• Korean Journal of Construction Engineering and Management
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• v.12 no.3
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• pp.31-41
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• 2011

The $LCCO_2$ evaluation programs previously developed in Korea involve limitations in establishing strategies of reducing environmental loads to optimal level in a way to put in materials directly after designing. Therefore, this study has the purpose to extract and propose elements required for the establishment of highly accurate system by counteracting swiftly in a method with high energy efficiency over cost at planning stage. To that end, existing $LCCO_2$ evaluation programs in Korea and abroad were compared and analyzed, and in the planning stage, GEM-21P and Carbon-navigator intended for the establishment of building energy performance improving strategy were selected as the evaluation program for survey. On such basis, after comparison and analysis between $LCCO_2$ calculating methods and system structures of the two programs, elements required for system establishment that can evaluate life-cycle environmental loads of building in planning stage were proposed.

• Journal of the Korean Society of Safety
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• v.37 no.5
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• pp.33-41
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• 2022

As the number of automobile registrations increases yearly, parking spaces that are located in downtown areas are increasing, and mechanical parking facilities are also increasing. Therefore, there is a high risk of accidents when installing and repairing a mechanical parking facility. In the preceding six years (from 2012 to 2018), the statistics that pertain to accidental disasters indicated that a total of 137 disaster victims were generated by the construction sector, 33 accidents occurred, and 10 people died. However, only the safety management items pertaining to accidents that occur during maintenance work and the use of the installed mechanical parking facilities are being studied; furthermore, there is no ongoing research with respect to the risk management that is conducted at the construction site. In 2017, the Korea Occupational Safety and Health Agency (KOSHA) announced the "Guidelines for Safe Installation and Maintenance of Mechanical Parking Equipment"; however, it is a safety guideline that is limited to the installation of basic protective equipment and to facility installation. There is no model for mechanical parking facilities that is indicated in the "Risk Assessment Model by Construction Industry Type", which is issued by the Safety and Health Corporation and is widely utilized for risk assessment in the construction industry; moreover, elevator installation work CODE N0: 22 is the only major example of a disaster. In this study, "risk assessment through a focus group interview" was performed, and data was derived from the "risk assessment of Article 41 (2) of the Industrial Safety and Health Act", which reflects the characteristics of the construction industry based on AHP analysis. The results of this study can be utilized for the risk assessment that is conducted during the construction stage of mechanical parking facilities.

• Proceedings of the Safety Management and Science Conference
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• 2002.11a
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• pp.17-23
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• 2002

Value can be defined as function divided by cost. The ultimate goal of VE (Value Engineering) is to simultaneously reduce cost and to enhance function in given projects. In general, there are eight phases (Selection, Investigation, Speculation, Evaluation, Development. Presentation, Implementation, and Audit) to perform VE. This paper presents analysis of important factors for VE in construction fields using QFD (Quality Function Deployment) technique. QFD was introduced in 1972 to help design supertanker in Mitsubish's shipyards in Kob, Japan and formally defined by the American Supplier Institute in 1987 as a system for translating consumer requirements into appropriate company requirements at every stage, from research, through product design and development, to manufacture, distribution, installation, and marketing, sales and services. The objective of this paper is to provide and analyze the trend on the viewpoint of efficient value engineering of field workers. The data are collected by questionnaires. The samples for this study are chosen from 13 companies in Korea during 2 months (2002. 7 ∼ 2002. 8). The results of this study will play an important role not only for the efficient value engineering but also for preparing of life cycle cost analysis.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1083-1088
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• 2004

Several possibilities on the stability analysis of the railroad tunnels passing through the abandoned mining area are considered in this paper. Previous works on the influence zone due to cavities are investigated to study the effect of the safety deterioration near the cavities which are normally unknown to the engineers. Additional works on the numerical analysis of the influential zone are also performed in 3D space. The praximity of railroad tunnel and unexpected cavities is critical to influence the stability of railroad tunnel under construction. Futhermore, the study on the influence of underground condition like joint and faults should be significantly controlled under both design and construction stage.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.497-501
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• 2013

An important decision-making element for the success of housing redevelopment projects is a prediction of the profitability of redevelopment. Risk factors influencing profitability were deduced through a review of the literature about profitability and a risk analysis developed by a survey of maintenance projects. In addition, a profitability prediction depending on the analysis of risk factors is necessary to judge the business feasibility of a project in the planning stages. A profitability prediction model of management and disposal method, which is calculated by proportional rate and which helps estimate contributions to profitability, is proposed to prevent difficulties in business development. The proposed model has the potential to prevent interruptions, reduce the length of projects, generate cost savings, and enable rational decision-making during the project period by allowing a judgment of profitability at the planning stage.

• Journal of the Korea Institute of Construction Safety
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• v.6 no.1
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• pp.7-11
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• 2024

Pump car is an equipment that transports concrete products as needed to the place where they are poured. In order to pour a large amount of concrete in a short period of time, using a pump car is the most efficient in terms of economic efficiency and quality control. However, recently, many casualties have occurred due to boom damage during concrete pouring, so this study suggests that improvements are needed in the equipment manufacturing stage, inspection standards for old equipment, and equipment rental system. The reason is that, as a result of the finite element analysis of the pump car, the significant stress acting at the second stage of the boom and the maximum stress at the top of the boom were found to be 895.39 MPa, and M.S. Since it was evaluated the lowest at 0.04, the need for reinforcement was recognized. And it was confirmed that the 2nd stage boom was the most stressful and vulnerable part of the 1st to 5th stage booms. Therefore, it is necessary to increase the thickness and rigidity of members at the design and manufacturing stage, and to reinforce the steel plates of currently used equipment. In addition, it is urgent to establish a system that makes non-destructive testing mandatory for all general construction machinery and holds inspection agencies responsible for missing boom defects during non-destructive testing and regular inspections.

• Korean Journal of Construction Engineering and Management
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• v.5 no.1 s.17
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• pp.71-79
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• 2004

In the stage of feasibility study of urban rehabilitation projects, the precise forecast of physical and environmental changes has great influence on the further transaction of the projects. However, various important decision makings are made by the experience and intuition of the person-in-charge in practice without the process and method for systematic and quantitative analysis. In spite of various qualitative influent factors on the projects, the feasibility studies are made by the result of economic analysis only, which often lead the projects to the crucial deficit. The main reasons of such a mal-functional transaction are due to the absence of the reasonal procedure of feasibility study and decision making reflecting the characteristics of urban rehabilitation projects. The objective of this paper is to propose feasibility study processes and decision making methods in relation to various influent factors on urban rehabilitation projects in the initial stage. The goal and process of every analysis stage and the pertinent factors and decision makings are analyzed and proposed through the survey of current research, a case study, interview with the professionals. The processes and methods are well applied to improve current problems of feasibility study of urban rehabilitation projects. In addition, the establishment of the analysis goal at three principal stage and a series of reasonable decision makings with pertinent factors to each stage will lead the project to more successful result than ever.

• Advances in concrete construction
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• v.9 no.1
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• pp.55-70
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• 2020

In this research article, acid resistance, sulphate resistance and sorptivity of self compacted concrete (SCC) prepared from C&D waste have been discussed. To improve the above properties of self compacted recycled aggregate concrete (SCRAC) along with mechanical and durability properties, different two stage mixing approaches (TSMA and TSMAsfc) were followed. In the proposed two stage mixing approach (TSMAsfc), silica fume, a proportional amount of cement and a proportional amount of water were mixed in premix stage which fills the pores and cracks of recycled aggregate concrete (RAC). The concrete specimen prepared using above mixing approaches were immersed in 1% concentration of sulphuric acid (H2SO4) and magnesium sulphate (MgSO4) solution for 28, 90 and 180 days for evaluating the acid resistance of SCRAC. Experimental results concluded that the proposed two stage mixing approach (TSMAsfc) is most suitable for acid resistance and sulphate resistance in terms of weight loss and strength loss due to the elimination of pores and cracks in the interfacial transition zone (ITZ). In modified two stage mixing approach, the pores and cracks of recycled concrete aggregate (RCA) were filled up and make ITZs of SCRAC stronger. Microstructure analysis was carried out to justify the reason of improvement of ITZs by electron probe micro analyser (EPMA) analysis. X-ray mapping was also done to know the presence of strength contributing elements presents in the concrete sample. It was established that SCRAC with modified mixing approach have shown improved results in terms of acid resistance, sulphate resistance, sorptivity and mechanical properties.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.521-532
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• 2008

Supporting system design and construction management for the soft and hard rock layers with fractured zones are very important theme for the safety of temporary retaining wall, surrounding ground and structures in the urban deep excavation for the construction of subway, railway, building etc. The prevailing design method of supporting system for the soft and hard rock layers in the deep excavation is mostly carrying out by simplification without proper consideration for the characteristic of rock discontinuities. Therefore the behaviors of rock discontinuities and fractured zones dominate the whole safety of excavation work in the real construction stage, serious disaster due to the failure of temporary retaining wall can be induced in the case of developing large deformations in the ground and large axial forces in the supporting system. This paper introduces examples of deep excavation where the soft and hard rock layers with fractured zones were designed to be supported by shotcrete and rock bolt, deformations of corresponding ground and supporting systems in the construction period and increments of axial force in the upper earth anchors and strut due to the these deformations were investigated through detailed analysis of measurement data, the results were so used for the management of consecutive construction that led to the safe and economical completion of excavation work. The effort of this article aims to improve and develop the technique of design and construction in the coming projects having similar ground condition and supporting method.

• Korean Journal of Construction Engineering and Management
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• v.18 no.4
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• pp.17-26
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• 2017

The sustainable growth of Construction Management(CM) market depends on clients'acceptance from positive project outcomes of CM services. Achieving the positive outcomes requires CM firms'competency and efforts. Equally, it is critical to understand and overcome barriers of CM performance, which cause inefficiencies and under-performance of CM services. The objective of the study is to identify and discuss the barriers of CM performance during pre-construction stages in private CM projects based on the FMEA technique. Major findings basically suggest that clients and CM firms have roles to play, individually and collaboratively, in order to improve CM performance by eliminating performance barriers.