Strengthening Methodology for Lightly Reinforced Concrete Frames.
Strengthening Methodology for Lightly Reinforced
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.