• Journal of Korean Society of Steel Construction
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• v.19 no.5
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• pp.527-537
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• 2007

The main girders and cross-beams of an H-beam bridge consisted of factory-made H-beams, providing better conditions for quality control. Also, on-site fabrication works can be minimized and most of the stiffeners can be omitted, enabling simple and economic construction. In this study, the effect of the Multi-Stepwise TPSM (M-TPSM) on improving the maximum span length and section efficiency is analyzed. Compared to a 30-m-long, five-girder conventional plate girder bridge, structural analysis results showed that 50.7~55.1% of the girder height and 24.1~26.2% of the self-weight may be reduced by the application of M-TPSM to a five-girder H-beam bridge constructed with H-$900{\times}300$beams. In case of conventional H-beam bridges without M-TPSM, it was found that seven girders are required for a similar level of load-carrying capacity. Therefore, it is concluded that by the application of the M-TPSM, the H-beam bridge would become one of most cost-competitive options for short- and medium-span bridges.

• Journal of Korean Society of Steel Construction
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• v.25 no.5
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• pp.531-541
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• 2013

This paper investigated the structural capacity of the CT shear connectors, which is a kind of the perfobond rib and functions as an anchor transferring the tension force in the joint between a composite PHC wall pile and a bottom slab. The direct pull-out test was performed for various specimens. From failure modes and load-displacement curves, it was found that transverse rebars should be placed to holes in a web to restrict pull-out failure of CT shear connectors. The results of additional tests for specimens with transverse rebars and various support lengths indicated that all specimens were failed by the tension failure of PHC pile before pull-out failure of CT shear connector and concrete pull-out failure. Thus, the CT shear connector could endure the tension force between the PHC wall pile and the bottom slab.

• Journal of Korean Society of Steel Construction
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• v.24 no.2
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• pp.233-243
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• 2012

This study verifies the structural capacity of the composite PHC pile (Pretensioned spun high-strength concrete) consisting of a PHC pile and two CT structural steels. Four full-scale specimens are fabricated and the experimental tests were performed to investigate the flexural behaviors of the composite PHC piles. The composite PHC pile can enhance both the structural capacity and functional convenience, since the web of CT structural steel with holes in the web acts as a shear connector (referred to as the perfobond rib), which can connect concrete and steel. All specimens exhibited flexural failure and the ultimate strengths were larger than the anticipated design strength according to the design standard. Thus, the composite PHC pile can be applicable to wall structures with sufficient strength. In addition, it seems that the web of the CT structural steel with holes performs its role as shear connectors.

• Journal of Korean Society of Steel Construction
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• v.27 no.2
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• pp.231-241
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• 2015

The direct strength method (DSM) has been adopted by the NAS (2004) and AS/NZS 4600 (2005) for the design of cold-formed steel members. The method can be successfully applied to the design of welded steel members. This paper reviews the development of the DSM for welded steel structural members. The design strength formulae for welded section columns and beams for the DSM are based on the test results performed on welded H-section, C-section, circular and rectangular hollow section columns, plate girders and stiffened plates. The comparison between the design strength of welded sections predicted by the DSM and that estimated by existing specifications is also provided. The comparison verifies that the DSM can properly predict the compressive, flexural and shear strength of welded section columns and beams with the interaction between local and overall buckling.

• Journal of Korean Society of Steel Construction
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• v.20 no.6
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• pp.829-838
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• 2008

In this study, cyclic tests of beam-column connections composed with members applicable to the domestic low-middle rise steel buildings were conducted to develop seismic connection details and its evaluation. Connection types and material properties of the steel were testing variables and the difference between the newly developed seismic rolled section (SHN490) and existing rolled section (SM490) was also investigated. Distributions of the yield strength and the ultimate strength of the SHN490 rolled section were relatively uniform comparing to those of the SM490 rolled section Brittle fracture in the weldments of the test specimens was not observed. Instead, fracture occurred at heat-affected zones or the stress-concentrated point near the weld access hole of the beam flanges. In the case of identical rolled-section specimens, the rotational capacity and dissipated energy of the WUF-W connection was larger than those of the WUF-B connection. In the case of identical connection types, the rotational capacity and dissipated energy of the SHN490 section connection was larger than those of the WUF-B section connection.

• Journal of Korean Society of Steel Construction
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• v.15 no.2
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• pp.109-116
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• 2003

An investigation on the structural behavior of cold-formed steel lipped C-section stud for interior walls or partitions was carried out. This experimental research was carried out to study the ultimate and service load capacity of stud assemblies that are subjected to lateral loads. Each test specimen consisted of three or four lipped C-section studs and two C-section tracks that restrained both ends. The major factors considered in this experiment were the perforation on the web, the connection of the bridge channel and the special clip. The effect of the plaster board and the ply wood, which were attached to the tension flange on the flexural strength, was also investigated. Thereafter, the test strength capacities were compared with the nominal strength, based on the AISI Specifications (1996).

• Journal of Korean Society of Steel Construction
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• v.24 no.2
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• pp.199-206
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• 2012

Unstiffened seated connections (USC) ensure easy installation and safety during erection, thereby making the process more economical. USCs consist of a seat angle for carrying the beam's reactions and a top angle to provide beam stability. These angles are bolted or welded to the beam and supporting member. This paper sought to propose a design table for the weld strength of such connections obtained from the elastic vector method (EVM) and the instantaneous center-of-rotation method (ICM) in terms of calculating the eccentricity. Also, the proposed design table is compared with both AISC and KBC specifications.

• Fire Science and Engineering
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• v.25 no.5
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• pp.76-84
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• 2011

Steel beams are one of primary member and those carries the horizontal load and floor load to axial member. To avoid structural failure when the steel beams are exposed to fire, fire resistance performance requires. Till now, the evaluation for fire resistance of the beam was conducted using the maximum load and standard fire curve defined in the KS F 2257. But recently the constructional patterns are changing toward multi-function performance to get a better structural performance and fire resistance as well. In this paper to get the databases for fire resistance, limiting temperatures of the beam, load-bearing fire tests according to load ratios, two grades of compressive concrete strengths were applied.

• Journal of Korean Society of Steel Construction
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• v.17 no.1 s.74
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• pp.83-92
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• 2005

This paper is to evaluate the load carrying capacities of cold-formed steel columns subject to combined axial load and bending moment. A combined strength experiment is carried out using full-scale 24 specimens of lipped channel section with embossment in web. An eccentric axial load is applied in varying member-length and eccentric distance which produces an end-moment of the column. The predictions of the AISI specification and the Eurocode are compared with the experimental results, and it is shown that all of these codes are reasonable on the whole in relation to the experimental results.

• Fire Science and Engineering
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• v.22 no.2
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• pp.84-90
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• 2008

This paper aims to experimentally investigate the in-fire performance of composite beams with respect to the effects of load ratio and shear interaction. Under a Standard ISO834 fire, the development of temperature and deflection of simply supported composite beams were recorded. In particular, the transition of temperature distribution across the cross-section. The fire resistance of composite beam was interpreted regarding the level of shear interaction.