ÇOKLU DEPREM SERİLERİNİN DÜZENSİZ YAPILARIN SİSMİK DAVRANIŞINA ETKİLERİ

Depremden sonra hasar görmüş bölgelerde yürütülen yerinde inceleme çalışmalarında çoklu deprem etkileri sıklıkla görülmektedir. Birçok yapı, ana depremi hasarsız ya da az hasarlı atlatırken, rijitlik ve dayanımı azalmış yapıya artçı deprem etkimesi durumunda gözlenen hasar genellikle artmaktadır. Bazı durumlarda yapı ana depremi güvenli bir şekilde atlatırken, artçı depremden sonra göçebilmektedir. Literatürde, çoklu deprem serilerine maruz kalmış düzensiz betonarme yapıların sismik davranışlarını inceleyen az sayıda çalışma vardır. Bu çalışmada, çoklu deprem serilerinin düzensiz betonarme yapıların kalıcı deplasman değerlerine etkilerini araştırılmaktadır. Bu sebeple, düzensiz üç adet mevcut betonarme yapı seçilmiş ve çoklu deprem serileri altında, doğrusal olmayan zaman tanım alanında analizleri gerçekleştirilmiştir. Malzemedeki bozulma etkilerini incelemek için, seçilen yapılar hem azalım etkilerini dikkate alabilen hem de azalım etkilerini dikkate alamayan malzeme modelleri kullanılarak analiz edilmişlerdir. Analiz sonuçlarının incelenmesinden, azalım etkilerini dikkate almayan malzeme modellerinin çoklu deprem serileri altındaki sismik davranışı gerçekçi bir şekilde yansıtamadıkları belirlenmiştir. Bu sebeple bozulma etkilerini doğru olarak yakalayabilmek için azalım etkilerini dikkate alan malzeme modellerinin kullanılması gerekmektedir. Ayrıca, çalışmanın sonucunda düzensizlik etkilerinin kalıcı deplasmanları arttırdıkları belirlenmiştir.

Anahtar Kelimeler:

Artçı depremler, Düzensiz betonarme yapılar, Azalımsal malzeme modelleri, Genişletilmiş N2 yöntemi, Çoklu depremler

Effects of Multiple Earthquake Sequences on Seismic Behavior of Irregular Buildings

Effects of multiple earthquakes are frequently observed after conducted reconnaissance studies in the earthquake affected region. Many structures withstand the main shock without having intense damage. However, when an aftershock hits the previously deteriorated structure, the observed damage is generally altered. There are some cases where the structure withstands the main excitation, however collapsed when an its subjected to a ground sequence. Fewer studies in the literature have focused on the seismic behavior of irregular reinforced concrete structures subjected to multiple earthquakes. This research investigates the effects of multiple earthquake sequences on residual displacement values of irregular reinforced concrete structures. For that reason, three irregular existing reinforced concrete structures are selected, and nonlinear time history analysis are conducted under multiple earthquake sequences. To demonstrate the effect of deteriorations on the material, the selected structures were analyzed using both non-degrading and degrading material models. The results of the analyses revealed the fact that non-degrading models are incapable of estimating the seismic response under multiple earthquake sequences. Hence, degrading material models should be used to capture the deterioration effects accurately. Further, it is concluded that irregularity effects increase the values of the residual displacements.

Keywords:

Aftershocks, Irregular RC structures, Degrading material models, Extended N2 method, Multiple earthquake,

PDF

___

1. Abdelnaby, A.E., Elnashai A.S. (2014) Performance of Degrading Reinforced Concrete Frame Systems Under the Tohoku and Christchurch Earthquake Sequences, Journal of Earthquake Engineering, 18 (7), 1009-1036. doi: 10.1080/13632469.2014.923796
2. Afet Bölgelerinde Yapılacak Yapılar Hakkında Yönetmelik (ABYYHY). (1975) T.C. İmar ve İskan Bakanlığı, Ankara, Türkiye.
3. Amadio, C., Fragiacomo, M., Macorini, L. (2003) The Effects of Repeated Earthquake Ground Motions on The Non-linear Response of SDOF Systems, Earthquake Engineering and Structural Dynamics, 32, 291-308. doi: 10.1002/eqe.225
4. Aschheim, M., Black, E. (1999) Effects of Prior Earthquake Damage on Response of Simple Stiffness-Degrading Structures, Engineering Spectra, 15, 1-24. doi: 10.1193/1.1586026
5. Carvalho, E.C., Coelho, E., Compos-Costa A. (1999) Preparation of the Full-Scale Test on Reinforced Concrete Frames: Characteristic of the Test Specimens, Materials and Testing Conditions, ICON Report, Innovative Seismic Design Concepts for New and Existing Structures, European TMR Network, LNEC.
6. Elnashai, A.S., Papanikolaou, V., Lee, D. (2002) ZEUS-NL – A system for inelastic analysis of structures. Mid-America Earthquake Center, Urbana-Champaign Program Release 2002.
7. Erdik, M. (2000) Report on 1999 Kocaeli and Düzce (Turkey) earthquakes, Proceedings of the 3rd International Workshop on Structural Control, Paris-France, 6–8 July 2000, 149-186. doi: 10.1142/9789812811707_0018
8. Eurocode 8. (2006) Design of Structures for Earthquake Resistance, Part 1: General Rules, Seismic Actions and Rules for Buildings. European Standard EN 1998-1, European Committee for Standardization, Brüksel.
9. Fajfar, P., Gaspersic, P. (1996) The N2 Method for the Seismic Damage Analysis of RC Buildings. Earthquake Engineering and Structural Dynamics, 25: 31-46. doi: 10.1002/(SICI)1096- 9845(199601)25:1<31::AID-EQE534>3.0.CO;2-V
10. Fardis, M.N. (2002) Design of an irregular building for the SPEAR project-description of the 3-storey structure. Res Report Univ Patras Greece.
11. Federal Emergency Management Agency (FEMA). (2000) Prestandard and commentary for the seismic rehabilitation of buildings. FEMA 356. Washington DC, Amerika Birleşik Devletleri.
12. Gomes, A., Appleton, J. (1997) Nonlinear Cyclic Stress-Strain Relationship of Reinforcing Bars Including Buckling, Engineering Structures, 19(10): 822-826. doi: 10.1016/S0141-0296(97)00166-1
13. Hatzigeorgiou, G.D., Beskos D.E. (2009) Inelastic Displacement Ratios for SDOF Structures Subjected to Repeated Earthquakes, Engineering Structures, 31, 2744-2755. doi: 10.1016/j.engstruct.2009.07.002
14. Hatzigeorgiou, G.D., Liolios, A.A. (2010) Nonlinear Behavior of RC Frames Under Repeated Strong Ground Motions, Soil Dynamics and Earthquake Engineering, 30, 1010-1025. doi: 10.1016/j.soildyn.2010.04.013
15. Hatzivassiliou, M., Hatzigeorgiou, G.D. (2015) Seismic Sequence Effects on Three Dimensional Reinforced Concrete Buildings, Soil Dynamics and Earthquake Engineering, 72, 77–88. doi: 10.1016/j.soildyn.2015.02.005
16. Japon Meteroloji Ajansı (JMA). https://www.jma.go.jp/jma/en/2011_Earthquake/Information_on_2011_Earthquake.html, Erişim Tarihi: 16.11.2021.
17. Jeong, S.H.J, Elnashai, A.S. (2004) Analytical Assessment of an Irregular RC Full Scale 3D Test Structure. Mid-America Earthquake Center, Urbana-Champaign Üniversitesi, Amerika Birleşik Devletleri.
18. Kazama, M., Noda, T. (2012) Damage Statistics (Summary of the 2011 off the Pacific Coast of Tohoku Earthquake damage), Soils and Foundations, 52(5), 780-792. doi: 10.1016/j.sandf.2012.11.003
19. Kreslin, M., Fajfar, P. (2012) The extended N2 method considering higher mode effects in both plan and elevation. Bulletin of Earthquake Engineering, 10, 695–715. doi: 10.1007/s10518-011-9319-6
20. Lee, J., Fenves, G. (1998) Plastic Damage Model for Cyclic Loading of Concrete Structures, Journal of Engineering Mechanics, 124 (8), 829-900. D,doi: 10.1061/(ASCE)0733-9399(1998)124:8(892)
21. Menegotto, M., Pinto, P. (1973) Method of Analysis for Cyclically Loaded RC Plane Frames Including Changes in Geometry and Non-elastic Behavior of Elements Under Combined Normal Force and Bending, Symp. Resistance and Ultimate Deformability of Structures Acted on by Well Defined Repeated Loads, IABSE Reports Vol 13, Lisbon.
22. Moshref, A., Khanmohammadi, M., Tehranizadeh, M. (2017) Assessment of the Seismic Capacity of Mainshock-damaged Reinforced Concrete Columns. Bulletin of Earthquake Engineering, 15, 291–311. doi: 10.1007/s10518-016-9952-1
23. Oyguc, R. (2016) Seismic Performance of RC School Buildings After 2011 Van Earthquakes. Bulletin of Earthquake Engineering, 14(3):821–47. doi: 10.1007/s10518-015-9857-4
24. Oyguc, R., Güley, E. (2017) Performance Assessment of Aseismically Designed RC School Buildings After October 23, 2011 Van Earthquake. Journal of Performance of Constructed Facilities. doi: 10.1061/(ASCE)CF.1943-5509.0000938.
25. Palermo, M., Trombetti, T. (2016) Experimentally-validated Modeling of Thin RC Sandwich Walls Subjected to Seismic Loads. Engineering Structures, 119, 95–109. doi: 10.1016/j.engstruct.2016.03.070
26. Papanikolaou, V.K., Elnashai, A.S., Pareja, J.F. (2005) Limits of Applicability of Conventional and Adaptive Pushover Analysis for Seismic Response Assessment. Mid-America Earthquake Center, Urbana-Champaign Üniversitesi, Amerika Birleşik Devletleri.
27. Pinho, R., Elnashai A.S. (2000) Dynamic Collapse Testing of a Full-scale Four Storey RC Frame. ISET. Journal of Earthquake Technology, 37(4):143–63.
28. Stratan, A., Fajfar, P. (2003) Seismic Assessment of the SPEAR Test Structure. IKPIR report. Ljubljana Üniversitesi. Çek Cumhuriyeti.
29. Türkiye Bina Deprem Yönetmeliği (TBDY). (2018) Afet ve Acil Durum Yönetimi Başkanlığı, Ankara, Türkiye.
30. Ulusal Standart ve Teknoloji Enstitüsü. (2010) Applicability of nonlinear multiple-degree-of-freedom modeling for design. ATC-76-6. National Institute of Standards and Technology. California, Amerika Birleşik Devletleri.
31. Ulusal Yer bilimi ve Afet Önleme Araştırma Enstitüsü (NIED). National Research Institute for Earth Science and Disaster Prevention. http://www.kyoshin.bosai.go.jp. Erişim tarihi: 26.08.2021
32. Zhang, S., Wang, G., Sa, W. (2013) Damage Evaluation of Concrete Gravity Dams Under Mainshock-Aftershock Seismic Sequences. Soil Dynamics and Earthquake Engineering, 50,16–27. doi: 10.1016/j.soildyn.2013.02.021
33. Zhao, D. (2015) The 2011 Tohoku Earthquake (Mw 9.0) Sequence and Subduction Dynamics in Western Pacific and East Asia. Journal of Asian Earth Science, 98, 26–49. doi: 10.1016/j.jseaes.2014.10.022