بررسی رفتار لرزه‌ای دیوارهای برشی بتن آرمه تقویت شده با ورق‌های پلیمری مسلح ‌شده با الیاف

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشکده ‌مهندسی عمران، دانشگاه خواجه نصیرالدین طوسی، تهران، ایران.

چکیده

دیوار‌‌ برشی بتن آرمه از جمله سیستم‌های مقاوم جانبی متداول در ساختمان‌های میان‌مرتبه و بلند‌مرتبه محسوب می‌شود. بررسی رفتار ساختمان‌ها در طی زلزله‌های شدید گذشته نیز عملکرد مناسب این دیوارها را در کنترل آسیب‌های سازه‌ای و غیرسازه‌ای، به حداقل رساندن خسارات وارده و محدود کردن جابه‎جایی نسبی طبقات نشان می‌دهد. تقویت و بهسازی این عناصر می‌تواند تأثیر بسزایی در بهبود پاسخ و رفتار سازه اولیه داشته باشد. یکی از روش‎‎‎های تقویت این نوع دیوارها، استفاده از ورق‌های پلیمری مسلح شده با الیاف (FRP‌) است که امروزه به طور گسترده‌ای در بهسازی ساختمان‌ها مورد استفاده قرار می‌گیرد. مرور ادبیات فنی نشان می‌دهد که مطالعه بر روی نحوه رفتار دیوارهای برشی موجود در ساختمان‌های میان‌مرتبه و بلند‌مرتبه تحت تقویت با ورق‌های FRP بسیار کمتر از دیوارهای موجود در ساختمان‌های با ارتفاع کم (دیوارهای کوتاه) مورد توجه قرار گرفته است. به این ترتیب، در این تحقیق رفتار لرزه‌ای دیوارهای برشی بتن آرمه موجود در ساختمان‌های میان‌مرتبه و بلند‌مرتبه در اثر تقویت با ورق‌های FRP مورد بررسی قرار‌ گرفته است. دیوارهای مورد‌نظر این پژوهش شامل سه گروه دیوار با ارتفاع 16، 22/4 و 32 متری است که با استفاده از نرم‌افزار اجزاء ‌محدود ABAQUS تحت بار‌گذاری محوری و جانبی یک‌طرفه مورد تحلیل قرار گرفته و رفتار آن‌ها تحت تقویت با دو نوع ورق تقویتی CFRP و GFRP و دو نوع چیدمان ضربدری و دورپیچ افقی بررسی شده است. نتایج، افزایش ظرفیت باربری و شکل‌پذیری و جذب انرژی دیوارهای برشی بتنی میان‌مرتبه و بلند‌مرتبه را در اثر تقویت با ورق‌های FRP نشان می‌دهد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Investigation of Seismic Behavior of Reinforced Concrete Shear Walls Rehabilitated whit Fiber Reinforced Polymer Sheets

نویسندگان [English]

  • Roya Mousapour
  • Mostafa Rezvani Sharif
  • Seyed bahram Beheshti Aval
M.SC.of Structural Engineering, Faculty of Civil Engineering of K. N. Toosi University of Technology, Tehran, Iran.
چکیده [English]

Reinforced concrete shear walls are the most commonly used lateral load-resisting systems in steel and concrete buildings, especially in the case of mid- and high-rise structures. Investigations of buildings subjected to the last severe earthquakes have shown the robust performance of these walls in minimizing structural and non-structural damages besides controlling the inter-story drifts. Accordingly, strengthening of concrete shear walls, as one of the common and reliable lateral load-resisting systems in concrete structures, particularly in areas with a high risk of seismic hazard, and studying their seismic behavior are of significant importance. Strengthening, rehabilitation, and retrofit of these structural elements will have remarkable effects on the improvement of the structural response and behavior of the buildings. Using Fiber Reinforced Polymer (FRP) composite sheets is one of the practical and applicable methods for strengthening this type of wall. Nowadays, this technique is widely used as a reliable method in retrofit and renovation of buildings. In this regard, it is necessary to take a deeper look at FRP sheets and understand how they affect the seismic behavior of concrete shear walls. Indeed, civil engineers need to consider these factors in retrofitting and strengthening structural elements. Literature review on recent researches has shown inadequate study of the behavior of high-rise shear walls which strengthening with FRP layers rather than short walls. As such, in this research, the seismic behavior of high-rise shear walls reinforced by FRP layers has been studied. The main purpose of this study is to numerically model sample shear walls utilizing the Finite Elements Method (FEM) and to evaluate their seismic responses. Three types of concrete shear walls used in high-rise buildings with different heights have been modeled and analyzed using the ABAQUS commercial software. The behavior of these types of shear walls has been investigated with two types of strengthening layers (CFRP & GFRP) and two different sets and arrangements. The results showed an increase in load-bearing capacity, ductility, and energy absorption of high-rise shear walls reinforced with FRP layers.

کلیدواژه‌ها [English]

  • Concrete Shear Walls
  • High-rise shear walls
  • FRP reinforcement
  1. Lombard, J., et al. Seismic strengthening and repair of reinforced concrete shear walls. in , 12th World Conf. on Earthquake Engineering. 2000.
  2. Antoniades, K.K., T.N. Salonikios, and A.J. Kappos, Cyclic tests on seismically damaged reinforced concrete walls strengthened using fiber-reinforced polymer reinforcement. ACI Structural Journal, 2003. 100(4): p. 510-518.
  3. Paterson, J. and D. Mitchell, Seismic retrofit of shear walls with headed bars and carbon fiber wrap. Journal of Structural Engineering, 2003. 129(5): p. 606-614.
  4. Hiotakis, S., Repair and strengthening of reinforced concrete shear walls for earthquake resistance using externally bonded carbon fibre sheets and a novel anchor system. 2004, Carleton University.
  5. Elnady, M.M.E., Seismic Rehabilitation of RC Structural Walls, in Department of Civil and Environmental Engineering. 2008, PhD Thesis, McMaster University.
  6. Shaheen, I.K., Seismic Retrofit and Strengthening of Deficient Reinforced Concrete Shear Walls Using Externally Bonded Fibre Reinforced Polymer Sheets. 2014, Carleton University.
  7. Shen, D., et al., Experimental investigations on reinforced concrete shear walls strengthened with basalt fiber-reinforced polymers under cyclic load. Construction and Building Materials, 2017. 136: p. 217-229.
  8. Buyle-Bodin, F., E. David, and E. Ragneau, Finite element modelling of flexural behaviour of externally bonded CFRP reinforced concrete structures. Engineering Structures, 2002. 24(11): p. 1423-1429.
  9. Eusebio, P.P., F. Lozza, G. Manfredi, Numerical Modelling of Masonry Panels Strengthened Using FRPs. Third DIANA World Conference, Tokyo, Japan 9-11 October 2002 (Finite Elements in Civil Engineering Applications) 2002: p. 295-303.
  10. Kong, K., K. Tan, and T. Balendra, Retrofitting of shear walls designed to BS 8110 for seismic loads using FRP, in Fibre-Reinforced Polymer Reinforcement for Concrete Structures: (In 2 Volumes). 2003, World Scientific. p. 1127-1136.
  11. Mostofinejad, D. and M.M. Anaei, Effect of confining of boundary elements of slender RC shear wall by FRP composites and stirrups. Engineering Structures, 2012. 41: p. 1-13.
  12. Shadan, F., A. Khaloo, and P. Shadan, NUMERICAL STUDY ON FLEXURAL STRENGTHENING OF SQUAT RC SHEAR WALL USING FRP LAMINATES (RESEARCH NOTE).
  13. Behfarnia, K. and A. Shirneshan, A numerical study on behavior of CFRP strengthened shear wall with opening. Comput Concrete, 2017. 19(2): p. 179-189.
  14. Cornelissen, H., D. Hordijk, and H. Reinhardt, Experimental determination of crack softening characteristics of normalweight and lightweight. Heron, 1986. 31(2): p. 45-46.
  15. Lu, X., et al., Bond–slip models for FRP sheets/plates bonded to concrete. Engineering structures, 2005. 27(6): p. 920-937.
  16. Thomsen IV, J.H. and J.W. Wallace, Displacement-based design of slender reinforced concrete structural walls—experimental verification. Journal of structural engineering, 2004. 130(4): p. 618-630.
  17. S.H, Z.e.C.H., Vaghefi.M, Nonlinear Seismic Analysis of reinforced concrete shear wall with considering the effect of the interaction between concrete and rebar. Journal of Seismology and earthquake engineering, 2015. 18(2): p. 69-79. (in Persian).
  18. Khomwan, N. and S. Foster, FE MODELLING OF FRP-STRENGTHENED RC SHEAR WALLS SUBJECTED TO REVERSE CYCLIC LOADING. Proceedings of the International Symposium on Bond Behaviour of FRP in Structures (BBFS 2005), 2005.
  19. ACI-318-99, Building code requirements for structural concrete and commentary. American Concrete Institute; Detroit (MI), USA., 1999.
  20. Mohammadi Vojdan, B. and R. Aghayari, Investigating the seismic behavior of RC shear walls with openings strengthened with FRP sheets using different schemes. Scientia Iranica, 2017. 24(4): p. 1855-1865.
  21. President Deputy of Strategic Planning and Control., Instruction for Seismic Rehabilitation of Existing Building.360, Published 2014. (In Persian). 2014.
  22. Sonnenschein, R., K. Gajdosova, and I. Holly, FRP Composites and their Using in the Construction of Bridges. Procedia Engineering, 2016. 161: p. 477-482.