• Journal of Korean Society of societal Security
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• v.1 no.4
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• pp.51-56
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• 2008

Because of our country's climate that has the 50% of the annual precipitation in summer, annually a lot of bridges on the roads are broken in this season. So, we need an accelerated bridge construction method that complete to repair the roads. This paper introduces the Hangae 2 bridge, prefabricated bridge using full depth precast deck panels and new types of PSC girders. The Hangae 2 bridge located in lnje-gun, kangwon-do. This is a good example of the accelerated bridge construction method for recovery of flood damaged road. The PSC girder bridge system introduced in this paper is a rapid construction method for bridge that can reduce the term of works over 50%.

• Journal of Korean Society of Steel Construction
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• v.23 no.3
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• pp.295-304
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• 2011

Bracket-type connection is often used for the weak-axis steel connection. In general, a beam-to-column connection for the bracket type is fabricated at the shop and abeam splice is additionally attached to the bracket in the site. Therefore, steel construction would not be competitive due to the increase of beam splice fabrication cost and overall construction period. This paper now proposes the new weak-axis connection types without a scallop, which has more definite strength flow, simple connection details, and better workability. From the series of experiments, the proposed connections showed better strength and ductility in comparison with standard details with scallop because the thickness of the welding plate for wide-flanged, beam-to-column connection can be easily adjusted.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.273-274
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• 2009

The curing method used on domestic sites for checking the concrete compressive strength of a structure. The curing method used for testing the specimens must be the standard ponding curing method (20${\pm}$%$2^{\circ}$C). However, because in-placed concrete is exposed to open air and cured under the seasonal temperature changes, the compressive strength of a real structure is different from the tested compressive strength. Therefore the curing method suggested in this research, which sets the internal conditions of the structural specimens as the conditions of the applied curing method. this thesis suggests the specimen curing method that most closely re-enacts the compressive strength of the concrete used on the structural specimens

• Korean Journal of Construction Engineering and Management
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• v.12 no.6
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• pp.14-21
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• 2011

A unit modular system is a construction method which installs on site by manufacturing 50%~90% of the whole process in the factory. This method can minimize the process in the site and maximize the operation, which will reduce the duration and improve the overall quality. The recent paradigm of construction is to be sustainable building. Modular system can be regarded as a sustainable building construction method because it can reduce the amount of construction waste by recycling partial or whole part of overdue building be torn down. A unit modular system is the answer to cope with the increasing market of small size housings. A unit modular system is the most appropriate option at this point. This research proposes the standard operation and construction process of modular system, which enable to optimal system. A case study of reconstructing small-size housing was introduced to support this proposal. Finished unit modular is the reasonable way. However, 80% of complication rate of the modular is the most rational when a defect occurrence during delivery is considered.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.4
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• pp.427-434
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• 2017

The generation of construction waste can be divided into a decommissioning phase and a new construction phase, and most of the waste is generated at the decommissioning stage. However, recently, domestic new construction construction has expanded to 150 trillion yards per year, so construction work is increasing rapidly. Especially, as the size of the construction work with much waste of construction waste exceeds 100 trillion, the management of the amount of construction waste in the new construction site is required. Unlike the dismantling work site, the new construction site can separate waste generated by each property, and relatively low foreign matter content is generated. The purpose of this study was to investigate the amount of construction waste generated by new construction sites and to calculate the unit amount of construction waste based on this. In addition, since the existing unit cost is centered on concrete and mixed waste, we set the basic unit by setting synthetic resin, waste wood, and waste board as additional items. The basic unit survey was carried out to investigate the wastes according to the characteristics of each construction period. As a result of the survey, the new construction site showed that most wastes were discharged in the first 30% and after 70% of the process, and the ratio of mixed construction waste was as high as 45%. As a result of this study, it was found that about twice as much waste was produced as compared with the conventional standard product.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.1207-1208
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• 2012

최근 건설분야에 화두가 되고 있는 건축정보모델링(BIM, Building Information Modeling)은 건설산업의 패러다임 전환을 통한 새로운 성장동력의 미래로 부각되고 있으며, 건축분야는 서울시, 용인시, LH공사 등 BIM을 활용한 공공 발주사례가 확산되는 추세다. 토목분야는 건축보다 기간이 길고 비용이 크며 이해당사자가 너무 다양해서 발생하는 정보의 양이 방대할 뿐만 아니라 활용분야를 다양화하지 못하고 이를 뒷받침해주는 제도나 지침의 부재 등으로 인해 건축분야보다 BIM도입이 늦어지고 있다. 이에 토목분야에서 활용할 수 있는 3차원 형상정보와 관련된 정보모델표준, 지침, 가이드를 개발하기 위해 BIM 적용시 가장 효과가 크고 도입의지가 강한 엔지니어링사의 BIM에 대한 인지도 분석을 통해 토목분야 BIM 도입을 위한 기초자료로 활용하고자 한다.

• Journal of Cadastre & Land InformatiX
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• v.50 no.2
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• pp.53-68
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• 2020

The Cadastral Renovation is a National project to investigate and survey the registration of Cadastral Record and replace the existing Cadastral Record with a new Cadastral Record by digital, and to correct the registration of Cadastral Record if the registration of Cadastral Record does not match the actual status of the land. The Business Period generally takes about one year and six months to two years. The time required is getting longer due to problems that occur in the course of the Adjustment amount after the cadastral resurvey survey due to complex structure and internal conflict due to the interest between landowners. After Boundary Decision of the real boundary, the land area is confirmed by the landowners, and the cadastral office is to settle the Cadastral Renovation by calculating the Adjustment amount according to the confirmed area and the increase and decrease of the cadastral area. Therefore, the solution plan was suggested so that reasonable Adjustment amount can be applied through empirical research applied to the time of calculation of Adjustment amount and the method of calculation of Adjustment amount. The improvement method showed the expected effect that can lead the agreement with the landowner to the shortest period, and it was also possible to set the real boundary that meets the purpose of the Cadastral Renovation. This study suggests improvements in the method of calculating standard Adjustment amount, the method of imposing Adjustment amount, and the method of boundary adjustment that does not impose adjustment amount through the cadastral Renovation and parallel studies, and it is expected that the Cadastral Renovation will be completed by 2030.

• Korean Journal of Construction Engineering and Management
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• v.23 no.3
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• pp.13-24
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• 2022

Construction projects are exposed to various types of risks, which tend to increase. The increasing risks call for contractors' more attentions to forecasting and dealing with these risks. One of the measures to deal with contractors' risks is to forecast or estimate risk cost and include it in the construction budget. Although various researches in relation to risk cost have been observed, little attention has been paid to general contractors' perceptions and current practices in estimating risk cost of construction budget. The objective of the study is to identify and discuss key characteristics and implications based on the survey and analysis of general contractors' perceptions and current practices in estimating risk cost of construction budget. The study shows that there is a gap between the perception and the practice of estimating risk cost, that is, high perception of the importance of risk cost and a relatively low level of practice. It suggests that historical cost data, guidelines and corporate-level standard procedures are required to improve the current practice in addition to sufficient time allocations for risk cost estimating. It discusses that there is a need for using sophisticated estimating techniques including bid data analytics despite a low level of the current adoption, and also proposes that research and development in the field of the sophisticated estimating techniques should be further implemented in order to increase their practicality.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.965-968
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• 2008

The KS F 2403 method used on domestic sites for checking the compressive strength of a structure, sets the compressive strength of the concrete used in structural specimens as the compressive strength of testing specimens. Under this regulation, the curing method used for testing the specimens must be the standard ponding curing method (20$\pm$2$^{\circ}$C). However, because in-placed concrete is exposed to open air and cured under the seasonal temperature changes, the compressive strength of a real structure is different from the tested compressive strength. (Therefore,) This thesis first identifies the distinct characteristics of the strength development by applying the curing method listed under the KS and used for testing specimens on compressive strength tests; the atmospheric curing method, the sealed curing method, and the structural specimen core strength testing methods used for the in-sites quality checks including reckoning of the compressive strength of the structural specimens and form-demolding period; and the curing method suggested in this research, which sets the internal conditions of the structural specimens as the conditions of the applied curing method. Then, the thesis suggests the specimen curing method that most closely reenacts the compressive strength of the concrete used on the structural specimens

• Journal of Korean Society of Steel Construction
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• v.20 no.6
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• pp.793-805
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• 2008

Recently, steel modular systems are developed and have been applied to the projects requiring fast construction such as military barracks and vertical expansion of school buildings. The existing modular system with standard module of ${6m\times3m}$ has a problem that many columns are duplicated in the module connection and the wall thickness increases. In this study, $12m{\times}3m$ module is proposed to solve this problem. Various types of beam-middle column connection which are essential for realizing the $12m{\times}3m$ module are proposed and their maximum load capacity and failure mode are analytically and experimentally evaluated. The comparison between analytical and experimental results shows that the maximum axial load and failure mode can be accurately estimated by finite element analysis. Some connection types which have higher failure load than the design load of the column, can be used as the beam-middle column connection detail of the $12m{\times}3m$ module.