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Analysis of Response Characteristics According to Permanent Displacement in Seismic Slope

지진시 비탈면의 영구변위 발생에 따른 응답특성 분석

  • Ahn, Jae-Kwang (Earthquake and Volcano Research Division, KMA) ;
  • Park, Sangki (Multi-Disaster Countermeasures Organization, KICT) ;
  • Kim, Wooseok (Dept. of Infrastructure Safety Research, KICT) ;
  • Son, Su-Won (Seismic Simulation Test Center, Pusan National Univ.)
  • 안재광 (기상청 지진화산연구과) ;
  • 박상기 (한국건설기술연구원 복합재난연구단) ;
  • 김우석 (한국건설기술연구원 인프라안전연구본부) ;
  • 손수원 (부산대학교 지진방재연구센터)
  • Received : 2019.12.02
  • Accepted : 2019.12.13
  • Published : 2019.12.31

Abstract

The slope collapse can be classified into internal and external factors. Internal factors are engineering factors inherent in the formation of slopes such as soil depth, slope angle, shear strength of soil, and external factors are external loading such as earthquakes. The external factor for earthquake can be expressed by various values such as peak ground acceleration (PGA), peak ground velocity (PGV), Arias coefficient (I), natural period (Tp), and spectral acceleration (SaT=1.0). Specially, PGA is the most typical value that defines the magnitude of the ground motion of an earthquake. However, it is not enough to consider the displacement in the slope which depends on the duration of the earthquake even if the vibration has the same peak ground acceleration. In this study, numerical analysis of two-dimensional plane strain conditions was performed on engineered block, and slope responses due to seismic motion of scaling PGA to 0.2 g various event scenarios was analyzed. As a result, the response of slope is different depending on the presence or absence of sliding block; it is shown that slope response depend on the seismic wave triggering sliding block than the input motion factors.

비탈면 붕괴는 크게 내적요인과 외적요인으로 분류할 수 있다. 내적요인은 토층 깊이, 사면경사, 흙의 전단강도 등의 기존에 비탈면의 형성과 함께 내재 되어있는 공학적 요인이며, 외적요인은 지진과 같은 하중이다. 이때 최대가속도(PGA), 최대속도(PGV), Arias계수(I), 고유주기(Tp), 스펙트럼 가속도(SaT=1.0) 등은 지진의 외적요인으로 대변되는 값이다. 특히, 최대지반가속도(peak ground acceleration, PGA)는 지진의 지반 운동 크기를 정의하는 가장 대표적인 값이지만 동일한 최대 지반가속도 값을 가지는 진동이라도 지진의 지속시간에 따라 달라지는 사면에서의 변위를 충분히 고려하지 못하는 단점을 가지고 있다. 본 연구에서는 인공사면을 대상으로 2차원 평면변형률 조건의 수치해석을 수행하였으며, 다양한 지진 시나리오의 PGA를 0.2g로 스케일링하여 적용했을 때 비탈면에서 발생하는 응답특성을 분석하였다. 분석 결과, 비탈면의 상층부와 하층부의 응답은 활동면 발생 여부에 따라 차이를 보이며, 입력 지진파의 외적요인 보다는 소성변형을 유발시킨 진동 특성의 영향을 받는 것으로 나타났다.

Keywords

References

  1. Ambraseys, N. and Menu, J. (1988), "Earthquake Induced Ground Displacements", Earthquake engineering & structural dynamics, Vol.16, No.7, pp.985-1006. https://doi.org/10.1002/eqe.4290160704
  2. Bray, J.D. and Travasarou, T. (2009), "Pseudostatic Coefficient for Use in Simplified Seismic Slope Stability Evaluation", Journal of Geotechnical and Geoenvironmental Engineering, Vol.135, No.9, pp.1336-1340. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000012
  3. Darendeli, M.B. (2001), Development of a new family of normalized modulus reduction and material damping curves, Ph.D. Dissertation, University of Texas at Austin.
  4. Federal Emergency Management Agency (2003), HAZUS-MH MR4 Technical Manual: FEMA, Washington, DC.
  5. Huang, Y., Zhao, L., Xiong, M., Liu, C., and Lu, P. (2018), "Critical slip surface and landslide volume of a soil slope under random earthquake ground motions", Environmental earth sciences, Vol.77, No.23, pp.787. https://doi.org/10.1007/s12665-018-7974-5
  6. Itasca (2011), FLAC:Fast Lagrange Analysis of Continua, Version 7.0, Minneapolis: Itasca Consulting Group, Inc.
  7. Jibson, R.W. (2007), "Regression Models for Estimating Coseismic Landslide Displacement", Engineering Geology, Vol.91, No.2, pp. 209-218. https://doi.org/10.1016/j.enggeo.2007.01.013
  8. Keefer, D.K. (1984). "Landslides caused by earthquakes", Geological Society of America Bulletin, Vol.95, No.4, pp.406-421. https://doi.org/10.1130/0016-7606(1984)95<406:LCBE>2.0.CO;2
  9. Kwok, A.O.L., Stewart, J.P., Hashash, Y.M.A., Matasovic, N., Pyke, R., Wang, Z., and Yang, Z. (2007), "Use of Exact Solutions of Wave Propagation Problems to Guide Implementation of Nonlinear Seismic Ground Response Analysis Procedures", Journal of Geotechnical and Geoenvironmental Engineering, Vol.133, pp.1385. https://doi.org/10.1061/(ASCE)1090-0241(2007)133:11(1385)
  10. Kuhlemeyer, R. L. and Lysmer, J. (1973), "Finite Element Method Accuracy for Wave Propagation Problems", Journal of Soil Mechanics & Foundations Div, Vol.99, Tech Rpt.
  11. Ministry of Land, Infrastructure and Transport (MOILT) (2016), Design Criteria of Slope (in Korean).
  12. Lee, J.H., Ahn, J.K., and Park, D. (2015), "Prediction of seismic displacement of dry mountain slopes composed of a soft thin uniform layer", Soil Dynamics and Earthquake Engineering, Vol.79, pp.5-16. https://doi.org/10.1016/j.soildyn.2015.08.008
  13. Lysmer, J. and Kuhlemeyer, R. (1969), "Finite Element Model for Infinite Media", Journal of Engineering Mechanics Division, ASCE, Vol.95, pp.859-877. https://doi.org/10.1061/JMCEA3.0001144
  14. Makdisi, F.I. and Seed, H.B. (1978), "Simplified Procedure for Estimating Dam and Embankment Earthquake-induced Deformations", Journal of the Geotechnical Engineering Division, Vol.104, No.GT7, pp.849-867. https://doi.org/10.1061/AJGEB6.0000668
  15. Park, D., Kim, T. G., Ahn, J.K., and Park, I.J. (2013), "Amplification characteristics of Mountain Slopes", Journal of Korean Society of Hazard Mitigation, Vol.13, No.2, pp.117-123. https://doi.org/10.9798/KOSHAM.2013.13.2.117
  16. Park, D.H., Shin, J.H., and Yun, S.U. (2010), "Seismic analysis of tunnel in transverse direction part II: Evaluation of seismic tunnel response via dynamic analysis", Journal of the Korean Geotechnical Society, Vol.26, No.6, pp.71-85.
  17. Park, S., Kim, W., Lee, J., and Baek, Y. (2018), "Case Study on Slope Stability Changes Caused by Earthquakes-Focusing on Gyeongju 5.8 ML EQ", Sustainability, Vol.10, No.10, pp.3441. https://doi.org/10.3390/su10103441
  18. Rathje, E.M. and Bray, J.D. (2001), "One- and two-dimensional seismic analysis of solid-waste landfills", Canadian Geotechnical Journal, Vol.384, pp.850-862. https://doi.org/10.1139/t01-009
  19. Seno, T., Shimazaki, K., Somerville, P., Sudo, K., and Eguchi, T. (1980), "Rupture process of the Miyagi-Oki, Japan, earthquake of June 12, 1978", Physics of the Earth and Planetary Interiors, Vol.23, No.1, pp.39-61. https://doi.org/10.1016/0031-9201(80)90081-3
  20. Strenk, P.M. (2010), Evaluation of analytical procedures for estimating seismically induced permanent deformations in slopes, Ph.D. Dissertation, Dexel University, Philadelphia.
  21. USGS (2009), PAGER-CAT Earthquake Catalog, Version 2008_06.1, United States Geological Survey, 2009.09.04
  22. Varnes DJ. (1978), "Slope movement types and processes", In Landslides Analysis and Control, Schuster RL, Krizek RJ (eds). National Academy of Sciences, Transportation Research Board: Washington DC; 11-33.