• Proceedings of the Korean Geotechical Society Conference
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• 1996.03a
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• pp.65-86
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• 1996

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2C
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• pp.65-74
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• 2011

This paper presents an analysis of excavation behavior of an earth retaining wall supported by large diameter soil-cement blocks at a field trial site. The concept and design philosophy of the large soil-cement block reinforcement are described first. The wall behavior during sequential excavations up to 9.8 m is analyzed based on the measured lateral wall movements and earth pressures. The settlements of adjacent ground are examined by field measurements and inverse numerical analysis. The results indicate that, when the lengths of the soil-cement blocks were over 0.45 H (H: wall height), the displacements and the earth pressures induced by the excavations were similar to those supported by conventional methods such as soil nailing.

• Journal of the Korean GEO-environmental Society
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• v.10 no.3
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• pp.63-71
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• 2009

The movement of in-situ walls has become very important as construction in large cities moves upward, instead of outward. Tall structures typically have deep excavations not on1y to provide extra space for parking, but also to reduce the potential settlement of the building. These large excavations require a robust bracing system to resist the lateral earth pressures as the depth increases. Methods to predict deflections of the retaining systems are of utmost importance because wall movements allow potentia1 settlement of adjacent structures. Case studies will be analyzed and measured waI1 def1ections will be compared with predictions from empirica1ly derived charts.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1294-1300
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• 2009

Recently, excavations in highly congest urban area have been increased. For the excavations conducted in extremely narrow spaces, we have been developing a novel soil reinforcement system of temporary retaining walls by using deep cement mixing method. The developing method installs largerdiameter ($\Phi$=300~500mm) and shorter reinforcement blocks than previous reinforcement system for mobilizing friction with soils, therefore it has advantages of not only shortening the length of reinforcement system but also reducing the amount of reinforcement. In this study, we performed a numerical analysis of the new reinforcement system by using a commercial finite element program, and evaluated the behavior of the reinforced retaining wall system under various conditions of the length, the diameter, the spacing, and the angle of the reinforcement system.

• Geomechanics and Engineering
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• v.28 no.3
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• pp.313-324
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• 2022

Rock properties are important in the design of mines and civil engineering excavations to prevent the imminent failure of slopes and collapse of underground excavations. However, the time, cost, and expertise required to perform experiments to determine those properties are high. Therefore, empirical models have been developed for estimating the mechanical properties of rock that are difficult to determine experimentally from properties that are less difficult to measure. However, the inherent variability in rock properties makes the accurate performance of the empirical models unrealistic and therefore necessitate the use of soft computing models. In this study, Gaussian process regression (GPR), artificial neural network (ANN) and response surface method (RSM) have been proposed to predict the static and dynamic rock properties from the P-wave and rock density. The outcome of the study showed that GPR produced more accurate results than the ANN and RSM models. GPR gave the correlation coefficient of above 99% for all the three properties predicted and RMSE of less than 5. The detailed sensitivity analysis is also conducted using the RSM and the P-wave velocity is found to be the most influencing parameter in the rock mechanical properties predictions. The proposed models can give reasonable predictions of important mechanical properties of sedimentary rock.

• Journal of the Korean GEO-environmental Society
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• v.13 no.10
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• pp.77-83
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• 2012

Recently, excavations using propped walls were popularized in downtown due to reduced settlement of nearby structures. These excavations is induced strain to propped walls or settlement in near ground. In this study, the ground reinforcing effect was proven using NDS, which is an inorganic injection material. Injection tests were performed to compute optimum injection pressure and volume. Next, calibration chamber tests were performed by using computed injection pressure and volume, and wall behaviour was examined for overburden pressures of 50kPa and 150kPa. Ground reinforcing effect was shown when the material behind the propped wall was grouted. From test results, optimum injection pressure was 350kPa and the optimum volume was 10L considering economics. Calibration chamber test results show that after the material was grouted, the maximum settlement was reduced to 19% of the non-grouted condition. For overburden pressures of 50kPa and 150kPa behind the wall, the settlement of the wall increased by 58% and 57% when compared to the case of no overburden pressure.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.27-39
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• 2005

목적구조물의 건설을 위한 지반굴착시 지반거동에 대하여 보다 현실적이고 개념적으로 제시하여 정보화시공시 보다 안전시공을 위하여 지분굴착에 따른 지반거동에 대한 이해를 도모하고 신속한 문제해결 기술에 활용되도록 하였다. 굴착시에 대하여서는 개착 뿐만 아니라 터널의 굴착도 포함하여 지반거동을 이해하기위한 기본개념과 아울러 지반거동에 대한 정성적인 분석기법에 대하여서도 제시하였다.

• Journal of the Korea Furniture Society
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• v.12 no.2
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• pp.39-47
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• 2001

This study was carried out to identify wood species excavated at the temple site of Backjae dynasty in Neungsanri, Buyeo. At the temple site, there were great excavations such as Backjae Incense Burner(National Treasure No.287) and Stone Reliquary(National Treasure No.288). The King Chang 13 Year carved on Stone Reliquary indicated that this temple was completed in A.D 567. Identification of wood species were as follows: The Temple building was constructed by Pinus densiflora Sieb. et Zucc. The species of the main pillar of Wooden Pagoda which preserved relics of the Buddha was Zelkova serrate Makino.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.85-95
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• 2002

A substantial portion of the cost of deep excavations in urban environments is devoted to prevent ground movements and their effects on adjacent buildings and utilites. Prediction of ground movements and assessment of the risk of damage to adjacent structures has become an essential part of the planning, design, and construction of a deep excavation project in the urban environments. This paper presents damage assessment techniques for buildings and utilities adjacent deep excavation, which can be readily used in practice.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1301-1306
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• 2009

Recently, urban excavations are one of most frequent geotechnical work according to construction of a high rise building and subway. These kind of excavation affect to a adjacent ground or structure and it can trigger various severe accidents. Generally, the ground is closer to the excavation site, the deformation become larger. In this study, special ground settlement case due to adjacent ground excavation is presented and a cause of deformation is examined by various geotechnical exploration, lab-testing and numerical analysis.