In this study, retrofit improvement ratios for reinforced concrete (RC) moment frames according to the various seismic retrofit methods is investigated. The three jacketing methods (RC, steel, FRP) are considered as the seismic retrofit method. The fragility analysis is performed to evaluate the seismic performance of a structure.

Seismic performance capacity of CFT seismic retrofit method was studied through cyclic loading test. The added CFT columns share the lateral seismic force of the building with the existing RC columns to prevent building collapse. The experiment shows stable hysteric load-displacement curve.

Seismic performance capacity of CFT seismic retrofit method was studied through cyclic loading test. The added CFT columns share the lateral seismic force of the building with the existing RC columns to prevent building collapse. The experiment shows stable hysteric load-displacement curve

Recently, Earthquake occurrence in korea has become frequent, and the seismic safety of low-rise piloti buildings becomes more and more important. In this study, the seismic retrofit method of low-rise eccentric core type piloti building structures using concrete filled steel tube (CFT) columns was analysed and verified for seismic performance.

In this study, the retrofit effect of fiber reinforced plastics (FRP) jacketing by optimal algorithm for the existing reinforced concrete (RC) moment frame is investigated. FRP based retrofits are applied to both columns and beams in RC frame, simultaneously. The amounts of FRP reinforcements according to the retrofit positions are independently determined by the genetic algorithm based optimal method The amounts of FRP reinforcements and the collapse probability are considered by using the objective functions.

In this study, the retrofit effect by fiber reinforced plastics (FRP) for the existing reinforced concrete (RC) moment frames is investigated. The FRP jacketing method is employed for retrofitting the flexural strength of columns and the FRP U-shaped wrapping method are utilized for retrofitting the shear strength of beams. The placements and amount of FRP retrofit are determined by the genetic algorithm based optimal seismic retrofit algorithm.

In this study a seismic retrofit scheme for a reinforced concrete shear wall structure using steel slit dampers was presented. The stiffness and the strength of the slit damper used in the retrofit were verified by cyclic loading test. Genetic algorithm was applied to find out optimum location of the slit dampers. The effects of the slit dampers on the seismic retrofit of the model were compared with those of jacketing shear walls. The seismic performance of the model structure with optimally positioned slit dampers was evaluated by nonlinear static and dynamic analyses. Based on the analysis results, the simple procedure for determining required damping ratio using capacity spectrum method along with the damper distribution pattern proportional to the inter-story drifts was validated.

Based on the study of seismic retrofit of buildings using damper of apartment buildings, it was found that using genetic algorithm is efficient for seismic retrofit compare to existing way of retrofit. Therefore using genetic is recommended when seismic retrofit applied.

The purpose of this study is to evaluate the seismic performance of RC frame building which was retrofitted by wing walls. At fitst, the seismic performance evaluation was performed on the deteriorated RC frame building by using capacity spectrum method. And the efficiency of the retrofit by using wing walls was checked from the evaluation of its seismic capacity for various layout. As a results, it was found that the wing wall increased the stiffness and strength of the building.

This study designs RC frame specimens with existing brace retrofit system and conduct experiment. Using the resultant data, it try to analyze structural performance of the brace system and suggests preliminary data for new shape buckling-restrained braces.

The Brace retrofit system tends to be used to reinforce the non-seismic designed buildings. This study conducted several static tests to verify structural performance of the brace retrofit system. Using its resultant data, this study will propose the problems and improvements of the brace retrofit system.

The Brace retrofit system tends to be used to reinforce the non-seismic designed buildings. This study conducted several static tests to verify structural performance of the brace retrofit system. Using its resultant data, this study will propose the problems and improvements of the brace retrofit system.

Recently, retrofit by using fiber reinforced polymer (FRP) has been widely applied to building structure. However, it loose the retrofit contribution under high temperature due to fire because of its low glass transition temperature. In this manner, this paper presents a study on the development of fire resistant capacity in FRP retrofit system. Thermal transition of various fire resistant materials were verified by performing high temperature loading test. As a result, it was found that calcium silicate and alumino silicate had high resistance on the heat transition.

The previous design of the shear key is designed by considering only the strength of the anchor the body. However, the strength of the anchor portion often be influenced by steel strength of the anchor, as well as the strength of the concrete around the anchor. The purpose of this study was to improve the problem of the existing design methods by considering the performance of the shear key body and the anchor system.

To evaluate the ductility of high strength steel beam-to-column connections, Cycle loading connection test was conducted targeting HSA800 steel being developed in Korea and parameter is connection details. According to the study, The non-scallop detail and improved horizontal rib reinforcement detail used in this study enhanced deformation capacity of high strength steel connections which have brittle tendency by stress relaxation.

In this study, the optimal performance based seismic retrofit method for fiber-reinforced polymer (FRP) jackets in existing reinforced concrete (RC) frames is presented. This optimal method minimizes the amount of FRP material while satisfying the constraints on the maximum inter-story drift, maximum strain of concrete, and shear failure prevention of columns. Both of shear reinforcement for preventing shear failure of columns and flexural reinforcement for improving the flexural capacity of columns are simultaneously considered. This method is applied to 3-story RC frame and the reinforced locations and the numbers of FRP reinforcement plies are obtained.

In this study, the case of the seismic evaluation and retrofit for domestic masonry building, which are applied to the house for the aged in Busan city, was introduced. Seismic evaluation can be decided by comparing the seismic capacity index(Is) with the seismic protection index(Iso). According to the seismic evaluation, the seismic retrofit using metal lath and steel plate retrofit method was applied to the case of the lack of the seismic capacity. As a result of the retrofit, the seismic capacity was improved.

For the seismic retrofit of the underground box structures, the seismic retrofit method using pressure members was developed. By the applied pressure on the reinforcing members, the size of the reinforcing members are reduced and the performance of seismic retrofit is imp