This study utilizes an equation proposed for the calculation of the lateral-torsional buckling moment of a reinforced concrete beam to evaluate the lateral rollover stability of a precast concrete girder particularly during construction. The result of this study showed the lateral-torsional capacity of a girder significantly decreased with an increase in the initial sweep of the girder. The capacity of a girder with the initial sweep in the order of around two times the PCI tolerance becomes smaller than its ultimate flexural capacity.

In this paper, experimental study of composite slab systems was performed. The slab system could minimize reinforcements and improve crack control by applying high-ductile cementitious composites. In the application of the field construction, the construction process of the half-precast system could minimize the formwork of concrete construction.

Based on the study of chloride migration coefficient and hydration heat evolution, it was found that the use of ternary blended cement was effective to achieve desired service life and minimum crack index. On the other hand, a high level of compressive strength is required for marine concrete mix design.

This paper addresses the shear strength based on ACI 318-88 code and proposed equation by Park & Yun for steel fiber coupling beams containing steel fiber.

In this study, 3-axes controllable base isolation system is developed in consideration of mechanical performance(hysteresis and damping characteristics), maintenance and control method for ordinary submicro vibration. Also, seismic performance is evaluated by shaking table test.

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.

In this study, the seismic performance of weak-axis steel moment connections was investigated through cyclic testing of two full-scale specimens by reducing flange plate thickness. As a result, two specimens were showed that enough energy dissipation capacity and ductility.

In this study, the seismic performance of weak-axis column-tree moment resisting frame was experimentally investigated using RBS conception. As a result, two specimens were showed that enough energy dissipation and plastic rotation capacity. But bolt-slip didn’t happen anymore after story drift ratio of 3%.

The purpose of this paper is to verify the seismic strengthening effect of R/C buildings strengthened with the Carbon Fiber Composite Cable (CFCC) In this study, a three-story R/C building that constructed in the 1980s was selected, and its seismic performance before and after strengthening was evaluated based on the nonlinear dynamic analyses of members levels. The result indicated that the seismic strengthening effect of the proposed CFCC method was verified in terms of both strength and ductility demands, compared to the building before strengthening.

The purpose of this study is to evaluate seismic characteristics of medium and low-rise R/C buildings controlled by both shear and flexure. In this study, relationships between ultimate state and ductility demands of each lateral load-resisting-system were investigated based on laboratory tests.

The purpose of this study is to evaluate a RCS strengthening method for medium & low-rise R/C buildings using the nonlinear analyses of member levels. In this study, a three-story R/C buildings that represents a typical Korean school building constructed in the 1980s was selected. Seismic capacities of the building before and after strengthening with the RCS method are evaluated using the nonlinear static & dynamic analyses of member levels.

In this study, dynamic centrifuge tests on the dam interface model, which was prepared for an existing composite dam, were carried out. From the analysis of the accelerations measured at the dam base and at the crest of the concrete, the joint, and the rockfill model around the interface, the acceleration amplification characteristics of the interface was examined.

Under cyclic loading, the structural performance of reinforced concrete (RC) beam-column connections is significantly affected by the bond-slip of beam re-bars. In the present study, a bond-slip model was developed to evaluate bond-slip of beam re-bars in beam-column joints. The prediction of the proposed model agreed well with the bond strength degradation and bond-slip in the beam-column joints.

This study is about earthquake-proof reinforcement through structural function evaluation of an existing structure. The purpose of this study is to comparatively analyze structure reinforcement measures in consideration of safety and usability through structural function evaluation of existing structures, to offer rational measures for earthquake-proof function and to provide help in maintaining safe structures against earthquake. For this purpose, was selected for this study as an existing school building, earthquake-proof function evaluation was conducted, and measures to reinforce earthquake-proof function was offered. As for the research method, the first and the second earthquake-proof function evaluations were conducted which is an existing reinforced concrete school building. Through the abovementioned methods, earthquake-proof function evaluations were conducted, the results were analyzed and the measure to reinforce earthquake-proof function were offered(reinforcement brace, RC shear wall reinforcement). The offered measure to reinforce earthquake-proof function was applied to the subject structure, and comprehensive results were derived from earthquake-proof function evaluation regarding before and after earthquake-proof function reinforcement.

To investigate earthquake responses of structures with basements and soil deposits, centrifuge tests using an in-flight earthquake simulator were performed. The fixed and embedded basements did not reduce the earthquake responses of SDOF structures due to the dynamic behaviors of massive soil deposits.

To evaluate the aramid sheet and metallic damper strengthening effect of non-seismic detailed RC frame FE program, which is ABAQUS, analysis is used. Used material model of concrete, steel, rebar and aramid are concrete damaged plasticity model, steel plasticity model, perfectly plasticity model and linear fracture model, respectively. From step by step lateral load increment, the stress and crack distribution of frame and elements can be properly simulate by FE analysis.

Seismic isolation offers an attractive approach for reducing seismic loads in the building and in its components. This paper deals with the seismic isolation effects due to variation in period ratio between superstructure and isolation layer of the building. Seismic isolation effects of the moment-resisting frames with the various period ratio were studied by nonlinear time history analysis. It is recommended that the isolation period should be greater than 2.0 times of that of the superstructure for the effective seismic isolation.

Noise and vibration is the most problematic thing in the rail way bridges. In this study, we compared the vibration reduction test of two types of Spherical bearing. The results of the experiment were able to get the following conclusion. The elastomer layered spherical bearings vibration reduction performance is two times better than that of the steel type spherical bearing.

The main purpose of this study is to evaluate the seismic capacity of R/C building having masonry spandrel-walls. The pseudo dynamic test was applied in order to investigate relationships of the short column effect between a pure R/C frame and a R/C frame having masonry spandrel-walls. At the same time, the non-linear dynamic analysis was carried out and compared test results.

Recently, Seismic design criteria for major domestic structures has been being improved constantly, because the importance of seismic design for major public infrastructures is largely recognized. A preliminary assessment of the seismic performance on the existing railway tunnel, a precedent task before conducting a detailed assessment, can be use as the standard of judgement to decide whether to perform a detailed assessment or not. On the other hand, There are no reasonable study in this area. In this study, an assessment method was presented to evaluate a seismic performance of the existing railway tunnels which seismic design are not performed more economically and rationally.