• Journal of the Korea institute for structural maintenance and inspection
• /
• v.24 no.1
• /
• pp.116-124
• /
• 2020

In order to analyze the lateral-load resisting capability according to the core locations, three-dimensional structural analyses were performed for 20-story buildings with symmetric plan. Four analytical models for a center core, a single-axial eccentric core, and a double-axial eccentric core were constructed, and eigenvalue analyses, wind-load analyses, and earthquake-load analyses were performed. Torsion did not occur in the central core building, but the bending and torsion occurred in combination with the arrangement of the eccentric core, and the lateral-load resisting capability was degraded. The change in the wind load according to the eccentric core was small, but the maximum lateral displacement was found to increase greatly by the eccentric arrangement of the core. In addition, in case of the eccentric core, the seismic load was slightly reduced compared to the center core due to the decrease in the lateral stiffness, but it was found that the maximum story drift ratio increased significantly due to the torsional effect. Based on these results, the structural behavior according to the position of the core can be clearified and used as a guideline for core locations in the planning and design stage.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.10
• /
• pp.490-498
• /
• 2020

In this study, the seismic performance of low-rise piloti buildings with eccentric core (shear wall) positions was analyzed and reviewed. A prototype was selected among constructed low-rise piloti buildings with eccentric cores designed based on KBC2005. The seismic performance of the building showed plastic behavior in the X-direction and elastic behavior in the Y-direction. The inter-story drift is larger than that of a concentric core case and has the maximum allowed drift ratio. The displacement ratio of the first story is much larger than that of upper stories, and the frame structure in the first story is vulnerable to lateral force. Therefore, low-rise piloti buildings with eccentric cores need to have less lateral displacement, as well as reinforcement of the lateral resistance capacity in seismic design and seismic retrofit.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.26 no.1
• /
• pp.19-28
• /
• 2013

In a shear wall-frame structural system, the structural response is determined by the interaction between the shear wall in bending mode and the frame in shear mode. In order to effectively consider these characteristics of a shear wall-frame structure, the simplified numerical model using the T-shape rigid body was suggested in the previous study. Based on the previously proposed model, an efficient numerical model for a wall-frame structure with an eccentric core has been proposed in this study. To this end, the previously proposed 2D model is extended to the 3D model and it is enhanced by considering torsion effects. As a result, the enhanced model can be applied to the analysis of a wall-frame structure with an eccentric core as well as a centric core.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.35 no.1
• /
• pp.29-34
• /
• 2022

In this paper, the floor acceleration for the seismic design of non-structural elements was evaluated using the core shape as a planar variable. Linear time history analysis using 20 models with 5 different planes and 4 different floors on each plane depending on the change in the shape (position and specific gravity) of the core in the square biaxially symmetric plane was performed. The analysis confirmed that the torsional amplification of the floor acceleration was up to 1.7 times in the plane subjected to eccentricity depending on the position of the core, and the effect of torsion was the greatest in the middle floor of the structure. In a plane where only the specific gravity of the core was changed without eccentricity, when the period was less than 0.4694 s, the maximum floor acceleration decreased in the lower floors and increased in the upper floors as the period increased. Conversely, when the period was 0.4694 s or more, it was confirmed that the floor acceleration increased in the lower part and decreased in the upper part as the period increased.

• Land and Housing Review
• /
• v.13 no.3
• /
• pp.83-102
• /
• 2022

After the earthquake in South Korea (Gyeongju and Pohang), interest in securing the seismic performance of piloti buildings was increasing. In this paper, a study was conducted to propose a seismic retrofit method for piloti building of LH. The proposed seismic retrofit method considers the priority of seismic retrofit and the type of core. To verify the effectiveness of the proposed seismic retrofit method, computational analysis was performed according to the type of core. As a result, it was confirmed that the seismic performance was improved when the proposed seismic retrofit method was used.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2009.04a
• /
• pp.561-566
• /
• 2009

The outrigger system with a core is widely used for lateral load resisting system of tall building. Recently, structural systems in tall building are adopted to eccentric core and offset outrigger or one-armed outrigger system by trends in planning buildings of irregular type. Therefore, the performance of outrigger system with eccentric core in tall building is evaluated by 50-stories examples which are analyzed for variables such as layout of core and outrigger, arm length of outrigger and depth of outrigger and belt wall.

• Tunnel and Underground Space
• /
• v.19 no.6
• /
• pp.473-478
• /
• 2009

The accuracy of point load apparatus is depend on point to point coaxial fitting. Also, the estimation of applied point load using the pressure gauge frequently lead to erroneous results. An improved point load apparatus has been developed in this study by mounting linear bearing on polished support rod, and eccentric error of point to point axis has been sustained less than 0.1 mm even under series of extreme work load conditions. Two digital displacement gauges are attached to measure the distance from point to point with sample specimen. A load cell mounted at the end of upper conical platen measure the applied net load on sample instead of preassure gauge. Total of 107 point load tests has been achieved to assure the quality and performance of developed apparatus. This exercise turned out to be successful.

• Journal of Korean Society of Steel Construction
• /
• v.16 no.5 s.72
• /
• pp.529-541
• /
• 2004

Concrete filled steel tube structures were recently used in constructing high-rise buildings due to their effectiveness. Studies on concrete filled steel tubes have been focused on the experiments of uni-axial compression and bending and eccentric compression. There were also a few studies that investigated CFT member behavior under combined compression and torsion. The behavior of a circular CFT column under combined torsion and compression was theoretically investigated, considering the confinement of steel tubes on the concrete, the softening of the concrete, and the spiral effect, which were the dominant factors that influenced compression and torsion strength. The biaxial stress effects due to diagonal cracking were also taken into account. By applying those factors to compatibility and equilibrium conditions, the basic equation was derived, and the equation could be used to incorporate the torsional behavior of the entire loading history of the CFT member.