Investigation of Shear Strength Behavior of Clayey Crushed Stone and Clayey Natural Gravel with Large Scale Direct Shear Tests

Öz

Soils, classified according to their grain sizes, are generally in a mixture in various proportions in the nature. In this study, shear strength properties of clayey gravel samples which prepared in three different compositions were investigated with large scale direct shear tests. In order to investigate soil type, particle size, shape and roughness effects on shear strength properties, samples containing various grain sized gravel and kaoline clay were prepared and experiments were conducted in saturated condition. The results have shown that, crushed stone sample containing bigger grain size had 10% bigger internal friction angle than sample in same composition. It was observed that, crushed stone had 16% bigger internal friction angle than gravel sample prepared in same composition and grain sized.

Anahtar Kelimeler

• Large scale direct shear, Gravel, Shear strength, Crushed stone, Kaoline

Killi Kırmataş ve Killi Doğal Çakılların Kayma Mukavemeti Davranışlarının Büyük Ölçekli Direk Kesme Deneyleriyle İncelemesi

Öz

Belirli dane boyutlarına göre sınıflandırılan zeminler doğada genellikle çeşitli oranlarda karışım halinde bulunmaktadır. Bu çalışma kapsamında 3 farklı kompozisyonda hazırlanmış kil - çakıl numunelerinin kayma mukavemeti özellikleri büyük ölçekli direk kesme deneyleriyle incelenmiştir. Çakıl türünün, dane boyutunun, şeklinin ve pürüzlülüğünün kayma mukavemeti üzerindeki etkisinin incelenmesi amacıyla çeşitli dane dağılımına sahip kırmataş ve dere çakılları kaolin kiliyle belirli kompozisyonlarda karıştırılarak numuneler hazırlanmış, doygun durumda deneyleri yapılmıştır. Deneyler neticesinde kırmataş içeren aynı kompozisyondaki iki numuneden, iri dane dağılımlı numunenin %10 oranında daha büyük içsel sürtünme açısına sahip olduğu belirlenmiştir. Aynı kompozisyon ve dane dağılımına sahip iki numuneden kırmataş içeren numunenin, dere çakılı içeren numuneden %16 daha büyük içsel sürtünme açısına sahip olduğu belirlenmiştir

Anahtar Kelimeler

• Büyük ölçekli direk kesme, Çakıl, Kayma dayanımı, Kırmataş, Kaolin

Kaynakça

1. Miller, E.A., Sowers, G.F. 1957. The Strength Characteristics of Soil- Aggregate Research Board Bull., Cilt. 183, s. 16-23. Highway
2. Holtz, W.G., Ellis, W. 1961. Triaxial Shear Characteristics of Clayey Gravel Soils, Proc. of the 5th Intern. Conf. on Soil Mech. and Found. Eng., Paris, Cilt. 1, s. 143.
3. Leps, T.M. 1970. Review of Shearing Strength of Rockfill, Journal of the Soil Mechanics and Foundation Division, Am. Soc. Of Civil Eng., Cilt. 96, No. SM4, Proc. Paper 7394, July, s. 1159-1170.
4. Vallejo, L.E., Zhou, Y. 1994. The Mechanical Properties of Simulated Soil-Rock Mixtures, Proc. of the 13th Intern. Conf. on Soil Mech. and Found. Eng., New Delhi, India, Cilt. 1, January 10, s. 365-368.
5. Yagiz S. 2001. Brief note on the influence of shape and percentage of gravel on the shear strength of sand and gravel mixtures, Bull. Eng. Geol. Environ., Cilt. 60, s. 321-323.
6. Li, Y.R., Huang, R.Q., Chan, L.S., Chen, J. 2013. Effects of particle shape on shear strength of clay- gravel mixture. J. Civil. Eng. KSCE, Cilt. 17(4), s. 712–717.
7. Monkul, M.M., Ozden, G. 2007. Compressional behavior of clayey sand and transition fines content, Engineering 89(3-4), 195-205. (Ranked as 22nd in the Science Direct’s Top 25 Hottest Articles list in Engineering Geology for Jan-March 2007).
8. Iannacchione, A.T., Vallejo, L.E. 1995. Factors Affecting the Slope Stability of Kentucky’s Abondoned Mine Lands, Proc. Of the 35th U.S. Symp. On Rock Mech., Tahoe, NV, June 5-7, s. 837-842.

9. Iannacchione AT, Bhatt SK, Sefton J. 1994. Geotechnical Properties of Kentucky’s AML Landslides and Slope Failure Evaluation, Proc. Of the Assoc. Of Aband. Land Progr, 16th Ann. Conf. Reclaiming for the Future, Park City, UT, Sept. 18-22, s.129-145.
10. Rathee, R.K. 1981. Shear Strength of Granular Soils and Its Prediction by Modelling Techniques, Indian Geot. J., Cilt. 5, No 2, s. 98-113.
11. ASTM D854. 2014. Standard Test Methods for Specific Gravity of Soil Solids by Water Pycnometer, ASTM International, West Conshohocken, PA.
12. ASTM D4318. 2005. Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils, ASTM Conshohocken, PA. West for Laboratory Test Method for Swell Index of Clay Mineral Geosynthetic Clay Liners, ASTM International, West Conshohocken, PA. of
13. Sivapullaiah, P.V., Sitharam, T.G., Rao, K.S.S. 1987. Modified free swell index for clays, Geotechnical Testing Journal Cilt. 10(2), s. 80–85.
14. ASTM D6913. 2009. Standard Test Methods Distribution (Gradation) of Soils Using International, West Conshohocken, PA. ASTM
15. ASTM D4253. 2014. Standard Test Methods for Maximum Index Density and Unit Weight of Soils Using a Vibratory Table, ASTM International, West Conshohocken, PA.
16. ASTM D3080. 2011. Standard Test Method for Direct Shear Test of Soils Under Consolidated Drained Conditions, ASTM International, West Conshohocken, PA.