• Tunnel and Underground Space
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• v.26 no.2
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• pp.87-99
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• 2016

We developed a Windows-based program for discrete event simulation of truck-loader haulage systems in an underground mine. The Daesung MDI limestone mine located in Samcheok City, Gangwon Province, Korea was selected as the study area to design the program. The developed program is composed of the graphic user interface (GUI) and simulation engine implemented by Visual Basic.NET 2012 and the GPSS/H simulation language, respectively. When a user sets up input parameters for the discrete event simulation through GUI, the program activates the simulation engine, and then simulation results are displayed on GUI. This paper describes the details of the program development as well as its applications to the study area to determine the optimal number of trucks dispatched at each loading point under different operating conditions.

• Journal of the Korean earth science society
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• v.31 no.3
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• pp.205-213
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• 2010

A hydrochemical comparative study of groundwater in uraniferous sedimentary rock of the Ogcheon belt was carried out to investigate the genetic relationship between uraniferous groundwater of Daejeon area and uraniferous sedimentary rocks of the Ogcheon zone. The groundwater shows weak alkaline pH values rangingfrom 6.4 to 8.1 and low Eh values ranging from -50 to 225 mV. The groundwaters to Ca-$HCO_3$ type that shows high concentration of $Ca^{2+}$ and $HCO_3^_$ due to the dissolution of carbonate mineral in limestone. The concentration of uranium in the groundwater was measured very low below $3.2{\mu}g/L$, while it was detected as much as $1165{\mu}g/L$ in the mine waste water. The low Eh value of groundwater is one of the main causes of low uranium concentration of groundwater in uraniferous sedimentary rocks in the Ogcheon belt. It is suggested that the uranium of groundwater in granitic region of Daejeon area was not mainly provided from uraniferous sedimentary rocks in the Ogcheon belt.

• Korean Journal of Plant Taxonomy
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• v.44 no.2
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• pp.136-163
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• 2014

This study was carried out to investigate flora of Golji stream watershed in Gangwon province. The vascular plants which were collected in 11 times (from May 2012 to Nov. 2013) were identified as 825 taxa in total, including 124 families, 420 genera, 730 species, 8 subspecies, 78 varieties, 6 forms and 3 hybrids. In the flora of this area, Korean endemic species were 34 taxa, red list of vascular plants according to IUCN valuation basis were 34 taxa and 165 taxa of specially designated floristic regional indicator plants by the Ministry of Environment. Among those species investigated in this survey, 101 taxa were identified as specific species bio-geographically as compared to flora of other terrestrial regions; 37 of calcicolous plants, 64 with distribution in the northern part of the Korean peninsula. 34 aquatic taxa and 69 naturalized plants were recorded in the investigated area.

• Tunnel and Underground Space
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• v.31 no.4
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• pp.211-220
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• 2021

Tunnel collapse often occurs during deep underground tunneling (> 40 m depth) in South Korea. Natural cavities as well as water supply pipes, sewer pipes, electric power cables, artificial cavities created by subway construction are complexly distributed in the artificial ground in the shallow depths of the urban area. For deep tunnel excavation, it is necessary to understand the properties of the ground which is characterized by porous elements and various geological structures, and their influence on the stability of the ground. This study analyzed geological factors for risk assessment in deep excavation in South Korea based on domestic and overseas case study. As a result, a total of 7 categories and 38 factors were derived. Factors with high weights were fault and fault clay, differential stress, rock type, groundwater and mud inrush, uniaxial compressive strength, cross-sectional area of tunnel, overburden thickness, karst and valley terrain, fold, limestone alternation, fluctuation of groundwater table, tunnel depth, dyke, RQD, joint characteristics, anisotropy, rockburst and so forth.

• Journal of the Korean Society of Groundwater Environment
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• v.4 no.1
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• pp.27-40
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• 1997

The hydrogeochemical study on the 15 natural waters was carried out in the vicinity of tunnel excavation site of Donghae largely composed of granite and limestone. The water samples can be classified based on their chemical characteristics into two groups; waters draining in the granitic region(group 1) and the limestone region(group 2). This classification was also confirmed by statistical examination through cluster analysis, and the tunnel seepage waters collected at the same site appear to be included in group 1 and 2 by their sampling period, respectively. According to factor analysis, the waters of group 1 art mainly represented by the weathering of plagioclase to kaolinite and those of group 2 are characterized by the dissolution of calcite. Different properties of the tunnel seepage waters are thought to be resulted from the effective waterproofing processes conducted during the sampling interval to the surface and subsurface leakage zones at the granitic region, which contributed to the change of groundwater flow system. However both the tunnel seepage waters seem to have thermodynamically interacted with rock-forming minerals in their wallrocks. The mixing ratio of the waters from two groups and water-rock interactions are evaluated quantitatively for the tunnel seepage waters through the mass balance approach, and the results are identical with the previous conclusions in this study.

• Asian Journal of Turfgrass Science
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• v.24 no.2
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• pp.218-224
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• 2010

The purpose of this case study is to analyze the environmental and sociological impacts on a golf course construction at the damaged area of a previous limestone mine. Due to a long term of the open-pit mining, that site had been abandoned with geographical and ecological destruction before it was renovated to Ostar Danyang public golf course. This study is focused on the review of restoring the ecosystem through golf course construction procedures. Literature surveys of restoration through golf course construction in Japan and Canada were analyzed the procedure of utilization of previously existed lime mine. The sociological and environmental changes before and after construction were compared and analyzed. Environmental impacts on geographical, animal and plant ecology, and water quality were not affected or significantly improved after golf course construction from the mining site existed before. The local economy was also improved by increasing employment of resident and tax payment to local government. The construction of golf course could be one of the typical alternatives of ecological restoration of abandoned lime mine. Moreover in this project, minimizing the environmental impacts on surrounding ecosystem was emphasized by a larger size of developing construction. The harmonious lay-out on nature and artificial landscape were also considered a very first stage of construction procedure.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.10
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• pp.1777-1787
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• 2000

The purpose of this study was to select an effective and economical alkali source for sulfur-utilizing autotrophic denitrification. Tests on acid neutralization and denitrification at various alkali/sulfur mixing ratios were performed for charcoal, briquette ashes, sea shell, and limestone. The results of the experiments showed that sea shell was the most effective alkali source because it could provide more surface area than limestone, and the optimal alkali/sulfur mixing ratio was 1/1(V/V). In a sulfur/sea shell packed bed reactor, the denitrification efficiency was above 90% up to a loading rate of 116 g $NO_3{^-}-N/m^3-day$. but the denitrification efficiency deteriorated to 48% at the loading rate of 145 g $NO_3{^-}-N/m^3-day$. The average $SO_4{^{2-}}$ generation per g of $NO_3{^-}-N$ removed was 7.02 g, which is lower than the theoretical value of 7.54 g. Denitrification and sulfate generation appeared to be a first-order and a zero-order reaction with a reaction rate constant of 0.146 /hr and -53.1 mg/L-hr, respectively. According to nitrogen mass balance, 71~109%, with an average of 90%, of the removed nitrogen was recovered as $N_2$ gas.

• Economic and Environmental Geology
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• v.15 no.1
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• pp.41-47
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• 1982

Typical stratigraphic sequences of Paleozoic form the Baegunsan Syncline (equal to Hambaeg Syncline) and Taebaegsan Group is the basement in the southern part of Kangweon Province. Deformation pattern depends on their stratigraphic site and their internal properties. In the biotite schists and meta-sandstones of Pre-Cambrian sequences, flow folds and ptygmatic folds are developed, and high strain deformation is pervasive. Deformational patterns of Cambro-Ordovician are variable because of their various formations. Fracturing is pervasive in the Jangsan Quartzite and Daegi and Maggol Limestone. Welldeveloped slaty cleavage and angular folds of kink and chevron types are the prevailing structures of pelitic rocks. The most characteristic feature of limestone alternated with argillite is the "Compositional cleavage (Author's proposal)" known as the "Worm-eatern" structures. It was known that this structures have a sedimentary origin. But their preferred orienation of long axis of erosional lime holes, originated from tectonic deformation of folding. And this structures have the same character as the axial plane cleavages. Fracturing and long wave concentric folds are dominant characters of the Upper Paleozic sequences. In this area, two folds are superimposed. Field studying and analysis of structures show that the cross-folds of NS-direction are pervasive and were deformed by the EW-directional Baegunsan Syncline. The cross-folding is the major and penetrative deformation and prior to Baegunsan Syncline.

• Economic and Environmental Geology
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• v.53 no.3
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• pp.235-244
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• 2020

Copper (Cu), one of the main contaminants in the mine drainage from the closed mine area, needs to be removed before exposed to environment because of its toxicity even in the low concentration. In this study, passive treatment based field pilot experiments using limestone and compost media were conducted during 9 months for enhancing Cu removal efficiency of the mine water treatment facility of S mine located in Goseong, Gyeongsangnam-do in South Korea. The pH increase and Cu removal efficiency showed high value at Successive Alkalinity Producing System ( SAPS) > Reducing and Alkalinity Producing System (RAPS) > limestone reactor in a sequence. The compost media using in SAPS and RAPS contributed to raise pH by organic material decomposition with generating alkalinity, thus, Cu removal efficiency increased. Also, experimental results showed that Cu removal efficiency was proportional to pH increase, meaning that pH increase is the main mechanism for Cu removal. Moreover, Sulfate Reduction Bacteria (SRB) was identified to be most activated in SAPS. It is inferred that the sulfate reduction reaction also contributed to Cu removal. This study has the site significance in that the experiments were conducted at the place where the mine water generates. In the future, the results will be useful to select the more effective reactive media used in the treatment facility, which is most appropriate to remediate mine water from the S mine.

• Resources Recycling
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• v.21 no.6
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• pp.12-22
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• 2012

This study investigated a utilization technology of light burned dolomite. light burned dolomite ($CaMg(CO_3)_2$) generated in furnace (steel manufacturer) is an alternative to quick lime. Using light burned dolomite has an effect on reducing the consumption of fluorite slag MgO concentration in supersaturated solution by prolonging the life of softening effect. Armophous MgO, not containing periclase is formed by firing dolomite under $800^{\circ}C$. It has larger surface area and higher reactivity than periclase, and also shows better expansion effect than quicklime. Due to those effects, therefore, armophous MgO produced from light burned dolomite is used as an alternative expansion agent in mortar. In the experiment, characteristics of light burned dolomite were compared to those of existing expansion agents such as anhydrite and quicklime. Then, each expansion and shrinkage rates were measured over a period of about 3 months in both of 1m Jis mold at labscale and apartment mortar flooring at field scale. In the result, it was observed that light burned dolomite in mortar flooring more compensates for the expansion and shrinkage rates than the existing expansion agents, showing low expansion rate of below 0.05% and also decreases the crack.