An overview of the most advanced frameworks for bridge asset management

During this paper it will be discussed some important novelties related to the topic of bridge asset management. In a first step, it will be covered the problematic of bridge assessment through the use of Key Performance Indicators. An emphasis will be made to the outcomes from the COST Action TU 1406 (www.tu1406.eu). Then, it will be discussed how these indicators can be used in the management of existing bridge stock. It will be introduced the problematic of performance predictive models and how maintainability could be integrated for the Life Cycle Cost analysis. At the end it will be discussed the difference between the management of a single and a network of bridges, what type of optimization models and decision-support algorithms can be used. An example is shown through the main results from the research and development project SustIMS – Sustainable Infrastructure Management Systems. The main objective is to show operators how the standardization of this procedure, and how these frameworks would contribute for a more sustainable and efficient management of their bridge stock.This article is based upon the work from COST Action TU1406, Quality specifications for roadway bridges, standardization at a European level (BridgeSpec), supported by COST (European Cooperation in Science and Technology).info:eu-repo/semantics/publishedVersio

Cost Action TU1406: qualitative specifications for roadway bridges: standardization at a european level (BridgeSpec)

Durante la implementación de estrategias de gestión de activos se requieren acciones de mantenimiento para conservar las infraestructuras a un nivel de rendimiento deseado. En el caso de los puentes de carretera, se establecen indicadores de rendimiento específicos para sus componentes que, cuando se combinan, permiten evaluar el rendimiento general. Estos indicadores pueden ser cualitativos o cuantitativos y pueden obtenerse durante inspecciones principales mediante examen visual, ensayos no destructivos o mediante sistemas de vigilancia temporales o permanentes. A continuación, se comparan los indicadores obtenidos con los objetivos de desempeño, para evaluar los planes de control de calidad. En Europa existe una gran disparidad de país a país cuanto a la forma como se cuantifican los indicadores de rendimiento y se especifican los objetivos. COST Action TU1406 pretende reunir, por la primera vez, tanto las comunidades investigadoras como las practicantes, con el fin de establecer una guía europea en esta materia, abordando nuevos indicadores relacionados con el desempeño sostenible y económico de los puentes viales. La aplicación de esta norma dependerá en gran medida de los cambios en la filosofía y los métodos operativos (inspección, ensayos, ...) que las nuevas especificaciones requieren en el futuro como resultado de su aplicación. Por lo tanto, para reducir al mínimo la posible reticencia de las agencias de gestión de carreteras a cambiar los indicadores de rendimiento actuales y los métodos para obtenerlos y también aprovechar los antecedentes, conocimientos y bases de datos existentes, es obligatorio que la nueva especificación de calidad homogeneizada sea más o menos basada en la práctica actual.During the implementation of asset management strategies, maintenance actions are required in order to keep infrastructures at a desired performance level. In case of roadway bridges, specific performance indicators are established for their components which, when combined, allow to evaluate the overall performance. These indicators can be qualitative or quantitative based, and can be obtained during principal inspections through visual examination, nondestructive testing or by temporary or permanent monitoring systems. Then, obtained indicators are compared with performance goals, in order to evaluate if quality control plans are accomplished. In Europe, there is a large disparity from country to country regarding the way performance indicators are quantified and goals specified. COST Action TU1406 aims to bring together, for the first time, both research and practicing communities in order to establish a European guideline in this matter, addressing new indicators related to sustainable and economic performance of roadway bridges. The application of this standard will be highly dependent on the changes in philosophy and operational methods (inspection, testing, …) that new specifications require in the future as a result of their implementation. Therefore, to reduce to a minimum the possible reluctance of highway managing Agencies to change the actual performance indicators and the methods to obtain them and also to take advantage of existing background, knowledge and databases, it is mandatory for the new homogenized quality specification to be more or less based on current practice.This article is based upon the work from COST Action TU1406, Quality specifications for roadway bridges, standardization at a European level (BridgeSpec), supported by COST (European Cooperation in Science and Technology).info:eu-repo/semantics/publishedVersio

Optimal infrastructure maintenance scheduling problem under budget uncertainty

textThis research addresses the infrastructure maintenance scheduling problems under budget uncertainty. Infrastructure agencies usually face budget uncertainties that will eventually lead to suboptimal planning if maintenance decisions are made without taking the uncertainty into consideration. It is important for decision makers to adopt maintenance scheduling policies that take future budget uncertainty into consideration. The author proposes a multistage, stochastic linear programming model to address this problem. The author also develops solution procedures using the augmented Lagrangian decomposition algorithm and scenario reduction method. A case study exploring the computational characteristics of the proposed methods is conducted and the benefit of using the stochastic programming approach is discussed. In the case study, the road network in Dallas District is used with data taken from the Texas Department of Transportation’s Pavement Management Information System. The case study results reveal that the stochastic programming solutions tend to allocate more resources to preventive maintenance than deterministic solutions that ignore the uncertainty information. The proposed methodology can help decision makers effectively obtain optimal maintenance plan under budget uncertainty.Civil, Architectural, and Environmental Engineerin

Multi-objective optimization for time-based preventive maintenance within the transport network: a review

Preventive maintenance in transportation is essential not only to safeguard billions in business and infrastructure investment, but also to guarantee safety, reliability and efficacy within the network. Government, industry and society have been increasingly recognising the importance of keeping transport units condition well-preserved. The challenge, however, is to achieve optimal performance of the existing transport systems within acceptable costs, effective workforce use and minimum disruption. Those are generally conflicting objectives. Multi-objective optimisation approaches have served as powerful tools to assist stakeholders to properly deploy preventive maintenance in industry. In this study, we review the research conducted in the application of multi-objective optimisation for preventive maintenance in transport-related activities. We focus on time-based preventive maintenance for production, infrastructure, rail and energy providers. In our review, we are interested in aspects such as the types of problems addressed, the existing objectives, the approaches to solutions, and how the outcomes obtained support decision

Multi-Scale Methodologies for Probabilistic Resilience Assessment and Enhancement of Bridges and Transportation Systems

When an extreme event occurs, such as an earthquake or a tsunami, the amount of socioeconomic losses due to reduced functionality of infrastructure systems over time is comparable to or even higher than the immediate loss due to the extreme event itself. Therefore, one of the highest priorities of owners, disaster management officials, and decision makers in general is to have a prediction of the disaster performance of lifelines and infrastructures a priory considering different scenarios, and be able to restore the functionality in an efficient manner to the normal condition, or at least to an acceptable level during the emergency, in the aftermath of a catastrophe. Along the line of this need, academic research has been focused on the concept of infrastructure resilience, which reflects the ability of structures, infrastructure systems, and communities to both withstand against and quickly recover functionality after an extreme event. Among infrastructure systems, transportation networks are of utmost importance as they allow people to move from damaged to safe areas and rescue/recovery teams to effectively accomplish their mission. Moreover, the functionality and restoration of several other infrastructure systems and socio-economic units of the community is highly interdependent with transportation network performance. Among different components of transportation networks, bridges are among of the most vulnerable and need a particular attention. To this respect, this research is mostly focused on quantification, and optimization of the functionality and resilience of bridges and transportation networks in the aftermath of extreme events, and in particular earthquakes, considering the underlying uncertainties. The scope of the study includes: (i) accurate\efficient assessment of the seismic fragility of individual bridges; (ii) development of a technique for assessment of bridge functionality and its probabilistic characteristics following an earthquake and during the restoration process; (iii) development of efficient optimization techniques for post-event restoration and pre-event retrofit prioritization of bridges; (iv) development of metrics and formulations for realistic quantification of the functionality and resilience of bridges and transportation networks.The evaluation of the damage and its probabilistic characteristics is the first step towards the assessment of the functionality of a bridge. In this regard, a simulation-based methodology was introduced for probabilistic seismic demand and fragility analyses, aimed at improving the accuracy of the resilience and life-cycle loss assessment of highway bridges. The impact of different assumptions made on the demand was assessed to determine if they are acceptable. The results show that among different assumptions, the power model and constant dispersion assumption introduce a considerable amount of error to the estimated probabilistic characteristics of demand and fragility. The error can be prevented using the introduced simulation-based technique, which takes advantage of the computational resources widely available nowadays.A new framework was presented to estimate probabilistic restoration functions of damaged bridges. This was accomplished by simulating different restoration project scenarios, considering the construction methods common in practice and the amount of resource availability. Moreover, two scheduling schemes were proposed to handle the uncertainties in the project scheduling and planning. The application of the proposed methodology was presented for the case of a bridge under a seismic scenario. The results show the critical impact of temporary repair solutions (e.g., temporary shoring) on the probabilistic characteristics of the functionality of the bridge during the restoration. Thus, the consideration of such solutions in probabilistic functionality and resilience analyses of bridges is necessary. Also, a considerable amount of nonlinearity was recognized among the restoration resource availability, duration of the restoration, and the bridge functionality level during the restoration process.A new tool called “Functionality-Fragility Surface” (FFS) was introduced for pre-event probabilistic recovery and resilience prediction of damaged structure, infrastructure systems, and communities. FFS combines fragility and restoration functions and presents the probability of suffering a certain functionality loss after a certain time elapsed from the occurrence of the extreme event, and given the intensity of the event. FFSs were developed for an archetype bridge to showcase the application of the proposed tool and formulation. Regarding network level analysis, a novel evolutionary optimization methodology for scheduling independent tasks considering resource and time constraints was proposed. The application of the proposed methodology to multi-phase optimal resilience restoration of highway bridges was presented and discussed. The results show the superior performance of the presented technique compared to other formulations both in terms of convergence rate and optimality of the solution. Also, the computed resilience-optimal restoration schedules are more practical and easier to interpret. Moreover, new connectivity-based metrics were introduced to measure the functionality and resilience of transportation networks, to take into account the priorities typically considered during the medium term of the disaster management.A two-level simulation-based optimization framework for bridge retrofit prioritization is presented. The objectives of the upper-level optimization are the minimization of the cost of bridge retrofit strategy, and probabilistic resilience failure defined as the probability of post-event optimal resilience being less than a critical value. The combined effect of the uncertainties in the seismic event characteristics and resulting damage state of bridges are taken into account by using an advanced efficient sampling technique, and fragility analysis. The proposed methodology was applied to a transportation network and different optimal bridge retrofit strategies were computed. The technique showed to be effective and efficient in computing the optimal bridge retrofit solutions of the example transportation network

Study on bridge inspections, A: identifying barriers to new practices and providing strategies for change

2021 Summer.Includes bibliographical references.Bridge inspections are one of the key elements required for a successful bridge management process to ensure adequate bridge performance. Inspections significantly inform maintenance decisions and can help in managing maintenance activities to achieve a reliable bridge network. In the United States (U.S.) routine visual inspections are required for most bridges at a maximum interval of 24-months regardless of the bridge condition. However, limitations of current bridge inspection practices impact the quality of information provided about bridge condition and the subsequent decisions made based on that information. Accordingly, the overarching goal of this research project is to support bridge inspection practices by providing a systematic and rational framework for bridge inspection planning and identifying the factors that can facilitate innovation and research transfer in the bridge inspection field. To do so, this dissertation includes three separate yet related studies; each focusing on essential aspects of bridge inspection planning. Much research in bridge inspection has been conducted to improve the inspection planning process. The first study provides an overview of current bridge inspection practices in the U.S. and conducts a systematic literature review on innovations in the field of bridge inspection planning to identify research gaps and future needs. This study provides a background on the history of bridge inspection in the U.S., including current bridge inspection practices and their limitations, and analyzes the connections between nondestructive evaluation techniques, deterioration models and bridge inspection management. The primary emphasis of the first study is a thorough analysis of research proposing and investigating different methodologies for inspection planning. Studies were analyzed and categorized into three main types of inspection planning approaches; methods that are based on: reliability, risk analysis, and optimization approaches. This study found that one of the main barriers that may be preventing the implementation of new inspection planning frameworks in practice is that the approaches presented focus on a single bridge element or deterioration mechanism in the decision-making process. Additionally, it was concluded that approaches in the literature are either complex to apply or depend solely on expert judgement. Limitations of the uniform calendar-based approach used to schedule routine inspections have been reported in the literature. Accordingly, the objective of the second study is to provide a new systematic approach for inspection planning that integrates information from bridge condition prediction models, inspection data, and expert opinion using Bayesian analysis to enhance inspection efficiency and maintenance activities. The proposed uncertainty-based inspection framework can help bridge owners avoid unnecessary or delayed inspections and repair actions, determine the inspection method, and consider more than one deterioration process or bridge component during the inspection planning process. The inspection time and method are determined based on the uncertainty and risks associated with the bridge condition. As uncertainty in the bridge condition reaches a defined threshold, an inspection is scheduled utilizing nondestructive techniques to reduce the uncertainty level. The framework was demonstrated on a new and on an existing reinforced concrete bridge deck impacted by corrosion deterioration. The results showed that the framework can reduce the number of inspections compared to conventional scheduling methods, while also reducing the uncertainty regarding the transition in the bridge deck condition and repair time. As identified through the first study, over the last two decades many researchers have focused on providing new ideas to improve conventional bridge inspection practices, however, little guidance is provided for implementing these new research products in practice. This, along with resistance to change and complexity of the proposed ideas, resulted in a lack of consistency and success in applying new technologies in bridge inspection programs across state departments of transportation (DOTs). Accordingly, the third paper presents a qualitative study set out to identify the factors that can help improve research products and accelerate change and research transfer in bridge inspection departments. This study used semi-structured interviews, written interviews, and questionnaires for data collection and engaged with twenty-six bridge staff members from different DOTs. The findings of this study are expected to be both specific to changes in bridge inspection practice and have some generalizability to other significant changes to engineering practice at DOTs. To improve research products, this study suggested that researchers need to collaborate more with DOT staff members and provide relevant research products that are not specific to certain bridge cases and can be applied on different bridges. Also, to facilitate change in transportation organizations, change leaders should focus on showing the need for change, gaining support from the FHWA, allocating the required resources, and enhancing the capacity of DOT staff members through training and effective communication. The investigation also presented participants' opinions on some of the aspects related to conventional inspection practices such as their support of a uniform inspection interval over a variable interval, and the main barriers limiting the use of NDE methods. This study contributes to the body of knowledge in the bridge inspection field by providing a new inspection planning approach that depends on the uncertainty and the risks associated with the bridge condition and uses both computational methods and expert judgment allowing bridge owners select inspection time and method while considering more than one deterioration process or bridge element. In addition, this study presents some of the factors that can help reduce the gap between research and practice and facilitate innovation and change in transportation organizations

Life-Cycle Management of Civil and Marine Structures under Fatigue and Corrosion Effects

Infrastructure systems are under continuous deteriorating effects due to various environmental and mechanical stressors. These effects can be generated by sudden threats such as earthquakes, tornadoes, blast, and fire, or gradual deterioration due to fatigue and corrosion. Moreover, as indicated in the 2013 American Society of Civil Engineers (ASCE) Report Card of America\u27s Infrastructure, the United States\u27 infrastructure systems are highly deteriorating with a required estimated investment of 3.6 trillion USD to improve their condition within the next seven years. Given the limited financial resources, rational methodologies are required to support the optimum budget allocation while maintaining maximum possible safety levels. Uncertainties associated with the performance prediction, damage initiation and propagation, damage detection capabilities, and the effect of maintenance and retrofit on the structural performance add more challenges to this allocation process. In this context, life-cycle engineering provides rational means to optimize budget allocation and manage an infrastructure system starting from the initial design and construction to dismantling and replacing the system at the end of its service life.This study provides novel management methodologies which support the decision-making process for civil and marine large-scale structural systems under fatigue and corrosion deterioration. Multi-objective optimization models that seek the optimal trade-offs between conflicting life-cycle management (LCM) aspects such as the life-cycle cost and the projected service life are proposed. These models provide the optimum intervention schedules (e.g., inspections and maintenance actions) which fulfil the LCM goals. For the first time in the field of life-cycle management, an approach capable of establishing the optimum inspection, monitoring, and repair actions simultaneously is proposed. Maximizing the expected service life, minimizing the total life-cycle cost, minimizing the maintenance delay, and maximizing the probability of damage detection are examples of the considered optimization goals. It is shown that the implementation of optimum solutions resulting from the proposed management plans can significantly reduce the life-cycle cost. A methodology for planning inspection actions for bridges with multiple critical fatigue details is proposed. This is considered a step forward from the traditional approaches which are only capable of considering one critical fatigue detail. Additionally, this study provides methodologies for the reliability-based performance evaluation of structures under fatigue deterioration. Furthermore, rational approaches which make use of structural health monitoring (SHM) and non-destructive inspection information for the near real-time decision making for deteriorating structures are proposed. Specifically, an approach to obtain the fatigue reliability of aluminium high-speed naval vessels based on SHM information is proposed. By using the proposed approach, the effect of individual operational conditions encountered by the ship on the overall fatigue damage accumulation can be quantified. This quantification is not possible by using the traditional fatigue life estimation methods. Probabilistic reliability methods and Monte Carlo simulation are implemented to account for uncertainties associated with different aspects of the LCM process. Existing large-scale structural systems are analysed to demonstrate the feasibility and effectiveness of the proposed methodologies