• International Journal of Railway
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• v.9 no.1
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• pp.21-26
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• 2016

When excavation under existing structure is planned for a new construction project, the underpinning method is one of the most applicable construction methods. This study introduces a new modified underpinning method which is applied to construct a new subway line in Seoul Metropolitan. The new subway line was designed to pass underneath the existing subway line. Existing subway line carries about 2 million passengers daily, which is 33% of total passengers using subway in Seoul, and is the only circulation line in Seoul. Subway trains are passing 540 times through this section in a day. By applying a new underpinning method, the subway box structure of line is exposed 54m in the air supported by bearing piles. The proposed method was carefully monitored using heavy instrumentation system during construction. This study proposed and verified the application of the modified underpinning method, which can reduce construction period by 1.5 times and the construction cost by 1.2 times comparing with conventional method. The importance of considering construction sequence is investigated and verified by analyzed data non-considering construction sequence. The unexpected heaving which can bring up a dangerous situation for train running stability were measured, so this study shows that the upward movement has to be analyzed in designing process. As the use of underground space increases, the proposed method can be a good example of underground development.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1396-1403
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• 2009

The Ministry of Construction and Transportation (MOCT) has been constructing a nationwide soil information DB since 2000, as basic data for the construction of 'underground geographical information,' a project under the 2nd National Geo-spatial Information System (NGIS) master plan. The inputted soil information includes not only underground conditions such as the layer depth, type, color, and groundwater level, but also engineering information that can be applied to construction work design, such as on the standard penetration test and the compression test. It is difficult to use this information in soil analysis and design, however, because only the test results are currently available. A web-based geo-spatial information system was developed in this study to facilitate the effective application of the soil information database (DB). First, the space information, layer information, and engineering test information were loaded from the soil information DB in real time, and the earth volume, bearing capacity, and settlement were calculated to develop a web client that will evaluate the ground softness and liquefaction. It seems that the soil information DB can be actively applied to the planning and design of construction works using this system.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.41-42
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• 2017

In this study, an investigation was made to study the chemical resistance performance of epoxy resin injection type leakage repair material used in the Korean construction market in accordance to the test method outlined in "ISO TS 16774, Part 2; Test Method for Chemical Resistance." This is a new standard document used for quality control method of injection type repair material used for leakage cracking of underground concrete structures. The results of this study can be expected to be utilized as reference data that can be used for quality improvement of the maintenance methods for future construction.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.220-221
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• 2019

At a time when the recent earthquake in Pohang, Korea requires the need for seismic performance design not only for concrete structures but also for construction materials used in construction structures, the possibility of applying the seismic performance design of waterproof materials constructed in the form of direct or partial adhesion to concrete structures in the underground Single-side walls section was confirmed.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.87-91
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• 2015

For construction projects it is imperative that site management gives the highest priority to planning safe site evacuation for all foreseeable emergencies, including earthquakes and typhoons which are often experienced in Japan. This is especially important and even more critical for high risk projects involving underground works, such as Tunneling & Pneumatic Caissons. Based on the safety regulation of underground works, a back-up power supply system must be provided during the construction period at all times. Often, fluorescent lamps with re-chargeable batteries are provided for infrequent emergency cases, however these have a questionable useable life span and thus need careful maintenance and periodical replacement. In this paper we focused on using the phosphorescence materials to indicate the evacuation direction. As a result, it was confirmed that the phosphorescence materials were considered useful in reducing panic and facilitating a controlled evacuation in the event of a total black-out due to power failure.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.233-234
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• 2019

Research has begun to change the waterproofing design of domestic underground structure parts from the current negative-side waterproof design to the positive-side waterproof design. For this, active review from the design stage to prevent the ingress of external ground water into the waterproofing measures of the underground of apartment buildings is needed. Therefore, in this study, proper waterproofing method for the major leaks identified in the previous studies and a waterproofing method for the waterproof design of the underground floor and the outer wall is proposed. It is hoped that a follow-up study, such as a review of field applicability, for the proposed methods will provide an alternative to secure leakage stability in waterproof design.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.235-236
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• 2022

Electric vehicle fires in underground parking lots are very dangerous, but it is judged that the current related laws and regulations do not change, which will cause problems. As a result of the analysis for the purpose of providing an electric vehicle in an underground parking lot, fire-resistance coating is essential as it can cause an explosion in the building members made of high-strength concrete when an electric vehicle fire occurs in an underground parking lot. Since a fire occurs, it is necessary to prevent electric vehicles from parking adjacent to each other.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.3
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• pp.239-255
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• 2007

An underground research tunnel is essential to validate the integrity of a high-level waste disposal system, and the safety of geological disposal. In this study, KAERI underground research tunnel(KURT) was constructed in the site of Korea Atomic Energy Research Institute(KAERI). The results of the site investigation and the design of underground tunnel were presented. The procedure for the construction permits and the construction of KURT were described briefly. The in-situ experiments being carried out at KURT were also introduced.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.754-761
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• 2008

In general, stress measurement of existent shotcrete lining be used by pressure cells. but, measuring instrument is lost by high pressure at shotcrete lining construction and pressure cell's measurement value have to low believability by natural conditions like curing temperature. In this study, proposed techniques to measure without utilizing sensitive stress sensor in natural condition at point that want stress of shotcrete lining after shotcrete lining construction. Executed numerical analysis to forecast stress level that interact in tunnel shotcrete lining, measured strain of hole by load action through hole in shotcrete lining. 3D FEM(finite element method) is enforced through various parameters curing time of shotcrete lining, thickness, load condition. Different model cases applied by parametic study. As analysis result, it could grasp development possibility of method that propose this time because it could examine corelation with strain by near hole of shotcrete lining and stress about load condition.

• Geomechanics and Engineering
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• v.18 no.5
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• pp.527-534
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• 2019

Although ground investigation had carried out prior to the construction, many problems have arisen during the civil-engineering works because of the presence of the unexpected underground utility lines or anomalies. In this study, a new geophysical exploration method was developed to solve those problems by improving and supplementing the existing methods. This new method was based on the difference of electrical resistance values between anomalies and surrounding ground medium. A theoretical expression was suggested to define the characteristics of the anomalies such as location, size and direction, by applying the electric field analysis. An inverse analysis algorithm was also developed to solve the theoretical expression using the measured electrical resistance values which were generated by the voltage flowing the subsurface medium. To verify the developed method, field applications were conducted at the sites under construction or planned. From the results of the field tests, it was found that not only the new method was more predictive than the existing methods, but its results were good agreed with the measured ones. Therefore, it is expected that application of the new exploration method reduces the unexpected accidents caused by the underground uncertainties during the underground construction works.