• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.4
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• pp.705-716
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• 2017

As many environmental pollution problems have arisen, various studies related to the environmental evaluation have been carried out in the construction industry. However, there is no methodology for estimating the environmental load quickly for design alternatives of civil facilities in the design phase. This study aim to establish criteria of works information and designed parts which can efficiently estimate environmental loads of PSC beam bridge based on standard quantity at the early design phase. For this purpose, a detailed environmental loads database was constructed by performing Life Cycle Assessment (LCA) based on detailed design data of 25 bridges. In addition, major work with high impact on environmental load were selected, and the analysis of characteristics of environmental load according to the required materials and 8 impact categories were conducted. As a result, the superstructure accounted for 42.91%. In the superstructure, remicon of the material base and PSC beam work occupied 53.13% and 31.25%. In the substructure, remicon, rebar, and cement, which are material base, accounted for more than 93%. It is expected that this major work and material information for each part of bridge can be utilized in the construction of the model, which can estimate the approximate environmental load, reflecting the characteristics of the structure in the design phase.

• Journal of Korean Society of Forest Science
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• v.110 no.4
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• pp.630-647
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• 2021

We determined the current problem of the restoration deposit-estimation system, stipulated by the Mountainous Districts Management Act, using the Delphi technique. Consequently, we proposed a standard model for forest land restoration to derive a reasonable deposit-estimation system. With the result of the Delphi survey, the inappropriateness of land-use type and slope gradient classifications was shown; the insufficiency of standard works was a significant problem in the current system. A way to solve these problems was devised, to reorganize the current land-use type into the subject of the site. The specific subjects included the following: (i) to permit or report forest land-use change and temporary use of forest land, (ii) to report temporary use of forest land, (iii) to permit stone collection or sale for mineral mining, and (iv) to allow sediment collection. The current slope gradient subdivision into (a) θ<10°, (b) 10°≦θ<15°, (c) 15°≦θ<20°, (d) 20°≦θ<25°, (e) 25°≦θ<30°, and (f) θ≧30° and the reorganization of 17 standard works into 22 standard works were deemed as solutions, along with seven additional works. We developed 24 standard models for the forest land restoration project based on the aforementioned results. The deposits estimated by these models ranged from 34,185,000 (Korean) won to 607,403,000 won. If additional works, premiums, discounts, and supervision fees are added to the models, the deposit increases to an estimated 668,143,000 won subject to permission for stone collection or sale and mineral mining. Experts agree on the distribution of the restoration deposits estimated by these models at a high level in the Delphi survey. Our findings are expected to contribute to securing the appropriateness of the restoration cost deposited for the smooth performance of the vicariously executed restoration project.

• Journal of the Society of Disaster Information
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• v.8 no.4
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• pp.328-335
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• 2012

The resource-based estimating based on standard unit price of construction work was estimated by multiplying the price per standard unit of work on the amount of labor, material, equipment use time. However, limitation of the resource-based estimating way does not adequately reflect the actual transactions prices. On the subject of water tunnel excavation as a new attempt to overcome these limitations, this study analyzed productivity by work type into cutter inspection/ exchange, TBM maintenance, TBM inspection/refueling, subsequent installations, tramcar, operating change, a cave-underground reinforcement / rock reinforcement, safety / meetings and analyzed actual cost estimating and the net advance rate based on this analysis result. Actual cost estimating calculation approach presented in this study can be utilized as a useful tool to predict the actual cost estimating in the TBM water tunnels field.

• Journal of Convergence for Information Technology
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• v.10 no.2
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• pp.1-8
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• 2020

The standardized procurement of supervisory cost for the construction of domestic Information and Communication Technology(ICT) facilities, which is announced by the Korea Engineering and Construction Association in May 2009, has been applied in the public institutions and private industries. However, the previous standardized procurement is not widely applied in recent years because the ICT and social economic environment have been rapidly changed and the previous equations to calculate the supervisory cost is not simplified. As results, the needs for a new standardized procurement has been increased and the Ministry of Industry, Commerce and Energy has published a notice with new standard procurement. In this paper, we provide the explanation of the background and the derivation process of the notice based on authors' experiences of project participation. As research method, we compare the previous mad-day cost of ICT construction and that of another area including electric facility construction, and then we explain a new procurement equation based on WBS(Work Breakdown Structure).

• Korean Journal of Construction Engineering and Management
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• v.19 no.3
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• pp.70-78
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• 2018

Due to the increasing concern about climate change, efforts to reduce environmental load are continuously being made in construction industry, and life cycle assessment (LCA) is being presented as an effective method to assess environmental load. Since LCA requires information on construction quantity used for environmental load estimation, however, it is not being utilized in the environmental review at the initial design stage where it is difficult to obtain such information. In this study, a construction quantity computation system based on the standard section was developed for the drainage facilities of the road and utilized in the model to calculate the environmental load. This model can estimate the environmental load by calculating the amount of resources required for LCA using only the information available at the initial design stage. To verify the validity of the model, five validation cases were applied and compared with the unit estimation model and the multiple regression analysis model. As a result, it is confirmed that the mean absolute error rate is 9.94%, which is relatively accurate and effective model in the initial design stage.

• Journal of the Society of Disaster Information
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• v.17 no.3
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• pp.608-616
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• 2021

Purpose: Safety inspections by existing personnel have been limited in evaluation and data securing due to concerns about the safety of technicians or difficulty in accessing them, and are becoming a bigger problem as the number of maintenance targets increases due to the aging of facilities. As drone technology develops, it is possible to ensure the safety of personnel, secure visual data, and diagnose quickly, and use it is increasing as safety inspection of facilities by drones was introduced recently. In order to further enhance utilization, it is considered necessary to base a consideration standard for facility appearance investigation by drones, and in this paper, research was conducted on dams. Method: To calculate the quality, existing domestic safety inspection and drone-related consideration standards were investigated, and procedures related to safety inspection using drones were compared and analyzed to review work procedures and construction types. In addition, empirical data were collected through drone photography and elevation image production for the actual dam. Result: Work types for safety inspection of facilities using drones were derived, and empirical survey results were collected for two dams according to work types. The existing guidelines were applied for the adjustment ratios for each structural type and standard of the facility, and if a meteorological reference point survey was necessary, the unmanned aerial vehicle survey of the construction work standard was applied. Conclusion: The finer the GSD in appearance investigation using drones, the greater the number of photographs taken, and the concept of adjustment cost was applied as a correction to calculate the consideration standard. In addition, it was found that the problem of maximum GSD indicating limitations should be considered in order to maintain the safe distance.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.1
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• pp.95-105
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• 2022

Recently, as the scale of a construction project has become larger and more complicated, there are many cases where construction projects with complex structures are carried out in a fast track method to save construction duration. In the fast track method, the proper division of construction phases is an important issue in determining the overall project period. This study presents a rational phase division method that can be applied when a construction project with complex structures is carried out as a fast track. For this study, a subdivided work breakdown structure (WBS) is developed using the construction of 4 soccer stadiums as application examples, and the schedule is analyzed by dividing the construction process of major phases. To this end, five proposals are applied to analyze the adequacy of the fast track phase division. For the draft with the minimum construction period, the fast track phase division and the schedule model of by each phase were presented. This methodology can have an application in the appropriate phase division and schedule model by construction phase when fast track is applied in large construction project of a similar size.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2118-2119
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• 2011

체계화된 전기공사의 내역서 작성은 공사의 품질관리 및 공정관리를 원활하게 할 수 있는 기본이 된다. 공사의 혼란을 초래하지 않으며 업무의 효율화를 기할 수 있는 일목요연한 내역서 작성이 필요하다. 따라서 본 연구에서는 우선 내역서 자체가 가지고 있는 문제점을 해결하는데 중점을 두고자 한다. 즉 현행 내역서 문제점인 단위공종 및 규격의 표준을 제시 및 용어통일을 기하고자 하며, 주요 발주기관에서 운용하는 내역특성, 발주특성을 조사후 장단점을 파악하여 향후 내역서 간소화 및 단순화 작성의 기초적인 데이터를 확보하고자 한다.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.10a
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• pp.278-282
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• 2008

U-국토 및 U-도시의 건설 및 관리를 위해 정밀 국토공간정보의 수요가 점증하고 있고 보다 신속한 갱신이 요구되고 있는 가운데 유비쿼터스 기술들과 융복합된 u-GIS기술에 대한 요구 또한 증가하는 추세다. 특히 건설 분야에 있어서의 이러한 수요를 보다 심층적으로 파악하기 위해, 건설공사 표준품셈 등을 이용하여 건설공사 공종/공정을 분류하고 이에 대한 수요의 우선순위를 도출하는 연구를 수행하였다. 본 논문은 u-GIS 기술을 필요로 하는 건설 현장에 위치/형상 정보 수요에 대한 조사, 분석을 통해 건설 인력, 자재, 장비의 u-GIS 기술의 적용 우선순위를 도출하는 것이다.

• Magazine of the Korean Society of Agricultural Engineers
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• v.40 no.3
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• pp.35-41
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• 1998

Cost estimate system Will be changed from the prime. cost calculation to the historical cost data because the present system has some problems. In this situation, each owner should prepare his own cost estimate system based on the historical cost data. In this study, the standard work items were classified and the criteria of their work amount computation were established for rural improvement projects. And also the historical cost data were collected in all range of rural improvement projects, and the database system, "HICOMS" (HIstorical COst data Management System) was built. In order to test the applicability of the HICOMS, standard work cost and contractor cost were compared. The results by HICOMS showed high significance and it was concluded that the HICOMS could be applicable for the cost estimate of the rural improvement projects. projects.