Kum Zemine Oturan Model Yüzeysel Temelin Yük-Oturma Davranışının Deneysel ve Nümerik Olarak İncelenmesi

Öz

Teknolojinin gelişmesi insanoğluna daha geniş, daha ağır ve daha karmaşık yapılar inşa etme fırsatı vermiştir. Artan ve karmaşık hale gelen yükleri zemine aktarma problemi ile yüzleşen geoteknik mühendisleri için temellerin yük-oturma davranışını anlamak güvenli temel tasarımı için kaçınılmaz hale gelmiştir. Bu çalışmada yüzeysel temellerin yük-oturma ve taşıma davranışının belirlenmesi amaçlanmıştır. Bu amaçla bir deney düzeneği oluşturulmuş ve farklı rölatif sıkılıklara sahip granüler zemine oturan küçük ölçekli model temeller ile yükleme deneyleri gerçekleştirilmiştir. Ayrıca; fiziksel model testler için deney programına bağlı kalarak sonlu elemanlar yöntemine dayanan ABAQUS/CAE programı ile sayısal analizler yapılmış, elde edilen sonuçların deney sonuçları ile olan uyumu araştırılmıştır. Yapılan çalışmalar sonucunda rölatif sıkılığın, yüzeysel temellerin yük-oturma davranışı üzerinde etkili bir parametre olduğu görülmüştür. Sonuçlar maliyetli ve zaman alıcı saha deneyleri yapmadan kumlu zemine oturan yüzeysel temellerin taşıma ve yük-oturma davranışlarının ön değerlendirmesi için bir referans görevi görebilir.

Anahtar Kelimeler

• Yüzeysel temel
• 1g fiziksel model deney
• nümerik analiz
• yük-oturma davranışı

Experimental and Numerical Investigation of Load-Settlement Behaviour to Model Shallow Foundation rest on Sandy Soil

Öz

Improvement of technology gives the change to humankind to build larger, heavier and more complex structures. For geotechnical engineers, faced with transferring the loads that is more complex and increasing, determination of the load-settlement behaviour has become inevitable for the reliable foundation design. In this study, it is aimed to determinate the bearing and load-settlement behavior of the shallow foundations. For this purpose, a test setup has been formed and loading tests have been carried out by means of small scale model foundation rest on the granular soil with the different relative densities situations. Additionally, numerical analyses, adhering to the experimental program for 1g physical model tests, have been carried out with finite element based software ABAQUS/CAE and the obtained results have been compared with the experimental results. As a result of the study it is shown that the relative density is a very effective parameter for the load-settlement behavior of the shallow foundations. The results can serve as a reference for the preliminary assessment of bearing and load-settlement behavior of shallow foundation in sandy soils without conducting expensive and time-consuming field trials.

Anahtar Kelimeler

• Shallow foundation
• 1g physical model test
• numerical analysis
• load-settlement behavior

Kaynakça

1. ASTM D-854. 2006. “Standard test methods for specific gravity of soil solids by water pycnometer”, ASTM International, West Conshohocken.
2. ASTM D3080M-11. 2011. “Standard test method for direct shear test of soils under consolidated drained conditions”, ASTM International, West Conshohocken.
3. ASTM D4253-16. 2016. “Standard test methods for maximum index density and unit weight of soils using a vibratory table”, ASTM International, West Conshohocken.
4. ASTM D-6913. 2017. “Standard test methods for particle-size distribution (gradation) of soils using sieve analysis”, ASTM International, West Conshohocken.
5. Briaud, J. L. and Jeanjean, P. 1994. “Load settlement curve method for spread footings on sand. Vertical and horizontal deformations of foundations and embankments”, ASCE, 2, 1774-1804.
6. Broms, B. B. 1963. “The effect of degree of saturation on the bearing capacity of flexible pavements”, Highway Research Record, 71, 1–14.
7. Costa, Y. D., Cintra, J. C. and Zornberg, J. G. 2003. “Influence of matric suction on the results of plate load tests performed on a lateritic soil deposit”, Geotech. Testing J., 26(2), 219–226.
8. Debeer, E. E. 1970. “Experimental determination of the shape factors and the bearing capacity factors of sand”, Geotechnique, 20(4), 387-411.

9. Dutte, T. T. and Saride, S. 2015. “Effect of confining pressure, relative density and shear strain on the poisson’s ratio of clean sand”, 50th Indian Geotechnical Conference.
10. Hosseini, A. 2014. “Effect of confinement pressure on bearing capacity of two samples of square and strip footing”, Springer Plus, 3 (1), 1-5.
11. Hossein, R., Nazir, R. and Momeni, E. 2016. “Bearing capacity of thin-walled shallow foundations: an experimental and artificial intelligence-based study”, Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 17 (4), 273-285.
12. Krabbenhoft, S., Clausen, J. and Damkilde, L. 2012. “The bearing capacity of circular footings in sand: comparison between model tests and numerical simulations based on a nonlinear Mohr failure envelope”, Advances in Civil Engineering, 1-10.
13. Meyerhof, G. G. 1951. “The ultimate bearing capacity of foundations”, Géotechnique, 1951, (2), 301– 332.
14. Mohamed, F. M. O. and Vanapalli, S. K. 2006. “Laboratory investigations for the measurement of the bearing capacity of an unsaturated coarse-grained soil”, Proceedings of the 59th Canadian Geotech. Conf., Vancouver, B.C, 219–226.
15. Nguyen, D. D. C., Jo, S. B. and Kim, D. S. 2013. Design method of piled-raft foundations under vertical load considering interaction effects. Computers and Geotechnics, 47, 16-27.
16. Oh, W. T. and Vanapalli, S. K. 2001. “Modeling the stress versus settlement behavior of model footings in saturated and unsaturated sandy soils,” Canadian Geotech. J., 48, 425– 438.
17. Oloo, S. Y., Fredlund, D. G. and Gan, J. K. M. 1997. “Bearing capacity of unpaved roads”, Canadian Geotech. J., 34, 398–407.
18. Schanz, T. and Veermer, P. A. 1996. “Angles of friction and dilatancy of sand”, Geotechnique, 46, 1, 145-151.
19. Terzaghi, K. (1943) “Theoretical Soil Mechanics”, John Wiley and Sons, New York, USA.
20. Trautmann, C. H. and Kulhawy, F. H. 1998. “Uplift load-displacement behavior of spread foundations”, Journal of Geotechnical Engineering, 114, 2, 168-183.
21. Vanapalli, S. K. and Mohamed, F. M. O. 2007. “Bearing capacity of model footings in unsaturated soils”, Springer Proc. in Physics. Springer, 112, 483–493.
22. Vanapalli, S. K. and Mohamed, F. M. O. 2013. “Bearing capacity and settlement of footings in unsaturated sands”, International Journal of GEOMAT, 5 (1), pp. 595-604.