Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
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Shear Strength Estimation of Clean Sands via Shear Wave Velocity

전단파 속도를 통한 모래의 전단강도 예측

  • Yoo, Jin-Kwon (Dept. of Civil and Environmental Engrg., Hanyang Univ.) ;
  • Park, Duhee (Dept. of Civil and Environmental Engrg., Hanyang Univ.)
  • 유진권 (한양대학교 건설환경공학과) ;
  • 박두희 (한양대학교 건설환경공학과)
  • Received : 2015.04.14
  • Accepted : 2015.08.27
  • Published : 2015.09.30
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Abstract

We perform a series of experimental tests to evaluate whether the shear strength of clean sands can be reliably predicted from shear wave velocity. Isotropic drained triaxial tests on clean sands reconstituted at different relative densities are performed to measure the shear strength and bender elements are used to measure the shear wave velocity. Laboratory tests reveal that a correlation between shear wave velocity, void ratio, and confining pressure can be made. The correlation can be used to determine the void ratio from measured shear wave velocity, from which the shear strength is predicted. We also show that a unique relationship exists between maximum shear modulus and effective axial stress at failure. The accuracy of the equation can be enhanced by including the normalized confining pressure in the equation. Comparisons between measured and predicted effective friction angle demonstrate that the proposed equation can accurately predict the internal friction angle of granular soils, accounting for the effect of the relative density, from shear wave velocity.

벤더엘리먼트가 장착된 삼축압축시험장비를 이용하여 모래에 대한 일련의 압밀배수시험을 수행하였다. 상대밀도 및 유효구속응력 조건을 달리하여 각각의 조건별 응력-변형률 관계를 측정하였으며, 압밀이 종료된 시점에서의 전단파 속도를 측정함으로써 전단파 속도와 간극비, 유효응력, 그리고 전단강도와의 상관관계를 분석하였다. 분석 결과, 미소변형률에서의 전단파 속도로부터 계산된 최대전단탄성계수와 파괴 시의 축응력과 압밀 시의 구속응력의 합으로 정의되는 유효수직응력간에는 고유한 상관관계가 존재하는 것으로 나타났다. 도출된 전단탄성계수와 유효수직응력간의 상관관계는 유효구속응력을 정규화시킴으로써 정확도를 향상시켰다. 본 연구를 통해 제시된 상관관계를 통해 전단강도 및 내부 마찰각을 예측하였을 시, 실제 실내 시험을 통해 산출된 내부 마찰각을 정확하게 예측할 수 있는 것으로 나타났다. 이는 미소변형률에서의 전단파 속도를 기반으로 신뢰성 높은 파괴 시 전단강도, 나아가 내부 마찰각까지 예측이 가능하다는 것을 의미하며 기존 SPT-N value와 경험식을 통해 내부 마찰각을 예측하여 설계에 적용하는 방식의 불확실성을 개선해 줄 수 있는 매우 유용한 방법이라고 판단된다.

Keywords

References

  1. ASTM D7181 (2011), "Standard Test Method for Consolidated Drained Triaxial Compression Test for Soils", West Conshohocken, PA: ASTM International.
  2. Bolton, M.D. (1986), "The Strength and Dilatancy of Sands", Geotechnique, Vol.36, No.1, pp.65-78. https://doi.org/10.1680/geot.1986.36.1.65
  3. Bryan, G. and Stoll, R. (1988), "The Dynamic Shear Modulus of Marine Sediments", The Journal of the Acoustical Society of America, Vol.83, No.6, pp.2159-2164. https://doi.org/10.1121/1.396343
  4. Cha, M. and Cho, G.-C. (2007), "Shear Strength Estimation of Sandy Soils Using Shear Wave Velocity", ASTM geotechnical testing journal, Vol.30, No.6, pp.484-495.
  5. Chiang, Y.-C. and Chae, Y.S. (1972), Dynamic properties of cementtreated soils, Hwy. Res. Rec., Washington, D.C.
  6. Cresswell, A., Barton, M.E., and Brown, R. (1999), "Determining the Maximum Density of Sands by Pluviation", ASTM geotechnical testing journal, Vol.22, No.4, pp.324-328. https://doi.org/10.1520/GTJ11245J
  7. Cunning, J., Robertson, P., and Sego, D. (1995), "Shear Wave Velocity to Evaluate in Situ State of Cohesionless Soils", Canadian Geotechnical Journal, Vol.32, No.5, pp.848-858. https://doi.org/10.1139/t95-081
  8. Frost, J. and Park, J.-Y. (2003), "A Critical Assessment of the Moist Tamping Technique", ASTM geotechnical testing journal, Vol.26, No.1, pp.57-70.
  9. Guadalupe, Y., Baxter, C.D., and Sharma, M.S.R. (2013), "Measuring Shear Wave Velocity in Laboratory to Link Small-and Large-Strain Behavior of Soils", Transportation Research Record: Journal of the Transportation Research Board, Vol.2335, No.1, pp.79-88. https://doi.org/10.3141/2335-09
  10. Hardin, B. and Richart, J., FE (1963), "Elastic Wave Velocities in Granular Soils", Journal of Soil Mechanics & Foundations Div, Vol.89, No.Proc. Paper 3407.
  11. Hardin, B.O. and Drnevich, V.P. (1972), "Shear Modulus and Damping in Soils: Measurement and Parameter Effects", Journal of Soil Mechanics and Foundation Engineering Division, Vol.98, No.SM6, pp.603-624.
  12. Ladd, C.C. and Foott, R. (1974), "New Design Procedure for Stability of Soft Clays", Journal of the Geotechnical Engineering Division, Vol.100, No.Gt7, pp.763-786.
  13. Ladd, R. (1978), "Preparing Test Specimens Using Undercompaction", ASTM geotechnical testing journal, Vol.1, No.1, pp.16-23. https://doi.org/10.1520/GTJ10364J
  14. Lee, J.-S. and Santamarina, J.C. (2005), "Bender Elements: Performance and Signal Interpretation", Journal of geotechnical and geoenvironmental engineering, Vol.131, No.9, pp.1063-1070. https://doi.org/10.1061/(ASCE)1090-0241(2005)131:9(1063)
  15. Lee, J.-S. and Yoon, H.-K. (2014), "Porosity Estimation Based on Seismic Wave Velocity at Shallow Depths", Journal of Applied Geophysics, Vol.105, pp.185-190. https://doi.org/10.1016/j.jappgeo.2014.03.018
  16. Richart Jr, F., Hall Jr, J., and Woods, R. (1970), "Vibration of Soils and Foundations": Prentice-Hall, Englewood Cliffs, New Jersey.
  17. Robertson, P., Sasitharan, S., Cunning, J., and Sego, D. (1995), "Shear-wave Velocity to Evaluate in-situ State of Ottawa Sand", Journal of Geotechnical Engineering, Vol.121, No.3, pp.262-273. https://doi.org/10.1061/(ASCE)0733-9410(1995)121:3(262)
  18. Roesler, S.K. (1979), "Anisotropic Shear Modulus due to Stress Anisotropy", Journal of the Geotechnical Engineering Division, Vol.105, No.7, pp.871-880.
  19. Santamarina, J.C., Klein, A., and Fam, M.A. (2001), "Soils and Waves: Particulate Materials behavior, Characterization and Process Monitoring", Journal of Soils and Sediments, Vol.1, No.2, pp.257.
  20. Saxena, S.K., Avramidis, A.S., and Reddy, K.R. (1988), "Dynamic Moduli and Damping Ratios for Cemented Sands at Low Strains", Canadian Geotechnical Journal, Vol.25, No.2, pp.353-368. https://doi.org/10.1139/t88-036
  21. Sharma, R., Baxter, C., and Jander, M. (2011), "Relationship between Shear Wave Velocity and Stresses at Failure for Weakly Cemented Sands during Drained Triaxial Compression", Soils and foundations, Vol.51, No.4, pp.761. https://doi.org/10.3208/sandf.51.761
  22. Skempton, A. (1954), "The Pore-pressure Coefficients A and B", Geotechnique, Vol.4, No.4, pp.143-147. https://doi.org/10.1680/geot.1954.4.4.143
  23. Vaid, Y. and Negussey, D. (1988), "Preparation of Reconstituted Sand Specimens", Advanced triaxial testing of soil and rock, ASTM STP, Vol.977, pp.405-417.
  24. Yoo, J.-K. and Park, D. (2014), "Evaluation of Characteristics of Shear Strength and Poisson's Ratiothrough Triaxial and Bender Element Tests", Journal of the Korean Geotechnical Society, Vol. 30, No.5, pp.67-75. https://doi.org/10.7843/KGS.2014.30.5.67
  25. Yoon, H.-K. and Lee, J.-S. (2010), "Field Velocity Resistivity Probe for Estimating Stiffness and Void Ratio", Soil Dynamics and Earthquake Engineering, Vol.30, No.12, pp.1540-1549. https://doi.org/10.1016/j.soildyn.2010.07.008
  26. Yoshimi, Y., Tokimatsu, J., and Ohara, A. (1994), "In Situ Liquefaction Resistance of Clean Sands Over a Wide Density Range", Geotechnique, Vol.44, No.3, pp.479-494. https://doi.org/10.1680/geot.1994.44.3.479