Seismic performance evaluation of internal steel frame connection method for seismic strengthening by cycling load test and nonlinear analysis

Abstract

In this study, a seismic strengthening method by internally attaching steel frame was proposed for strengthening medium-to-low-rise reinforced concrete (RC) buildings. The main technique proposed in this study was a welding method for connecting between existing R/C frame and internal steel frame strengthening element. The connection technique was developed considering the structural integral behavior between existing frame and strengthening member. The method is one of the strength design approach by retrofit which can easily increase the ultimate lateral-load capacity of R/C buildings controlled by shear. The cycling load test, designed using an existing school building in Korea, was carried out in order to verify the seismic retrofitting effects of the proposed method in terms of the maximum load carrying capacity. The nonlinear static analysis was also conducted to establish a hysteresis model of the proposed strengthening method, and to investigate the consistency between experiment and analysis results. The results revealed that the proposed internal strengthening method installed in R/C frame enhanced conspicuously the strength capacities, and the test results can reasonably compared to those of the non-linear static analysis. © 2019 by Korea Concrete Institute.