A Suggestion of an Empirical Equation for Shear Modulus Reduction Curve Estimation of Sandy Soils

사질토 전단탄성계수 감소곡선 산정을 위한 경험식 제안

  • Park, Dug-Keun (Member, Senior Analyst, National Institute for Disaster Prevention, Ministry of Government Administration and Home Affairs) ;
  • Published : 2002.06.01

Abstract

In dynamic analyses such as seismic ground response and soil-structure interaction problems, it is very crucial to obtain accurate dynamic shear modulus of soil deposit. In this study, an extensive data base of available experimental data is compiled and reanalyzed to establish a simple empirical formula for the dynamic shear modulus reduction curve to cover wide range of strain for sandy soils. The proposed empirical equation is to represent the dynamic shear modulus degradation with strain in terms of low-amplitude dynamic shear modulus and effective mean confining Pressure, since those factors have the most significant effect on the Position and shape of the shear modulus reduction curve for nonelastic soils. If low-amplitude shear modulus is measured, degraded modulus at any shear strain amplitude can be calculated using the proposed equation.

지진에 의한 지반거동 및 지반-구조물 상호작용 등 지반동역학적 문제분석을 위해서는 정확한 동적 토질전단탄성계수의 획득이 필수적이다. 본 연구에서는 기존의 자료를 조사분석하여 어떤 변형율에서도 활용할 수 있는 사질토 전단탄성계수 감소곡선을 위한 경험식을 제안하였다. 비소성 토질의 전단탄성계수 감소곡선의 위치와 모양은 평균유효구속압에 주로 영향을 받으므로 본 연구에서는 이 영향요소 및 최대전단탄성계수를 이용하여 변형을 증가에 의한 전단탄성계수 감소를 산정할 수 있는 방정식을 형성하였다. 최대전단탄성계수가 측정되면 제안된 식을 이용하여 특정 변형을 및 구속압에서 감소된 전단탄성계수를 산출할 수 있을 것이다.

Keywords

References

  1. Alarcon-Guzmar, A. (1986), Cyclic StresSi-Strain and LiquefactionChurcicterifitics of Sands, Ph.D. Dissertation, Purduc Univcrsity,West Lafayette, Indiana, 591p
  2. Borden, R. H., Shao, L., and Gupta, A. (1996), 'Dynamic Pro-perties of Piedmont Residual Soils,' .J Geotech. Engrg., ASCE,Vo1.122, No.lO, pp.813-821
  3. Dobry, R. and Vucetic, M. (1987), 'Dynamic Properties andSeismic Response of Soft Clay Deposits,' Proceedings. Int Sympon Geotech Engrg. of Soft Soils, Mexico City, Vo1.2, pp.51-87
  4. Edil, T. B. and Luh, G. F. (1978), 'Dynamic Modulus andDamping Relaticnship for Sands,'Proceedings, Earthquake Engrgand Soil Dynamics, Pasadena, CA., ASCE, Vol.l, pp.394-409
  5. Hardin, B. O. (1978), 'The Nature of Stress-Strain Behavior lorSoils,' Proceedings, Earthquake Engrg. and SoiI Dynamics, Pasadena,CA., ASCE, Vol.1, pp.3-90
  6. Hardin, B. 0. and Black, W. L. (1968), 'Vibration Modulus ofNonnally Consolidated Clay,' J.SMFD, ASCE, Vo1.94, No.SM2,pp.353-369
  7. Hardin, B. O. and Black, W. L. (1969), 'Vibration Modulus ofNormally Consolidated CIay-CIosure,' J. SMFD, ASCE, Vol.95, No.SM6, pp. 1531-1537
  8. IIardin, B. O. and Dmevich, V. P. (1972a), 'Shear Modulus andDamping in Soili: Measurement and Parameter Effects,' J SMFD,ASCE, Vo1.98, No.SM6, pp.603-624
  9. Hardin, B. O. and Dmevich, V. P. (1972b), 'Shear Modulus andDaming in Soils: Design Equations and Curves,' J. SMFD,ASCE, Vol.98, No.SM7, pp.667-692
  10. Hardin, K. O., Drnevich, V. P., Wang, J., and Sams, C. E. (1994),'Resonant Colurnn Testing at Pressures up to 3.5 MPa (500 psi),'Dynamic Geotechnical Testing II. ASTM STP 1213, ASTM, pp.222-233
  11. Hryciw, R. D. and Thomann, T. G. (1993), 'Stress-History-BasedModel for Ge of Cohesionless Soils,' J. Geotech. Engrg., ASCE,Vo1.119, No.7, pp.1073-1093
  12. Ishibashi, I. (1981), 'Dynamic Soil Properties,' Proceedings, JointUS-PRC Microzonation Workshop, Harbin, China, pp.16.1-16.21
  13. Ishibashi, I. (1992), Discussion to 'Effect of Soil Plasticity onCyclic Response,' by Vucetic and Dobry (1991), J. GeotechEngrg., ASCE, Vol.118, No.5, pp.830-832
  14. Ishibashi, I. and Zhang, X. (1993), 'Unified Dynamic Shear Moduliand Damping Ratios of Sand and Clay,' Soils and FoundationsJSSMFE, Vol.33, No.1, March, pp. 182-191
  15. Iwasaki, T. and latsuoka, F. (1977), 'Effects of Grain Size andGrading on Dynamic Shear Moduli of Sands,' SoiIs and Foundationf,JSSMFE, Vol.17, No.3, pp. 19-35
  16. Iwasaki, T., Tatsuoka, F., and Takagi, Y. (1978), 'Shear Moduliof Sands under Cyclic Torsional Shear Loading' Soils and Foundations,JSSMFE, Vol.18, No.1, pp.39-56
  17. Kanatam. M., Nishi, K., and Tanaka, Y. (1994), 'DynamicProperties of Sand at Low Confining Pressure' Proceedings, Int.Symp. on Pre-failure Deformation of Geomatenats, Vol.1, pp.37-40
  18. Khouri, N. Q. (1984), Dynamic Propertieh of Sods, M. S. Thesis,Syracuse Univ., NY., 304p
  19. K.im, D. S. and Stokoe, K. H., Ⅱ, and Hudson, W. R. (1991),'Deformational Characteristics of Soils at Small to IntcrmediatcStrains from Cyclic Tests,' Research Report 1177-3, Center forTransportion Research, Bureau of Engrg. Research, The Univ. ofTexas at Austin, Texas, 142p
  20. Kokusho, I. (1980), 'Cyclic Triaxial Test of Dynamic Soil Propertiesfor Wide Strain Range,' Proceedings. Seventh World Conferenceon Earthquake Engineerin, Istanbul, Turkcy, Vol.3, pp.305-312
  21. Kokusho, T. and Esashi, Y. (1981), 'Cyclic Triaxial rest on Sandsand Coursc Matcrials,' Proceedings, Tenth Int. Conference on SMFE, Stockholm, Vol.1, pp.673-676
  22. Kramer, S. L. (1996), Geotechnical Earthquake Enemeenng, Prentice Hall, Uppcr Saddlc Rivcr, NJ., 653p
  23. Ladd, R. S., Dob·, R., Dutko, P., Yokel, F. Y., and Chung, R. M.(1989), 'Pore-Water Pressure Buildup in Clean Sands Because of Cyclic Strainin,' Geotechmcal Testing Journal, ASTM, Vol.12,No.1, pp.77-86
  24. Macari, E. J. and Ko, H. Y. (1994), 'A Study of an Anisotropically Overconsolidated Silt by the Resonant Column Method,' GeotechmcaITesting Journal, ASTM, Vol.17, No.3, pp.315-324
  25. Ni, S. H. (1987), Dynamic Properties of Sand under True TritixialStress Ststes from Resonant/Column Torsionat Shear Tests, Ph.D. Dissertation, The Univ. of Texas at Austin, Texas, 422p
  26. Porovic, E. and Jardine, R. J. (1994), 'Some Observation on theStatic and Dynamic Shear Stiffness of Ham River Sand,' Proceedings,Int Symp on Pre-failure Deformation of Geomatenats, Vol.1,pp.25-30
  27. Ramberg, W. and Osgood, W. R. (1943), 'Description of Stress-Strain Curves by Three Parameters,' Technical Note 902, NationalAdvisory Committee for Aeronautics, Washington DC, 1943, 13p
  28. Rampello, S., Viggiani, G., and Silvestri, F. (1994a), 'The Dependenyof Small 론train Siffness on Stress Rate and History for FineGrained Soils: The Example of Vallericca Clay,' Proceedings. Int.mp on Pre-failure Deformutton of Geomatenah, Vol. 1, pp.273-278
  29. Rampello, S., Viegiani, G., and Silvei, F. (1994b), 'PanelistDiscussion: The Dependence of G-sub-o on Stress State andHist in Cohesive Soils,' Procedings, Int. Symp. on Pre-fadureDeformation of GeomatenuIs, Vol.2, pp.1155-1160
  30. Rocsler, S. K. (1979), 'Anisotropic Shear Modulus due to Strcss Anisotropy,' J. Geotech. Engrg. Div., ASCE, Vol.105, No.GT7,pp.871-880
  31. Saxena, S. K. and Reddy, K. R. (1989), 'Dynamic Moduli andDamping Ratios for Monterey No. 0 Sand bv Resonant ColumnTests,' Soils and Foundations, JSSMFE, Vo1.29, No.2, pp.37-51
  32. Seed, H. B. and Idriss, I. M. (1970), 'Soil Moduli and DampingFactors for Dynamic Response Analyses,' Report No.EERC 70-10,EERC, Univ. of CA at Berkeley, Califomia
  33. Silver, M. L. and Seed, H. B. (1971), 'Deformation Characteristicsof Sands under Cyclic Loading,' J. SMFD, ASCE, Vol.97, No.SM8, pp.1081-1098
  34. Stokoc, K. H., II, Anderson, D. G., Hoar, R. J., and Isenhower,W. M. (1978), 'Insitu and Laboratory Shear Velocity and Modulus,'Proceedings. Earthquake Ensre and SoiI Dynamics, Pasadena,CA., ASCE, Vol.III, pp.1498-1502
  35. Tatsuoka, F., Iwasaki, T., and Takagi, Y. (1978), 'HystereticDamping of Sands under Cyclic Loading and Its Relation to ShearModulus,' Soils and Foundations, JSSMFE, Vol.18, No.2, pp.25-40
  36. Tatsuoka, F., Iwasaki, T., Yoshida, S., Fukushima, S., and Sudo,H (1979), 'Shear Modulus and Damping by Drained Tests onClean Sand Specimens Reconstituted by Various Methods,' Soilsand Foundations, JSSMFE, Vol.19, No.1, pp.39-54
  37. Thiers, G. R. and Seed, H. B. (1968), 'Cyclic Stress-StrainCharacteristics of Clay,' J. SMFD, ASCE, Vol.94, No.SM2, pp.555-569
  38. Vucetic, M. and Dobry, R. (1991), 'Effect of Soil Plasticity onCyclic Response,' J. Geotech Engrg., ASCE, Vol.117, No.1, pp.89-107
  39. Yamash S. and Toki, S. (1994), 'Cyclic Deformation Characteristicsof Sands in Triaxial and Torsional Tests,' Proceedines, Int. Svmpon Pre-failure Deformation of Geomateriats, Vol.1, pp.31-36
  40. Yasuda, N. and Matsumoto, N. (1993), 'Dynamic DeformationCharacteristics of Sands and Rockfill Materials,' Can Geotech. I.,Vol.30, No.5, pp.747-757
  41. Yu, S. and Dakoulas, P. (1993), 'General Stress-Dependent ElasticModuli for Cross-Anisotropic Soils,' J. Geotech Engrg., ASCE, Vol.119, No.10, pp.1568-1586