Analysis of the Spacing Effect in 1x2 Configured Group Helical Piles using Laboratory Model Tests

Öz

Helical piles are increasingly popular systems in deep foundation applications. In this study, the effect of the distance between piles and the presence of helices on the load-bearing capacity under pressure in loose sand, within a group of helical piles arranged in a 1x2 configuration, was investigated using laboratory model tests, and the load-displacement curves were interpreted. In the experiments, the helix diameters and numbers were kept constant. The distance between the piles was increased from 200 mm to 700 mm, and load-displacement graphs were obtained for each interval. Piles with helix and without helix were interpreted among themselves while keeping the distance between the piles constant. To find the ultimate failure load from the load-displacement curves obtained from the test results, the %5D and %10D limit displacement criteria were applied. The results showed that the increase in the distance between the piles caused a decrease in load-bearing capacity, while the presence of the helix increased the load-bearing capacity.

Anahtar Kelimeler

• Group Helical Pile
• Bearing Capacity
• Pile Spacing
• Laboratory Tests

1x2 Dizilimli Grup Helisel Kazıklarda Mesafe Etkisinin Laboratuvar Model Deneyleriyle İncelenmesi

Öz

Helisel kazıklar derin temel uygulamalarında popülerliği gittikçe artan sistemlerdir. Bu çalışmada 1x2 diziliminde düzenlenmiş olan helisel kazık grubunda, kazıklar arası mesafenin ve kazıktaki helis varlığının, gevşek kum zeminde, basınç etkisi altında taşıma gücüne etkisi laboratuvar model deneyleri kullanılarak incelenmiş ve yük-deplasman eğrileri yorumlanmıştır. Deneylerde helis çapları ve sayısı sabit tutulmuştur. Kazıklar arası mesafe 200 mm’den 700 mm’ye kadar arttırılmış ve her aralık için yük deplasman grafikleri elde edilmiştir. Helisli ve helissiz kazıklar, kazıklar arası mesafe sabit tutularak kendi aralarında yorumlanmıştır. Deney sonuçlarından elde edilen yük-deplasman eğrilerinin nihai göçme yükünü bulmak için %5D ve %10D limit deplasman kriterleri uygulanmıştır. Sonuçlar, kazıklar arası mesafenin artmasının taşıma gücünde azalmaya sebep olduğunu, helis varlığının ise taşıma gücünü arttırdığını göstermiştir.

Anahtar Kelimeler

• Grup Helisel Kazık
• Taşıma Gücü
• Kazıklar Arası Mesafe
• Laboratuvar Deneyleri

Kaynakça

1. 1. Türedi, Y. (2021). Basınç yüküne maruz helisel kazık davranışının laboratuvar ve arazi deneyleri ile araştırılması. Doktora Tezi, İskenderun Teknik Üniversitesi, Lisansüstü Eğitim Enstitüsü, Hatay, 194.
2. 2. Sakr, M. (2009). Performance of helical piles in oil sand. Canadian Geotechnical Journal, 46(9), 1046-1061.
3. 3. Yılmaz, B. (2016). Helisel kazıklar. Yüksek Lisans Tezi, İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, İstanbul, 165.
4. 4. Livneh, B. & El Naggar, M.H. (2008). Axial testing and numerical modeling of square shaft helical piles under compressive and tensile loading. Canadian Geotechnical Journal, 45(8), 1142-1155.
5. 5. Sakr, M. (2011). Installation and performance characteristics of high-capacity helical piles in cohesionless soil. DFI Journal - The Journal of the Deep Foundations Institute, 5(1), 39-57.
6. 6. Tsuha, C.H.C., Aoki, N., Rault, G., Thorel, L. & Garnier, J. (2012). Evaluation of the efficiencies of helical anchor plates in sand by centrifuge model tests. Canadian Geotechnical Journal, 49(9), 1102-1114.
7. 7. Lutenegger, A.J., Robson, D. & Mohan, P. (2013). Preservation of historic structures and monuments using minimally ınvasive screw piles and helical anchors – two cases. geotechnical engineering for the preservation of monuments and historic sites (Bilotta, Flora, Lirer & Viggiani, Eds.). Taylor & Francis Group, London, 515-522.
8. 8. Harnish, J.L. (2015). Helical pile installation torque and capacity correlations. MSc Thesis, The University of Western Ontario London. 123.

9. 9. Khan, M.U.S. (2016). Estimation of compressive load bearing capacity of helical piles using torque method and induced settlements. MSc Thesis, The University of British Columbia, 103.
10. 10. Pérez, Z.A., Schiavon, J.A., Tsuha, C.H.C., Dias, D. & Thorel, L. (2018). Numerical and experimental study on influence of installation effects on behavior of helical anchors in very dense sand. Canadian Geotechnical Journal, 55(8), 1067-1080.
11. 11. George, B.E., Banerjee, S. & Gandhi, S.R. (2019). Helical piles installed in cohesionless soil by displacement method. International Journal of Geomechanics, 19(7), 04019074.
12. 12. Shahbazi, M., Cerato, A.B., El Naggar, M.H. & Elgamal, A. (2020). Evaluation of seismic soil–structure ınteraction of full-scale grouped helical piles in dense sand. International Journal of Geomechanics, 20(12), 04020228.
13. 13. Ali, K., Ullah, S., Nawaz, H., Ahmad, M., Safdar, M. & Ullah, W. (2022). Experimental modelling of helical piles under axial loading. Pakistan Journal of Engineering and Technology, 5(2), 128-132.
14. 14. Kaya, B. (2022). Kil zeminlerde helisel kazıkların davranışı. Yüksek Lisans Tezi, Çukurova Üniversitesi, Fen Bilimleri Enstitüsü, Adana, 101.
15. 15. Çolak, A. (2023). Helisel kazıkların taşıma gücü kapasitelerinin analitik yöntemler ve sayısal analiz yöntemleri kullanılarak araştırılması. Yüksek Lisans Tezi, Erciyes Üniversitesi, Fen Bilimleri Enstitüsü, Kayseri, 61.
16. 16. Alwalan, M. & Alnuaim A. (2022). Axial loading effect on the behavior of large helical pile groups in sandy soil. Arabian Journal for Science and Engineering, 47, 5017-5031.
17. 17. Elsherbiny, Z.H. & El Naggar, M.H. (2013). Axial compressive capacity of helical piles from field tests and numerical study. Canadian Geotechnical Journal, 50(12), 1191-1203.
18. 18. Lanyi-Bennett S.A. & Deng, L. (2019). Axial load testing of helical pile groups in a glaciolacustrine clay. Canadian Geotechnical Journal, 56(2), 187-197.
19. 19. Mittal, S. & Mukherjee, S. (2013). Vertical uplift capacity of a group of helical screw anchors in sand. Indian Geotechnical Journal, 43(3), 238-250.
20. 20. Nowkandeh, M.J. & Choobbasti, A.J. (2021). Numerical study of single helical piles and helical pile groups under compressive loading in cohesive and cohesionless soils. Bulletin of Engineering Geology and the Environment, 4001-4023.
21. 21. Shaheen, W.A. & Demars, K.R. (1995). Interaction of multiple helical earth anchors embedded in granular soil. Marine Georesources and Geotechnology, 13, 357-374
22. 22. Vignesh, V. & Muthukumar M. (2023). Experimental and numerical study of group effect on the behavior of helical piles in soft clays under uplift and lateral loading. Ocean Engineering, 268, 113500.
23. 23. Bak, J., Choi, B.H., Lee, J., Bae, J., Lee, K. & Kim, D. (2019). Behaviour of single and group helical piles in sands from model experiments. 2nd International Conference on Building Materials and Materials Engineering (ICBMM 2018), 278.
24. 24. Elsherbiny, Z. (2011). Axial and lateral performance of helical pile groups. MSc Thesis, The University of Western Ontario, London, Canada. 172.
25. 25. Mendoza, C.C., Cunha, R. & Lizcano, A. (2015). Mechanical and numerical behavior of groups of screw (type) piles founded in a tropical soil of the Midwestern Brazil. Computers and Geotechnics, 67, 187-203.
26. 26. Mukherjee, A. & Mittal, S. (2015). Vertical uplift capacity of a group of equally spaced helical screw anchors in sand. 6th International Conference on Structural Engineering and Construction Management, 11-13 December, Kandy, Sri Lanka, 25-31.
27. 27. Sakr, M., Nazir, A., Farouk, A. & Ads, A. (2015). Uplift capacity of helical piles in sand. International Conference on Advances in Structural and Geotechnical Engineering (ICASGE’15), 6-9 April 2015, Hurghada, Egypt, 20.
28. 28. Özaydın, K. (2016). Zemin mekaniği. Birsen Kitabevi, 326.
29. 29. Türedi, Y., Emirler, B., Örnek, M. & Yıldız, A. (2023). Helisel kazıklarda helis çapının basınç yüküne etkisinin laboratuvar deneyleri ile araştırılması, Çukurova Üniversitesi Mühendislik Fakültesi Dergisi, 38 (4), 1013-1022.
30. 30. Türedi, Y. ve Örnek, M. (2016). Kare temeller altında gerilme ve taşıma gücü analizi. Çukurova Üniversitesi Mühendislik-Mimarlık Fakültesi Dergisi, 31(2), 59-66.
31. 31. O’Neill, M.W. & Reese, L.C. (1999). Drilled shafts: construction procedures and design methods. Publication No. FHWA-IF-99-025, Office of Infrastructure, Federal Highway Administration, Washington D.C., 537.
32. 32. Örnek, M., Yıldız, A. Emirler, B. & Türedi, Y. (2023) Arazide farklı yüklemelere maruz helisel kazıklar için optimum tasarım parametrelerinin önerilmesi. TÜBİTAK Destekli Bilimsel Araştırma Projesi (TÜBİTAK 1001-No:218M571), 395.
33. 33. Türedi, Y. & Örnek, M. (2020). Analysis of model helical piles subjected to axial compression, Građevinar. Journal of the Croatian Association of Civil Engineers, 9, 759-769.