• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.4
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• pp.657-669
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• 2018

In recent years, the development of complex urban areas has become saturated and much attention has been focused on the development of underground space, and deep excavation is frequently performed in order to increase the utilization of underground space due to the enlargement of buildings and the high rise of buildings. Therefore, in this study, we tried to understand the behavior of the braced wall and the behavior of the tunnel adjacent to the wall according to the stiffness of the wall and the distance between the tunnel and wall. As a result of the study, the deformation of the braced wall tended to decrease with increasing the stiffness of the wall, and the axial force acting on the struts was also different according to the stiffness of braced wall. When the stiffness of the braced wall is small (2 mm), the point at which the axial force of the braces maximizes is near 0.3H of the wall. When the stiffness of the braced wall is large (5 mm), the axial force is maximum at around 0.7H of the wall. Also, the tunnel convergence occurred more clearly when the separation distance from the braced wall was closer, the stiffness of the wall was smaller, and the tunnel convergence was concentrated to the lower right part. The ground settlement due to the excavation of the ground tended to decrease as the distance between tunnel and braced wall was closer to that of the tunnel, which is considered to be influenced by the stiffness of the tunnel.

• Earthquakes and Structures
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• v.12 no.1
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• pp.1-12
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• 2017

Historical earthquakes have shown that successive seismic events may occur in regions of high seismicity. Such a sequence of earthquakes has the potential to increase the damage level of the structures, since any rehabilitation between the successive ground motions is practically impossible due to lack of time. Few studies about this issue can be found in literature, most of which focused their attention on the seismic response of SDOF systems or planar frame structures. The aim of the present study is to examine the impact of seismic sequences on the damage level of 3D multistorey R/C buildings with various structural systems. For the purposes of the above investigation a comprehensive assessment is conducted using three double-symmetric and three asymmetric in plan medium-rise R/C buildings, which are designed on the basis of the current seismic codes. The buildings are analyzed by nonlinear time response analysis using 80 bidirectional seismic sequences. In order to account for the variable orientation of the seismic motion, the two horizontal accelerograms of each earthquake record are applied along horizontal orthogonal axes forming 12 different angles with the structural axes. The assessment of the results revealed that successive ground motions can lead to significant increase of the structural damage compared to the damage caused by the corresponding single seismic events. Furthermore, the incident angle can radically alter the successive earthquake phenomenon depending on the special characteristics of the structure, the number of the sequential earthquakes, as well as the distance of the record from the fault.

• Korean Journal of Remote Sensing
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• v.36 no.5_1
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• pp.693-706
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• 2020

For ten meteorological observatories running an automated synoptic observing system (ASOS), we classified the observation environments into five classes based on the World Meteorological Organization (WMO) classification guidelines. Obstacles (such as topography and buildings) and land-cover types were the main factors in evaluating the observation environments for the sunshine duration, air-temperature, and surface wind. We used the digital maps of topography, buildings, and land-cover types. The observation environment of the sunshine duration was most affected by the surrounding buildings when the solar altitude angle was low around the sunrise and sunset. The air-temperature observation environment was determined based on not only the solar altitude angle but the distance between the heat/water source and ASOS. There was no water source around the ASOSs considered in this study. Heat sources located near some ASOSs were not large enough to affect the observation environment. We evaluated the surface wind observation environment based on the roughness length around the ASOS and the distance between surrounding buildings and the ASOS. Most ASOSs lay at a higher altitude than the surroundings and the roughness lengths around the ASOSs were small enough to satisfy the condition for the best level.

• Journal of the Korean Institute of Educational Facilities
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• v.24 no.2
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• pp.3-10
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• 2017

This study compared evacuation effectiveness between the conventional school auditorium plan and a suggested hypothetical plan that was generated by a mathematical model, which is commonly applied in the field of industrial engineering. Recent school buildings became much more complicated in floor planning due to new social needs and modern curriculum than the old days. Nevertheless, architect's approach to floor composition in terms of fire emergency evacuation planning, still has no relation to optimized effective but relies more on an conventional school planning. Therefore, since school buildings are much more likely to be exposed to any fire related events than any other building types, emergency exit effectiveness based on spatial composition has to be seriously evaluated with a scientific method. The algorithm, which acquires the number of persons in each spatial type(node) per floor and the minimum physical distance between spatial types(arc), can propose the most optimized spatial layout per floor regarding emergency evacuation event. Consequently, this study evaluated school's fire exit effectiveness focusing on auditorium area with the scientific tool and suggested the most reliable spatial layout regarding possibile emergency evacuation event.

• Journal of the Korean Institute of Educational Facilities
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• v.23 no.3
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• pp.3-10
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• 2016

This study compared evacuation effectiveness between the conventional school floor plan and a suggested hypothetical floor plan that was generated by a mathematical model that is commonly applied in the field of industrial engineering. Recent school buildings became much more complicated in floor planning due to the new educational system and modern curriculum than the old days. Nevertheless, architect's approach to floor composition in terms of fire emergency evacuation planning, still has no relation to optimized effective but relies more on a conventional school planning. Therefore, since elementary school buildings are much more likely to be exposed to any fire related events than middle school or high-school, emergency exit effectiveness based on spatial composition has to be seriously evaluated with a scientific method. The algorithm, which acquires the number of persons in each spatial type (node) per floor and the minimum physical distance between spatial types (arc), can propose the most optimized spatial compositing per floor regarding emergency evacuation event. Consequently, this study evaluated elementary school's fire exit effectiveness with the scientific tool and suggested the most reliable spatial composition per floor regarding possibile emergency evacuation event.

• Journal of Korean Society of Steel Construction
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• v.16 no.3 s.70
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• pp.305-314
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• 2004

Many residential buildings and mixed-use (i.e., residential and commercial) buildings that are currently under construction in the country mainly consist of building clusters rather than single structures. Recent trends show single buildings that actually consist of two houses. The lower part of the building consists of a single dwelling space. However, the upper part of the building is split into two dwellings, considering the aspects of commercialism and appearance, such as ventilation and lighting. These tall and complex buildings not only have low mass and damping. They also depend on wind loads for their structural stability and serviceability, due to the interaction between the building groups and the wind. In architectural design, however, the interaction effects among neighboring houses within a building group have yet to be identified. In addition, it is difficult to predict these interaction effects. In this regard, this thesis aims to model patterns of architecture, which consist of two houses that are existing or under construction. Current structures are investigated by comparing their wind-reduced response interaction effects, based on the measured distance between two buildings, and the acceleration response through the wind tunnel test. The results of this study are expected to provide basic data for wind-induced response interaction effects of building groups. Furthermore, the outcomes are also intended to be used as data for more rational and economical structure design.

• Korean Journal of Hazardous Materials
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• v.6 no.2
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• pp.7-12
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• 2018

Hydrochloric acid is a highly corrosive toxic substance and requires proper safety to minimize damage in case of leakage. Among the various risk-reduction facilities, the dike is a typical safety facility installed to protect the surrounding buildings and facilities by preventing the external spread of hazardous materials from the storage tank. In this study, the KORA program was used to assume leakage accident of hydrochloric acid storage tank. At this time, the extent of the damage effects of ERPG-2 were assessed for each of the three separation distance between the storage tank and the dike. The study found that the smaller the separation distance between the dike and the storage tank, the smaller the extent of damage caused by hydrochloric acid leakage, and the greater the impact of indoor conditions under the same conditions. Through this process, we are going to assist in selecting locations and installing facilities for new and existing businesses.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.4
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• pp.605-612
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• 2017

One of the biggest environmental issues that our world has been facing is climate change. In order to cope with such environmental issues, the world is putting a great deal of effort into energy conservation. The building sector, in particular, consumes 36% of the energy consumed worldwide and emits considerable amount of greenhouse gases. Therefore, introduction of renewable energies in the building sector is highly recommended. Renewable energy sources that can be utilized in the building sector include sunlight, solar heat, geothermal heat, fuel cells and wind power. The wind power generation system which converts wind energy into electrical energy has advantages in that wind is an unlimited and pollution-free resource. It is suitable to be connected to existing buildings because many years of operational experience and the enhanced stability of the system have made it possible to downsize the electrical generator. In case of existing buildings, it is necessary to consider the live loads of the buildings to connect the wind power generation system. This paper, through the connection of the wind power generation with existing buildings, promotes reduction of greenhouse gas emissions and energy independence by reducing energy consumption in the building sector. In order to connect the wind power generation system with an exciting building, the live load of the building and the area of the rooftop should be considered. The installable model is selected by comparing the live load of the building and the load of the wind power generation system. The maximum number of the wind turbines that can be installed is obtained by considering the separation distance between the wind turbines within the area of the rooftop. Installations are divided into single installations and multiple installations of two different types of wind turbines. After determining the maximum installable number, the optimal model that can achieve the maximum annual power generation will be selected by comparing the respective total annual amount of the power generation of different models.

• Structural Engineering and Mechanics
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• v.51 no.2
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• pp.277-297
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• 2014

Since the isolation bearings undergo large displacements in base-isolated structures, impact with adjacent structures is inevitable. Therefore, in this investigation, the effect of impact on seismic response of isolated structures mounted on double concave friction pendulum (DCFP) bearings subjected to near field ground motions is considered. A non-linear viscoelastic model of collision is used to simulate structural pounding more accurately. 2-, 4- and 8-story base-isolated buildings adjacent to fixed-base structures are modeled and the coupled differential equations of motion related to these isolated systems are solved in the MATLAB environment using the SIMULINK toolbox. The variation of seismic responses such as base shear, displacement in the isolation system and superstructure (top floor) is computed to study the impact condition. Also, the effects of variation of system parameters: isolation period, superstructure period, size of seismic gap between two structures, radius of curvature of the sliding surface and friction coefficient of isolator are contemplated in this study. It is concluded that the normalized base shear, bearing and top floor displacement increase due to impact with adjacent structure. When the distance between two structures decreases, the base shear and displacement increase comparing to no impact condition. Besides, the increase in friction coefficient difference also causes the normalized base shear and displacement in isolation system and superstructure increase in comparison with bi-linear hysteretic behavior of base isolation system. Totally, the comparison of results indicates that the changes in values of friction coefficient have more significant effects on 2-story building than 4- and 8-story buildings.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.1039-1042
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• 2007

The number of vehicle has been increased due to growth of economy. Consequently, the needs for parking area has been increasing. there is a serious problem in aged-apartments. It result from observing a parking lot law at that times. That is the reason why residents demand parking lot expansion. Parking lot addition is being studied on a lots different standpoint to solve the present parking lot condition. Parking lot expansion is limited by housing complex characteristics. This study analyzed the housing complex characteristics of aged-apartment. It is analyzed that the number of house holders, distance between buildings, and level of site for finding housing complex characteristics. The result are as follows. the complex lower than 300 households is about 35% in the Number of households. The buildings which has a moving distance from 41m to 50 is nearly 23%. Them the 멕스둣 house located on the flat is 82%. This study will become a reference data for the parking lot expansion.