• Structural Engineering and Mechanics
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• 제76권1호
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• pp.83-99
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• 2020

Shear walls are structural members in buildings that are used extensively in reinforced concrete frame buildings, and almost exclusively in the UK, regardless of whether or not they are actually required. In recent years, the UK construction industry, led by the Concrete Centre, has questioned the need for such structural elements in low to mid-rise reinforced concrete frame buildings. In this context, a typical modern, 5-storey residential building is studied, and its existing shear walls are replaced with columns as used elsewhere in the building. The aim is to investigate the impact of several design variables, including concrete grade, column size, column shape and slab thickness, on the building's structural performance, considering two punching shear limits (V_Ed/V_Rd,c), lateral drift and accelerations, to evaluate its maximum possible height under wind actions without the inclusion of shear walls. To facilitate this study, a numerical model has been developed using the ETABS software. The results demonstrate that the building examined does not require shear walls in the design and has no lateral displacement or acceleration issues. In fact, with further analysis, it is shown that a similar building could be constructed up to 13 and 16 storeys high for 2 and 2.5 punching shear ratios (V_Ed/V_Rd,c), respectively, with adequate serviceability and strength, without the need for shear walls, albeit with thicker columns.

• Advances in Computational Design
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• 제8권1호
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• pp.13-36
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• 2023

The Puebla-Morelos Earthquake (Mw 7.1) occurred in Mexico in 2017 causing 44 buildings to collapse in Mexico City. This work evaluates the non-linear response of a 6-story reinforced concrete (RC) frame prototype model with masonry infill walls on upper floors. The prototype model was designed using provisions prescribed before 1985 and was subjected to seismic excitations recorded during the earthquakes of 1985 and 2017 in different places in Mexico City. The building response was assessed through a damage index (DI) that considers low-cycle fatigue of the steel reinforcement in columns of the first floor, where the steel was modeled including buckling as was observed in cases after the 2017 earthquake. Isocurves were generated with 72 seismic records in Mexico City representing the level of iso-demand on the structure. These isocurves were compared with the location of 16 collapsed (first-floor column failure) building cases consistent with the prototype model. The isocurves for a value greater than 1 demarcate the location where fatigue failure was expected, which is consistent with the location of 2 of the 16 cases studied. However, a slight increase in axial load (5%) or decrease in column cross-section (5%) had a significant detrimental effect on the cumulated damage, increasing the intensity of the isocurves and achieving congruence with 9 of the 16 cases, and having the other 7 cases less than 2 km away. Including column special detailing (tight stirrup spacing and confined concrete) was the variable with the greatest impact to control the cumulated damage, which was consistent with the absence of severe damage in buildings built in the 70s and 80s.

• Earthquakes and Structures
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• 제24권3호
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• pp.217-235
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• 2023

Orthogonal pairs of rollers on concave beds (OPRCB) are a low-cost, low-tech rolling-based isolating system, whose high efficiency has been shown in a previous study. However, seismic performance of OPRCB isolators has only been studied in the two-dimensional (2D) state so far. This is while their performance in the three-dimensional (3D) state differs from that of the 2D state, mainly since the vertical accelerations due to rollers' motion in their beds, simultaneously in two orthogonal horizontal directions, are added up and resulting in bigger vertical inertia forces and higher rolling resistance. In this study, first, Lagrange equations were used to derive the governing equations of motion of the OPRCB-isolated buildings in 3D. Then, some regular shear-type OPRCB-isolated buildings were considered subjected to three-component excitations of far- and near-source earthquakes, and their responses were compared to those of their fixed-base counterparts. Finally, the effects of more realistic modeling and analysis were examined by comparing the responses of isolated buildings in 2D and 3D states. Response histories were obtained by the fourth-order Runge-Kutta-Nystrom method, considering the geometrical nonlinearity of isolators. Results reveal that utilizing the OPRCB isolators effectively reduces the acceleration response, however, depending on the system specifications and earthquake characteristics, the maximum responses of isolated buildings in the 3D state can be up to 40% higher than those in the 2D state.

• 콘크리트학회지
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• 제23권4호
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• pp.33-39
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• 2011

• 콘크리트학회지
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• 제26권1호
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• pp.16-21
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• 2014

• 국제초고층학회논문집
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• 제3권1호
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• pp.65-71
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• 2014

Baku, the capital of Azerbaijan, has seen a boom in construction in recent years. The old Baku city has been rapidly transforming into a new hub of high-rise buildings and lively cultural centers hosting the Euro Vision Song Contest in 2012 and European Games in 2015. A major population shift to Baku from its suburbs and the countryside has resulted in the doubling of Baku's population in the 4 years between 2009 and 2013. As of January 2013, Baku's population reached four million people, 43% of the citizens in Azerbaijan according to The State Statistical Committee of Azerbaijan. With this trend, the city needs more high-rise buildings to accommodate rapidly increasing demands for more housing and business space. Until the Azerbaijan Seismic Building Code was published in 2010 and became effective, many different seismic criteria, in terms of building codes and seismic intensities, were used for all new high-rise projects in Baku. Some designers used the SNIP (Russian) code with seismic level 9 or level 8 with 1 point penalty. Others used the Turkish code with Seismic Zone 1, UBC 97 with Zone 2 through 4, or IBC with Sa = 0.75 g through 1.0 g. The seismic intensity is now clarified with the Azerbaijan Seismic Building Code. However, the Azerbaijan Seismic Building Code is appropriate for low-rise buildings applications but may be inappropriate for high-rise project applications. This is because the code-defined response spectrum yields unrealistically conservative seismic forces for high-rise buildings with long periods, as compared to those determined by other internationally accepted building codes. This paper provides observations and recommendations for code-based seismic load assessment of high-rise buildings in the Baku area.

• 한국지진공학회논문집
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• 제21권4호
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• pp.163-170
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• 2017

The need for eco-friendly building materials such as engineered wood has increased to reduce carbon emissions. Although the range and height of engineered wood buildings are gradually increasing in North America and Europe, engineered wood is mainly used for low-rise residential buildings in Korea. In order to reduce carbon emissions more, therefore, it needs to expand the use of engineered wood by applying it to various buildings with different uses or more stories. With this background, the aim of this study is to investigate the applicability of engineered wood for 9-story office buildings. Since a 9-story building with engineered wood only is not allowed in KBC, an example building has RC ordinary shear walls as the lateral force resisting system while engineered wood is only used for gravity load resisting moment frames. Another example building is also used for comparison where both lateral and gravity load resisting systems are designed by RC. The applicability of engineered wood is investigated by comparing the seismic performance and the amount of carbon emission of both buildings. The result shows that the seismic performance of both buildings was not significantly different while the amount of carbon emission of the engineered wood building was much less then the RC building. Based on this result, engineered wood is sufficiently applicable to 9-story office buildings even though it still needs to pay attention to the shear design of reinforce concrete walls.

• Journal of the Korean Wood Science and Technology
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• 제42권2호
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• pp.89-100
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• 2014

Energy consumption statistics in 2005 from the Korea Energy Management Corporation show that building energy usage was about 24.2% of total domestic energy consumption, and 64% of total building energy usage was consumed by residential buildings. Thus, about 10% of total domestic energy consumption is due to the heating of residential buildings. Building energy can be calculated by the configuration of the building envelope and the rate of infiltration (the volume of the infiltration of outdoor air and the leakage of indoor air), and by doing so, the annual energy usage for heating and cooling. Therefore, air-tightness is an important factor in building energy conservation. This investigate air infiltration and various factors that decrease it in timber frame buildings and suggest ways to improve air-tightness for several structural types. Timber frame buildings can be classified into light frame, post and beam, and log house. Post and beam includes Han-ok (a Korean traditional building). Six light frame buildings, three post and beam buildings, one Korean traditional Han-ok and a log house were selected as specimens. Blower door tests were performed following ASTM E779-03. The light frame buildings showed the highest air-tightness, followed by post and beam structures, and last, log houses.

• Wind and Structures
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• 제14권6호
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• pp.499-515
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• 2011

Low-frequency building vibration is known to induce symptoms of motion sickness in some occupants. This paper examines how the adoption of a theory of motion sickness, in conjunction with a dose-response model might inform the real-world problem of managing and designing standards for tall building motion sway. Building designers require an understanding of human responses to low-dosage motion that is not adequately considered by research into motion sickness. The traditional framework of Sensory Conflict Theory is contrasted with Postural Instability Theory. The most severe responses to motion (i.e., vomiting) are not experienced by occupants of wind-excited buildings. It is predicted that typical response sets to low-dosage motion (sleepiness and fatigue), which has not previously been measured in occupants of tall-buildings, are experienced by building occupants. These low-dose symptoms may either be masked from observation by the activity of occupants or misattributed to the demands of a typical working day. An investigation of the real-world relationship between building motion and the observation of low-dose motion sickness symptoms and a degradation of workplace performance would quantify these effects and reveal whether a greater focus on designing for occupant comfort is needed.

• 한국농촌건축학회논문집
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• 제25권2호
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• pp.9-16
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• 2023

This study attempted to analyze the aspect of seeking a characteristic regeneration of low-rise residential areas through the Urban Regeneration New Deal Project in Seohak-dong Art Village in Jeonju, while the urban regeneration new deal projects are being carried out in various regions, nationwide. Time-series changes in aerial photographs in the study area, age, number of floors, and uses of buildings were examined. The main street structure, lots, and changes in buildings were reviewed, and through this, spatial zones that could extract the unique characteristics of the target area were classified. The characteristics of each area was linked to the proposal of an appropriate regeneration plan through the analysis. This study is meaningful in showing a case of characteristics of low-rise residential areas regeneration plan suitable for the specific region while the number of old low-rise residential areas is increasing.