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Strengthening Methodology for Lightly Reinforced Concrete Frames.

pdf icon Strengthening Methodology for Lightly Reinforced Concrete Frames. (618 K)
Phan, L. T.; Lew, H. S.

Earthquake Engineering, 11th World Conference. Proceedings. Paper No. 1896. June 23-28, 1996, Acapulco, Mexico, Elsevier Science Ltd., 1-8 pp, 1996.


analytical; building technology; dynamic analysis; experimental; frames; hysteresis models; infilled walls; rehabilitation; reinforced concretes; seismic strengthening; system identification


To develop an analytical tool for assessing seismic performance of strengthened lightly reinforced concrete (LRC) frames, hysteresis failure models were developed and incorporated into computer program IDARC for dynamic analysis of LRC frames. The models were developed by, first, using the system identification techniques to characterize the load-deformation histories of LRC frame tests in terms of the stiffness degradation parameter alpha, the strength degradation parameter beta, and the pinching parameter gamma. Next, multi-variable regressions were performed to relate alpha, beta, gamma as functions of the specimen's material and geometric properties and reinforcement parameters. The empirical expressions resulting from these regression analyses are the hysteresis failure models. The models were validated against experimental results and used in a parametric study to evaluate the influence of certain variables to the behavior of infilled LRC frames. The variables included the thickness of infilled wall, the amount of reinforcement in infilled walls, and the area of anchors which connects the infilled wall to the frame. General design guidelines are proposed.