• Earthquakes and Structures
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• v.1 no.3
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• pp.231-252
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• 2010

Previous research on pounding between seismically isolated buildings during earthquakes has been focused on impacts at the bases of structures and the effect of simultaneous interactions at the bases and at the superstructures has not been studied in details. In this paper, the seismic responses of adjacent buildings supported on different or similar base systems considering impacts between bases and superstructures are numerically investigated. The study is carried out in three parts for the two types of adjacent buildings: (i) both structures have fixed bases; (ii) one structure has fixed base and the other is seismically isolated and (iii) both structures have base isolation systems. The results of the study indicate that the pounding-involved responses of the buildings depend mainly on the type of structural base systems and on the structural parameters of both buildings. For the base-isolated building, the variation of the peak accelerations and displacements of the storeys have been found to be relatively low. On the other hand, significant differences have been observed for the fixed base building. The results of the parametric study conducted for different values of the gap size between colliding structures show the reduction in the peak base displacements as the gap distance decreases.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.1 s.108
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• pp.49-57
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• 2005

The aim of this study was to explain the relationship between the landscape organization and evaluating factors to harmonize the buildings with natural landscape using the landscape simulation models (near view less than $100{\cal}m$) controled the distance and obtain some knowledges about the introduction of buildings into the recreation forest. Through this study, the results were summarized as follow ;1) As the distance got to be near, the evaluation of comprehensive scenery and natural quality became low. 2) At the view points according to the distance the clear landscape organization showed a high value of scenery in comparison with the simple landscape organization, 3) As the coniferous forest showed more high value in comparison with the deciduous forest, the forest type surrounding cottage is important factor evaluating the landscape in the recreation forest area.

• Journal of the Korean Institute of Landscape Architecture
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• v.25 no.3
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• pp.12-24
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• 1997

One argument of this study is that the policy to handle and landscape of cultural and historical property had to do with people's visual preferences. This study seeks to investigate people's visual preferences toward the landscape of cultural /historical property, specifically dealing with 'Namdaemun', which is the first class cultural property of Korea. People's visual preference was specifically examined into the four specific concepts : 'visual identity','harmony','beauty of the target property', and 'overall beauty'. Two objective variables, such as, 'distance' between the viewer and the cultural property, and 'height' of background buildings were considered possible predictors of the four visual preference variables. Photos of 'Namdaemun' were taken at three different directions and at three different distances. The photographed images of 'Namdaemun' were transferred ito the digitalized graphic images, where the height of background buildings was artificially changed and simulated. The simulated visual images were taken into the slides again. A total of 59 students of the Department of Landscape architecture at Seoul City University were sampled as subjects. A series of 17 slides were shown to the subjects four times. The subjects were asked to check their preference ratings concerning the four concepts on a 7-point Likert scale. The results found in this study were as follows : 1) In the results of ANOVA, it was clear that people visually preferred the view where the height of background buildings were lower than 15 floors to the view of more than 15 floors . 2) From the results of the path analysis, it was found that 'harmony','visual identity' and 'beauty of the target property' were direct predictors of 'the overall beauty'. The 'height ' of background buildings and the viewer's 'distance' were not found to be direct predictors, however, they demonstrated their effects on 'the overall beauty' through the other variable, which were direct predictors of 'the overall beauty'. In sum, the longer the distance and the higher the background buildings, the lower people's preference with the 'overall beauty'. These indirect paths, in turn, also explain why and how the 'height' of background buildings and the viewer's 'distance' negatively influence the 'overall beauty'. An implication from the these results is that when the height of background buildings were not controllable, there would be some other strategies for improving people's visual preference toward the historical /cultural view. To increase 'visual identity' of the cultural property, for example, changing colors of the cultural property or increasing the lighting level, etc., would be one strategy, since the increased 'visual identity' will, in turn, increase 'the overall beauty'.

• Earthquakes and Structures
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• v.15 no.4
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• pp.395-402
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• 2018

Floor location of adjacent buildings may be different in terms of height elevation, and thus, the slab may hit on the columns of adjacent insufficiently separated buildings during severe ground motions. Such impacts, often referred to as mid-column pounding, can be catastrophic. Substantial pounding damage or even total collapse of structures was often observed in large amount of adjacent low rise buildings. The research on the mid-column pounding between low rise buildings is in urgency need. In present study, the responses of two adjacent low rise buildings with unequal heights and different dynamic properties have been analyzed. Parametric studies have also been conducted to assess the influence of story height difference, gap distance and input direction of ground motion on the effect of structural pounding response. Another emphasis of this study is to analyze the near-fault effect, which is important for the structures located in the near-fault area. The analysis results show that collisions exhibit significant influence on the local shear force response of the column suffering impact. Because of asymmetric configuration of systems, the structural seismic behavior is distinct by varying the incident directions of the ground motions. Results also show that near-fault earthquakes induced ground motions can cause more significant effect on the pounding responses.

• Journal of the Korean housing association
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• v.15 no.2
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• pp.55-62
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• 2004

Apartment design in residential Area is restricted by building distance limit code. Building distance limit decreases gradually to the 0.8H(height), and residential area has 250% site area ratio by building code, so site using has become efficient. In this study, examine the relationship between present building distance limit and right of daylighting environment by computer simulation. As well, high-rise residential officetel and multipurpose residential building becomes increase in commercial non-residential area. In the domestic, residential type multipurpose building made at the business area or central business area has 400∼800% site area ratio by building code. However, at a dweller's point of view, there are much lacks of environmental consideration to provide suitable daylighting environment. And, POE: Post Occupancy Evaluation is not completed yet. In this study, however, progress architectural environment prediction, basis by right of daylighting, and examine the possibility of daylighting by architectural distance limit code in residental area and by high-rise, high-density residential building in non-residental downtown area.

• Structural Engineering and Mechanics
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• v.83 no.2
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• pp.153-166
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• 2022

Structural pounding due to strong seismic excitations can result in severe damage or even collapse of colliding structures. Many researchers focused on studying the mutual pounding between two adjacent structures while very few researches were concerned with the pounding of a series of structures. This paper aims to study the pounding effect on a series of four buildings having different natural frequencies. The paper also investigates the effect of different arrangements of the four buildings on their pounding response. For this, a mathematical model was constructed using Matlab code where, pounding was modeled using a contact force-based approach. A Non-Linear viscoelastic (Hertzdamp) contact element was used and activated only during the approach period of collision. The mathematical model was validated by comparing its prediction versus experimental results on three adjacent buildings. Then the model was used to study the pounding between four adjacent structures arranged in different sequences according to their natural frequencies. The results revealed that increasing the gap distance generally led to decrease the peak responses of the towers. Such response is somehow different from that predicted earlier by the authors for the case of three adjacent buildings. Moreover, the arrangement of towers has a significant effect on their pounding response. Significant difference between the natural frequencies of adjacent structures increases the pounding forces especially when the more flexible buildings are located at the outer edge of the series. The study points out the need for further researches on buildings in series to gain a better understanding of such complex phenomena.

• KIEAE Journal
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• v.12 no.1
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• pp.29-34
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• 2012

As a series of studies about natural ventilation driven by wind in basement parking lots of apartment, the influence of opening size and surrounding buildings on ventilation rate was analyzed. Natural ventilation in underground parking lots almost rely on wind than temperature difference. To investigate natural ventilation driven by wind, wind tunnel tests by using scale model and tracer gas method were conducted. $CO_2$-gas concentration was measured, natural ventilation rates were calculated. The experimental results showed that the natural ventilation rate is more reliable to wind direction and surrounding building than opening size and distance between buildings. It was verified that surrounding buildings play a principal role in increasing air flow rate by accelerating wind speed, and growing turbulence intensity. And it showed that ventilation performance is able to be increased by oblique wind to entrance ramp than head on wind in underground parking lots with surrounding buildings.

• Earthquakes and Structures
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• v.22 no.3
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• pp.289-304
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• 2022

During strong ground motions, adjacent structures with insufficient separation distances collide with each other causing considerable architectural and structural damage or collapse of the whole structure. Generally, existing design procedures for determining the separation distance between adjacent buildings subjected to structural pounding are based on approximations of the buildings' peak relative displacement. These procedures are based on unknown safety levels. This paper attempts to evaluate the influence of foundation flexibility on the structural seismic response by considering the variability in the system and uncertainties in the ground motion characteristics through comprehensive numerical simulations. Actually, the aim of this study is to evaluate the influence of foundation flexibility on probabilistic evaluation of structural pounding. A Hertz-damp pounding force model has been considered in order to effectively capture impact forces during collisions. In total, 5.25 million time-history analyses were performed over the adopted models using an ensemble of 25 ground motions as seismic input within OpenSees software. The results of the study indicate that the soil-structure interaction significantly influences the pounding-involved responses of adjacent structures during earthquakes and generally increases the pounding probability.

• Journal of the Korean housing association
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• v.17 no.2
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• pp.107-115
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• 2006

This study examined the equivocalness of the standard legislation regarding the present situation of the sunshine-related law to reduce the trespass of the right of sunshine. In order to make more specific standard about that law, it was intended to suggest the distance ratio between apartment houses by the regional groups, the angle of building's direction and the gradient of the ground with the process of subdividing the existing regulation.

• Journal of the Korea Safety Management & Science
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• v.15 no.1
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• pp.61-68
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• 2013

In the case of the fire to the exterior of the building through openings, the openings of the adjacent building are exposed to the risk of combustion expanding and factors that affect the combustion in the radiant heat and direct flame. Recent five years, fire of the adjacent building indicated that incidence of the 5,134(2.27%) among total 225,934 cases occurred The damage scale of fire expanded was lower than in a single building but casualties(5.46%) and property(25.0%) damage were higher. Therefore, this study provides to analyze the operating status for fire protection equipment of fire-preventing area in the Seoul and to apply measures to improve fire protection equipment according to narrow the distance between the building openings studied.