Journal of Infrastructure Systems

Managing highway bridge structures in extremely cold regions presents unique problems that are normally not encountered in other climates. Consequently, bridge management systems (BMS) in cold regions have to consider additional criteria in evaluating alternative investment strategies and projects’ selection. In this paper, a method is presented for the vulnerability rating of highway bridges on the structural capacity impacts of climate-triggered extreme loading. Further, the structural capacity rating, along with another recently introduced criterion of vulnerability rating against non-structural-capacity climate-triggered extreme events, together with the two traditional criteria of bridge performance and utility, are combined using a multicriteria, noniterative optimization technique, which is also introduced here for the first time. In addition to the aforementioned new concepts, a major contribution of this paper is the choice of criteria with a view to avoiding prejudgement of the relative importance of one criterion with respect to another as well as the formulation of the criteria weights to render redundant the concept of tradeoffs. As a result, criteria weights are not fixed but vary across the alternative projects. The final output of the new optimization technique is an optimization ranking index (Opt-I), which shows excellent correlation with each project’s probability of being selected for implementation. The new methods are demonstrated using a base of 30 bridge projects from the Canadian Arctic (60° latitude and higher), comprising 10 actual inventory bridges and 20 parametrically derived bridges.

A two-dimensional (2D) time-domain waveform tomography technique is presented for detection of delamination in concrete bridge decks. Measured ultrasonic surface wave fields were inverted using a full waveform inversion (FWI) technique, based on a finite-difference solution of 2D elastic wave equations and Gauss–Newton inversion method. The FWI was applied to both synthetic and real experimental data sets. The real experimental data set was collected on a validation concrete slab using an ultrasonic shear-wave tomography system. The inversion results showed that the waveform analysis was able to delineate delamination zones, including a real delamination at a depth of 80 mm.

Recent advances in the area of modeling systems of systems have brought to the forefront the need to model transportation infrastructure through a new paradigm that would account for the diversity of involved stakeholders, objectives, and interdependencies. This article focuses on a bridge system of systems, and it presents a metamodeling approach in which shared state variables are initially used to link models that represent various subsystems, and subsequently used to provide a tool for coordinating decisions made at the level of the individual subsystems with the goal of obtaining bridge management strategies that are not only optimal from the perspective of a single subsystem, but are more sustainable from a global system of systems perspective.

This study identified longitudinal road roughness limit values based on measured vibration induced in a road-vehicle-driver interaction system. The relations between measured vehicle vibration response and the international roughness index (IRI) were summarized. Frequency-weighted acceleration on the seat and dynamic load coefficient (DLC) were used to quantify ride comfort, ride safety, and the dynamic load of the vehicle and road. Linear relationship coefficients were identified or taken from references. The expected large range of vibration response root mean square (RMS) values was observed for the same level of IRI. IRI limit values were derived for chosen threshold values of vehicle vibration response as a function of vehicle velocity. Velocity-related IRI limit curves were proposed based on the fitting of IRI limit values lower envelope. IRI limit curves were compared with threshold proposals of other authors and width thresholds used in road maintenance. Some of the estimated IRI limit curves for DLC response were below thresholds used for road maintenance.

Water distribution systems, as an urban infrastructure, have an indisputable role in the productivity of a society and the quality of life of its residents. It is necessary to develop policies for evaluation of the urban infrastructure performance and determining the proper time of maintenance and rehabilitation activities to increase system productivity and expand the system’s efficient performance time. In this paper, an algorithm is developed to evaluate the efficiency of urban water infrastructure performance, broken down into costs and benefits, and to determine the optimal time of water distribution network (WDN) rehabilitation using a probabilistic approach. The proposed algorithm is examined in a real water distribution network in Iran. Considering different break scenarios, the WDN’s performance within the projected performance period is simulated. The efficiency of the WDN is quantified using a reliability-based indicator, and costs and benefits of its performance are also evaluated. Based on the estimated reliability of the WDN and its calculated revenue, the actual remaining operation period of infrastructure is determined. A threshold of system revenue to costs ratio can be considered for determining the end of system life span; here 0.5 is considered. Based on the results in the case study, it can be concluded that the efficient lifetime of a WDN can be much less than its designed life span (here the efficient lifetime is 14–16 years, while the design life span is 20 years). The results of this study could be used efficiently in large water distribution networks to determine the rehabilitation time and avoiding the high costs of WDN failure.

Following a major disaster or disruption, the restoration of infrastructure function is often tracked over time. For a more detailed understanding of the recovery process, this paper separates wastewater recovery into multiple service categories. Each service category is further defined by three distinct levels of service: normal, restricted, and no service provision. This proposed format of tracking system recovery allows the functionality to be defined in more detail than commonly presented metrics in the literature while still being conducive to data collection in the immediate recovery following major disruptions. The proposed methodology is applied to the February 22, 2011 Christchurch (New Zealand) earthquake wastewater system recovery. Through this case study, the complexity of wastewater system recovery is evinced along with the future potential for using the suggested breakdown of service and associated metrics. Future application is not restricted to postevent analyses, but also in guiding system recovery during actual events and in planning studies to assess the effectiveness of various redundancies and restoration strategies.

The growing risk of natural and artificial or manufactured hazards combined with a lack of community preparedness have revealed the necessity for comprehensive and effective metrics for evaluating and improving a community’s resilience, i.e., the ability of communities to prepare for, withstand, and recover from disasters. In this paper, the authors review existing community resilience metrics and tools, classifying them into one of three main categories: community-level, sector-specific, or sociological. The paper provides short descriptions of each metric and comparisons across metrics within the three main categories and across classes. The authors assess the strengths and limitations of these metrics, discuss challenges in improving community resilience, and provide recommendations for the development of new measures of resilience. The paper concludes with an outlook on the future of community resilience, particularly the need for metrics that apply across hazards, geographic areas, and factors affecting resilience. The authors propose that effective metrics are characterized by: breadth, measures that address community resilience comprehensively; utility, measures that are able to be utilized by the relevant entities to undertake actions to improve resilience; and scientific merit, measures that are scientifically validated through statistical methods, case studies, and fieldwork.

There is a growing interest in development of performance-related specification for pavement construction. This paper presents the development of performance-related pay adjustments with probabilistic models of pavement performance, with application to in-place air-void contents of asphalt pavements. Quality-assurance data were collected from construction database and pavement-performance data were extracted from pavement-management system. Performance-related pay adjustments were formulated using lifecycle cost analysis considering two different scenarios of maintenance strategy and the variations of pavement overlay life. The results show that the Bayesian approach with Markov-chain Monte Carlo methods can capture unobserved variations in pavement-condition data and relate the quality measure of in-place air-void contents to the expected pavement life with high goodness of fit. The analysis results indicate that there may be significant variations in the model parameters for estimating the expected pavement life due to deviations in acceptance-quality characteristics. This implies that addressing the variations in pavement-performance modeling is a critical issue in deriving performance-related pay adjustments. The probabilistic modeling results facilitate considering the level of reliability in decision making of pay adjustments.

There is a paucity of systematic knowledge on the dynamics of rework in urban renewal projects even though such projects frequently exceed budget and schedule. The causal factors of rework and cost impact on 69 Colombian public projects are examined. The nomenclature of project, organization, and people (POP) is used to categorize causal variables and develop a generic systemic model of rework causation. Inadequate initial budgets, poor project design (which instigated changes during construction), and the social inclusivity of contracts in Colombia (which employ local inexperienced people to conduct the required work) were the most significant contributors of rework. The developed model provides decision makers and stakeholders with insights about the interdependencies and behavior between key influencing variables in Colombian urban renewal projects, and can be used to stimulate learning and process improvements in future projects.

Water main breaks can have significant adverse social, economic, and environmental impacts. As a result, water utilities seek to be proactive and implement asset management programs to reduce the frequency of water main breaks and mitigate their impacts. A key to the success of these asset management programs is the ability to quantify the effect that a variety of factors may have on the likelihood of water main breaks, and hence identify those pipes that need to be inspected frequently. Using water-main break data for a 21-year period from two U.S. cities in the Great Lakes region, this paper demonstrates a methodology to estimate the system-wide monthly frequency of water main breaks as a function of a number of explanatory variables. Using a random-parameters negative-binomial approach, the statistical estimations show that pipe diameters, average pipe age, distribution of pipe age, pipe material, time of year, and mean monthly temperature all have a significant impact on monthly water main break frequencies. The effect that some of these explanatory variables have on break frequencies also varies across months in several cases (as captured by random parameters). Finally, the results clearly show that the relationship between explanatory variables and monthly break frequencies is system specific, as reflected by the many differences in the estimation results between the two water systems considered in this study.

The cured-in-place pipe (CIPP) liner technology involves installation of flexible polymeric composite liners coated with thermosetting resin to the inner surfaces of existing pipelines. This innovative technology provides an efficient, economic, and environmentally friendly method for rehabilitation of structurally compromised underground pipelines without expensive and disruptive excavation. However, the unverified and unquantified seismic performance of CIPP liner-reinforced pipelines under earthquake transient ground deformations (TGD) remains a barrier to the deployment of this technology in seismically active regions. Full-scale quasi-static and dynamic tests were performed on five water-pressurized ductile iron (DI) pipelines, with 150-mm (6.0-in.) nominal diameter and 9.14-m (30-ft) nominal length, reinforced with one type of CIPP liner commonly used in engineering practice. This paper evaluates experimentally the behavior of the liner-strengthened DI pipelines under static loading and also quantifies their seismic response under TGD-induced tensile axial loads. The test results indicate that CIPP liner provides substantial longitudinal tensile stiffness and strength to the joints of DI pipelines and improves significantly their seismic behavior under high-intensity TGD.

Dam overtopping is one of the major causes of dam breach accidents. Many studies have focused on the estimation of dam overtopping probability. However, the occurrence of a dam overtopping incident is subject to many factors including hydrologic and management factors. In this paper, a model for estimating dam overtopping probability considering spillway gate maintenance activity is established based on Bayesian networks (BN). The interactions between factors that can form a loop in causality are decomposed, and the probability representing the feedback effect is calculated for BN construction. The model is applied to an arch dam with three spillway gates. Statistical data and expert domain knowledge are used to quantify the relationships between variables. The results of a case study demonstrate that gate maintenance activity can significantly influence the occurrence probability of dam overtopping. Inspection frequency and individuals’ situational awareness are important factors that need to be enhanced during dam operation. Moreover, the method’s potential as a management tool is illustrated by examining the effect of embedding a reward system.

The detection of corrosion in reinforced concrete structures is one of the primary tasks during inspection. The most common inspection method used is the half-cell potential method. From half-cell potential readings, a judgment is made by allocating investigated structural concrete surfaces to either corrosion detected or corrosion not detected. In this paper, the development of so-called probability of (corrosion) detection (POD) curves is presented. A numerical approach is presented for evaluating the POD in reinforced concrete structures. The probability that a defect, in this case represented by a corroding (anodically acting) area of the reinforcement steel, can be detected was calculated in dependency to electrolytic resistance of concrete, to the concrete cover, and to the grid size chosen for inspection. If parts exposed to different moisture condition are evaluated in one data set, the reliability of corrosion detection can be strongly impaired. If uniformly exposed surfaces are considered, reliable differentiation is possible. The smaller the grid size, the higher the probability that a defect can be detected.

To reduce disruption to traffic during bridge replacement, accelerated bridge replacement (ABR) methodologies are being developed. One of the ABR methodologies being implemented is slide-in bridge construction (SIBC), which reduces the total duration of traffic disruption to less than one or two weekends. Because the SIBC activities are new, the system response is unknown. Quantification of the loads acting on permanent and temporary structures during the slide operation is required to develop recommendations for standardizing SIBC. With this purpose, substructure movements were monitored during an SIBC project in Michigan, USA, and the forces acting on the substructure during the slide operation were back-calculated. Theoretically, forces develop in the sliding direction because of friction, and in the vertical direction because of superstructure weight. However, the analysis results indicated that a force couple developed due differential friction at the sliding surfaces, and resulted in rotating the superstructure and pushing the substructure in the horizontal direction transverse to the slide. Therefore, it is recommended to include monitoring as a task in the project special provisions until the process is standardized.

Prestressed constructions have been extensively used since the 1950s for infrastructure and large-span constructions. During maintenance renovation and after events causing damages, it is often important to know the current stress on the prestressed steel elements of the structure, such as strands or cables. Limited access can often be provided. Then a nondestructive assessment of the current stress is possible. However, several points have to be taken into account before micromagnetic or ultrasound testing methods can be used for determining the current stress value. For both methods, the determination of quantitative values requires a prior calibration. Micromagnetic measurements were performed with the micromagnetic multiparameter microstructure and stress analysis approach developed by Fraunhofer IZFP. It has different sensitivities for microstructure and stress state, but disturbing influences related to microstructure, geometrical effects, temperature, etc. also have to be taken into account. Ultrasound testing for stress determination is based on very accurate time-of-flight (TOF) measurements. The influence of texture of the steel also needs to be considered. Electromagnetic acoustic transducers allow the generation of shear horizontal wave modes, which are optimal to fulfil this requirement. A further advantage is that no couplant is needed and even a small lift off (e.g., due to a coating) is allowed. The paper explains how quantitative stress values can be determined based on micromagnetic and ultrasound testing TOF data recorded in the field and laboratory. Furthermore, a micromagnetic monitoring example is described. Two bundles of bridge cables of a suspension bridge were instrumented with micromagnetic sensors. A loading test was used for verification. The long-term monitoring shows stress changes due to traffic and the renovation of the bridge as well as temperature-induced stress changes in the bridge cables.

The StreetScan pavement-management system (PMS) is introduced. It empowers cities to make more cost-effective road repair decisions. At the heart of the system is a vehicle outfitted with a patented, multimodal sensor array that rapidly collects data for every street in the city. A combination of sensor-specific algorithms and multisensor data fusion are applied to convert the raw data into more actionable condition indices. Decision trees and mathematical models are then applied to determine what repairs are needed and how to prioritize them in the most cost effective manner. Users are able to visualize and interact with the repair suggestions and condition indices through an innovative web-based geographic information system (GIS) application. At less than half the cost, the StreetScan PMS is considerably more affordable than conventional PMSs. This paper validates its effectiveness in the real world by taking a look at two recent applications: (1) a city-wide application in Beverly, Massachusetts and (2) an application to several streets in Boston, Massachusetts.

Social network analysis (SNA) is a well-established methodology for investigating networks through the use of mathematical formulations abstracted from graph theory. It has been successfully used in social sciences to evaluate how individuals and institutions are affected by societal or professional networks, and it has been applied to some civil and construction engineering applications where a network’s main actors are people or organizations controlled by people. Current transportation analysis tools are expensive and time consuming, and require rigorous data for reliable results. Accordingly, a quick and inexpensive methodology to preliminarily analyze traffic networks is beneficial to better direct more detailed transportation analyses. Because of its ability to grasp the full complexity and connectivity of networks in a timely and cost effective manner, SNA can fulfill this requirement. Mathematically speaking, social networks are very close to transportation networks because they share fundamental characteristics. This paper uses SNA to analyze transportation networks and consequently corroborate its effectiveness as a complementary tool for improved transportation planning. To this end, the authors adopted a four-step interrelated research methodology: (1) investigating the connection between the language and concepts of SNA and those of transportation systems; (2) using different SNA centrality measures in the transportation context; (3) using SNA in two case studies in Mississippi; and (4) analyzing the results of the case studies and drawing conclusions. The SNA approach was able to easily and quickly determine the most critical intersections in the investigated transportation networks. These results were in alignment with Mississippi Department of Transportation (MDOT 2014) traffic studies. Using SNA, the research also demonstrated that the performance of central intersections drives the overall performance of the area roadway network. Accordingly, SNA is believed to be an effective and innovative tool in transportation analysis. Using it as an initial analysis step to identify critical areas will assist decision makers in better focusing their more detailed analyses using validated traditional methods in such areas only compared with the entire network. This will significantly decrease the invested resources in transportation planning and will create a more integrated and holistic perspective for evaluating transportation networks.