• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.34 no.1
• /
• pp.95-105
• /
• 2014

Reinforced concrete (RC) shield tunnel lining must be designed for fireproof performance because the lining is sometimes exposed to very high temperature due to traffic accidents. Both experimental and numerical studies are carried out to evaluate fire resistance performance of precast RC tunnel lining systems. In the experimental studies, six full-scale precast RC tunnel segments are exposed to fire in order to examine the influence of various parameters on the fire resistance performance of precast RC tunnel lining. We used the temperature curve of the RABT criteria, which are severe conditions of fire temperatures. The fire test showed that the explosive spalling was not observed by substituting concrete to PP fiber reinforced concrete. A transient heat flow analysis was carried out in consideration of the material properties that change with temperature, and the results showed good agreement with the test results.

• Journal of Bio-Environment Control
• /
• v.31 no.4
• /
• pp.438-443
• /
• 2022

In this study, the lateral loading test was performed to analyze structural performance of multi-span plastic greenhouse through full-scale experiment and numerical analysis. In order to analyze the lateral stiffness and stress, we installed 9 displacement sensors and 19 strain gauge sensors on the specimen, respectively, and load of l mm per minute was applied until the specimen failure. In the comparison between the full-scale experiment and the structural analysis results of a multi-span greenhouse with venlo-type roof according to bracing installation, there was a large difference in the lateral stiffness of the structure. By installing a brace system, the lateral stiffness measured near the side elevation of the specimen increased by up 44%. As the bracing joint used in the field did not secure sufficient rigidity, the external force could not be transmitted to the entire structure properly. Therefore, it is necessary to establish a bracing construction method and design standards in order for a greenhouse to which bracing applied to have sufficient performance.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.04a
• /
• pp.985-988
• /
• 2008

Maglev is a system that a train runs levitated above a rail. Therefore it is very important to maintain a constant levitation gap for achieving serviceability and ride comfort. This study is a cooperation research subject of the 3-1 subject, performance improvement of maglev track structures, of the Center for Urban Maglev Program in Korea, started in 2006. The aim of this study is development of rapid constructions of bridge superstructure for maglev. At present, precast deck is widely used because of its superiority to cast-in-place concrete on quality and the term of works. The research group suggested basic systems of maglev guideway with PSC-U type and trapezoidal open steel box type girder, and precast deck, cooperating with Korea Railroad Research Institute, the managing institute of the 3-1 subject. In this study, full-scale structure was fabricated for structural safety evaluation of precast decks and rail, and a static performance test of those structures was performed.

• Journal of Korean Society of Steel Construction
• /
• v.16 no.2 s.69
• /
• pp.267-274
• /
• 2004

The objective of this study is to evaluate tensile load transmission capacity of H-shaped beam about design load by stud connector. The basic test of stud connecter was conducted and two specimens of full-scale size were tested under monotonic tensile loading condition. The parameter of tests is the size of the H-shaped beams. The results show that tensile load transmission capacity of H-shape beam about design load by stud connectors is excellent observing to the design code of steel structures of Architectural Institute of Korea.

• Journal of Korean Society of Steel Construction
• /
• v.16 no.2 s.69
• /
• pp.247-255
• /
• 2004

An experimental program was undertaken to develop seismic retrofit methods of existing steel moment connections with floor slab for improved seismic performance. Five full-scale composite specimens were tested under cyclic loading. Conventional through-diaphragm connections [please check this; no search results were found for through-diaphragm connections] composed of square-tube column and H-beam were retrofitted by adding either a bottom-flange dogbone (RBS) or an improved welded horizontal stiffener at the beam bottom flange. The effectiveness of the proposed retrofit connections schemes was evaluated. The specimen retrofitted using the RBS concept at the bottom flange showed poor connection ductility. In contrast. specimens with the proposed horizontal stiffener details exhibited improved connection ductility.

• Journal of Korean Society of Steel Construction
• /
• v.26 no.5
• /
• pp.441-452
• /
• 2014

In this paper, steel reinforced concrete(SRC) column and composite beam connections were statically tested under gravity loading. The composite beam consists of H-section and U-section members. Five full-scaled specimens were designed to investigate the effect of a number of parameters on behavior of connections such as H-section size, the presence of stud connector, the presence of stiffeners and top bars. In addition, structural performance of welded joint between the H-section and the U-section members is mainly discussed, with an emphasis on initial stiffness, strength, deformation capacity.

• Proceeding of KASS Symposium
• /
• 2008.05a
• /
• pp.145-150
• /
• 2008

The purpose of this study is to propose damper system which is easy to design, which can ensure against risks, and to verify earthquake response characteristics. For this study, the pseudo dynamic earthquake response tests carried out for steel frames with two types of seismic and vibration control device. As a result, in case of using the slit plate damper as a vibration control device proposed by this study, the damper having higher stiffness than main-structure turned to the state of plasticity by little displacement has been proved to be able to absorb earthquake energy.

• Journal of Korean Society of Steel Construction
• /
• v.19 no.5
• /
• pp.483-492
• /
• 2007

Pre-Engineering Building (PEB) system is one of the most economical structural systems. Tapered members can resist a maximum stress at a single location, whereas stresses of the rest of the members are considerably low. This results in appreciable savings both in terms of materials and construction costs. However, it was appreciated that special consideration would be required for certain aspects of this structural form. In particular, because of their slenderness, webs would buckle laterally and torsionally under the combined action of excessive axial, bending and shear forces. In this study, a total of four large-scale rafters with simple ends were tested. The main parameters were the width-thickness ratio of the web, the stiffener, and the flange brace. The purpose of this experiment is to evaluate the structural stability and to offer back-data on PEB design.

• Journal of the Korea Concrete Institute
• /
• v.19 no.3
• /
• pp.351-358
• /
• 2007

Unlike external bonded steel plate or carbon fiber, the external unbonded strengthening using hi-strength bar has some advantages in speed and simplicity of installation. It is not required surface preparations and not affected by environmental conditions. A set of nine laboratory tests on RC beams strengthened using the hi-tension bars are reported. Anchoring pin developed in former research is installed at the end of beam to connect the hish-tension bar to RC beam. The test results strengthened by hi-tension bars are compared with those of non-strengthened specimens. The main test parameters are the cross-sectional area of the high-tension bar, distance of stirrups and condition of supports. Test results show that the beams reinforced are superior to reference specimens, especially for the strength and deformation capacity. Also, shear resisting effect of hi-strength bar can be confirmed in the specimens which have lack of stirrups.

• Journal of Korean Association for Spatial Structures
• /
• v.11 no.2
• /
• pp.119-127
• /
• 2011

The purpose of this study is to propose damper system which is easy to design, which can ensure against risks, and to verify earthquake response characteristics. For this study, the pseudo dynamic earthquake response tests carried out for steel frames with metallic damper. As a result, in case of using the metallic damper as a vibration control device proposed by this study, the damper having higher stiffness than main-structure turned to the state of plasticity by little displacement has been proved to be able to absorb earthquake energy.