Earthquakes and Structures

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Effects of ground motion frequency content on performance of isolated bridges with SSI

  • Neethu, B (Department of Civil Engineering, National Institute of Technology Durgapur) ;
  • Das, Diptesh (Department of Civil Engineering, National Institute of Technology Durgapur) ;
  • Garia, Siddharth (Department of Civil Engineering, National Institute of Technology Durgapur)
  • Received : 2017.04.26
  • Accepted : 2017.11.22
  • Published : 2017.10.25
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Abstract

The present study considers a multi-span continuous bridge, isolated by lead rubber bearing (LRB). Dynamic soilstructure interaction (SSI) is modelled with the help of a simplified, sway-rocking model for different types of soil. It is well understood from the literature that SSI influences the structural responses and the isolator performance. However, the abovementioned effect of SSI also depends on the earthquake ground motion properties. It is very important to understand how the interaction between soil and structure varies with the earthquake ground motion characteristics but, as far as the knowledge of the authors go, no study has been carried out to investigate this effect. Therefore, the objectives of the present study are to investigate the influence of earthquake ground motion characteristics on: (a) the responses of a multi span bridge (isolated and non-isolated), (b) the performance of the isolator and, most importantly, (c) the soil-structure interaction. Statistical analyses are conducted by considering 14 earthquakes which are selected in such a way that they can be categorized into three frequency content groups according to their peak ground acceleration to peak ground velocity (PGA/PGV) ratio. Lumped mass model of the bridge is developed and time history analyses are carried out by solving the governing equations of motion in the state space form. The performance of the isolator is studied by comparing the responses of the bridge with those of the corresponding uncontrolled bridge (i.e., non-isolated bridge). On studying the effect of earthquake motions, it is observed that the earthquake ground motion characteristics affect the interaction between soil and structure in such a way that the responses decrease with increase in frequency content of the earthquake for all the types of soil considered. The reverse phenomenon is observed in case of the isolator performance where the control efficiencies increase with frequency content of earthquake.

Keywords

References

  1. Agarwal, P. and Shrikhande, M. (2006), Earthquake Resistant Design of Structures, Prentice-Hall of India, New Delhi, India.
  2. Constantinou, M.C. and Tadjbakhsh, I.G. (1985), "Hysteretic dampers in base isolation: Random approach", J. Struct. Eng., 111(4), 705-721. https://doi.org/10.1061/(ASCE)0733-9445(1985)111:4(705)
  3. Davoodi, M., Sagjadi, M., Goljahani, P. and Kamalian, M. (2012), "Effects of near-field and far-field earthquakes on seismic response of SDOF system considering soil structure interaction", Proceedings of the 15th World Conference on Earthquake Engineering.
  4. Dicleli, M., Albhaisi, S. and Mansour, M.Y. (2005), "Static soil-structure interaction effects in seismic-isolated bridges", Pract. Period. Struct. Des. Constr., 10(1), 22-33. https://doi.org/10.1061/(ASCE)1084-0680(2005)10:1(22)
  5. Garg, R., Vemuri, J.P. and Subramaniam, K.V.L. (2016), "Correlating peak ground A/V ratio with ground motion frequency content", Proceedings of the Structural Engineering Convention (SEC-2016) CSIR-SERC, Chennai, India, December.
  6. Gazetas, G. (2006), "Seismic design of foundations and soil-structure interaction", Proceedings of the 1st European Conference on Earthquake Engineering and Seismology, Geneva, Switzerland, September.
  7. Ghobarah, A. and Ali, H.M. (1988), "Seismic performance of highway bridges", Eng. Struct., 10, 157-166. https://doi.org/10.1016/0141-0296(88)90002-8
  8. Hameed, A., Koo, M.S., Do, T.D. and Jeong, J.H. (2008), "Effect of lead rubber bearing characteristics on the response of seismic-isolated bridges", KSCE J. Civil Eng., 12(3), 187-196. https://doi.org/10.1007/s12205-008-0187-9
  9. Jafarian, Y., Kermani, E. and Baziar, M.H. (2010), "Empirical predictive model for the vmax/amax ratio of strong ground motions using genetic programming", Comput. Geosci., 36(12), 1523-1531. https://doi.org/10.1016/j.cageo.2010.07.002
  10. Jangid, R.S. (2007), "Optimum lead-rubber isolation bearings for near-fault motions", Eng. Struct., 29(10), 2503-2513. https://doi.org/10.1016/j.engstruct.2006.12.010
  11. Jangid, R.S. (2008), "Equivalent linear stochastic seismic response of isolated bridges", J. Sound Vibr., 309(3-5), 805-822. https://doi.org/10.1016/j.jsv.2007.07.071
  12. Krishnamoorthy, A. (2013), "Effect of soil-structure interaction for a building isolated with FPS", Earthq. Struct., 4(3), 285-297. https://doi.org/10.12989/eas.2013.4.3.285
  13. Kunde, M.C. and Jangid, R.S. (2003), "Seismic behavior of isolated bridges: A-state-of-the-art review", Electr. J. Struct. Eng., 3, 140-170.
  14. Kunde, M.C. and Jangid, R.S. (2006), "Effects of pier and deck flexibility on the seismic response of isolated bridges", J. Brid. Eng., 11(1), 109-121. https://doi.org/10.1061/(ASCE)1084-0702(2006)11:1(109)
  15. Luco, J.E. (2014), "Effects of soil-structure interaction on seismic base isolation", Soil Dyn. Earthq. Eng., 66, 167-177. https://doi.org/10.1016/j.soildyn.2014.05.007
  16. Matsagar, V.A. and Jangid, R.S. (2004), "Influence of isolator characteristics on the response of base-isolated structures", Eng. Struct., 26(12), 1735-1749. https://doi.org/10.1016/j.engstruct.2004.06.011
  17. Naeim, F. and Kelly, J.M. (1999), Design of Seismic Isolated Structures: From Theory to Practice, John Wiley & Sons, Inc., New York, U.S.A.
  18. Neethu, B. and Das, D. (2015), "Influence of passive isolator parameters on seismic response control of multi-span bridges", J. Sci. Res. Publ., 5(4), 1-10.
  19. Papathanasiou, S.M. and Tsopelas, P. (2008), "Soil structure interaction of seismic isolated bridges", J. Struct. Eng., 134(7), 1154-1164. https://doi.org/10.1061/(ASCE)0733-9445(2008)134:7(1154)
  20. Park, K.S., Jung, H.J. and Lee, I.W. (2002), "A comparative study on aseismic performances of base isolation systems for multi-span continuous bridge", Eng. Struct., 24(8), 1001-1013. https://doi.org/10.1016/S0141-0296(02)00020-2
  21. Patil, S. and Reddy, G. (2012), "State of art review-base isolation systems for structures", J. Emerg. Technol. Adv. Eng., 2(7), 438-453.
  22. Raheem, S.E.A. and Hayashikawa, T. (2013), "Soil-structure interaction modeling effects on seismic response of cable-stayed bridge tower", J. Adv. Struct. Eng., 5(1), 8. https://doi.org/10.1186/2008-6695-5-8
  23. Spyrakos, C.C. (1990). "Assessment of SSI on the longitudinal seismic response short span bridges", Constr. Build. Mater., 4(4), 170-175. https://doi.org/10.1016/0950-0618(90)90036-Z
  24. Tongaonkar, N.P. and Jangid, R.S. (2003), "Seismic response of isolated bridges with soil-structure interaction", Soil Dyn. Earthq. Eng., 23(4), 287-302. https://doi.org/10.1016/S0267-7261(03)00020-4
  25. Turkington, D., Carr, A.J. and Moss, P.J. (1989), "Seismic design of bridges on lead-rubber bearings", J. Struct. Eng., 115(12), 3000-3016. https://doi.org/10.1061/(ASCE)0733-9445(1989)115:12(3000)
  26. Vasiliadis, L.K. (2016), "Seismic evaluation and retrofitting of reinforced concrete buildings with base isolation systems", Earthq. Struct., 10(2), 293-311. https://doi.org/10.12989/eas.2016.10.2.293
  27. Wang, Y.P., Chung, L.L. and Liao, W.H. (1998), "Seismic response analysis of bridges isolated with friction pendulum bearings", Earthq. Eng. Struct. Dyn., 27(3), 1069-1093. https://doi.org/10.1002/(SICI)1096-9845(199810)27:10<1069::AID-EQE770>3.0.CO;2-S
  28. Wang, Z., Dueñas-Osorio, L. and Padgett, J.E. (2014), "Influence of soil-structure interaction and liquefaction on the isolation efficiency of a typical multispan continuous steel girder bridge", J. Brid. Eng., 19(8), A4014001. https://doi.org/10.1061/(ASCE)BE.1943-5592.0000526
  29. Wen, Y.K. (1976). "Method for random vibration of hysteretic systems", J. Eng. Mech. Div., 102(2), 249-263.
  30. Zade, M.T. and Najafi, L.H. (2008), "Assessing seismic behavior of eccentrically braced frames (Ebfs) due to near-field ground motions", Proceedings of the 14th World Conference on Earthquake Engineering.
  31. Zhu, T.J., Heidebrecht, A.C. and Tso, W.K. (1988), "Effect of peak ground acceleration to velocity ratio on ductility demand of inelastic systems", Earthq. Eng. Struct. Dyn., 16(1), 63-79. https://doi.org/10.1002/eqe.4290160106
  32. MATLAB (2016a), Matlab Version, The MathWorks, Inc., Natick, Massachusetts, U.S.A.