Effect of Average and Cyclic Shear Stress on Undrained Cyclic Behavior of Marine Silty Sand

Safdar Muhammad; Su-Won Son; Jin-Man Kim

doi:10.7843/kgs.2014.30.1.17

All Issue

2014 Vol.30, Issue 1 Preview Page Next Page

Effect of Average and Cyclic Shear Stress on Undrained Cyclic Behavior of Marine Silty Sand 해양 실트질 모래의 비배수 동적 거동에 대한 평균 및 반복전단응력의 영향

31 January 2014. pp. 17-25

PDF XML

Abstract

Offshore wind turbine foundations are subjected to wind, current and wave loadings. Hence, both static and cyclic behaviors of foundation’s soil are important for the design of offshore wind turbine foundation. Undrained cyclic behaviors of soils depend upon the number of loading cycles, vertical effective stress, cyclic shear strain, relative density, and the combination of cyclic and average shear stresses. In order to evaluate the effect of average and cyclic shear stresses on the undrained cyclic behavior of marine silty sand, cyclic direct simple shear (CDSS) tests are performed with relative density of 85%, vertical effective stress of 200 and 300 kPa, and failure criteria of either 15% double amplitude cyclic shear strain (γcyc) or permanent shear strain (γp). The results are presented in the form of design graphs or contour diagrams. The undrained cyclic behavior of marine silty sand is found to be dependent on cyclic and average shear stresses and/or the combination of both shear stresses. It is found that when significant average shear stress exists the permanent or progressive shear strain is the govering failure criteria instead of cyclic shear strain.

Keywords

Cyclic Direct Simple Shear (CDSS)

Undrained cyclic behavior

Average and cyclic shear stress

Relative density

Marine silty sand

해상풍력발전기의 기초는 바람, 조류, 그리고 파도 하중을 받기 때문에 해상풍력발전기 기초를 설계하는 데 있어 반복하중을 받는 기초지반의 전단거동 평가가 필요하다. 지반의 비배수 동적 전단거동은 반복하중 횟수, 수직 유효응력, 반복 전단변형률, 상대 밀도, 그리고 평균 및 반복전단응력의 조합에 영향을 받는다. 본 연구에서는 해양 실트질 모래의 비배수 동적 거동에 대한 평균 및 반복전단응력의 영향을 평가하기 위하여 반복단순전단시험(CDSS)을 수행하였으며 상대밀도 85%, 수직 유효응력 200kPa과 300kPa의 시험조건에서 15%의 이중진폭 동적전단변형률(γcyc)과 영구전단변형률(γp)를 파괴 기준으로 적용하였다. 시험결과는 설계 그래프와 등고선도로 나타내었다. 결과에 따르면 해양 실트질 모래의 비배수 동적 거동은 평균 및 반복전단응력과 두가지 전단응력의 조합에 의해 크게 변하는 경향을 보였다. 평균전단응력이 존재하는 경우에는 반복전단변형보다는 영구변형에 의해 파괴가 결정되는 것으로 나타났다.

References

1.Andersen, K. H., Kleven, A., and Heien, D. (1988), “Cyclic soil data for design of gravity structures”, Journal of Geotechnical Engineering, Vol.114, No.5, pp.517-539.

2.Andersen, K. H. and Berre, T. (1999), “Behavior of a dense sand under monotonic and cyclic loading”, In Proceedings of the 12th ECSMGE, Geotechnical Engineering for Transportation Infrastructure, Amsterdam, the Netherlands, 7-10 June 1999.

3.Andresen, L. and Jostad, H.P. (2004), “Analyses of progressive failure in long natural slopes”, In Numerical Models in Geomechanics: Proceedings of NUMOG IX, Ottawa, Ont., 25-27 August2004. Edited by G.N. Pande and S. Pietruszczak. Taylor & Francis Group, London. pp. 603-608.

4.Andersen, K. H. (2009), “Bearing capacity under cyclic loading, offshore, along the coast and on land. The 21st Bjerrum Lecture presented in Oslo, 23 November 2007”, Canadian Geotechnical Journal, Vol.46, No.5, pp.513-535

5.Baxter, C. D. P., Bradshaw, A. S., Ochoa-Lavergne, M., and Hankour, R. (2010), “DSS Test Results using Wire-Reinforced Membranes and Stacked Rings”. GeoFlorida 2010 ASCE.

6.Bjerrum, L. and Landva, A. (1966), “Direct-Simple Shear Tests on a Norwegian Quick Clay”, Geotechnique, Vol.16, No.1, pp.1-20

7.Catro, G. (1969), Liquefaction of sands, Ph.D Thesis, Harvard University, Cambridge, Mass.

8.Dyvik, R., Berre, T., Lacasse, S., and Raadim, B. (1987), “Comparison of truly undrained and constant volume direct simple shear tests”, Geotechnique, Vol.37, No.1, pp.3-10.

9.Goulois, A. M., Whitman, R. W., and Høeg, K. (1985), “Effects of sustained shear stresses on the cyclic degradation of clay”, ASTM Special technical publication, 883, pp.330-351.

10.Kuerbis, R. and Vaid, Y. P. (1988), “Sand Sample Preparation- Slurry Deposition Method”, Soils and Foundations, Vol.28 No.4, pp.107-118.

11.Kuerbis, R. and Vaid, Y. P. (1988), “Sand Sample Preparation- Slurry Deposition Method”, Soils and Foundations, Vol.28, No.4, pp.107-118.

12.Lambe, W. T. (1951), “Soil Testing for Engineers” John Wiley and Sons Inc, New York.

13.Lee, K. and Seed, H. B. (1967), “Dynamic strength of anisotropically consolidated sand”, Journal of Soil Mechanics and Foundation Division, ASCE, pp.169-190

14.Miura, S. and Toki, S. (1982), “A sample preparation method and it effect on static and cyclic deformation-strength properties of sand”, Soils and Foundation, Vol.22, No.1, pp.61-77

15.Mulilus, J. P., Seed, H. B., Chan, C. K., Mitchell, J. K., and Arulanandan, K. (1977), “Effects of sample preparation on sample preparation”, Journal of Getechnical Engineering Division, ASCE 103 (GT2), pp.99-108.

16.Nielsen, S. K., Amir Shajarati, K.W., Sorenson, L. B., Ibsen (2012), “Behavior of Dense Frederikshavn sand during cyclic Loading”, DCE Technical Memorandum, No.15, pp.1-9

17.Randolph, M. F. and Gouvernec, S. (2011), Offshore Geotechnical Enigineering, Spon Press, UK.

18.Safdar, M. and Kim, J.M. (2013), “Cyclic behavior of marine silty sand”, Electronic Journal of Geotechnical Engineering (EJGE). Vol.18, Pages 209-218

19.Vaid, Y.P. and Negussey, D. (1984), “Relative density of air and water pluviated sand”, Soils and Foundations, Vol.24 No.2, pp. 101-105.

20.Vaid, Y.P., and Negussey, D. (1988), “Preparation of reconstituted sand specimens”, ASTM STP 977.

Information

Publisher :The Korean Geotechnical Society
Publisher(Ko) :한국지반공학회
Journal Title :Journal of the Korean Geotechnical Society
Journal Title(Ko) :한국지반공학회 논문집
Volume : 30
No :1
Pages :17-25
Received Date : 2013-06-02
Revised Date : 2014-01-14
Accepted Date : 2014-01-22
DOI :https://doi.org/10.7843/kgs.2014.30.1.17

Journal of the Korean Geotechnical Society ISSN:1229-2427(Print) 2288-646X(Online) 한국지반공학회 논문집

All Issue