• Title, Summary, Keyword: Ground investigation

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A Study on the Improvement of Electrode Installation for Measurement of Ground Resistance through Investigation on the Spot in Buildings (현장조사를 통한 건축물 접지저항 측정용 전극 설치의 개선에 관한 연구)

  • Gil, Hyoung-Jun;Kim, Dong-Woo;Kil, Gyung-Suk
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.5
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    • pp.92-97
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    • 2011
  • This paper deals with the improvement of electrode installation for measurement of ground resistance through investigation on the spot in buildings. The investigation was carried out for an earthing terminal board for measurement of ground resistance, installation of auxiliary electrode, etc. The criteria value is set up by measuring method of ground resistance in international standard. In case of inadequate installation of auxiliary electrode, a relative error is analyzed and adequate installation method of auxiliary electrode is proposed. As a consequence, it is necessary to write direction of ground and equipment, and separate auxiliary electrode for measurement of ground resistance in order to minimize measuring error.

A Study on Risk Influence Factors of Ground Subsidence through Soil Investigation Analysis (지반조사 분석을 통한 지반함몰 위험영향인자 연구)

  • Joung, Ho Young;Lee, Gil Hwan
    • Journal of Korean Society of Disaster and Security
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    • v.10 no.1
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    • pp.43-46
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    • 2017
  • Recently, the development of underground space is being actively carried out in the urban area by saturation, and the excavation works are mainly carried out by various excavation methods by the structures adjacent to the ground and underground excavation. During such excavation work, ground subsidence accidents are occurring due to inattention construction, lack of construction technology, and leakage of ground water. For the prevention of ground subsidence we studied the method of risk influence factors by soil investigation. Analysis of 75 sites soil investigation by U.S.C.S (Unified Soil Classification System), construction method, depth of excavation and we studied the risk influence factors with ground subsidence.

Foundation Design Practice for Highrise Buildings in Korea

  • Kim, Sungho;Hong, Seunghyeun;Choi, Yongkyu
    • International Journal of High-Rise Buildings
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    • v.4 no.4
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    • pp.291-310
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    • 2015
  • It is common for tall buildings in Korea to have a ground response that is highly sensitive to the behavior of the structure. Therefore, the geology of the ground needs to be carefully assessed and considered in the design process to accurately predict the performance of the foundation system. This paper sets out a systematic design approach and ground investigation methodology for the soil conditions frequently encountered in Korea. Various foundation design methods are introduced along with several case studies conducted in Korea.

Investigation of Ground Environment Around Underground Oil Storage Facilities Using the Envi-Cone Penetrometer System (환경콘에 의한 지하유류 저장시설주변 지반환경 조사)

  • 정하익;홍승서;김영진;홍성완;곽무영
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.273-280
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    • 2000
  • In recent years there has been a steady increase in geoenvironmental engineering projects where geotechnical engineering has been combined with environmental concerns. Many of these projects involve some investigation of contaminant in the ground. There are many techniques such as geophysical, drilling, sampling, md pushing techniques for investigation of contaminated ground. The most rapidly developing site characterization techniques for geoenvironmental purposes involve direct push technology, that is, penetration tests. The purpose of this study investigated underground oil storage tanks(USTs) using the envi-cone penetrometer system. The electrical resistivity sensor, pH sensor, ORP sensor, and thermometer are installed in envi-cone penetrometer system. This envi-cone penetrometer system provides a continuous profile of measurements, and it is rapid, repeatable, reliable and cost effective for investigation of contaminated ground surrounding the underground oil storage tanks.

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Geotechnical Site Investigation for Designing of Tidal Power Plant Structures (조력발전 구조물 설계를 위한 지반조사;인천만 지반조사 사례)

  • Oh, Myoung-Hak;Lee, Kwang-Soo;Park, Jin-Soon;Yum, Ki-Dai;Cha, Dai-Wook;Yang, Geun-Hun
    • 한국신재생에너지학회:학술대회논문집
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    • pp.613-616
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    • 2007
  • The main structures that comprise a tidal power plant are turbine structure, sluice structure, tide embankment and gate. Since these structures are founded on seabed ground, an extensive geotechnical site investigation to evaluate the engineering properties of field soils must be conducted prior to design and construction. According to the results of geotechnical site investigation conducted at the planned site for construction of Incheon bay tidal power plant, soft ground generally lie 7 meters below the seabed surface level. This research suggests the reliable and economical design of foundations and ground improvements required for construction of main structures in Incheon bay tidal power plant, with considerations on field conditions.

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S-wave Velocity Analysis and Each Survey Comparison of Soft Ground in HoNam High-Speed Railway (호남고속철도 연약지반구간의 전단파 속도분석과 탐사법 비교)

  • Min, Kyong-Nam;Lee, Il-Hwa;Jung, Dae-Ho;An, Tae-Bong;Jung, Chan-Mook
    • Proceedings of the KSR Conference
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    • pp.387-394
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    • 2007
  • This study area located in HoNam High-Speed railway soft ground section. So it carried out the boring survey, field survey and test of laboratory. It collected the engineering data of ground and the data for the establishment arrangement. The investigation did a soil investigation in Nonsan. The investigation item excuted seismic piezocone penetration test, s-wave seismic refraction survey, ps logging test, density logging test which is a physical exploration and boring. Eventually, results of geotechnical and shear-wave survey are useful for ground information in soft ground that has identified the characteristics of geological responses and elastic modulus.

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Study of Influence Factors for Prediction of Ground Subsidence Risk

  • Park, Jin Young;Jang, Eugene;Ihm, Myeong Hyeok
    • Journal of Korean Society of Disaster and Security
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    • v.10 no.1
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    • pp.29-34
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    • 2017
  • This Analyzed case study of measuring displacement, implemented laboratory investigation, and in-situ testing in order to interpret ground subsidence risk rating by excavation work. Since geological features of each country are different, it is necessary to objectify or classify quantitatively ground subsidence risk evaluation in accordance with Korean ground character. Induced main factor that could be evaluated and used to predicted ground subsidence risk through literature investigation and analysis study on research trend related to the ground subsidence. Major factors of ground subsidence might be classified by geological features as overburden, boundary surface of ground, soil, rock and water. These factors affect each other differently in accordance with type of ground that's classified soil, rock, or complex. Then rock could be classified including limestone element or not, also in case of the latter it might be classified whether brittle shear zone or not.

Epidemiologic Investigation to Identify the Cause of an Infant Methemoglobinemia (서울 S지역에서 발생한 영아 메트헤모글로빈혈증 1례의 원인구명을 위한 역학조사)

  • Kim, Young-Yeul;Choi, Bo-Youl;Park, Hang-Bae;Kim, Min-Young;Yeo, In-Hak
    • Journal of Preventive Medicine and Public Health
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    • v.26 no.2
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    • pp.192-201
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    • 1993
  • Epidemiologic investigation was conducted on January, 1993 in Seoul to identify the cause of an infant methemoglobinemia. Field investigation of the area of outbreak, survey of household and family members, analysis of ground water, and blood tests of involved family members were performed. Following results were obtained On analyzing the quality of the ground water on patient's household high levels of nitrate was found indicating contamination of water as the cause of a methemoglobinemia outbreak. On analysing the quality of the ground waters on seven other places within the neighborhood five were contaminated by nitrate in concentration that exceeded the permissible limit implying presence nearby source of contamination. Sources of contamination were thought to be originating from human waste in conventional bathroom facilities, chicken manure used in nearby orchards and plant fields or fertilizers. But the results of water analysis with presence of bacteria or E.coli, concentration of potassium, phosphate and the past history of diarrhea among family members, chicken manure suggested the most possible source of contamination. To evaluate the health status of members in the neighborhood past history was reviewed revealing no prior existence of patient with cyanosis and 65 people in the neighborhood had normal levels of methemoglobin concentration in their blood. Conclusively, the ground water on patient's household was contaminated with nitrate and despite provision of adequate water supply, family members of the patient along with their distrust in the water supply system had used ground water as their source of drinking water resulting of methemoglobinemia. Many suburban area of Seoul and country side thought to be having similar problems concerning contaminated ground water supply and dormant outbreak of patients as a result of the drinking of the contaminated water. Epidemiologic investigation and water analysis of ground waters are advised.

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Analysis of Fire Accident on Power Line for DC Electric Traction Vehicles (전기철도 전원계통에서의 화재사고 사례 분석)

  • Song, Jae-Yong;Cho, Young-Jin;Nam, Jung-Woo;Kim, Jin-Pyo;Park, Nam-Kyu
    • Journal of the Korean Society of Safety
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    • v.25 no.2
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    • pp.18-23
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    • 2010
  • This paper describes a cause of fire accidents on power system fire DC electric traction vehicles. We investigated fire scene of power line for DC electric traction vehicles. From analysis results, the cause of fire on power line turned out line to ground fault between a feeder of electric power services(pantagraph) and DC electric traction vehicle roof. Fire accident of DC electric traction vehicles be assumed that electric sparks had been produced between the pantagraph and the power line conductor by repetitively making contact and separation, maybe if some material like branches get in between connecting rod it makes progress line to ground fault. ZnO arresters are widely used to protect DC electric traction vehicles against overvoltages caused by lightning or switching surges. However, the arresters are deteriorated by commercial overvoltages and/or lightning one. The deteriorated arresters could lead power failures, such as line to ground fault by a thermal runaway resulting from the increases in leakage current even in a nominal power system voltage. Finally, the power failures would be causative of the fire accident.

A Case Study on the Plan for Settlement Restraint by CGS (CGS 공법에 의한 지반침하억제 사례연구)

  • 천병식;여유현;김우종;황성식;김우철
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.611-618
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    • 2002
  • In this study the CGS as an injection method by low slump mortar was performed the pilot test to confirm the applicability of this method and the effectiveness of settlement restraint. From the results, there has been concluded the construction control standard such as an institutional diameter, space, depth, injection materials, Infection pressure etc. Also, there has been estimated the ground improvement effectiveness which has resulted from the field investigation and consolidation test etc. From the results, in the adjacent ground the CGS, generally, has been confirmed to in-crease ground strength to improve the consolidation characteristic obtained from the field investigation and consolidation test. Especially, the CGS which performed the larger stiffness to the ground has been concluded that the settlement restraint to the ground complicates the ground effect which Increases the bearing capacity and stress assignment. So, the CGS can be considered as an effective method to increase the bearing capacity as well as the settlement restraint of soft ground.

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