• Title/Summary/Keyword: Underground

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A Study on the Detecting Method for Underground Pipes Using Magnetic Field (자기장을 이용한 매설배관의 위치탐지에 관한 연구)

  • Bae, Bong-Kook;Yang, Yean-Soon;Song, Chun-Ho;Seok, Chang-Sung
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.32-37
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    • 2001
  • As increasing underground facilities, more effective management is needed nowadays. It is important to get an accurate information of underground facilities to manage that, so some methods of detecting location - electromagnetic induction method, ground penetration radar method, sonic method - are used to obtain the information of underground facilities. In this study, a magnetic method to detect underground facilities was developed. In the magnetic method, underground facilities are detected by a detector and the magnetic marker which is a permanent magnet and used to marking the location by attaching underground facilities. A proper characteristic of the magnetic marker was optimized by maxwell 20 magnetic field analysis tool, a test field was constructed with the magnetic marker, PVC pipe, and steel pipe under ground 1.5m, and the detector was made by modifying a common ferromagnetic detector. Magnetic strengths of the magnetic marker were measured by the detector at each location in the test field, and analyzed by magnetic field analysis tool in the same condition. In the result, the underground pipes were detectable within the deviation ${\pm}20cm$ at PVC pipe and ${\pm}10cm$ at steel pipe respectively. The steel pipe was more detectable by ferromagnetism. The developed magnetic method can be applied to maintain and manage underground facilities.

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An Analytical Study on the Patents Substance of Urban Underground Space Development Technology (도시지하공간 개발기술에 대한 특허동향 분석)

  • Lee, Gahng-Ju
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.6
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    • pp.129-137
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    • 2019
  • The purpose of this study is to present systematic information and direction to urban underground space development industry, civil engineering and R&D. Regarding the development of urban underground space, the situation in Korea, especially now in Seoul, can be called an underground Renaissance. The Superground project, which has been going on for several years through international competition, is now completed and is about to open the Seoul Architecture Museum. Leading underground space complex development project of Yeongdongdaero, which is the largest living underground space in human history, spectral projects such as the Seoul section of the GTX routes, making underground roads of the Dongbu Expressway and the Seobu Expressway are now speeding up progress. Recently, plans have been made to use the underground more actively through the restructuring project of Gwanghwamun Square, the face of Seoul. And then, patents are indispensable resources for establishing a strategy for R&D as one of the indices showing what technologies have been developed and what technology development will be done in the future. Based on this background, this study attempts to classify and define the technical elements of urban underground space development through the analysis of patents of major countries in the world, and analyze and present state of technology level and situation accordingly.

Relationship between Flood Characteristics and Underground Inundation (홍수특성과 지하공간침수의 관계 검토)

  • Lee, Dae-Young;Lee, Keon-Haeng;Kyoung, Min-Soo;Kim, Hung-Soo
    • 한국방재학회:학술대회논문집
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    • 2007.02a
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    • pp.367-370
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    • 2007
  • In recent, the utilization of underground in urban area is increased as subway, store, and others but we have done a few studies for the inundation of underground due to flooding. So, we investigate the examples of underground inundation and the causes of inundation for flood events. And the relationship between flood characteristics and underground inundation is analyzed through the frequency of rainfall which is made by annual multi maximum series. As a result, most of underground is inundated by high frequency of rainfall. And there are some cases that the underground is inundated by low frequency of rainfall because of poor drainage system and characteristics of location.

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Indoor and Outdoor Formaldehyde Concentrations in Underground Environments (실내외 포름안데히드 농도에 관한 조사연구)

  • 김윤신;김미경
    • Journal of Environmental Health Sciences
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    • v.15 no.2
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    • pp.1-9
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    • 1989
  • A pilot study was conducted in order to measure indoor and outdoor formaldehyde levels during August 3 - 22, 1988 in several underground spaces in Seoul. Formaldehyde concentrations were monitored during 1 week in selected sampling areas (subway station, underground shopping center, underpass, tunnel, underground parking lot) using passive formaldehyde monitors. In order to investigate a relationship between respiratory prevalence and levels of formaldehyde, each subject was asked to answer respiratory questions. The mean formaldehyde concentrations were 60.1 ppb in subway station, 122.2 ppb in underground shopping stores, 72.1 ppb in underpasses, 39.7 ppb in tunnel, and 75.9 ppb in underground parking lots, respectively. The mean indoor formaldehyde concentrations in underground environments varied from 28.6 ppb to 118.7 ppb. Generally, the mean formaldehyde concentrations in ticketing office in subway stations appeared higher than those level measured in platform. The mean formaldehyde concentrations of underground shopping center in Gangnam Terminal were higher than any other areas and it exceeded 100 ppb of the American Ambient Air Quality Standards of formaldehyde. Prevalence rates of respiratory symptoms of dwellers seemed to be related to higher indoor formaldehyde levels.

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Urban Uses of Underground Space around the World

  • Nelson, Suasn R.
    • Tunnel and Underground Space
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    • v.2 no.1
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    • pp.1-10
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    • 1992
  • As our global population grows each day, it is apparent that we must find new ways to provide space for habitation and the services necessary to support large urban areas. It is no longer advisable nor acceptable to continue to expand our cities on the surface, encroaching on valuable agricultural land and open space. We must also find ways to be more energy efficient in every aspect of our societies. Effective use of underground space can provide the space necessary to accommodate larger populations and the services necessary for their support in existing urban areas we can also find new ways to utilize underground facilities to improve urban efficiency and function. Underground technology has improved dramatically in the last two decades and continues to evolve to meet a great variety of applications. The confluence of available technology, economic feasibility, and greater acceptance of underground solutions with recognition of the need to change the ways we build and use out urban areas and their surrounding environment indicates that we are witnessing only the beginning of appropriate and innovative use of underground space future generations will indeed 'Think deep'.

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A Study on the Comparison of Measurement and Prediction of Underground Temperature in Gumi. (구미지역 지중온도의 실측과 예측에 관한 비교 연구)

  • Jeong sooill
    • Journal of the Korean housing association
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    • v.15 no.4
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    • pp.99-105
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    • 2004
  • Korea gets most of its housing energy from fossil fuel which can be mined only for 30 years. So the development of an alternative energy is very important. Solar and underground thermal energy are two of these alternatives but little study has been conducted on these. For use of underground energy, we need accurate data regarding underground temperature, but there are only 30 measuring points for underground temperature in the entire country. We need to have a method of predicting underground temperature precisely. In this study the underground temperature is measured at under 3m in Gumi, and these data are compared with predicted data for checking the accuracy of the predicting method.

Effect of the Capacitance for 600V CV Cable Applying Outdoor Electricity Facilities (옥외전기시설물에 사용되는 600V CV케이블 정전용량의 영향)

  • Lee, H.G.;Ha, T.H.;Bae, J.H.;Him, D.K.;Kim, S.W.;Lee, J.I.
    • Proceedings of the KIEE Conference
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    • 2002.11b
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    • pp.323-325
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    • 2002
  • Because of the progress of civilization, outdoor electricity facilities as a street light, signal light and standing signboard etc. have being increased rapidly. Therefore the application of underground distributing wires is largely expended. In this paper, capacitance for the kinds of 600V CV cable is measured and leakage current for underground cable is calculated. The measurement of capacitance is done which there are defects of cable sheath or not Calculated leakage current is applied to choose the circuit breaker and the like.

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Numerical Analysis of the Effect of Ground Source Heat Pump Systems on the Underground Temperature (지열 시스템의 도입이 지중온도환경에 미치는 영향에 대한 해석적 검토)

  • Nam, Yujin
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.25 no.8
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    • pp.427-431
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    • 2013
  • Ground heat pump systems utilize the annually stable underground temperature to supply heat for space heating and cooling. The underground temperature affects not only the underground ecosystem, but also the performance of these systems. However, in spite of the widespread use of these systems, there have been few researches on the effect of the systems on underground temperature. In this research, case studies with numerical simulation have been conducted, in order to estimate the effect of ground heat pump systems on underground temperature. The simulation was coupled with the ground water-ground heat transfer model and the ground surface heat transfer model. In the result, it was found that the underground change depends on the heat transfer from the ground surface, the heat exchange rate, and the heat conductivity of soil.

From Fragmented Development to Three-Dimensional and Coordinated Development - Research on Renewal Strategies of Existing Underground Commercial Space in Harbin

  • Xue, Minghui;Su, Yiming;Hu, Jiayu
    • International Journal of High-Rise Buildings
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    • v.10 no.1
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    • pp.17-28
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    • 2021
  • In Harbin, a network of underground commercial spaces has been developed to occupy spaces that were originally created as civil defense shelters. With the gradual extension of the local metro rail system, the existing underground commercial space is no longer an isolated regional development, but a space that represents "three-dimensional city" and coordinated development taking place in many Chinese cities. Based on the analysis of the unique development process taken in underground space of Harbin, this paper summarizes three characteristics of its early model of "fragmented development" of underground space. By conducting a comprehensive field research and survey, the researchers analyzed 472 questionnaires related to the development trend, and proposed multi-level synergistic elements for the renewal and development of underground commercial space. The paper concludes by discussing the trend of "three-dimensional and collaborative development," suitable for the development needs of the new era, and the corresponding development strategies for the renewal of underground space.

A numerical study on the characteristics of small underground cavities in the surrounding old water supply and sewer pipeline (노후 상하수관 주변지반의 소규모 지하공동 형상 특성을 고려한 수치해석에 관한 연구)

  • An, Joon-Sang;Kang, Kyung-Nam;Song, Ki-Il;Kim, Byung-Chan
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.20 no.2
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    • pp.287-303
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    • 2018
  • In recent years, the occurrence of ground subsidence phenomenon is frequent in Korea. The Korean government has enacted a special law on underground safety and the law will be enforced from January 1, 2018. Under this new law, underground excavation should be assessed for underground safety impacts. After excavation construction, periodic geophysical surveys should be conducted to investigate the occurrence of underground cavities. When underground cavities were discovered, the underground safety was assessed through numerical analysis. However, it is controversial because the method of numerical modeling the discovered underground cavity is due to be established. In this study, the effect of the depth of the underground cavity from the shape of the underground cavity to the underground cavity was studied using a continuum analysis program. In this study, a method to reflect the shape of the underground cavity to the numerical modeling is presented. The relationship between the shape and depth of the underground cavity, and the factor of safety calculated by the shear strength reduction method (SSR) is presented. The results of this study are expected to form the basic data on underground safety impact assessment.