaction effects", Eng. Struct., 159, 252-264. https://doi.org/10.1016/j.engstruct.2018.01.002
  4. Computers and Structures, I (2006), PERFORM-3D: Nonlinear Analysis and Performance Assessment for 3-D Structures: Version 4, Computers and Structures, Inc., Berkeley, Californiam U.S.A.
  5. Elghadamsi, F. and Mohraz, B. (1987), "Inelastic earthquake spectra", Earthq. Eng. Struct. Dyn., 15(1), 91-104. https://doi.org/10.1002/eqe.4290150107
  6. Erberik, M.A. (2011), "Importance of degrading behavior for seismic performance evaluation of simple structural systems", J. Earthq. Eng., 15(1), 32-49. https://doi.org/10.1080/13632461003642421
  7. Eser, M., Aydemir, C. and Ekiz, L. (2012), "Soil structure interaction effects on strength reduction factors", Struct. Eng. Mech., 41(3), 365-378. https://doi.org/10.12989/sem.2012.41.3.365
  8. FEMA 440 (2005), Improvement of Nonlinear Static Seismic Analysis Procedures, Federal Emergency Management Agency, Washington, U.S.A.
  9. FEMA P-1050 (2015), NEHRP Recommended Seismic Provisions for New Buildings and Other Structures, Federal Emergency Management Agency, Washington, U.S.A.
  10. Fischinger, M., Fajfar, P. and Vidic, T. (1994), "Factors contributing to the response reduction", Proceedings of the 5th U.S. National Conference on Earthquake Engineering, Chicago, Illinois, U.S.A.
  11. Ganjavi, B. and Hao, H. (2012), "A parametric study on the evaluation of ductility demand distribution in multi-degree-of-freedom systems considering soil-structure interaction effects", Eng. Struct., 43, 88-104. https://doi.org/10.1016/j.engstruct.2012.05.006
  12. Ghannad, M. and Jahankhah, H. (2007), "Site-dependent strength reduction factors for soil-structure systems", Soil Dyn. Earthq. Eng., 27(2), 99-110. https://doi.org/10.1016/j.soildyn.2006.06.002
  13. Gioncu, V. and Mazzolani, F. (2010), Earthquake Engineering for Structural Design, CRC Press.
  14. Hassani, N., Bararnia, M. and Amiri, G.G. (2018), "Effect of soilstructure interaction on inelastic displacement ratios of degrading structures", Soil Dyn. Earthq. Eng., 104, 75-87. https://doi.org/10.1016/j.soildyn.2017.10.004
  15. Housner, G. and Jennings, P.C. (1964), "Generation of artificial earthquakes", J. Eng. Mech. Div., 90(1), 113-152.
  16. Karmakar, D. and Gupta, V.K. (2007), "Estimation of strength reduction factors via normalized pseudo-acceleration response spectrum", Earthq. Eng. Struct. Dyn., 36(6), 751-763. https://doi.org/10.1002/eqe.651
  17. Lu, Y., Hajirasouliha, I. and Marshall, A.M. (2016), "Performance-based seismic design of flexible-base multi-storey buildings considering soil-structure interaction", Eng. Struct., 108, 90-103. https://doi.org/10.1016/j.engstruct.2015.11.031
  18. MATLAB (2014), MATLAB: The Language of Technical Computing, The Mathworks Inc, Nattick, MA.
  19. Miranda, E. (1993), "Site-dependent strength-reduction factors", J. Struct. Eng., 119(12), 3503-3519. https://doi.org/10.1061/(ASCE)0733-9445(1993)119:12(3503)
  20. Miranda, E. and Bertero, V.V. (1994), "Evaluation of strength reduction factors for earthquake-resistant design", Earthq. Spectr., 10(2), 357-379. https://doi.org/10.1193/1.1585778
  21. Miranda, E. and Ruiz-Garcia, J. (2002), "Influence of stiffness degradation on strength demands of structures built on soft soil sites", Eng. Struct., 24(10), 1271-1281. https://doi.org/10.1016/S0141-0296(02)00052-4
  22. Nakhaei, M. (2004), "The effect of soil-structure interaction on damage index of buildings", M.Sc. Dissertation, Sharif University of Technology, Tehran, Iran.
  23. Nassar, A.A. and Krawinkler, H. (1991), Seismic Demands for SDOF and MDOF Systems, Report No. 95, The John A. Blume Earthquake Engineering Center.
  24. Newmark, N.M. and Hall, W.J. (1969). "Seismic design criteria for nuclear reactor facilities", Proceedings of the 4th World conference on Earthquake Engineering.
  25. Ordaz, M. and Perez-Rocha, L. (1998), "Estimation of strengthreduction factors for elastoplastic systems: a new approach", Earthq. Eng. Struct. Dyn., 27(9), 889-902. https://doi.org/10.1002/(SICI)1096-9845(199809)27:9<889::AID-EQE755>3.0.CO;2-W
  26. Prakash, V. and Powell, G. (1993), DRAIN-2DX, Version 1.02, User Guide, University of California, Berkeley, U.S.A.
  27. Rahnama, M. and Krawinkler, H. (1993), Effects of Soft Soil and Hysteresis Model on Seismic Demnds, Report No. 108, The John A. Blume Earthquake Engineering Center.
  28. Rezaeian, S. and Kiureghian, A.D. (2010), Stochastic Modeling and Simulation of Ground Motions for Performance-Based Earthquake Engineering, Report No. Pacific Earthquake Engineering Research Center.
  29. Santa-Ana, P.R. and Miranda, E. (2000), "Strength reduction factors for multi-degree-of-freedom systems", Proceedings of the 12th world conference on Earthquake Engineering.
  30. SeismoArtif (2016), Earthquake Engineering Software Solutions, Seismosoft.
  31. Song, J.K. and Gavin, H.P. (2011), "Effect of hysteretic smoothness on inelastic response spectra with constantductility", Earthq. Eng. Struct. Dyn., 40(7), 771-788. https://doi.org/10.1002/eqe.1058
  32. Veletsos, A. and Newmark, N.M. (1960), "Effect of inelastic behavior on the response of simple systems to earthquake motions", Proceedings of the 2nd World Conference on Earthquake Engineering, Japan.
  33. Willmott, C.J., Robeson, S.M. and Matsuura, K. (2012), "A refined index of model performance", Int. J. Climatol., 32(13), 2088-2094. https://doi.org/10.1002/joc.2419
  34. Wolf, J.P. (1994), Foundation Vibration Analysis using Simple Physical Models, Prentice-Hall, Englewood Cliffs, New Jersey, U.S.A.