ارزیابی سطوح عملکرد و ضریب رفتار قاب‌های خمشی پیش‌تنیده به روش تحلیل غیر‌خطی بار‌افزون

نوع مقاله: علمی - پژوهشی

نویسندگان

1 کارشناس ارشد مهندسی سازه، دانشگاه یاسوج، یاسوج، ایران

2 استادیار، گروه مهندسی عمران، دانشکده فنی و مهندسی، دانشگاه یاسوج، یاسوج، ایران

چکیده

امروزه استفاده از سیستم پیش‌تنیدگی به روش‌های مختلف در قاب‌های باربر ثقلی بسیار رایج است. می‌توان از این فناوری در قاب‌های باربر جانبی نیز استفاده کرد. علاوه بر قاب خمشی ساده، می‌توان در قاب‌های خمشی متوسط و ویژه هم از این فناوری بهره برد. طبق آیین‌نامه‌های طراحی موجود، استفاده از دال‌های پیش‌تنیده‌ی پس‌کشیده به‌عنوان عضو اصلی سیستم باربرجانبی در قاب‌های خمشی ویژه ممنوع است. همچنین استفاده از تیر‌های پیش‌تنیده در قاب‌های خمشی ویژه شامل محدودیت‌هایی است. در این پژوهش پس از طراحی قاب‌های خمشی ویژه دارای تیر‌ها و دال‌های پیش‌تنیده به روش‌های مرسوم و با در نظر گرفتن ضوابط ویژه‌ی طراحی لرزه‌ای و اعمال محدودیت‌های آیین‌نامه‌ای به‌منظور بررسی سطوح عملکرد و آسیب‌پذیری این نوع قاب‌ها، بر روی آن‌ها تحلیل استاتیکی غیر‌خطی بارافزون انجام شده است. پس از انجام تحلیل استاتیکی غیرخطی، تغییرمکان هدف قاب‌های موردنظر محاسبه شده و روند تشکیل مفاصل پلاستیک و معیار‌های پذیرش برای این مفاصل بررسی شده‌ است. همچنین به‌منظور بررسی تأثیر پیش‌تنیدگی بر رفتار لرزه‌ای قاب‌های خمشی ویژه‌ی پیش‌تنیده، ضریب رفتار و پارامتر‌های لرزه‌ای مربوط به این نوع قاب‌ها به‌دست آمده‌ است. در نهایت همه‌ی مراحل فوق برای قاب‌های خمشی ویژه‌ی بتن‌آرمه متناظر نیز تکرار شده و نتایج حاصل با قاب‌های پیش‌تنیده مقایسه شده است. نتایج به‌دست آمده نشان می‌دهد که علاوه بر اعمال محدودیت‌های مربوط به تیر‌های پیش‌تنیده در قاب‌های خمشی ویژه، سطوح عملکرد کلی و سطوح عملکرد اعضای این قاب‌ها نسبت به قاب‌های بتن‌آرمه قابل‌ پذیرش هستند. برای قاب‌های پیش‌تنیده، ضریب شکل‌پذیری و ضریب رفتار بالاتری نسبت به قاب‌های بتن‌آرمه به‌دست آمده و مقدار برش پایه در مقاومت تسلیم برای این نوع قاب‌‌ها بطور قابل‌توجهی کمتر از مقدار مشابه در قاب‌های بتن‌آرمه محاسبه شده است.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Evaluation of Performance Levels and Response Modification Factors for Prestressed Reinforced Concrete Frames Using Nonlinear Pushover Analysis

نویسندگان [English]

  • Vahid Sadeghi 1
  • Ali Alipour 2
  • Shamsedin Hashemi 2
1 Master of Science, Department of Civil Engineering, Faculty of Engineering, Yasouj University, Yasouj, Iran
2 Assistant Professor, Department of Civil Engineering,Faculty of Engineering, Yasuj University, Yasuj, Iran
چکیده [English]

The use of different methods of prestressing systems is very common in gravity frames at the present time. This technology can also be used in lateral load resisting frames. In addition to ordinary moment frames, this technology can be used in intermediate and special moment resisting frames. The use of post-tensioned prestressed slabs as primary members of the seismic load resisting load path in special moment resisting frames is not permitted based on available codes. The use of prestressed beams in special moment resisting frames includes some limitations. In this study, after the design of special prestressed moment frames with prestressed beams and slabs using conventional methods, considering special seismic design criteria, nonlinear pushover static analysis has been carried out in order to investigate performance levels and vulnerability of this type of frames. After performing nonlinear static analysis, target displacement of desired frames has been calculated and the plastic hinges formation sequence and related acceptance criteria for these hinges is investigated. Also, in order to study the effect of prestressing on seismic behavior of special prestressed moment resisting frames, response modification factor and related seismic parameters of this type of frames are obtained. Finally, all the above steps are repeated for the corresponding reinforced concrete special moment resisting frames, and the results were compared with prestressed frames. The obtained results show that in addition to applying restrictions on the use of prestressed beams in special moment resisting frames, target building performance levels and structural performance levels are acceptable, compared to reinforced concrete frames. Higher ductility factor and response modification factor has been achieved for prestressed frames compared to reinforced concrete frames and the base shear at yield strength for this type of frames are considerably lower than the similar value for reinforced concrete frames.

کلیدواژه‌ها [English]

  • Prestressed Concrete Special moment resisting frame
  • Performance levels
  • Plastic hinge
  • Nonlinear static analysis
  • target displacement
  • Response modification factor

[1]         Hurst, M. (2003). Prestressed Concrete Design (2nd Edition). London and New York: Taylor & Francis e-Library.

[2]         Wei, W., Zhang, H., and Li, Z. (2012). Seismic Performances of Large-Span Prestressed Concrete Frame Structure by Shaking Table Tests. Journal of Natural Sciences, 17(3), 261–267.

[3]         Lou, T., Lopes, S. M. R., and Lopes, A. V. (2013). Nonlinear and time-dependent analysis of continuous unbonded prestressed concrete beams. Computers & Structures, 119, 166–176.

[4]         Kim, K. S., and Lee, D. H. (2012). Nonlinear Analysis Method for Continuous Post-Tensioned Concrete Members with Unbonded Tendons. Engineering Structures, 40, 487–500.

[5]         Astawa, M. D., Tavio, and Raka, I. G. P. (2013). Ductile Structure Framework of Earthquake Resistant of Highrise Building on Exterior Beam-Column Joint with the Partial Prestressed Concrete Beam-Column Reinforced Concrete. Procedia Engineering, 54, 413–427.

[6]         Kulkarni, S. S., Sureban, A. C., Chappalagaon, M., and Sharif, M. (2016). Comparative Study on Design of RCC and PSC Beams. International Journal of Advanced Research in Science, Engineering and Technology, 3(6), 69–76.

[7]         Poluraju, P., and Rao, P. V. S. N. (2011). Pushover Analysis of Reinforced Concrete Frame Structure Using SAP2000. International Journal of Earth Sciences and Engineering, 4(6), 684–690.

[8]         Cinitha, A., Umesha, P. k., and IYER, N. R. (2012). Nonlinear Static Analysis to Assess Seismic Performance and Vulnerability of Code-Conforming RC Buildings. WSEAS Transactions on Applied and Theoretical Mechanics, 7(1), 39–48.

[9]         Vijayakumar, A., and Babu, D. L. V. (2012). Pushover Analysis of Existing Reinforced Concrete Framed Structures. European Journal of Scientific Research, 71(2), 195–202.

[10]       Mouzzoun, M., Moustachi, O., Taleb, A., and Jalal, S. (2013). Seismic Performance Assessment of Reinforced Concrete Buildings Using Pushover Analysis. IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE), 5(1), 44–49.

[11]       Hakim, R. A., Alama, M. S., and Ashour, S. A. (2014). Seismic Assessment of an RC Building Using Pushover Analysis. Engineering, Technology & Applied Science Research, 4(3), 631.

[12]       Bansal, A., and Patidar, A. (2016). Pushover Analysis of Multistorey Buildings Having Flat Slab and Grid Slab. International Journal of Engineering Science Invention Research & Development, 2(7), 435–441.

[13]       Koni, B. B., and Dyavanal, S. S. (2016). Performance Based Evaluation of Flat Slab Structures with Square Columns. International Journal of Research in Engineering and Technology, 5(7), 282–289.

[14]       Boonyapinyo, V., Warnitchai, P., and Intaboot, N. (2006). Seismic Capacity Evaluation of Post-Tensioned Concrete Slab-Column Frame Buildings by Pushover Analysis. Journal of Science and Technology, 28(5), 1033–1048.

[15]       Shah, B. A., Mistry, D. A., and Patodi, S. C. (2011). Seismic Evaluation of Buildings with Post-Tensioned Floors by Pushover Analysis. Journal of Structural Engineering, 38(5), 417–427.

[16]       B.Hancıoglu, M.S.Kırcıl, S. D. U. (2013). Seismic Performance Evaluation of a Post-Tensioned Frame Building. In: 4th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering. Istanbul, Turkey: National Technical University of Athens.

[17]       Javidi, M. (2013). Seismic Performance Evaluation of Concrete Frames with Prestressed Columns. Yasouj University.

[18]       Integrated Solutions for Building Prestressing by Post-Tensioning. (2012). FREYSSINET -Sustainable Technology. [Online] Available at: http://www.freyssinet.com/freyssinet/wfreyssinet_en.nsf [Accessed October 25, 2016].

[19]       Schokker, A. J., Lee, S. C., and Scanlon, A. (2002). Analytical Study of The Effects of Tendon Layout on The Performance of Post-Tensioned Two-Way Slab Systems. In: 4th Structural Specialty Conference of the Canadian Society for Civil Engineering. Montréal, Québec.

[20]       ACI Committee 318, and American Concrete Institute. (2014). Building Code Requirements for Structural Concrete (ACI 318M-14), an ACI Standard, and Commentary on Building Code Requirements for Structural Concrete (ACI 318RM-14), an ACI report. American Concrete Institute.

[21]       Hamburger, R. O. (1997). A Framework for Performance-Based Earthquake Resistive Design. Berkeley ,California: NISEE , University of California.

[22]       ATC 40, Seismic Evaluation and Retrofit of Concrete Buildings. (1996). Applied Technology Council. Redwood City, California: Applied Technology Council.

[23]       FEMA 356, Prestandard and Commentary for the Seismic Rehabilitation of Buildings. (2000). Washington D.C: Federal Emergency Management Agency.

[24]       FEMA 440, Improvement of Nonlinear Static Seismic Analysis Procedure. (2005). Federal Emergency Management Agency. Redwood City.

[25]       ASCE/SEI 41. Evaluation and Retrofit of Existing Buildings (2013). Reston, VA: American Society of Civil Engineers.

[26]       Taghinezhad, R. (2009). Seismic Design and Rehabilitation of Structures Based on the Performance Level. Tehran: Academic Books Publication.

[27]       Berkeley, C. (2016). CSI Analysis Reference Manual for SAP2000, ETABS, SAFE and CSiBridge. Computers and Structures, Inc., Berkeley, California.

[28]       Ghobarah, A. (2001). Performance-Based Design in Earthquake Engineering: State of Development. Engineering Structures, 23(8), 878–884.

[29]       Shafiei Tehrany, R. (2008). Nonlinear Dynamic and Static Analysis of I-5 Ravenna Bridge. Master of Science Thesis in Civil Engineering, Washington State University.

[30]       Tasnimi, A. A., and Massumi, A. (2006). Estimation of Response Modification Factors for RC-MRF Structures. Building and Housing Research Center. Tehran: Pub. No. G- 436.

[31]       Lakshmanan, N. (2006). Seismic Evaluation and Retrofitting of Buildings and Structures. ISET Journal of Earthquake Technology, 43(1), 31–48.

[32]       Dy, A. F., and Oreta, A. W. (2015). Seismic Vulnerability Assessment of Setback Buildings Using Pushover Analysis. In: Proceedings of the Tenth Pacific Conference on Earthquake Engineering Building an Earthquake-Resilient Pacific. Sydney, Australia.

[33]       Mander, J. B., Priestley, M. J. N., and Park, R. (1988). Theoretical Stress-Strain Model for Confined Concrete. Journal of structural engineering, 114(8), 1804–1826.

[34]       Sharma, A., Reddy, G. R., Vaze, K. K., and Eligehausen, R. (2013). Pushover Experiment and Analysis of a Full Scale Non-Seismically Detailed RC Structure. Engineering Structures, 46, 218–233.