Journal of the Computational Structural Engineering Institute of Korea (한국전산구조공학회논문집)

Computational Structural Engineering Institute of Korea (한국전산구조공학회)
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Evaluation of Soil-Structure Interaction Responses of LNG Storage Tank Subjected to Vertical Seismic Excitation Depending on Foundation Type

기초형식에 따른 LNG 저장탱크의 지반-구조물 상호작용을 고려한 수직방향 지진응답 분석

  • Son, Il-Min (Department of Architecture and Civil Engineering, Graduate School, Chonnam Univ.) ;
  • Kim, Jae-Min (Department of Civil Engineering, Chonnam Univ.)
  • 손일민 (전남대학교 대학원 건축토목공학과) ;
  • 김재민 (전남대학교 토목공학과)
  • Received : 2019.08.24
  • Accepted : 2019.08.30
  • Published : 2019.12.31
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Abstract

We investigate the effect of soil-structure interaction (SSI) on the response of LNG storage tanks to vertical seismic excitation depending on the type of foundation. An LNG storage tank with a diameter of 71 m on a clay layer with a thickness of 30 m upon bedrock, was selected as an example. The nonlinear behavior of the soil was considered in an equivalent linear method. Four types of foundation were considered, including shallow, piled raft, and pile foundations (surface and floating types). In addition, the effect of soil compaction within the group pile on the seismic response of the tank was investigated. KIESSI-3D, an analysis package in the frequency domain, was used to study the SSI and the stress in the outer tank was calculated. Based on an analysis of the numerical results, we arrived at three main conclusions: (1) for a shallow foundation, the vertical stress in the outer tank is less than the fixed base response due to the SSI effect; (2) for foundations supported by piles, the vertical stress can be greater than the fixed base stress due to the increase in the vertical impedance due to the piles and the decrease in radiation damping; and (3) soil compaction had a miniscule impact on the seismic response of the outer tank.

논문에서는 수직방향 지진입력에 의한 지반-구조물 상호작용 효과가 기초 종류에 따라 LNG 저장탱크의 지진응답에 미치는 효과를 분석하였다. 이를 위하여 직경 71m인 LNG 탱크와 기반암 위 점토지반의 깊이가 30m인 지반조건을 고려하였다. 그리고 기초형식으로 네 가지(얕은 기초, 말뚝지지 전면기초, 말뚝기초(지표면 접촉식, 부유식)를 고려하였다. 지반의 비선형성은 자유장 지반에 대하여 등가선형화기법으로 고려되었다. 또한, 말뚝기초의 시공과정에서 발생하는 동다짐 효과에 대해서도 분석하였다. SSI 해석을 위하여 진동수영역 해석프로그램인 KIESSI-3D를 이용하였다. 지반-구조물 상호작용 해석을 통해 LNG 저장탱크의 외조 벽체 쉘의 응력을 구하였다. 해석결과로부터 다음과 같은 결론을 얻을 수 있었다: (1) 얕은 기초에서 외조탱크의 수직응력은 SSI 효과로 인하여 고정기초응답 보다 작았다. (2) 말뚝으로 지지된 기초에서 말뚝으로 인해 기초의 수직강성이 커지고 방사감쇠가 작아질 수 있기 때문에 SSI 응답이 고정기초응답 보다 커질 수 있다. (3) 동다짐 효과는 수직지진에 의한 LNG 저장탱크의 응답에 미치는 영향이 매우 작았다.

Keywords

References

  1. ANSYS Inc. (2017) ANSYS 17, User's Reference Manual.
  2. API 650 (2013) Welded Tanks for Oil Storage, American Petroleum Institute.
  3. Choi, K.J., Park, D.G., Lee, J.H. (2012) Load Sharing Analysis of Piled Rafts Based on Non-linear Load Settlement Characteristics, J. Korean Geotech. Soc., 28(11), pp.33-40. https://doi.org/10.7843/kgs.2012.28.11.33
  4. Eurocode 8 (2006) Design of Structures for Earthquake Resistance, Part 4: Silos, Tanks and Pipelines, European Committee for Standardization, Brussels.
  5. Ha, J.G., Park, H.J., Lee, M.K., Lee, H.R., Kim, D.S., Kwon, S.Y., Kim, H.U. (2017) Seismic Behavior of LNG Storage Tank Considering Soil Foundation Structure Interaction with Different Foundation Types, 19th International Conference on Soil Mechanics and Geotechnical Engineering.
  6. Hokmabadi A.S., Fatahi, B. (2016) Influence of Foundation Type on Seismic Performance of Buildings Considering Soil-Structure Interaction, Int. J. Struct. Stab. & Dyn., 16(8), 1550043. https://doi.org/10.1142/S0219455415500431
  7. KDS 17 10 00 (2018) Seismic Design General, Korea Construction Standards Center, Ministry of Land, Infrastructure and Transport, Korea.
  8. Kim, J.H., Kim, S.K., Chun, B.S. (2013) A Study on Piled Raft Constructed on Soft Ground through Numerical Analysis, J. Korean Geo Environ. Soc., 14(3), pp.29-34.
  9. Kim, J.M. (2016) Development of World-Best Fundamental Technologies for Nonlinear Fluid Structure Soil Interaction Analysis by Developing p-version Dynamic Infinite Elements and Performing Sloshing Shaking Table Tests, Report No. 14CTAP-C077514-01, Chonnam National University.
  10. Kim, J.M., Chang, S.H., Yun, C.B. (2002) Fluid-Structure-Soil Interaction Analysis of Cylindrical Liquid Storage Tanks Subjected to Horizontal Earthquake Loading, Struct. Eng. & Mech., 13(6) pp.615-638. https://doi.org/10.12989/sem.2002.13.6.615
  11. Kim, M.K., Rhee, J.W., Lee, P.K., Kim, M.K. (2004) A Study of Characteristics of Soil-Pile-Structure Interaction Behavior on the Frequency Contents of the Seismic Waves, J. Comput. Struct. Eng. Inst. Korea, 17(3), pp.295-308.
  12. Lee, E.H., Kim, J.M., Seo, C.G. (2013) Large-scale 3D SSI Analysis using KIESSI-3D Program, J. Comput. Struct. Eng. Inst. Korea, 26(6), pp.439-445. https://doi.org/10.7734/COSEIK.2013.26.6.439
  13. Lim, J.S., Son, I.M., Kim, J.M., Seo, C.G. (2016) A Speed-up in Computing Time for SSI Analysis by p-version Infinite Elements, J. Comput. Struct. Eng. Inst. Korea, 29(5), pp.471-482. https://doi.org/10.7734/COSEIK.2016.29.5.471
  14. Luft, R.U. (1984) Vertical Acceleration in Prestressed Concrete Tanks, ASCE, 110, ST4, pp.706-714. https://doi.org/10.1061/(ASCE)0733-9445(1984)110:4(706)
  15. Park, H.J., Ha, J.G., Kwon, S.Y., Lee, M.G., Kim, D.S. (2017) Investigation of the Dynamic Behaviour of a Storage Tank with Different Foundation Types Focusing on the Soil Foundation Structure Interactions using Centrifuge Model Tests, Earthq. Eng. & Struct. Dyn., 46, pp.2301-2316. https://doi.org/10.1002/eqe.2905
  16. Park, S.Y. (2019) Global LNG Market Change and Domestic Private Power Market Forecast, www.kisrating.com.
  17. Schnabel, P.B., Lysmer, J., Seed, H.B. (1991) SHAKE91, A Computer Program for Earthquake Response Analysis of Horizontal Layered Sites, EERC(Earthquake Engineering Research Center), College of Engineering, University of California Berkeley, California.
  18. Seo, C.G., Kim, J.M. (2012) KIESSI Program for 3-D Soil-Structure Interaction Analysis, Comput. Struct. Eng., 25(3), pp.77-83.
  19. Son, I.M., Kim, J.M., Lee, C.H. (2019) Seismic Soil-Structure Interaction Analyses of LNG Storage Tanks Depending on Foundation Type, J. Comput. Struct. Eng. Inst. Korea, 32(3), pp.155-164. https://doi.org/10.7734/COSEIK.2019.32.3.155
  20. Sun, J., Cui, L. (2015) Seismic Response for Base Isolation of Storage Tanks with Soil-Structure Interaction, Phys. & Numer. Simul. Geotech. Engi., pp.64-68.
  21. Veletsos, A.S., Tang, Y. (1990) Soil-Structure Interaction Effects for Laterally Excited Liquid Storage Tanks, Earthq. Eng. & Struct. Dyn., 19, pp.473-496. https://doi.org/10.1002/eqe.4290190402