• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.5
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• pp.621-640
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• 2019

Quantitative stability assessment of underground cavities can be presented as a factor of safety based on the Shear Strength Reduction Method (SSRM). Also, SSRM is one of the stability evaluation methods commonly used in slope stability analysis. However, there is a lack of research that considers the relationship between the probability of occurrence of cavities in the ground and the potential failure surface of the slope at the same time. In this study, the effect of small underground cavities on the failure behavior of the slope was analyzed by using SSRM. Considering some of the glaciology studies, there is a case that suggests that there is a cavity effect inside the glacier in the condition that the glacier slides. In this study, the stability evaluation of underground cavities and slope stability analysis, where SSRM is used in geotechnical engineering field, was carried out considering simultaneous conditions. The slope stability analysis according to the shape and position change of underground cavities which are likely to occur in the lower part of a mountain road was analyzed by using SSRM in FLAC3D software and the influence of underground cavities on the slope factor of safety was confirmed. If there are underground cavities near slope potential failure surface, it will affect the calculation of a factor of safety. The results of this study are expected to be basic data on slope stability analysis with small underground cavities.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.454-455
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• 2006

This paper describes the safety assessment algorithm applied for the underground electrical utilities submerged due to flooding. In implementing the algorithm, several factors pertaining to utility safety were introduced into the process flow, and safety weight was given to each factor. It is considered that this algorithm can ensure the safety of electrical utilities installed underground when they are submerged.

• Magazine of korean Tunnelling and Underground Space Association
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• v.13 no.3
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• pp.60-63
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• 2011

• Magazine of korean Tunnelling and Underground Space Association
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• v.23 no.2
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• pp.63-78
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• 2021

• Geomechanics and Engineering
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• v.22 no.1
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• pp.25-33
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• 2020

In metropolitan areas, the quantity and density of the underground structure increase rapidly in recent years. Even though most damage incidents of the underground structure were minor, there were still few incidents causing a great loss in lives and economy. Therefore, the safety evaluation of the underground structure becomes an important issue in the disaster prevention plan. Liquefaction induced uplift is one important factor damaging the underground structure. In order to perform a preliminary evaluation on the safety of the underground structure, simplified prediction equations were introduced to provide a first order estimation of the liquefaction induced uplift. From previous studies, the input motion is a major factor affecting the magnitude of the uplift. However, effects of the input motion were not studied and included in these equations in an appropriate and rational manner. In this article, a numerical simulation approach (FLAC program with UBCSAND model) is adopted to study effects of the input motion on the uplift. Numerical results show that the uplift and the Arias Intensity (Ia) are closely related. A simple modification procedure to include the input motion effects in the Sasaki and Tamura prediction equation is proposed in this article for engineering practices.

• Journal of the Korea Institute of Building Construction
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• v.20 no.3
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• pp.253-260
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• 2020

With increasing interest in an underground-type ammunition storage facility, several design results have been provided recently. However, since not only experts in the tunnel but also military persons in charge of ammunition have not fully understood the safety distance standard, reliable design results are not being produced. In this study, the effective design method of an underground-type ammunition storage facility was provided by analyzing the current safety distance standard. First, the critical safety distances that dominate the size of construction site for underground-type ammunition storage facilities were evaluated, which are the layout of chambers and the configuration of the entrances. Then, the decreasing effect of inter-chamber distance was studied according to the rock type and the storage density of ammunition. In addition, the method of designing tunnels with parallel lines and two-floors was considered for arranging more chambers while complying with the safety distance standards. In particular, numerical simulations were carried out to determine the satisfaction of the safety distance standards when an underground-type ammunition storage facility is composed of two-floor and the decreasing effect of inter-chamber distance according to the inner explosive pressure reduction. Finally, the method to adjust the size of entrances and the path of pressure were studied for decreasing the safety distance at the entrance.

• Journal of the Korean Institute of Gas
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• v.13 no.2
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• pp.36-40
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• 2009

In this study, we surveyed 544 drivers, who had taken the education course for autogas car drivers, to figure out their safety awareness status including the recognition of hazards of gas leaking from autogas cars and response attitude toward them. As a result of the survey, we found out that 63% of the responders recognized the hazards of gas leakage and 79% preferred parking in the aboveground areas. For the necessity of introducing restrictions on autogas cars parking in underground lots, 58% of all responders answered yes while 71% of the responders aged over fifties and 73% of them who responded to have known the hazards of parking in underground answered in the affirmative. Furthermore, we found out that responders who had recognized the hazards preferred aboveground parking areas, and the responders who had preferred the aboveground recognized the hazards of parking autogas cars underground and felt the necessity of restricting them from parking in underground relatively high. Through the analysis of these results, we can analyse that the drivers who are aware of the hazards of gas leakage have higher safety attitude for hazards than the other drivers who are not aware of them.

• Proceedings of the Korean Geotechical Society Conference
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• 1993.10b
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• pp.133-162
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• 1993

The environment of underground spaces might be considered in view of working environment during the construction and living environment after completion of the construction work. For controlling environment of underground space, an appropriate measures have to be taken on the governing factors such as air flow, dust, gases, heat, radiation, noise, illumination and water. The more critical matter, in underground environmental point of view, is underground disasters such as fire, gas explosion and water inrush. This paper presents the general introduction of these factors mentioned above and some outcomes of research works as of now.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.3
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• pp.167-177
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• 2021

Facilities located in the underground space are closely related to the sanitation and safety of the city, and the underground spatial information is precisely constructed and used as important information for facility maintenance, safety, and underground space development. In this study, a method was studied to increase the field usability by increasing the reliability of underground spatial information constructed in Korea and used in the field. For this study, the current status of the construction of underground spatial information in Korea was summarized, and cases of the underground spatial information quality grading system applied in the US, UK, Canada, France, and Australia, which are advanced geospatial information countries, were investigated. In terms of field usability, a questionnaire was conducted on the systems, standards, and management methods related to underground spatial information of field experts and consumers working in related fields in Korea, and statistical analysis was conducted to analyze the relevance of the introduction. Through this study, it was concluded that it is necessary to introduce a quality grading system according to the construction method of underground spatial information, accuracy and reliability, and to improve related systems and regulations.

• 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.