• Korean Journal of Construction Engineering and Management
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• v.6 no.1 s.23
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• pp.212-219
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• 2005

Time management is important in construction management Especially, in the high-rise apartment housing projects, it is very important to expedite the construction progress in order to meet the planned schedule. The objective of this paper is to propose the baseline for the progress rate using work volume and man $\cdot$ hours performed at work activity level. The work volume far each activity is transformed to the weighted value compared to total work volume for the floor Therefore, a progress rate for an activity is calculated by multiplying a weighted value and work volume. A progress rate for a floor and a building can calculated in this manner, respectively.

• Journal of the Earthquake Engineering Society of Korea
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• v.28 no.1
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• pp.47-57
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• 2024

Recently, in newly constructed apartment buildings, the exterior wall structures have been characterized by thinness, having various openings, and a significantly low reinforcement ratio. In this study, a nonlinear finite element analysis was performed to investigate the crack damage characteristics of the exterior wall structure. The limited analysis models for a 10-story exterior wall were constructed based on the prototype apartment building, and nonlinear static analysis (push-over analysis) was performed. Based on the finite element (FE) analysis model, the parametric study was conducted to investigate the effects of various design parameters on the strength and crack width of the exterior walls. As the parameters, the vertical reinforcement ratio and horizontal reinforcement ratio of the wall, as well as the uniformly distributed longitudinal reinforcement ratio and shear reinforcement ratio of the connection beam, were addressed. The analysis results showed that the strength and deformation capacity of the prototype exterior walls were limited by the failure of the connection beam prior to the flexural yielding of the walls. Thus, the increase of wall reinforcement limitedly affected the failure modes, peak strengths, and crack damages. On the other hand, when the reinforcement ratio of the connection beams was increased, the peak strength was increased due to the increase in the load-carrying capacity of the connection beams. Further, the crack damage index decreased as the reinforcement ratio of the connection beam increased. In particular, it was more effective to increase the uniformly distributed longitudinal reinforcement ratio in the connection beams to decrease the crack damage of the coupling beams, regardless of the type of the prototype exterior walls.

• International Journal of Highway Engineering
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• v.18 no.5
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• pp.49-56
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• 2016

PURPOSES : In this study, noise reduction effect of a two-layer porous asphalt pavement was investigated through site measurement and computer simulation. METHODS : To examine noise reduction effect, a 3 km long quiet pavement was installed by removing previous normal pavement, which had a rather low porosity. The studied site was a high-rise apartment building surrounded by the quiet pavement and Seoul ring road with heavy traffic volume, indicating relatively high background noise. RESULTS : The measurement result before and after installing the quiet pavement showed a noise reduction effect of 4.3 dB(A) at a distance of 7.5 m from the road. After validating the accuracy of simulation using SoundPLAN, the reduction in SPL(sound pressure level) at the facades by the quiet pavement was predicted by considering five different road conditions generating traffic noise from each road or in the combination of the quiet pavement and Seoul ring road. In the case of no noise from Seoul ring road, noise reduction at the facades was 4.2 dB(A) on average for 702 housing units. With background noise from Seoul ring road, however, the average SPL decreased to 2.0 dB(A). Regarding subjective response of noise, the number of housing units with a noise reduction of over 3 dB(A) was 229 out of 706 units (approximately 32%). For 77 housing units, the noise reduction was between 1~3 dB(A), while it was less than 1 dB(A) for 400 housing units. CONCLUSIONS : The overall result indicates that the quiet pavement is useful to reduce noise evenly at low and high floors compared to noise barriers, especially in the urban situation where background noise is low.

• Journal of the Korean Solar Energy Society
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• v.32 no.3
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• pp.1-10
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• 2012

The purpose of this study was to promote the utilization of wind velocity of kitchen and bathroom exhaust ducts for wind power generation in high-rise apartments. The research content can be summarized as follows: 1) Nine high-rise apartments were examined for the installation of kitchen and bathroom exhaust ducts located in the pipe shaft (PS) section. After selecting simulation candidates, a simulation was performed with the STAR-CCM+ Ver 5.06 program. 2) Of nine high-rise apartments, seven had kitchen and bathroom exhaust ducts, whose cross section was in the range of $0.16m^2{\sim}0.4m^2$. The area ratio between the exhaust ducts and PS section (cross section of exhaust duct/area of PS section ${\times}$ 100) was on average 3.2%. 3) The simulation results were analyzed. As a result, the smaller cross section kitchen and bathroom exhaust ducts had, the more advantages there were for increasing exhaust wind velocity. If an out air inlet duct is installed to the old kitchen and bathroom exhaust ducts, it will increase exhaust wind velocity by 3.01~3.98m/s and contribute to the proper wind velocity level (3.0m/s). 4) When the simultaneous usage rate between the kitchen and bathroom exhaust fan increased from 20% to 60%, exhaust wind velocity increased. The "entire house holds" condition for exhaust fan operation provided more even exhaust wind velocity than the "some house holds" condition. 5) Exhaust wind velocity increased in the order of amplified (T-3), induced (T-2) and vertical (T-1) top of kitchen and bathroom exhaust ducts. Of them, the amplified type (T-3) was under the least influence of external wind velocity and thus the most proper for kitchen and bathroom exhaust duct tops.

• Korean Journal of Remote Sensing
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• v.34 no.5
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• pp.749-762
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• 2018

In this study, the changes of the sunshine environment due to the construction of buildings were analyzed by season. Using a geographic information system (GIS) data, the topography and the buildings were constructed around Pukyong National University (PKNU) in Busan. The numerical model was performed for a week in each season, before and after the construction of buildings. Even before the construction of the high-rise building complex, the area of sunshine block is wide due to the apartment complex located in the southeast of the PKNU campus and the mountain in the south. After the construction, the sunshine-blocked area became wider after the sunrise and before the sunset. The area of sunshine block after 1 hour at sunrise increased by 1.60%, 1.50%, 1.58% and 1.36% in the vernal equinox, summer solstice, autumnal equinox and winter solstice, respectively. The building complex in the east (south) of the PKNU campus made shadow in more than 1,000 m (750 m) toward the west (east) just before the sunrise (sunset). Especially, the sunshine duration in PKNU campus decreased by 46.61%, 22.75%, 58.56%, and 11.31% in the vernal equinox, summer solstice, autumnal equinox and winter solstice, respectively. The analysis of the sunshine duration for a dormitory building showed that the construction of the building complex in the south of the PKNU campus reduced the sunshine area of the western (southern) wall of the dormitory by 30.91% (49.45%) for a winter week.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.2 s.109
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• pp.111-121
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• 2005

The Seoul Housing Corporation pronounced an alternative design competition and a bidding for Eunpyeong New Town in December of 2004. At first many construction companies were interested in the first New Town Project. But at last a few companies had proposed the alternative design and construction cost. This project needed a conjunction of design ideas and technology know-hows. And the client wanted the brand power of construction company. Ultimately the Corporation hoped that the first New Town Project will end up with high quality successfully. This competition had started with the original construction drawings. Then it needed some alternative ideas and the lowest cost. There were two drawings of non changeable part and changeable part. Non changeable parts are structure like housing unit plan, underground parking lots. Changeable parts are outdoor layout, interior design and building facade. So we tried all ideas of landscape technology and design principles within limited guidelines. The author applied new technology like tilted rooftop greening and sustained container greening on high-rise apartment house. This green technology will be the first trial in Seoul and in the world as well. Daewoo Corporation have accumulated greening technology through the researches by national funding since 2002. Through this New Town Project the green technology will go forward step by step.

• Korean Journal of Construction Engineering and Management
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• v.22 no.1
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• pp.55-62
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• 2021

The productivity of rebar-work and form-work was analyzed with data collected from an actual high-rise construction project, and the actual utilization rates of three tower cranes were also investigated. It was found that the average productivity of the form-work increased from 12.00~8.71(㎡/man·day) in the underground and above-ground/lower-floor to 11.94~20.73(㎡/man·day) in the standard floor. Comparing the productivity of core area to outer, the former was found to be about 11% higher. Moreover, the rebar-work productivity of the outer area(1.12 ton/man·day) was approximately 9.6% higher than that of the core area for the standard floor. The average utilization rates of three TC were surveyed to be about 63.49%, and it was revealed that rainy weather(6.1%), strong winds(6.1%), holidays(17.8%), TC lifting work(5.8%), and other failures and repairs(0.07%) were the causes of non-operation. These research results are expected to be beneficial data in planning and managing the process of high-rise RC construction works in the future.

• Explosives and Blasting
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• v.22 no.3
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• pp.35-41
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• 2004

Many buildings have been bolt in Korea. Because blasting operations and more efficient to make excavate rock than other methods, it's more extensively used for new construction, enlargement of buildings, subway work, etc. However, blasting vibrations and sound often create pollution. A study, 'The place of gathering earth and sand to construct a building site in Yangsan', has been done in Gyo-dong, in Yangsan. There are two high-rise apartment and buildings, beside a construction site. The blasting vibrations and sound were monitored on the 1st, 4th floors in building(4th floor), and the results of the analysis are as follows: The blasting vibrations decreased being transmited from 1st floor to 4th floor.

• Korean Journal of Remote Sensing
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• v.28 no.2
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• pp.203-214
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• 2012

The physical environment of urban areas covered mostly by concrete and asphalt is the main cause of the urban heat island effect, primarily becoming apparent through increased land surface temperature. This study examined the effect of different urban land cover types on the land surface temperature using MODIS, Landsat ETM+ and RapidEye satellite data. As a result, the remote sensing based land surface temperature showed a marked difference according to the land use pattern in the case study of Ilsan new city. The high-rise apartment residential districts with less building-to-land ratio and higher green area ratio revealed lower land surface temperature than the low-story single-family housing districts characterized by relatively high building-to-land ratio and low green area ratio. From the view of climate zone and land cover types, there is a strong linear correlation between the impervious land cover ratio and the land surface temperature; the land surface temperature increases as the impervious built-up areas expand. In contrast, vegetation;water and shadow areas affect the decrease of land surface temperature. There is also a negative (-) correlation between NDVI and land surface temperature but the seasonal variation of NDVI can be hardly corrected.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.2
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• pp.237-249
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• 2002

The wall system that is composed only of reinforced concrete walls and slabs is adopted on many high-rise apartment buildings recently constructed. In the apartment buildings, a shear wall may have one or mote openings for functional reasons. Many researches on the analysis of shear wall with openings were performed. But, some restrictions prevent those research results being applied to practical analysis and design procedure. It is necessary to use subdivided finite elements lot accurate analysis of the wall system with openings. But it would cost tremendous amount of analysis time and computer memory if the entire building structure is subdivided into a finer mesh. An efficient analysis method which can be used regardless of the number, size and location of openings is proposed in this study. The analysis method uses super element, matrix condensation technique and fictitious beam technique. Analyses of example structures having various types of openings were performed to verify the efficiency of proposed method. It was confirmed that the proposed method have outstanding accuracy with drastically reduced time and computer memory from the analyses of example structures.