An investigation of linked column frame system behavior for retrofitting of RC frames

One of the newest fields of study in the field of structural and earthquake engineering is the achievement of structural systems that quickly return to their pre-earthquake state and service after an earthquake. One of the newest of these systems is the Linked Column Frame (LCF) system, which protects the vertical load-bearing system during earthquakes by having the replaceable link beam members as a fuse member. The relative low cost and easy repair process in these systems lead to the rapid return to occupancy after an earthquake. In this system, the replaceable link beams used initially provide the initial rigidity of the system and then exhibit soft nonlinear behavior and ductility with energy dissipation resulting from the yield. In this paper, the behavior of the linked column frame system for retrofitting of the RC frames in two structures of 5- and 10-storeys were investigated. Based on the results of the nonlinear static analysis of the two 5- and 10-storey reinforced concrete structures retrofitted with LCF system, the amount of bearing capacity and the energy dissipation capacity of the structure retrofitted increased by an average of 3.1 times compared to the structures without retrofitting. The plastic hinges were first formed in steel frames (LC frames) and the RC structure remained in an elastic state. Furthermore, the maximum and minimum shear absorption of seismic force percentage of the LC frames were approximately 80% and 13% in the lower and upper storeys, respectively.