• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.546-552
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• 2010

Seasonal frozen ground affects structural behavior in South Korea. Frost and heaving of seasonal frozen ground results in the critical damage of roadway, railroad, and buried pipeline. It has been widely used to substitute frost susceptible soils with granular soils. This paper presents experimental investigation on the effectiveness of soil-shredded tire and soil-expanded polystylene (EPS) mixtures to reduce frost depth and force around a buried pipeline. Experimental data such as measured temperature profile and the deformation of buried pipeline were carefully observed and provide the evidence of the effectiveness of soil mixtures.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.1014-1019
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• 2004

The development of both economical and consistent structure is strongly required for the whole reorganization of the railway network in Korea. Retaining wall is one of the major structures in the vicinity of the railway, which needs improving its external appearance and stability. Therefore, this study presents a new type of retaining wall, so called short-fiber composite reinforced retaining wall, as an alternative of retaining walls, which can be used for constructing the slope and roadbed soil structures. The results from real-scale test and dynamic numerical analysis for developed new one, which helps both the improvement of the external appearance and also the optimum use of the limited space near the railway, show excellent performance. On the basis of these results, it is judged that short-fiber composite reinforced retaining wall has the advantages of choosing the front wall freely and having a chance to use any low quality soil as backfill.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.597-603
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• 2005

The remediation of railroad contaminated soil is gaining wide attention, recently. In railroad field, modification of diesel supply field, equipment of roll pad, FRP panel, and iron pannel under diesel locomotive storages are used for the prevention of contamination expansions. However, cheap and efficient remediation technology has not been suggested yet. In this study, the contaminated ballast was remediated by blasting technology. Because the contaminants mainly resides on the surface of ballast, blasting these contaminants make it available to recycle the ballast. We carried out the remediation of oil-contaminated ballasts using the blasting technology, and we could remediate them nicely. This technology is expected to be used for the cheap and quick remediation of contaminated ballast.

• Geomechanics and Engineering
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• 제21권2호
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• pp.143-152
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• 2020

Korean society experienced successive earthquakes exceeding 5.0 magnitude in the past three years resulting in an increasing concern about earthquake stability of urban infrastructures. This study focuses on the significant aspects of earthquake risk assessment for the cut-and-cover underground railway station based on two-dimensional dynamic numerical analysis. Presented are features from a case study performed for the railway station in Seoul, South Korea. The PLAXIS2D was employed for numerical simulation and input of the earthquake ground motion was chosen from Pohang earthquake records (M5.4). The paper shows key aspects of earthquake risk for soil-structure system varying important parameters including embedded depth, supported ground information, and applied seismicity level, and then draws several meaningful conclusions from the analysis results such as seismic risk assessment.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.448-453
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• 2005

Tunnel excavation is an inevitable process for railroad construction in Korea and it being a one of the major issues of its environmental impact assessment. Ground water flow by tunnel excavation is an important parameter to determine environmental effects. The current method to determine the ground water flow is used a unit number induced a highway construction site. But it does not consider any site characteristics; ground water level, soil properties and others. The purpose of this study is to suggest the determination way of ground water flow considering site characteristics in tunnel construction.

• 한국환경보건학회지
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• 제38권6호
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• pp.529-540
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• 2012

Objective: This research was performed to evaluate the state of oil pollution in an area surrounding a railway station that has over 100 years of business history as a railway station in S City, Korea. The amount of polluted soil was estimated, and the target area for remediation was assessed in this study to restore the oil-polluted area. Methods: To accomplish this aim, five observation wells were installed for the sampling of groundwater, and soil was sampled at 33 points. Electric resistance studies and a trench investigation were undertaken to understand the geological conditions of the site, and the groundwater movement in this area was simulated by MODFLOW. Physiochemical analyses were conducted to determine the quality of the groundwater and the current state of oil pollution influenced by that of the soil. Results: The mean level of total petroleum hydrocarbons (TPHs) in this area was 1,059 mg/kg, and the area for remediation was determined to be 7,610 mg/kg. Levels of benzene, toluene, ethylbenzene, and xylene (BTEX) were determined to be under the legal standard. Conclusion: In terms of depth, the biggest area polluted by TPH found was between 0 and 1 m from ground level, and the affected area was 5,900 $m^3$. TPHs were not detected in groundwater. Diesel and lubricating oil were the main causes of TPH pollution at this railway station.

• 한국지하수토양환경학회지:지하수토양환경
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• 제12권3호
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• pp.17-22
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• 2007

납으로 오염된 실제 토양을 처리하기 위해 토양세척기술의 적용성을 평가하였다. 세척제로는 염산을 사용하였으며, 0.2 M 염산을 사용하여 고액비 1:3으로 하여 10분간 접촉하여 2회 세척하여준 결과 96%의 제거율을 보였다. 세척액과 토양의 접촉시간을 5분에서 120분까지 증가하였을 때, 제거효율은 69.3%에서 81.9%로 증가하였다. 입경별 토양세척 효율은 온도와 교반시간에 영향을 받았으며, 20분 이상 교반하여 준다면, 0.075 mm 이하, 0.075 mm-2.0 mm, 2.0-4.0 mm 의 입경별 토양에서는 모두 99%의 제거효율을 보였다. 이상의 결과는 본 연구에 사용된 납 오염 토양은 토양세척기술을 적용하여 효과적으로 처리할 수 있는 것을 의미한다.

• 한국지반공학회논문집
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• 제33권8호
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• pp.5-16
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• 2017

근입깊이가 직경에 비하여 상대적으로 작은 말뚝은 편심이 큰 횡방향 하중을 받는 경우 전도되어 파괴된다. 지금까지 횡방향하중을 받는 짧은말뚝의 지지거동에 대해서는 주로 모형실험을 적용한 연구가 수행되었지만, 전주, 표지판, 가로등 기초와 같이 매우 큰 모멘트를 받는 짧은말뚝의 지지거동은 아직까지 명확히 규명된 바 없다. 본 연구에서는 직경 750mm의 실물크기 말뚝에 대한 재하시험을 수행하였다. 실제 하중조건을 모사하기 위하여 기초로 부터 8m 이격된 지점에 횡방향 하중을 가하여 매우 큰 모멘트를 유발하였으며, 말뚝의 근입깊이를 2.0m, 2.5m, 3.0m로 변화시킨 3회의 시험을 수행하였다. 시험결과 큰 모멘트를 받는 짧은말뚝은 파괴 직전까지 변위나 회전각이 거의 발생하지 않다가 전도로 인해 급격한 변위가 발생하는 취성형태로 파괴 되었다. 이러한 거동은 기존의 횡방향 위주의 하중을 받는 짧은말뚝에서 나타난 연성파괴 거동과는 대조적이다. 기존에 제안된 세 종류의 지지력 예측식으로 부터 구한 짧은말뚝의 극한 횡방향지지력을 시험결과와 비교하였으며, 말뚝 근입깊이가 상대적으로 작은 경우는 말뚝선단 중심의 회전을 가정한 제안식이 적절하지만, 근입깊이가 커지면서 회전점을 중심으로 응력방향이 반전되는 토압분포를 가정한 제안식이 보다 적절한 것으로 평가되었다.

• 한국대기환경학회지
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• 제27권5호
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• pp.523-533
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• 2011

This study had the aim of characteristics of $PM_{10}$ in subway cabins. $PM_{10}$ was measured by times of day (rush and non rush hours) and seasons with real time $PM_{10}$ sampler on the subway cabins of line 7. Filter samples were collected for evaluation of their elemental composition as well as identification of major sources of $PM_{10}$ using a receptor model, PMF. $PM_{10}$ concentration were the highest in the winter season both in the rush and non rush hours at 152.8 ${\mu}g/m^3$, 90.2 ${\mu}g/m^3$ respectively. The $PM_{10}$ concentrations in rush hour were 30% higher compared to non rush hours. Based on the chemical information, the composition rare of inorganic elements was 52.5%, anions were 10.2% and others were 37.3%. Fe was the most abundant element and significantly correlated (p.0.01) with Mn (r=0.97), Ti (r=0.91), Cr (r=0.88), Ni (r=0.89) and Cu (r=0.88). Characterized $PM_{10}$ sources by PMF in the cabin were soil and road dust related sources (27.2%), railroad related sources (47.5%), secondary nitrate sources (16.2%) and a Cl-factor mixed with a secondary sulfate source (9.1%).

• 한국지반공학회논문집
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• 제20권2호
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• pp.5-13
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• 2004

기존의 흙을 사용하여 건설된 철도 노반은 반복적인 교통하중의 증가, 열차속도의 향상, 노반상으로의 지하수의 유입, 노반의 배수능력 저하 등의 이유로 인해 시간경과에 따라 쉽게 그 기능을 상실할 수 있다. 본 연구에서는 실대형시험과 수치해석을 수행함으로씨 철도노반으로서의 쇄석강화노반의 성능을 평가하였다. 쇄석강화노반의 탄$.$소성 연직변위는 모사열차하중의 재하횟수에 관계없이 일반 흙노반에 비해 작은 응답특성을 보였으며, 동일한 노반 부설두께에서는 노반반력계수의 증가에 따라 감소하며, 동일한 강성인 경우 노반 부설두께 증가에 따라 감소하는 경향을 보였다. 하지만, 쇄석강화노반의 부설두께에 비해 노반의 강성이 궤도에 발생하는 전체 소성 연직변위에 더욱 큰 영향을 미치는 것으로 평가되었다.