• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.87-88
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• 2023

In accordance with changes in the domestic construction environment, interest in off-site construction methods (factory-manufactured construction methods) including modular construction methods is rapidly increasing. Among various off-site (OSC) construction methods, the front runner is the steel-based box-type modular construction method. Compared to the existing wet construction method, the steel modular construction method is increasing in terms of securing economic feasibility by shortening the construction period and increasing the prefabrication rate. However, due to the recent rise in raw materials and a sharp rise in the exchange rate, the economic feasibility of the wet method is deteriorating compared to the wet method. Therefore, a hybrid between 9-Matrix-based OSC construction methods is considered as a solution, away from the steel-box type combination, and a comparative study of the construction process between each construction method is being conducted. It was analyzed that the PC modular construction method shortened the construction period by 9% compared to the existing steel modular construction method. On the other hand, when comparing the construction period of the Gayang-dong demonstration complex calculated assuming that all modules are applied, it is estimated that there will be a 12% reduction in construction period compared to the steel modular method and a whopping 43% compared to the RC method.

• Magazine of korean Tunnelling and Underground Space Association
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• v.13 no.3
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• pp.39-46
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• 2011

최근 영국을 비롯한 터널기술 선진국에서는 터널 프로젝트 관련 조달(Procurement) 시스템에 대해 많은 연구 가 진행되고 있다. 조달 시스템은 오늘날 기존의 터널 공법이 발파 버럭제거 보강 공정으로 이어지는 전통적인 NATM 공법에서 TBM 기계화 시공으로 점차 변화하고 있는 가운데, TBM 장비의 설계 구매 조달 시스템은 매우 중요한 공정으로 자리 잡고 있다. 따라서 터널 프로젝트의 조달 관련, 해외 연구 상황을 파악하고 기계화 시공의 핵심 공정인 TBM 조달에 필요한 내용에 관해 알아보고자 한다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.241-244
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• 2010

This paper investigates mainly the new free mandrel technology of the metal spinning. Although the classical spinning, so called conventional, shear, tube spinning, uses the axisymmetric shaped mandrel(which is same inner shape of the final product), new technology does not use it.

• Journal of the Korean Geotechnical Society
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• v.29 no.6
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• pp.63-75
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• 2013

Inclined Earth Retaining Structure Method (IER Method), was developed in order to improve the mechanical properties of the existing earth retaining method. IER consists of two supports, which are front and back supports. In the IER method, back support is very effective for the reduction of the earth pressure acting on the front support. In this study, the effects of back support and fixing conditions of lower ends of supports are analysed by laboratory model tests in clay. The test results show that back support reduces the Leteral displacement of IER effectively, and according to the results the effect of interval and fixing condition of back support was analysed.

• Journal of the Korea Institute of Building Construction
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• v.11 no.2
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• pp.136-144
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• 2011

The form-work operation of concrete structures is a major element determining the period and cost of construction projects. However, the selection of the appropriate form-work system is dependent on the experience of the site personnel only. In this paper, existing methods (Aluminum form, Sky deck) and new slab form-work methods (AFB: Aluminum panel Form with dropping Beam) were selected. Each method was estimated by means of Delphi techniques based on the qualitative analysis data. This paper suggests an evaluation methodology of slab form-work application in construction sites by calculating qualitative evaluation scores. The methodology finding quantified scores of qualitative criteria can be available to be applied to other construction operation evaluation methods.

• Journal of Korea Water Resources Association
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• v.41 no.6
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• pp.619-628
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• 2008

Bank protection is a structure constructed to protect directly embankment breakage and erosion by river flow. Traditionally, the type of bank protection has been decided by practitioner's subjective and empirical judgement, which often causes problems after construction. Recently, however, it becomes important to consider not only physical protection but also environment. Various types of bank protection for environment-friendly river are now available. Thus, there is a need for more objective and quantitative decision method for bank protection work. This study adopts the analytic hierarchy process (AHP) to improve the objectiveness in the decision of bank protection work. Criteria for stability, economy, construction, environment are identified and a standardized process is presented for field application. With the proposed method, one can prioritize various bank protection works and make the optimal decision. We believe that the method can serve as a useful tool for river engineers in practice.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.654-658
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• 2006

To solve some problems that reveals in the exiting stickiness problem of the housetop, the housetop finishing impact layer can be displaced by the existing concrete block. By doing in this way, this need is rising that the excess cost should be reduced and the materials should be recycled in repairing. According to the above, this study is going to suggest the basic data on building and using of the dry process method by estimating and analyzing a overall determinate quantity through the experiment on the insulation performance among the capacity items on the outside insulation waterproof dry process suggested. In addition, choosing the building method according to the use, the peculiar property and the importance of the building can be possible by analyzing the defect causes happening in the rooftop insulation and waterproof, suggesting the better method and classifying the most proper choosing methods for the need of the building according to the importance of the main factors.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.2
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• pp.144-152
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• 2011

The existing underground trenchless methods use reinforcing rod in steel tube to obtain structural stiffness. However, there are some problems such as inconvenience of work and expensive material fee which are resulted from limited working space and reinforcing work. To resolve these problems, a new trenchless method, namely P.S.T method (Prestressed Segment Tunnel Method), is developed which uses joint to connect the steel segment and form erection structure in underground construction. Further, installing strands for prestressing. In order to evaluate the flexural capacity of the P.S.T method structure, experiment was conducted. The parameters considered in the experiment are the span-to-depth ratio, diameter of steel tube at corner, prestressing force and welding of joint. Altogether examining the flexural behavior, the effect of deflection in structure according to different parameters has also been analysised.

• Journal of the Korean Geosynthetics Society
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• v.4 no.1
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• pp.7-15
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• 2005

In recent years, the geotextile tubes filled with dredged material have been used in dike and breakwater construction for a number of projects around the world, and their use in this field is growing very fast. One of the most attractive advantages of geotextile tube technology is can be use the in-situ filling materials by hydraulic pumping, it can be also established lower costs and fast construction than other technology. Geotextiles form one of the two largest groups of geosynthetics and it is commonly made by two major types of polymer material(Polypropylene, Polyester). The objective of this paper is to examine several issues associated with drainage function and feasibility of geotextile tube structure such as filtering efficiency, dewatering efficiency, and filling process with polymer materials. Based on the laboratory filtering test and in-situ tests, polypropylene goetextile is more effective for drainage function of geotextile tube technology.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1058-1062
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• 2010

최근 하천정비 사업은 하천의 치수, 이수적인 기능뿐만 아니라 자연 친화적인 기능을 고려하여 하천을 조성하기 위한 노력들을 많이 하고 있다. 그 결과 기존 콘크리트 호안을 자연형 호안으로 바뀌어 생태계 복원 및 접근성을 높이고, 직선형 하도를 사행하는 자연형 하도로 바꾸는 등의 다양한 하천복원 사업들을 실시하고 있다. 하지만 하천복원에 따른 유지관리를 위한 하천복원공법들에 대한 모니터링과 복원사업에 대한 효과 분석이 제대로 이루어지지 못하고 있다. 따라서 하천복원 전, 후에 대한 모니터링과 평가를 위한 연구가 필요하다. 이에 본 연구에서는 2001년에 시작하여 2006년 12월에 복원 사업이 완료된 오산천 하천환경 정비사업에 적용된 복원 공법들의 수리학적 모니터링을 통해 복원 후의 효과 및 문제점들을 평가하였다. 우선 수리학적 모니터링의 일반적인 사항으로 강우량 및 홍수량 측정, 하상변동 분석, 하상재료 분석 그리고 항공영상 분석을 수행하였다. 또한 복원 공법에 대한 수리학적 모니터링은 호안의 수리학적 안정성 평가, 어도의 기능 평가, 저수로내에 설치된 인도교 주변과 목교의 수리학적 영향을 분석하였다. 모니터링 결과 복원 후 일부 목교 주변과 자연형 호안 중 일부는 침식되었으며, 하중도 하류부에는 퇴적이 발생한 것을 확인하였다. 금곡취수보에 설치된 어도는 자체안전성에는 문제가 없었으나, 어류 소상을 위한 기능을 다하지 못하는 것으로 확인되었다. 또한 상류 하천정비로 인해 하류에 퇴적이 많이 되어 있는 것을 확인하였다. 이와 같은 적용 공법별 수리학적 모니터링 결과는 복원 공법에 대한 모니터링 및 평가를 위한 지침서 작성을 위한 기초자료로 사용될 것으로 기대된다.