한국지반공학회논문집 (Journal of the Korean Geotechnical Society)

  • 제20권2호
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  • Pages.15-26
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  • 2004
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  • 1229-2427(pISSN)
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  • 2288-646X(eISSN)
한국지반공학회 (Korean Geotechnical Society)
권호 표지

직접단순전단시험을 이용한 동적이력 후 세립토의 강도 및 강성 예측법

An Estimating Method for Post-cyclic Strength and Stiffness of Eine-grained Soils in Direct Simple Shear Tests

  • 발행 : 2004.03.01
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초록

반복삼축시험에 의한 반복하중 후 강도 및 강성의 예측법을 이용하여, 세립토에 대해서 직접단순 전단시험에서도 그 방법의 사용 가능성을 확인하여 보았다. 사용한 흙은 실트질 점토, 소성 실트와 비소성 실트이다. 반복삼축시험을 통해서 얻은 강도 및 강성 예측법을 직접단순 전단시험에 맞게 수정하여 시험 결과와 비교하였다. 특히, 세립토의 소성지수와 초기전단응력(ISSS)의 영향이 강조되었다. 연구결과는 (i) 세립토의 액상화강도비는 소성지수의 감소와 초기전단응력의 증가에 따라 감소한다. (ii)등가강성과 전단변형률의 관계에 미치는 소성지수와 초기전단응력의 영향은 그리 크지 않다. (iii) 정규화한 과잉간극수압의 증가에 따른 강도비의 저하는 세립토의 소성지수가 증가할수록 느리다. (iv) 활성도가 큰 소성실트의 강성은 과잉간극 수압의 증가에 따라 급속히 감소한다. (v) 반복삼축시험 결과를 이용한 반복하중후 강도 및 강성의 예측법을 이용하여 직접단순 전단시험 결과에 수정한 방법은 시험결과와 잘 어울리는 것으로 나타났다.

Based on an estimating method for post-cyclic strength and stiffness with cyclic triaxial tests proposed by one of the authors, cyclic Direct Simple Shear (DSS) tests were carried out to confirm whether the method can be adapted to DSS test on fine-grained soils: silty clay, plastic silt, and non-plastic silt. Results from cyclic and post-cyclic DSS tests were interpreted by a modified method as adopted for cyclic and post-cyclic triaxial tests. In particular, influence of plasticity index for fine-grained soils and initial static shear stress (ISSS) was emphasised. Findings obtained from the present study are: (i) liquefaction strength ratio of fine-grained soils decreases with decreasing plasticity index and increasing ISSS; (ii) plasticity index and ISSS did not markedly influence relation between equivalent cyclic stiffness and shear strain relations; (iii) the higher the plasticity index of fine-grained soils is, the less the strength ratio decreases with increment of a normalcies excess pore water pressure (NEPWP); (iv) stiffness ratio of plastic silt has large activity decrease rapidly with increasing excess pore water pressure; and (v) post-cyclic strength and stiffness results from DSS tests agree well with those predicted by the method modified from a procedure used for triaxial test results.

키워드

참고문헌

  1. J. Geotechnique v.16 no.1 Direct simple-shear test on Norwegian quick clay Bjerrum,L.;Landva,A. https://doi.org/10.1680/geot.1966.16.1.1
  2. Canadian Geotechnical Journal v.35 no.1 Behavior of a Fine-grained Soil during the Loma Prieta Earthquake Boulanger,M.W.;Meyers,L.H.;Mejia,L.H.;Idriss,I.M. https://doi.org/10.1139/cgj-35-1-146
  3. The 1999 Kocaeli Earthquake, Turkey - investigation into the damage to civil engineering structures, Japanese Society of Civil Engineering Hamada,M.;Tohma,J.;Aydan,O.
  4. J. the Soil Mech. and Foundations Division v.98 no.7 Shear moduhs and damping in soils: Design equations and curves Hardin,B.O.;Drnevich,V.P.
  5. Soils and Foundations v.34 no.1 Undrained cyclic and monotinic trixial behaviour of saturated loose sand Hyodo,M.;Tanimizu,H.;Yasufuku,N.;Murata,H. https://doi.org/10.3208/sandf1972.34.19
  6. Soils and Foundations v.34 no.4 Undrainded cyclic shear behaviour of normally consolidated clay subjected to initial static shear stress Hoydo,M.;Yamomoto,Y.;Sugiyama,M. https://doi.org/10.3208/sandf1972.34.4_1
  7. Reports on the investigations of the 1999 Kokaeli Earthquake in Turkey and the 1999 Chichi Earthquake in Taiwan Japanese Geotechnical Society
  8. The Method of Soil Test and Explanation (1st Edition) Japanese Geotechnical Society
  9. Soil Mechanics - Theory and application Kim,S.K.
  10. Proc. 9th ICSMFE v.2 Stress-deformational and strength characterisics Ladd,C.C.;Foott,R.;Ishihara,K.;Schlosser,F.;Poulos,H.G.
  11. Soils and Foundations v.32 no.2 Estimation of shear characteristics degradation and stress- strain relation of saturated clays after cyclic loading Matsui,T.;Bahr,M.;Abe,N. https://doi.org/10.3208/sandf1972.32.161
  12. J. Geotech. Eng. Div. v.106 no.10 Cyclic stress-strain history and shear characteristics of clay Matsui,T.;Ohara,H.;Itou,T.
  13. J. Geotech Eng. v.106 no.11 Cam-clay predictions of undrained strength Mayne,P.W.
  14. IS-Nagoya'97: Deformation and progressive failure in geomehanics Deformation characteristics of liquefied loose sand by triaxial compression tests Nagase,H.;Hirooka,A.;Yanagihata,T.
  15. The 36th Japan National Conference on Soil Mech. and Foundation Eng. Liquefaction during the 2000 Tottori-ken Seibu Earthquake Shimamoto,E.;Numata,A.;Someya,N.;Miwa,S.;Ikeda,T.;Ohno,K.
  16. Lowland Technology International v.5 no.1 The influence of initial static shear stress on post-cyclic degradation of non-plastic silt Song,B.W.
  17. 2003 Annual Conference of Korean Geo-environmental Society Post-cyclic degradation of strength and stiffiness for non-plastic silt Song, Byung-Woong;Kim, Hong-Taek;Yasuhara,K.;Murakami,S.;Park, Inn-Joon
  18. J. of Geotech. and Geoenv. Eng. v.124 no.2 Fourth Avenue landslide during 1964 Alaskan Earthquake Stark,T.;Contreras,I. https://doi.org/10.1061/(ASCE)1090-0241(1998)124:2(99)
  19. Soils and Foundations v.23 no.1 Effect of static shear on resistance to liquefaction Vaid,Y.P.;Chern,J.C. https://doi.org/10.3208/sandf1972.23.47
  20. Proc. 11th ICSMFE v.1 Soil mechanics-property characterization and analysis procedures Wroth,C.P.;Houlsby,G.T.
  21. J. Soils and Foundations v.32 no.1 The mechanism and a simplified procedure for the analysis of permanent ground displacement due to liquefaction Yasuda,S.;Nagase,H.;Kiku,H.;Uchida,Y. https://doi.org/10.3208/sandf1972.32.149
  22. Proc. 1st International Conference on Earthquake Geotechnical Eng. v.2 Stress-strain relationships of liquefied sands Yasuda,S.;Nagase,H.;Mine,K.;Yoshida,N.;Kiku,H.;Masuda,T.
  23. Proc. 11th ICSMFE v.2 Undrained and drained cyclic triaxial tests on marine clay Yasuhara,K.
  24. J. Geotechnical Eng. v.120 no.11 Postcylic undrained strength for cohesive soils Yasuhara,K. https://doi.org/10.1061/(ASCE)0733-9410(1994)120:11(1961)
  25. J. Geotech. and Geoenv. Eng. v.123 no.3 Method for estimating postcyclic undrained secant modulus of clays Yasuhara,K.
  26. Discussion, Canadian Geotehnical Journal v.36 no.3 Behaviour of a fine-grained soil during the Loma Prieta earthquake Yasuhara,K. https://doi.org/10.1139/t99-026
  27. Proc. 14th ICSMFE v.1 Effects of initial static shear stress on post-cyclic degradation of a plastic silt Yasuhara,K.;Toyota,N.
  28. Soil and Foundation v.32 no.1 Effects of cyclic loading on undrained strength and compressibility of clay Yasuhara,K.;Hirao,K.;Hyde,A.F.L. https://doi.org/10.3208/sandf1972.32.100
  29. Proc. IUTAM Symp. Seabed Meth. Undrained shear behavior of quasi-overconsolidated clay induced by cyclic loading Yasuhara,K.;Fujiwara,H.;Hirao,K.;Ue,S.
  30. Proc. Symp. on Mechanics of Overconsolidated Soil and Ground Post-cyclic degradation of strength and stiffness on overconsolidated plastic silt Yasuhara,K.;Murakami,S.;Yokokawa,S.;Song,B.W.