Infrastructures, Volume 7, Issue 7 (July 2022) – 12 articles

The current study aimed to evaluate the influence of different sintering temperatures on the properties of copper aluminum oxide (CuAlO₂) pellets synthesized from copper oxide (CuO) and aluminum hydroxide (Al(OH)₃) for application in smart infrastructure systems. The pellets were sintered at 400 K, 1000 K, and 1300 K, in the presence of nitrogen gas flow to reduce the amount of oxygen availability. The CuAlO₂ sintered nanoparticles were chemically analyzed by X-ray diffractometry, and the nanostructure of the materials was studied by scanning electron microscopy. The transmittance of the sintered materials was examined by ultraviolet/visible (UV/Vis) spectrophotometry, and 88% transparency was observed for the pellets sintered at 1300 K. Electrical conductivity was measured at 0.905 mS/cm, indicating a semiconducting behavior. Full article

This article presents analysis of deterioration indicators for a comparative quantification of the operational structural performances of bridge inventories. The analysis considers the various kinds of material in the entire database of the US National Bridge Inventory. The multi-criteria approach integrates the indicators of deterioration, considering diagnostic condition and life cycle to determine the equivalent operational structural performances. This study also uses reconstruction data to determine an additional deterioration indicator for performance. The proportional effort for reconstruction reflects the practical need to counter deterioration and preserve a required level of structural performance, under all circumstances. The presented addition of reconstruction performance provides a more comprehensive assessment of bridge performance. The results reveal the continuous efforts to maintain a relatively balanced performance adequacy at the national level within the prevailing funding constraints. Reconstruction performances are generally higher than deterioration trends (rate and pattern) performances, revealing that the constrained reconstruction efforts have difficulty to keep pace with the actual deterioration. Full article

The BosWash corridor is a megalopolis, or large urbanized region composed of interconnected transportation, infrastructure, physiography, and sociopolitical systems. Previous work has not considered the BosWash corridor as an integrated, holistic ecosystem. Building on the emerging field of infrastructure ecology, the region is conceptualized here as an infrastructure biome, and this concept is applied to the region’s energy transition to a post-fossil fueled heating sector, in analogy to ecosystem succession. In this conception, infrastructure systems are analogous to focal species. A case study for an energy succession from an aging natural gas infrastructure to a carbon-free heating sector is presented, in order to demonstrate the utility of the infrastructure biome framework to address climate and energy challenges facing BosWash communities. Natural gas is a dominant energy source that emits carbon dioxide when burned and methane when leaked along the process chain; therefore, a transition to electricity is widely seen as necessary toward reducing greenhouse gas emissions. Utilizing an infrastructure biome framework for energy policy, a regional gas transition plan akin to the Regional Greenhouse Gas Initiative is generated to harmonize natural gas transition within the BosWash infrastructure biome and resolve conflict arising from a siloed approach to infrastructure management at individual city and state levels. This work generates and utilizes the novel infrastructure biome concept to prescribe a regional energy policy for an element of infrastructure that has not previously been explored at the regional scale—natural gas. Full article

Crossarms are widely used in power distribution and telecommunication sectors to support overhead cables. These structures are horizontally attached to the top of vertically erected utility poles and are essential elements in connecting overhead cables to the poles. Timber is the dominantly used material type for crossarms in the existing distribution networks. Nevertheless, there are alternative crossarms made from steel, composites, polymers, and even from concrete. This paper reviews the studies on the condition assessment of timber crossarms considering the aspects of decay identification and flexural strength assessment. The limitations and shortcomings of the conventional inspection techniques for crossarms are presented. Then, the studies on the developments of non-destructive test methods to address these issues are reviewed. Further, the results from the experimental work conducted to assess the structural capacity of in-service crossarms are presented and analysed. In addition, the possible future advancements of alternative crossarm types are also discussed, considering the mechanical strength, durability performance, and sustainability aspects. This paper aims to highlight the advantages and disadvantages of different condition assessment techniques for crossarms, indicating the importance of an integrated approach combining both the conventional and non-destructive testing techniques. Full article

In this work, we examine the influence of a crack in the span of a beam as it is being traversed by a point force with constant velocity. This problem presents two types of discontinuities: one spatial, where the crack is modelled as a discontinuity in the slope of the deflection curve of the beam, and a temporal one, with the former derived as the point force moves forward in time. The aim is to interpret time signals registered at a given node on the beam, either during the forced vibration or the free vibration regimes, by using the Gabor transform of the transient beam response so as to observe a pattern that alludes to the location of the discontinuity. Three analytical methods are examined, namely eigenvalue extraction, Laplace transformation and the transform matrix technique. A numerical example is presented using the Laplace transformation, where it is possible to detect the location of damage during the traverse of a point force across the bridge span. Validation studies of the methodology presented here can be conducted in the future, either through field measurements or through experimental setups, which constitutes an important step in realizing applications in structural health monitoring of civil engineering infrastructure. Full article

This study is oriented towards the investigation of the spatiotemporal variability of the lightning activity over the railway network in Sri Lanka using -lightning data from 1998 to 2014 that were downloaded from the database of Lightning Imaging Sensor (LIS) onboard NASA’s Tropical Rainfall Measuring Mission (TRMM). The study has also been extended to study the lightning activity over the proposed suburban railway electrification network. GIS was used to conduct an annual and seasonal analysis of the railway network, which consists of nine major railway lines, to identify vulnerable stations and segments. The average annual lightning flash density over a 1447 km-long railway network of Sri Lanka varies between 5.08–16.58 flashes/(km² year). The railway lines run across the western and southern regions of the country have been identified as being in areas with higher lightning activity. In comparison to other railway lines, the Kelani Valley line in the Colombo district and Colombo-Maradana to Polgahawela segment of the Mainline are particularly vulnerable to lightning activity. These areas have also been recognized as regions with higher population density. The proposed 102 km long railway electrification network in Sri Lanka is also within higher population density segments, with higher lightning flash density values between 10.55–16.53 flashes/(km²⋅year). As a result, to improve the operational efficiency of the proposed electrification network, a fully coordinated lightning protection system in accordance with the findings of this study is strongly suggested. Full article

The fuzzy logic technique is one of the effective approaches for evaluating flexible and rigid pavement distress. The process of classifying pavement distress is usually performed by visual inspection of the pavement surface or using data collected by automated distress measurement equipment. Fuzzy mathematics provides a convenient tool for incorporating subjective analysis, uncertainty in pavement condition index, and maintenance-needs assessment, and can greatly improve consistency and reduce subjectivity in this process. This paper aims to develop a fuzzy logic-based system of pavement condition index and maintenance-needs evaluation for a pavement road network by utilizing pavement distress data from the U.S. and Canada. Considering rutting, fatigue cracking, block cracking, longitudinal cracking, transverse cracking, potholes, patching, bleeding, and raveling as input variables, the variables were fuzzified into fuzzy subsets. The fuzzy subsets of the variables were considered to have triangular membership functions. The relationships between nine pavement distress parameters and PCI were represented by a set of fuzzy rules. The fuzzy rules relating input variables to the output variable of sediment discharge were laid out in the IF–THEN format. The commonly used weighted average method was employed for the defuzzification procedure. The coefficient of determination ($R^2$), root mean squared error (RMSE), and mean absolute error (MAE) were used as the performance indicator metrics to evaluate the performance of analytical models. Full article

Post mortem incident investigations are vital to prevent the occurrence of similar events and improve system safety. The increasing interactions of technical, human and organizational elements in modern systems pose new challenges for safety management, demanding approaches capable of complementing techno-centric investigations with social-oriented analyses. Hence, traditional risk analysis methods rooted in event-chain reactions and looking for individual points of failure are increasingly inadequate to deal with system-wide investigations. They normally focus on an oversimplified analysis of how work was expected to be conducted, rather than exploring what exactly occurred among the involved agents. Therefore, a detailed analysis of incidents beyond the immediate failures extending towards socio-technical threats is necessary. This study adopts the system-theoretic accident model and process (STAMP) and its nested accident analysis technique, i.e., causal analysis based on systems theory (CAST), to propose a causal incident analysis in the railway industry. The study proposes a hierarchical safety control structure, along with system-level safety constraints, and detailed investigations of the system’s components with the purpose of identifying physical and organizational safety requirements and safety recommendations. The analysis is contextualized in the demonstrative use of a railway case. In particular, the analysis is instantiated for a 2011 incident in the United Kingdom (UK) railway system. Hence, the CAST technique requires information regarding incidents, facts and processes. Therefore, the case study under analysis provided the information to analyze the accidents based on system theory, in which the results of the analysis prove the benefits of a CAST application to highlight criticalities at both element- and system-level, spanning from component failure to organizational and maintenance planning, enhancing safety performance in normal work practices. Full article

Structural health monitoring is a crucial issue in areas with different hazard sources, such as Italy. Among non-invasive monitoring techniques, remote sensing provides useful information in supporting the management process and safety evaluations, reducing the impact of disturbances on the functionality of construction systems. The ground displacement time-series based on the analysis of Differential Interferometric Synthetic Aperture Radar (DInSAR) measurements, as well as the information about the geology of the area and the geometry of the construction under monitoring, provides useful data for the built environment’s structural assessment. This paper focuses on the structural monitoring and damage assessment of constructions based on the GIS integration of DInSAR measurements, geological investigation, historical surveys and 3D modeling. The methodology is applied to the residential area of Valco San Paolo in the city of Rome (Italy). Once the geological interpretation has confirmed the results of the DInSAR measurements, a quick damage assessment that considers all the possible conditions of the pre-existing damage at the time zero of the monitoring is shown for a damaged manufact in the area. The presented results highlight how the strategy to correlate the DInSAR-monitored ground settlements with the damage scales allows potentially to monitor continuous construction systems. Full article

Maintaining drinking water quality is considered important in building sustainable cities and societies. On the other hand, water insecurity is an obstacle to achieving sustainable development goals based on the issues of threatening human health and well-being and global peace. One of the dangers threatening water sources is cyanide contamination due to industrial wastewater leakage or sabotage. The present study investigates and provides potential strategies to remove cyanide contamination by chlorination. In this regard, the main novelty is to propose a sustainable decision support system for the dirking water system in a case study in Iran. First, three scenarios have been defined with low ([CN⁻] = 2.5 mg L⁻¹), medium ([CN⁻] = 5 mg L⁻¹), and high ([CN⁻] = 7.5 mg L⁻¹) levels of contamination. Then, the optimal chlorine dosage has been suggested as 2.9 mg L⁻¹, 4.7 mg L⁻¹, and 6.1 mg L⁻¹, respectively, for these three scenarios. In the next step, the residual cyanide was modelled with mathematical approaches, which revealed that the Gaussian distribution has the best performance accordingly. The main methodology was developing a hybrid approach based on the Gaussian model and the genetic algorithm. The outcomes of statistical evaluations illustrated that both injected chlorine and initial cyanide load have the greatest effects on residual cyanide ions. Finally, the proposed hybrid algorithm is characterized by the multilayer perceptron algorithm, which can forecast residual cyanide anion with a regression coefficient greater than 0.99 as a soft sensor. The output can demonstrate a strong positive relationship between residual cyanide- (RCN⁻) and injected chlorine. The main finding is that the proposed sustainable decision support system with our hybrid algorithm improves the resiliency levels of the considered drinking water system against cyanide treatments. Full article

This paper investigates the effects of seismic loads on tunnels in an attempt to provide better protection from earthquake shaking. Dynamic analysis of angular offset tunnels was performed, and the tunnels’ behavior under earthquake shaking and their response when using seismic isolation were analyzed in detail. The time history analysis was used to compute the stresses and deformation that develop in the tunnels during seismic events. Earthquake records with different frequency spectra were applied as seismic excitation to the twin tunnels. The excitation was applied normally to the tunnel axis, with peak ground accelerations of 0.10 g–0.30 g. The seismic event lasted 15 s, with a time step of 0.02 s utilized in the numerical analysis. Finite element modeling was employed to simulate the soil–tunnel interaction. Numerical models simulated twin tunnels passing through soft clay or stiff clay, with various earthquake records applied as seismic inputs. The effects of a silicon-based isolation material composed of silicon oil and fly-ash were compared with the use of traditional grout. The numerical model results show how seismic isolation affects the stresses and deformations that happen in tunnel bodies during earthquakes. Full article

In this article, the authors reviewed the existing system of weight control of heavy vehicles in the Russian Federation. In this research, the main shortcomings of the system, which prevent its effective functioning in relation to the use of road infrastructure, were determined. To solve these problems, we developed a model of the functionality of a telematic automated system of weight control of heavy vehicles, as well as defining the optimization tasks of the transportation process. Mathematical modeling of the operational factors that influence the system of weight control of heavy vehicles on roads was carried out. As a result of the research, the most significant parameters that have the greatest impact on the efficiency of the road were determined. By means of these parameters, it is feasible to choose suitable hardware and equipment for a weight control system. The methodology of developing automatic points for the weight control of heavy loads during road transportation was formulated. As a result of the study, it was concluded that the introduction of a telematic automated system of weight control of heavy vehicles would increase the efficiency of road transport on the highway by positively affecting its basic transport and performance indicators. Full article