DOI QR코드

DOI QR Code

Wave Passage Effect on the Seismic Response of a Building considering Bedrock Shear Wave Velocity

기반암의 전단파속도를 고려한 지진파의 통과시차가 건물의 지진거동에 미치는 영향

  • Kim, Yong-Seok (Department of Architectural Engineering, Mokpo National University)
  • 김용석 (국립목포대학교 건축공학과)
  • Received : 2013.10.25
  • Accepted : 2014.01.29
  • Published : 2014.03.03

Abstract

Spatial variations of a seismic wave are mainly wave passage and wave scattering. Wave passage effect is produced by changed characteristics of exciting seismic input motions applied to the bedrock. Modified input motions travel horizontally with time differences determined by apparent shear wave velocity of the bedrock. In this study, wave passage effect on the seismic response of a structure-soil system is investigated by modifying the finite element software of P3DASS (Pseudo 3-Dimensional Dynamic Analysis of a Structure-soil System) to apply inconsistent (time-delayed) seismic input motions along the soft soil-bedrock interface. Study results show that foundation size affected on the seismic response of a structure excited with inconsistent input motions in the lower period range below 0.5 seconds, and seismic responses of a structure were decreased considerably in the lower period range around 0.05 seconds due to the wave passage. Also, shear wave velocity of the bedrock affected on the seismic response of a structure in the lower period range below 0.3 seconds, with significant reduction of the seismic response for smaller shear wave velocity of the bedrock reaching approximately 20% for an apparent shear wave velocity of 1000m/s at a period of 0.05 seconds. Finally, it is concluded that wave passage effect reduces the seismic response of a structure in the lower period range when the bedrock under a soft soil is soft or the bedrock is located very deeply, and wave passage is beneficial for the seismic design of a short period structure like a nuclear container building or a stiff low-rise building.

Acknowledgement

Supported by : 목포대학교

References

  1. Ancheta TD, Stewart JP, Abramhamson NA. Engineering characterization of earthquake ground motion coherency and amplitude variability. Proceedings of the 4th International Symposium on Effects of Surface Geology on Seismic Motion; 2011 Aug 23-26; University of California Santa Barbara: IASPEI/IAEE;c2011.
  2. Clough RW, Penzien J. Dynamics of Structures, McGraw-Hill, New York; c1975. 634 p.
  3. Ancheta DT. Engineering Characterization of Spatially Variable Earthquake Ground Motions, Ph.D. dissertation of University of California, Los Angeles; c2010. 220 p.
  4. Ohsaki M. Sensitivity of Optimum Design for Spatially Varying Ground motions. Journal of Structural Engineering, ASCE. 2001 November; 127(11):1324-1329. https://doi.org/10.1061/(ASCE)0733-9445(2001)127:11(1324)
  5. Kwon JS, Paik InY, Chang SP. Dynamic Analysis of Floating Bridge subject to Earthquake Load Considering Multi-Support Excitation. Journal of the Earthquake Engineering Society of Korea. 2004;8(2):27-33. https://doi.org/10.5000/EESK.2004.8.2.027
  6. Kim IT, Han JW, Yun S, Park DH. Prediction of Tunnel Response by Spatially Variable Ground Motion. Journal of Korean Geo-Environmental Society. 2008 June;9(4):53-61.
  7. Lee EH. Effect of Spatial Incoherence in Seismic Input Motion on Seismic Response of Nuclear Power Plant, M.S. Thesis, Department of Civil and Environmental Engineering, Chonnam National University;c2008. 128 p.
  8. Kim YS. Dynamic Response of Structures on Pile Foundations, Ph.D. Dissertation, The University of Texas at Austin;c1987. 272 p.
  9. Kim YS, Roesset JM. Effect of Nonlinear Soil Behavior on the Inelastic Seismic Response of a Structure. The International Journal of Geomechanics, ASCE. 2004 June;4(2):104-114. https://doi.org/10.1061/(ASCE)1532-3641(2004)4:2(104)
  10. Kausel E. Forced Vibrations of Circular Foundations on Layered Media. Research Report R74-11, Department of Civil Engineering, MIT; 1974.
  11. International Building Code Council (IBC). International Building Code (IBC2009); c2009;p.340-366.
  12. PEER Strong Earthquake Data Base, http://peer.berkeley.edu/smcat/search.html/.
  13. Mylonakis G, Nikolaou S, Gazetas G. Footings under seismic loading: Analysis and design issues with emphasis on bridge foundations. Soil Dyn. & Eqk. Engrg. 2006;26:824-853. https://doi.org/10.1016/j.soildyn.2005.12.005