• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.97-101
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• 2001

Recently, an excavated soil-recycling machine has been receiving considerable attentions. The mobile type excavated soil-recycling machine is able to improve the soils by adding the additives such as slaked lime and cement at the construction site. However, not only the mechanical factors such as paddle inclination angle and pitch of the paddle but also the physical properties of the excavated soils affect the mixing performance of the excavated soils and additives. In this sense, experimental investigations are uneconomical and ineffective. This paper concerns with the numerical simulator to analyze the mixing behavior of excavated soils and additives in the soil-recycling machine with dual shafts in order to assist the economical and effective design of the optimum soil-recycling machine. By using the simulator, several simulations were carried out, and the effects of some mechanical parameters such as the paddle inclination angle and pitch of the paddle on the mixing performance were made clear.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1757-1763
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• 2011

In recent years, accordance to industrial development project on railway investment, adverse environmental issues of the investment, such as disputed cases about recycling and usage of Ballast Cleaner excavated soil, have been continuously increasing. It will not only enhance the regulation of soil contamination but take considerable time and cost in future. In this study, we investigated soil contamination and burnability with soil of Chungang Line, Taebaek Line, Chungbuk Line, in order to seize a possibility of recycling Ballast Cleaner excavated soil for the natural materials and substantial heat sources, which are necessary resources for cement manufacturing process. As a result of this study, It is found that Ballast Cleaner excavated soil is satisfied with a standard. The excavated soil contains a lot of cement ingredients and fossil fuel dust incurred from freight transportation, so it is expected to use for ingredients of cement and replacement of heat sources.

• Journal of the Korean Society of Safety
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• v.36 no.5
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• pp.18-26
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• 2021

The effect of heavy construction equipment on the excavated slope is investigated by slope stability analysis. A mobile crane with 500 kN capacity is applied as a working load to the background surface of the excavated slope, in both sandy soil and clay, designed to guarantee the safety of slope stability. Major parameters such as the distance between the edge of the slope and the mobile crane, groundwater level, and ground plate size of the mobile crane are considered. Only 23.8% and 14.3% of the analysis models with sandy soil and clay excavated slope, respectively, satisfied the slope stability. By changing the slope of the sandy soil from 1:1.0 to 1:1.2, the number of analysis models securing slope stability increased from 23.8% to 40.5%. For the clay excavated slope, the analysis models securing slope stability increased from 14.3% to 42.9% by changing slope inclination from 1:0.8 to 1:1.2. In addition, it is found that the increase in the size of the ground plate of the mobile crane increases the analysis models that secure slope stability. Therefore, it is an effective way to relax the excavated slope's inclination angle and simultaneously increase the ground plate size to guarantee stability.

• Geotechnical Engineering
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• v.11 no.2
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• pp.79-98
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• 1995

In the present study an analytical modeling was carried out to predict mobilized shear strength at the interface between the nail and surrounding soils by carefully examining the behavior characteristics of nailed boil excavated walls. Based on the developed model of mobilized shear strength, the method of overall stability analysis of nailed -soil walls was also developed using the Morgentern -Price limit -equilibrium slice method. The developed analytical procedure could predict the behaviors of nailed -soil excavated walls during the successive excavation stages, at the final stage of construction and post -construction stages. To verify the validity of the developed model and method of stability analysis, mobilized tensile forces of nails and overal stability estimated by the developed procedure were compared with test measurements from three nailed -soil experimental walls having different soil conditions. The effect of seepage pressures inside the soil mass was considered in the developed procedure.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.6
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• pp.599-615
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• 2022

In order to excavate underground tunnel most safely such as Han river, the slurry shield TBM method is applied to cope with face of high water pressure for many metro projects. In downtown subway project most of excavated soil is discharged externally whereas in road construction excavated soil is used as filling materials so it becomes important factor for success of the project. After excavated soil, weathered rock and soft rock are discharged with bentonite through discharge pipe to slurry treatment plant then those soils are separated in separation plant according to those size. Fine grained soil has been discarded together with filter cake but it is not toxic and can be mixed with coarse aggregate in proper ratio so this study is performed to find use of qualified filling material to meet quality standard. Therefore, in this study, legal standards and quality standards for the utilization of excavated soil of the slurry shield TBM method were examined and test was conducted to derive recycling way for filter cake and aggregate. And a plan for using it as a filling material for road construction was derived. Because bentonite is a clay composed of montmorillonite, and the excavated soil in the tunnel is also non-toxic, disposal of this material can waste social cost so it is expected to be helpful in the underground space development project that carries out the TBM project by recycling it as a valuable resource.

• Korean Journal of Heritage: History & Science
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• v.43 no.3
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• pp.26-47
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• 2010

When the term conservation is used with regard to excavated features, it means not only conservation but also restoration. Restoring the features here does not imply restoring their original form but restoring their form at the moment of excavation. That means, the conservation of excavated features includes the concept of both reparation and restoration. The way of conserving excavated features can be largely categorized into on-site conservation and transfer conservation. On-site conservation means to conserve excavated features as they were at the excavation site. It can be further categorized into soil-covered on-site conservation, in which excavated features are covered with soil to prevent them from being damaged, and exposed on-site conservation in which the features were conserved as they were exposed. Transfer conservation is operated on the premise that excavated features are transferred to another place. It can be further categorized into original form transfer, transcribing transfer, reproduction transfer, and dismantlement transfer. Original form transfer refers to the method of moving the original forms of excavated features to another place. Transcribing transfer refers to moving some of the surfaces of excavated features to another place. Reproduction transfer refers to restoring the forms of excavated features in another place after copying the forms of excavated features at the excavation site. Dismantlement transfer refers to the method of restoring excavated features in a place other than the excavation site in the reverse order of dismantlement after dismantling the features at the excavation site. The most fundamental issue regarding conserving excavated features is the conservation of their original forms. However, the conservation of excavated features tends to be decided depending on a variety of conditions such as society, economy, culture, and local situations. In order to conserve excavated features more effectively, more detailed and specialized conservation methods should be created. Furthermore, continuing research is needed to find the most effective way of conserving them through exchange with other neighboring academic fields and scientific technology.

• Journal of Ocean Engineering and Technology
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• v.20 no.5 s.72
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• pp.49-56
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• 2006

In this thesis, centrifuge model experiments and numerical analyses were carried out to investigate the behavior of an excavated slope in soft clay ground. Centrifuge model tests were performed with various slopes for the excavated ground, such as 1:1.5 and 1:2. Pore pressuresthe model ground were measured to find their effects on the stability of the excavated slope. These experiments showed that the model with 1:2.5 maintained its stability within a short period of time and failed gradually. Therefore, anexcavated slope of soft soil with this slope might maintain stable conditions within a certain time. The mode1 with a 1:3 slope was observed to maintain a very stable condition, showing insignificant deformation in the ground after being excavated. Numerical analyses with PLAXIS, a commerciallyavailable software implemented with the finite element numerical technique, were performed to find the pore pressure distribution within the ground mass and the deformation of the soil. From the results of numerical analysis, a negative pore pressure was developed after the excavation and thus the stability of the slope was maintained. The safety factor for slope failure was found to decrease with time because of the dissipation of negative pore pressure with time.

• 보존과학연구
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• s.19
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• pp.109-132
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• 1998

According to excavation of Imdang site, these sites were excavated place to a various of sites from Early lron period to the Koryo Kingdom. Artifacts to be conserved were excavated from A, D and E district. Metal artifacts were excavated from D and E district and lacquer ware artifacts were excavated from Adistrict. Metal artifacts including lacquer ware iron sword, imitative bronze mirror, Osujen and bronze artifact with letter and so on. Bronze artifacts were covered with soil and rust and performed consolidation after passivation treatment with Benzotriazole solution. Also, iron artifacts performed desalting treatment with 0.1M sesquicarbonate solution. After desalinization, adhesive of these artifacts were processed with Araldite(rapid type) after consolidation with20%∼30% NAD-10 solution. Lacquer ware artifacts remained fragments of lacquer to be all corroded and soiled. Therefore these artifacts retained its original form. Fragments of lacquer joined with Caparol 1%∼3% solution and the soil of relics coated with PSNY 3%∼6% solution. There were many kinds of lacquer were. Lacquer ware artifacts presumed to a string instrument that provide important clues for lacquer ware research. As for lacquer fragments inquire, paints grain size were $2∼5\mum$ and conformed to vanished three times.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.4
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• pp.349-357
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• 2019

Controlled low strength material(CLSM) has been developed using variety of material such as excavated soil, industrial by-product and industrial waste. But theses research limited at laboratory test and failed at commercialization. So in this paper evaluates CLSM used excavated soil characteristics such as flowability, bleeding rate, early strength for following process and 28day strength for re-excavatability. Also, various mix proportion of CLSM by water-binder ratio and soil-binder ratio were evaluated in laboratory. And derive the optimized CLSM mix proportion for using at field application test by movable batch plant. After applying CLSM at trench, evaluate core sample strength and excavatability by shovel, pickax and excavator for verify re-excavation. Furthermore, measure the level change after casting CLSM to inspect subsidence stability. As results of these assessments, not only confirmed the characteristics of CLSM at field but the fillability around pipe and subsidence stability.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.5
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• pp.355-374
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• 2022

Soil conditioning improves the performance of EPB (earth pressure balance) shield TBMs (tunnel boring machines) by reducing shear strength, enhancing workability of the excavated soil, and supporting the tunnel face during EPB tunnelling. The mechanical and rheological behavior of the excavated muck mixed with additives should be properly evaluated to determine the optimal additive injection condition corresponding to each ground type. In this study, the laboratory pressurized vane test apparatus equipped with a vane-shaped rheometer was developed to reproduce the pressurized condition in the TBM chamber and quantitively evaluate rheological properties of the soil specimens. A series of the pressurized vane tests were performed for an artificial sand soil by changing foam injection ratio (FIR) and polymer injection ratio (PIR), which are the injection parameters of the foam and the polymer, respectively. In addition, the workability of the conditioned soil was evaluated through the slump test. The peak and yield stresses of the conditioned soil with respect to the injection parameters were evaluated through the rheogram, which was derived from the measured torque data in the pressurized vane test. As FIR increased or PIR decreased, the workability of the conditioned soil increased, and the maximum torque, peak stress, and yield stress decreased. The peak stress and yield stress of the specimen from the laboratory pressurized vane test correspond to the workability evaluated by the slump tests, which implies the applicability of the proposed test for evaluating the rheological properties of excavated soil.