Title: Multistory Reinforced Concrete Frames Under Simulated Seismic Loads

Author(s): A. H. Chowdhury and R. N. White

Publication: Symposium Paper

Volume: 63

Issue:

Appears on pages(s): 275-300

Keywords: beams (supports); cyclic loads; ductility; earthquake resistant structures; frames; framing systems; lateral pressure; loads (forces); models; multistory buildings; reinforced concrete; stiffness; stiffness methods; tests.

DOI: 10.14359/6655

Date: 8/1/1980

Abstract:
Two three-story, two-bay l/10 scale reinforced concrete model frame structures were subjected to combined gravity and lateral loads. One frame was subjected to unidirectional lateral loading, and the second was loaded with gradually increasing reversing lateral loads; loads were increased to failure in both cases. Distribution of lateral loads was in accordance with the SEAOC requirements for seismic design; steel reinforcement was also designed to conform to these requirements. A nonlinear, incremental stiffness analysis approach was developed for uni-directional loading and was applied to the experimental frame and to a single bay portal frame reported in the literature. Stiffness reduction of the frame subjected to reversing lateral loads was not more severe than that for the unidirectionally loaded frame at loads less than about 80% of the ultimate lateral load capacity of the frame. There was minor reduction in strength and stiffness caused by cycling at higher load levels. Ductility requirements were met by the frames, and no adverse shear-induced effects were observed in the joint regions of the frames. The analytical method gave excellent predictions of frame deformations.