• Fire Science and Engineering
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• v.33 no.2
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• pp.85-97
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• 2019

Today, building constructions are becoming larger, higher, deeper, and complex to improve quality of human life and meet various needs. As a result, new design space for non - typically standardized space has been created, and targets for performance-based design are also becoming increased. An evacuation safety evaluation of performance-based design should be compared with ASET and RSET estimation so that the value of RSET does not exceed the value of ASET. However, there is a problem that it is difficult to secure the safety with using the performance-based design evaluation method currently in use, especially in case of the underground parking lot, because it has wide compartment area and various routes for evacuation. Therefore, in order to overcome these problems, this paper first investigates the simulation setting method of the performance-based design that is currently in use, and then conducts two fire simulations and three evacuation simulations for underground parking lots each time, so performs the evacuation safety evaluationin total six cases of situations. Here this paper analyzes the problem with comparative evaluation research and suggests the better solution for improved evacuation safety evaluation of performance-based design.

• Journal of Korean Tunnelling and Underground Space Association
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• v.12 no.4
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• pp.321-328
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• 2010

The study performed an actual fire experiment in order to propose the heat release rate of automobile that is the most basic architectural element for the fire safety design in a tunnel, whose importance has been recognized as the underground traffic tunnels are planned in Korean metropolitan cities. The heat release rate of a van is measured by the large scale calorimeter, in which the law of oxygen consumption is applied, and the fire expansion characteristics in a tunnel by placing two passenger cars nearby one another in the tunnel. As the results, the heat release rate of the van was revealed to be 5.9 MW, and carbon monoxide was emitted 482 ppm at a maximum. In case of two passenger car experiment for the fire expansion characteristics, the adjacent car was ignited about 3 minutes 30 seconds after the fire occurrence, and the complete fire was developed after 15 minutes. The maximum heat release was 9 MW. The results from the actual fire experiment can be an important input data for future quantitative analysis as well as an element applicable to a tunnel disaster preventive equipment design.

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.4
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• pp.337-346
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• 2020

Traffic jam and congestion in urban areas has caused the need to improve the utility of underground space. In response, research on underground structures is increasingly being conducted. Notably, a double-deck tunnel is one of the most widely used of all those underground structures. This double-deck tunnel is separated by the middle slab into the upper and lower roadways. Both vehicle load and earthquake load cause the middle slab to exhibit dynamic behavior. Earthquake-related response characteristics, in particular, are highly complex and difficult to interpret in a theoretical context, and thus experimental research is required. The aim of the present study is to assess the stability of a double-deck tunnel's middle slab of the Collapse Prevention Level and Seismic Category 1 with regard to the presence of vibration-damping Rubber Bearings. In vibration table tests, the ratio of similitude was set to 1/4. Linings and vibrating platforms were fixed during scaled model tests to represent the integrated behavior of the ground and the applied models. In doing so, it was possible to minimize relative behavior. The standard TBM cross-section for the virtual double-deck tunnel was selected as a test subject. The level of ground motion exerted on the bedrock was set to 0.154 g (artificial seismic wave, Collapse Prevention Level and Seismic Category 1). A seismic wave with the maximum acceleration of 0.154 g was applied to the vibration table input (bedrock) to analyze resultant amplification in the models. As a result, the seismic stability of the middle slab was evaluated and analyzed with respect to the presence of vibration-damping rubber bearings. It was confirmed that the presence of vibration-damping rubber bearings improved its earthquake acceleration damping performance by up to 40%.

• Tunnel and Underground Space
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• v.25 no.4
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• pp.373-382
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• 2015

This study presents a method to calculate carbon dioxide emissions of diesel vehicles operated in an underground mine using Geographic Information Systems (GIS). An underground limestone mine in Korea was selected as the study area. A GIS database was constructed to represent the haulage roads as a 3D vector network. The speed of dump trucks at each haulage road was investigated to determine the carbon dioxide emission factor. The amount of carbon dioxide emissions related to the truck's haulage work could be calculated by considering the carbon dioxide emission factor at each haulage road and the haulage distance determined by GIS-based optimal route analysis. Because diesel vehicles are widely utilized in the mining industry, the method proposed in this study can be used and further improved to calculate the amount of carbon dioxide emissions in mining sites.

• Journal of Internet Computing and Services
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• v.23 no.3
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• pp.137-145
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• 2022

The logistics of ammunition stored in the underground ammunition warehouse has more difficulties than the logistics of ammunition stored on the ground due to the nature of the storage space. This study was conducted to solve the logistics of underground ammunition warehouse by improving these problems. And six items such as guard, safety, environment, supply system, equipment, facilities, and life management were selected for the improvement of logistics. And AHP was analyzed by Expert Choice program by conducting a survey to experts. As a result of the analysis, it was confirmed that the importance was high in the order of safety, guard, life management, equipment facilities, supply system, and environment. Based on the selected items and the results of the survey, a plan to build a network-based integrated platform that can improve logistics in an underground ammunition warehouse was presented. This study will be used as a basis for the establishment of an integrated platform when constructing an underground ammunition warehouse in the future. This study can be applied to storage facilities that store other materials in the military, and it is expected to be applied to large commercial storage facilities.

• Spatial Information Research
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• v.23 no.3
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• pp.113-122
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• 2015

Recently, according to developing advanced construction technologies, buildings has been enlarged such as high-rise buildings or complex buildings associated with underground facilities. The number of indoor activity population has increased very quickly. Because of that, technical requirements for Indoor location based service (Indoor LBS) also have been increased. Although indoor networks have to be constructed for efficient LBSs in indoor space based on OGC IndoorGML, it is not suitable for large and complex space to apply the simple network structure to constructing indoor navigation networks. The indoor navigation network has to be constructed according to logical, physical, and functional constraints for indoor space. In order to do that, subspacing methods are required to partition large and complex indoor space into proper size of subspace. In this paper, we proposed the basic requirements of subspacing in indoor space for creating efficient indoor network, as well the work process of subspacing in indoor space.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.4
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• pp.343-350
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• 2022

The computerization project for underground facilities in Korea began in earnest after the city gas explosion in Seoul in 1994, and the Daegu subway explosion in 1995. As such a large-scale gas explosion accident caused enormous economic loss including human casualties and potential benefits, the need for computerized for efficient management of underground facilities was greatly emphasized in society. Meantime, computerization of underground facilities has been carried out according to the basic plan for building national geographic information system. In this study, problems were identified based on the current status of construction and management of underground facility information, as well as laws and regulations, and directions for establishing quality standards were presented. In addition, construction work standards such as 「Public Survey Work Regulations」, design standards, standard specifications, and technical specifications, gas technology standards, design standards, and communication works so that underground facility information can be linked and utilized in construction work by examining the linkage of the underground facilities, the targets that can be used for quality level information on underground facilities were derived, and a proposal to revise the construction standards was presented. In the future, if the quality standards are established, it is expected that the accuracy and utilization in the construction field will be increased.

• Journal of IKEEE
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• v.23 no.3
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• pp.762-767
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• 2019

The plane-wave shielding effectiveness is typically measured for horizontal and vertical polarizations using a linearly polarized antenna. However, this typical measurement method results in big evaluation fees due to very long measurement time as well as huge idle space for maintenance, these problems is more severe especially in large shielded enclosures such as EMP protection facilities to be built in indoor buildings and underground. This paper describes the design and fabrication process and results of a planar log-spiral antenna applicable to the evaluation of the electromagnetic shielding effectiveness of a large EMP protection facility. Since the proposed antenna has a circular polarization, there is no need to separately measure the horizontal and vertical polarizations. Therefore, the measurement time can be shortened by more than 1/2, and further, its small volume with a planar structure can reduce greatly idle space required for the maintenance.

• Journal of Korean Tunnelling and Underground Space Association
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• v.11 no.1
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• pp.1-9
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• 2009

When a rock slope is excavated adjacent to a existing tunnel, the behavior of the existing tunnel in the jointed rock masses is greatly influenced by the joint conditions and slope status. In this study, the effects of joint dip and slope angle close to a tunnel are investigated through a large scale model using a biaxial test equipment ($3.1\;m\;{\times}\;3.1\;m\;{\times}\;0.50\;m$ (width $\times$ height $\times$ length)). The jointed rock masses were built by concrete blocks. The diameter of the modeled tunnel is 0.6 m and the dip angles of joint vary in the range of $0-90^{\circ}$. In addition, the excavated slope angle varies within $30{\sim}90^{\circ}$. Deformational behaviors of the tunnel were analyzed in consideration of joint dip and slope angle. With increase of the joint dip and slope angle, the magnitude of tunnel distortion and the moment of tunnel lining were increased. Rock mass displacement in horizontal was also dependent on the joint dip and the excavated slope angle, which indicated the optimal slope reinforcement for a specific rock mass conditions.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.3
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• pp.640-655
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• 2018

Recently, the construction of the urban area has been rapidly increasing, and the excavation work of the ground has been frequently performed at the upper part of the existing underground structures. Especially, when the structure is constructed after the excavation of the ground, the loading and unloading process in the ground under the excavation basement can affect the existing underground structures. Therefore, in order to maintain the stability of the existing underground structure due to the excavation of the ground, it is necessary to accurately grasp the influence of the excavation and the structure load in the adjoining part. In this study, the effect of the excavation of the ground and the new structure load on the existing tunnel was experimentally implemented and the influence of the adjacent construction on the existing tunnel was investigated. For this purpose a large testing model with 1/5 scale of the actual size was manufactured. The influence of ground excavation, width of the load due to new structure, and distance between centers of tunnel and of excavation on the existing tunnel was investigated. In this study, it was confirmed that the influence on the existing tunnel gets larger, as the excavation depth get deeper. At the same distance, it was confirmed that the tunnel displacement increased up to three times according to the increase of the building load width. That is, the load width influences the existing tunnel larger than the excavation depth. As the impact of the distance between centers of tunnel and of excavation, it was confirmed that tunnel crown displacement decreased by 48%. The result showed that a tunnel is located in the range of 1D (D: tunnel diameter) from the center of excavation, the effect of excavation is the largest.