AN APROACH FOR CYCLIC STRESS RATIO OF LIQUEFIED OR UNLIQUEFIED SOILS

Öz

In this paper an alternative analytical relationship is developed that adds soil shear wave velocities (Vs) and earthquake dominating period (T) to an earthquake and soil parameters used in the determination of cyclic loads. This relation is named as shear stress ratio (KGO). KGO is applied to 202 field data and the results are compared in accordance with the results of mathematical relation (CSR) used before. Consequently, KGO value for liquefied soil is bigger than CSR. Whereas, KGO value of unliquefied soils is smaller than CSR. A linear relation is determined between KGO and CSR

Anahtar Kelimeler

• Shear wave velocity, Cyclic stress ratio, Water-saturated soils, Liquefied soil, Unliquefied soil

SIVILAŞIR YADA SIVILAŞMAZ ZEMİNLERİN YİNELEMELİ GERİLME ORANINA BİR SEÇENEK

Öz

Bu çalışmada, yinelemeli (tekrarlı) yüklerin belirlenmesi için kullanılan deprem ile zemin parametrelerine, zeminin kayma dalga hızları (Vs) ve deprem dalgasının hakim periyodu da (T) eklenerek alternatif bir analitik ilişki geliştirilmiş ve kayma gerilme oranı (KGO) olarak isimlendirilmiştir. KGO 202 adet alan verisi üzerinde uygulanmış ve sonuçların daha önce kullanılan matematiksel bağıntının (CSR) sonuçlarıyla karşılaştırılmıştır. Sonuç olarak sıvılaşan zeminlerde hesaplanan yinelemeli gerilme oran değerlerinden KGO, CSR’den daha büyük, sıvılaşmayan zeminlerde ise daha küçük olduğu görülmüştür. Ayrıca KGO ile CSR arasında doğrusal bir ilişki belirlenmiştir

Anahtar Kelimeler

• Kayma dalga hızı, Yinelemeli gerilme oranı, Suya doygun zemin, Sıvılaşır zemin, Sıvılaşmaz zemin

Kaynakça

1. Andrus R.D., Stokoe K.H. (2000): “Liquefaction Resistance of Soils from Shear-Wave Velocity”, Journal of Geotechnical and Geoenvironmental Engineering, (ASCE) 126, pp. 1015-1025.
2. Gardner G.H.F., Gardner L.W., Gregory A.R. (1974): “Formation Velocity and Density the Diagnastic Basics for Stractigraphic Traps”, Geophysics, 39, pp. 770-780.
3. Hardin B.O., Drenevich V.P. (1972): “Shear Modulus and Damping in Soils: Desing Equations and Curves”, Journal of the Soil Mechanics and Foundations Division (ASCE) 98, pp. 667-692.
4. Ishihara K. (1996): “Soil Behaviour in Earthquake Geotechnics”, Clarendan Press, Oxford p. 350.
5. Liao S.S.C., Whitman R.V. (1986): “Overburden Correction Factors for SPT in Sands”, Journal of Geotechnical Engineering (ASCE), 112, pp. 373-337.
6. Nazarin S., Stokoe K.H. (1984): “In Situ Shear Wave Velocity from Spectral Analysis of Surface Waves”, Proceedings of the 8th World Conference on Earthquake Engineering, San Francisco, Vol. III, pp. 31-38.
7. Robertson P.K., Woeller D.J., Finn W.D.L. (1992): “Seismic Cone Penetration Test for Evaluating Liquefaction Potential Under Cyclic Loading”, Canadian Geotechnical Journal, Ottawa 29, pp. 686-695.
8. Robertson P.K., Wride C.E. (1997): “Cyclic Liquefaction and Evaluation Based on the SPT and CPT, NCEER Workshop on Evaluation of Liquefaction Resistance of Soils”, Technical Report NCEER-97-0022 (Eds. Youd, T.L. and Idriss, I.M.) Buffalo, NY, 41-87.

9. Roesler S.K. (1979): “Anisotropic Shear Modulus due to Stress Anisotropy”, Journal Geotechnical Engineering Division (ASCE), 105(7), pp. 871-880.
10. Seed H.B., Idriss I.M. (1971): “Simplified Procedure for Evaluating Soil Liquefaction Potential”, Journal of the Soil Mechanics and Foundations Division (ASCE) 97, pp. 1249- 1273.
11. Seed H.B., Idriss I.M., Kiefer F.W. (1969): “Characteristics of Rock Motion During Earthquakes”, Journal of the Soil Mechanics and Foundations Division (ASCE) 9 (SMS).
12. Stokoe K.H.II, Lee S.H.H., Knox D.P. (1985): “Shear Module Measurements Under True Triaxial Stresses”, Proceedings, Advancers in the Art of Testing Soil Under Cyclic Conditions (ASCE), 166-185.
13. Stokoe K.H., Nazarin S. (1983): “Effectiveness of Ground Improvement from Spectral Analysis of Surface Waves”, Proceedings of the 8th European Conference on Soil Mechanics and Foundation Engineering, Helsinki, pp. 91-4.
14. Stokoe K.H., Wright S.G., Bay J.A., Roesset J.M. (1994): “Characterization of Geotechnical Sites by SASW Method”, Geotechnical Characterization of Site, Special volume of ISSMFE TC10, New Delhi.
15. Sykora D.W. (1987b): “Cretation of a Data Base of Seismic Shear Wave Velocities for Correlation Analysis”, Geotechnical Laboratory Miscellaneous, Paper GL 87-26.
16. Tabban A., Gencoğlu S. (1975): “Deprem ve Parametreleri”, Deprem Araştırma Enstitüsü Bülteni, 11.
17. Terzaghi K., Peck R.B. (1948): “Soil Mechanics in Engineering Practice”, John Wiley and Sons, New York, p.566.
18. Uyanık O. (2002): “Kayma Dalga Hızına Bağlı Potansiyel Sıvılaşma Analiz Yöntemi”, DEU. Fen Bilimleri Enstitüsü (Doktora Tezi), s.190, İzmir (yayınlanmamıştır).