• International conference on construction engineering and project management
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• 2009.05a
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• pp.218-223
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• 2009

During the process of excavation for substructures of buildings, precise and constant measurements of retaining wall displacement is crucial for construction to be complete and safe. Currently an inclinometer is used to measure displacement around the perimeter of an excavation site. The existing inclinometer system requires an instrument to be placed inside pre-bored holes for each measurement with an typical interval of two weeks. This makes it difficult to obtain continuous displacement data, especially during a critical time such as rainy season in summer. Also, the existing inclinometer is placed at certain distance away from the retaining wall system itself. Thus, exact measurement of retaining wall movement is compromised because of the distance between the retaining wall and the inclinometer. This paper presents the development of wireless inclinometer system for the displacement measurement of retaining walls by being attached directly to the retaining wall. The result of the application of the developed systems are provided with advanced ubiquitous sensor network (USN) system features. The USN technique incorporated into the system enables users to monitor movement data from wherever possible and convenient such as construction manager's office on site or any other places connected through internet. The research work presented in this paper will provide a basis to save construction time and cost by preventing safe-related unexpected delay of construction due to the failure or collapse of retaining walls.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.10a
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• pp.46-55
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• 2006

There are many kinds of braced cut wall methods as the sheet pile, SCW, CIP and slurry wall which is adoptable for a deep excavation construction in a coastal filled land. The braced cut wall which has a strong stiffness is very stable but it has the weak point that the construction cost is high. Thus when a braced cut wall is designed, the geotechnical engineers choose the braced cut wall which has more safe and economic in the consideration of surrounding buildings near the construction site. Especially, when the sheet pile method as a braced cut wall is cheesed, the layer order and consistence of a coastal deposit stratum are considered and the pile driving method is also considered. This paper introduces the case that the originally box-type sheet pile wall was changed to U-type and high strength material after the pilot test at the subway construction site in a coastal filled land. This paper also introduces the case that the sheet pile's driving method was changed to special method in the section of the temporary coffer dam which had made when the present coastal filled land was formed.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.159-160
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• 2019

Reinforced concrete construction is one of the labor intensive construction projects and its productivity is very low. It is necessary to increase the productivity of rebar construction for improving the productivity of construction work. Therefore, in this study, the rebar drawings of apartment buildings are analyzed to prefabricate wall rebar unit shaped mesh in the factory and installing it on site. If the proposed wall rebar unit is applied to apartment construction working time of wall rebar can be reduced by 50% or more.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.228-229
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• 2014

Recently, to ensure the high openness and prospect right of the building, curtain wall system is mainly applied to the high-rise buildings at domestic and overseas. As a result, the use of Structural Sealant is increasing. Structural Glazing Sealant is applied with the glass and AL-FRAME (Mullion) that the strong structural strength is required to hold. However, the structural sealant at the construction site in a variety of external influences, such as wind load, thermal load, uv, chemical pollutants etc, in case of storing condition, if structural sealant stored in high temperature for a long period time, it will not perform well compared with initial performance. In this study, the influence of the performance of one-component structural sealant evaluated for proper storage conditions at the construction site and how to use the non-intended.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.94-95
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• 2014

Construction industry has become higher, larger and more complicated. It has been analyzed that the process planning in the construction site has been made by the site engineer experience mostly and some were made based on historical data. However, such plans have been investigated that require numerous revisions during construction which means that the plans made through such methods are not reliable. Numerous studies in this field have been conducted trying to solve such problems developing methodologies to overcome such limitations. It has been analyzed that many studies have focused on suggesting prediction models only that cannot be used for both actual planning prior to construction and process monitoring during construction. Therefore, this study suggests a methodology that effectively manages construction productivity by applying simulation methodology combined with bayesian approach focusing on the high-rise curtain wall operations.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.957-962
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• 2010

Foundation systems in urban sites are often necessary to be constructed with little vibrations and displacements to surroundings. In order to assess applicability of a new foundation system for urban sites based on soil-cement mixing technique, vibrations and displacements induced by soil-cement construction process is evaluated. Soil-cement columns were constructed to reinforce soft ground near an old masonry wall in an urban redevelopment site, and the vibrations and displacements of the old masonry wall during construction were measured. Results indicate that the vibrations and displacements induced by soil-cement construction were little and not critical to the stability of the masonry wall.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.520-526
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• 2005

Automation in construction has been restricted to special classes of tasks. Curtain walls can be handled like standard construction materials; they are heavy but breakable, and are large but require precise installation. These characteristics make the installation of curtain walls ideal for robotic automation. There are two methods for developing construction robots: The first is approving the robot performance and applying it to the current construction methods. The second is admitting the limitation of the current robot technology and trying to optimize the current method of construction to apply the robot system. In this study, we derived the performance requirements of a curtain wall-installation robot. We also tested this robot at a real construction site and evaluated its performance. Finally, the results were analyzed, and we proposed additional research.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.1008-1013
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• 2006

Ground anchor method is widely used in the large scale deep excavation of urban area to support a retained wall. Excavation using the ground anchor as a supporting system near a building have many difficulties due to the limitation of construction space. This method can not be applied to the site with the insufficient space from the retained wall to the boundary line. In this case, soil improvement at the anchor bond zone can be used to secure the frictional resistance of ground anchor within the boundary. Through this method, the bond length of anchor can be shortened considerably. This paper deals with the case study on the ground excavation adjacent to a building. The object field is Yongsan Park Tower Construction Site. In this site, the enlarged anchor with soil improvement was applied to solve the problem due to the limitation of construction space. According to the results of field test and monitoring, the anchor with soil improvement is very effective to secure the frictional resistance at the anchor bond zone.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.507-510
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• 2005

Euro form which constructs the present RC structures is used widely by the form method of construction of a wall type structure had much consumption of the human power and equipments by the assembly and the demolition, and the complement was required according to demerit with much leakage of cement paste by the form joint, so it developed the new pillar type form system. On the study, in order to consider the modification characteristic by lateral pressure which does the influence most important for the new developed pillar type form system performance, research of a paper manufactured a miniature wall form model, and advanced performance evaluation focusing on lateral pressure. Moreover, lateral pressure evaluation of a new style system was actually gone on through the on-site experiment about a part of wall type srutcture spot for a model experiment and its result on the foundation which is the purpose in evaluating on-site application possibility propriety at the foundation time of wall type concrete structure construction of a pillar type form system.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.283-284
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• 2012

High-rise building construction has been increasing for the recent years and the construction process has become more complicated. This suggests a need for precise planning based on reliable data to prevent cost overruns and delays. However, the process planning is implemented based mainly on the experience of engineers that can result in critical damage in cost and time. Accurate productivity estimation and unit cost analysis must be considered important matter to prevent such disaster. This study estimates productivity and unit cost of curtain wall operations in high-rise building construction by simulation techniques and statistical methodologies. This study suggests a decision making methodology for the site personnel that enables to compare various combinations of productivity and unit cost based on reliable data that has been collected in actual construction sites. It is expected that this study contributes to the following research of developing an optimized construction performance assembling model for the site personnel.