In this study, a prefabricated buckling brace (PF-BRB) was proposed, and a test specimen was manufactured based on the design formula for the initial shape and structural performance tests were performed. As a result of the experiment, all standard performance requirements presented by KDS 41 17 00 and MOE 2021 were satisfied before and after replacement of the reinforcement module, and no fracture of the joint module occurred. As a result of the incremental load test, the physical properties showed a significant difference in the stiffness ratio after yielding under the compressive load of the envelope according to the experimental results. It is judged necessary to further analyze the physical properties according to the experimental results through finite element analysis in the future.

This study develops numerical model of mega composite columns in fire and investigates the residual areas using 500℃ isotherm method and residual capacity of mega composite columns after 3 hours. In order to perform heat transfer analysis, thermal properties of steels and concrete were adopted from Eurocodes. In addition to, the temperature distributions of composite columns with respect to fire tests were compared with numerical analysis results. As a result, residual capacity of mega composite column with 1m width remained more than 45%. The residual capacity of mega composite column was only increased to 2.3∼2.6% with the use of additional rebars.

The utilization of composite columns is increasing due to the construction of high-rise buildings and large buildings. The commercially available concrete chimney steel column (ACT I) is a stable and economical structure, but there is a limit in the section size to be applied to a composite column subjected to a high load. We have developed a composite mega column with an integral structure by adding a plate to the central part of the ACT I column and installing a binding frame at a certain interval inside the central plate. In this study, to evaluate the compressive performance of the composite mega column, four test specimens were constructed with binding frame reinforcement, reinforcement spacing, and reinforced cross - sectional area. The structural performance of the composite section is compared with that of KBC2016 to evaluate the behavior of the specimen.

In this paper, a design concept of post-tensioned precast bridge piers was proposed to improve seismic behavior of the bridge pier. Mild reinforcing bars are placed continuously along the height of the column. Prestressing tendons are also provided to obtain re-centering capability for seismic events. Arrangement of the axial steels to prevent buckling of rebars at plastic hinge region was suggested and enhanced seismic performance was verified by experiments. Moment-curvature analyses were performed to evaluate the effect of effective prestress on seismic behavior after verifying the calculation method by cyclic tests of the precast columns. A real bridge pier was designed to investigate the seismic performance according to different level of effective prestress. Level of effective prestress showed obvious effect on crushing displacement but negligible effect on lateral displacement at fracture of tendons and reinforcements.

This study investigates the performance of hollow precast segmental bridge columns with reinforcement details for material quantity reduction. The proposed triangular reinforcement details are economically feasible and rational, and facilitate shorter construction periods. The precast segmental bridge columns provides an alternative to current cast-in-place systems. We tested a model of hollow precast segmental bridge columns under a constant axial load and a quasi-static, cyclically reversed horizontal load. We used a computer program, Reinforced Concrete Analysis in Higher Evaluation System Technology (RCAHEST), for analysis of reinforced concrete structures. The used numerical method gives a realistic prediction of performance throughout the loading cycles for hollow precast segmental bridge column specimens investigated. As a result, proposed reinforcement details for material quantity reduction was equal to existing reinforcement details in terms of required performance.

Recently, the using of prefabricated temporary equipments is increasing in the industrial field because it can reduce the installation and dismantling period. The various types of prefabricated temporary equipments are manufacturing with various materials in domestic and overseas countries. However, those equipments should win the safety certificate according to the "Governmental Notification about Safety Certification" which regulate the member-based safety certification. It tends to cause over performance of temporary equipments because it couldn't consider structural benefit of the prefabricated products. As the result of this study, it is concluded that the establishment of new safety certification standard for the prefabricated temporary equipments is resonable and the movable scaffold is appropriate for those prefabricated temporary equipment. The movable scaffolds are using as single structure and cannot be expands horizontally. Other types of temporary equipments are using as complex structure which can freely expand horizontally according to the main structure. From the results of the study, the standard of vertical compression performance of prefabricated movable scaffolds should be more than double the performance of single main frame. Other test items of safety certification standard should be fixed when the Notification is amended. The prefabricated temporary equipments which are adopted for the safety standard on assembled structure should be used, moved and kept in assembled state and not separated discretionally. The establishment of new standard for the assembled structure based on this study leads to the development of various types of temporary equipments using structural efficiency of prefabricated structure.

In this study, an externally reinforced structural system for SMC(Sheet Molding Compound) panel water tank, designed according to the Japanese design code, is experimented to evaluate its seismic performance. The test tank is 3m long, 2m wide and 3m high, considering the capacity and size of the shaking table. The measured hydrodynamic pressures are found to be approximately 70% of the Japanese design code values. It may be partially due to the convex shape effect of the unit panels. The analytical results of externally reinforced system based on the measured dynamic water pressures are found in good agreement with the test results. If the design hydrodynamic pressures are estimated properly, the proposed analytical model for the externally reinforced water tank becomes a useful design tool and the Japanese design code is found to provide a safe design for the external frames of SMC panel water tank.

While a wide ranges of previous researches on rapid construction of super structures are available, the studies on substructures are quite limited. The development of the precast segmental CFDST piers are briefly introduced herein and design formulas are presented for pier segment and Coping, Foundation joints. And present connect method for unit of Precast Bent Cap. The self-assembly Fabricated CFDST column is developed after the pros and cons are supplemented by the Experimental Study with the suggested connecting method.

개발된 완전 조립식 교량 하부구조에 대한 설계비교와 비선형 해석을 수행하였다. 조립식 교량 하부구조는 현행설계법과 하중저항계수설계법으로 설계하였다. 설계시에는 현 도로교설계기준에 규정된 DB-24 및 DL-24 설계활하중을 적용하였다. 이 연구는 비선형 유한요소해석을 통해서 완전 조립식 교량 하부구조의 현행 설계법인 KHBD (2005)와 AASHTO-LRFD (2007)를 평가하였다. 사용된 프로그램은 철근콘크리트 구조물의 해석을 위한 RCAHEST이다.