• 보존과학연구
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• s.31
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• pp.69-77
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• 2010

Preservation of artifacts that are excavated from archeological sites is closely related to soil environment. Biological remains are especially influenced by degradation activity of microorganism from soil environment. In this study a preserved human bone in archaeological tomb, Tou-kwang-myo from Joseon Period was analyzed to characterize bacteria groups by molecular genetic tools using 16S rDNA sequences. 117 clones were identified and classified 9 phylogenetic groups : ${\alpha}$-, ${\beta}$-, ${\gamma}$-, ${\delta}$-Proteobacteria, Sphingobacteria, Clostridia, Actinobacteridae, Nitrospiraceae, and Gemmatimonadetes according to homologous 16S rDNA sequences submitted in NCBI. ${\gamma}$-Proteobacteria group appears the highest ratio in bones (about 35%) while about 19.6% belong to the Actinobacteria group. The results may contribute to study on the effect of microorganisms on the human remains with burial method.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.665-672
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• 2002

In order to expand agricultural lands in the western and southern coasts of Korean Peninsula, coarse soils excavated from hillsides have been used as fill materials for reclamation. In order to tackle with the problems and to confirm availability, research on soil improvement involve mixing cement to the fine wet soils. Required undrained shear strength(c$\sub$u/) for fill material was analyzed to be 0.34∼1.2kg/$\textrm{cm}^2$. It has been known that when cement is added to high water content marine clay, its unconfined compression strength increased to 2kg/$\textrm{cm}^2$. Consolidation results show that pre-consolidation pressure increased to 1.8kg/$\textrm{cm}^2$ and 3.4kg/$\textrm{cm}^2$ with the addition of 3% and 5% of cement respectively. This result shows that low-height embankments could be constructed without significant compression. Since the effectiveness of improvement may be different site by site, the mix design for each site is necessary in order to optimize it. The process is first to determine aimed shear strength and then optimum mix ratio of cement after carrying out a series of tests.

• Geotechnical Engineering
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• v.11 no.4
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• pp.49-62
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• 1995

Soil nailing has been widely rosed during the last two decades to stabilize sheep excavated slopes in several countries. In thin study, the discrete element method has been applied to evaluate the stability of the reiuorced slope. This method is capable of not only estimat ins tensile and sheer stresses mobilized in nails but also providing individual safety factors of soil and nails, It has been assumed that the nailed slope be comprised of slices connected with elastoplastic twinkler springs. A reasonable mechanism is applied for representing the behavior between nails and adj scent soils. Taking into account for the bequence of construction the developed method well predicts the measured tensile forces developed in nails so that it is possible to appropriately evaluate the overall safety factor.

• Geomechanics and Engineering
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• v.34 no.3
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• pp.329-339
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• 2023

The objective of this study is to develop a Stability Evaluation System for retaining walls to assess their safety in real-time during excavation. A ground investigation is typically conducted before construction to gather information about the soil properties and predict wall stability. However, these properties may not accurately reflect the actual ground being excavated. To address this issue, the study employed a differential evolution algorithm to estimate the soil parameters of the actual ground. The estimated results were then used as input for an artificial neural network to evaluate the stability of the retaining walls. The study achieved an average accuracy of over 90% in predicting differential settlement, wall displacement, anchor force, and structural stability of the retaining walls. If implemented at actual excavation sites, this approach would enable real-time prediction of wall stability and facilitate effective safety management. Overall, the developed Stability Evaluation System offers a promising solution for ensuring the stability of retaining walls during construction. By incorporating real-time soil parameter analysis, it enhances the accuracy of stability predictions and contributes to proactive safety management in excavation projects.

• Conservation Science in Museum
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• v.22
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• pp.53-68
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• 2019

Two lime-soil mixture barrier tombs were excavated from the tomb complex of the Woo Family of the Danyang Wu clan dating to the Joseon dynasty in Godeung-dong, Seongnam-si, Gyeonggi-do. Relevant records offer information for more precisely dating these tombs and identifying their occupants. Tomb No. 4, in which a married couple was interred, has a corbeled square ceiling and inscriptions and paintings on its outer walls. The conservation treatment and an infrared inspection revealed that they were intended to express mourning. Tomb No. 6 has a corbeled rectangular ceiling and a single individual interred within. As the basic structure of the tomb was partially damaged in the process of disassembling it while moving the burial site, it was planned to exhibit the tomb outdoors after the remains and relics are collected. However, as the conservation treatment revealed the presence of funeral fans and pitch, and since the remaining structure clearly demonstrates the features of lime-soil mixture barrier tombs from the Joseon dynasty, the plan was changed following a meeting of an advisory council that decided in favor of presenting the tomb indoors. According to the analysis, the pitch is assumed to be resin of a rather low purity due to the immixture of foreign substances. The two tombs are expected to serve as important materials for related research, such as changes by period in the forms of Joseon-era tombs.

• Korean Journal of Heritage: History & Science
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• v.45 no.4
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• pp.114-125
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• 2012

The purpose of this study is to analysis chromaticity, granulometry, main chemical composition and mineral crystal structure of wall soils excavated from Poongnatoseong Earthen Castle using color reader, XRD, particla size analyzer. The analysed soils of Poongnatoseong Earthen Castle were yellowish brown and isabella. All samples were sands or sands including silty soil(SW~SC) and showed similar granulometry, chemical composition and mineral crystal structure, which were characteristics of construction materials suitable for modern road or airstrip. As resulting in comparison with 4 factors from chromaticity, granulometry, main chemical composition and mineral crystal structure, we decided that the control soils(PNS) near by Poongnatoseong Earthen Castle were not to be used for the castle wall construction We presumed that there was a huge soil distribution area for the wall construction around Poongnatoseong Earthen Castle. For further study, we will make a comparison analysis all kinds of soil characteristics. And then we can understand correctly about wall soils producing area, construction method, repair method and time of Poongnatoseong Earthen Castle.

• Korean Journal of Heritage: History & Science
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• v.45 no.3
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• pp.194-211
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• 2012

Pung-nap mudcastle has brought wide attention to archaeologists since scientific studies were carried out on the various types of building sites and excavated potteries related to A period of Baekje Kindom when it sat Hansung as the capital. It is identified that clay from Ra-No.19 site of Pung-Nap mudcastle has different from compositions that of residential soil. From archaeological point of view, it is believed that the the soil was a source material for potteries due to the appropriate viscosity and inclusions. Mineralogical and geochemical studies show that the compositions between the source material and randomly chosen two potteries from the same site are similar. Behavior pattern classification of major, trace and rare elements provides also very similar result. Artificial specimen has been made at different temperature in order to estimate firing temperature of the potteries by means of various kinds of instrumental application. As a result of the study, it is believed that the firing temperature of the red and brown pottery was $550{\sim}600^{\circ}C$ and $900{\sim}1,000^{\circ}C$ respectively.

• Journal of Soil and Groundwater Environment
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• v.18 no.2
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• pp.36-44
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• 2013

The objectives of this study were to identify the characteristics of shallow groundwater from the oil-contaminated site for a long period and to evaluate the applicability of biopile technology to treat the soil excavated from it. The eight monitoring wells were installed in the contaminated site and pH, Electrical Conductivity (EC), Dissolved Oxygen (DO), Oxidation Reduction Potential (ORP), Temperature and the concentrations of major ions and pollutants were measured. The VOCs in soil gas were monitored during biopile operation and TPH concentration was analyzed at the termination of the experiment. The pH was 6.62 considered subacid and EC was 886.19 ${\mu}S/cm$. DO was measured to be 2.06 mg/L showing the similar characteristic of deep groundwater. ORP was 119.02 mV indicating oxidation state. The temperature of groundwater was measured to be $16.97^{\circ}C$. The piper diagram showed that groundwater was classified as Ca-$HCO_3$ type considered deep groundwater. The ground water concentration for TPH, Benzene, Toluene, Xylene of the first round was slightly higher than that of the second round. The concentration of carbon dioxide of soil gas was increased to 1.3% and the concentration of VOCs was completely eliminated after the 40 days. The TPH concentration showed 98% remediation efficiency after the 90 days biopile operation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6C
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• pp.385-393
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• 2006

Soil nailing is a reinforcement method used for stabilizing excavated walls or slopes. Due to its much advantages such as ease of construction and economical efficiency, use of soil nailing is increased. However, the soil nail has much disadvantages for use in urban area. The soil nail needs to be installed inevitably beyond private land boundary, which causes rent for use. For this reason, removable soil nailing system was developed. However, the removal rate of this system is just about 50￠¦70%. To resolve this problem, the Fiber Reinforced Plastic (FRP) soil nailing system which does not need to be removed and allows for the installation beyond private land, is developed. In this paper, through theoretical and experimental studies in laboratory and field such as prototype tests, pullout tests, we evaluate the stability and behavior characteristics of the FRP soil nailing system. And, numerical analyses using FLAC2D were performed with respect to various soil conditions, where prototype test for excavation wall and pullout tests were carried out. As a result of this study, the FRP soil nailing systems show similar behavior characteristics with those of removable soil nailing system. Finally, considering the serviceability and mechanical stability of FRP soil nailing systems, it is enough to be used as a good alternative of general soil nailing system.

• Journal of the Korean GEO-environmental Society
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• v.19 no.4
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• pp.27-32
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• 2018

There were many ground excavation projects from past to present to make effective use of the limited land. And it is very important to predict the ground behavior depending on construction stage for ground excavation. Excavation of the ground involves changes in the stress and displacement of the ground around the excavated surface. Thus it affects the stability of the adjacent structure as well as the excavated surface. Therefore, it is very important to predict the ground behavior and stability of adjacent structure. And nowadays, numerical analysis methods are most often used to predict the effects of ground excavation. Recent, improvements of numerical analysis programs, along with improved computer performance, have helped solve complicated ground problems. However, except some specialized numerical analysis, most numerical analysis often predicts larger excavation floor displacement than field data due to adopt the Mohr-Coulomb analysis model. As a result, it raise the problem that increasing the amount of support on ground and structure. In this study, ground behavior analysis depending on analysis model (Mohr-Coulomb, Duncan-Chang, Modified Mohr-Coulomb and Hardening Soil model) has been carried out through the numerical analysis. When numerical analysis is carried out, this study is expected to be used as a basic data for adopting a suitable analysis model in various ground excavation project.