Abstract

Bu çalışmada, kurşun çekirdekli kauçuk izolatörlü yapılarda, izolasyon seviyesinde meydana gelen en büyük deplasman, kuvvet ve ivme değerleri zaman tanım alanında doğrusal olmayan hesap yöntemi kullanılarak incelenmiştir. Dinamik analizlerde kullanılan deprem kayıtları dört farklı yöntem ile ölçeklendirilmiştir. Çift doğrultulu analizler gerçekleştirmek amacıyla, deprem kayıtlarına ait her iki yatay bileşen aynı zamanda yalıtım birimlerine uygulanmıştır. Analizlerde çevrimsel hareket nedeniyle kurşun çekirdekte oluşan ısınma sonucu meydana gelen dayanım kaybı dikkate alınmıştır. Ayrıca sismik izolasyonlu yapılarda, izolasyon periyodunu temsil eden beş periyot (Tiso=2.5s, 2.75s, 3.0s, 3.25s ve 3.5s) ile yalıtım birimi için dayanımı temsil eden dört karakteristik dayanım oranı (Q/W=0.75, 0.90, 0.105 ve 0.120) dikkate alınmıştır. Çalışma sonucunda izolasyon seviyesinde meydana gelen en büyük ivme ve deplasman değerlerinde, farklı ölçeklendirme yöntemleri nedeniyle %10-13 oranında değişim gözlenmiştir. Ayrıca izolatör kuvvetlerinde %3 civarında değişim olup kayda değer bir farklılık meydana gelmemiştir.

References

[1] Naeim, F., and Kelly, J. M. (1999). Design of seismic isolated structures : from theory to practice. John Wiley.

[2] Turkish Building Earthquake Code (TBEC), Principles for the design of buildings under earthquake, Ankara, Turkey, 2018.

[3] Eurocode8: Design of Structures for Earthquake Resistance- Part 1: General Rules, Seismic Actions and Rules for Buildings, EN 1998-1, 2004.

[4] American Society of Civil Engineers/Structural Engineering Institute, 2016. “Minimum Design Loads For Buildings And Other Structures”, ASCE/SEI 7-16, Reston, V.A.

[5] Bommer JJ, Acevedo AB. The use of real earthquake accelerograms as input to dynamic analysis. J Earthq Eng 2004;8:43–91.

[6] Nau JM, Hall WJ. Scaling Methods for Earthquake Response Spectra. J Struct Eng 1984;110:1533–48.

[7] Shome N, Cornell CA, Bazzurro P, Carballo JE. Earthquakes, records, and nonlinear responses. Earthq Spectra 1998;14:469–500.

[8] Malhotra PK. Strong-motion records for site-specific analysis. Earthq Spectra 2003;19:557–78.

[9] Weng Y.T., Tsai K.C., Chan Y.R. A ground motion scaling method considering highermode effects and structural characteristics. Earthq Spectra 2010;26:841–786.

[10] Kwong NS, Chopra AK, Mcguire RK. A framework for the evaluation of ground motion selection and modification procedures. Earthq Eng Struct Dyn 2015;44:795–815.

[11] Marasco S, Cimellaro GP. A new energy-based ground motion selection and modification method limiting the dynamic response dispersion and preserving the median demand. Bull Earthq Eng 2018;16:561–81.

[12] Kottke A, Rathje EM. A Semi-Automated Procedure for Selecting and Scaling Recorded Earthquake Motions for Dynamic Analysis. Earthq Spectra 2019;24:911–32.

[13] Zhang R, Wang D, Chen X, Li H. Weighted and Unweighted Scaling Methods for Ground Motion Selection in Time-history Analysis of Structures. J Earthq Eng 2020:1–36.

[14] Eren N, Sucuoğlu H, Pinho R. Interstory drift based scaling of earthquake ground motions. Earthq Eng Struct Dyn 2021;50:3814–30.

[15] Kalkan E, Chopra AK. Modal-Pushover-Based Ground-Motion Scaling Procedure. J Struct Eng 2011;137:298–310.

[16] Huang Y-N, Whittaker AS, Luco N, Hamburger RO. Scaling Earthquake Ground Motions for Performance-Based Assessment of Buildings. J Struct Eng 2011;137:311–21.

[17] Pant DR, Maharjan M. On selection and scaling of ground motions for analysis of seismically isolated structures. Earthq Eng Eng Vib 2016;15:633–48.

[18] Michaud D, Léger P. Ground motions selection and scaling for nonlinear dynamic analysis of structures located in Eastern North America. Can J Civ Eng 2014;41:232–44.

[19] Pant DR. Influence of scaling of different types of ground motions on analysis of code-compliant four-story reinforced concrete buildings isolated with elastomeric bearings. Eng Struct 2017;135:53–67.

[20] Open System for Earthquake Engineering Simulation (OpenSees), 2021. Version: 3.3.0, Software, University of California, Pacific Earthquake Engineering Research Center, Berkeley, California, 2021. http://opensees.berkeley.edu.

[21] Alhan C, Şahin F. Protecting vibration-sensitive contents: An investigation of floor accelerations in seismically isolated buildings. Bull Earthq Eng 2011;9:1203–26.

[22] Robinson WH. Lead-Rubber Hysteretic Bearings Suitable for Protecting Structures During Earthquakes. Earthq Eng Struct Dyn 1982;10:593–604.

[23] Ozdemir G, Dicleli M. Effect of lead core heating on the seismic performance of bridges isolated with LRB in near-fault zones. Earthq Eng Struct Dyn 2012;41:1989–2007. 

[24] Seismic Isolation for Architects.

[25] Ozdemir G, Constantinou MC. Evaluation of equivalent lateral force procedure in estimating seismic isolator displacements. Soil Dyn Earthq Eng 2010;30:1036–42.

[26] PEER Ground Motion Database-Beta Version With special thanks to: Technical Report for the PEER Ground Motion Database Web Application. 2010.