• Korean Journal of Construction Engineering and Management
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• v.19 no.6
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• pp.86-93
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• 2018

Infrastructure which mandatory in human life causes large environmental loads when they are being installed and maintained. Especially, maintenance is performed over a long period of time. Also, there is a limit to suggest a reliable estimated value because environmental loads are changed according to methods of maintenance and periods. In this study, we developed a Environmental Load Estimating Model to evaluate value and plan as soon as possible in the Early Design Phases while maintaining a tunnel. To estimate environmental loads by using brief design information, we analyze a calculation methodology of environmental loads in maintenance phases. Furthermore, we apply periods of maintenance work and maintenance factors considered a characteristic of long-term maintenance. Finally, a main purpose is that this program makes all users estimate environmental loads in maintenance phases easily and quickly. Accordingly, it is considered that the Environmental Load Estimating Model offer assistance to eco-friendly maintenance of the road and tunnel construction.

• International conference on construction engineering and project management
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• 2007.03a
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• pp.837-847
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• 2007

The study focused on the evaluation of maintenance management strategies used in public hospital buildings in Lagos state. It also assessed the labour composition for maintenance operations. In achieving these objectives, opinions of maintenance officers of ten (10) different hospitals in different local government areas of the state were sampled through well structured questionnaires. The data collected were analyzed using descriptive and inferential statistics. From the analysis, the study revealed that majority of those public hospitals do not have specific budget for maintenance programmes, maintenance policies, maintenance log book and maintenance manual to guide the operatives. About 98% of them do not understand the type of maintenance strategy being used for their maintenance operations. 78% of the maintenance work are only executed when there is a breakdown or in response to user's request. For labour composition, the cleaning of interior and exterior of the building, inspection of building elements, repairs and replacements of building elements are mainly carried out by in-house staff, while the repair and replacement of equipment is by outsourcing. The study also revealed that using in- house staff, reduces costs and provides a higher security while outsourcing provides more flexibility in staffing reduces equipment expenditures and provide better access to special skills. The study recommended proactive measures to provide necessary training and support for maintenance staff and users of these facilities and a means of securing sufficient funds for maintenance programmes.

• Smart Structures and Systems
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• v.4 no.5
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• pp.641-653
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• 2008

This paper proposes a practical and realistic method to establish an optimal lifetime maintenance strategy for deteriorating bridges by considering the life-cycle performance as well as the life-cycle cost. The proposed method offers a set of optimal tradeoff maintenance scenarios among other conflicting objectives, such as minimizing cost and maximizing performance. A genetic algorithm is used to generate a set of maintenance scenarios that is a multi-objective combinatorial optimization problem related to the lifetime performance and the life-cycle cost as separate objective functions. A computer program, which generates optimal maintenance scenarios, was developed based on the proposed method using the life-cycle costs and the performance of bridges. The subordinate relation between bridge members has been considered to decide optimal maintenance sequence and a corresponding algorithm has been implemented into the program. The developed program has been used to present a procedure for finding an optimal maintenance scenario for steel-girder bridges on the Korean National Road. Through this bridge maintenance scenario analysis, it is expected that the developed method and program can be effectively used to allow bridge managers an optimal maintenance strategy satisfying various constraints and requirements.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.1
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• pp.51-62
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• 2017

For the asset management of a water pipe network, it would be necessary to understand the extent of the maintenance cost required for the water pipe network for the future. This study would develop a method to draw the optimum cost required for the maintenance of the water pipe network in waterworks facilities to maintain the aim revenue water ratio and to achieve the target revenue water ratio, considering the water service providers' waterworks condition and revenue water ratio comprehensively. This study conducted a survey with 96 water service providers as of the early 2015 and developed models to estimate the optimum maintenance cost of the water pipe network, considering the characteristics of the water service providers. Since the correlation coefficient of all the developed models was higher than 0.95, it turned out that it had significant reliability, which was statistically significant. As a result of applying the developed models to the actual water service providers, it was drawn that increasing revenue water ratio to more than a certain level can reduce the maintenance cost of the water pipe network by a great deal. In other words, it is judged that it would be the most efficient to secure the reliability of waterworks management by increasing the short-term revenue water ratio to more than a certain level and gradually increase the revenue water ratio from the long-term perspective. It is expected that the proposed methodology proposed in this study and the results of the study will be used as a basic research for planning the maintenance of water pipe network or establishing a plan for waterworks facilities asset management.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.3
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• pp.41-52
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• 2020

This paper investigates the stress-reducing preventive maintenance model through numerical experiments. The preventive maintenance model is used to analyze the relationship between related conditions and variables to gain insight into the efficient operation of the system when performing preventive maintenance in real-world situations. Various preventive maintenance models have been developed over the past decades and their complexity has increased in recent years. Increasing complexity is essential to reflect reality, but recent models can only be interpreted through numerical experiments. The stress-reducing preventive maintenance is a newly introduced preventive maintenance concept and can only be interpreted numerically due to its complexity, and has received little attention because the concept is unfamiliar. Therefore, for information purposes, this paper investigates the characteristics of the stress-reducing preventive maintenance and the relationship between parameters and variables through numerical experiments. In particular, this paper is focusing on the economic feasibility of stress-reducing preventive maintenance by observing changes in the optimal preventive maintenance period in response to changes in environmental stress and the improvement factor. As a result, when either the environmental stress or the improve effect of stress-reducing preventive maintenance is low, it is not necessary to carry out the stress-reducing preventive maintenance at excessive cost. In addition, it was found that the age reduction model is more economical than the failure rate reduction model.

• Journal of Korean Society on Water Environment
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• v.36 no.1
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• pp.29-35
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• 2020

To manage the non-point source pollution and restore the water circulation, many technologies including infiltration or reservoir systems were installed in the urban area. These facilities have many problems regarding maintenance as their operation period becomes lengthier. The purpose of this study was to estimate the optimal maintenance timing through a long-term load test on the infiltration trench as one of the low impact development techniques. An infiltration trench was installed in the demonstration test facility, and stormwater was manufactured by Manual on installation and operation of non-point pollution management facilities from the Ministry of Environment, Korea and entered into the infiltration trench. Particle size distribution (PSD), suspended solids (SS) removal efficiency, and infiltration rate change tests were performed on inflow and outflow water. In case of the PSD, the maximum particulate size in the outflow decreased from 64 ㎛ to 33 ㎛ as the operating duration elapsed. The SS removal efficiency improved from 97 % to 99 %. The infiltration rate changed from 0.113 L/sec to 0.015 L/sec during the operation duration. The maintenance timing was determined based on the stormwater runoff requirements with these changes in water quality and infiltration rate. The methodologies in this study could be used to estimate the timing of maintenance of other low impact development techniques.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.12
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• pp.1051-1070
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• 2009

• Journal of Environmental Impact Assessment
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• v.21 no.1
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• pp.93-104
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• 2012

In this research LCA methodology was adapted and analyzed in quantifying estimation of estuarine environment. The analysed objects of estuarine environment were construction methods, facility, and input material into water, and estuarine ecosystem. In this research the function of LCA of estuarine environment was river with the view of controling water, utilizing water, and hydrophilic function. According to the result of research, environmental damage indicator of facility was decreased 346 Pt from 453 Pt at pre-maintenance to 107 pt at post-maintenance. Among raw and subsidiary materials, remicon, stone-netting bag, and pebbles were showing heavy environmental load in the order. Evironmental impact of input material into water system was analyzed from 1,827 Pt environmental load before construction to 1,080 Pt of post-maintenance, and damage indicator was improved at 747 Pt. Water quality was improved from 1,827 Pt (before construction) to 1,080 Pt(after construction), and ecosystem was improved after maintenance. Environmental indicator in ecosystem was analyzed 427 Pt(before construction) to 348 Pt(after construction), and damage indicator of Sumnjingang riverine system was improved as much as 79 Pt. In the conclusion, estuarine environmental monitoring through LCA in the area of facility, input material into water and ecosystem showed that close-to-nature stream was 1,172 Pt better than artificial stream in environmental aspects.

• Journal of environmental and Sanitary engineering
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• v.24 no.1
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• pp.1-12
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• 2009

The various environmental problems that we face on today are basically about environmental quality. Since early 1960s affluent material was produced because of remarkable economic growth by many cooperations. However, for the lack of environmental policy, environmental pollutions has been serious. The central government should transfer the producing and consuming structure to environmental affinity through the regulations for developing Korea as a model of environmental nation which takes an active part in global environmental programme and in which the environment and economy are well harmonized. Moreover, the central government should take the lead in prevention of environmental pollution through the direct policies such as strengthening the discharge limit or setting up environmental basic institutions by securing budget for conserving environment. This thesis emphasize on the public institution among many environmental basic institutions for environmental anti-pollution project. It will find the problems with running those institutions, and will suggest the preview of improvement. Also, it is necessary to investigate of variation trend for inflow and pollutant loading to environmental infrastructure as increased of the diffusion rate as established and maintenance of sewer system. The purpose of this study is to investigate for inflow and pollutant loading to environmental infrastructure, and also to provide the method of efficiently maintenance and management. The results obtained were summarized as follows; 1. Survey of actual condition on operation and management of environmental infrastructure was evaluated the propriety of treatment process and problem of plant management. 2. Analysis of pollutant loading contribution for river system of environmental infrastructure with data analysis of water quality measuring network. 3. To investigate on case study for efficiently maintenance and management of environmental infrastructure. The result on this study was provide the method of efficiently maintenance and management with survey for establish and repair of sewer system and survey of actual condition on operation and management of environmental infrastructure in the water area of discharge to Geum River System. Application as guideline for establish and management of environmental infrastructure, and management of Geum River System. Also, application for preliminary data for fulfill-assess of total effluent regulation of water pollution.

• Journal of Environmental Science International
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• v.30 no.11
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• pp.915-924
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• 2021

Today, as interest in the importance of urban parks increases, many citied internationally are actively creating small parks, but their maintenance systems remain ineffective. Accordingly, in this study, the limitations and problems in the operation and management of urban parks were derived by examining previous studies on overall urban park maintenance and management. Based on this, the study tried to understand the actual state of maintenance and management of small parks through data surveys and field surveys related to budget execution on case sites. Then, we sought to clarify the actual state of maintenance and management of small parks through data surveys and field surveys regarding the budget execution of case sites as a basis for research to prepare an efficient and systematic improvement plan for the maintenance management system of city parks.