• 제목/요약/키워드: construction time and costs

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A Markov-based prediction model of tunnel geology, construction time, and construction costs

  • Mahmoodzadeh, Arsalan;Mohammadi, Mokhtar;Ali, Hunar Farid Hama;Salim, Sirwan Ghafoor;Abdulhamid, Sazan Nariman;Ibrahim, Hawkar Hashim;Rashidi, Shima
    • Geomechanics and Engineering
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    • 제28권4호
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    • pp.421-435
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    • 2022
  • The necessity of estimating the time and cost required for tunnel construction has led to extensive research in this regard. Since geological conditions are significant factors in terms of time and cost of road tunnels, considering these conditions is crucial. Uncertainties about the geological conditions of a tunnel alignment cause difficulties in planning ahead of the required construction time and costs. In this paper, the continuous-space, discrete-state Markov process has been used to predict geological conditions. The Monte-Carlo (MC) simulation (MCS) method is employed to estimate the construction time and costs of a road tunnel project using the input data obtained from six tunneling expert questionnaires. In the first case, the input data obtained from each expert are individually considered and in the second case, they are simultaneously considered. Finally, a comparison of these two modes based on the technique presented in this article suggests considering views of several experts simultaneously to reduce uncertainties and ensure the results obtained for geological conditions and the construction time and costs.

소규모 시공현장 적정공사비 확보를 위한 원가기준 마련 연구 (A Study on Cost Standards for Securing Appropriate Construction Costs for Small-Scale Construction Sites)

  • 오재훈;안방율
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2023년도 봄 학술논문 발표대회
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    • pp.347-348
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    • 2023
  • In construction sites, small-scale construction quantities or limited work hours below the daily work volume may occur due to on-site conditions. For small-scale quantities, the input of equipment and labor is designed based on an hourly basis in the invoice, resulting in a difference from the actual cost. In this study, we aim to explore solutions from the perspective of construction cost standards to secure appropriate construction costs for small-scale and time-limited construction sites. Firstly, to preserve the basic construction costs on-site, we established standards where half the cost would be charged for construction quantities below four hours and a full day's cost would be designed for construction quantities between four to eight hours. Additionally, realistic construction cost calculation standards are expected to be provided by realizing a surcharge rate for work hour limitations to secure appropriate construction costs.

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RESEARCH OF THE BEST TIMING FOR GOVERNMENT'S TERMINATION OF FREEWAY REPAIR WORK CONTRACT

  • Jin-Fang Shr;Da-Jung Chang
    • 국제학술발표논문집
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    • The 1th International Conference on Construction Engineering and Project Management
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    • pp.699-704
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    • 2005
  • Normally, monetary penalties for breach of agreement will be stipulated in the contract. The contractor parties, who fail to fulfill the agreement, are required to pay the other parties a certain amount or proportion of money as a fine. However, it is worth our study - whether or not the scope of monetary penalty implementation and bases for determination of a fine will cover the losses of social and administrative costs incurred by the interruption of the contract. This research is about the best timing for government to cancel the freeway repair work contracts. Under the goal of the maximum social welfare, the limitation of government spending for the social and administrative costs invoked by interruption of contracts will have to be considered to attain the best timing of contracts' suspension or deferment. According to the factors of social and administrative costs, the best time point is calculated to reduce the loss of the aforesaid costs, which can also be used as theoretical basis for the future road-widening construction at home.

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Cost Analysis of the Structural Work of Green Frame

  • Joo, Jin-Kyu;Kim, Sun-Kuk;Lee, Goon-Jae;Lim, Chae-Yeon
    • 한국건축시공학회지
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    • 제12권4호
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    • pp.401-414
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    • 2012
  • The adoption of Green Frame is expected to provide economic benefits, since construction costs are reduced by the in-situ production of precast concrete column and beam. The cost reduction can ultimately be realized by saving transportation costs and the overhead and profit of PC plants. The cost structure of Green Frame, which is built up using composite precast concrete members, is similar to that of a bearing-wall structure, but the difference in construction process has resulted in some cost differences for a few items. In particular, production and installation is the principal work involved in Green Frame made by precast concrete members, while form and concrete work is the principal work for a bearing-wall structure. As such, the rental time and fee for a tower crane should be compared through time analysis. To verify reliability, this study focused on developed residential projects to estimate the construction costs. Through this analysis, it was found that the costs of Green Frame were 1.57% lower than the costs of bearing-wall structure. The results of this study will help in the development of a management plan for the structural work of Green Frame.

신축 공공도서관의 지위적 역할에 따른 규모와 지역 특성에 따른 건립공사비 기준에 관한 연구 (A Study on the Guideline of construction cost according to Size of position and Regional characteristics of New Public Libraries)

  • 이철재;윤지원;이민
    • 한국실내디자인학회논문집
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    • 제26권3호
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    • pp.113-120
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    • 2017
  • As the functions and roles of public libraries expand, it is time for qualitative growth. In order to improve the quality of public libraries, it is important to plan actual construction costs through systematic feasibility study. Therefore, the purpose of this study is to present the guideline of construction costs considering the size and regional characteristics according to the status role of the new public libraries. The construction costs are based on actual data. The results of the study are as follows. First, we derived the analysis framework according to the size and regional characteristics. The status role of the public libraries was considered theoretically. The size was classified according to status role of the public libraries. Regional characteristics were classified through literature review. Through this, an analysis framework was derived according to size and region. Second, the actual data on construction costs of the new public libraries were examined and analyzed. Basic factors, size, area, and construction costs were analyzed for 285 libraries nationwide that opened from 2010 to 2016. The data of 129 newly opened public libraries were classified. To present construction costs depending on price fluctuation, construction cost index was analyzed as of September 2016. Third, a guideline of construction costs for new public libraries was suggested. The construction cost per $1m^2$ of building area was analyzed. By multiplying 116.70(p), the construction cost index, the construction cost per $1m^2$ of total building area was calculated to be 2,472,350 won. When applying the research result, construction costs can be gained by adding construction cost index of the month.

A risk-based framework for design of concrete structures against earthquake

  • Hassani, Mohammadhassan;Behnam, Behrouz;Maknoon, Reza
    • Computers and Concrete
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    • 제25권2호
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    • pp.167-179
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    • 2020
  • Optimal design of structures against earthquake loads is often limited to reduce initial construction costs, while the cost induced to structures during their useful life may be several times greater than the initial costs. Therefore, it is necessary to consider the indirect costs due to earthquakes in the design process. In this research, an integrated methodology for calculating life cycle cost (LCC) of moment-resisting concrete frames is presented. Increasing seismic safety of structures and reducing human casualties can play an important role in determining the optimal design. Costs incurred for structures are added to the costs of construction, including the costs of reconstruction, financial losses due to the time spent on reconstruction, interruption in building functionality, the value of people's life or disability, and content loss are a major part of the future costs. In this research, fifty years of useful life of structures from the beginning of the construction is considered as the life cycle. These costs should be considered as factors of calculating indirect costs of a structure. The results of this work represent the life cycle cost of a 4 story, 7 story, and 10 story moment-resisting concrete frame by details. This methodology is developed based on the economic conditions of Iran in 2016 and for the case of Tehran city.

APPLICATION OF FUZZY LINEAR PROGRAMMING FOR TIME COST TRADEOFF ANALYSIS

  • Vellanki S.S. Kumar;Mir Iqbal Faheem;Eshwar. K;GCS Reddy
    • 국제학술발표논문집
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    • The 2th International Conference on Construction Engineering and Project Management
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    • pp.69-78
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    • 2007
  • In real world, the project managers handle conflicting goals that govern the use of resources within the stipulated time and budget with required quality and safety. These conflicting goals are required to be optimized simultaneously by the project managers in the framework of fuzzy aspiration levels. The fuzzy linear programming model proposed herein helps project managers to minimize total project costs, completion time, and crashing costs considering indirect costs, contractual penalty costs etc by practically charging them in terms of direct cost of the project. A case study of bituminous pavement under construction is considered to demonstrate the feasibility of applying the proposed model for optimization of project parameters. Consequently, the proposed model yields an efficient compromise solution and the decision maker's overall degree of satisfaction with multiple fuzzy goal values. Additionally, the proposed model provides a systematic decision-making framework, enabling decision maker to interactively modify the fuzzy data and model parameters until a satisfactory solution is obtained. The significant characteristics that differentiate the proposed model with other models include, flexible decision-making process, multiple objective functions, and wide-ranging decision information.

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ASSESSMENT OF THE COST OF UNDERGROUND FACILITIES OF A HIGH-LEVEL WASTE REPOSITORY IN KOREA

  • Kim, Sung-Ki;Choi, Jong-Won
    • Nuclear Engineering and Technology
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    • 제38권6호
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    • pp.561-574
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    • 2006
  • This study presents the results of an economic analysis for a comparison of the single layer and double layer alternatives with respect to a HLW-repository. According to a cost analysis undertaken in the Korean case, the single layer option was the most economical alternative. The disposal unit cost was estimated to be 222 EUR/kgU. In order to estimate such a disposal cost, an estimation process was sought after the cost objects, cost drivers and economic indicators were taken into consideration. The disposal cost of spent fuel differs greatly from general product costs in the cost structure. Product costs consist of direct material costs and direct labor and manufacturing overhead costs, whereas the disposal cost is comprised of construction costs, operating costs and closure costs. In addition, the closure cost is required after a certain period of time elapses following the building of a repository.

교량의 재가설 공사기간에 따른 사용자비용 평가 (User Costs Evaluation due to the Bridge Reconstruction Period)

  • 김상효;박세준;이동호;안진희
    • 한국구조물진단유지관리공학회 논문집
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    • 제15권1호
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    • pp.148-158
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    • 2011
  • 교량구조물은 사회물류흐름에 필요한 중요한 역할을 하는 사회간접시설물로 공용수명이 다하거나 지진, 폭풍 등의 자연재해에 따라 구조물의 손상이 발생할 경우 기존 교량을 철거하고 재가설 하여야 한다. 공용중인 교량을 재가설할 경우, 차량의 우회, 교통체증에 따른 사용자비용과 공사기간동안의 소음, 분진 등에 따른 사회비용이 발생하게 된다. 하지만 교량의 재가설에 따른 사용자비용과 사회비용은 교량건설시 고려되지 않고, 이를 평가하는 방법 또한 모호하므로 이를 적용한 교량형식이 선정되지 못하고 있다. 따라서 본 연구에서는 교량의 재가설시 발생되는 사회적 간접비용, 즉 사용자의 사회적, 경제적 가치를 파악하여 교량 재가설에 따른 사용자비용의 평가방법을 제안하고 이를 평가하였다. 사용자비용의 평가 시 교량의 일교통량, 첨두시간, 우회거리, 우회시간 등을 포함한 교통정보와 사회적 물동량이 고려되었으며, 차량운행비용과 교량 재가설에 따른 시간지연비용 또한 고려되었다.

런던아이의 디자인 전개와 건립과정에 관한 연구 (A Study on the Design Development and Construction Process in British Airways London Eye)

  • 우대성
    • 건축역사연구
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    • 제15권1호
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    • pp.7-27
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    • 2006
  • This study aims to identify and analyze the factors that influenced the construction of London Eye which was led by private groups, including characteristics in progress, differentiated value in design, the combination of technology and design, and construction costs. The results of this study were the followings. 1) London Eye provides a new construction method for a landmark in the downtown in that the architects became the clients of the project which might have been hoarded, procuring the construction costs and completing it by themselves. 2) London Eye presents a space utilization method where undeveloped spaces in the downtown are used in three-dimensions by erecting a structure on the river with a minimum land. 3) The process of design, production and erection is propelled the realization of technical intention design with one system and from at the initial stage, the participation of the engineer where the designer is equal with you must accompany. 4) London Eye is endowed with strong shape by a circle in design concept, which is the simplest geometrical figure, and it provides organic relationship between the past and the present by utilizing historical elements in various ways. 5) The construction was completed through four phases including idea phase, promotion phase, turn-key contract phase, and design-build phase. The most critical factor to the success is derived from the direct contact with Involved companies from the production phase. 6) In a project facing many challenges in terms of technology, the design-build method proves to be a more effective method than turn-key contract in that it may more allocate risks and enable coherent implementation of the core concept in design. The organization for the design-build method was composed of three phases including general affairs, responsible contracting by sector, and cooperative system by sector. Since that was a new concept structure, high-level contractors who hadn't had existing cooperative relationships with one another formed new cooperative relationship, while collaborating companies who had long cooperated led the responsible contracting and sub-cooperative system, which resulted in reduction of risks and time. 7) The major factors to change design were the design characteristics, derived from a technically great combination, and the opening time. 8) A new erection method was applied to London Eye, a structure that overcame the limitation in land and period, and the process of installation demonstrated that it is an important value for the construction of a landmark in the city. 9) In spite of many visitors and tremendous operational income, the factors that London Eye fails to free itself from debts include the construction costs expended double than expected, and interest burden to the investments, which occurred in the course of procuring the costs. Absolute limit in time increased the construction costs, resulting in being a great obstacle in the course of operation.

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