• Resources Recycling
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• v.26 no.2
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• pp.80-88
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• 2017

Globally, there has been a lot of research related to recycling coal ash from power plant stations. This research is happening because there is a considerable shortage of sites for reclamation of increased coal ash every year. In addition, a variety of environmental pollutants have appeared because of mining activity. Abandoned coal mine, pits, and mine tailing piles caused pollutants to come to the surface resulting in serious damage for humans and the environment. Therefore in this study, we investigated whether or not coal ashes have the ability to prevent several environmental problems by mining in Korea and a manageable form recycling coal ashes. In overseas countries, there is a sufficient field of applicable cases where coal ash is used for neutralizing AMD (Acid Mine Drainage), covering of the waste materials, grouting, and soil amendments. However in Korea, since the coal ash is classified as a 'waste', there is an insufficient field applicable cases so far. Therefore it is necessary to establish a specific standard and management system for the utilization of coal ash based on the relevant precedent cases applied abroad in order to prevent environmental pollution caused by mining activity in Korea.

• Geomechanics and Engineering
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• v.19 no.6
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• pp.499-511
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• 2019

The reliability of reinforced concrete structures is frequently compromised by the deterioration caused by reinforcement corrosion. Evaluating the effect caused by reinforcement corrosion on structural behaviour of corrosion damaged concrete structures is essential for effective and reliable infrastructure management. In lifecycle management of corrosion affected reinforced concrete structures, it is difficult to correctly assess the lifecycle performance due to the uncertainties associated with structural resistance deterioration. This paper presents a stochastic deterioration modelling approach to evaluate the performance deterioration of corroded concrete structures during their service life. The flexural strength deterioration is analytically predicted on the basis of bond strength evolution caused by reinforcement corrosion, which is examined by the experimental and field data available. An assessment criterion is defined to evaluate the flexural strength deterioration for the time-dependent reliability analysis. The results from the worked examples show that the proposed approach is capable of evaluating the structural reliability of corrosion damaged concrete structures.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.183-193
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• 2006

Several metalliferous and coal mines, including Seojin and Okdong located at the Kangwon province, were abandoned or closed since 1989 due to the mining industry promotion policy and thus disposed an enormous amount of mining wastes without a proper treatment facilities, resulting in water and soil pollution in the downstream areas. However, no quantitative assessment was made on soil and water pollution by the transport of mining wastes such as acid mine drainage, mine tailing, and rocky waste. In this research, total and fractional concentrations of heavy metals in mining wastes were analyzed and accordingly the degree of water and soil pollutions in the stream area were quantitatively assessed employing the several pollution indices. Concentrations of Ni, Cd, and Pb in soils near the abandoned coal mine areas were 1,240.0, 25.0 and 1,093.0 mg/kg, respectively, and these concentrations were higher than those in soils near the closed metalliferous mine areas. Also Cu concentrations in soils near the tailing dams were about 1967 mg/kg, which is considered as very polluted level. Results demonstrated that soil at the abandoned mine areas were highly contaminated by AMO, tailing, and effluents of the mining wastes. Therefore, a prompt countermeasure on the mining waste treatment and remediation of the codntaminated water and soil should be made to the abandoned or closed metalliferous and coal mines located at the abandoned mine area.

• Geomechanics and Engineering
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• v.17 no.3
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• pp.295-305
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• 2019

The bedding plane has a significant influence on the effect of blasting fragmentation and the overall performance of underground mining. This paper explores the effects of fragmentation of the bedding plane and different angles by using the numerical analysis. ANSYS/LS-DYNA code was used for the implementation of the models. The models include a dynamic compressive and tensile failure which is applied to simulate the fractures generated by the explosion. Firstly, the cracks propagation with the non-bedding plane in the coal with two boreholes detonated simultaneously is calculated and the particle velocity and maximum principal stress at different points from the borehole are also discussed. Secondly, different delay times between the two boreholes are calculated to explore its effects on the propagation of the fractures. The results indicate that the coal around the right borehole is broken more fully and the range of the cracks propagation expanded with the delay time increases. The peak particle velocity decreases first and then increases with the distance from the right borehole increasing. Thirdly, different angles between the bedding plane and the centerline of the two boreholes and the transmission coefficient of stress wave at a bedding plane are considered. The results indicated that with the angles increase, the number of the fractures decreases while the transmission coefficient increases.

• Journal of the Korean Geosynthetics Society
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• v.6 no.4
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• pp.7-13
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• 2007

When the structure such as roadway, railway are constructed on abandoned coal mine area, the countermeasure to prevent settlements is necessary. In this study, numerical analyses are performed to evaluate the effect of the various countermeasures. As a results, the method which is filling the coal mine is more effective than that of reinforcing the ground above the coal mine. The ground settlement decreases hyperbolically with increasing the filling ratio of the coal mine. Also, the relationship between the filling ratio and the settlement reduction ratio is discussed precisely.

• Safety and Health at Work
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• v.5 no.4
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• pp.203-209
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• 2014

Background: Coal mining is of significant economic importance to the Australian economy. Despite this fact, the related workforce is subjected to a number of psychosocial risks and musculoskeletal injury, and various psychological disorders are common among this population group. Because only limited research has been conducted in this population group, we sought to examine the relationship between physical (pain) and psychological (distress) factors, as well as the effects of various demographic, lifestyle, and fatigue indicators on this relationship. Methods: Coal miners (N = 231) participated in a survey of musculoskeletal pain and distress on-site during their work shifts. Participants also provided demographic information (job type, age, experience in the industry, and body mass index) and responded to questions about exercise and sleep quality (on-and off-shift) as well as physical and mental tiredness after work. Results: A total of 177 workers (80.5%) reported experiencing pain in at least one region of their body. The majority of the sample population (61.9%) was classified as having low-level distress, 28.4% had scores indicating mild to moderate distress, and 9.6% had scores indicating high levels of distress. Both number of pain regions and job type (being an operator) significantly predicted distress. Higher distress score was also associated with greater absenteeism in workers who reported lower back pain. In addition, perceived sleep quality during work periods partially mediated the relationship between pain and distress. Conclusion: The study findings support the existence of widespread musculoskeletal pain among the coal-mining workforce, and this pain is associated with increased psychological distress. Operators (truck drivers) and workers reporting poor sleep quality during work periods are most likely to report increased distress, which highlights the importance of supporting the mining workforce for sustained productivity.

• Economic and Environmental Geology
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• v.28 no.4
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• pp.381-388
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• 1995

The petrographic, geochemical, and physical properties of the Jangseong and Chinese coals were investigated. The most common mineral matters of Jangseong coal are kaolinite, muscovite, sericite, illite, quartz and pyrophyllite. Mineral matters in Chinese coal are mainly composed of quartz, calcite, dolomite and kaolinite. Jangseong coal ash has higher content of $Al_2O_3$, $K_2O$, $TiO_2$, As, Rb and V, and lower content of CaO, MgO, $Na_2O$, $Fe_2O_3$ and $P_2O_5$ than those of Chinese coal ash. The liquid limit and the plasticity index of Jangseong coal were compared with those of Chinese coal. The result shows that the briquetting ability of Jangseong coal is a little bit better than that of Chinese coal. The briquetting ability is found to be principally dependent on the type and the content of mineral matter in coal, especially clay mineral.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.45-56
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• 1999

There have been many coal mines abandoned since late 1980s in Korea. Due to the abandoned mines, there have been ground subsidences in some area where are under ground reinforcement works now. So, this study shows the general phenomena of mining subsidence and the procedure of ground reinforcement. In general the procedure for ground reinforcement is as below, 1) obtaining information from inquiries and observations, 2) satellite image analysis and surface geological mapping, 3) analysis of maps of coal mines, 4) geophysical survey and boring test and 5) selection of reinforcement method. The case of reinforcement design at Chul-am area, Kangwon Province is introduced in this article.

• Journal of Environmental Impact Assessment
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• v.10 no.1
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• pp.49-57
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• 2001

With reducing coal mining industry the number of coal mine sites between 1988 and 1998 was dropped from 347 to 12. Since the abandoned coal mine sites have been kept without any cares, they have raised various environmental and safety problems. Then, Korean government initiated a special law in 1995 for enhancing economic conditions and solving environmental problems with promoting developmental projects in the abandoned mining sites. As a result, casino business in Chungsun area has been opened to publics, and other large-scale developments such as ski slopes and resorts are planned. In addition, Boryung area in Chungchung province also will launch a large-scale project building golf courses. Based on this developmental trend, it is expected that lots of large-scale developments in other places will be taken place. In general, the large-scale developments have caused various environmental problems, and, thus, environmental aspects should be considered in a decision-making process. This paper examine the status of the abandoned mine sites in Korea and U.S. and suggests the alternatives of its utilization.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4489-4495
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• 2010

This study aims to examine the current situation of safety education of coal mining industry in Gangwon province, and suggest its problems and improvement directions. And the theoretical background was established through the literature, a survey study for general workers were conducted and its data were analyzed.