• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.5
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• pp.607-617
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• 2009

With the promotion of the u-City project in recent years, the need for the systematic and efficient management of ground and underground facilities comprising the urban infrastructure has been increased. Considering that the diverse services provided in the u-City are closely related to the physical environment of the city itself, including its location and condition, the core of such management must be to continuously maintain these facilities in a normal state, based on accurate data collection from the facilities. This paper discusses a method of collecting the sensor and the object data that are needed to accurately understand the state of the underground facilities, and presents a plan to build an Underground Facility Management System on this basis. This plan is then verified using a scenario test performed by a prototype system.

• The Korean Journal of Air & Space Law and Policy
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• v.21 no.1
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• pp.7-27
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• 2006

When cadastre system was first introduced in Korea, we only uses the surface of the land and thus its form was very simple. Nowadays on account of the development of architectural technology, the rapid expansion of population and urbanization, the cubic utilization of land including the land usage of underground and surface space is widely settled. This article studies the function of cadastre and public notice to encourage cubic utilization of the land, argues the necessity of 3D-cadastre system to protect property right, and suggests the GPS land measurement as a possible measure.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.2
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• pp.109-118
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• 2022

GPR (Ground Penetrating Radar), developed as a technology for geotechnical investigations such as sinkhole exploration, was used limitedly as a method to resolve undetectable lines in underground facility exploration. To improve the accuracy of underground facility data, the government made it possible to explore underground facilities using a non-metallic pipeline probe from July 2022. However, GPR has a problem in that the exploration rate is lowered in the soil with high moisture content, such as soft soil, such as clay layer, and there is a lot of variation in long-term accuracy. In this study, as a way to improve the accuracy of exploration considering the characteristics of GPR and the environment of underground facilities, we propose a GPR exploration method for underground facilities using permittivity constant correction and pattern analysis of GPR image data. Through this study, the accuracy of underground facility exploration and high reproducibility were derived as a result of field verification applying GPR frequency band and heterogeneous GPR.

• Spatial Information Research
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• v.18 no.4
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• pp.23-32
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• 2010

Water mains underground facilities are essential components to make up urban infrastructure. In order to manage these water mains underground facilities systematically and scientifically, GIS (Geographic Information System) had been constructed. For the sake of construction of GIS for water mains underground facilities, an exact underground detection and the construction of DB (Data Base) for buried water mains underground facilities should be preceded. In this study, in order to find out the ways to improve exact detection rate of data, the statistical analysis for the causes of detection raw degradation was done, and standardization methods of detection through a case study were suggested, When water mains underground facilities were measured, the detection of non-metallic water pipes was not carried out. The reason was that the results of detection was uncertain and detection was difficult because the assessment of public measurements was vulnerable. Moreover, due to the absence of standardized operating regulations for detection, systematic surveys weren't conducted. In this study, methods to standardize works over the detection of water mains underground facilities were presented so that we can improve the detection rate when we are doing that. As the proposals to improve detection rate, effective performance assessment over non-metallic pipes were presented, and related issues to supplement work regulations of public survey were described systematically.

• Explosives and Blasting
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• v.39 no.4
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• pp.22-33
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• 2021

Recently, the frequent occurrence of ground subsidence in urban areas has caused increasing anxiety in residents and incurred significant social costs. Among the causes of ground subsidence, the rupture of old water and sewer pipes not only halts the operation of the buried pipes, but also leads to ground and water pollution problems. However, because most pipes are buried after construction and cannot be seen with the naked eye, the importance of maintenance has underestimated compared to other structures. In recent years, integrated physical exploration has been applied to the maintenance of underground pipes and structures. Currently, to investigate the internal conditions and vulnerable portions of the ground, consolidated physical surveys are executed. Consolidated physical surveys are analysis techniques that obtain various material data and add existing data using multiple physical surveys. Generally, in geotechnical engineering, consolidated physical surveys including electrical and surface wave surveys are adopted. However, it is difficult to investigate time-based changes in under ground using these surveys. In contrast, surveys using cosmic-ray muons have been used to scan the inner parts of nuclear reactors with penetration technology. Surveys using muons enable real-time observation without the influence of vibration or electricity. Such surveys have great potential for available technology because of their ability to investigate density distributions without requiring as much labor. In this paper, survey technologies using cosmic ray muons are introduced, and the possibilities of applying such technologies as new physical survey technologies for underground structures are suggested.

• Tunnel and Underground Space
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• v.19 no.6
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• pp.517-525
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• 2009

Stereophotogrammetry is used to extract spatial information of an interested object by constructing a stereo-image from two or more photos. In this study, the stereophotogrammetry was adopted for a rock joint survey in mine tunnels. The orientations of discontinuities were measured from two mine tunnels with a clinocompass. To evaluate the effect of photographing light level on the stereophotogrammetry analysis, the light intensity was changed within a predefined range for every photograph. Those photographs were analyzed by using a commercial code for stereophotogrammetry - ShapeMetriX 3D, and the results from the analysis were compared with the manual measurement using a clinocompass.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.231-235
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• 2007

As the centralization of city, underground facilities is increasing and being more important. And there were many underground facilities accidents in korea. It is very important to update and to have high quality accuracy of underground facilities maps. But the underground facilities maps are mapped and updated by each institutes. So it is difficult to verify the accuracy of the data. In this study, To analyze the accuracy of maps, Surveying of undergroud facilities for 18 GUs in Seoul is performed during 3 years using Electromegnetic Induction Method, Total Station and GPS. In conclusion, Horizontal accuracy of 6 underground facilities management institutes is 73cm(2004), 78cm(2005) and 75cm(2006).

• Tunnel and Underground Space
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• v.13 no.3
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• pp.207-214
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• 2003

To obtain Digital Elevation Model(DEM) from an exposed rock mass, techniques such as laser scanning and digital stereo photogrammetric technique are recently applied. We have obtained the DEM of the rock slope using above techniques in this study, and examined a suitability and improvement of the photogrammetry for the rock slope by overlapping the DEM. This study can be applied to the measurement of fracture orientations, the prediction of rock joint network, and the analysis on the change of the rock slope.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.287-290
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• 2003

The base composition for a construction information union and application is insufficient, because the existent information driving for the underground facility is separately promoted from management organization. This Study is to analyze a accuracy by converting pre-constructive underground facility database to the unification database of digital map base and improve the accuracy for a field surveying. moreover, These results is to construct the information common system of web base GIS by jointing internet technology.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.167-171
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• 2004

최근 들어 위성영상은 자료 처리 방식에 따라 지구표면이나 또는 지하면에 대한 다양한 정보(물리적인 정보, 화학적인 정보)를 얻을 수 있고 실제 지구를 가상으로 구현하는 데 활용될 수 있기 때문에 여러 산업에서 활용하고 있다. 또한 분류는 영상에 포함된 여러 가지 대상물을 구별하기 위해서 화소와 비교적 성질이 같은 화소 그룹별 특징에 대응되는 레벨을 지정하는 기술이 요구되며, 최소거리 분류법, 평행사변형법, 마하나로비스거리법(Mahanalobis Distance Method), 최대우도법(Maximum Likelihood Method)등 비교하여 분류를 수행