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Shake table responses of an RC low-rise building model strengthened with buckling restrained braces at ground story

  • Lee, Han Seon (School of Civil, Environmental, and Architectural Engineering, Korea University) ;
  • Lee, Kyung Bo (School of Civil, Environmental, and Architectural Engineering, Korea University) ;
  • Hwang, Kyung Ran (School of Civil, Environmental, and Architectural Engineering, Korea University) ;
  • Cho, Chang Seok (WISE Structural Engineering Co. Ltd.)
  • Received : 2013.01.08
  • Accepted : 2013.10.26
  • Published : 2013.12.20

Abstract

In order to verify the applicability of buckling restrained braces (BRB's) and fiber reinforced polymer (FRP) sheets to the seismic strengthening of a low-rise RC building having the irregularities of a soft/weak story and torsion at the ground story, a series of earthquake simulation tests were conducted on a 1:5 scale RC building model before, and after, the strengthening, and these test results are compared and analyzed, to check the effectiveness of the strengthening. Based on the investigations, the following conclusions are made: (1) The BRB's revealed significant slips at the joint with the existing RC beam, up-lifts of columns from RC foundations and displacements due to the flexibility of foundations, and final failure due to the buckling and fracture of base joint angles. The lateral stiffness appeared to be, thereby, as low as one seventh of the intended value, which led to a large yield displacement and, therefore, the BRB's could not dissipate seismic input energy as desired within the range of anticipated displacements. (2) Although the strengthened model did not behave as desired, great enhancement in earthquake resistance was achieved through an approximate 50% increase in the lateral resistance of the wall, due to the axial constraint by the peripheral BRB frames. Finally, (3) whereas in the original model, base torsion was resisted by both the inner core walls and the peripheral frames, the strengthened model resisted most of the base torsion with the peripheral frames, after yielding of the inner core walls, and represented dual values of torsion stiffness, depending on the yielding of core walls.

Keywords

reinforced concrete;irregular;earthquake simulation test;torsion;buckling-restrained brace

Acknowledgement

Supported by : National Research Foundation of Korea

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Cited by

  1. Torsion design implications from shake-table responses of an RC low-rise building model having irregularities at the ground story vol.44, pp.6, 2015, https://doi.org/10.1002/eqe.2492
  2. Structural behavior of conventional and buckling restrained braced frames subjected to near-field ground motions vol.7, pp.4, 2014, https://doi.org/10.12989/eas.2014.7.4.553
  3. Seismic Damage to RC Low-rise Building Structures Having Irregularities at the Ground Story During the 15 November 2017 Pohang, Korea, Earthquake vol.22, pp.3, 2018, https://doi.org/10.5000/EESK.2018.22.3.103