Tekrarlı trafik yükleri altında farklı kil içeriklerine sahip orta-sıkı kum-kil karışımlarının esneklik modülünün incelenmesi

Yıl 2021, Cilt: 10 Sayı: 1, 351 - 357, 15.01.2021

Halil İbrahim Fedakar

https://doi.org/10.28948/ngumuh.829513

Öz

Esneklik modülü, tekrarlı trafik yükleri altında yol temel tabakalarının uzun dönem deformasyon performansının tahmin edilmesinde yaygın olarak kullanılmaktadır. Bu nedenle, bu malzeme özelliğinin doğru tayini yol tasarımlarında büyük öneme sahiptir. Bu çalışmada, orta sıkı kum-kil karışımlarının esneklik modülü, dinamik üç eksenli ve kalp şekli gerilme izleri ile araştırılmıştır. Bu amaç doğrultusunda, ağırlıkça %0, %5, %10 ve %20 kil içeren kum-kil numuneleri %50 başlangıç rölatif sıkılıkta hazırlanmış ve yarık silindir deney cihazı kullanılarak test edilmiştir. Deney sonuçlarına göre kum-kil karışımlarının esneklik modülü değerleri dinamik üç eksenli gerilme izi ile daha fazla tahmin edilmektedir. Bu durum ise orta-sıkı kum-kil karışımlarının trafik yükleri altındaki deformasyon davranışının kalp şekli gerilme izine kıyasla daha düşük tahmin edilmesine sebep olmaktadır. Bu çalışmanın bulgularına dayanarak, kum-kil karışımlarının esneklik modülünün yol tasarımları için daha doğru bir şekilde tahmin edilmesinde kalp şekli gerilme izinin göz önüne alınması gerektiği sonucuna varılmıştır.

Anahtar Kelimeler

Esneklik modülü, Kum-kil karışımı, Kalp şekli gerilme izi, Dinamik üç eksenli gerilme izi

Teşekkür

Bu çalışma, TÜBİTAK yurt dışı doktora sonrası araştırma bursu (2219) ile Iowa Eyalet Üniversitesi İnşaat, Yapı ve Çevre Mühendisliği Bölümü laboratuvarlarında Dr. Cassandra Rutherford ve Doç. Dr. Bora Çetin’in bilgileri dahilinde gerçekleştirilmiştir.

Investigation of resilient modulus of medium-dense sand-clay mixtures with different clay contents under repeated traffic loads

Öz

Resilient modulus is commonly used in prediction of long-term deformation performances of pavement foundation layers under repeated traffic loads. For this reason, the determination of this material property accurately has a great importance in pavement designs. In this study, resilient modulus of medium-dense sand-clay mixtures was investigated through cyclic triaxial and heart-shaped stress paths. For this purpose, sand-clay specimens having a clay content as 0%, 5%, 10%, and 20% by weight were prepared at an initial relative density of 50% and tested using hollow cylinder testing apparatus. According to the test results, the resilient modulus values of sand-clay mixtures are overestimated by cyclic triaxial stress path, which results in the underestimation of deformation behavior of medium-dense sand-clay mixtures under traffic loads compared to heart-shaped stress path. Based on the findings of this study, it is concluded that a heart-shaped stress path should be taken into consideration for a more accurate prediction of resilient modulus of sand-clay mixtures for pavement designs.

Anahtar Kelimeler

Resilient modulus, Sand-clay mixture, Heart-shaped stress path, Cyclic triaxial stress path

Kaynakça

• Md. Jibon, D. Mishra and E. Kassem, Laboratory characterization of fine-grained soils for Pavement ME Design implementation in Idaho. Transportation Geotechnics, 25, 100395, 2020. https://doi.org/ 10.1016/j.trgeo.2020.100395.
• G. Ma, H. Li, B. Yang, H. Zhang and W. Li, Investigation on the deformation behavior of open-graded unbound granular materials for permeable pavement. Construction and Building Materials, 260, 119800, 2020. https://doi.org/10.1016/j.conbuildmat. 2020.119800.
• L. Guo, Y. Cai, R. J. Jardine, Z. Yang and J. Wang, Undrained behaviour of intact soft clay under cyclic paths that match vehicle loading conditions, Canadian Geotechnical Journal, 55, 90–106, 2018. https://doi.org/10.1139/cgj-2016-0636.
• A. Cetin, Z. Kaya, B. Cetin and A. H. Aydilek, Influence of laboratory compaction method on mechanical and hydraulic characteristics of unbound granular base materials. Road Materials and Pavement Design, 15 (1), 220-235, 2014. https://doi.org/10.1080/ 14680629.2013.869505.
• I. Haider, Z. Kaya, A. Cetin, M. Hatipoglu, B. Cetin and A. H. Aydilek, Drainage and mechanical behavior of highway base materials. Journal of Irrigation and Drainage Engineering, 140 (6), 04014012, 2014. https://doi.org/10.1061/(ASCE)IR.19434774.0000708.
• S. H. He, Z. Ding, T.D. Xia, W. H. Zhou, X. L. Gan, Y. Z. Chen and F. Xia, Long-term behaviour and degradation of calcareous sand under cyclic loading. Engineering Geology, 276, 105756, 2020. https://doi.org/10.1016/j.enggeo.2020.105756.
• N. Venkatesh, M. Heeralal and R. J. Pillai, Resilient and permanent deformation behaviour of clayey subgrade soil subjected to repeated load triaxial tests. European Journal of Environmental and Civil Engineering, 24 (9), 1414-1429, 2020. https://doi.org/ 10.1080/ 19648189.2018.1472041.
• Y. Cai, Q. Sun, L. Guo, C. H. Juang and J. Wang, Permanent deformation characteristics of saturated sand under cyclic loading. Canadian Geotechnical Journal, 52, 795-807, 2015. https://doi.org/10.1139 /cgj-2014-0341.
• L. Guo, J. Chen, J. Wang, Y. Cai and P. Deng, Influences of stress magnitude and loading frequency on cyclic behavior of K0-consolidated marine clay involving principal stress rotation. Soil Dynamics and Earthquake Engineering, 84, 94-107, 2016. http://doi.org/10.1016/j.soildyn.2016.01.024.
• J. G. Qian, Y. G. Wang, Z. Y. Yin and M. S. Huang, Experimental identification of plastic shakedown behavior of saturated clay subjected to traffic loading with principal stress rotation. Engineering Geology, 214, 29-42, 2016. http://dx.doi.org/10.1016/ j.enggeo.2016.09.012.
• Y. Q. Cai, L. Guo, R. J. Jardine, Z. X. Yang and J. Wang, Stress-strain response of soft clay to traffic loading. Géotechnique, 67(5), 446-451, 2017. https://doi.org/ 10.1680/jgeot.15.P.224.
• H. I. Fedakar, W. Cai, C. J. Rutherford and B. Cetin, Evaluation of deformation behavior of sand-clay mixture under traffic loads. Geo-Congress 2020, ASCE Geotechnical Special Publications (GSP 317), sayfa 201-209, Minneapolis, Minnesota, ABD, 25-28 Şubat 2020.
• Y. Cai, T. Wu, L. Guo and J. Wang, Stiffness degradation and plastic strain accumulation of clay under cyclic load with principal stress rotation and deviatoric stress variation. Journal of Geotechnical and Geoenvironmental Engineering, 144 (5), 04018021, 2018. https://doi.org/10.1061/(asce)gt.1943-5606. 0001854.
• Q. Yang, Y. Tang, B. Yuan and J. Zhou, Cyclic stress-strain behaviour of soft clay under traffic loading through hollow cylinder apparatus: effect of loading frequency. Road Materials and Pavement Design, 20 (5), 1026-1058, 2019. https://doi.org/10.1080/ 14680629.2018.1428219.
• D. C. Simpson and T. M. Evans, Behavioral thresholds in mixtures of sand and kaolinite clay. Journal of Geotechnical and Geoenvironmental Engineering, 142 (2), 04015073, 2016. https://doi.org/10.1061/ (ASCE)GT.1943-5606.0001391.
• H. Choo, W. Lee and C. Lee, Compressibility and small strain stiffness of kaolin clay mixed with varying amounts of sand. KSCE Journal of Civil Engineering, 21 (6), 2152-2161, 2017. https://doi.org/10.1007/ s12205-016-1787-4.
• M. Cubrinovski and S. Rees, Effects of fines on undrained behaviour of sands. Geotechnical Earthquake Engineering and Soil Dynamics IV, ASCE Geotechnical Special Publications (GSP 181), sayfa 1-11, Sacramento, California, ABD, 18-22 Mayıs 2008.
• P. V. Lade, C. D. Liggio and J. A. Yamamuro, Effects of non-plastic fines on minimum and maximum void ratios of sand. ASTM Geotechnical Testing Journal, 21 (4), 336-347, 1998. https://doi.org/10.1520/ GTJ11373J.
• A. Miftah, A. H. B. Garoushi and H. Bilsel, Effects of fine content on undrained shear response of sand-clay mixture. International Journal of Geosynthetics and Ground Engineering, 6 (10), 2020. https://doi.org/ 10.1007/s40891-020-0193-7.
• B. M. Das, Principles of Geotechnical Engineering. Cengage Learning, CT, ABD, 2010.
• C. Chazallon, P. Hornych and S. Mouhoubi, Elastoplastic model fort he long-term behavior modeling of unbound granular materials in flexible pavements. International Journal of Geomechanics, 6 (4), 279-289, 2006. https://doi.org/10.1061/(asce) 1532-3641(2006)6:4(279).