• Wind and Structures
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• 제23권5호
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• pp.449-464
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• 2016

Catastrophe models appraise the natural risk of the built-infrastructure simulating the interaction of its exposure and vulnerability with a hazard. Because of unique configurations and reduced number, mid/high-rise buildings present singular challenges to the assessment of their damage vulnerability. This paper presents a novel approach to estimate the vulnerability of mid/high-rise buildings (MHB) which is used in the Florida Public Hurricane Loss Model, a catastrophe model developed for the state of Florida. The MHB vulnerability approach considers the wind pressure hazard exerted over the building's height as well as accompanying rain. The approach assesses separately the damages caused by wind, debris impact, and water intrusion on building models discretized into typical apartment units. Hurricane-induced water intrusion is predicted combining the estimates of impinging rain with breach and pre-existing building defect size estimates. Damage is aggregated apartment-by-apartment and story-by-story, and accounts for vertical water propagation. The approach enables the vulnerability modeling of regular and complex building geometries in the Florida exposure and elsewhere.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2009년도 추계학술발표대회 논문집
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• pp.33-36
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• 2009

Korea is the 3rd highest country in population density of the world,furthermore, 1/5 of Korean lives in Seoul with only 0.0% tiny area size. It explains the high-rise apartment has diffused so fast. Regardless of its height, almost all apartments have been planned in a very uniform way, ignoring the possibilities of vertical community and commercial culture. Since considerable number of residents have within building, ways to improve the community and commercial culture need to be explored. One major way to do is providing community space where residents are expected to use in a natural way. The purpose of this research is to identify preferred location of community space in each apartment building. Web guesting survey was used as main methodology. 83 data were collected during mid October, 2009. As results, lobby at the first floor was most favorably selected by super high-rise apartment residents due to convenience, accessibility.

• Wind and Structures
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• 제24권2호
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• pp.145-169
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• 2017

The auxiliary structures of a high-rise building, such as balconies, ribs, and grids, are usually much smaller than the whole building; therefore, it is difficult to simulate them on a scaled model during wind tunnel tests, and they are often ignored. However, they may have notable effects on the local or overall wind loads of the building. In the present study, a series of wind pressure wind tunnel tests and high-frequency force balance (HFFB) wind tunnel tests were conducted on rigid models of an actual super high-rise building with vertical ribs protruding from its facades. The effects of the depth and spacing of vertical ribs on the mean values, fluctuating values and the most unfavorable values of the local wind pressure coefficients were investigated by analyzing the distribution of wind pressure coefficients on the facades and the variations of the wind pressure coefficients at the cross section at 2/3 of the building height versus wind direction angle. In addition, the effects of the depth and spacing of vertical ribs on the mean values, fluctuating values and power spectra of the overall aerodynamic force coefficients were studied by analyzing the aerodynamic base moment coefficients. The results show that vertical ribs significantly decrease the most unfavorable suction coefficients in the corner recession regions and edge regions of facades and increase the mean and fluctuating along-wind overall aerodynamic forces.

• Computers and Concrete
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• 제8권3호
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• pp.311-325
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• 2011

Nowadays, many engineers believe that hybrid structures with reinforced concrete central core walls and perimeter steel frames offer an economical method to develop the strength and stiffness required for seismic design. As a result, a variety of such structures have recently been applied in actual construction. However, the performance-based seismic design of such structures has not been investigated systematically. In the performance-based seismic design, quantifying the seismic damage of complete structures by damage indices is one of the fundamental issues. Four damage states and the final softening index at each state for high-rise hybrid structures are suggested firstly in this paper. Based on nonlinear dynamic analysis, the relation of the maximum inter-story drift, the main structural characteristics, and the final softening index is obtained. At the same time, the relation between the maximum inter-story drift and the maximum roof displacement over the height is also acquired. A double-variable index accounting for maximum deformation and cumulative energy is put forward based on the pushover analysis. Finally, a case study is conducted on a high-rise hybrid structure model tested on shaking table before to verify the suggested quantities of damage indices.

• 국제초고층학회논문집
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• 제3권3호
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• pp.167-171
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• 2014

TORANOMON HILLS is the main building of a large-scale re-development project located in the center of Tokyo. This high-rise building has a height of 247 m and 52 floors above ground, 5 floors below ground, and $62m{\times}80m$ in plan. It is used as hotel, residential facilities, offices, shops and conference facilities. The super structure is mainly a rigid steel frame with response-control devices, using concrete-filled steel tube columns. The underground section is a mixed structure composed of steel, steel-reinforced concrete and reinforced concrete framings. The piled-raft foundation type is used. The remarkable feature of this high-rise building is that the motorway runs through the basements of the building, which makes it stand just above the motorway. This condition is an important factor of the building design. The plan shape is designed to fit along the curve of the motorway. Special columns at the corners are required to avoid placing columns in the motorway. This special column is a single inclined column in the lower floors that branches into two columns in the mid-floors to suit the column location in the upper floors. The cast steel joint is used for the branching point of each special column to securely transfer the stress.

• KIEAE Journal
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• 제16권3호
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• pp.95-101
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• 2016

Purpose: Recently, high-rise buildings are popular in korea due to high rate of land usage and cost performance in urban area. However, high-rise building causes several problems such as safety issues, cooling/heating load, stack effect, disaster prevention etc. The stack effect is one of the representative problems. Even though there are many researches on stack effect, there are few studies on design guideline considering local condition. Method: This study focuses on the change of pressure distribution according to the design factors which affects the airflow in high-rise residential buildings by simulation analysis. In this study, city, building floor, stairwell door leakage area, elevator door leakage area and changes of layout were considered ad the design factor. Result: The simulation results indicate that building height and ambient air temperature are significant design factor for stack effect.

• 한국화재소방학회논문지
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• 제25권5호
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• pp.14-20
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• 2011

건축물이 고층화되면서 피난을 위한 주요 시설인 피난계단에서는 수직적 구조로 인해 연돌효과의 영향이 크게 발생하고 있다. 동절기에 연돌효과로 인한 계단실의 압력상승으로 피난문을 열고 대피하는데 어려움이 있고, 피난계단의 연기안전을 위한 급기가압 제연시스템의 운전성능에 교란이 발생되기 때문에 피난계단에서의 연돌효과를 저감시켜야 더욱 안전한 대피환경을 제공할 수 있다. 본 연구에서는 고층 건물에서의 현장실험을 통해 피난계단에서의 연돌효과를 저감시킬 수 있는 방안을 도출하였고, 네트워크 모델을 사용한 수치해석을 수행하여 정량적이고 상세한 설계방안을 제시하였다. 현장실험 결과 피난계단의 저층부에서 피난계단으로 공기가 급기되고 고층부에서 피난계단의 외부로 공기가 배기되도록 공기의 흐름을 생성시켜 준다면 고층 건물의 피난계단에서의 연돌효과가 저감될 것으로 예측된다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1220-1225
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• 2009

A manipulator is operated for the motion of mechanical hands or arms. When a cup including liquid inside is shifted by a manipulator, it is important to know how a free surface of the liquid moves. In this study, non dimensional parameters have been found that affect the rise of the free surface in a cup moving with constant acceleration. The non-dimensional parameters are the dimensionless time, the ratio of inertia effect to viscous effect (the Reynolds number), aspect ratio of the liquid inside the cup and the acceleration ratio (the Froude number). Through this study, the height of the free surface rise in a cup has been predicted and the detailed velocities in the liquid have been examined. Generally, the maximum rise of the free surface is dependent on the Reynolds number and Froude number strongly, but on the aspect ratio weakly. However, the influence of the aspect ratio on the maximum rise of the free surface is not negligible in the range of 10 < Re < 100.

• Wind and Structures
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• 제11권6호
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• pp.497-512
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• 2008

In this paper, optimum methods of wind-induced vibration control of high-rise buildings are mainly studied. Two optimum methods, genetic algorithms (GA) method and Rayleigh damping method, are firstly employed and proposed to perform optimum study on wind-induced vibration control, six target functions are presented in GA method based on spectrum analysis. Structural optimum analysis programs are developed based on Matlab software to calculate wind-induced structural responses. A high-rise steel building with 20-storey is adopted and 22 kinds of control plans are employed to perform comparison analysis to validate the feasibility and validity of the optimum methods considered. The results show that the distributions of damping coefficients along structural height for mass proportional damping (MPD) systems and stiffness proportional damping (SPD) systems are entirely opposite. Damping systems of MPD and GAMPD (genetic algorithms and mass proportional damping) have the best performance of reducing structural wind-induced vibration response and are superior to other damping systems. Standard deviations of structural responses are influenced greatly by different target functions and the influence is increasing slightly when higher modes are considered, as shown fully in section 5. Therefore, the influence of higher modes should be considered when strict requirement of wind-induced vibration comfort is needed for some special structures.

• 설비공학논문집
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• 제16권9호
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• pp.796-803
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• 2004

The stack effect of a new type condenser installed in a high-rise apartment building was studied numerically A sirocco fan is introduced to the new type condenser instead of an axial flow In. The new type condenser intakes the cold air through the lower inlet and exhausts the hot air through the upper outlet. The effects of the building height and frontal wind on the performance of an air-conditioner were analyzed. The performance of an air-conditioner was evaluated by using COP (coefficient of performance) and CGPI (condenser group performance indicator). the hot air was exhausted by the new type condenser at an angle of 50$^{\circ}$ from the outer wall of the building. If there was no draft, the new type condenser installed in the high-rise apartment building had a good performance and its performance on each floor is not influenced by the stack effect. It is shown that the efficiency of the air-conditioner installed in several floors below the top floor decreased when the frontal wind velocity was greater than 8 m/s.