Earthquakes and Structures

Techno-Press (테크노프레스)
권호 표지
DOI QR코드

DOI QR Code

Assessment of the effect of the soil deformability on the peak response of base-isolated buildings under seismic excitations

  • Christos Anastasiou (Department of Civil and Environmental Engineering, University of Cyprus) ;
  • Petros Komodromos (Department of Civil and Environmental Engineering, University of Cyprus)
  • Received : 2024.06.04
  • Accepted : 2024.09.27
  • Published : 2025.01.25
⟨ Previous Next ⟩

Abstract

This paper presents selected results from the numerical investigation of the potential effect of soil deformability on the peak seismic response of base-isolated buildings of various numbers of floors, under both near-fault and far-fault earthquake excitations. The dynamic simulations are conducted parametrically with the SAP2000 Open Application Programming Interface, through a custom-made software developed using the Python programming language. The motivation is twofold: firstly, to examine whether the common assumption that the soil deformability can be ignored in dynamic analyses of base-isolated buildings, assuming that it would be always beneficial to the peak seismic response; and, secondly, to assess the abilities of the provided interface in combination with a modern programming language to effectively and efficiently perform parametric analyses of base isolated buildings. Specifically, three different soil types are considered in the parametric analyses: rock, sand, and clay, using simplified soil springs to model the deformability of the supporting soil. Base isolated buildings with various numbers of stories are considered, while two sets of strong seismic excitations, near-fault and far-fault, are used in the conducted dynamic analyses, to assess the influence of soil deformability, as well as the earthquake characteristics, on the peak seismic responses of the simulated base isolated multi-story buildings. The computed results indicate that neglecting the soil deformability may lead to underestimation of the peak seismic responses, particularly in case of near-fault seismic excitations. That would be very crucial especially for the proper estimation of the required minimum width of the seismic gap that should be provided as clearance around a base isolated building to accommodate the maximum relative displacements that are expected at the seismic isolation level.

Keywords

References

  1. Aden, M.A., Al-Attar, A.A., Hejazi, F., Dalili, M. and Ostovar, N. (2019), "Effects of soil-structure interaction on base-isolated structures", IOP Conf. Ser.: Earth Environ. Sci., 357(1), 012031. https://doi.org/10.1088/1755-1315/357/1/012031.
  2. Baker, J.W. (2007), "Quantitative classification of near-fault ground motions using wavelet analysis", Bull. Seismol. Soc. Am., 97(5), 1486-1501. https://doi.org/10.1785/0120060255.
  3. Bowles, J.E. (1997), Foundation Analysis and Design, 5th Edition, McGraw-Hill, New York, NY, USA.
  4. Fjaer, E., Holt, R.M. and Horsrud, P. (2008), "Geological aspects of petroleum related rock mechanics", Develop. Petrol. Sci., 53, 103-133. https://doi.org/10.1016/S0376-7361(07)53003-7.
  5. Gazetas, G. (1991), "Formulas and charts for impedances of surface and embedded foundations", J. Geotech. Eng., 117(9), 1363-1381. https://doi.org/10.1061/(asce)0733-9410(1991)117:9(1363).
  6. Gazetas, G. and Dobry, R. (1984), "Horizontal response of piles in layered soils", J. Geotech. Eng., 110(1), 20-40. https://doi.org/10.1061/(ASCE)0733-9410(1984)110:1(20).
  7. Higashino, M. and Okamoto, S. (2006), Response Control and Seismic Isolation of Buildings, Routledge, London, UK.
  8. Jangid, R.S. and Kelly, J.M. (2001), "Base isolation for near-fault motions", Earthq. Eng. Struct. Dyn., 30(5), 691-707. https://doi.org/10.1002/eqe.31.
  9. Katsanos, E.I. and Sextos, A.G. (2013), "ISSARS: An integrated software environment for structure-specific earthquake ground motion selection", Adv. Eng. Softw., 58, 70-85. https://doi.org/10.1016/j.advengsoft.2013.01.003.
  10. Kavvadas, M. and Gazetas, G. (1993), "Kinematic seismic response and bending of free-head piles in layered soil", Géotech., 43(2), 207-222. https://doi.org/10.1680/geot.1993.43.2.207.
  11. Kelly, T.E. (2001), "Base isolation of structures: Design guidelines", Holmes Consulting Group Ltd., Wellington, New Zealand.
  12. Komodromos, P. (2000), Seismic Isolation for Earthquake-Resistant Structures, WIT Press, Southampton, UK.
  13. Komodromos, P., Polycarpou, P.C., Papaloizou, L. and Phocas, M.C. (2007), "Response of seismically isolated buildings considering poundings", Earthq. Eng. Struct. Dyn., 36(12), 1605-1622. https://doi.org/10.1002/eqe.692.
  14. Kontoni, D.P.N. and Farghaly, A.A. (2019), "The effect of base isolation and tuned mass dampers on the seismic response of RC high-rise buildings considering soil-structure interaction", Earthq. Struct., 17(4), 425-434. https://doi.org/10.12989/eas.2019.17.4.425.
  15. Krishnamoorthy, A. and Anita, S. (2016), "Soil-structure interaction analysis of a FPS-isolated structure using finite element model", Struct., 5, 44-57. https://doi.org/10.1016/j.istruc.2015.08.003.
  16. Mahmoud, S. and Austrell, P.E. and Jankowski, R. (2012), "Simulation of the response of base-isolated buildings under earthquake excitations considering soil flexibility", Earthq. Eng. Eng. Vib., 11, 359-374. https://doi.org/10.1007/s11803-012-0127-z.
  17. Matsagar, V.A. and Jangid, R.S. (2003a), "Seismic response of base-isolated structures during impact with adjacent structures", Eng. Struct., 25(10), 1311-1323. https://doi.org/10.1016/S0141-0296(03)00081-6.
  18. Matsagar, V.A. and Jangid, R.S. (2010), "Impact response of torsionally coupled base-isolated structures", J. Vib. Control, 16(11), 1623-1649. https://doi.org/10.1177/1077546309103271.
  19. Mavronicola, E.A., Polycarpou, P.C. and Komodromos, P. (2017), "Spatial seismic modeling of base-isolated buildings pounding against moat walls: Effects of ground motion directionality and mass eccentricity", Earthq. Eng. Struct. Dyn., 46(7), 1161-1179. https://doi.org/10.1002/eqe.2850.
  20. Mavronicola, E.A., Polycarpou, P.C. and Komodromos, P. (2020), "Effect of ground motion directionality on the seismic response of base isolated buildings pounding against adjacent structures", Eng. Struct., 207, 110202. https://doi.org/10.1016/j.engstruct.2020.110202.
  21. Miari, M. and Jankowski, R. (2022a), "Analysis of pounding between adjacent buildings founded on different soil types", Soil Dyn. Earthq. Eng., 154, 107156. https://doi.org/10.1016/j.soildyn.2022.107156.
  22. Miari, M. and Jankowski, R. (2022b), "Seismic gap between buildings founded on different soil types experiencing pounding during earthquakes", Earthq. Spectra, 38(3), 2183-2206. https://doi.org/10.1016/j.soildyn.2022.107156.
  23. Mylonakis, G. and Gazetas, G. (2000), "Seismic soil-structure interaction: Beneficial or detrimental?", J. Earthq. Eng., 4(3), 277-301. https://doi.org/10.1080/13632460009350372.
  24. Naeim, F. and Kelly, J.M. (1999), Design of Seismic Isolated Structures, John Wiley & Sons Inc., Hoboken, NJ, USA.
  25. Nikolaou, S., Mylonakis, G., Gazetas, G. and Tazoh, T. (2001), "Kinematic pile bending during earthquakes: Analysis and field measurements", Géotech., 51(5), 425-440. https://doi.org/10.1680/geot.51.5.425.39973.
  26. Pant, D.R. and Wijeyewickrema, A.C. (2012), "Structural performance of a base-isolated reinforced concrete building subjected to seismic pounding", Earthq. Eng. Struct. Dyn., 41(12), 1709-1716. https://doi.org/10.1002/eqe.2158.
  27. Wu, W. and Chen, C. (2001), "Simple lumped‐parameter models of foundation using mass‐spring‐dashpot oscillators", J. Chin. Inst. Eng., 24(6), 681-697. https://doi.org/10.1080/02533839.2001.9670665.