• Journal of the Korea Institute of Building Construction
• /
• v.16 no.2
• /
• pp.133-140
• /
• 2016

The amount of labor input in a construction project is used as source data to estimate construction cost and to understand the productivity of the construction industry. However, there is a significant difference between the standard of estimation and the actual amount of labor input, and a plan is needed to resolve this problem. For this reason, to establish a system with which the actual amount of labor input can be inputted in a more accurate and simpler manner, a new method is proposed in this study. In the new method, a digital pen is used to minimize the difference from traditional handwriting on paper using a pen, and eliminate the redundant input of information. This study is expected not only to reduce the actual amount of labor input but also to contribute to the productivity of construction cost estimate through the sharing or utilization of the information on the web.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.40 no.2
• /
• pp.69-80
• /
• 1998

The optimal reservoir storage capacity is needed to be determined at the stage of reservoir planning. The reservoir storage capacity should be based on water balance between demand and supply, and meet the water deficity during the growing season. However, the optimal reservoir storage capacity should be determined considering benefit-cost analysis for the project. In this study, Two models are developed. The one is the RSOM(Reservoir Storage Optimization Model), that is consisted by three submodels, MROPER (Modified Reservoir OPERation model), RESICO(REservoir SIze and the construction COst computation) model. And the other is the BECA(BEnefit-Cost Anaysis) model. For model application, three districts, Chungha, Ipsil and Edong were selected. The relative difference of B/C ratio between project planning data and estimation by RSOM is 17.9, 15.0 and 7.3% respectively, which may be applicable for water resources development feasibility planning.

• Journal of the Korea Safety Management & Science
• /
• v.13 no.2
• /
• pp.267-273
• /
• 2011

Since 'The Act on Private Investment of The Infrastructure' was established in 1994, private investment as well as government's investment in transport infrastructure has been active. However investment in transport infrastructure has more risks than others' due to uncertainty both in traffic volume and in construction cost. In the current appraisal procedure of deciding transportation infrastructure investment, instead of risk management, the sensitivity analysis considering only the changes of benefit, cost and social discount rate which are main factor affecting economic feasibility is carried out. Therefore the uncertainty of various factors affecting demand, cost and benefit are not considered in feasibility study. In this study the problems in current investment appraisal system were reviewed. Using Delphi technique the major factors which have high uncertainty in feasibility study were surveyed and then improvement plan was suggested in the respective of classic 4 step demand forecasting method. The range estimation technique was also mentioned to deal with the uncertainty of the future.

• Journal of the Korea Institute of Building Construction
• /
• v.12 no.1
• /
• pp.108-114
• /
• 2012

Escalation method examining the changes in price index has been widely utilized in public construction projects. The previous escalation method determined estimated changes in price based on the average unit price of contract items over a period of time. In relation to this method, the issue has been raised that the fluctuation rates of previous method show different trends compared with other related price indices, as the influence of the small group of contract items with large unit prices overwhelms the others. This research suggested an improved escalation method which estimates the fluctuation rate by examining the changes in CCI (construction cost index) and applies it to the total amount or the partial amount deducted for labor cost in price escalation for previous bid price method. To verify the improvement, a case study is conducted on an educational facility, and the fluctuation rate was estimated in two different base periods (short term, long term). The results over the long term showed similar tendencies to those of related price indices, as well as significant differences in fluctuation rates compared to those of the previous method.

• Korean Journal of Construction Engineering and Management
• /
• v.13 no.1
• /
• pp.67-76
• /
• 2012

There are index adjustment method and item adjustment method in estimation methods for price fluctuation rate of public constructions. A relevant regulation has put item adjustment method as a principle, but in most construction, contract sum adjustment has been made by index adjustment method. Hence, this study, by figuring out width and causes of the gap between index adjustment method and item adjustment method through direct comparative analysis, solved inequality caused by difference between them and suggested a rational way against irrationality of each method. For building operations of public housing construction, a detailed fluctuation rate by index adjustment method and item adjustment method of construction cost elements of the same construction, that is, direct material cost, direct labor cost and historical construction cost was estimated to analyze difference between two adjustments and establish its cause. Across the analysis, it was found that fluctuation rate by item adjustment method was estimated lower than that by index adjustment method and difference between methods for estimating fluctuation rate of quotation unit price and application of index unrelated to construction type and construction nature are main causes of the difference. This study has a significance in that, for smooth contract sum adjustment between contracting parties, it practically proved the real difference between adjustment methods by conducting comparative analysis of the difference in direct correspondence way.

• Korean Journal of Construction Engineering and Management
• /
• v.15 no.5
• /
• pp.3-12
• /
• 2014

With the scale of program management getting larger and complexity, More accurate and precise method for management cost estimate is demanded. However, most of project management cost estimates are based on similar cases and hence can not reflect distinct features of each project. Cost estimate precision is also not up to the standards, and also troublesome to policy-making and budget allocation. Therefore, project typical model for cost estimate of Comprehensive Project Management is developed, and makes it easier to manage level of effort and allocate cost by applying characteristic factor of each project. This study categorized the project package by phase; planning, detailed design, and bid procurement, to develop typical model. And by designating specific level of effort required for each field and rank, the study aims to improve the method for calculating the detailed and objective program cost. Outcome of this study will prevent conflicts between client and contractor, accurately calculate program management contract cost for the client, and become a reference for the contractor to receive rational and practical payments for their work.

• Journal of the Korean Society of Industry Convergence
• /
• v.23 no.1
• /
• pp.57-64
• /
• 2020

The construction market became generally opened to overseas and the domestic construction industry has competed with the international construction enterprise of which technical knowledge is superior. In order to compete with the international construction companies, domestic construction industry needs more continuous promotions on the research and development for improving the level of technique of the construction engineering to meet the international norm. This study aims to suggest the better standards of engineering output such as drawings and specifications to correspond the changing integration system and bidding system in preparation for growing international competition. The study starts with comparison and analyses of domestic and international methods and standards for preparing design drawings. And it continues to delve into actual drawing preparation practices, especially focusing on the ones for road and subway construction. Finally, the study presents a better way of the standardization of the main drawings such as general plan, longitudinal drawing, cross section, structural drawings and temporary structure for new bidding systems of historical cost estimation and whole specification tender and for promotion of international competitiveness.

• Journal of the Korean Society for Advanced Composite Structures
• /
• v.5 no.2
• /
• pp.21-26
• /
• 2014

This paper introduces general concepts of jointless bridges and field construction case of semi-integral bridge with psc girder integrating end-diaphragm. The expansion joints need to satisfy thermal and safety conditions of bridges. General bridges with joints have some problems, which are frequently replacement cycle time from mechanical damage or unstable movement, maintenance cost and more. To solve these problems, Integral Abutment Bridges(IAB) have been applied overseas in the 1930s. In Korea, first IAB was constructed in the early 2000s and precast IAB systems was invented and applied lately. Kyungshin overpass bridge in Incheon is the Semi-IAB constructed, the span length is 2@35=70m and the width is 13.9m. The original plan was to use general joint bridge but design field changed with expectations for advanced economic estimation and maintenance. This changed method of B.I.B bridge construction provided not only workability, construction cost but also safety improvement at the same time.

• Korean Journal of Construction Engineering and Management
• /
• v.8 no.6
• /
• pp.139-149
• /
• 2007

The purpose of this study is to examine the problem of BTL(Build Transfer Lease) projects through comparative analysis on running costs, focusing on primary school, junior and senior high school education facilities, and then to provide useful information on the estimation of running costs by suggesting valid cost criteria. For this, eight schools from A and B consulting firms were sampled from capital region and other areas. Sampled schools were classified into four categories according to school grade, and running cost data are collected and analyzed from relative view points. The results of this study are as follows: 1) running costs which are analyzed by categories show some difference among sub-items, 2) major problems related to running cost prediction of BTL projects are revealed and improvement schemes are suggested for two groups (Owner and Project applicants).

• Korean Journal of Construction Engineering and Management
• /
• v.11 no.3
• /
• pp.125-133
• /
• 2010

Although work-efficiency of construction machinery is a critical factor for estimating its workable-quantity perunit time, the efficiency figure table presented in the Poom-Sam that is used for Construction Cost Estimation of public sectors in Korea is very subjective for practical usage. In order to suggest objective work-efficiency table for a Pump-Dredger, domestic and overseas documentary records were investigated and on-going construction sites were also visited. Moreover, actual work quantities collected from the site visits were compared with the ones calculated based on the Standard Measurement Methods used in Japan. The research found that the table can be revised by means of detailing down by several factors, namely project type, depth of soil, undersea-site shape, and condition on the sea for better estimation of its workable-quantity. The research will be the foundation for applying the rapid development of Construction Equipment and technology to the appropriate cost estimations and the ground work of related studies.