Tebriz Metro 2 hattı boyunca sıvılaşmaya bağlı olarak meydana gelen oturma tehlikesi

Abstract

Deprem nedeniyle sıvılaşma meydana geldiğinde, zemin katmanlarının çözülmesi içinde bulunan veya yeraltı yapılarına hasar verebilir. Son yirmi yılda, farklı deneysel yöntemler alan ve laboratuvar test verilerine dayandırılarak hacimsel gerilme (zemin oturması) ve maksimum kayma gerginliğini belirlemek için kullanıldı. Bu çalışmanın temel amacı, zemin sıvılaşmasından sonra zemin oturma oranı oranının değerlendirilmesi ve sıvılaşma potansiyel endeksi (LPI) ile oturma arasındaki çalışma ilişkisinin değerlendirilmesidir. Tebriz Metro 2 Hattı boyunca Standard Penetrasyon testi (SPT) 54 sondaj deliğindeki sonuçlarından zemin katmanlarının sıvılaşma potansiyelini tahmin etmek için kullanıldı. Daha sonra hem kuru hem de doymuş zemin katmanlarında sıvılaştırmaya bağlı olarak zemin katmanlarında oturma oranı hesaplanmıştır. Devamında LPI hesaplanmıştır. Çalışmadan elde edilen sonuçlar gösteriyor ki, doymuş zemin katmanlarındaki oturma oranının, yeraltı su seviyesinin üzerindeki zemin katmanlardan belirgin derecede yüksek olduğunu ve zemin katmanlarının yoğunluğunun arttığında oturma oranının ve zemin hacimsel gerilimin azaldığını gösterdi. Ayrıca, zemin katmanlarında LPI ve zemin oturma değerleri arasında iyi bir uyum var.

Keywords

• Sıvılaşma,Standard penetrasyon testi (SPT),Zemin oturmasi (hacimsel gerilme),Sıvılaşma potansiyel indeksi (LPI),Tabriz Metro 2 hatti

Settlements hazard of soil due to liquefaction along Tabriz Metro line 2

Abstract

After the occurrence of liquefaction due to earthquake, the settlement of soil layers damage to structures located on the ground or the underground. In the last two decades, different experimental methods were used to determine the rate of volumetric strain (settlement) and maximum shear strain based on field and laboratory test data. The main purpose of the present study is the evaluation of the rate of settlement after the occurrence of liquefaction in soils and study relationship between liquefaction potential index (LPI) and settlement. The results of the standard resistance penetration test along Tabriz Metro Line 2 used to estimate the liquefaction potential of soil layers in 54 boreholes. Then, the value of settlement in soil layers due to liquefaction in both dry and saturated soil layers were evaluated. In continue, LPI was calculated. The results of this study showed that the rate of settlement in saturated soil layers was remarkably higher than the layers above the underground water level and with an increase in the density of the soil layers, the rate of settlement and soil volumetric strain decreased. Also, there is a good adoption between LPI and settlement values in soil layers.

Keywords

• Liquefaction,Standard penetration test (SPT),Settlement (volumetric strain),Liquefaction potential index (LPI),Tabriz Metro line 2

References

1. Ishihara K, Yoshimine M. “Evaluation of settlement in sand deposits flowing liquefaction during earthquakes”. Journal of soils and foundations, 32(1), 173-178, 1992.
2. Seed H B, Idriss I M. “Simplified procedure for evaluating soil liquefaction potential”. Journal of Soil Mechanics and Foundation Division ASCE, 97(9), 1249–1273, 1971.
3. Seed HB, Idriss IM, Arango I.” Evaluation of liquefaction potential using field performance data”. Journal of Geotechnical Engineering (ASCE), 1093, 458-482, 1983.
4. Idriss IM, Boulanger RW. “Semi-empirical procedures for evaluating liquefaction potential during earthquakes”. Soil Dynamic and Earthquake Engineering, 26, 115-130, 2006.
5. Idriss IM, Boulanger RW. “SPT-Based Liquefaction Triggering Procedures”. Report No. UCD/CGM-10/02, Center for Geotechnical Modeling, University of California, Davis, 2010.
6. Robertson PK, Wride CE. “Evaluation cyclic liquefaction potential using the cone penetration test”. Canadian Geotechnical Journal, 35(3), 442-459, 1998.
7. Andrus RD, Stokoe KH. “Liquefaction Resistance Based on Shear Wave Velocity NCEER Workshop on Evaluation of Liquefaction Resistance of Soils”. Technical Report NCEER-97-0022. TL. Youd and IM. Idriss, Eds, Held 4-5 January 1996, Salt lake City, UT, NCEER, Buffalo, NY, 88-128, 1997.
8. Andrus RD, Piratheepan P, Ellis BS, Zhang J, Juang HC. “Comparing liquefaction evaluation methods using penetration Vs relationship”. Journal of Soil Dynamics and Earthquake Engineering, 24(2), 713-721, 2004.

9. Dabiri R, Askari F, Shafiee A, Jafari MK. “Shear wave velocity based Liquefaction resistance of sand-silt mixtures: deterministic versus probabilistic approach”. Iranian journal of science and technology, Transactions of civil engineering, 35(C2), 199-215, 2011.
10. Askari F, Dabiri R, Shafiee A, Jafari MK. “Effects of non-plastic fines content on cyclic resistance and post liquefaction of sand-silt mixtures based on shear wave velocity”. Journal of seismology and earthquake engineering, 12(1, 2), 13-24, 2010.
11. Pyke R, Seed HB, Chan CK. “Settlement of sands under multidirectional shaking”. Journal of Geotechnical Engineering ASCE, 101(4), 379 -398, 1975.
12. Silver ML, Seed HB.”Volume changes in sands during cyclic load”. Journal of Soil Mechanics and Foundation Division, ASCE, 97(SM9), 1171-1182, 1971.
13. Lee KL, Albaisa A. ”Earthquake ınduced settlements in saturated sands”. Journal of the Geotechnical Engineering Division ASCE, 100(4), 387-406, 1974.
14. Tatsuoka F, Sasaki T, Yamada S. “Settlement in saturated sand ınduced by cyclic undrained simple shear”. 8th World Conference on Earthquake Engineering, Sanfrancisco, 3, 255-262, 1982.
15. Tokimatsu K, Seed HB.”Evaluation of settlements in sand due to earthquake shaking”. Journal of Geotechnical Engineering Division (ASCE), 113(8), 861-878, 1987.
16. Shamato Y, Zhang J, Sato M. “Method for evaluating residual post liquefaction ground settlement and horizontal displacement”. Journal of Soils and Foundations, Special, 2, 69-83, 1998.
17. Wu J, Seed RB. ”Estimation of liquefaction-ınduced ground settlement (case studies)”. 5th International Conference on Case Histories in Geotechnical Engineering, Missouri University of science and Technology, Missouri, USA, 13-17 April, 2004.
18. Cetin KO, Unutmaz B. “Probabilistic models for the assessment of post cyclic soil deformations”. 9th ASCE Specialty Conference on Probabilistic Mechanics and Structural Reliability, Albequerque, New Mexico, USA, 26-28 July, 2004.
19. Chen Q, Wang CH, Juang HC. “Probabilistic and spatial assessment of liquefaction-induced settlements through multiscale random field models”. Engineering Geology, 21(2), 135-149, 2016.
20. http://google.com/earth/(07/30/2014).
21. Amiranlou H, Pourkermani M, Dabiri R, Qoreshi M, Buzari S. “Seismic geotechnical micro zonation of tabriz city at veiw of the site affect based on the simulated earthquake”. Open Journal of Earthquake Research, 5, 114-121, 2016.
22. Ghobadi MH, Firuzi M, Asghari E. “Relationships between geological formations and ground water chemistry and their effects on concrete lining of tunnels (case study: Tabriz Metro Line 2)”. Environmental Earth Science, 75(3), 2-14, 2016.
23. Idriss IM. “An update to the Seed-Idriss simplified procedure for evaluating liquefaction potential”. In: Proceedings, TRB workshop on new approaches to liquefaction, publication no. FHWARD-Federal Highway Administration, 99-165, 1999.
24. Road, housing and urban development research center, “Iran design building against earthquake No. 2800-Version 4”. Tehran, Iran, 2014. (In Persian).
25. Skempton AK. “Standard penetration test procedures and the effects in sands of overburden pressure, relative density, particle size, aging and over consolidation”. Journal of Geotechnique, 36(3), 425-447, 1986.
26. Hynes ME, Olsen RS. “Influence of Confining Stress on Liquefaction Resistance”. Proceeding, International Workshop on the Physics and Mechanics of Soil Liquefaction, Baltimore, Maryland, U.S.A, 10-11 September 1998.
27. Iwasaki T, Tokida K, Tatsuko F, Yasuda S. “A practical method for assessing soil liquefaction potential based on case studies at various sites in Japan”. Proc., 2nd International Conference on Microzonation for safer construction, San Francisco, November 26-December 1, 1978.
28. Iwasaki T, Tokida K, Tatsuoka F, Watanabe S, Yasuda S, Sato H. “Microzonation for soil liquefaction potential using simplified methods”. Proc., 3rd International Conference on Earthquake Microzonation, Seattle, Washington, USA, 28 June-1 July , 1982.
29. Sonmez M, Gokceoglu C. “A liquefaction severity index suggested for engineering practice”. Environmental Geology, 48(2), 81-91, 2005.