• Earthquakes and Structures
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• v.19 no.3
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• pp.175-188
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• 2020

The Hengda Group super high-rise building in Jinan City uses the frame-core tube structural system. With a height of 238.3 m, it is above the B-level height limit of 150 m for buildings within 7-magnitude seismic fortification zones. Therefore, it is necessary to apply performance-based seismic design to this super high-rise building. In this study, response spectrum analysis and comparative analysis of the structure are conducted using two software applications. Moreover, elastic time-history analysis, seismic analysis under an intermediate earthquake, and elastic-plastic time-history analysis under rare earthquakes are performed. Based on the analysis results, corresponding strengthening measures are implemented at weaker structural locations, such as corners, wall ends connected to framed girders, and coupling beams connected to framed girders. The failure mode and failure zone of major stress components of the structure under rare earthquakes are analysed. The conclusions to this research demonstrate that weaker locations and important parts of the structure satisfy the requirements for elastic-plastic deformation in the event of rare earthquakes.

• Structural Engineering and Mechanics
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• v.57 no.5
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• pp.861-876
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• 2016

The determination of the critical buckling load of multistory structures is important since this load is used in second order analysis. It is more realistic to determine the critical buckling load of multistory structures using the whole system instead of independent elements. In this study, a method is proposed for designating the system critical buckling load of torsion-free structures of which the load-bearing system consists of frames and shear walls. In the method presented, the multistory structure is modeled in accordance with the continuous system calculation model and the differential equation governing the stability case is solved using the differential transform method (DTM). At the end of the study, an example problem is solved to show the conformity of the presented method with the finite elements method (FEM).

• Steel and Composite Structures
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• v.51 no.5
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• pp.487-498
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• 2024

Steel moment resisting frames (MRFs) typically have inter-story drift concentrations at lower stories during earthquakes as found from previous research. Hinged walls (HWs) can be used as structural strengthening components to force the MRFs deform uniformly along the building height. However, large moment demands are often observed on HWs and make the design of HWs non-economical. This paper proposes a method to reduce the moment demand on HWs using a ductile connection system between the MRFs and the HWs. The ductile connection system is designed with a yield strength and energy dissipation capacity, for the purpose of limiting the seismic forces transferred to the HWs and dissipating seismic energy. Nonlinear time history analyses were performed using 10 far-filed earthquakes at maximum considered earthquake level. The analysis results show that the proposed ductile connection system can reduce: (1) seismic moment demands in the HWs; (2) floor accelerations; (3) the connection force between HWs and MRFs.

• Journal of the Earthquake Engineering Society of Korea
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• v.5 no.5
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• pp.73-83
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• 2001

The mass and stiffness of upper wall-lower frame system(mixed building structures) change sharply at transfer floor due to different structural system in upper and lower part. These mixed building structures generally show the stiffness, weight or geometric vertical irregularities. The purpose of this study is to investigate the response characteristics of these structures by push-over analysis and nonlinear time history analysis. For four types of analysed models, only the variation of upper wall stories was considered. The conclusions of this study are following; (1) In the push-over analysis, yielding hinges in beams and columns of lower frame occurred at the base shear of similar magnitude in all models. But as the number of stories of upper wall increases, yielding hinges at ends of coupling beams were observed in the small magnitude of base shear. (2) In the nonlinear time history analysis, yielding of lower frame occurred at beams with as small ground acceleration as 55gal, and in upper walls yielding was concentrated on coupling beams and shear walls near the transfer floor. (3) As the number of stories of upper walls decreases, the story stiffness of the lower frames decreased relatively and the occurrence of soft stories in the lower frame was observed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.579-585
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• 2017

Development of a facade system that can reduce load factor and costs in high-rise building construction is required. The proposed cable wall system is used as a structural support by the glass-cable and can increase openness on lower elevations and the lobby area. Its use in high-rise buildings can reduce construction costs. Without transferring directly a strong initial tension of the cable to the building frame is connected to the steel member and the reinforced concrete structures, by absorbing the initial tension of the cable, it is possible to control the occurrence of a strong concentrated loads to the structure. Comparison of load-displacement test results from the numerical analysis with the test results showed reasonable agreement, Therefore, the proposed numerical results confirm good prediction of cable behavior for the facade system.

• Journal of Korean Association for Spatial Structures
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• v.19 no.3
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• pp.33-40
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• 2019

A seismic isolation system is one of the most effective control devices used for mitigating the structural responses due to earthquake loads. This system is generally used as a type of base isolation system for low- and mid-rise building structures. If the base isolation technique is applied to high-rise buildings, a lot of problems may be induced such as the movement of isolation bearings during severe wind loads, the stability problem of bearings under large compression forces. Therefore, a mid-story isolation system was proposed for seismic protection of high-rise buildings. Residence-commerce complex buildings in Korea have vertical irregularity because shear wall type and frame type structures are vertically connected. This problem can be also solved by the mid-story isolation system. An effective analytical method using super elements and substructures was proposed in this study. This method was used to investigate control performance of mid-story isolation system for residence-commerce complex buildings subjected to seismic loads. Based on numerical analyses, it was shown that the mid-story isolation system can effectively reduce seismic responses of residence-commerce complex tall buildings.

• Structural Engineering and Mechanics
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• v.59 no.6
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• pp.1121-1137
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• 2016

A large number of structure in the world were build with poor seismic details, with or without any lateral load resisting system like concentrically braced frames and steel plate shear walls. These structures can reveal deteriorating hysteretic behaviors with stiffness and strength degradation. Therefore, seismic retrofitting of such structures for drift control has vital importance. In this study a retrofit methodology has been developed, which involves diagonal bracing of steel frames with different cable arrangements. In the experimental and numerical program 5 different lateral load resisting system were tested and results compared with each other. The results indicated that multi-cable arrangements suggested in this study showed stable ductile behavior without any sudden decrease in strength. Due to the usage of more than one diagonal cable, fracture of any cable did not significantly affect the overall strength and deformation capacity of the system. In cable braced systems damages concentrated in the boundary zones of the cables and beams. That is why boundary zone must have enough stiffness and strength to resist tension field action of cables.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.17 no.2
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• pp.215-222
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• 2004

Drift design methods using resizing techniques have been presented as a practical drift control methods of high-rise buildings. Most drift design methods using the resizing techniques have adopted the cross-sectional area as the design variables for all structural members in a structure. However, the cross-sectional area is not always governing sectional property for the structural members, but the governing sectional property of each member is dependent on the characteristics of member forces. In this paper, a drift design method using the sectional property related to the governing displacement participation factor as the design variable of each member is presented and applied to the drift design of 20-story steel frame-shear wall system. It can be noted from example test that drift design method considering member characteristics shows similar or somewhat better results in the view point of structural weights and the accuracy of displacement estimation.

• Journal of Korean Society of Steel Construction
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• v.18 no.4
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• pp.457-468
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• 2006

An experimental study was performed to investigate the maximum energy dissipation and the ductility capacity of shear-dominated steel plate walls with thin web plates. Three specimens of three-story plate walls with thin web plates were tested. The parameters for the test specimens were the aspect ratio of the web plate and the shear strength of the column. A concentrically braced frame and a moment-resisting frme were a also tested for comparison. The steel plate walls exhibited much better ductility and energy dissipation capacity than the concentrically braced frame and the moment-resisting frame. The results showed that unlike other structural systems, the sh as well as strength, and can therefore be used as an effective earthquake-resisting system. A method of predicting the energy dissipation capacity of a steel plate wall was proposed.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.1
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• pp.59-67
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• 2013

Complex-shaped tall building causes many structural challenges due to its structural characteristics regarding inclined members and complexed shape. This paper is aimed at development of design process using computational-platform which is effective design tool for responding frequent design changes, particularly as to overseas projects. StrAuto, a parametric structural modeling and optimizing system, provides the optimized alternatives according to design intent and realize a swift process converting a series of structural information necessary to nonlinear analytical models. The application of the process was to a 45-story hotel building in Ulanbator, Mongolia adopting shear wall and special moment frame with outrigger systems. To investigate the safety of lateral force resisting system against maximum considered earthquake(MCE), nonlinear response history analysis was conducted using StrAuto.