The value of flexibility and sequential decision-making in maintenance strategies of infrastructure systems

Zuluaga, Santiago; Sánchez-Silva, Mauricio

doi:10.1016/j.strusafe.2019.101916

Cited by 14 publications

(3 citation statements)

References 21 publications

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“…In its essence, damage diagnostics and the subsequent planning of required maintenance is an optimization problem that must find a sufficient balance between the cost of maintenance and the required level of safety of the tunnel. Different strategies to optimize maintenance are presented in the literature, see, e.g., Ai and Yuan [ 76 ], Baji et al [ 77 ], and Zuluaga and Sánches-Silva [ 78 ]. Regardless of the methodology used, the problem is determining suitable threshold values for the observed damage to decide if any countermeasures need to be taken or if the damaged section does not impact the structural stability or safety and can be ignored.…”

Section: Assessment Of the Safety Of Damaged Concrete Liningsmentioning

confidence: 99%

Towards Automated Inspections of Tunnels: A Review of Optical Inspections and Autonomous Assessment of Concrete Tunnel Linings

Sjölander

Belloni

Ansell

et al. 2023

Sensors

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In recent decades, many cities have become densely populated due to increased urbanization, and the transportation infrastructure system has been heavily used. The downtime of important parts of the infrastructure, such as tunnels and bridges, seriously affects the transportation system’s efficiency. For this reason, a safe and reliable infrastructure network is necessary for the economic growth and functionality of cities. At the same time, the infrastructure is ageing in many countries, and continuous inspection and maintenance are necessary. Nowadays, detailed inspections of large infrastructure are almost exclusively performed by inspectors on site, which is both time-consuming and subject to human errors. However, the recent technological advancements in computer vision, artificial intelligence (AI), and robotics have opened up the possibilities of automated inspections. Today, semiautomatic systems such as drones and other mobile mapping systems are available to collect data and reconstruct 3D digital models of infrastructure. This significantly decreases the downtime of the infrastructure, but both damage detection and assessments of the structural condition are still manually performed, with a high impact on the efficiency and accuracy of the procedure. Ongoing research has shown that deep-learning methods, especially convolutional neural networks (CNNs) combined with other image processing techniques, can automatically detect cracks on concrete surfaces and measure their metrics (e.g., length and width). However, these techniques are still under investigation. Additionally, to use these data for automatically assessing the structure, a clear link between the metrics of the cracks and the structural condition must be established. This paper presents a review of the damage of tunnel concrete lining that is detectable with optical instruments. Thereafter, state-of-the-art autonomous tunnel inspection methods are presented with a focus on innovative mobile mapping systems for optimizing data collection. Finally, the paper presents an in-depth review of how the risk associated with cracks is assessed today in concrete tunnel lining.

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Section: Assessment Of the Safety Of Damaged Concrete Liningsmentioning

confidence: 99%

Towards Automated Inspections of Tunnels: A Review of Optical Inspections and Autonomous Assessment of Concrete Tunnel Linings

Sjölander

Belloni

Ansell

et al. 2023

Sensors

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“…Over the past few years, there have been quite a few interesting studies that examined the value of flexibilities embedded in the sequential decision-making process of maintenance and rehabilitation along a given analysis horizon. These include, for example, Swei et al (2019), van den Boomen, Spaan, Shang, and Wolfert (2020), and Zuluaga and Sánchez-Silva (2020). Different from the previous real options studies, these studies commonly adopted dynamic programming to address the sequential decision-making issue.…”

Section: Valuation Of Maintenance Flexibilitiesmentioning

confidence: 99%

Towards an Evidence-Based Value-for-Money Assessment Methodology: Consideration of Innovation, Flexibility, and Risks in Public-Private Partnerships

Zhang

2023

Preprint

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Public-private partnerships (PPPs) have been advocated as an effective delivery model that promotes innovation, flexibility and efficient risk allocations. Value for Money (VfM) assessment is a crucial decision-supporting tool in the developing process. However, the current assessment methods suffer from subjectivity and ambiguity. The thesis documents the doctoral research in developing an integrated probabilistic VfM assessment framework that characterizes the interaction among innovations, flexibility, and risks in PPPs based on multiple research methods including personal interview, empirical data analysis, analytical model and framework development. The study consists of four major pieces, each representing a published or to-be- published journal article. The first paper deals with empirical evidences of the use of engineering innovations in Canada’s PPP market. Personal interview was employed in the study. The empirical evidence proves that PPPs does provide unique innovation opportunities and scope. The second paper presents a direct comparative analysis between traditional and PPP projects by tracking the cost and schedule performance data in Canadian market. The research demonstrates that PPPs outperform traditional models on cost and schedule performance during the construction stage. The third paper presents a stochastic modelling methodology to evaluate the lifecycle cost risk considering maintenance flexibility, characterizing the complex interaction among the lifecycle cost, performance deterioration, and maintenance strategies. Simulation-based optimization and dynamic programming analysis are used to determine the probability distributions of the lifecycle cost and the VfM. The study shows that the lifecycle cost risk is not fully transferred to the private party. Finally, the fourth and last paper integrates the results from the previous three papers and develops a probabilistic VfM assessment framework to incorporate interaction between value drivers and uncertainty sources based on empirical evidences. A new VfM assessment paradigm using the probability of negative VfM as the decision criterion is recommended. The proposed VfM framework makes use of the best empirical evidences available, and when empirical data are not available, some credible analytical models to quantify the value and risks associated with the value drivers. The proposed framework has painted a clear road map to enhance the objectivity and validity of the VfM assessment.

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“…Current large-scale infrastructure projects are experiencing major delays, cost overruns, and inefficiency [10]. Zuluaga pointed out that flexibility in decision-making was important in infrastructure development [11]. Therefore, there is an urgent need to find an effective method to guide the development of NIs.…”

Section: Introductionmentioning

confidence: 99%

Decision-Making Based on Network Analyses of New Infrastructure Layouts

Wang

Zhang

et al. 2022

Buildings

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New Infrastructure (NI) has gradually become a new driving force for regional economic growth and an important part of the construction of new urban infrastructure in many countries, including China. Compared with traditional infrastructures, these NIs have mutually supportive functions and complex interrelationships that create interconnected networks of resources, information, and other interactions during the construction of the NIs. Therefore, it is important to analyze such correlation networks and explore their formation mechanisms in order to develop more scientific and reasonable strategies for NI investment and construction. In this study, the interdependence between NIs in Chongqing was analyzed as an example. Social network analysis (SNA) was used for the overall characteristics of the interdependency network of the NIs and an exponential random graph model (ERGM) was used to reveal the formation mechanism of this network. The results showed that information infrastructure is the key node for enhancing the effectiveness of Chongqing’s NI needs and its government should play a coordinating role. The network of related relationships is characterized by “reciprocity” and “small group”. The aggregation of NIs with such characteristics can produce an agglomeration effect. So, in the planning of NIs, the coordination among management departments should be strengthened and project locations should be reasonably arranged according to the functional interactive characteristics of the projects.

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The value of flexibility and sequential decision-making in maintenance strategies of infrastructure systems

Cited by 14 publications

References 21 publications

Towards Automated Inspections of Tunnels: A Review of Optical Inspections and Autonomous Assessment of Concrete Tunnel Linings

Towards Automated Inspections of Tunnels: A Review of Optical Inspections and Autonomous Assessment of Concrete Tunnel Linings

Towards an Evidence-Based Value-for-Money Assessment Methodology: Consideration of Innovation, Flexibility, and Risks in Public-Private Partnerships

Decision-Making Based on Network Analyses of New Infrastructure Layouts

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