• Korean Journal of Construction Engineering and Management
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• v.13 no.3
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• pp.43-55
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• 2012

A methodology for BIM Quality Assurance in the construction industry is becoming increasingly an important issue to determine the reliability of BIM. However, the quality assurance of BIM is currently limited to check 3D models, such as clash detection and space layout while verification methods for disciplinary BIM results from structural engineering, mechanical engineering, and estimation do not exist yet. Particularly, in the BIM-based estimation mathematical equations to take off quantities are not clearly exposed so that the results are not quite accepted at practices. With the concept of reliability engineering defined in the manufacturing industry to improve reliability of outcomes of BIM-based quantity take-off, impacting factors that affect reliability of BIM-based quantity take-off were derived. It was found that the factors also include the modeling method and the features of a BIM tool. Therefore, this research aims to propose modeling and verification methods to improve reliability of BIM-based quantity take-off through the pilot test that was performed with commercial BIM tools and IFC-based BIM data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.7A
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• pp.1117-1123
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• 2001

본 논문에서는 국내 IMT-2000 이동통신 사업의 경제성을 분석한다. 투자비 산출을 위해 IMT-2000 망 구성요소를 추출하고 각 구성요소별 설비물량을 구한다. 이를 위해 IMT-2000 가입자의 기준트래픽 및 기지국의 용량을 수율(throughput)의 단위로 평가하여 기지국의 소요 물량을 산출하고 기존 2세대 이동통신 시스템의 종단용량을 기준으로 핵심망 부문의 설비물량을 구한다. 동기식 및 비동기식의 기술방식과 기존 시스템의 활용도를 고려하여 발생 가능한 시나리오를 설정하고 각 시나리오별 경제성을 비교, 분석한다. 그리고 시장 점유율 변화에 따른 순이익 변동을 평가한다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.2
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• pp.655-666
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• 2014

Recently, as the appearance and exterior design of the construction structure are highlighted, the irregularly shaped structures are increasing in a construction facility. Many softwares provide a quantity take-off function of 3D object under BIM environment, however, they are focused on the limited function based on the solid modeling method. Because the vast geometric information of the curved surface is difficult to extract in the 3D objects that consist of major changes in vertical section shape as the irregularly shaped structures, it is difficult to express a 3D object as a solid model. On the other hand, the irregularly shaped structures can be expressed in relatively free in the surface model because the surface model consists of points, lines and surfaces. Accordingly, the surface modeling method is suitable for the modeling of large irregularly shaped structures. This study suggests a quantity take-off algorithm for the irregularly shaped structures using the surface modeling approach that is beneficial in the design work of structures. Some case projects are used for verifying the accuracy of the proposed method.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.5
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• pp.447-454
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• 2016

In the meantime, looking at the present status of how to estimationte the quantity of rebar based on 3D BIM getting the limelight in these days, commercial BIM tools provide rebar modeling functions however it takes a vast amount of modeling time for modeling of rebar in use of that function hence there is no BIM software at present for practical use. Therefore, in this study, we organized and presented a practical rebar quantity estimationtion process in BIM-based design work-site and intended to develop a program named Rebar Automatic Arrangement Program - hereinafter called RAAP - which enables automatic rebar arrangement based on much more precise cross-sectional information of bars in column, beam, slab and wall than the one from existing 2D method under the conditions without any cross-sectional information in the initial design phase. In addition, we intended to establish rebar quantity estimationtion process in the initial design phase through interworking of modeling & quantity estimationtion functions in consideration of joint, anchoring length of BuilderHUB as a BIM software with RAAP. The results from this study are practical in developing a technology that is able to estimationte quantity with more improved reliability than the one from existing 2D-based methods with less effort when the quantity of framework is estimationted in the uncompleted state of cross-sectional design for structural members in the initial design phase of a construction project. And it is expected that it could be utilized as a basic study from which a reasonable quantity estimationtion program can be established in the initial design phase.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2009.04a
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• pp.513-516
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• 2009

본 논문에서는 사례연구를 통하여 RC구조 BIM에서의 물량정보 획득의 효율성을 분석하고 이를 기반으로 BIM 프로세스 환경에서의 철근 및 콘크리트 물량산출을 위한 데이터베이스를 구축하여 현장 시공단계에서의 공정 및 물량관리의 협업단계를 가능하도록 하는 철근 Sorting 시스템에 대한 연구를 목적으로 한다. 기존의 건설, 건축분야에서의 정보는 기호적 언어와 2차원 기반의 도면 정보체계를 통해 표현되었지만, BIM 기술을 통해 건물의 실제 형상과 정보를 가지는 3차원 기반의 정보체계로의 변화와 함께 컴퓨터 데이터베이스 내에서 프로젝트에 포함된 모든 정보를 저장하고, 다양한 형태로 필요에 따라 정보를 표현할 수 있게 변화하고 있다. 견적 및 시공을 위한 RC구조설계단계에서의 배근 모델은 협업을 위한 객체 정보의 획득 및 추출이 중요하지만 현재 상용되고 있는 BIM도구에서는 현재까지 미흡한 체계를 이루고 있다. 본 논문에서는 구조설계를 기반으로 배근된 BIM 구조모델 사례를 통하여 기존 BIM도구에서의 물량 정보획득 효율성 분석을 기반으로 객체들의 데이터베이스 구축을 통한 철근 Sorting 시스템 구축 연구를 통하여 협업단계에서의 체계적 물량정보 관리를 가능하도록 하였다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.1
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• pp.35-44
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• 2020

In the construction industry, there is a growing demand for the accurate calculation of the quantity take-off and construction budget at the design stage, and it is likewise important to grasp changes in the construction budget and quantity take-off if design alterations are made. In addition, lawsuits related to the quantity take-off and cost of construction are frequent; therefore, the calculation of these factors using building information modeling (BIM) has emerged as an alternative. However, existing 2D-based methods are still used more frequently than BIM-based methods for quantity take-offs and construction budgets. This is because of the lack of BIM experience of estimation workers and the absence of a national standard. However, from a designer's point of view, it is necessary to understand the quantity take-off and construction cost based on BIM and accurately create the design according to the budget. In this study, the quantity take-offs of concrete, rebar, and reinforced concrete structures (apartments) in Seoul and Yeongjong were compared with the quantity take-offs based on 2D and BIM methods. From the viewpoint of the designer, we aim to increase the accuracy of BIM-based quantity take-offs.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.101-104
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• 2010

본 논문에서는 구조설계, 철근배근시공도 작성, 골조 물량 산출, 3D BIM 모델 생성 등 기존에 독립된 업무로 수행되던 골조공사 관련 엔지니어링 업무를 통합 수행하는 골조공사 관리시스템 ConiForm을 개발하여 2차원 CAD로부터 3D 골조모델 생성하고, 3D 모델로부터 철근의 이음/정착/철근길이 등을 반영한 철근배근시공도 및 가공도 작성과 골조물량을 산출하여, 3D BIM 도구와의 연동함으로써 정밀 물량 및 견적을 자동 산출하고 건축모델과 구조모델 간 정보공유 및 통합 BIM 실현 등을 제시하고자한다.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.143-144
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• 2011

Recently the construction project is intricately linked to the between participants. it is because construction informations are not integrate. This study suggests 3D modeling standard for integrated construction information. These suggestions can be useful to automation quantity take-off.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.43-44
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• 2009

3D bridge information models for a concrete box-girder bridge were built and a typical application example for the estimation linked with the 3D models was proposed. 3D geometry objects with PBS (product breakdown structure) were constructed using standard classification codes and 2D drawings. Information on the amount of materials according to the classification codes was utilized for the estimation system. A process for the estimation of concrete and rebars was developed and verified through the pilot test. Optimization of rebar fabrication was suggested as an additional function and was utilized for the cost reduction and standard fabrication.

• Korean Journal of Construction Engineering and Management
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• v.13 no.1
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• pp.118-128
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• 2012

As the bearing wall structure, which has been widely applied to domestic apartment buildings since the 1980s, cause many problems during remodeling of buildings, the government encourages constructors to adopt flat plate or rahmen structure through legal incentives. In line with such a trend, the green frame, an eco-friendly rahmen structure that has removed the shortcomings of previous structures, was developed to enhance structural safety, constructability, and eco-friendliness. The construction of green frame can reduce the labor cost and facilitate the composition of iron bars to reduce rebar loss through calculating the quality and establishing the bar bending schedule automatically on the precast concrete member data collected over the design phase. Therefore, the purpose of this study is to develop the algorithm to automate the calculation of iron bar volume for the green frame designed on composite precast concrete members. Automated algorithm to calculate concrete structural design information and design information. Practices through the application site should prove efficacy. The database established by the developed algorithm will automate the establishment of iron bar processing map and bar cutting list and the calculation of optimal composition and order volume to minimize the rebar loss. This will also reduce the expenses on management staff and overall construction cost through the minimization of rebar loss.