Investigation of Soft Stories in Buildings with Hollow Block Slab

Investigation of Soft Stories in Buildings with Hollow Block Slab

Hollow block slab is a floor slab system that consists of a thin slab and joists. In hollow block slab system, nonstructural materials are used between joists. Hollow block slab usually consists of wide and shallow beams. Because of low beam height in this system, its lateral stiffness is less than beam floor systems. Because hollow block slab has low lateral stiffness, using of this slab type increases soft-story risk in buildings that have soft-story risk. Therefore, in building with hollow block slab should be detailedly investigated regarding soft-story. For this reason, in this study buildings with stores of 5, 8 and 11, which constructed with hollow block slab were numerically investigated for different ground story height. According to analysis, lateral drift ratios was obtained for each story. As ground story height increased, the lateral drift ratios of ground story with hollow block slab were increased nearly between 33% and 50%. As the number of stories increased, the lateral drift ratios have approached upper limit which is recommended by TEC-2007. The high values of lateral drift ratios in ground stories increase soft-story risk. This situation has a negative effect on building performance under lateral loads. For improving this negative effect shear walls was added to the systems and analysis was repeated. Because shear walls have decreased lateral drift ratios of ground stories nearly between 40% and 60%, negative effect of increment in ground story was decreased. It is agreed on that in high seismic zone, buildings with hollow block slab should be designed as a frame-wall system for better building performance.

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  • 1. Sezen H, Elwood KJ, Whittaker AS, Mosalam KM, Wallace JW, Stanton JF, 2000. Structural Engineering Reconnaissance of the August 17, 1999 Kocaeli (Izmit), Turkey Earthquake, PEER 2000/09, Technical Report, Berkeley, CA., Pacific Earthquake Engineering Research Center, University of California. 2. Dogangun, A., (2004). Performance of reinforced concrete buildings during the May 1, 2003 Bingol Earthquake in Turkey, Eng Struct,. 26(6): 841-856. 3. Ozturk, M., (2013). Field Reconnaissance of the October 23, 2011, Van, Turkey, Earthquake: Lessons from Structural Damages, J. Perform. Constr. Facil., 29(5): 04014125. 4. ODTU, (2011). 23 Ekim 2011 Mw 7.2 Van Depremi Sismik ve Yapısal Hasarlara İlişkin Saha Gözlemleri, METU/EERC 2011-04, Ankara. 5. SAP2000. Integrated Finite Element Analysis and Design of Structures, Computer and Structures Inc., Berkeley, California, USA. 6. IdeCAD, structure analysis software, http://idecad.com.tr/ 7. Benavent-Climent, A., X. Cahis, J.M. Vico, (2010). Interior wide beam-column connections in existing RC frames subjected to lateral earthquake loading. Bulletin of Earthquake Engineering, 8(2): 401-420. 8. Fadwa, I.,vd., (2014). Reinforced concrete wide and conventional beam-column connections subjected to lateral load, Engineering Structures, 76: 34-48. 9. Gentry, T.R., (1992). Reinforced concrete wide beam-column connections under earthquake-type loading, PhD Thesis, University of Michigan. 10. ODTU (2012). 9 Kasım 2011 Mw 5.6 Van-Edremit Depremi Sismik ve Yapısal Hasara İlişkin Gözlemler, METU-EERC / İMO 2012-01, Ankara 11. Turkish Earthquake Code (TEC), (1975). Afet Bölgelerinde Yapılacak Binalar Hakkında Yönetmelik, (Regulation for Structures in Disaster Areas), Ministry of Public Works and Settlement, Ankara, Turkey. 12. Turkish Earthquake Code (TEC), (1998). Afet Bölgelerinde Yapılacak Binalar Hakkında Yönetmelik, (Regulation for Structures in Disaster Areas), Ministry of Public Works and Settlement, Ankara, Turkey. 13. Turkish Earthquake Code (TEC), (2007). Deprem Bölgelerinde Yapılacak Binalar Hakkında Yönetmelik, (Regulation for Buildings in Seismic Areas), Ministry of Public Works and Settlement, Ankara, Turkey. 14. Domínguez, D., López-Almansa, F. and Benavent-Climent, A., (2016). Would RC wide-beam buildings in Spain have survived Lorca earthquake (11-05-2011)?, Engineering Structures, 108, 134-154 15. Arslan, M. H., and Korkmaz, H. H., (2007). What is to be learned from damage and failure of reinforced concrete structures during recent earthquakes in Turkey. Engineering Failure Analysis, 14(1), 1–22. 16. TS-500 (TSE), (2000). Requirements for design and construction of reinforced concrete structures. Turkish Standards Institution, Ankara, Turkey.