Jm. Bracci et al., SEISMIC PERFORMANCE AND RETROFIT EVALUATION OF REINFORCED-CONCRETE STRUCTURES, Journal of structural engineering, 123(1), 1997, pp. 3-10
Citations number
13
Categorie Soggetti
Engineering, Civil","Construcion & Building Technology
A procedure for evaluating the seismic performance and retrofit of exi
sting low-to-midrise reinforced concrete (RC) buildings is proposed. T
he procedure is derived from the well-known capacity spectrum method a
nd is intended to provide practicing engineers with a methodology for
estimating the margin of safety against structural failure, A series o
f seismic story demand curves is established from modal superposition
analyses wherein changes in the dynamic characteristics of the structu
re at various response phases ranging from elastic to full failure mec
hanism are considered. These demands are compared to the lateral story
capacities as determined from an independent inelastic pushover analy
sis. The distribution of lateral forces used in the progressive pushov
er analysis is based on stiffness dependent incremental story shear de
mands and forms a critical aspect of the methodology. Tile proposed te
chnique is applied to a one-third scale model, three-story reinforced
concrete frame building that was subjected to repeated shaking table e
xcitations, and that was later retrofitted and tested again at the sam
e intensities. This study indicates that the procedure can provide rel
iable estimates of story demands versus capacities for use in seismic
performance and retrofit evaluation of structures.