A NUMERICAL AND ANALYTICAL STUDY ON OPTIMIZATION AND EFFICIENCY OF STRUCTURAL FORMS BY TWO-OUTRIGGER IN TALL BUILDINGS
DOI:
https://doi.org/10.11113/mjce.v28.16006Keywords:
Outrigger systems, tall buildings structure, FEA method, lateral resistance system, pushover analysisAbstract
The selection of a suitable structural system and resist lateral loads in tall buildings plays an important role in structural design. The increase of the heights in the high-rise buildings will be limited because of exceed drift due to lateral loads. The outrigger systems always have been the best choice to limit the lateral deflections in slender buildings. This paper presents analytical and numerical methods to determine optimum location of the outriggers through the height of the building. Optimization and efficiency of the outriggered structural systems were examined in the reduction of the top drift. In the analytical method was used an idealized model as Two- Dimensional (2D) due to horizontal loads. In this regard, Three-Dimensional (3D) building frames were simulated as numerical method by Abaqus/CAE program. Two types conventional forms of the outrigger systems were considered as lateral resisting systems. The numerical models were utilized two outriggers as forms of (a) and (b). Pushover analysis was conducted under uniformly lateral load that was distributed throughout the height. The obtained results by the 2D analytical method shows that the model of the form (a) was optimized when the second outrigger located at 0.58H from the top of the structure while the first outrigger was fixed at the top, in the form (b) was optimized where the outrigger levels were placed at 0.31H and 0.69H, from the top of the building. The results of the 3D modelling by Finite Element Analysis (FEA) indicated that in the form (a) in which the first outrigger is fixed at the top and the second outrigger is optimized at 0.55H from the top of the model. In this way, two outrigger levels of the form (b) were optimized at 0.29H and 0.62H from the top of the structure. The efficiency of the optimized two forms of the outrigger systems in the reduction of the lateral drift at the top of the building by numerical modelling were determined; the efficiency of the outriggers system form (b) is 42% higher than optimized model of the form (a). The 3D Finite Element Analysis (FEA) method for use in the initial design of an outrigger structural system in tall buildings is recommended because of reliable results in compared to the 2D theoretical analysis in order to an optimum design of tall buildings structure.References
Alpana L. Gawate, J. P. B. (2015). behavior of outrigger structural system for high rise building.
International Journal of Modern Trends in Engineering and Research (IJMTER). 2(7).
ATC (1996). redwood city, California: applied technology council (report no 40).
Fawzia, S. and Fatima, T. (2010). Deflection control in composite building by using belt truss
and outriggers system. Proceedings of the 2010 Proceedings of the 2010 World
Academy of Science, Engineering and Technology conference,
FEMA-273 (1997). Washington D.C: developed by the building seismic safety council for the
federal emergency management agency.
FEMA-356 (2000). volume 1. redwood city, California: applied technology council (report no
.
Ghosh, S. K., Fanella, D. A. and Rabbat, B. G. (1996). Notes on ACI 318-95, Building Code
Requirements for Structural Concrete: With Design Applications. Portland cement
association.
Goel, R. K. (2005). Evaluation of modal and FEMA pushover procedures using strong-motion
records of buildings. Earthquake spectra. 21(3), 653-684.
Günel, M. H. and Ilgin, H. E. (2014). Tall Buildings: Structural Systems and Aerodynamic Form.
Routledge.
Herath, N., Haritos, N., Ngo, T. and Mendis, P. (2009). Behaviour of outrigger beams in high rise
buildings under earthquake loads. Proceedings of the 2009 Australian Earthquake
Engineering Society 2009 Conference,
Hoenderkamp, J. (2008). Second outrigger at optimum location on high†rise shear wall. The
structural design of tall and special buildings. 17(3), 619-634.
Kamath, K., Divya, N. and Rao, A. U. (2012). A Study on Static and Dynamic Behavior of
Outrigger Structural System for Tall Buildings. Bonfring International Journal of
Industrial Engineering and Management Science. 2(4), 15.
Samat, R. A., Ali, N. M. and Marsono, A. K. (2008). The Optimum Location of Outrigger in
Reducing the Along-Wind and Across-Wind Responses of Tall Buildings. Malaysian
Journal of Civil Engineering. 20(2).
Smith, B. S. and Coull, A. (1991). Tall building structures: analysis and design. University of
Texas Press.
Smith, B. S. and Salim, I. (1983). Formulae for optimum drift resistance of outrigger braced tall
building structures. Computers & Structures. 17(1), 45-50.
Standard, A. (2004). E8-04,“. Standard Test Methods for Tension Testing of Metallic Materials,â€
Annual Book of ASTM Standards. 3.
Zeidabadi, N. A., Mirtalae, K. and Mobasher, B. (2004). Optimized use of the outrigger system
to stiffen the coupled shear walls in tall buildings. The structural design of tall and
special buildings. 13(1), 9-27.
