• Journal of the Korea Institute of Building Construction
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• v.22 no.3
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• pp.293-303
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• 2022

In construction work, it can be difficult to know the exact number of full-time workers, so the accident rate is calculated using the approximate number of full-time workers. In addition, as the accident rate calculation is performed based on the assumption that the number of accidents is proportional to the approximate number of workers, the reliability of the calculation result may be questionable. This study proposed a new indicator for accident level based on the progress payment and the number of injuries. The accident-progress ratio, which can be calculated by simply dividing the number of injuries by progress payment, can replace the existing accident rate index or be used as an auxiliary indicator of the accident level. The correlation coefficient between the number of injuries and the progress payment was higher than that between the number of injuries and the number of construction workers. In addition, over the past 10 years, the accident rate has been increasing, whereas the accident-progress ratio has showed a decreasing tendency. This might leave room for different interpretations of the annual variation in the accident level in the construction industry.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.6
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• pp.843-852
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• 2022

Despite continuous safety management, the death rate of construction workers is not decreasing every year. Accordingly, various studies are in progress to prevent construction site accidents. In this paper, we developed an AI-based priority inspection target selection model that preferentially selects sites are expected to cause construction accidents among construction sites with construction costs of less than 5 billion won (KRW). In particular, Random Forest (90.48 % of accident prediction AUC-ROC) showed the best performance among applied AI algorithms (Classification analysis). The main factors causing construction accidents were construction costs, total number of construction days and the number of construction performance evaluations. In this study an ROI (return of investment) of about 917.7 % can be predicted over 8 years as a result of better efficiency of manual inspections human resource and a preemptive response to construction accidents.

• Korean Journal of Construction Engineering and Management
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• v.5 no.6 s.22
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• pp.170-178
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• 2004

Public construction companies have strictly followed a rule that they should not work in the wet area such as structural frame for a certain period during the winter season. It is usually known that the non-working period during the winter causes increase of the project duration, and the project cost escalation. Also, it makes negative effects on national economy because it reduces workers income. Therefore, the site work for the structural frame should be performed even during the whiter season. But the site work for the structural frame during that period cannot proceeds in the same way as during other periods, and requires a different method for estimating project duration. Through an analysis of time scheduling mechanism, actual working days are obtained for 1 cycle of typical floors in the structural frame during these periods, and non-working days of 5 years average are calculated based on calendar day using data of 5 years weather forecasts for that season. This study proposes an optimized way of estimating project duration for 1 cycle of typical floors in the structural frame during these periods. This estimating method uses the combined actual working days and non-working days of 5 years' average, and the estimated results are confirmed by being compared with field data. This study is expected to be used in estimating the construction duration of the structural frame during the winter season.

• Journal of the Korea Institute of Building Construction
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• v.20 no.2
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• pp.137-145
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• 2020

The recent bridge construction projects demand thorough and systematic safety and risk management, due to the increase of risk factors following the introduction of new and complex construction methods and technologies. Among many types of damages that can occur in bridge construction projects, the damages to third parties who are not directly related to the existing property of the contractor construction project can also bring about critical loss in the project in order to compensate the damages. Therefore, risks that could be caused by the loss occurred to indemnify the third party damages should be clearly analyzed, although there are not subsequent amount of studies focusing on the issue. Based on the past record of insurance payment from domestic insurance companies for bridge construction projects, this study aimed to analyze the risk factors of bridge construction for loss caused to compensate the third-party damages happened in actual bridge construction projects and to develop a quantified and numerical predictive loss model. In order to develop the model, the loss ratio was selected as the dependent variable; and among many analyzed independent variables, the superstructure, foundation, flood, and ranking of contractors were the four significant risk factor variables that affect the loss ratio. The results produced can be used as an essential guidance for balanced risk assessment, supplementing the existing analysis on material losses in bridge construction projects by taking into account the third-party damage and losses.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3D
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• pp.457-468
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• 2011

Recently, the non-vibration mass excavation method is used on sewage pipes and road construction sites in Jeju. However, a construction cost estimation based on the unit quantity does not provide a proper unit price. In this study, a comparison of the productivity of the standard quantity-per-unit costing method and the one of the work crew combination method was made based on the site monitoring of the non-vibration mass excavation method that is used in construction sites near Jeju. For this, data of 35 sites were collected: a regression equation was derived from the 30 data, and verification was carried out through the remaining 5 data. The analysis concluded that a day's workload is $16.43m^3$. In addition, a combination of the equipment considering the site conditions and the amount of labor, which varies with the number of work crew was obtained in order to estimate the construction cost of the work crew combination method. The construction cost was calculated based on the one-day workload ($16.43m^3$) derived from the regression analysis. The cost then was analyzed and compared with the standard quantity-per-unit costing method.

• Korean Journal of Construction Engineering and Management
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• v.15 no.3
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• pp.38-46
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• 2014

The Global's top five Design Firms selected from BauNetz a German architectural magazine in 2007 designed free form building design which was 25% of the overall design by 2006-2010. Free form building is a landmark of the city and the country so its social and economic impacts are very large. In case of Korea, free form buildings such as Tribowl in Incheon, KINTEX Exhibition hall 2 and Dongdaemun Design Plaza have increased. However, those the increase in design trends and, the needs due to the lack of free form building design and construction management experience, free form building projects can't be expected to profitability and have a number of problems after completion. Especially, there are many excessive quality problems and the rising cost due to design changes frequently and lack of experience and data. Thus an initial plan regardless of considering of free form building's characteristics can be a huge risk because of the difference with the plan and actual projects, yet there aren't free form building project's performance data and case studies related to productivity. In this study, through selection of low-construction productivity works and an analysis of the work process and productivity data, hope to propose an actual field productivity of free form building and the ways to improve productivity.

• Journal of Korean Society of Transportation
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• v.22 no.7 s.78
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• pp.41-48
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• 2004

We may consider the inducement of demand to public transportation as a solution to relieve traffic congestion and pollution. Subway has merits as moving on schedule, transporting more people than bus. But subway is required a vast investment in the early stage of construction has a huge debt. So it runs into red figures, and on this account, services of subway are falling more and more. Development of subway's operation cost function is useful to understand structure of subway's operation and catch the relations of operation cost and actual results. In addition, we can present the policy that is a helpful to the operation as development of operation cost function. But there are short of studies about operation cost deal with a subway comparison with local train. Because local train has many lines and data, on the other hand, subway has one to four lines and less data. Most of previous studies sought the operation cost function of Seoul. So this study aimed to develop and apply the operation cost function of Seoul, Incheon, Busan and Daegu area using full allocation method. In this study, we considered the number of passengers, track-km, train-km, revenue as actual results. By appling the operation cost function, we compared the average cost of each city and confirmed the existence of economies of scale about the number of passengers, train-km.

• Journal of Korean Society of Transportation
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• v.35 no.5
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• pp.458-467
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• 2017

The expressway of the Korea has an important role in freight movement because 76 percent of the commodity is transported by trucks. However, there has been few indices on the role of expressways regarding freight transportation and truck traffic. The objective of this study is to propose four freight transportation related indices using ITS-related system such as TCS and HS-Wim: total truck's travel miles ($veh{\cdot}km/year$), total freight transport miles ($ton{\cdot}km/year$). efficiency of truck's travel ($veh{\cdot}km/km$), and efficiency of freight movement ($ton{\cdot}km/km$). These truck and freight related indices were estimated and compared by two different data sources: traffic volume data using VDS and OD data using TCS. These indices were designed to estimated on real time and updated every day and month.

• Korean Journal of Construction Engineering and Management
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• v.4 no.4 s.16
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• pp.220-226
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• 2003

The Residential Building Cost Index which presents price variation of construction resources required in a residential building project in single value, has been compiled to evaluate appropriate level of the price variation. This research reviewed the compilation methodology for Residential Building Cost Index based on comparative analysis on domestic statistics and proposed the Residential Building Cost Index through a variety of case studies. It would facilitate monitoring the price variation of a residential building cost and contributes to enhancing the applicability of construction cost data.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1993.04a
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• pp.475-482
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• 1993

지금까지지 PERT/CPM기법은 대형 Project 및 건설공사등의 공정관리업무에 주로 활용되어 왔으며 공정관리분야에 커다란 기여를 해 왔다. 본 연구에서는 이러한 PERT/CPM기법의 새로운 적용분야로 각종설비의 정비(Maintenance) 또는 수리(Repair)작업에의 Approach를 시도했다. 에너지 설비는 제철소내 80여개 설치되어있으며 설비별 수리주기, 에너지수급 Balance 정비인원등의 요소를 고려해 년간 계획수립 후 수리를 실시하게 된다. 일련의 수리작업관리는 경험에 의한 수작업 공정표작성, 계획수립 및 진행관리등으로 공정관리에 많은 어려움을 겪고 있다. 이러한 수리작업 공정관리, 즉 수리계획수립, 진행관리 및 실적관리에 이르는 업무를 효율적으로 수행하기 위해 SAS(Strategic Application System) S/W를 활용하여 System을 개발하였다.