• Journal of Korean Society of Environmental Engineers
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• v.29 no.2
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• pp.163-168
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• 2007

Ecological risk assessment(ERA) to 5 abandoned mine drainage was investigated by using chemical measurement and bioassay experiment. From the results of chemical analysis, the high concentration of heavy metals are detected in most area. The Arsenite were mostly detected in Songcheon, Nakdong, and Dukum abandoned mine area, and various heavy metals were highly dispersed in Nakdong area. The study area have also high biological toxicity, resulted from the bioassay based on WET(Whole Effluent Toxicity) test by using Vibrio fisheri, Selenastrum copricornutum, and Daphnia magna. The maximum toxicity was shown in the point where the mine waters start to flow. The sensitivity of toxicity by S. capricornutum was relatively high considering the values of toxicity in all samples, from 1.3 to 32.0 TU. The different sensitivities of toxicity recommends the use of battery system, resulted from at least two test species for bioassay or ecological risk assessment of mine drainage. Besides, the results showed high hazard quotient(i.e., greater than 1 HQ value indicating potentially significant toxic risks) with regard to abandoned mine drainage area in this study. On the other hand, the biological toxicity results were sharply decreased by attenuation along further distance from discharging of mine waters. Therefore, environmental parameters including the dilution factor, dissolved organic matter, and hardness should be considered when the remediation and ERA of abandoned mine drainage is planned.

• Journal of Korean Medical classics
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• v.18 no.1 s.28
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• pp.67-72
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• 2005

통과분석(通過分析)${\ulcorner}$동의보감(東醫寶鑑)${\lrcorner}$양명형증용약여포괄중경적(陽明形證用藥？包括仲景的)${\ulcorner}$상한론(傷寒論)${\lrcorner}$재내적주요의학가대양명병적개념(在內的主要醫學家對陽明病的槪念), 득출여하결론(得出如下結論): 1.${\ulcorner}$동의보감(東醫寶鑑)${\lrcorner}$적양명형증용약당중이대편비결위중심, 미사용가이낭괄양명병증재내적위가실저개개념, 상세나열출양명병적구체증상 내급양명병하료정의(來給陽明病下了定義). 병미장대편비결작위대표성증상(幷未將大便秘結作爲代表性症狀), 이시근거표본관계분성경병여부병진행설명. 이기육작위표(以肌肉作爲表), 위작위리적표리개염분석기증상(胃作爲裏的表裏槪念分析其症狀). 2. 기찰급양명병하정의적의서(畿察給陽明病下定義的醫書), 발현제료중경적(發現除了仲景的)${\ulcorner}$상한론(傷寒論)${\lrcorner}$여기주석본성무이적${\ulcorner}$주해상한론(注解傷寒論)${\lrcorner}$이외(以外), 도장목동(都將目疼), 비건(鼻乾), 불득면부간주양명병대표증상(不得眠部看做陽明病代表症狀). 저충정의방식시종송도명대적보편관점 3. 재(在)${\ulcorner}$동의보감(東醫寶鑑)${\lrcorner}$당중작위인용서목적${\lrcorner}$의학입문(醫學入門)${\ulcorner}$, 근거표본(根据標本), 표리개염대증상진행료분류(表裏槪念對症狀進行了分類). 비기지전단순적대증상적서술갱구유조리성. 저가이간주시집당시제다견해지대성(這可以看做是集當時諸多見解之大成), 대병정적분석변적갱가구체. 선택(選擇)${\lrcorner}$의학입문(醫學入門)${\ulcorner}$작위인체서목(作爲引滯書目), 가이인위시채납료당시적최신견해, 병차흡수료용역장악병정적이증상위주적기술방식(幷且吸收了容易掌握病情的以症狀爲主的記述方式). ${\lrcorner}$의학입문(醫學入門)${\ulcorner}$취시집이상관점위일체적대성(就是集以上觀点爲一體的大成). 4. 여태양병당중양형증용약진행비교, 관찰병정적주요관점(觀察病情的主要觀点), 양자도추종료(兩者都追從了)${\lrcorner}$의학입문(醫學入門)${\ulcorner}$적견해(的見解). 단시태양형증용약몰유대몰위초출중경태양병적제망(但是太陽形證用藥沒有大沒圍超出仲景太陽病的提網), 상비지하양명형증용약기몰유인용(相比之下陽明形證用藥旣沒有引用) 중경적(仲景的)${\ulcorner}$상한론(傷寒論)${\lrcorner}$, 대증상적설명야대상경정(對症狀的設明也大相徑庭). 5. 양명형증용약당중몰유인용중경적위가실관점, 이시리용미악한(而是利用微惡寒), 발열(發熱), 갈(渴), 유한(有汗), 목동(目疼), 비건(鼻乾), 조한(潮汗), 폐삽(閉澁), 만갈(滿渴), 광섬, 불면등증상진행설명(不眠等症狀進行說明), 비기장악륭명병작위장부질병(比其掌握隆明病作爲臟腑疾病), 이해위이열위주적상당우양명속성적질병.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.2
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• pp.249-260
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• 2014

When a train enters the tunnel at high speed, the pressure wave occurs. When this pressure wave reaches at the exit of tunnel, some are either emitted to the outside or reflected in tunnel by the form of expansion wave. The wave emitted to the outside forms the impulsive pressure wave. This wave is called 'Micro Pressure Wave'. The micro pressure wave generates noise and vibration around a exit portal of tunnel. When it becomes worse, it causes anxiety for residents and damage to windows. Thus, it requires a counterplan and prediction about the micro pressure wave for high speed railway construction. In this paper, the effects of train head nose and tunnel portal shape were investigated by model test, measurement for the micro pressure wave at the operating tunnel as well as numerical analysis for the gradient of pressure wave in the tunnel. As results, a method for predicting the intensity of the micro pressure wave is suggested and then the intensity of the micro pressure wave is analyzed by the tunnel length and the cross-sectional area.

• Geotechnical Engineering
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• v.14 no.6
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• pp.17-32
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• 1998

The Bakun hydroelectric project includes the construction of a hydroelectric power plant with an installed capacity of 2,520MW and a power transmission system connecting to the existing transmission networks in Sarawak and Western Malaysia, The power station will consist of a 210m height concrete faced rockfill dam. During the construction of the dam and the power facilities the Balui river has to be diverted by three diversion tunnels with a length of some 1,400m each. The inner diameter of the tunnels is 12m and the tunnel width is 16m at the portal area. This paper describes the stability analysis and design methods for the open cut rock slopes in the inlet and outlet area of the diversion tunnels. The geotechnical parameters employed in stability calculations were given as a function of four. defined Rock Mass Types (RMT) which were based on RMR system from Bieniawski. The stability calculations procedure of the rock slopes are divided into two stages. In the first stage, it is calculated for the stability of each 'global' slope without any rock support and shotcrete system. In the second stage, it is calculated for each 'local'slope stability with berms and supported with rock bolts and shotcrete. The monitoring instrumentation was performed continuously and some of the design modification was carried out in order to increase the safety of failed area based on the unforeseen geological risks during the open cut excavation.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.891-894
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• 2008

This study was performed to investigate how to design, where to construct, why to degrade, what plan to use systematically the underground structures such as underpass, underground passageways. About 50% of the underground structures are located on Seoul, Kyungi-Do. In design of the underground structures such as underpass, underground passageways, the required conditions are defined. And also in construction stage, the conditions of soil, required structure depth, site characteristics, reasonable construction method, are investigated. In the selection of details for underground structure, the items mainly considered, are the wall and column type, the sidewalk type, anchoring-system type, the water-proofing method, entranc shape. The reason and the adequate measures for the degradation of concrete structure are also investigated. The initial cracking properties due to the thermal characteristic are considered. The state of the art report on the new technologies are reviewed. The recent project for the systematically application to the underground structures is reviewed.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1330-1336
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• 2007

The purpose of the study was to verify deduction of each coefficient necessary to analysis on micro-pressure waves and reliability of the analysis result. The tunnel running train model testing device used in the test was manufactured by scale of 1:60 and the study used a train model with ten cars long according to specifications of KTX model. The study applied tunnels with cross sections of $107.9m^3\;and\;95.1m^3$ and applied tunnel extensions with 1km, 0.75km and 0.5km. Also, the study tested train speed by changing it into 275, 300, 325 and 350km/h. The test device was a hydraulic launch system composed of a train model, a hydraulic launcher, a tunnel model and a brake. The study measured speed of a model trainby a speed sensor installed in the point of each 1.2m from the front of tunnel entrance and a pithead of tunnel exit and measured pressure change of internal tunnel continuously by installing pressure sensors in the entrance part of tunnel, in the middle part of tunnel and in the exit part of tunnel. As the result of the measurement, it was known that pressure slope of pressure wave happened in the entrance part of tunnel was increased by a nonlinear effect while spreading the tunnel or its pressure slope was reduced by diffusion. Also, the study compared and analyzed micro-pressure waves happened in the exit part of the tunnel by installing each kind of hoods in the entrance part of the tunnel to prevent reduction of micro-pressure waves.

• Journal of the Mineralogical Society of Korea
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• v.29 no.4
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• pp.199-207
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• 2016

One of the most significant environmental issues in abandoned coal mine is acidic drainage which gives rise to the many environmental problems that acidifying streams water, sedimentation of iron/aluminium hydroxide, and pollution of water and soil. Water and precipitate samples for experiments were collected from stream and bottom in the pit mouth of Sambong mine. Mine water shows pH range from 7.24 to 7.94 in winter and 3.87 to 5.73 in summer season. The EC shows range from 432 to $897{\mu}S/cm$ at the stream receiving mine water. The highest concentrations of cations such as Mg, Al, Ca, and Mn are showing 15.50, 4.56, 85.30, 12.76 mg/L in the pit mouth, respectively. The reddish brown precipitates (Munsell color 10R-5YR in winter and 2.5YR-5Y in summer) consist mainly of 2-line ferrihydrite and schwertmannite. The precipitates are characterized by rod or cylindrical forms, and coccus or sphere of 0.1 to $0.5{\mu}m$ in diameter.

• Journal of the Korean GEO-environmental Society
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• v.15 no.6
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• pp.5-15
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• 2014

This study is to quantitatively evaluate the impact on surrounding groundwater of waterway tunnel excavation and cofferdam construction in which A-dam and B-dam, so prediction of groundwater fluctuation and tunnel lining installation was studied. As a result, drawdown of groundwater level during tunnel excavation and cofferdam construction occurred about 3.58 m in the tunnel shaft. The initial condition of groundwater level recovered by up to 90 % was simulated after the completed the construction of the tunnel and lining installation. Groundwater inflow in the tunnel evaluated was analyzed to have exceeding water design criteria of the tunnel. The groundwater inflow is reduced to maximum $0.006m^3/min/km$ after lining installation done in the tunnel, so effect of lining installation was evaluated as 93 % or more. Drawdown of about 0.04~0.31 m occurs in the houses and temples analysis of groundwater system of the surrounding area from construction. Drawdown has occurred nearly by considering annual groundwater level fluctuation of National Groundwater Observation Network.

• Korean Journal of Environment and Ecology
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• v.31 no.1
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• pp.104-111
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• 2017

The construction of road tunnels and bridges have delivered driving efficiency and stability based on developed engineering technology. Tunnels have the advantage of reducing the deforested area compared with other road construction methods. Since a tunnel is an underground passageway dug through the surrounding soil/earth/rock and enclosed except for the entrance and exit, commonly at each end, it does not cause a large amount of deforestation. This study surveyed the deforested areas at each end of the tunnel by the design of the tunnel entrance and exit and forest topography to minimize the amount of deforestation caused by road construction. A survey was done on a total of 150 tunnels (300 entrances and exits) on several main roads in Korea. The deforested area of each tunnel was collected by a breakdown of the entrance area and the upper area of the tunnel. According to the results of Kruskal-Wallis analysis, it was found that there was statistically a significant relation between the location of tunnels and the amount of deforestation by the topographical access type of the tunnels. The tunnel with 'facing orthogonal to incline' type access caused the smallest deforestation while the the tunnel with 'facing to valley' and 'parallel with incline' type accesses caused large deforestation during tunnel construction. Tunnel positioning in the light of topography can reduce the deforested area by up to 1.5ha at each tunnel.

• 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.