• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.521-527
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• 2005

In the past decades, complain about ground vibration and noise induced by pile driving has been quickly increased. Because of that, auger drilled piling methods have frequently used specially in urban area. However, the present auger drilled piling methods induce inevitable ground disturbance as well as a certain degree of vibration and noise due to the final hammering. For these reasons, a new auger drilled piling method is required to be developed. This paper introduces PDT(Pulse Discharge Technology) piling method and presents the characteristics of bearing capacity. The PDT piling method is to install in-situ piles using electric power so called Pulse. The pile installed by PDT appears to be able to develop shaft and end bearing capacity efficiently.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1203-1208
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• 2007

In the past decades, complain about ground vibration and noise induced by pile driving has been quickly increased. Because of that, auger drilled piling methods have frequently used specially in urban area. However, the present auger drilled piling methods induce inevitable ground disturbance as well as a certain degree of vibration and noise due to the final hammering. For these reasons, a new auger drilled piling method is required to be developed. This paper introduces PDT(Pulse Discharge Technology) piling method and presents the characteristics of bearing capacity. The PDT piling method is to install in-situ piles using electric power so called Pulse. The pile installed by PDT appears to be able to develop shaft and end bearing capacity efficiently. This paper introduces PDT(Pulse Discharge Technology) piling method, which is the 512nd new construction technology. The PDT piling method is to install in-situ piles using electrical power so called Pulse power. The pulse power is physical value that indicates the energy change per unit time(dE/dt). Since the pulse power is to push ground, using the pulse power is enable a hole to be expanded as well as the ground to be improved by compaction. Therefore, The pile installed by PDT appears to be able to develop shaft and end bearing capacity efficiently. In this study, couples of pile loading tests were carried out to figure out whether or not the PDT piling method is applicable to constructions like rail road facility. As a result, it was concluded that the PDT piling technique meet the requirements for such a rail road related construction.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.317-322
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• 2004

As a construction project in urban area tends to be high-rise and huge, the importance of the project's underground work, in terms of the cost and the schedule, is gradually increasing. It's extremely significant to choose a proper filing method, at the stage of underground work. However, in piling work many change orders have been occurred since a piling method is experientially selected based on uncertain information and many earth factors to consider. It has effects on the cost and the schedule of the project. In this study, we have suggested a decision model for piling method that can be used to determine and verify the suitable piling method in design and pre-construction phase of a project. Based on historical data, a neural network model has already proven to be efficient. The tests of the model for selecting a suitable piling method have progressed exactly with the data of 150 piling works which were done room 2000 to 2004 in Korea. The optimization or the developed neural network model has progressed with the data for teaming. The validity of the neural network model has been verified.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.231-238
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• 2000

Sand piling method is one of the most widely used methods to improve soft soils. There are several methods to install sand piles, but driven pile method is considered as one of the easiest method. This method simply pushes down the sand piles into soft soils, so that the excess pore pressure would be generated if the soil is saturated. This pore pressure acts as consolidation load. If the amount of sand pile induced pore pressure can be predicted in reasonable ways, the effects of sand piling to improve soft soils would be predicted, and the height of preload can be reduced. In this article, sand pile induced excess pressure was predicted by cavity expansion theory, and the predicted values were compared with the field measured values. The results showed fair agreements between the measured and the predicted excess pore pressure.

• Proceedings of the Korean Geotechical Society Conference
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• 1995.10a
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• pp.1031-1040
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• 1995

Recently, a more strict regulation has become effective on ground vibration and noise induced by construction activities. Consequently the demand for the most widely used method of installing precast piles, i.e. driven piles, is declining. At the same time the demand for low noise and low vibration piling method increased sharply. Currently there are several different low noise and low vibration methods of installing precast piles, mostly preboring method. However, the actual level of ground vibration and noise of these method of construction has not yet been clearly understood. In this paper, through field measurement, suggestion has been made to meet the requirements of the revised regulation.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.35 no.3
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• pp.57-66
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• 2023

In order to understand the economic feasibility of an offshore wind farm, this paper analyzed the differences in LCOE (levelized cost of energy) according to the support type and construction method of the substructure in terms of LCOE and sensitivity analysis was conducted according to the main components of LCOE. As for the site to be studied, the Southwest Offshore Wind Farm was selected, and the capital expenditures were calculated according to the size of the offshore wind farm and the installation unit. As a result of the sensitivity analysis, major components showed high sensitivity to availability, turbine related cost, weighted average cost of capital and balance of system related cost. Moreover, the post-piling jacket method, which was representatively applied to the substructure of the offshore wind farm in Korea, was selected as a basic plan to calculate the capital expenditures, and then the capital expenditures of the pre-piling jacket method and the tripod method were calculated and compared. As a result of analyzing the LCOE, it was confirmed that the pre-piling jacket method of the supporting structure lowers the LCOE and improves economic feasibility as the installation number of turbines increases.

• Geotechnical Engineering
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• v.13 no.4
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• pp.25-36
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• 1997

To increase the bearing capacity of existing auger-drilled piles and decrease the noise and vibration during the installation of the piles, Spirally-reamed and Under-reamed auger trilled piling methods were developed. Field tests were performed to verify the inurement degree of bearing capacity and the constructional possibility of the new augerdrilled piling methods. The test results showed that the bearing capacity of the new augertrilled piles was fairly improved by the grooves of piles, and the skin friction was affected by the groove height and spacing between grooves. It was found that the skin friction takes the great part of total bearing capacity in auger drilled Biles, i.e. 74~80% in case of the existing methods and 81~86% in case of these methods. Moreover, the settlement of spirally-reamed and under reamed piles was smaller than that of the existing augerdrilled pile for the same loading state.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.559-566
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• 2008

This paper describes the state-of-the-art and -practice of embedded precast pile methods in Korea. The current status of embedded precast piling was reviewed in terms of its design, construction and quality assurance available for last decade in Korea. Based on the results obtained, some suggestions and authors' experience were proposed to design and construct the embedded precast pile foundations.

• Journal of the Korean Society of Costume
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• v.59 no.5
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• pp.41-52
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• 2009

In contemporary art, soft materials are used in various forms and ways as a medium expressing contingency beyond a simple nature of materials. In the late 1960's, the appearance of soft sculpture as a refusal of the stereotyped 'Erection' characteristic of traditional sculpture served as an opportunity for more attention to soft materials. Fashion is the reflection of age, and the mirror of society, culture and arts. In other words, soft sculpture and fashion are artistic behaviors in the same context, which have neither been fixed nor erected. This study finds its significance in analyzing correlation between soft sculpture and fashion, and the importance of contingency as artistic expression means in this age when boundaries between genres are obscure, and artistic values are given to fashion. By doing so, it aims to present the direction toward which fashion should face in the future, establishing a new aesthetic consciousness with which more creative and various expressions are available in fashion as well. This study presented as its theoretical background the concept of soft sculpture affected by Marcel Duchamp among representative examples of the contingency that started to appear in art starting in the early 20th century. It also analyzed the soft sculpture appeared in 1960s and the expression methods and features of contingency appeared in fashion after late 1990s through a new approach of piling up, hanging up, and tying, three categories classified by Maurice $Fr{\acute{e}}churet$. Common features of the contingency expressed in soft sculpture and fashion were derived in the analysis, which are intensive effects of energy, values given to physical properties themselves, and esthetics of anti-form.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.519-526
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• 2010

The construction site for $\bigcirc\bigcirc$ transformer substation was located at a mountain valley. In order to prepare the site, the valley was first filled with crushed rock debris up to 63m. Since the main concern of this project is to minimize differential settlement of the foundation of transformer facilities, dynamic compaction was performed every 7m followed by reinforcement with EMP(Ez-Mud Piling). The EMP is one of bored piling methods, in which a hole is bored by means of air percussion and maintain by injecting Ez-Mud. Then a PHC pile (Pretensioned spun High strength Concrete pile) is embedded and finalized with a hammer. In this study, bearing capacities and long term behavior of a pile installed by EMP were investigated. To achieve these objectives, a series of tests such as static and dynamic load tests were conducted. In addition, a construction quality control standard was proposed based on the test results.