• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1461-1467
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• 2005

In this study, a new earth retention system has been developed and introduced. This system is a self-supported earth retaining wall without struts. The new earth retention system consists of connected double H-pile and wale. This system provides a larger spacing of support, economical benefit, construction easiness, good performance and safety. This paper explains basic principles and mechanism of self-supported earth retaining wall. In order to investigate applicability and safety of this system, numerical analysis was performed. The finite differential method program, FLAC3D is used. The predicted performances of this system were presented and discussed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.385-392
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• 2021

In general, earth retaining work in construction works enables the construction of structures, prevents the displacement of the surrounding ground to the maximum extent, and plays an important role in ensuring the safety of the surrounding structures and field workers. The earth retaining work and the construction method differ according to the various ground characteristics, surrounding topographical characteristics, repair environment, and design conditions. In particular, in the case of Seoul city, the environments and ground conditions differ according to the area. This study analyzed the earth retaining work cost mainly for the apartment construction project in Seoul and calculated the approximate earth retaining work cost at the project planning stage. A model was developed to predict the cost of earth retaining work that matches the characteristics of Seoul City and predict the construction cost for earth retaining work. This paper presents the predicted earth retaining work cost using a multiple regression model that applies 10 project outlines as independent variables. The error rate of the prediction result of the earth retaining work cost of the apartment construction project in Seoul using multiple regression models was 10.75%.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1073-1074
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• 2006

In this paper, we perform a simulation to verify the earth resistance values in Common Earth Network. The simulation is performed on the assumption that certain shorts are occurred in common earth network. Furthermore, from the result, we confirmed that very small earth resistance values in common earth network are given, by carrying out practical measurements in railway sections where common earth network is composed. From the effect, we could discover that the construction of common earth network is in a disadvantageous position on the financial aspect, while it is the most desirable way of construction for the purpose of Earth.

• Journal of the Korean Society of Safety
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• v.23 no.1
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• pp.28-34
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• 2008

The corrugated steel plate structures is applied to the construction of mountain tunnel portal part with shallow depth, the tunnel on the outskirts of urban areas and ecology move passage. In this study, A finite element method is used for research the behavior of corrugated steel plate structures due to construction position under declinating earth pressure and excavation depth. A finite element method were performed varying construction position(10, 15, 20 and 25m) from slope and excavation depth from surface. The hoop thrust and moment, displacement of corrugated steel plate subjected to construction position and excavation depth is determined from a finite element method. From results of finite element method, it was found that the increase of thrust and the decrease of displacement as the amount of distance increase from slope with construction position. But the thrust and moment, displacement has not different value with excavation depth.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.196-197
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• 2021

The underground method can be divided into Top-Down, Semi-Top-Down, Up-Up and Down-Up methods according to the construction order of the upper and lower structures. Among them, the Down-Up method proceeds with the construction of the first floor and its lower floors, and when the foundation is completed, the vertical members of the basement are sequentially completed from the foundation and the above-ground floor is constructed. In this paper, the crack reduction method around the open section of the Down-Up method affected by earth pressure was analyzed and divided into design and construction parts.

• KIEAE Journal
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• v.7 no.6
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• pp.91-97
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• 2007

This research examines the characteristics of the "rammed earth form" based on the criteria for the selection of forms. For this purpose, the paper first reviews the characteristics and orientation of the earth-construction and looks into the outline, the prerequisite, the current status and the tendency of the rammed earth form system through previous studies. Consequently, we aims to contribute to the criteria for the selection of rammed earth forms in the future through a comparative analysis of the construction cost, quality, safety and easiness of works between the veneer board form and the euroform, which are most widely used at earth housing project in the domestic country. The results reveals that the euroform is better than the veneer board with 21% of total cost in the cost analysis. But this better than that in the side of easiness of construction. In both cases, the buckling of wall panel form and the labor-oriented characteristics of the methods are the future research issues in the rammed earth form system.

• Korean Journal of Construction Engineering and Management
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• v.17 no.3
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• pp.116-124
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• 2016

Work efficiency of earth work which is one of the main works occurring in construction site mainly depends on the performance of individual operators of earth work equipment. Consequently, the skill of individual operators of earth work equipment can significantly affect overall construction schedules. Many invisible areas inevitably exist in construction site because of the nature of construction site where occlusions occur from structures being built, installed or moving equipment, moving workers, etc. The lack of visual information regarding tasks critically impedes the effective performance of operators of earth work equipment. AR (Augmented Reality) is a computer technology that superimposes virtual objects onto the real world scene. This characteristic of AR may address the lack of visual informations in earth work process, thus helping to improve the work efficiency of operators of earth work equipment. The purpose of this study is to present a task-visual information map that identifies visual informations required in tasks of earth work and which of the tasks are suitable for AR technology. This study focuses on visual informations in tasks of earth work with excavators. The map was created based on the investigations on the problems of each task of earth work with excavators and visual informations required to address the problems. Through the map, four visual informations were found to be suitable for AR technology to improve the work efficiency of excavator operators. Based on the findings of this study, AR systems for excavators can be developed more effectively.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.77-84
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• 2003

Deep excavations in the urban areas have been frequently going on in large scale. Soil-nailing and Earth-anchor supporting methods are generally used in deep excavation. These construction methods cause ground disturbances during drilling process, and damages of adjacent structures and ground due to the differential settlement throughout construction period, and unexpected behaviors of supporting system according to the characteristics of drilling machine and ground condition. This article introduces two actual examples of adjacent deep excavation for the construction of university buildings in granitic Seoul area. The important results of construction and measurements obtained using Crawler drilling machine for Soil-nailing and Earth-anchor supporting methods are summarized. And some suggestions are given to improve and develop the technique of design and construction in the deep excavation projects having similar ground condition and supporting method.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.571-578
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• 2009

Recently, micropiling techniques are increasingly applied in foundation rehabilitation/underpinning and seismic retrofitting projects where working space provides the limited access for conventional piling methods. Micropiling techniques provide environmental-friendly methods for minimizing disturbance to adjacent structures, ground, and the environment. Its installation is possible in restrictive area and general ground conditions. The cardinal features that the installation procedures cause minimal vibration and noise and require very low ceiling height make the micropiling methods to be commonly used for underpin existing structures. In the design point of view, the current practice obligates the bearing capacity of micropile to be obtained from skin friction of only rock-socketing area, in which it implies the frictional resistance of upper soil layer is ignored in the design process. In this paper, a new micropiling method and its verification studies via field installation are presented. The new method provides a specific way to grout bore-hole to increase frictional resistance between surrounding soil and pile-structure and it allows to consider the skin friction of micropiles for upper soil layer during design process.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.660-670
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• 2009

Neighboring construction becomes mainstream of Ground excavation in downtown area. This causes the displacement, deformation, stress condition, etc of the ground surroundings. Therefore Neighboring construction have an effect on Neighboring structure. All these years a lot of Neighboring construction carried out, and the accumulation of technology also get accomplished. But earth retaining structure collapse happens yet. Types of earth retaining structure collapse are 12. 1. Failure of anchor or strut system, 2. Insufficiency of penetration, 3. H-pile Failure on excessive bending moment, 4. Slope sliding failure, 5. Excessive settlement of the back, 6. Deflection of H-pile, 7. Joint failure of coupled H-pile, 8. Rock failure when H-pile penetration is rock mass, 9. Plane arrangement of support systems are mechanically weak, 10. Boiling, 11. Heaving, 12. Over excavation. But field collapses are difficult for classification according to the type, because collapse process are complex with various types. When we consider the 12 collapse field, insufficient recognition of ground condition is 4 case. Thorough construction management prevents from fault construction. For limitations of soil survey, It is difficult to estimate ground condition exactly. Therefore, it should estimate the safety of earth retaining system, plan for necessary reinforcement, according to measurement and observation continuously.