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The use of carbon reinforced polymer (CFRP) to provide lateral confinement for enhanced ductility and strength of reinforced concrete structures has been increasing. The present study, attempts to analytically investigate the effect of the layout of frame columns retrofitted with different layers of CFRP on the seismic performance and damage potential of structures under strong ground motion using realistic and efficient computational models. Based on the shaking table tests of several reinforced concrete (RC) flat slab beamless construction models, the seismic performance of structures strengthened with CFRP composites are investigated. The dynamic response of CFRP retrofitted structures and the components of the model, validation of the model, force-displacement relationship, relative displacement and the time history curves are studied. Then the rational effect of different CFRP layers is found.

Abstract-Intensity measure (IM) is a parameter that is used to scale the records for the time-history analysis of a structure subjected to seismic loads. It is well known that the accuracy of the seismic response of the structure depends very much on IM. This paper presents a study on the use of the inelastic displacement as IM for the nonlinear time-history analysis. For the purpose of the study, three reinforced concrete moment-resisting frame buildings (4-, 10-, and 16-storey high) designed for Vancouver, Canada were used in the analysis. The buildings were subjected to the total number of 40 records scaled to five intensity levels which represent a global ductility of 1 to 5. Based on the results from the analysis, it was found out that the inelastic displacement does not have advantage over the elastic displacement (or the spectral acceleration) as IM.Index Terms-Dispersion, elastic displacement, inelastic displacement, intensity measure. I. MOTIVATIONThere are several studies in which the inelastic spectral displacement at the fundamental structural period, T 1 (i.e., Sdi(T 1 )), has been used as an intensity measure (IM), e.g. [1], [2]. For a given building, the inelastic spectral displacement (Sdi) is computed for an equivalent bilinear single-degree-of-freedom (SDOF) system that has the same elastic period as the fundamental period of the building, and provides displacement responses to ground motions that are similar to the roof displacements of the building. The same as Sa(T 1 ), Sdi does not include the contributions of the higher modes to the response of the structure. However, Sdi is intended to take into account the effects of the elongation of the fundamental period during nonlinear response. This is because the period of the equivalent SDOF system elongates during the response, and therefore Sdi depends, to some extent, on the ground motion spectral characteristics for periods longer than the elastic period of the SDOF system.The objective of this study was to assess the potential use of Sdi as IM. This was done by investigating the seismic responses of three reinforced concrete frame buildings (4-, 10-, and 16-storey high) located in Vancouver, Canada subjected to a selected set of records scaled to different intensity levels. The dispersions of the interstorey drifts resulting from Sdi were compared to those from Sde (elastic spectral displacement) to know the suitability of using Sdi as IM for the seismic analysis of buildings. Note that the elastic spectral displacement (Sde) for a given period, T 1 , is linearly proportional to the elastic spectral acceleration (Sa) for that period (i.e., Sde = (T 1 /2π) 2 ·Sa), and therefore, Sde and Sa represent the same IM. For convenience, however, Sde rather than Sa is used in this study. Engineering and Technology, Vol. 6, No. 6, December 2014 II. DESCRIPTION OF BUILDINGS AND DESIGN PARAMETERSThree reinforced concrete frame buildings, 4-, 10-, and 16-storey, were used in the study (Fig. 1). The buildings are for office use and are located in Van...