• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1992년도 가을 학술발표회 논문집
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• pp.208-213
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• 1992

This research is related to the experimental verification of the shear resistance of horizontal joint in precast concrete large panel structures. a total of 9 spicemens was tested to assess their shear resistance. In the tests lateral forces have been applied to the specimen to cause shear failure while keeping the axial compression consistantly. The shear resistances of the specimens have been evaluated by investigating the deformations and failure modes of the specimens. From the test results, it is observed that the shear resistance of the horizontal joints of P.C panel structures are closely connected with shear friction mechanism.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1992년도 가을 학술발표회 논문집
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• pp.179-184
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• 1992

Four 3-story 1/2 scaled large concrete panel structures were designed and tested to estimate the seismic resistance capacity of large concrete panel high rise building systems, Test specimens were modeled three story of 24 or 15 story buildings and set up to represent the actural stress of the building . The axial force was constant and the horizontal force was loaded by ductility ratio. Results indicated that the joints of specimens were behavied monolithically to maximum strength. It was shown that the joint box connecting system had lower maximum strength and energy dissipation capacity than welding connection system, but had better deformation capacity.

• 콘크리트학회지
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• 제3권2호
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• pp.133-145
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• 1991

The essential difference between precast concrete structures and in situ concrete structures lies in the precast concrete panel structres, it is necessary to understand the bahavior of joints and their implications regarding overall structural behavior. Form such a point of view, this experimental study observes the components and joint behavior under the stress states expected of precast concrete panel structures subjected to lateral loads. 2 full-scale subassemblages were fabricated and tested. The test results show that the characteristics of horizontsl joints and wall coupling beams mainly govern the whole hahavior of P.C. structres.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1990년도 가을 학술발표회 논문집
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• pp.73-78
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• 1990

Large panel building systems are composed of vertical wall panels which support horizontal roof and floor panels to form a box like structure. The simplecity of the connections, which makes precast concrete economically viable, causes a lack of continuity in stiffness, strength and ductility. This precast concrete large panel systems typically have weak connection regions. Three types of 2-story full-scale precast concrete subassemblages were tested under reversed cyclic loading. The seismic resistance capacity and failure mode of each system are compared in connection with the characteristics of joint connection details.

• 한국구조물진단유지관리공학회 논문집
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• 제3권3호
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• pp.261-268
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• 1999

The seismic performance of precast concrete panel structures tested previously has been evaluated in this paper. Hysteretic curves of test specimens are idealized to elasto-plastic curves to get reliable yielding and ultimate displacements. For the idealized curves, ductility and energy dissipation capacity of specimens have been evaluated using a few guide lines. In addition, the strength capacity of specimens is checked for the strength demand caused by the design earthquake load including overturning moment effects. The result shows while the strength of specimen with joint box for vertical continuity is little bit lower than that of specimen connected by welding, the ductility of the former is higher than that of the latter. The energy dissipation ratios of PC specimens are ranged from 83% to 96% of that of Re specimen and the average of those are shown 90%.

• 한국공간구조학회지
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• 제23권4호
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• pp.4-9
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• 2023

• Earthquakes and Structures
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• 제19권5호
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• pp.315-329
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• 2020

Through bolt connections in Concrete Filled Steel Tubes (CFSTs) has been proved to be good in terms of seismic performance and constructability. Stiffened extended end plate connection with full through type bolt helps to avoid field weld altogether, and hence to improve the quality of joints. An experimental study was conducted on the hysteretic performance of square interior beam-column connections using flat extended end plates with through bolt. The study focuses on the effect of the bond between the tie rod and the core concrete on the cyclic performance of the joint. The study also quantifies how much the interior joint is getting strengthened due to the confinement effect induced by bi-directional bolting, which is widely used in 3D moment resisting frames. For a better understanding of the mechanism and for the prediction of shear capacity of the panel zone, a mathematical model was generated. The various parameters included in the model are the influence of axial load, amount of prestress induced by bolt tightening, anchorage, and the concrete strut action. The study investigates the strength, stiffness, ductility, and energy dissipation characteristics. The results indicate that the seismic resistance is at par with American Institute of Steel Construction (AISC) seismic recommendations. The bidirectional bolting and bond effect have got remarkable influence on the performance of joints.

• 대한건축학회논문집:구조계
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• 제35권9호
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• pp.151-158
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• 2019

A concrete core is used widely as lateral stability systems in high-rise modular buildings. As an alternative to traditional cast in-situ core, the precast concrete(PC) method can accelerate the construction of reinforced concrete cores. A core composed of precast elements differs from a in-situ core in having connections between the precast elements. The typical vertical connection between PC panels is consisted of shear keys, loop bars, lacer bars and grout. In this study, the effect of vertical connection components on shear strength is investigated experimentally. The test results show that the contribution to the shear strength is greater in order of grout strength, shear keys, lacer bars and loop bars. In addition, the numerical models to estimate the shear strength according to two crack patterns in the vertical joint of the PC panels are derived. The feasibility of the numerical models is evaluated by comparing the estimated shear strength and the test results.

• 근관절건강학회지
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• 제27권3호
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• pp.325-332
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• 2020

Purpose: This study attempted to classify the potential layer for pain in the middle-aged and elderly based on the seventh Aging Research Panel Survey (2018) data and to identify the degree of depression by potential layer. Methods: This study used data from the 2018 Aging Research Panel Survey, whose participants included 6,890 middle-aged and elderly people. The data were analyzed using SPSS/WIN 22.0 and M-plus 8.0 for latent profile analysis. Results: In the study, Type 1 was a "general pain group", Type 2 was the "high back pain group", Type 3 was the "lower body pain group", Type 4 was the "shoulder pain group", and Type 5 was the "pain-free group", which included those who answered that there was no pain. Second, it was found that the variables such as gender, age, education, or not alone were statistically significant (p<.001). Third, the difference in income, subjective health conditions, depression according to the pain site type group were confirmed. Depression was significantly higher in the back pain group, lower body pain group, and shoulder pain group compared to the pain-free group. Conclusion: Developing integrative interventions is necessary to reduce depression using the pain coping skills in middle-aged and Elderly.

• Steel and Composite Structures
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• 제1권3호
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• pp.295-312
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• 2001

The purpose of this paper is to propose a new type of steel reinforced concrete (SRC) beam-column joints and to examine the structural performance of the proposed joints, which simplify the construction procedure of steel fabrication, welding works, concrete casting and joint strengthening. In the proposed beam-column joints, the steel element of columns forms continuously built-in crossing of H-sections (${\Box}$), with adjacent flanges of column being connected by horizontal stiffeners in a joint at the level of the beam flanges. In addition, simplified lateral reinforcement (${\Box}$) is adopted in a joint to confine the longitudinal reinforcing bars in columns. Experimental and analytical studies have been carried out to estimate the structural performance of the proposed joints. Twelve cruciform specimens and seven SRC beam-column subassemblage specimens were prepared and tested. The following can be concluded from this study: (1) SRC subassemblages with the proposed beam-column joints show adequate seismic performances which are superior to the demand of the current code; (2) The yield and ultimate strength capacities of the beam-to-column connections can be estimated by analysis based on the yield line theory; (3) The skeleton curves and the ultimate shear capacities of the beam-column joint panel are predicted with a fair degree of accuracy by considering a simple stress transfer mechanism.