DOI QR코드

DOI QR Code

Verification of Nonlinear Numerical Analysis for Seismic Response of Single Degree of Freedom Structure with Shallow Foundation

비선형 수치해석을 통한 단자유도 얕은기초 구조물의 지진 응답특성 검증

  • 추연욱 (KAIST 건설 및 환경공학과) ;
  • 이진선 (원광대학교 토목환경공학과) ;
  • 김동수 (KAIST 건설 및 환경공학과)
  • Received : 2012.11.26
  • Accepted : 2013.02.05
  • Published : 2013.03.29

Abstract

Seismic response of single degree of freedom system supported by shallow foundation was analyzed by using nonlinear explicit finite difference element code. Numerical analysis results were verified with dynamic centrifuge test results of the same soil profile and structural dimensions with the numerical analysis model at a centrifugal acceleration of 20 g. Differences between the analysis and the test results induced by the boundary conditions of control points can be reduced by adding additional local damping to the natural born cyclic hysteretic damping of the soil strata. The analysis results show good agreement with the test results in terms of both time histories and response spectra. Thus, it can be concluded that the nonlinear explicit finite difference element code will be a useful technique for estimating seismic residual displacement, earthpressure etc. which are difficult to measure during laboratory tests and real earthquake.

본 논문에서는 얕은기초를 가지는 단자유도 구조물의 지진시 응답특성을 시간영역 비선형 유한차분해석을 이용하여 살펴보았다. 해석결과는 중력가속도 20g에서 시행된 동일한 제원을 가지는 동적원심모형실험 결과를 통하여 검증되었다. 검증결과 실험과 해석의 통제운동지점 경계조건 차이에서 발생하는 차이는 지반의 비선형 거동특성으로 발생하는 이력감쇠에 지반의 감쇠비를 추가하여 감소시킬 수 있었다. 이로부터 얻어진 구조물과 지반에서 계측된 가속도 시간이력 및 주파수대역 응답곡선 모두 유사한 결과를 나타내어, 시간영역 비선형 유한차분해석을 통한 지반-구조물 상호작용 해석의 신뢰성을 확보할 수 있었으며, 향후 동적원심모형으로 계측이 어려운 구조물의 잔류변위, 작용토압 등을 효과적으로 판단할 수 있을 것으로 사료된다.

Keywords

References

  1. 건설도서 (1999), 도로교의 내진설계계산예(토목구조물 설계계산예 시리즈), 건설도서, 서울, pp.5-9.
  2. Belytschko, T. (1983), "An Overview of Semidiscretization and Time Integration Procedures", in Computational Methods for Transient Analysis, Ch. 1, Elsevier Science Publishers, New York, pp.1-65.
  3. Hardin, B. O. and Drnevich, V. P. (1972), "Shear Modulus and Damping in Soils: Design Equation and Curves", Journal of Soil Mechanics and Founddation Engineering Division, ASCE, Vol.98, No.7, pp.667-691.
  4. Idriss, I. M. and Sun, J. I. (1992), User's Manual for SHAKE91, Center for Geotechnical Modeling Department of Civil & Environmental Engineering, UC Davis, pp.7.
  5. Itasca (2011), FLAC (Fast Lagrangian Analysis of Continua) 3D User's Manual, Itasca Consulting Group, Minneapolis, MN.
  6. Kim, S. and Stewart, J. P. (2003), "Kinematic Soil-structure Interaction from Strong Motion Recordings", Journal of Geotechnical & Geoenvironmental Engineering, ASCE, Vol.129, No.4, pp.323-335. https://doi.org/10.1061/(ASCE)1090-0241(2003)129:4(323)
  7. Kim, D. K., Park, H. G., Kim, D. S., and Lee, S. H. (2010), "Numerical Simulation of Soil-Structure Interaction in Centrifuge Shaking Table System", Proceedings of Korean Geotechnical Society Fall National Conference, September 10, Gyeonggi, Korea
  8. Kim, D. S., Lee, S. H., Choo, Y. W., and Rames, D. (2012), "Self-balanced Earthquake Simulator on Centrifuge and Dynamic Performance Verification", KSCE Journal of Civil Engineering (Accepted).
  9. Kuhlemeyer, R. L. and Lysmer, J. (1973), "Finite Element Method Accuracy for Wave Propagation Problems", Journal of Soil Mechanics and Founddation Engineering Division, ASCE, Vol.99, No.5, pp. 421-427.
  10. Lee, S. H., Kim, D. S., Choo, Y. W., Park, H. G., and Kim, D. G. (2010), "Dynamic Centrifuge Modelling for Evaluating Seismic Loads of Soil-Foundation-Structures", Proceedings of Korean Geotechnical Society Fall National Conference, September 10, Gyeonggi, Korea.
  11. Lee, S. H., Choo, Y. W., and Kim, D. S. (2013), "Performance of An Equivalent Shear Beam (ESB) Model Container for Dynamic Geotechnical Centrifuge Tests", Soil Dynamics and Earthquake Engineering, Vol.44, No.1, pp.102-114. https://doi.org/10.1016/j.soildyn.2012.09.008
  12. Lysmer, J. and Kuhlemeyer, R. L. (1969), "Finite Dynamic Model for Infinite Media," Journal of Engineering Mechanics, Vol.95, No.4, pp.859-877.
  13. Mejia, L. H. and Dawson, E. M. (2006), "Earthquake Deconvolution for FLAC", Proceedings of 4th International FLAC Symposium on Numerical Modeling in Geomechanics, Madrid, Spain, ISBN 0-9767577-0-2, pp.04-10.
  14. Rayhani, M. H. T. and Naggar, M. H. EI. (2008), "Numerical Modeling of Seismic Response of Rigid Foundation on Soft Soil", International Journal of Geomechanics, ASCE, Vol.8, No.6, pp. 336-346. https://doi.org/10.1061/(ASCE)1532-3641(2008)8:6(336)