• Journal of Korean Society of Steel Construction
• /
• v.13 no.6
• /
• pp.621-629
• /
• 2001

This study consists of static and fatigue tests to evaluate the behavior on the field splice joint of longitudinal rib in orthotropic steel deck specimens. Specifically, static and influence surface tests are performed for the stress distribution at the scallop area and high-strength bolt connection of longitudinal rib to examine the existence of handhole cover plate and the effect of eccentric loads. The ultimate strength of the field splice joint of longitudinal rib is obtained. In fatigue tests, cracks are observed at the scallop in the lower level test and the catastrophic failure of longitudinal rib is occurred following the failure of handhole cover plate in the higher level test. This study gives a basis for the better understanding of the field splice joint of longitudinal rib.

• Journal of Korean Society of Steel Construction
• /
• v.15 no.3
• /
• pp.313-320
• /
• 2003

The governing equation of the post-buckling of shear-deformable uniform columns under a combined load consisting of a uniformly distributed axial load and a concentrated load at a free end was derived and the post-buckling analysis was investigated by using differential transformation. The loads were obtained for various end-slopes. The results obtained by the present method agree well with published results. In this paper, the differential transformation method was illustrated through its application to the non-linear differential equation of the post-buckling. It is expected that applications of the method to more challenging problems will are expected follow in future to ensue.

• Journal of Korean Society of Steel Construction
• /
• v.15 no.5 s.66
• /
• pp.551-559
• /
• 2003

In steel frames, the analysis and design techniques are based on either idealized fixed or pinned connections. In this case, it has the advantage that the structural analysis and the design procedure were simplified, but there could be given different results of analysis between the real steel frame connections and the idealized fixed and pinned connection. This is because the real connections would be analyzed by semi-rigid, and have some transfer of moment and rotational constraint about the loads. In this study, structural analysis program with considered connections that have joint rigidity of fixed, pinned and semi-rigid, was developed. Then, the effects of joint rigidity on strength and displacement. in steel frames subjected to lateral forces and axial forces, were investigate, and the results were compared with those of the Midas Gen. w program.

• Journal of Korean Society of Steel Construction
• /
• v.19 no.1
• /
• pp.53-65
• /
• 2007

Column tests were performed for a new type of column, the internally confined hollow concrete filled tube column (ICH CFT column), to evaluate its seismic performance. The seismic performances for two types of ICH CFT columns and a general solid RC column were evaluated and compared by quasi-static tests. The displacements and the lateral loads of column specimens were measured during tests. Ductilities, absorbed energy, equivalent damping ratios, damage indices were calculated from recorded data. From the test results, the ICH CFT column shows superior seismic performances with double moment capacity and larger energy absorbing capacity over that of a solid RC column.

• Journal of Korean Society of Steel Construction
• /
• v.19 no.1
• /
• pp.87-98
• /
• 2007

Generally, main girders and steel piers of temporary bridges form the steel rahmen structure. In this study, the rational stability design procedure for main members of temporary bridges was presented using a 3D system buckling analysis and second-order elastic analysis. Six types of temporary bridges, which can be designed and fabricated in reality, were chosen and the buckling design for them was performed in consideration ofload combinations of dead and live loads, thermal load, and wind load. Effective buckling length of steel piers, transition of 3D buckling modes, and effects of second-order analysis were investigated through a case study involving six temporary bridges.

• Journal of Korean Society of Steel Construction
• /
• v.12 no.4 s.47
• /
• pp.407-416
• /
• 2000

This paper presents the dynamical responses of the plate girder bridge subjected to moving load by experimental method. The upper slab of the plate girder bridges is modelled to the plate element and the girder to the beam element. The small-scaled vehicle model is manufactured as moving load and the acryl-bridge model as the plate-girder bridge. The dynamic responses of the plate-girder bridges under the moving load are obtained by the strain gauges, displacement measurements, accelerometer, and dynamic strain measurement. The maximum dynamic responses from the measured data are compared with those from the finite element method. The experimental model test can be used to obtain to the dynamic responses of the plate-girder bridges.

• Journal of Korean Society of Steel Construction
• /
• v.10 no.2 s.35
• /
• pp.253-261
• /
• 1998

The buckling length of exterior beam-columns of the first floor in moment resisting steel frames with weak beams is uncertain when plastic hinges occur at the ends of weak beams due to seismic loads. The objective of this study is to investigate the buckling strength of concrete-filled tubular beam-columns and to suggest the reduced buckling length of them to apply to the beam-column design code. The exterior beam-columns are modelized with horizontal displacement restraint springs. Their strength and reduced buckling length are evaluated by numerical analysis.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2018.05a
• /
• pp.45-46
• /
• 2018

The fire at the pilotis parking lot shows the fire propagation paths that are propagated to the ceiling materials and insulation materials and propagated through the external walls. In addition, there is a high risk of fire caused by vehicles with high combustion loads spreading throughout the parking lot. In particular, the omission of the ceiling materials at the parking lot in recent fire cases has contributed to the spread of the fire. In this study, the combustion performance of the ceiling materials between the insulation material and the vehicle is considered to prevent fire from spreading. Based on field research, the type of ceiling material used in the piloti structure showed that SMC ceiling materials have the highest percentage. Combustion performance test (KS F ISO 5660-1) was carried out on the SMC ceiling materials and the AL ceiling materials to review the fire safety of the ceiling finish based on the field investigation. The results of the test showed that the SMC ceiling materials has a THR 28.973[MJ/㎡] and peek HRR 273.93 [kW/㎡], while the AL ceiling material has a THR 0.584[MJ/㎡] and peek HRR 15.215[kW/㎡].

• Wind and Structures
• /
• v.8 no.5
• /
• pp.357-372
• /
• 2005

Mean and extreme pressure distributions on a large cantilevered flat roof model are measured in a boundary layer wind tunnel. The largest peak suction values are observed from pressure taps beneath conical "delta-wing type" corner vortices that occur for oblique winds, then the characteristics and causes of the local peak suctions are discussed in detail. Power spectra of fluctuating wind pressures measured from some typical taps located at the roof edges under different wind directions are presented, and coherence functions of fluctuating pressures are also obtained. Based on these results, it is verified that the peak suctions are highly correlated with the conical vortices. Furthermore, according to the characteristics of wind loads on the roof, an aerodynamic solution to minimize the peak suctions by venting the leading edges and the corners of the roof is recommended. The experimental results show that the suggested strategy can effectively control the generation of the conical vortices and make a reduction of 50% in mean pressures and 25% in extreme local pressures at wind sensitive locations on the roof.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.24 no.3
• /
• pp.230-239
• /
• 2012

Ground-coupled heat pump (GCHP) systems utilize the immense renewable storage capacity of the ground as a heat source or sink to provide space heating, cooling, and domestic hot water. The main objective of the present study is to investigate the cooling and heating performance of a small scale GCHP system with horizontal ground heat exchanger (HGHE). In order to evaluate the performance, a water-to-air ground-source heat pump unit connected to a test room with a net floor area of 18.4 m2 and a volume of 64.4 m3 in the Korea Institute of Construction Technology ($37^{\circ}39'N$, $126^{\circ}48'E$) was designed and constructed. This GCHP system mainly consisted of slinky-type HGHE with a total length of 400 m, indoor heat pump, and measuring devices. The peak cooling and heating loads of the test room were 5.07 kW and 4.12 kW, respectively. The experimental results were obtained from March 15, 2011 to August 31, 2011 and the performance coefficients of the system were determined from the measured data. The overall seasonal performance factor (SPF) for cooling was 3.31 while the system delivered heating at a daily average performance coefficients of 2.82.