Representation of roof diaphragm in industrial buildings by hinged elastic brace pairs
Abstract
Industrial buildings are generally produced as precast. During assembly, the lower end of the columns are connected to the foundation as a fixed support. However, the upper ends of the columns connecting with the roof truss are hinged joints. Therefore, large displacements occur in the building during an earthquake. In order to prevent story drifts, column sections are taken large. However, it has been observed that the roof diaphragm of the building reduces the damages in the types of damage seen in the earthquakes experienced in recent years. The issue of including the roof diaphragm in the structure during the projecting phase has gained importance. A lot of studies have been conducted on this subject in recent years. The roof diaphragm provides the horizontal structural elements to move together in the structure. In this way, excessive displacements are prevented and it is possible to reduce the internal forces acting on the structure. Due to the relative drift limits given in TBEC-2018, larger column sections are chosen in prefabricated buildings. The rigidity of the building is increased with large column sections. However, if the rigid diaphragm behavior is applied to the building, the relative drifts are already reduced in the building.
The TBEC-2018 code provides a method for transferring seismic loads from the roof diaphragm to the vertical bearing elements. In this method, the roof covering is represented by elastic brace pairs. In this study, analysis models in which a roof diaphragm is formed with rigid diaphragm, semi-rigid diaphragm and elastic brace pairs are created. The models created were compared with parameters such as natural vibration period, base shear force, and relative drift. As a result, it has been understood that the diaphragm behavior of the structures formed by elastic brace pairs is not exactly similar a rigid diaphragm. It has been observed that the diaphragm formed by the elastic brace pairs shows similarities with the semi-rigid diaphragm.
References
[2] Terzi M, Elçi H. The influences of the slab discotinuties on the internal forces, at frame type reinforced concrete structures. Pamukkale University Engineering College Journal of Engineering Sciences 2006;12:341–9.
[3] Celep Z, Kumbasar N. Deprem mühendisliğine giriş ve depreme dayanıklı yapı tasarımı. Beta Dağıtım, İstanbul 2000.
[4] Arslan S. Effects of the slab discontinuties structural systems behavior in reinforcement buildings. 2007.
[5] Atımtay E. Çerçeveli ve perdeli betonarme sistemlerin tasarımı temel kavramlar ve hesap yöntemleri. Cilt I-II, METU Press 2000.
[6] Karadoğan F, Rutenberg A. Irregular structures, asymetric and irregular structures. İTÜ Yayınevi, İstanbul 1999.
[7] Kaplan H, Yılmaz S, Çetinkaya N, Nohutcu H, Atımtay E, Gönen H. A new method for strengthening of precast industrial structures. Journal Of The Faculty Of Engineering And Architecture Of Gazi University 2009;24:659–65.
[8] Özden Ş, Atalay HM, Akpınar E, Doyranlı B, İmren Ö. Betonarme prefarik yapıların 23 ekim 2011 Van depreminde gözlenen performansı. Beton Prefabrikasyon Dergisi 2012;103:11–9.
[9] Sezen H, Whittaker AS. Seismic performance of industrial facilities affected by the 1999 turkey earthquake. Asce Journal of Performance of Constructed Facilities 2006;20:28–36.
[10] Posada M, Wood S. Seismic performance of precast industrial buildings in turkey. 7th U.S. National Conference on Earthquake Engineering, Boston, MA.: 2002.
[11] Yılmaz S, Kuyucular A, Senel SM, Inel M. Evaluation of turkish seismic code for pinned precast concrete structures. 7th International Congress on Advanced in Civil Engineering, Istanbul, Turkey: 2006.
[12] Çetinkaya N. Prefabrik betonarme sanayi yapılarının deprem davranışının deneysel olarak incelenmesi. 2007.
[13] Turkish Seismic Code-2018 (TSC-2018) 2018.
SAP-2000. Structural analysis programs. Computers and Structures Inc, Berkeley, California 1995.
