AN ANALYTICAL INVESTIGATION OF A BUILDING HAVING SOFT STOREY IRREGULARITY STRENGTHENED WITH CONCENTRICALLY STEEL BRACES

Year 2020, Volume: 8 Issue: 1, 91 - 102, 05.03.2020

Alptuğ Ünal

https://doi.org/10.36306/konjes.698661

Abstract

When buildings that were damaged and destroyed in major earthquakes in previous years are examined, it is seen that these buildings have several structural defects. One of these defects is that soft storey irregularity is not predicted in reinforced concrete buildings. For this reason, many buildings collapsed because of the major earthquakes, resulting in loss of life and property. Buildings stocks in earthquake zones must be inspected and buildings with the soft storey irregularity must be strengthened immediately. Also, strengthening methods are required to be quick and effective, and aesthetics of structures should not be disturbed. In this study, a 10-storey building with the soft storey irregularity is discussed. The building is strengthened with five different types of Steel Braces in various earthquake regulations in the world. The strengthening was conducted with a nonlinear analysis program and results were evaluated. According to the results, it was found that the Concentrically Steel Braces significantly increased the stiffness of the reinforced concrete building and eliminated the soft storey irregularity.

Keywords

Soft Storey, Concentrically Steel Braces, strengthening, reinforced concrete building, earthquake

Yumuşak Kat Düzensizliği Bulunan Bir Binanın Merkezi Çelik Çaprazlar ile Güçlendirilmesinin Analitik Olarak İncelenmesi

Abstract

Son yıllarda meydana gelen büyük depremlerde hasar gören ve yıkılan binalar incelendiğinde bu binaların çeşitli yapı kusurları olduğu görülmüştür. Bu kusurlardan bir tanesi de yumuşak kat düzensizliğinin betonarme binalarda öngörülmemiş olmasıdır. Bu sebeple birçok bina, büyük depremler sonucu yıkılmış ve can ve mal kaybı meydana gelmiştir. Deprem bölgelerindeki yapı stoğunun bir an önce incelenmesi ve yumuşak kat düzensizliği bulunan binaların bir an önce güçlendirilmesi gerekmektedir. Yapılacak olan güçlendirme yöntemlerinin hızlı ve etkili olmasının yanında yapının estetiğinin bozulmaması gerekmektedir. Yapılan bu çalışmada yumuşak kat düzensizliği bulunan 10 katlı bir bina ele alınmıştır. Bu bina Dünyadaki çeşitli deprem yönetmeliklerinde bulunan 5 farklı Merkezi Çelik Çapraz çeşidi ile güçlendirilmiştir. Güçlendirme işlemi bir non-lineer analiz programı ile yapılmış olup, sonuçlar değerlendirilmiştir. Elde edilen sonuçlara göre Merkezi Çelik Çaprazların betonarme binanın rijitliğini önemli ölçüde arttırdığı ve yumuşak kat düzensizliğini ortadan kaldırdığı görülmüştür.

Keywords

Yumuşak kat, Merkezi Çelik Çaprazlar, güçlendirme, betonarme bina, deprem

References

• Benavent-Climent, A. & Mota-Paez, S. (2017). Earthquake retrofitting of R/C frames with soft first story using hysteretic dampers: Energy-based design method and evaluation. Engineering Structures 137: 19-32.
• DEMC (2019).Disaster and Emergency Management Centre Turkish Earthquake Maps.
• Ebadi, P., Maghsoudi, A. & Mohamady, H. (2018). Soft story retrofit of low-rise braced buildings by equivalent moment-resisting frames. Structural Engineering and Mechanics 68(5): 621-632.
• ETABS17 (2018).ETABS v17. In
• Javadi, P. & Yamakawa, T. (2019). Strength and ductility type retrofit of soft-first-story RC frames through the steel jacketed non-reinforced thick hybrid wall. Engineering Structures 186: 255-269.
• Ju, M., Lee, K. S., Sim, J. & Kwon, H. (2014). Non-compression X-bracing system using CF anchors for seismic strengthening of RC structures. Magazine of Concrete Research 66(4): 159-174.
• Korkmaz, A. & Ucar, T. (2006). Yumuşak Kat Düzensizliğinin Betonarme Binaların Deprem Davranışında Etkisi. Uludağ Üniversitesi Mühendislik-Mimarlık Fakültesi Dergisi 11(2): 65-76.
• Lee, K. S. (2015). An Experimental Study on Hybrid Noncompression CF Bracing and GF Sheet Wrapping Reinforcement Method to Restore Damaged RC Structures. Shock and Vibration.
• Liu, X. X., Tsang, H. H. & Wilson, J. L. (2019). Seismic retrofit of precast soft-storey building using diagonal steel-shape memory alloy bracing device: Numerical investigation. Advances in Structural Engineering 22(3): 802-817.
• Mashhadiali, N. & Kheyroddin, A. (2018). Seismic performance of concentrically braced frame with hexagonal pattern of braces to mitigate soft story behavior. Engineering Structures 175: 27-40.
• Mazza, F., Mazza, M. & Vulcano, A. (2018). Base-isolation systems for the seismic retrofitting of r.c. framed buildings with soft-storey subjected to near-fault earthquakes. Soil Dynamics and Earthquake Engineering 109: 209-221.
• Mowrtage, W. (2013). Parallel Steel Frame Technique for Seismic Strengthening of Rc Structures: Case Study. Journal of Earthquake and Tsunami 7(5).
• Oinam, R. M. & Sahoo, D. R. (2018). Numerical evaluation of seismic response of soft-story RC frames retrofitted with passive devices. Bulletin of Earthquake Engineering 16(2): 983-1006.
• Oinam, R. M. & Sahoo, D. R. (2019). Using Metallic Dampers to Improve Seismic Performance of Soft-Story RC Frames: Experimental and Numerical Study. Journal of Performance of Constructed Facilities 33(1).
• Sahoo, D. R. & Rai, D. C. (2013). Design and evaluation of seismic strengthening techniques for reinforced concrete frames with soft ground story. Engineering Structures 56: 1933-1944.
• Shin, J., Scott, D. W., Stewart, L. K., Yang, C. S., Wright, T. R. & DesRoches, R. (2016). Dynamic response of a full-scale reinforced concrete building frame retrofitted with FRP column jackets. Engineering Structures 125: 244-253.
• TEC2007 (2007).Turkish Earthquake Code. 159 İzmir: Bayındırlık ve İskan Bakanlığı.
• TEC2018 (2018).Turkish Earthquake Code. 395 Ankara: TMMOB İnşaat Mühendisleri Odası.
• Thinley, K. & Hao, H. (2017). Seismic response analyses and performance assessment of masonry-infilled reinforced concrete frame buildings in Bhutan without and with soft storey. Advances in Structural Engineering 20(5): 822-839.
• Unal, A. & Kaltakci, M. Y. (2016). Seismic behavior of concentrically steel braced frames and their use in strengthening of reinforced concrete frames by external application. Steel and Composite Structures 21(4): 687-702.
• Varum, H., Teixeira-Dias, F., Marques, P., Pinto, A. & Bhatti, A. (2013). Performance evaluation of retrofitting strategies for non-seismically designed RC buildings using steel braces. Bulletin of Earthquake Engineering 11(4): 1129-1156.
• Yon, B. & Sayın, E. (2011).Betonarme Perdeler ve Çelik Çaprazlarla Yapılan Güçlendirmelerin Karşılaştırılması In 6th International Advanced Technologies Symposium (IATS’11), 237-242 Elazığ, Turkey.