• Journal of the Korean Geotechnical Society
• /
• v.34 no.7
• /
• pp.17-27
• /
• 2018

Sinkholes have occurred in various places around the world and concerns about public safety have been raised in recent years. Particularly, a ground subsidence may occur due to a variety of conditions when developing underground spaces. Ground subsidence refers to the sinking of the Earth's surface caused by the loss of the soil constituting ground due to a certain artificial cause in the ground. Ground subsidence is induced by artificial causes such as the leakage of water supply/sewage pipes and groundwater disturbance, and it is different from a sinkhole, where the sinking of the Earth's surface is induced by the cavity formed due to the melting of limestone in the ground with limestone bedrock. In recent underground development in the urban areas of Korea, damages to surrounding buildings have frequently led to many difficulties with civil complaints and compensation issues, and the collapse of some buildings has resulted in the loss of lives and property. Accordingly, the central government has legislated the Special Act on Underground Safety Management, which will take effect from January 1, 2018. This law specifies an underground safety management system for securing underground safety, under which underground safety impact assessment is performed for projects involving underground excavation work that exceeds a certain size, and safety inspection is regularly performed for underground facilities and the surrounding ground. In this study, the contents of the special act on underground safety management are reviewed, and the direction of development of underground safety policy for preparing preemptive underground safety management preparation and response system is suggested.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.40 no.5
• /
• pp.413-419
• /
• 2022

As the development of the underground space becomes active, safety accidents related to the underground are frequently occurring in recent years. In this regard, the Ministry of Land, Infrastructure and Transport is enforcing the 『Special Act on Underground Safety Management』 (enforced on January 1, 2018, hereafter referred to as the Underground Safety Act). Among the core contents of the Underground Safety Act, underground facilities(water supply, sewage, gas, power, communication, heating) buried underground, underground structures(subway, underpass, underpass, underground parking lot, underground shopping mall, common area), ground (Drilling, wells, geology) of 15 types of underground information can be checked at a glance on a three-dimensional basis by constructing an integrated underground spatial map and using it. The purpose of this study is to develop a program that can quickly inspect the three-dimensional model after creating a three-dimensional underground structure data among the underground spatial integration maps. To this end, we first investigated and reviewed the domestic and foreign status of technology that generates and automatically inspects 3D underground structure data. A quality inspection program was developed. Through this study, it is judged that it will be meaningful as a basic research for improving the quality of underground structures on the integrated map of underground space by automating more than 98% of the 3D model inspection process, which is currently being conducted manually.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.21 no.1
• /
• pp.23-34
• /
• 2018

Recently, mainly in downtown, there have been frequent safety incidents in underground space like ground subsidence and land sinking. Out of diverse coping measures, the government is carrying forward the establishment of underground space integrated map. As a core element of the underground space integrated map, the 3D geotechnical information is used as major data of underground space impact assessment obliged in accordance with the "Special Act on the Safety Control of Underground Space Safety". The construction method of 3D geotechnical information is drawn when establishing the basic establishment plan of underground space integrated map, and the continuous construction is performed by the Integrated DB Center of National Geotechnical Information. However, it is necessary to draw concrete measures with accuracy, efficiency, and utilization. This study drew the construction plan considering the accuracy, utilization, and efficiency of 3D geotechnical information for the support of underground space safety. For this, accuracy between elevation and underground level is compared using MVS and MakeJiban which are software to construct boring information with geotechnical information in geotechnical information portal system. In the results of general analysis, the milepost-based construction of whole strata in a lump would be the most suitable in the aspect of accuracy, utilization, and efficiency. Based on the results of this study, Plan to construct 3D geotechnical information will be pursued.

• Journal of the Korean Society of Safety
• /
• v.37 no.6
• /
• pp.50-59
• /
• 2022

In the Construction Technology Promotion Act (CTPA) of the Republic of Korea, safety management cost is enforced as a statutory cost that must be included in the budget of construction projects. However, the construction of underground electric power transmission facilities (UEPTFs) is not included in the category of construction works defined in the CTPA. Consequently, the statutory safety management cost does not apply to the construction of UEPTFs. To overcome this limitation, the clients of UEPTF construction projects generally provide internal guidelines enabling the addition of the safety management cost in the project budget. Nevertheless, even after the execution of the internal guidelines, some important cost items are omitted from the budget owing to the incompleteness of the guidelines. In this context, this paper proposes a complete set of accounting items and their calculation methods for appropriate budgeting of the safety management cost of UEPTF construction projects. To this end, the current budgeting method of the safety management cost of UEPTF construction projects is analyzed, and a questionnaire study is performed to confirm the necessary cost items and their appropriate calculation methods. Based on the results of the questionnaire study, a set of accounting items and their calculation criteria for the budgeting of the safety management cost of UEPTF construction projects are proposed.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.24 no.3
• /
• pp.32-40
• /
• 2021

Underground information is difficult to visually check, which can lead to a huge accident in the event of a safety accident. Recently, the Ministry of Land, Infrastructure and Transport intends to reduce safety accidents caused by the aging or damage of underground facilities through the Special Act on Underground Safety Management. GPR is increasingly being used as a technology to acquire information in underground spaces that are difficult to see with the naked eye. However, GPR's location information is corrected by checking images of CCTV and GPS information acquired during exploration. This method has an average error of about 2 meters. In this works, We used LiDAR to calibrate the GPR information and found that the error was reduced from at least 7cm to up to 40cm. If accurate GPR information collected in the future is analyzed quickly using AI, etc., it will be able to collect and utilize underground information faster than it is now to secure safety.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.26 no.4
• /
• pp.17-26
• /
• 2023

The integrated underground space map is a three-dimensional map that integrates 16 types, including 7 types of underground facilities, 6 types of underground structures, and 3 types of ground. In order to systematically construct, manage, and utilize the integrated underground space map, it was institutionalized as the "Special Act on Underground Safety Management," and the "Underground Space Integrated Map Production Work Regulations" was prepared as detailed work regulations. However, there is a lack of institutional mechanisms to develop new technologies such as the completed book submission system for submitting change information and automation technology for updating the integrated underground spatial map and to expand the usability of the integrated underground spatial map. Accordingly, this study examined the current status of the integrated underground space map and attempted to suggest a direction for improving the current system through a revision plan and detailed operation management regulations (draft) of the Special Act on Underground Safety Management.

• Journal of the Korean Geotechnical Society
• /
• v.37 no.1
• /
• pp.29-41
• /
• 2021

Although underground works are essential to use underground spaces in urban areas efficiently, various damages caused by constructions have often occurred, making them major social problems. Since 2018, it is stipulated in the Special Act on Underground Safety Management that appropriate construction methods must be used in the design stage to prevent various damage cases. This Special Act includes establishing an area subject to underground safety impact assessment, analysis of ground and geological status, review of effects caused by changes in groundwater, review of ground safety, and establishment of measures to secure underground safety. This study area consists of various strata in order of landfill, sedimentary silt, sedimentary sand, sedimentary gravel, weathering zone, and foundation rock. Also, the slurry wall, a highly rigid underground continuous wall, was chosen as a construction method to consider high water table distribution and minimize the influence of the surroundings in this area. However, ground subsidence occurred on the road nearby in December 2019 due to the inflow of loosening soil to the construction area. Thus, several types of site investigations were conducted to suggest an appropriate analysis method and to find out loosed ground behavior and its area for the subsided site. As a result, new design soil properties were re-calculated, and the reinforcement measures were proposed through analytical verification.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.26 no.4
• /
• pp.56-66
• /
• 2023

Safety accidents are increasing, such as changes in groundwater levels due to construction work or natural influences, or ground cave-ins caused by soil runoff from old water supply and sewage pipes. In addition, underground facility management agencies must make efforts to improve the accuracy of underground information through continuous investigation and exploration in accordance with the Special Act on Enhanced Underground Safety Management. Accordingly, in this study, we defined the configuration of equipment and data processing method to collect 3D precise exploration underground facility information and developed 3D underground facility information collection technology to ensure accuracy of underground facilities. As a result of verifying the developed technology, the horizontal accuracy improved by an average of 6cm compared to the existing method, making it possible to acquire 3D underground facility information within the error range of the public survey work regulations.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.39 no.6
• /
• pp.469-476
• /
• 2021

The framework plan for the development of an integrated underground space map was established of preventing ground subsidence. The mapping process is expected to be completed to the level of nationwide municipal government standards by end of this year. To facilitate the utilization of the integrated underground space map, paper-based drawings for specialized organizations in underground safety impact assessment have been provided since September 2018, and services for local government officials have been provided in the underground information utilization system since May 2019. However, the map is utilized based on the information at the time of the initial development of the map, without any updates, thereby resulting in a lack of accuracy and latest information. This has led to a decrease in the utilization and reliability of the information. Therefore, in this study, for the underground structures(subway, underground shopping mall, underground passage, underground roadway, underground parking lot, utility tunnel), which are the key components of the integrated underground space map, a standard format for the submission of completed drawings is designed in accordance with Article 42 (2) of the Special Act on Underground Safety Management, which aims at laying the foundation for establishing the updated system of the integrated underground space map. In addition, through the verification of the automatically updated underground structure data based on the standard format, the reliability of the data can be assured. This format is expected to contribute to the improved utilization of the integrated underground space map in the future.

• Tunnel and Underground Space
• /
• v.28 no.4
• /
• pp.293-303
• /
• 2018

Monitoring is the act of collecting and analyzing accurate engineering information using various methods and instruments. The purposes of the monitoring are design verification, construction management, quality control, safety management, and diagnose of structure etc.. The diagnose evaluation of the geotechnical structures corresponds to the confirmation of the structural performance. It is aimed to judge the soundness of geotechnical structures considering the degree of damage due to the environmental change and elapsed time. Recently, microseismicity, which is widely known in Korea, can be used for safety management and diagnoses of structure as it detects the micro-damage without disturbance of the structure. This report provides guideline on the procedure for assessing an underground oil storage cavern using microseismic monitoring techniques. Guidelines cover the selection of monitoring systems, sensor array, sensor installation and operation of systems, and interpretation.