ضریب اصلاح m برای میانقاب‌های با و بدون بازشو بر اساس اطلاعات آزمایشگاهی

نوع مقاله : Articles

نویسندگان

1 پژوهشکده مهندسی سازه، پژوهشگاه بین‌المللی زلزله‌شناسی و مهندسی زلزله، تهران، ایران

2 مؤسسه آموزش عالی آیندگان، تنکابن، ایران

چکیده

میانقاب، دیواری است که در داخل و در تماس کامل با قاب اجرا می‌شود و سختی و مقاومت آن را به مقدار قابل‌ملاحظه‌ای افزایش می‌دهد. در آیین‌نامه‌های بهسازی لرزه‌ای توصیه شده پس از بررسی کفایت اعضا و اتصالات قاب برای تحمل نیروهای حاصل از کنش میانقابی، وجود میانقاب با یک دستک فشاری قطری مدل‌سازی گردد. در مورد میانقاب‌های دارای بازشو نیز رویه مشابهی به‌کار گرفته می‌شود و در آیین‌نامه‌های بهسازی استفاده از ظرفیت آنها مجاز دانسته شده است. این در حالی است که برای مدل‌سازی آنها در سازه لازم است علاوه بر ارائه مدل ریاضی، مقدار ضریب اصلاح (m) ارائه گردد که در حال حاضر پیشنهادی برای هریک از این موارد وجود ندارد. بنابراین در این تحقیق تلاش شده است که مقدار ضریب اصلاح بر اساس کارهای آزمایشگاهی موجود در ادبیات فنی ارائه گردد. برای این منظور، مقدار این ضریب برای نمونه‌های دارای بازشو و همچنین نمونه‌های مشابه توپر محاسبه و با یکدیگر مقایسه شده است. در انتها، نشان داده شده است که ضریب اصلاح m برای میانقاب‌های دارای بازشو را می‌توان برابر با مقدار متناظر میانقاب فاقد بازشو در نظر گرفت.در ادامه ضریب اصلاح میانقاب‌های توپر مورد توجه قرار گرفت. عوامل مؤثر بر ضریب اصلاح این‌گونه میانقاب‌ها بررسی و نشان داده شد که ضریب اصلاح این‌گونه میانقاب‌ها فقط تابع جنس میانقاب و قاب پیرامون آن است و به‌رغم پیشنهاد آیین‌نامه‌ها، به نسبت بعدی و نسبت مقاومت قاب به میانقاب وابسته نیست. در ادامه مقادیری برای ضریب m میانقاب توپر برحسب جنس قاب و میانقاب پیشنهاد ‌شد.

کلیدواژه‌ها

عنوان مقاله [English]

Modification Factor of Solid and Perforated Infill Panels Based on Experimental Results

نویسندگان [English]

  • Majid Mohammadi 1
  • Alireza Sarmayekhah 2
1 Structural Engineering Research Center, International Institute of Earthquake Engineering and Seismology (IIEES), Tehran, Iran
2 Ayandegan College, Tonekabon, Iran
چکیده [English]

The infills are walls which are in full contact with surrounding frame elements. They considerably increase the stiffness and strength. It is recommended in many rehabilitation codes and guidelines to model each infill by an equivalent compression-only strut element. However, before modeling infills in the structures, adequacy of the surrounding elements and connections should be checked for the infill forces. The same procedure is proposed for perforated infill panels, the infill with large opening such as door or window. Therefore, in rehabilitation projects, the capacity of infills, both solid and perforated, can be applied against seismic loads. However, a modification factor, shown by m in many codes or guidelines such as ASCE-41 or FEMA-356, is required. The m-factors of solid infill panels have already been calculated through experimental test results and listed in the guidelines. Despite, m-factors of perforated infills have not been determined yet.
The main subject of this paper is to calculate m-factors of perforated infill panels, based on the experimental test results of the literature and comparing them with those of similar solid infills. It is shown that m-factor of a perforated infill can be assumed almost the same value of similar solid infill panel. Regarding the importance of solid infills’ m-factors, they are focused. For this, many experimental test results of solid infills are reported herein and their m-factors are calculated. It has been shown that this factor depends only on infill material and, despite FEMA-356 or ASCE-41 suggestions; it is independent of infill aspect ratio or the ratio of the frame to the infill strengths. Eventually, m-factors of some infills with different materials are suggested; the m-factors of infills with clay bricks, clay hollow bricks and hollow tiles are 2, 3.5 and 3, respectively. For infills made of concrete blocks, the m-factor is 3 for hollow blocks and 4 for solid blocks.

کلیدواژه‌ها [English]

  • Modification factor
  • Backbone Curve
  • Push-Over
  • Perforated Infills
  • Solid Infills

مراجع

  1. Office of Deputy for Strategic Supervision Department of Technical Affairs (2014) Instruction for Seismic Rehabilitation of Existing Buildings. No. 360, (in persian).
  2. ASCE/SEI Seismic Rehabilitation Standards Committee (2007) Seismic rehabilitation of existing buildings (ASCE/SEI 41-06). American Society of Civil Engineers, Reston, VA.
  3. ASCE/SEI Seismic Rehabilitation Standards Committee (2013) Seismic rehabilitation of existing buildings (ASCE/SEI 41-13). American Society of Civil Engineers, Reston, VA.
  4. Mohammadi, M. (2017) Influences of Infills on Building Structures, Sharif University Press (in Persian).
  5. Holmes, M. (1961) Steel frames with brickwork and concrete infilling. Proceedings of the Institution of Civil Engineers. 19(4), 473-478.
  6. Mallick, D. and Garg, R. (1971) Effect of openings on the lateral stiffness of infilled frames. Proceedings of the Institution of Civil Engineers, 49(2), 193-209.
  7. Mosalam, K.M., White, R.N. and Gergely, P. (1997) Static response of infilled frames using quasi-static experimentation. Journal of Structural Engineering, 123(11), 1462-4169.
  8. Polyakov, S. and Cairns, G. (1956) Masonry in Framed Buildings.
  9. Ghazimahalleh, M.M. (2007) Stiffness and damping of infilled steel frames. Proceedings of the Institution of Civil Engineers-Structures and Buildings. 160(2), 105-118.
  10. Kakaletsis, D. and Karayannis, C. (2008) Influence of masonry strength and openings on infilled R/C frames under cycling loading. Journal of Earthquake Engineering, 12(2), 197-221.
  11. Al-Chaar, G. (2002) Evaluating Strength and Stiffness of Unreinforced Masonry Infill Structures. DTIC Document.
  12. Kakaletsis, D. and Karayannis, C. (2007) Experimental investigation of infilled R/C frames with eccentric openings. Structural Engineering and Mechanics. 26(3), 231-250.
  13. Kakaletsis, D.J. and Karayannis, C.G. (2009) Experimental investigation of infilled reinforced concrete frames with openings. ACI Structural Journal, 106(2), 132.
  14. Tasnimi, A. and Mohebkhah, A. (2011) Investigation on the behavior of brick-infilled steel frames with openings, experimental and analytical approaches. Engineering Structures, 33(3), 968-980.
  15. Sigmund, V. and Penava, D. (2012) Experimental study of masonry infilled R/C frames with opening. 15th World Conference on Earthquake Engineering.
  16. Dawe, J. and Seah, C. (1989) Behaviour of masonry infilled steel frames. Canadian Journal of Civil Engineering, 16(6), 865-876.
  17. Mehrabi, A.B., et al. (1996) Experimental evaluation of masonry-infilled RC frames. Journal of Structural Engineering, 122(3), 228-237.
  18. Imran, I. and Aryanto, A. (2009) Behavior of reinforced concrete frames in-filled with lightweight materials under seismic loads. Civil Engineering Dimension, 11(2), 69-77.
  19. Sevil, T. and Canbay, E. (2010) Seismic strengthening of masonry infilled reinforced concrete frames with steel fiber reinforcement. Proceedings of the 9th US National and 10th Canadian Conference on Earthquake Engineering.
  20. Altın, S., et al. (2010) Strengthening masonry infill walls with reinforced plaster. Proceedings of the Institution of Civil Engineers-Structures and Buildings, 163(5), 331-342.
  21. Misir, S., et al. (2012) Experimental work on seismic behavior of various types of masonry infilled RC frames. Structural Engineering and Mechanics. 44(6), 763-774.
  22. Kaltakci, M.Y., Koken, A. and Korkmaz, H.H. (2008) An experimental study on the behavior of infilled steel frames under reversed-cycling loading. Iranian Journal of Science and Technology, 32(B2), 157.
  23. Flanagan, R.D. and Bennett, R.M. (1999) Bidirectional behavior of structural clay tile infilled frames. Journal of Structural Engineering, 125(3), 236-244.
  24. Parsa, F. and Moghadam, A.S. (2008) Experimental Investigation of Masonry Infilled Reinforced Concrete Frame. 681-690.
  25. Puglisi, M., Uzcategui, M. and Florez-Lopez, J. (2009) Modeling of masonry of infilled frames, Part I: The plastic concentrator. Engineering Structures. 31(1), 113-118.

فایل ها

اشتراک گذاری

ارجاع به این مقاله

آمار