• Journal of Industrial Technology
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• v.20 no.A
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• pp.285-293
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• 2000

In 1970's, the analysis of shallow substructure was the interests of geological engineering and environmental problems. And seismic refraction method was applied to detect those structures. From 1980's, digital electric industry is rapidly developed and high resolution prospecting equipment is supplied. And seismic reflection method is applied to achieve various data gathering and data analysis. In this study, geophysical prospecting method is applied to calculate the basic data of limestone yield production. Seismic shallow reflection method is used to detect the depth of bedrock and electrical resistivity method is used to detect of limestone layer boundary.

• Korean Journal of Ecology and Environment
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• v.41 no.2
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• pp.137-143
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• 2008

The abundance and community structure of epilithic diatoms grown on different substrata were investigated in two first-order streams located in a limestone and granite area, north of the Suzuka Mountains in Central Japan. Experiments were conducted as follows: limestone and granite without algae were submerged in their own streambed or another stream station and incubated for seven weeks, while limestone and granite with algae were transferred to another stream station and incubated at the same time. The diatom biomass was consistently high in the lime-stone station experiments compared to those at the granite station. In addition, there was more diatom biomass on granite substrata than on the limestone substrata at both stations. The present results suggested that the difference in water chemistry including the major nutrient concentrations was the limiting factor for algal growth in these two streams; however, when the water chemistry was the same in each stream, the difference in substratum characteristics became the important factor affecting the diatom abundance. The diatom community grown on the transferred substrata with and without algae became similar to those grown on the original substrata in each stream during the incubation period. It was suggested that the effect of the substrata characteristics on the diatom community structure was rather small.

• Journal of Environmental Science International
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• v.4 no.1
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• pp.41-52
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• 1995

The effects of reaction temperature, SO2 and CO2 concentration in an air gas stream, particle sizes of limestone on the reactivity and capacity of SO2 removal have been determined in a thermogravimetric analyser(TGA). The apparent reaction order of sulfation reaction of pre-calcined lime(CaO) with respect to SO2 is found to be close to unity. The apparent activation energies are found to be 17,000 kcal/kmol for sulfation of pre-calcined lime and 19,500 kcal/kmol for direct sulfation of limestone(CaCO3). The initial sulfation reaction rate of pre-calcined lime increases with increasing temperature, whereas the sulfur capture capacity exhibits a maximum value at 90$0^{\circ}C$. In direct sulfation of limestone, sulfation reactivity and sulfur capature capacity of sorbent increase with increasing temperature and decreasing CO2 concentration in a gas bulk stream. The main pare of pre-calcined lime is shifted to the larger pore sizes and pore volume decreases with increasing sulfation time and temperature. The surface area of lime decreases with increasing calcination temperature under an air atmosphere, whereas is yearly constant under a CO2(5, 10%) atmosphere in a gas stream.

• Tunnel and Underground Space
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• v.22 no.5
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• pp.330-338
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• 2012

Though the uniaxial compressive strength (UCS) of rock material is one of the key properties for rockmass characterization purposes, core samples for the test cannot always be obtained from the field. Indirect tests such as the point load test (PLT) can be a useful alternative. In this study, correlation between the UCS and the point load strength index of limestone of Imgye area was analyzed, and the linear regression equation obtained from regression analysis of two variables was suggested. The results of this study were also compared with previous studies on limestone. It was suggested that conversion factors for the same rock type from diverse areas in Korea may have different values, and more data should be obtained to increase the accuracy of regression analysis.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.281-287
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• 2003

A Natural cavities were found at shallow depth during construction of a huge bridge in Moon-Kyung, Korea. The distribution patterns of cavities in the Moon-Kyung limestone were investigated carefully with a supplementary field job such as a structural geological survey, a geophysical survey, and a rock mechanical test in laboratory or field. A structural geological mapping produced a detail geological map on this area. It suggested that there were three faults in this area, and these faults had an influence on the mechanism of natural cavities. Among many kinds of geophysical surveys, an electrical resistivity prospecting was applied firstly on the specific area that was selected by results from the geological survey. Many evidences for cavities were disclosed from this geophysical data. Therefore, a seismic tomography was tested on the target area, which was focused by results from the electrical resistivity prospecting and was believed to have several large cavities. A distinct element numerical simulation using the UDEC was followed on the target area after completing all of field surveys. Data from field tests were directly dumped or extrapolated to numerical simulations as input data. It was verified from numerical analysis that several natural cavities underneath the foundation of the bridge should be reinforced. Based on the project result, finally, most of foundations for the bridge were re-examined and the cement grouting reinforcement was constructed on several foundations among them.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.6
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• pp.72-85
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• 2003

The purpose of this study is to establish the basis of the ecological restoration on the limestone mines in Korea, through the research of the revegetation measures of the disturbed slopes in Japanese limestone mines and the analysis of the case of Ibuki and Bukou limestone mines to realize the restoration works successfully. According to the number of mines to carry out the revegetation works increase every year, the revegetation area and amount of planting also go on increasing in Japan. In the small mines the environmental problem is not recognized seriously, but some mines have muchly invested in the revegetation of the damaged land by mines. Ibuki mine in Shiga-gen is practicing the four principles for the restoring of the revegetation in the disturbed slopes by mines. Firstly, the mean slope preserves $37^{\circ}$ in the last rock cut slopes. Secondly, the last rock cut slopes to rehabilitate are covered with the soil dressing 30cm high. Thirdly, the grasses in the mining area are digged up beforehand, and then they are reused to the revegetation works of rock cut slopes. Lastly, from the upper rock cut slopes the revegetation works begin, the process of the above are repeated, as the result, the restoring works will be completed. Upon the ground of these principles, the complex of the original vegetation and the native species seeding, that is, the revegetation technique of Ibuki have established. In the difficult area to revegetate, sodding works, heaping up vegetation-sack, seed-spraying, heaping up soil-sacks and planting works are adapted variously. Bukou mine in Saitama-gen try to maintain the revegetation, the screening and the stability of the enormous mining rock cut slope, and for these works, the activity of 'Chichibu Working Group of Rock Wall for Limestone Mines' contributes largely. The chief technique of the revegetation in Bukou mine is following; after the making the berm on the rock cut slopes, the soil dressing is filled in it, and the trees is planted for the screening of the rock cut slopes. They devide the rock cut slopes into four typical types, and choose the different ways to make the berm and fill the soil dressing in characteristic. Most of the planting trees are consist ofthe native species of Mt. Bukou through the stages of the nursery and transplantation. Not only the revegetation of the demaged land but also the breeding of the conservational plants also are their important business.

• Economic and Environmental Geology
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• v.52 no.1
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• pp.107-118
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• 2019

Two assertions about the process the formation of the high-purity limestone in the Taebaeksan Basin, categorized into syngenetic and epigenetic origin, are verified on the basis of its oxygen-carbon stable isotopic characteristics. The carbonate rocks sampled from the selective six high-purity limestone mines and several outcrops in the Daegi formation are featured by various colors such as the gray, light gray and dark gray. They show a wide range of oxygen stable isotope ratios (4.5 ~ 21.6 ‰), but a narrow range of carbon stable isotope ratios (-1.1 ~ 0.8 ‰, except for vein calcite), which means that they had not experienced strong hydrothermal alteration. In addition, there is no difference in the range of the oxygen stable isotope ratios by mine and color, and it is similar to the range from surrounding outcrop samples. These results indicate that the effect of the hydrothermal alteration were negligible in the generation of high-purity limestone in deposit scale. Whereas, the carbonate rocks can be divided texturally into two groups on the basis of an oxygen isotope ratio; the massive-textured or well-layered samples (>15 ‰), and the layer-disturbed (or layer-destructed) and showing over two colors in one sample (<15 ‰). In the multi-colored samples, the bright parts are characterized by the very low oxygen stable isotope ratios, compared to the dark parts, implying the increase in brightness of the carbonate rocks could be induced by the interaction between hydrothermal fluid and rock. However, these can be applied in a small scale such as one sample and are not suitable for interpretation of the generation of high-purity limestone as a deposit scale. In particular, the high oxygen isotope ratios from the recrystallized white limestone suggest that hydrothermal fluids are also rarely involved during recrystallization process. In addition, the occurrences of the high-purity limestone orebody strongly support the high-purity limestone in the area are syngenetic rather than epigenetic; the high-purity limestone layers in the area show continuous and almost horizontal shapes, and is intercalated between dolomite layers. Consequently, the overall reinterpretation based on the sequential stratigraphy over the Taebaeksan basin would play an important role to find additional reserves of the high-purity limestone.

• The Journal of Engineering Geology
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• v.26 no.1
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• pp.63-70
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• 2016

The aim of this study is the safety and an accident prevention in limestone terrain by the underground tunneling. The geology of the study area consists of a Paleozoic sedimentary sequence dominated by limestone, sandstone, shale, and carbonaceous shale. The sequence gently dips to the northeast but the joint contains steep with variable trend. A significant fracture zone is developed in the limestone and shale beds, sub-parallel to bedding, and follows in part the limestone-sandstone contact. Monitoring of groundwater levels in the area shows marked fluctuations in the water table, which repeatedly rose to a level of -4 m before sinking to -15 m. These cycles occurred in mid-May, 2007 and in early and middle June. The data indicate that these fluctuations were unrelated to rainfall that occurred during the study period. We infer that the fluctuations were associated with the development of underground karstic networks along the deep fracture zone, and overlying ground subsidence is likely related to the rapid sinking of groundwater and the associated strong downward suction force.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.11a
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• pp.21-38
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• 1999

• Proceedings of the Korean Geotechical Society Conference
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• 1999.11a
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• pp.91-118
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• 1999