• Title, Summary, Keyword: Ground investigation

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Comparison of Accuracy according to Interpolation for Geotechnical Information using GIS (지형공간정보체계를 이용한 지반정보의 보간 방법 정확도 비교)

  • 이종출;강인준;김희규;노태호
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • pp.407-412
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    • 2004
  • As develop of civilization many structure and facilities will constructed forever scientifically and systematically. The prerequisite of those construction have been behaved with plan and investigation of field. When investigation method that ground of distribution and character for many structure are various, many parts of various method have been conducted by the boring method in order to condition, distribution and character for ground. And indirected method of ground investigation data have been interpolated, various methods have been conducted in method of interpolation. Therefore, in this study, we would estimate efficiency that accuracy according to interpolation using the data of ground information by comparable unique density.

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Investigation and Analysis of Soil Contamination at Industrial Site (산업공장 주변 토양오염도 조사 분석)

  • 정하익;김상근
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • pp.99-102
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    • 2000
  • There has been a steady increase in contaminated ground at municipal and industrial site. In this study, investigation and analysis on soil contamination at industrial site was carried out. Testing contaminated soils were sampled at this site. As a result of this study, the concentration of soil was investigated, and measured concentration was compared with related concentration criteria.

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A Study on Fire Investigation Technique For Single Line to Ground Faults in Distribution Line Using EMTP Simulation (EMTP 시뮬레이션을 통한 배전선로의 1선 지락 사고시 화재 조사 기법에 관한 연구)

  • Yoo, Jeong Hyun;Kim, Hie Sik;Lee, Hoon Gi;Cho, Yong Sun
    • Journal of the Korean Society of Safety
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    • v.33 no.3
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    • pp.21-26
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    • 2018
  • Approximately 20% of the total fire is electrical fire, and electrical energy is a potential source of heat. Large-scale fault currents that occur during a line ground fault flow into electric utility poles, electric power equipment, or electric appliances of the customer, and cause simultaneous electrical fire. In this paper, we investigated the possibility of fire through the change of fault current flowing in faulty and sound feeder in case of 1 line ground fault in 22.9 kV distribution line. We propose a fire investigation analysis method for simultaneous multiple electrical fire such as evidence analysis method, and fault current occurrence confirmation method in case of fire accident by analyzing the fault current occurring in the ground fault in the distribution line using EMTP, electric power system analysis program.

Geophysical methods for the investigation of a closed dumping ground

  • Xin, Ling;Chu, Jian;Wang, Jing-Yuan;Yin, Ke;Tong, Huan-Huan;Chia, Charles Y.H.;Mohamed Noh, Omar A.
    • Geomechanics and Engineering
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    • v.8 no.5
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    • pp.727-739
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    • 2015
  • Reclamation of closed dumping grounds is a potential solution to solve land scarce problems. Traditional geotechnical investigations of closed dumping grounds face some problems, such as the emission of hazardous liquids and gases, and the lack of ground information due to the discontinuity between two boreholes. Thus, noninvasive and continuous investigation methods are needed to supplement traditional geotechnical investigations. In this paper, two types of geophysical investigation methods, Seismic Analysis of Surface Waves (SASW) and 2D Resistivity, were carried out to study noninvasive and continuous site investigations for dumping grounds. The two geophysical methods are able to profile the distribution of physical properties of the fill and original materials, by which the extent of the dumping ground can be found and some anomalies in the subsurface can be located. Boreholes were used to assist in locating the dumping material-ground interfaces. The results show that dumping material-ground interfaces obtained from the two geophysical methods are roughly consistent. Moreover, attempt is made in the paper to use the geophysical methods to classify the types of dumping materials. The results show that the classification of dumping materials using the geophysical methods follows the results of the manual sorting of the dumping materials from a borehole.

Experimental and Numerical Investigation of the Performance of Vertical Thermosyphon for Frozen Ground Stabilization (실험과 수치해석을 통한 동토지반 안정화용 수직형 열사이펀의 성능평가)

  • Lee, Jangguen;Lee, Chulho;Jang, Changkyu;Choi, Changho
    • Journal of the Korean Geosynthetics Society
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    • v.13 no.4
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    • pp.45-56
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    • 2014
  • Frozen ground in cold region consists of an upper active layer and lower permafrost which is permanently frozen land. During the summer season, the air temperature is high enough to make the frozen ground melt, which causes the reduction of soil strength and thaw settlement. These phenomena result in structural instability, so it is necessary to apply frozen ground stability techniques. Thermosyphon is a closed natural two-phase convection device to maintain the ground temperature below $0^{\circ}C$ by extracting heat from the ground and discharges it into the atmosphere. Experimental and numerical investigation has been performed to estimate the effect of the refrigerant filling ratio in thermosyphon using R-134a refrigerant and the thermal conductance of the thermosyphon.

A Case Study on the Reinforcement Method of Subway Tunnel (도심지 지하철 터널의 지반보강공법 시공사례 연구)

  • 천병식;여유현;최현석
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.201-208
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    • 1999
  • The NATM(New Austrian Tunnelling Method) has been used for tunnelling since 1980's. But Collapses of tunnel under construction take place frequently, especially at urban areas because of adjacent buildings, underground conduits and traffic loads. This paper is a case study on the reinforcement method of subway tunnel at urban areas. In this study, ground inspection, geological investigation, laboratory test and numerical analysis by means of FDM program were carried out. The tunnel excavation was stopped because of over excessive brake of tunnel crown and shotcrete was installed to prevent deformation of adjacent ground as the temporary method. From the result of field survey and geological investigation, it is found that the soft weathered soil was distributed to the ground of tunnel invert unlike original investigation. The results of the analysis and the study show that the SGR(Space Grouting Rocket) method and Umbrella method can be applied for the stability of tunnel excavation and in addition the reinforcement of concrete lining is required for long-term stability of tunnel.

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A Study on the Development of Envi-Cone Penetrometer System (지반환경조사용 환경콘 관입시스템 개발을 위한 기초연구)

  • 정하익;홍승서;김영진;홍성완;곽무영
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.247-254
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    • 1999
  • 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, and 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. In this study, the envi-cone penetrometer system is developed by modification of traditional cone penetration test. The electrical resistivity sensor, pH sensor, 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.

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Investigation and Assesment of Ground Contamination around Waste Landfill (폐기물매립지 주변 토양 및 지하수 오염도 조사 및 분석)

  • 정하익;김상근
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • pp.116-119
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    • 2000
  • 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 on contaminant and leachate flume in the ground and landfill. In this study, investigation and assesment on soil and groundwater around the waste landfill was carried out. Many techniques such as drilling and sampling method were applied. As a result of this study, the concentration of soil and groundwater were investigated and analysed.

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Community structure and distribution of ground beetles (Coleoptera: Carabidae) in Sobaeksan National Park, Korea

  • Hong, EuiJeong;Kim, Youngjin;Jeong, Jong-Chul;Kang, Seung-Ho;Jung, Jong-Kook;Suk, Sang-Wook
    • Journal of Ecology and Environment
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    • v.41 no.4
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    • pp.125-131
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    • 2017
  • The ground beetles collected during the investigation period were nine subfamilies, 24 genera, 51 species, and 3504 ground beetles. Species richness was high in Pterostichinae has 24 species (47%), Harpalinae nine species (17.6%), Carabinae six species (11.8%), and Lebiinae three species (5.9%). Overall dominant species was Synuchus agonus, and dominance index was 0.361. Synuchus agonus was investigated as the dominant species in both Namcheon Valley and Geumseon Valley. Regarding subdominant species, it was Synuchus nitidus (52 individuals, 12.6%) and Synuchus cycloderus (52 individuals, 12.6%) in the order in Namcheon Valley, and it was Pterostichus orientalis orientalis (660 individuals, 21.3%) and Pterostichus audax (378 individuals, 12.2%) in the order in Geumseon Valley. Total species diversity index of ground beetles in Sobaeksan National Park was 2.917. By area, the number of collected ground beetles was smaller in Namcheon Valley than in Geumseon Valley. Sobaeksan National Park is located at the boundary of northern and southern parts in Korea and is a very important place in terms of geography and climate. Sobaeksan has been designated as a national park, and its ecosystem is relatively preserved well. If continuous investigation of basic data for ground beetles is conducted through long-term monitoring, the data can be used as key data to research mutual relationship with organisms, effects by climate change, and ecosystem change depending on human activities.

Laboratory investigation of the effects of translation on the near-ground tornado flow field

  • Razavi, Alireza;Sarkar, Partha P.
    • Wind and Structures
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    • v.26 no.3
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    • pp.179-190
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    • 2018
  • Translation of tornadoes is an important feature in replicating the near-ground tornado flow field which has been simulated in previous studies based on Ward-type tornado simulators using relative motion of the ground plane. In this laboratory investigation, effects of translation on the near-ground tornado flow field were studied using the ISU Tornado Simulator that can physically translate over a ground plane. Two translation speeds, 0.15 m/s and 0.50 m/s, that scale up to those corresponding to slowly-moving tornadoes in the field were selected for this study. Compared with the flow field of a stationary tornado, the simulated tornado with translation had an influence on the spatial distribution and magnitude of the horizontal velocities, early reversal of the radial inflow, and expansion of the core radius. Maximum horizontal velocities were observed to occur behind the center of the translating tornado and on the right side of its mean path. An increase in translation speed, resulted in reduction of maximum horizontal velocities at all heights. Comparison of the results with previous studies that used relative motion of the ground plane for simulating translating tornadoes, showed that translation has similar effects on the flow field at smaller radial distances (~2 core radius), but different effects at larger radial distances (~4 core radius). Further, it showed that the effect of translation on velocity profiles is noticeable at and above an elevation of ~0.6 core radius, unlike those in studies based on the relative motion of the ground plane.