• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.34 no.1
• /
• pp.293-303
• /
• 2014

Recent historical unit price is presented by the Korea Institute of Construction Technology (KICT) and it is analyzed by data from large-scale projects. Therefore it has problem applying to small-scale projects. To indicate the problem, the study compared historical unit price of large-case project and small-case project in the case of civil engineering work, building construction, and mechanical facility work. As a result, average historical unit price of small-scale project was 26.6% higher than large-scale project. On the other hand, difference on the labor cost was 18.4%, difference on material cost and overheads were 8.18%. Moreover, the study proposed compensation method to correct to apply recent historical unit price to small-scale project.

• Journal of the Korea Concrete Institute
• /
• v.17 no.2 s.86
• /
• pp.229-236
• /
• 2005

To cope with increasing requirements of cost reduction, labor saving, and rapid construction, the purpose of this study is to investigate the structural behavior of PSC monolithic and spliced girders. Three tests were conducted on reduced-scale girder specimens having same type. This paper presents the result of experimental studies on the load-deflection behavior in which different joint and amount of tendon as major variables were investigated. The first one used a monolithic girder was arranged with three tendons. The second one used a spliced girder was joined with three tendons after producing five segments. And the third girder was produced in same conditions with the second girder and arranged with additional tendons. The experimental results show the difference of behavior between monolithic and spliced girders.

• Journal of the Society of Disaster Information
• /
• v.8 no.4
• /
• pp.328-335
• /
• 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 the Korea Academia-Industrial cooperation Society
• /
• v.14 no.3
• /
• pp.1073-1080
• /
• 2013

Owing to 88 Olympic, social atmosphere changed to more freely and abundant liquidity, which caused by trade surplus, had led to the surge in real estate prices. Accordingly, The Roh Taewoo government announced the construction of five new towns, Bun-dang, Il-san etc. The Kim Youngsam government had dramatically enhanced the transparency of transactions on real estate field by introducing real-name transaction system. Whereas the Kim Daejung government carried out real estate stimulus package to early recovery from Asian financial cirsis. But, the Roh Muhyeon government conducted strongly suppressing polices. This report want to testify governments' real estate polices and their effectiveness on the real estate market after '90s using VAR model.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.11 no.5
• /
• pp.99-106
• /
• 2007

To satisfy with the increased requirements of cost reduction, labor saving, and rapid construction, the purpose of this study is to investigate the structural behavior of PSC monolithic and spliced girders. Three tests were conducted on small-scale girder specimens. This paper presents the result of experimental studies in terms of the load-deflection behavior. Different joint type and tendon amount were investigated as major variables. The monolithic girder was arranged with three tendons. The spliced girder consisted of five segments connected by three tendons. In addition, five-segmented girders connected by more than three tendons were built to examine the effect of the tendon amount. The experimental results show the difference of behavior between monolithic and spliced girders. Moreover, nonlinear finite element method analysis was utilized to verify the experimental result.

• Korean Journal of Construction Engineering and Management
• /
• v.21 no.2
• /
• pp.98-106
• /
• 2020

Conventional method of PHC pile head cutting work has several challenges with regard to safety, convenience, productivity, and quality. To address such problems, a prototype of the all-in-one attachment-based PHC pile cutting robot is developed(Yeom, 2018). The Primary objective of this study are to develop a final prototype of all-in-one attachment-based PHC pile cutting robot and to analyze technical feasibility and field applicability of final prototype. According to the technical feasibility and field applicability analysis result, at least 74.2% of the respondents are selected positive answer about technical feasibility of the final prototype, at least 66.6% of the respondents are selected positive answer about field applicability of the final prototype. It is expected that when deployed onsite, the final prototype can not only increase the practical use but also improvement the work safety and productivity of work at the PHC pile head cutting job site.

• Journal of the Korea Institute of Building Construction
• /
• v.17 no.4
• /
• pp.377-384
• /
• 2017

It is generally acknowledged that subcontractors mostly allocate their resources to project relying on their previous experiences, instead of data-based judgement. Installing residential fire protection systems, typically performed by subcontractors, is labor-intensive job and its schedule is frequently changed as the contractor master schedule is often revised. Nevertheless, it is still important for subcontractors to make much effort to improve labor productivity through a thorough planning for scheduling and resource allocation. The purpose of this study is to identify significant factors that affect labor productivity for residential fire protection system installation. For this purpose, 50 potential factors that may affect productivity were identified based on literature reviews and expert interviews. These factors were further explored using correlation analysis and ANOVA test. The results showed that the labor productivity is significant impacted by various project characteristics.

• Korean Journal of Construction Engineering and Management
• /
• v.17 no.2
• /
• pp.135-145
• /
• 2016

In Korea, a series of noise-reduced aluminum forms are being recently used in apartment housing construction. However, their complicated and time-consuming work processes, and the noise which is still generated due to the inherent property of aluminum when especially installing and dismantling them have been pointed out as a problem to be certainly solved for increasing their practical use in construction sites. The primary objectives of this study are proposing an optimal conceptual design of a newly designed noise-reduced aluminum form and verifying the technical feasibility by conducting a working mock-up drive experiment. Thus, conventional noise-reduced aluminum forms have been analyzed and three conceptual designs of a newly noise-reduced aluminum forms have been deducted. AHP has been applied to a survey data collected by interviewing field experts. A trade-off analysis results have shown that 'Noise-reduced System Aluminum Form with a Drop-down Floor Post and Adaptive Beam' the highest weights of safety(0.52), work convenience(0.54) and thus selected. The suggested conceptual design in this study improved problems of conventional system aluminum forms. It is also expected that the suggested design will be used as a reliable guideline for the actual development of an aluminum form that ensures noise-reduce, work convenience and labor safety.

• Korean Journal of Construction Engineering and Management
• /
• v.19 no.6
• /
• pp.124-134
• /
• 2018

Despite the many advantages of modular housing, low preference for modular housing for consumers who are familiar with RC structure leads to high construction cost of modular housing. The cost of modular buildings is about 130% of that of RC structures, so it is urgent to secure economical efficiency of modular buildings. Therefore, in this study, after calculating the savings amount of modular housing by type of construction work, economic analysis was conducted from a long - term perspective. In order to carry out the research, the authors compiled and analyzed the material cost, labor cost, and expenses incurred by each type of work by reclassifying the statement of the modular housing into the factory production and the site installation. After that, Pareto diagrams were created to find a core work that is included in the cost ratio of about 80%, and selected it as a cost reduction subject. Based on the assumption that the market size of domestic modular housing is similar to the level of modular advanced countries such as Japan and European countries, six cost reduction methods were set up that reflects the characteristics of the modular construction method and used for the expert interviews. Cost saving potentials in percentage from the interview were converted to the amount of savings that can be achieved by each type of method when applying the method. Finally, the findings of the study are expected to suggest long-term directions for technical development for modular construction and cost savings.

• Journal of Korean Society of Steel Construction
• /
• v.19 no.1
• /
• pp.15-27
• /
• 2007

Over the past decade, labor costs have increased relative to the cost of material hardware according to analysts in the construction industry. Therefore, the minimum weight design, which has been widely adopted in the literature for the optimal design of steel structures, is no longer the most economical construction approach. Presently, although connection- related costs is crucial in determining the most cost-effective steel structures, most studies on this subject focused on minimum-weight design or engaged in higher analysis. Therefore, in this study, we proposed a fabrication scheme for the most cost-effective moment-resisting steel frame structures that resist lateral loads without compromising overall stability. The proposed approach considers the cost of steel products, fabrication, and connections within the design process. The optimal design considered construction realities, with the optimal trade-off between the number of moment connections and total cost was achieved by reducing the number of moment connections and rearranging them using the combination of analysis that includes shear, displacement and interaction value based on the LRFD code and optimization scheme based on genetic algorithms. In this study, we have shown the applicability and efficiency in the examples that considered actual loading conditions.