• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.11-12
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• 2013

It is required to response to the demand for new space due to high density of population and buildings in urban area. In particular, in case of big cities such as Seoul where the lack of new construction site due to the depletion of available space, existing buildings must be demolished for new construction. Utilization of urban underground space can be an alternative to solve for urban space problems. There are applications of underpinning methods using micropiles for existing buildings. Sometimes, the difficulties come from the compact space available for new foundation underneath the existing ones. In this paper, a novel underpinning method is introduced which can solve the space restriction problems underneath existing columns.

• Fire Science and Engineering
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• v.4 no.1
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• pp.13-19
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• 1990

Recently, the expansion of underground shopping street has a tendency to make a large maze in urban underground space. As the passers -by in underground streets have little information about these spaces, there can be a great danger at fire. From this point of view, this study aims at offering the basic data which needs to make a reasonable planning of escape facilities of underground shopping street. Therefore, safe performance evaluation program is developed for evaluating inhabitants' safety at each model. This program is composed of systematic equations which generalize each phenomenon at fire.

• Fire Science and Engineering
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• v.16 no.4
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• pp.49-58
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• 2002

A large number of accidents at an underground place have been happening, including the gas explosion under construction of subway; the fires of underground utility and underground shopping malls, and other explosion, at home and abroad recently. These accidents make the function of a city ineffective due to the paralyses of electricity and communications net as well as the loss of property and cause people to feel unsecured with accompaniment of a heavy of toll of lives. This research will show evaluation methods of a numerical value of expected average loss space of combustion with the use of probability in order to present potential risk of combustion growth that underground space might cause, and how designer decides a system that enables us to compare and evaluate relatively the effectiveness of measures for preventing burning by calculating the expansion route and the damage size of burning in case of fire.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.254-255
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• 2013

New Seoul city hall completed in 1926 is a registered historical building. The remodeling plan has been developed for the expansion after the review by the governmental agency. Based on the plan, a new city hall should be constructed behind the current city hall while the facade, the main lobby and the dorm structure of the existing building, A new construction method, FUSEM, has been developed for this mission for the safety of the historical structure.

• Journal of the Korean Institute of Educational Facilities
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• v.22 no.1
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• pp.25-36
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• 2015

Historically, college campuses have played a role of a city, and the development pattern of various forms and functions of cities was found in the growth stages of campuses as well. In this way, campuses developed in close relationships with our lives and such a characteristic can be confirmed in a number of cases in and out of the country. The strategic concept of such expansion is shown in the strategic classification through a master plan. This research examines concepts of major universities in the metropolitan area of Korea for promoting campus expansion and proposes implications through them. The results drawn from the research are as follows. Firstly, various developmental directions should be sought in aspects of planning, programming and economics for campus expansion with the complex application of such factors. Secondly, the multi-campus strategy of past localization era is changing into the concept of forming a global campus materializing itself as the planning strategy of internal campus. Thirdly, the physical barrier is being dissolved as a way to promote the relationship with local communities, and particularly, the management strategy of constructing new buildings in connection with local communities is the leading measure of materialization. Lastly, the development of underground space is actively carried out due to the limitation of ground physical space through which a role of establishing new campus order along with securing space is pursued.

• Tunnel and Underground Space
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• v.17 no.6
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• pp.475-483
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• 2007

With increasing demand for LNG as energy resources and need for $CO_2$ sequestration as greenhouse gas, more storage facilities are required in Korea. Due to the recent acute safety concerns and land shortage, storage facilities tend to be located underground. In design and construction of underground storage for low and high temperature materials, besides their mechanical characteristics, the thermal characteristics of rock under temperature variation should be understood. In this study, laboratory experiments for the measurement of the thermal expansion coefficient of rock were performed using strain gauge in consideration of the particle size of mineral and experiment temperature range. Experiment results show that thermal expansion coefficient decreased as the temperature decreases. In addition, linear thermal expansion coefficient was developed for typical Korean rocks such as granite. The results of this study can be utilized for the evaluation of thermal propagation in rock mass and the thermo-mechanical stability of underground facilities.

• Journal of the Korean GEO-environmental Society
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• v.21 no.8
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• pp.5-13
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• 2020

During the construction of underground space expansion of old facilities, it is necessary to secure temporary residence space for existing residents as well as noise and vibration issues during construction, and in the case of commercial, industrial, and social use, damage is expected from suspension of the use of facilities. There is a need for a technology that minimizes noise and vibration during underground expansion, enabling the use of existing facilities even during construction. In this study, a practical underground extension model is proposed by analyzing the behavior of the temporary structure and the surrounding ground as a result of measurement at each construction stage for a actual construction site. In order to solve the problems that occurred during construction, the basement slabs were placed in advance after the initial excavation. The measurement results (building inclinometer, crack measurement system, structure inclinometer and surface settlement meter) at the site were reviewed to analyze the behavior of the temporary structure and surrounding ground. As a result, it was confirmed that the inclinometer of the building and the structural inclinometer showed a tendency that the displacement after the slab line was placed was reduced or converged. The placement of basement slabs during underground extension not only relived the noise and vibration problems during construction, but also secured the stability of structures.

• Tunnel and Underground Space
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• v.8 no.1
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• pp.26-36
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• 1998

To assess the groundwater flow near high-level radioactive waste repositories, it is important to understand the effect of coupling among thermal, hydraulic, and mechanical effects. In this paper, detailed mathematical approach to model the groundwater flow near the waste form surrounded by buffer, influenced by decay heat of radioactive waste along with stress change is developed. Two cases(1) before the full expansion of buffer and (2) after the full expansion of buffer are modelled. Based on the mathematical models in this paper, detailed numerical study shall be pursued later.

• Journal of Auto-vehicle Safety Association
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• v.13 no.4
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• pp.73-80
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• 2021

Recently, Korea has established a plan for the supply of hydrogen vehicles and is promoting the expansion of the supply. Risk factors for hydrogen vehicles are hydrogen leakage, jet fire, and explosion. Therefore Safety measures are necessary for this hazard. In addition, risks in semi-closed spaces such as tunnels, underground roads, and underground parking lots should be analyzed. In this study, an explosion experiment was conducted on a hydrogen tank used in a hydrogen vehicle to analyze the risk of a hydrogen vehicle explosion accident that may occur in a semi-closed space. As results, the effect on the structure and the human body was analyzed using the overpressure and impulse values for each distance generated during the explosion.

• Tunnel and Underground Space
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• v.18 no.6
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• pp.436-446
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• 2008

The volumetric expansion ratio of rock mass on the subsidence occurrence area can explain why the depth of the surface subsidence is lower than the height of an opening; it is because the empty space of the gangway is filled with the broken rock. But, until now, when the surface subsidence mechanism is studied without consideration of the volumetric expansion ratio, it is usually overlooked that the amount of subsidence occurrence can be overestimated. Therefore, in this study, the authors researched the subsidence occurrence mechanism with a new theoretical approaching method. The volumetric expansion ratio obtained from this method has been applied to the numerical simulations. The authors adopted the UDEC(Universal Distinct Element Code) for their discontinuum numerical analysis, because this program has an advantage for analyzing the behavior of rock discontinuities.