Title:
Seismic Response of Reinforced Concrete Frames with Strength and Stiffness Irregularities
Author(s):
Yong Lu, T. P. Tassios, G.-F. Zhang, and Elizabeth Vintzileou
Publication:
Structural Journal
Volume:
96
Issue:
2
Appears on pages(s):
221-229
Keywords:
earthquakes; frames; models; reinforced concrete
DOI:
10.14359/613
Date:
3/1/1999
Abstract:
Two six-story, three-bay, reinforced concrete frames, one having a tall first story (BF1), and the other a discontinuous interior column (DCF), were designed in accordance with Eurocode 8, and their 1:5.5-scale models were constructed and tested on an earthquake simulator. The main objectives of the investigation were to study the structural effects of these particular irregularities and to check the relevant designcode provisions. During tests, Frame BF1 performed in a reasonably regular manner. For Frame DCF, the response during moderate earthquakes was strongly influenced by the increased flexibility in the direction towards the missing column side, combined with the gravitational effects on the suspended beam spans. The response of Frame DCF to strong earthquakes was dominated by an apparent soft first-story mechanism. Both frames exhibited a weakness at the fifth story where discontinuity in stiffness occurred. A base shear overstrength factor, with respect to the design- required base shear, approximately of the order of three and two, was achieved for Frames BF1 and DCF, respectively.