• Structural Monitoring and Maintenance
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• v.2 no.2
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• pp.133-143
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• 2015

Civil engineering infrastructure is aging and requires cost-effective maintenance strategies to enable infrastructure systems operate reliably and sustainably. This paper presents an approach for determining risk-cost balanced repair strategy of corrosion damaged reinforced concrete structures with consideration of uncertainty in structural resistance deterioration. On the basis of analytical models of cover concrete cracking evolution and bond strength degradation due to reinforcement corrosion, the effect of reinforcement corrosion on residual load carrying capacity of corroded reinforced concrete structures is investigated. A stochastic deterioration model based on gamma process is adopted to evaluate the probability of failure of structural bearing capacity over the lifetime. Optimal repair planning and maintenance strategies during the service life are determined by balancing the cost for maintenance and the risk of structural failure. The method proposed in this study is then demonstrated by numerical investigations for a concrete structure subjected to reinforcement corrosion. The obtained results show that the proposed method can provide a risk cost optimised repair schedule during the service life of corroded concrete structures.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.3-10
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• 2022

An estimated investment gap of $176 billion needs to be filled over the next ten years to improve America's inland waterway transportation systems. Many of these infrastructure systems are now beyond their original 50-year design life and are often behind in maintenance due to funding constraints. Therefore, long-term maintenance strategies (i.e., asset management (AM) strategies) are needed to optimize investments across these waterway systems to improve their condition. Two common AM strategies include policy-driven maintenance and performance-driven maintenance. Currently, limited research exists on selecting the optimal AM approach for managing inland waterway transportation assets. Therefore, the goal of this study is to provide a decision model that can be used to select the optimal alternative between the two AM approaches by considering key uncertainties such as asset condition, asset test results, and asset failure. We achieve this goal by addressing the decision problem as a single-criterion problem, which calculates each alternative's expected value and certain equivalence using allocated monetary values to determine the recommended alternative for optimally maintaining navigable waterways. The decision model considers estimated and predicted values based on the current state of the infrastructure. This research concludes that the performance-based approach is the optimal alternative based on the expected value obtained from the analysis. This research sets the stage for further studies on fiscal constraints that will effectively optimize these assets condition.

• 한국터널공학회:학술대회논문집
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• 2005.04a
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• pp.292-298
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• 2005

Tunnel in subway should be designed as a water-proof type tunnel as much as possible but it is difficult to make it come true due to several facts, such as construction technique and cost. A drainage type tunnel as a substitute of a water-proof tunnel lead to the increase of water pressure on the concrete lining that make bad effect to tunnel structure when it has some problem to operate the drainage system. Throughout studying about cases on defects of tunnel drainage in subway We hope it contributes to tunnel maintenance.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.1032-1041
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• 2009

그라운드 앵커의 유지관리 점검 목적은 크게 두 가지로 구분된다. 첫째는 기 시공된 앵커 및 앵커 구조물이 설계 의도에 맞게 적절히 작용(기능)하고 있는지를 점검하고 원래 목적한 기능을 수행하도록 보수 보강하기 위함이며, 둘째는 점검결과를 바탕으로 장기적인 운용에 따라 앵커에 발생하는 결함을 보완하도록 유지관리를 고려한 설계에 활용하기 위함이다. 그러나 그라운드 앵커가 도입된 이후 40여년이 지났지만 아직 국내의 실정에 맞는 유지관리의 방안이 마련되어 있지 않은 것이 현실이며, 특히, 장기간 그 기능을 유지해야 하는 영구앵커의 경우는 유지관리가 더욱더 중요한 과제이다. 따라서, 본 연구에서는 그라운드 앵커의 유지관리 점검에 대한 방안을 제안하고자 한다.

• Smart Structures and Systems
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• v.5 no.2
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• pp.173-191
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• 2009

Civil infrastructures are always subjected to various types of hazard and deterioration. These conditions require systematic efforts to assess the exposure and vulnerability of infrastructure, as well as producing strategic countermeasures to reduce the risks. This paper describes the needs for and concept of advanced sensor technologies for risk assessment of civil infrastructure in Japan. Backgrounds of the infrastructure problems such as natural disasters, difficult environment, limited resource for maintenance, and increasing requirement for safety are discussed. The paper presents a concept of risk assessment, which is defined as a combination of hazard and structural vulnerability assessment. An overview of current practices and research activities toward implementing the concept is presented. This includes implementation of structural health monitoring (SHM) systems for environment and natural disaster prevention, improvement of stock management, and prevention of structural failure.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1202-1207
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• 2011

This article introduces the benchmarking methodologies, the results of comparative analysis on the railway electricity maintenance management - preventive maintenance, corrective maintenance, upgrade maintenance. This article also compares the Korean railway electricity maintenance management with the results mentioned above and analyses the situations of each country - France, Germany, Japan. Lastly this article tries to find the comparative position of the Korean railway infrastructure costs and discusses the direction of cost reduction in railway electricity maintenance management.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.717-724
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• 2018

To prepare for the explosive increase in maintenance costs of bridges according to the aging of infrastructure, future maintenance costs of bridges should be predicted. For this purpose, the management status of bridges was investigated and modeled as the upper limit of the performance level and the target management level according to the life cycle. This paper proposes methodologies and procedures for estimating the bridge maintenance costs using two models and existing cost and performance prediction models that consist of unit repair cost model according to the safety score, performance degradation model of bridges, unit reconstruction cost, and average reconstruction time. To verify the applicability, future maintenance costs can be forecasted for specific management agency considering the number of bridges, degree of aging, and current management status. As a result, it is possible to obtain the maintenance cost and safety level of an individual bridge level for each year. In addition, by summing them up to the agency level, the average safety score, ratio of the safety level, inspection costs, repair costs, and reconstruction costs can be obtained. In a further study, the changes in maintenance costs can be analyzed according to the changes in the target management levels using the developed method. The optimal management level can be suggested by reviewing the results.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1528-1533
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• 2009

Infrastructure is provided to the user through long-term project period and large-scale working expenses. Existing facilities are getting old as time goes by. Accordingly, proper maintenance is required and generally more maintenance cost than initial invested cost is needed during life cycle. Therefore, a specific plan that just increases the value of facilities is required by evaluating performance of facilities and inputting minimum maintenance cost. Value engineering that increases the value of object by systemically analyzing Life Cycle Costs and function is actively promoted at the design phase of construction. These efforts can increase the performance of facilities at the maintenance phase of infrastructure. This study is to search how to evaluate the performance of Roadway by utilizing function analysis, as a core part of VE in the maintenance phase. In order to this a new evaluation criteria were proposed by adding an evaluation items to the existing criteria through the research of old documents, status of roadway maintenance and function analysis of VE. The results of this study may promote the effective performance evaluation to determine a resolution of roadway congestion in future. A succeeding study using the proposed evaluation criteria will be required.

• Ecology and Resilient Infrastructure
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• v.3 no.3
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• pp.153-155
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• 2016

• Journal of Korean Association for Spatial Structures
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• v.21 no.3
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• pp.4-8
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• 2021