• 기술발표회
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• s.2006
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• pp.35-44
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• 2006

Supporting method of a Temporary retaining wall for underground excavation project are adopted by systems of strut, anchor, nail, raker, etc. Strut system and Raker system of these methods are mostly used preloading jack to minimize deformations of retaining wall. We determinate efficient preloading to analysis these strut-preloadings, deformations of retaining wall, axial forces, and etc.. This study is analysed that preloading applied 0%, 10%, 20%, 30%, ...., 100% for strut and raker installed by CIP temporary retaining wall. This study results that adequate preloadings were determined to analysis correlations of preloading, deformations of wall, maximum bending moment, axial force of strut, and displacement of surrounding.

• Journal of the Korean Geotechnical Society
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• v.16 no.2
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• pp.5-12
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• 2000

The hazard of excavation may be very high until a supporting system is completely installed. In this paper, an excavation method which uses partially reinforced soldier pile($\square$-shape) inserted by a short length steel bar was proposed and simulated by the finite element method. The reinforcing steel bar is moved down along the stage of excavation to reinforce the stiffness of the supporting system. The result of analysis showed that the risk of failure by bending moment or shear stress could be significantly reduced by the reinforcing effect of the steel bar. The proposed method could be applied to the strut-supporting wall or the diaphragm wall.

• 한국전산유체공학회:학술대회논문집
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• 2003.08a
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• pp.102-105
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• 2003

The effect of the external balance strut on the wind tunnel model is investigated with simplified geometries. For this study, flat plate and elliptic wing are simulated with and without a cylinder. Pressure and wall shear stress distribution are analyzed to understand the effect of the cylinder.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.248-259
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• 2010

In the case of relatively good ground and construction condition in the deep excavation for the construction of subway, railway, building etc., flexible earth retaining systems are often used in an economical point of view. It is generally known that the mechanism of behavior in the flexible earth retaining system is relatively more complicated than the rigid earth retaining system. Moreover in the case of long span strut supporting system the analysis of strut axial force change becomes more difficult when the differences of ground condition and excavation work progress on both sides of excavation section are added. When deeper excavation than the specification or installation delay of supporting system is done or change of ground condition is faced due to the construction conditions during construction process, lots of axial force can be induced in some struts and that can threaten the safety of construction. This paper introduces one example of long span deep excavation where struts and rock bolts were used as a supporting system with flexible wall structure. The characteristics of ground deformation and strut axial force change, the measured data obtained during construction process, were analysed, the effects of relatively deeper excavation than the specification on one excavation side and rapid drawdown of ground water level on the other excavation side were deeply investigated from the viewpoint of mutual influences between ground deformations of both excavation sides and strut axial force changes. The effort of this article aims to improve and develop the technique of design and construction in the coming 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.308-319
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• 2009

In the case of relatively good ground and construction condition in the deep excavation for the construction of subway, railway, building etc., flexible earth retaining systems are often used in an economical point of view. It is generally known that the mechanism of behavior in the flexible earth retaining system is relatively more complicated than the rigid earth retaining system. Moreover in the case of long span strut supporting system the analysis of strut axial force change becomes more difficult when the differences of ground condition and excavation work progress on both sides of excavation section are added. When deeper excavation than the specification or installation delay of supporting system is done or change of ground condition is faced due to the construction conditions during construction process, lots of axial force can be induced in some struts and that can threaten the safety of construction. This paper introduces two examples of long span deep excavation where struts and rock bolts were used as a supporting system with flexible wall structure. And the sections of two examples are 50 meters apart in one construction site, they have almost similar design and construction conditions. The characteristics of ground deformation and strut axial force change were analysed, the similarity and difference between measurement results of tow examples were compared and investigated. The effort of this article aims to improve and develop the technique of design and construction in the coming projects having similar ground condition and supporting method.

• Journal of the Korean Geotechnical Society
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• v.26 no.7
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• pp.171-186
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• 2010

It is generally known that the mechanism of behavior in the flexible earth retaining system is relatively more complicated than in the rigid earth retaining system. Moreover in the case of long span strut supporting system the analysis of strut axial force change becomes more difficult when the differences of ground condition and excavation work progress on both sides of excavation section are added. When deeper excavation than the specification or installation delay of supporting system or change of ground condition happen during construction process, lots of axial force can be induced in some struts, which threaten the safety of construction. This paper introduces two examples of long span deep excavation where struts and rock bolts were used as a supporting system with flexible wall structure. The characteristics of ground deformation and strut axial force change, which were measured in the sections of two examples that are 50 meters apart in one construction site and have almost similar design and construction conditions were analysed, the similarity and difference between measurement results of two examples were compared and investigated. This article aims to improve and develop the technique of design and construction in future projects having similar ground condition and supporting method.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.19-20
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• 2012

According to develop urban area, the depth and floor area of basement tend to become deeper and larger. Excavation work for basement floor work is very important because its cost take 20% of total construction cost. Therefore, many studies of developing retaining wall system have performed for feasibility and safety in deep excavation work. In this study, new supporting system used high-strength pipe for retaining wall is introduced to reduce the construction cost and improve the safety and constructability by analyzing case study.

• Journal of Chest Surgery
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• v.23 no.5
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• pp.1027-1034
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• 1990

Pectus excavatum, commonest developmental anomaly of chest wall, is manifested by depression of the sternum and lower costal cartilages that is of surgical interest. From 1982 through 1990, fifteen patients have undergone surgery for treatment of pectus excavatum and treated by Ravitch operation: 5, Modified Ravitch operation; 4, Wada operation, 1 and Modified Wada operation, 5. There was familial history of pectus excavatum in 3 patients. Associated congenital anomaly were seen in 6 patients; scoliosis in 3 patients, right inguinal hernia in 1, polydactyly in 1 and patent ductus arteriosus in 1 patent. Postoperative minor complications were developed in 3 cases; pneumothorax, 2 cases; pleural effusion, 2 cases; wound infection and dehiscence, 1 cases; pressure sore due to strut malposition, 2 cases; flail chest and 2 cases; seroma. The incidence of the postoperative complications were more common in cases who were treated by metal strut, pin or other prosthetic materials for supporting the chest wall integrity than the standard corrective procedure. All cases have no recurrence of chest wall depression and operative death.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1496-1503
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• 2005

The study on the lateral earth pressure is briskly preformed for various conditions such as type of retaining walls, ground condition, and type of supporting systems. It is not simple to determine the distribution of lateral earth pressure accurately, however, because the lateral earth pressure is affected by various factors. This study is performed to analyze the behavior of earth retaining walls for new excavation contacting with existing excavation by comparing with the site measuring values before and after new excavation. On the base of observation, the distribution of strut axial forces is similar to that of ganeral earth retaining walls, but strut axial forces is increased by removal of existing earth anchors. When new excavation is performed contacting with existing excavation, the axial force of strut is decreased because of soil exclusion in the behind walls, but that force is increased after new exeavation. The analysis result show that the installation of strut in middle part makes a effect to not only 1 adjacent strut, but 3-5 adjacent struts. Also during new excavation strut axial forces is decreased by relaxation of total earth retaining wall system.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.581-582
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• 2009

Continuous deep girders which transmit the gravity load from the upper wall to lower columns have frequently long end shear spans between the boundary of the upper wall and the face of the lower column. This paper presents the results of tests and analyses performed on three 1:2.5 scale specimens with long end shear spans, (the ratios of shear-span/height : 2.0