• Wind and Structures
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• 제21권5호
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• pp.523-536
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• 2015

To study the vibration frequency of super high-rise buildings in the process of vortex induced vibration (VIV), wind tunnel tests of multi-degree-of-freedom (MDOF) aero-elastic models were carried out to measure the vibration frequency of the system directly. The effects of structural damping, wind field category, mass density, reduced wind velocity ($V_r$), as well as VIV displacement on the VIV frequency were investigated systematically. It was found that the frequency drift phenomenon cannot be ignored when the building is very high and flexible. When $V_r$ is less than 8, the drift magnitude of the frequency is typically positive. When $V_r$ is close to the critical wind velocity of resonance, the frequency drift magnitude becomes negative and reaches a minimum at the critical wind velocity. When $V_r$ is larger than12, the frequency drift magnitude almost maintains a stable value that is slightly smaller than the fundamental frequency of the aero-elastic model. Furthermore, the vibration frequency does not lock in the vortex shedding frequency completely, and it can even be significantly modified by the vortex shedding frequency when the reduced wind velocity is close to 10.5.

• 한국강구조학회 논문집
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• 제26권4호
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• pp.299-309
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• 2014

HSA800은 건축구조용 고성능 강재로서 KS규격에 항복강도 650MPa-770MPa, 인장강도 800MPa-950MPa를 가지며 항복비(항복강도/인장강도) 또한 0.85이하로 제한되어있으며 TMCP 기법으로 제조되어 뛰어난 용접성을 나타내는 특징이 있다. 본 연구에서는 국내 최초의 초고층 빌딩인 롯데월드타워의 메가 구조부재를 대상으로 고강도 강재 적용시 구조물 안전성의 변동사항 및 시공성 개선 등을 검토하여 경제적 설계를 위한 대안을 제시하는 것을 목적으로 한다. 대상 부재로는 아웃리거 코어월 매립부 상/하현재, 벨트트러스, 외곽 철골기둥이 선정되었다. 원설계 단면을 등가 도강도 강재 단면으로 환산하여 두께를 결정한 후 중력저항모델, 횡력저항모델, 연쇄붕괴 모델을 구조해 석시뮬레이션을 통하여 성능을 비교 평가하였다. 그 결과 횡강성에 영향을 주지 않는 부재는 고강도 강재 적용이 가능하며 원설계 대비 약 1100톤의 물량 절감 효과가 있었다. 따라서, 고강도 강재를 사용하면 부재 두께를 줄일 수 있으므로 부재 제작성 및 시공성이 향상될 수 있을 것으로 기대된다.

• 한국화재소방학회논문지
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• 제26권5호
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• pp.92-98
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• 2012

최근 개정된 초고층건물 특별법에서는 피난안전구역을 최소 30개층 마다 설정함과 동시에 계단실을 수직구획 하도록 규정하고 있다. 이에 본 연구에서는 중앙코아 방식의 80층 초고층건물 계단실 수직구획이 연돌효과 및 계단실 급기가압 성능에 미치는 영향을 시뮬레이션 해석을 통해 분석하였다. 해석결과, 계단실 수직구획이 없는 경우 연돌효과로 인해 최대 차압 250 Pa 이상이 발생하였으며, 계단실만 수직구획한 경우에는 10 Pa 정도만 감소하였으나 계단실과 승강기의 승강로를 동시에 수직구획한 경우 최대차압이 약 125 Pa로 낮아져 연돌효과가 약 50 % 감소하였다. 또한, 계단실을 급기가압 할 경우 계단실온도가 실내온도와 외기온도 차이의 약 1/2일 때가 소요급기풍량 측면에서 가장 효율적인 것으로 예측되었다.

• Structural Engineering and Mechanics
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• 제87권5호
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• pp.451-460
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• 2023

Recently, the use of smartphones for structural health monitoring in civil engineering has drawn increasing attention due to their rapid development and popularization. In this study, the structural responses and dynamic characteristics of a 421-m-tall skyscraper during the landfall of Typhoon Muifa are monitored using an iPhone 13. The measured building acceleration responses are first corrected by the resampling technique since the sampling rate of smartphone-based measurement is unstable. Then, based on the corrected building acceleration, the wind-induced responses (i.e., along-wind and across-wind responses) are investigated and the serviceability performance of the skyscraper is assessed. Next, the amplitude-dependency and time-varying structural dynamic characteristics of the monitored supertall building during Typhoon Muifa are investigated by employing the random decrement technique and Bayesian spectral density approach. Moreover, the estimated results during Muifa are further compared with those of previous studies on the monitored building to discuss its long-term time-varying structural dynamic characteristics. The paper aims to demonstrate the applicability and effectiveness of smartphones for structural health monitoring of high-rise buildings.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2008년도 춘계학술논문발표회 논문집
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• pp.29-32
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• 2008

Recently with the increasing economics, many hish-rise and complicated building with new architecture features are constructed in Korea. These tall and big building have many difficulties of fire safety concerns, especially evacuation plan. so, If a fire breaks out in big shopping center in the super tall building, how should the occupants evacuate? In the side of this evacuate problem of big shopping center, It is the aim of this study to compare and analyze the difference between America and Korea. Considering the Physical Characteristics and Occupant Density.

• Wind and Structures
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• 제20권4호
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• pp.527-548
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• 2015

Aeroelastic wind tunnel experiments were conducted for conventional and tapered super-tall building models to investigate the effect of taper on fundamental aeroelastic behaviors in various incident flows. Three incident flows were simulated: a turbulent boundary-layer flow representing urban area; a low-turbulent flow; and a grid-generated flow. Results were summarized focusing on the effect of taper and the effect of incident flows. The suppression of responses by introducing taper was profound in the low-turbulence flow and boundary-layer flow, but in the grid-generated flow, the response becomes larger than that of the square model when the wind is applied normal to the surface. The effects of taper and incident flows were clearly shown on the normalized responses, power spectra, stability diagrams and probability functions.

• 콘크리트학회지
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• 제16권3호
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• pp.16-26
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• 2004

• 국제초고층학회논문집
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• 제6권1호
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• pp.49-72
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• 2017

The Guangzhou International Finance Centre (IFC) is a landmark building that symbolizes the emerging international strength of Guangzhou, China's third largest city. It is also one of the dual iconic towers along the main axis of Guangzhou Zhujiang New Town. Arup adopted a total engineering approach in embracing sustainability and aiming at high efficiency solutions based on performance-based design principles covering structures, building services, fire engineering, vertical transportation, and façade performance to constitute an efficient and cost-effective overall building design. Through dynamic integration of architectural and engineering principles, Guangzhou IFC represents a pioneering supertall building in China. It adopts a diagrid exoskeleton structural form that is clearly expressed through the building's façade and gives the building its distinctive character. The aerodynamic shape of the building not only presents the aesthetic quality of elegant simplicity, but also reduces the effects of wind, thereby reducing the size and weight of the structure. State-of-the-art advanced engineering methods, such as optimization techniques and nonlinear finite element modelling, were applied in parallel with large-scale experimental programs to achieve an efficient and high-performance design taking into account the constructability and cost-effectiveness for a project of this scale.

• 국제초고층학회논문집
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• 제6권1호
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• pp.83-89
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• 2017

Due to the time-dependent properties of materials, structures, and loads, accurate time-dependent effects analysis and precise construction controls are very significant for rational analysis and design and saving project cost. Elevation control is an important part of the time-dependent construction control in supertall structures. Since supertall structures have numerous floors, heavy loads, long construction times, demanding processes, and are typically located in the soft coastal soil areas, both the time-dependent features of superstructure and settlement are very obvious. By using the time-dependent coupling effect analysis method, this paper compares Shanghai Tower's vertical deformation calculation and elevation control scheme, considering foundation differential settlement. The results show that the foundation differential settlement cannot be ignored in vertical deformation calculations and elevation control for supertall structures. The impact of foundation differential settlement for elevation compensation and pre-adjustment length can be divided into direct and indirect effects. Meanwhile, in the engineering practice of elevation control for supertall structures, it is recommended to adopt the multi-level elevation control method with relative elevation control and design elevation control, without considering the overall settlement in the construction process.

• 한국건설관리학회논문집
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• 제13권5호
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• pp.135-143
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• 2012

초고층 건축물은 일반적 건축물에 비해, 구조, 환경적 분야 뿐 아니라 시공 분야에서도 골조공사와 마감공사의 시공방법, 재료, 공사관리 등에서 차이점이 있다. 특히 초고층 건축물 시공에서 요구되는 다양한 관리기법 중 양중계획 및 관리는 핵심적인 분야이며, 건설공사에 필요한 인원 및 자재와 같은 자원을 리프트카와 같은 양중기계장비를 이용하여 효율적으로 수직이동하여야 한다. 그러나 리프트카의 경우 초기 수립된 계획과 실제 운영에 차이가 발생하는 경우가 많고 이러한 비효율성으로 인해 문제가 발생하는 경우가 많다. 본 연구에서는 양중작업에 사용되는 리프트카를 대상으로 건축마감공사의 자원물량에 근거한 양중부하 산정 방법 및 예측 모델을 제시하고자 한다. 그 결과 리프트카 운행시간 및 사이클타임을 계산하여 총 양중장비 가동시간 및 양중가능 물량을 산출할 수 있을 것이다. 이를 양중장비조합을 위한 의사결정 지원 모델 구축을 위한 연구로 발전시켜 나갈 것이다.