• 한국안전학회지
• /
• 제17권4호
• /
• pp.25-30
• /
• 2002

This paper demonstrates the effects of dust electrical resistivity on electrostatic precipitability. The effects of gas temperature, velocity and humidity on the collection efficency were considered by used of coal fly ashes from fluidized bed combustion boiler. The experiments for collection efficiency were carried out in the pilot plant. The ashes which have non-spherical geometry and high electrical resistivity were used. Electrical resistivity is an important property for the collection efficiency in the electrostatic precipitators. Fly ash resistivity as a function of temperature up $350{\circ}C$ and water concentration(up to 15%) has been experimentally investigated using the resistivity test equipment consisted of the movable electrode, dust cup, and furnace. As the resistivity of fly ash in the operating temperature($150{\circ}C$) of an electrostatic precipitator was measured higher than $1010{\Omega}{\cdot}$cm, flue gas conditioning in the electrostatic precipitator to reduce the resistivity of fly ash is required.

• 자원환경지질
• /
• 제13권3호
• /
• pp.159-166
• /
• 1980

A model study was conducted for the investigation of apparent resistivity variation along with electric resistivity variation of host rock and dip variation of bed. Experiments were carried out for the cases of horizontal and dipping beds in a water tank by using Wenner and Schlumberger arrays and by changing salinity of water. The ratios of resistivity values of the bed to that of brine were 1 : 10, 1 : 50, 1 : 100 and 1 : 500. Natural coally-shale of $55cm{\times}35cm{\times}3.5cm$ was used as a bed for experimental model, and brine as a host rock. Equi-resistivity curves and characteristic curves were obtained for each case of the experiment. The equi-resistivity curve was drawn both on the cross section parallel to strike of bed and longitudinal section perpendicular to it. The characteristic curve was drawn on the cross section. In the case of dipping bed of different dips, the curves are parallel to the boundary of the bed in the upper part of the bed, and are inclined to the opposite direction with the same angle of the dip of bed in the lower part. We can deduce, from the equi-resistivity curves, the location, shape and dip of the bed. It is shown in the characteristic curves that when the ratio of resistivity value of bed to that of host rock increases, the slope of curves becomes steeper, location of low-resistivity zone lower, and the width of it narrower. The slope of curves also becomes steeper when dip of bed increases. We can deduce, from the characteristic curves, the ratio of resistivity values between adjacent beds. It was found out from the experiments that electric resistivity method could be applicable to prospecting for underground geology with an electric resistivity contrast of 1 : 10. This fact strongly suggests that distinction of coal from coally-shale could be possible in a certain field condition.

• 한국지반공학회논문집
• /
• 제29권5호
• /
• pp.53-64
• /
• 2013

전기비저항 모니터링 탐사법은 공극의 변화는 입자와 함수율의 변화에 기인한다는 사실에 근간을 두고 있다. 모든 댐에서 내부 침식은 시간이 지날수록 발생하며, 시간이 지남에 따라 누수가 집중되고 결국 댐의 파괴에 이르게 한다. 전기비저항은 제체내 공극의 변화에 매우 민감하게 변화하는 것으로 알려져 있어 전기비저항 모니터링 탐사법은 누수탐지에 효과적으로 적용되어 왔다. 그러나 전기비저항은 온도의 계절 변화와 총고용용존물, 운영수위 등의 변화에 큰 영향을 받는다. 본 논문에서 우리는 댐마루 중앙부에 영구적으로 전극을 설치하고 2011년 4월 3일부터 2012년 7월 31일까지 매 6시간 마다 전기비저항 모니터링 탐사 자료를 획득하였다. 모니터링 데이터의 해석을 위해 각 전기비저항 데이터의 2,950여개가 넘는 데이터를 분석하였다. 그 결과 전기비저항은 온도의 영향으로 계절변화에 따라 변화함을 확인할 수 있었으며, 전기비저항 모니터링탐사로부터 제체의 공극률을 산출하고 분석하였다. 댐체에서 전기비저항 모니터링 탐사의 적용성과 안정성을 확인하였으며, 신뢰할 만한 전기비저항 모니터링 데이터의 중요성을 강조할 수 있었다.

• 한국농공학회논문집
• /
• 제51권6호
• /
• pp.33-43
• /
• 2009

This study analyzed data on the pore water pressure, the ground water level, the horizontal displacement and the resistivity monitoring from instrument system, which is established to evaluate the safety in reservoirs. The pore water pressure in the embankment ranged from $0.035{\sim}1.116kg/cm^2$. The seepage that piping showed, as well as the leakage from the reservoirs are acceptable for the safety management of the reservoir. The maximum horizontal displacement and direction analyzed from the measured inclinometer data gives us very effective information to evaluate the safety in reservoirs. The resistivity monitoring technique, which is obtained on the reservoir crest, is an efficient tool to detect leakage zone. The safety index (SI) was predicted by the resistivity monitoring, and was evaluated to have a safety level of 0.8-1.0 at all reservoirs. Safety evaluations of reservoir through instrument systems are effective when studying the embankment, when the results of the instrument system have been analyzed compositively.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2010년도 춘계 학술발표회
• /
• pp.840-851
• /
• 2010

This study analyzed data on the pore water pressure, the ground water level, the horizontal displacement and the resistivity monitoring from instrument system, which is established to evaluate the safety in reservoirs. The pore water pressure in the embankment ranged from $0.035{\sim}1.116kg/cm^2$. The seepage that piping showed, as well as the leakage from the reservoirs are acceptable for the safety management of the reservoir. The maximum horizontal displacement and direction analyzed from the measured inclinometer data gives us very effective information to evaluate the safety in reservoirs. The resistivity monitoring technique, which is obtained on the reservoir crest, is an efficient tool to detect leakage zone. The safety index(SI) was predicted by the resistivity monitoring, and was evaluated to have a safety level of 0.8-1.0 at all reservoirs. Safety evaluations of reservoir through instrument systems are effective when studying the embankment, when the results of the instrument system have been analyzed compositively.

• 한국지구물리탐사학회:학술대회논문집
• /
• 한국지구물리탐사학회 2007년도 공동학술대회 논문집
• /
• pp.307-312
• /
• 2007

Seawater intrusion in estuarine regions is an important issue in protecting groundwater against salinity increase as well as in protecting construction materials against corrosion. For example, drain water ejected during accelerated consolidation for the improvement of soft ground can cause damages to farm land because the drain water from seawater intrusion zones contains salinity. In this study, we have employed correlation analysis between resistivity value and salinity of in situ pore water. The correlation analysis indicates that resistivity and salinity are in exponential relationship with good correlation. Therefore we suggest that rapid estimation of spatial distribution of NaCl is possible using resistivity data.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2010년도 추계학술대회 초록집
• /
• pp.199.1-199.1
• /
• 2010

Use of recycled aggregates that are constituents of concrete or asphalt-based structures has become popular because the recycling is an eco-friendly way to overcome the depletion of natural aggregates. In order to adopt the recycled aggregates for backfilling a power transmission pipeline trench, their thermal resistivity should be low enough to prevent thermal runaway in the transmission system. In this study, a series of laboratory tests with QTM-500 and KD2 Pro was performed to measure the thermal resistivity of recycled aggregates prepared from various sources. Relationships between the thermal resistivity of recycled aggregates and the water content have been obtained with consideration of compaction effort. Similar to natural soils, the thermal resistivity of the recycled aggregates decreases with increasing the water content. In addition, this study compared the experimental data with conventional prediction models for the thermal resistivity in the literature, which suggests the availability of the recycled aggregates as backfill material substituting for natural aggregates when backfilling the power transmission pipeline trench.

• Geomechanics and Engineering
• /
• 제24권1호
• /
• pp.1-14
• /
• 2021

In this study, a new approach using electrical resistivity measurement was proposed to detect grout penetration and to evaluate the grouting performance for such as waterproof efficiency in single rock fracture. For this purpose, an electrical resistivity monitoring system was designed to collect multi-channel data in real time. This was applied to a system for grout injection/penetration using a transparent fracture replica with various aperture sizes and water-cement mix ratio. The electrical resistivity was measured under various grout penetration conditions in real time, which results were directly compared to the visual observation images of grout penetration/distribution. Moreover, the grouting success status after the curing process was evaluated by measuring the electrical resistivity in relation to changes in frequency in fracture cells where grout injection and penetration were completed. Consequently, it was determined that the electrical resistivity monitoring system could be applied effectively to the detection of successful penetration of grouting into a target area and to actual field evaluation of the grouting performance and long-term stability of underground rock structures.

• 한국지반환경공학회 논문집
• /
• 제16권8호
• /
• pp.21-35
• /
• 2015

본 연구에서는 국내 3개 필 댐의 ECRD(Earth Core Rock-fill Dams) 댐체의 코어존에 대한 건전성 평가를 목적으로 2차원 및 3차원 전기비저항 탐사를 수행하였다. 2차원 전기비저항 탐사 결과, 대부분의 점토재로 축조된 코어존은 $50{\sim}400ohm{\cdot}m$ 이하의 저비저항대로 나타났으며, 그 하부의 기반암은 $1,000ohm{\cdot}m$ 이상의 고비저항대로 나타났다. 또한 3차원 전기비저항 탐사 결과에 의하면 코어존의 연약대로 판단되는 $100ohm{\cdot}m$ 이하의 저비저항대의 공간적인 분포영역을 확인할 수 있었다. 아울러 코어존의 토질시료 특성을 파악하기 위하여 시추조사와 토질 실내시험을 수행하였다. 시추조사 시 굴착수에 의한 댐체 내의 구조적 훼손을 방지하기 위하여 무수보링 방법을 택하였다. 그 결과 저비저항대로 나타나는 코어존의 시료는 모두 통일분류상 CL에 해당되며, 일부 저비저항대에서는 함수비가 높은 포화상태의 시료가 관찰되었다. 이러한 결과를 통해 ECRD 댐체 코어존의 건전성 평가에 전기비저항 탐사와 무수보링의 적용성은 매우 효율적인 방법이라 판단된다.

• 한국지반공학회논문집
• /
• 제30권10호
• /
• pp.19-31
• /
• 2014

원심모형실험 중 지반모형의 상태 변화를 입체적으로 파악하기 위한 방법으로 전기비저항 탐사를 시도하였다. 탐사 시스템은 현장에서 널리 사용되는 검증된 상용 장비를 바탕으로 하였다. 컴퓨터 원격 조정으로 실험 시설 내에 설치된 탐사 장비를 통제하고 실시간 해석을 통해 결과 영상을 원심 모형실험 중에 바로 확인할 수 있도록 구성하였다. 구축된 탐사 시스템의 안정적 구동 여부를 점검하기 위해 불포화상태로 조성된 모형 지반 상단에 염수를 떨어뜨려 지반 내부로 이동하게 하고 전기비저항 탐사를 수행하였다. 10g로 원심력을 가한 상태에서 실험을 수행하고 시간대별 염수 침투상황을 전기비저항 영상으로 확인하였으며 일반 중력장에서 동일하게 실험한 결과와 비교하였다. 실험 종료 뒤 모형지반 수직 절단면을 이용하여 직접 측정한 전기비저항 값과 획득한 영상을 비교함으로써 신뢰성을 검증하였다.