• 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.

• Journal of Environmental Science International
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• v.14 no.8
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• pp.719-722
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• 2005

This study is to find the effective way to green perpendicular wall spaces as soon as possible and to get basic data for activating the perpendicular greening on high story building through the experiment of container-type planting ground in which lightened artificial soil mixed with rock wool was put. Comparative studies of the sizes of containers and soil were carried out but separate management was not performed. Four plants(Euonymus fortunei var. radicans, Lonicera japonica, Parthenocissus quinquefolia, Parthenocissus tricuspidata) which have the capability to cover and screen perpendicular spaces were used in the experiment. In result, a container must be equipped with over 15cm depth soil mixed with less than $30\%$ of rock wool.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.09a
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• pp.81-92
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• 2000

Green Slope(F.F.R : Fabric Form Reinforcement Method) is one of an environmental slope protection method at steep cutting sites. This method is that soil and rock at the steep slope is fixed using the environmental Fabric Form, Nail, Rock Bolt and Rock Anchor, And then, the surfaces covered with grasses or weeds. This method will be satisfied both safe slope protection and natural environment appearance. Green Slope is a useful method of the construction sites of steep cutting slopes.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2006.09a
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• pp.59-79
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• 2006

The successful execution of shield tunnelling depends on the cutting ability of cutter. So the selection of shape, size and material of cutter according to geology condition is important work. Since shield tunnelling method was first invented in 1881, the cutting tool for rock has been developed owing to various experiments and researches, the study for soil, however, is insufficient. This paper introduces the shield tunnelling that will be carried out on weathered rock section (920m) of Seoul Subway Line 7 Extension C703. The shape and the material of cutter are discussed required for execution without replacement of cutter tool as well as for advance of excavation efficiency. In addition the estimation method of cutter abrasion in case of excavation on weathered soil is proposed and verified. Specially, the coefficient of abrasion for different soil and cutter is proposed by means of investigation into construction example of foreign country.

• Journal of the Korean Geotechnical Society
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• v.24 no.12
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• pp.33-40
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• 2008

The load distribution and deformation of rock-socketed drilled shafts subjected to axial loads are evaluated by a load-transfer method. The emphasis is on quantifying the effect of coupled soil resistance in rock-socketed drilled shafts using the 2D elasto-plastic finite element analysis. Slippage and shear load transfer behavior at the pile-soil interface are investigated by using a user-subroutine interface model (FRlC). It is shown that the coupled soil resistance provides the influence of pile toe settlement as the shaft resistance is increased to an ultimate limit state. The results show that the coupling effect is closely related to the value of pile diameter over rock mass modulus (D/$E_{mass}$) and the ratio of total shaft resistance against total applied load ($R_s$/Q). Through comparisons with field case studies, the 2D numerical analysis reseanably presented load transfer of pile and coupling effect due to the transfer of shaft shear loading, and thus represents a significant improvement in the prediction of load deflections of drilled shafts.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.2
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• pp.80-84
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• 2014

Phosphorus (P) is an essential nutrient for all living organisms. P is mostly obtained from mined rock phosphate. However, existing rock phosphate reserves could be exhausted in the next 50-100 years. As Korea is totally dependent on imported rock phosphate, we should seek for solution to overcome the P depletion by efficient use and recycling. For this, this study suggested a P flow model to identify the location and flow route of P in urban area based on traditional material flow analysis. The type of P entering the urban areas are fertilizer, food and feed. Each type of P is used in agriculture, human consumption and animal husbandry. After going through each process, P is moved to waste management facilities within food waste, excreta and sewage. Some portion of P in waste are buried, incinerated and discharged, which can be reservoir of P in the future.

• Tunnel and Underground Space
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• v.20 no.1
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• pp.7-14
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• 2010

A quarry with 105 m height large cut slope was analyzed. Beside RMR and SMR methods, FLAC2D were adopted to analyze slope stability. As a result, slope of andesite had a possibility of failure. Wet slope showed low safety factor. Soil nailing was recommended to solve it. Since safety factor of slope largely depend on underground level, investigation for it seemed necessary.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.394-398
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• 2004

This study was carried out to plan the prevention of the generation and discharge of acid mine drainage (AMD). Hydraulic characteristics were tested with the disk tension infiltrometer around the waste rock dump of the Imgi abandoned pyrophyllite mine in Busan, Korea. Because the waste rock dump of the Imgi mine have very low infiltration rate, most of rain was expected flowing into adjoined stream through the slope or plane as surface flow rather then throughflow or ground water. But slopes of the waste rock dump have many 'V' type erosion gullies and consist multi-layers. These gullies and multi-layers have coarse clastic particle layer which have very large hydraulic conductivity. So through these coarse clastic particle layers a large part of rain flow into ground. And also these layers could be played a function of aeration path, which induced oxidation of sulfide minerals and generation of AMD continuously.tinuously.

• Journal of the Korean Geotechnical Society
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• v.30 no.2
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• pp.43-52
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• 2014

This paper examined the effect of step-wise excavation depth on the earth pressure against an excavation wall in rock mass. Numerical parametric studies were conducted based on the Discrete Element Method (DEM) to carry out the problems in rock mass. Controlled parameters included step-wise excavation depth, rock types, and joint conditions (joint shear strength and joint inclination angle). The magnitude and distribution characteristics of the induced earth pressure in a jointed rock mass were investigated and compared with Peck's earth pressure for soil ground. The results showed that the earth pressure against an excavation wall in rock mass were highly affected by different rock and joint conditions, and the effect of step-wise excavation depth increased as a rock type is deteriorated more. In addition, it was found that the earth pressure against an excavation wall in rock mass might be considerably different from Peck's empirical earth pressure for soil ground.

• Journal of the Korean Geotechnical Society
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• v.33 no.11
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• pp.83-95
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• 2017

This study examined the magnitude and distribution of earth pressure on the excavation wall in jointed rock mass by considering different groundwater conditions under various rock types, joint inclination angles, and earth pressure coefficients. Based on a physical model test (Son and Park, 2014), extended studies were conducted considering rock-structure interactions based on the discrete element method, which can consider the joints characteristics of rock mass. The results showed that the earth pressure was highly influenced by the groundwater condition as well as the rock type, joint inclination angle, and earth pressure coefficient. The results were also compared with Peck's earth pressure for soil ground, and clearly showed that the earth pressure in jointed rock mass can be greatly different from that in soil ground.