Taş Kolonlarla İyileştirilen Zeminlerin Deprem Etkisinde Taşıma Gücü Analizi: 2020 İzmir Depremi Örneği

Abstract

Bu çalışmada Plaxis 2D programı yardımıyla taş kolon ile güçlendirilen iki tabakadan oluşan zemininin deprem etkisi altındaki taşıma gücü değişimi incelenmiştir. Çalışmada 80 m genişliğinde ve 12 m lik problemli kil tabakası, 18 m lik sıkı kum tabakası olmak üzere toplamda 30 m kalınlığındaki zemin modeli oluşturulduktan sonra, üzerine 4 m genişliğinde bir temel ve temel üzerine 0,5 m lik deplasman yükü yüklenerek analizler yapılmıştır. İlk bölümde, oluşturulan bu zemin modeli herhangi bir iyileştirmeye tabi tutulmadan, 30 Ekim 2020 tarihinde meydana gelen İzmir depremi etkisindeki taşıma gücü analizi yapılmıştır. Daha sonra aynı özellikteki zemin modeline 60 cm çapında, iki farklı aralıkta (s/D:2, s/D:3) taş kolonlar eklenerek yine aynı depremin etkisinde analizler yapılarak sonuçlar karşılaştırılmıştır. Çalışma sonucunda deprem etkisinde büyük problem oluşturabilecek yumuşak zeminlerin iyileştirilmesinde taş kolon yönteminin taşıma gücü kaybını önlemede ne kadar etkili bir yöntem olduğu açıkça görülmüştür.

Keywords

• Yumuşak zemin
• Taş kolonlar
• Deprem
• Taşıma gücü
• Sonlu elemanlar

Bearing Capacity Analysis of Soils Improved with Stone Columns Under the Effect of Earthquake: Example of 2020 Izmir Earthquake

Abstract

In this study, with the help of Plaxis 2D program, the change in bearing capacity of the soil, which consists of two layers reinforced with stone columns, under the effect of earthquake is examined. In the study, after creating a soil model of 80 m width and 12 m of problematic clay layer and 18 m of tight sand layer, a total of 30 m thick, analyzes were made by loading a 4 m wide foundation and a 0.5 m displacement load on the foundation. In the first part, the bearing capacity analysis under the influence of the Izmir earthquake, which occurred on October 30, 2020, was carried out without any improvement in this soil model. Then, stone columns with 60 cm diameter and two different intervals (s/D:2, s/D:3) were added to the soil model with the same characteristics, and analyzes were made under the influence of the same earthquake and the results were compared. As a result of the study, it has been clearly seen how effective the stone column method is in preventing the loss of bearing capacity in the improvement of soft soils that may cause major problems in the earthquake effect.

Keywords

• Soft soil
• Stone columns
• Earthquake
• Bearing capacity
• Finite element

References

1. Alzabeebee, S. (2020). Seismic settlement of a strip foundation resting on a dry sand. Natural Hazards, 103, 2395–2425. University of Al-Qadisiyah, Al‑Qadisiyah, Iraq
2. Azzam, WR. (2015). Finite element analysis of skirted foundation adjacent to sand slope under earthquake loading. HBRC J 11(2):231–239
3. Karamitros, DK., Bouckovalas, GD., Chaloulos, YK. (2013). Insight into the seismic liquefaction performance of shallow foundations. J Geotech Geoenvironment Engineering 139(4):599–607
4. Karamitros, DK., Bouckovalas, GD., Chaloulos, YK., Andrianopoulos, KI. (2013). Numerical analysis of liquefaction-induced bearing capacity degradation of shallow foundations on a two-layered soil profile. Soil Dynamic Earthquake Engineering. 44:90–101
5. Karamitros, DK., Bouckovalas, GD., Chaloulos, YK. (2013). Seismic settlements of shallow foundations on liquefiable soil with a clay crust. Soil Dynamic Earthqauke Engineering. 46:64–76
6. Mansour, MF., Abdel-Motaal, MA., Ali AM. (2016). Seismic bearing capacity of shallow foundations on partially liquefiable saturated sand. International Journal of Geotechnical Engineer. 10(2):123–134
7. Nguyen, QV., Fatahi, B., Hokmabadi, AS. (2016). The effects of foundation size on the seismic performance of buildings considering the soil–foundation–structure interaction. Structural Engineering and Mechanics. 58(6):1045–1075
8. Raikar P. (2016). Modelling Soil Damping for Suction Pile Foundations. Master of Science Thesis, Delft University of Technology.

9. S. Kholdebarin, A., Massumi, A., Davoodi, M., Tabatabaiefar, HR. (2008). Comparing of normal stress distribution in static and dynamic soil–structure interaction analyses. In: AIP conference proceedings, pp 650–657
10. S. Kholdebarin, A., Massumi, A., Davoodi, M. (2016). Seismic bearing capacity of shallow footings on cementimproved soils. Earthquake Structure. 10(1):179–190
11. Vivek, P. (2011). Static and dynamic interference of strip footings in layered soil. Master Thesis. Indian Institute of Technology Kanpur, India.