bluuebunny/crossref_metadata_2025 huggingface dataset:
DATA‐INFORMED SAFETY ASSESSMENT OF EXISTING TRANSPORT INFRASTRUCTURES
Authors: Darò Paola , Longo Monica , Mancini Giuseppe , Negri Serena , Vliet Agnieszka Bigaj‐van , Allaix Diego Lorenzo
Published: September 2023

Bridges and tunnels are critical elements of the transport infrastructures network as they have often reached their design service life and are subject to unforeseen effects due to accidental actions, climate change or degradation processes. A thorough assessment process of the existing structures, aimed to support a preventive maintenance approach, is crucial at both European and national level. The assessment of existing concrete structures differs from the design of new assets, as the resisting models given are no longer valid with ongoing deterioration mechanisms. It is recommended to formulate the limit states considering the suspected damage mechanisms, with respect to adjusted target reliability levels in verifications. Existing assets also benefits from the availability of information related to the structural condition and the action effect on structures. As such, the EU Commission opened in 2019 the CSA call “Monitoring and safety of transport infrastructure”, granted to the IM‐SAFE project consortium and addressed in this paper, which specifically focuses on the proposal for further amendments to the existing EU standards on reliability assessment considering inspections, monitoring and testing and a new standard for preventive maintenance of transport infrastructure.
How to close the gap between applied strategies for infrastructure maintenance planning and the current state of research?
Authors: Köhler Jochen , Allaix Diego Lorenzo , Vliet Agnieszka Bigaj‐van
Published: September 2023

Bridges and tunnels are the critical parts of the transport infrastructure. The efficient maintenance of their structural performance during service life requires strategies for scheduling inspections and possible structural and/or organization interventions over time. Infrastructure owners have developed such strategies that are characterized by a corrective (failure based) and predetermined preventive (e.g. time‐based or use‐based) maintenance approach. It is broadly recognized that the currently applied strategies do not provide the basis for the optimal allocation of resources into maintenance of bridges and tunnels of the traffic infrastructure. The complexity of defining efficient and proactive maintenance strategies of structures is also well recognized by the academia, and promising solutions for maintenance decision‐making based on structural reliability methods and Bayesian Decision Theory have been developed and broadly discussed in the last decades. The suggested methods have, in principle, the potential to become the basis for efficient decision making in bridge and tunnel maintenance. However, they are not yet well implemented in a practical context.

In the current contribution we identify the gap between the technological developments in research and the corresponding applied knowledge in practice. Furthermore, we discuss how this gap might be closed. Special emphasis is directed to the corresponding role of standardization and education.
Multiple hazard assessment of bridges considering interdependencies
Authors: Stefanidou Sotiria , Markogiannaki Olga , Mikes Ioannis , Fragiadakis Michalis
Published: September 2023

Bridges are in direct interaction with the environment and thus are exposed to various natural hazards such as earthquakes and floods, that may result in severe damage and substantial direct and indirect losses. The multiple hazard events may be subsequent single events (e.g., a flood event followed by an earthquake) or combined multi‐hazard events (e.g., cascading ground failure event after an earthquake). The effect of multiple hazards on bridge fragility is related to the damage level of the bridge components and the associated failure mechanisms that may compromise the roadway network functionality. The scope of this work is to propose an approach for the multiple‐hazard assessment of bridges considering subsequent events and different damage scenarios of critical bridge components, i.e. piers, bearings and abutments. Therefore, the effect of the damage level of critical bridge components and their interdependence on the fragility assessment for subsequent hazard events is investigated. Different damage scenarios and hazard sequences are studied, providing insight into the damage mechanisms and the accumulation of damage. The approach is applied to the multiple hazard assessment of a case study typical riverine bridge in Greece and the results are comparatively discussed.
A common data environment for value‐driven data management in German road construction
Authors: Matthei Jonathan , Gölzhäuser Peter , Klemt‐Albert Katharina , Schulze Christian , Moharekpour Milad , Plattenteich Andreas
Published: September 2023

In recent years, the BIM method has been increasingly used in pilot projects for the planning and realization of road construction projects. Due to the strong political demand to expand the applications fields of BIM, there is also an increasing demand for a common data environment (CDE), as the central component of a successful and consistent BIM application [1]. In this context, uniform requirements, which currently exist only to a limited extent, are necessary to implement and successfully use a CDE in road construction. Based on a qualitative research approach questioning employees of state road administrations and a market analysis conducted through a qualitative study with CDE suppliers, a specification book for further CDE usage in road construction is being provided. In this context, functional and non‐functional requirements must be complied in order to implement and use a CDE in road construction successfully. Future research needs to take an in‐depth look at the operational phase and the challenges that arise when most state road administrations implement a CDE area‐wide.
Assessment of artificial intelligence‐ based techniques for the estimation of pile group scour depth
Authors: Jafari‐Asl Jafar , Seghier Mohamed El Amine Ben , Panagiotis Spyridis , Strauss Alfred
Published: September 2023

The scour phenomenon around piles is regarded as one of the main causes of serious damages to the pile‐supported structures such as bridges, jetties, wind turbines, and offshore platforms threatening their stability and sustainability in the long term. Thus, accurate forecast of scouring is vital for the design and operation of these structures. In this paper, three artificial intelligence‐based techniques including support vector regression, artificial neural network and random forest were applied to predict the local scour depth around pile groups. An experimental dataset is collected and used to construct the machine learning‐based models. The sediment number, shields parameter spacing, Keulegan‐Carpenter number and pile Reynolds number were used as input variables for the model development. Results assessment indicate that the artificial neural network model anticipated the highest performance among the three machine learning based models, with coefficient of determination of 0.97, and root mean square error of 0.15.
Vulnerability to traffic loads of typical Italian bridges in relation to the evolution of the code framework
Authors: Bozza Stefano , Fasan Marco , Noè Salvatore
Published: September 2023

Over the last century, the definition of the design traffic loads for Italian road bridges has undergone a continuous evolution, starting from the first code in 1933 up to the current code. The changes in the arrangement and in the intensity of the design loads that have occurred over the years resulted in significant variations, both decreasing and increasing the overall static demand required to the bridges compared to previous codes.

As part of a broader study on the structural risk of existing bridges with respect to traffic loads, it is certainly of interest to investigate the influence of the adopted design code on the risk itself. The paper presents some of the results of a study conducted with this purpose, regarding Prestressed Concrete beam‐and slab bridges with simply supported spans, one of the most common typology among bridges with medium‐small span.

The comparison between historical codes and current one is carried out in terms of internal forces of the most stressed girder, taking into account the transverse distribution of loads. The study can provide useful elements for the definition of a fast procedure for the preliminary assessment of typical existing Italian bridges based on the geometric characteristics of the decks and their design age.
Load‐Bearing Capacity of Support Block for Temporary Bridge Girder End with L‐Shaped Notch
Authors: Li Ruoxi , Chen Yu , Matsuda Isao , Azuma Hirotoshi , Yamaguchi Takashi
Published: September 2023

Recently, temporary bridges have been developed to facilitate rescue operations and minimize damage to affected areas. High‐strength bolts are preferred for end‐plate connections to expedite construction, reducing the bolt count. Regarding parts reusability, we propose an I‐girder designed with an L‐shaped notch and a novel support block as a structural member. Finite Element Method (FEM) analysis was conducted to investigate the girder end's buckling behavior and failure mode and to verify the effect of the support block's geometry and bolt arrangement on load‐bearing capacity. The findings indicate that the load‐bearing capacity of the girder end with the support block is equivalent to that of a standard I‐girder end, despite reducing the area of the support block's effective compression area by 40% under shear force and bending moment.
Incorporating measurement data to improve the fatigue assessment of steel bridges
Authors: Kwapisz Maciej , Pissermayr Sebastian , Lachinger Stefan
Published: September 2023

Fatigue calculations of steel bridges are particularly vulnerable to inaccuracies in stress assessment. Their accurate evaluation ensures structural safety and can contribute to extending the remaining service life of many structures. The following study deals with the incorporation of measured data into fatigue assessment based on FE calculations using the trains operating on site. The bridge under study was equipped with a large number of strain gauges to capture the global and local effects of train passages. In addition, some strain gauges were placed on both rails to determine train speeds and axle forces. A detailed finite element model of the bridge was created and the strains caused by selected detected trains were blindly compared with measured values. Although a fairly good agreement was obtained for most strain gauges without the need for model updating, some sensors did not comply with the measured values. In order to achieve better agreement, a model update was performed. The authors concluded with a comparison of the original and updated models and the determined operating trains with regard to the fatigue calculations and discussed the added value.
Prediction of corrosion rates in view of climate change with rising temperatures
Authors: Moro Fabrizio , Keβler Sylvia , Landi Filippo
Published: September 2023

Corrosion of steel in concrete is a complex process with many factors influencing its kinetics. Especially under on‐site condition, the prediction of corrosion rates is a challenge since many influencing factors such as the temperature change constantly. The whole corrosion process is the concert of three sub‐processes: (i) the anodic reaction rate, (ii) the cathodic reaction rate and (iii) the electrolytic conductivity of the concrete. Each of the processes show temperature dependency and existing corrosion monitoring systems record either data to evaluate part of the processes or the resulting corrosion rate. For service life estimates, prediction of corrosion rates is necessary. Consequently, the knowledge on the temperature effect on the corrosion rate is crucial, especially in view of rising temperatures due to climate change. This paper presents an overview on the existing knowledge on the temperature dependency on the corrosion rates; highlights the analysis of temperature data and provides guidance for service life prediction.
Multi‐risk assessment for bridges: the application of the Italian Guidelines
Authors: Sano Silvia Di , Costa Giancarlo , Giordano Pier Francesco , Pregnolato Maria , Limongelli Maria Pina
Published: September 2023

Bridges are essential elements in the built environment since they underpin the functioning of transportation systems. Nevertheless, they are vulnerable due to aggressive environment, demand beyond the design level, and other contingencies such as extreme events. The management of bridges represents a significant challenge for improving transport performance and ensure the safety of users. In Italy, bridge management is addressed by the recent “Guidelines for risk classification and management, safety evaluation and monitoring of existing bridges” which were issued by the Italian Ministry for Public Work in 2020. The guidelines propose an operational approach with distinctive characteristics: (i) risk‐based, i.e., based on the typical parameters of hazard, vulnerability, and exposure; (ii) multi‐level, i.e., they include six assessment levels (0‐5) of increasing complexity; and (iii) multi‐risk, i.e., they assess structural/foundation, seismic, hydrological and landslide risk. This paper presents a general overview of the 2020 Italian Guidelines and their application to a selected case study. Lessons from the application to the case study are drafted and possible criticalities highlighted.
Analytical Study on Yield Resistance for Staggered Arranged High Strength Bolted Frictional Joints
Authors: Qian Lin , Sakura Ryo , Yamaguchi Takashi , Hayashi Gen
Published: September 2023

The yield resistance of a high strength bolted frictional joint is evaluated based on the designed net cross‐section area. The Japanese Specifications for Highway Bridges specifies a designed net cross‐section area could be increased by a factor of 1.1 in the verification of the net cross‐section yield resistance at Serviceability Limit State in high strength bolted frictional joint where the bolts are placed in grid arrangement. In the design of a staggered arranged high strength bolted frictional joint, the width of strip to be deducted from the transverse section on account of a staggered arrangement w is used. And the width of strip w is negative when p2/(4g) is larger than d0. However, the designed net cross‐section area of a staggered arranged high strength bolted frictional joint is unclear. In this study, FE analysis of staggered arranged high strength bolted frictional joint was carried out by varying the number of bolts in the top column k and the gauge distance transverse to the loading g as parameters. The results indicated that in some cases, the ratio of the net cross‐section yield resistance predicted by FE analysis to the designed net cross‐section yield resistance may be less than 1.1, but a factor of 1.1 can be applied with a suitable arrangement.
Autonomous IoT for Condition Monitoring, Assessment and Predictive Maintenance ‐ Advances
Authors: Burtscher Stefan L. , Huber Peter , Binder Fritz , Bauer Hannes
Published: September 2023

Rocket NG is a startup with experts in civil engineering, electronics, and network engineering. We offer and operate a self‐developed end‐to‐end IoT system for condition monitoring, condition assessment and predictive maintenance. The system is reliable and ease to apply.

In this paper the autonomous monitoring system is discussed regarding security, reliability, ease of use and artificial intelligence on the edge (smart algorithms used on the nodes). Additionally, the importance of an easy installation and an intuitive data representation are on discussion.

Five applications will be presented. The first application is a crack monitoring on a cantilever bridge. There, different data acquisition modes will be shown for the assessment of static loads, dynamic loads and temperature induced displacements. The second application shows the crack width opening due to heavy transport. The third application addresses the wetting and drying of chloride contaminated water in a concrete wall beside a motorway. The fourth is a monitoring of a passive cathodic protection system. Finally, a digitalization of an analog legacy Extensometer is shown.
Machine Learning Applications in Nondestructive Testing of Concrete Structures
Authors: Algernon Daniel , Münch Ingo , Muller Aurélia , Thurnherr Claudia
Published: September 2023

Machine Learning bears great potential for data‐driven solutions in the field of nondestructive testing (NDT) of concrete structures. The analysis of the data collected with NDT methods, such as ultrasonics, impact‐echo and ground penetrating radar, can be complex and requires experience. The expected benefit of Machine Learning applications in this context goes beyond the increase of efficiency obtained by automating the analysis process. While traditional analysis approaches are usually solely based on key features according to the basic principles, Machine Learning algorithms can consider the full data content and reveal hidden correlations. For an organized approach to Machine Learning on NDT data, an analysis tool has been developed. The tool provides a graphical user interface to manage and label training/test data and interactively define the Deep Neural Network architecture. In particular, Convolutional Neural Networks, as proven successful in various image recognition tasks, are implemented. The Machine Learning concepts are demonstrated in show cases, comprising ultrasonic as well as impact‐echo applications. In particular, the relevance of a targeted preprocessing is addressed, comparing the effectiveness of time‐, frequency‐ and joint‐time‐frequency‐representations.
Data Cleansing & Overfitting Check for Interpretable ML in Concrete Design – a punching shear paradigm
Authors: Mellios Nikolaos , Spyrdis Panagiotis
Published: September 2023

Evaluation of shear capacity is crucial for existing concrete buildings and bridges. Shear failure can cause an abrupt and brittle loss of load‐carrying capacity, leading to load redistribution and progressive collapse. An internationally research and scietific discourse is actively ongoing on the best prediction model for shear, torsion, and punching shear capacity, with no clear consensus. A machine learning‐based strength model is suggested for accurate prediction of punching shear capacity, using Gaussian Process Regression and Support Vector Regression models. Data elaboration and thorough evaluation are needed to enhance the model's performance and interpretability. The paper discusses critical methodological steps based on the authors' experience of developing ML‐models for structural concrete design against punching shear failure using 544 full‐scale tests.
Multi source Interferometry Synthetic Aperture Radar for monitoring existing bridges: a case study
Authors: Calò Mirko , Ruggieri Sergio , Nettis Andrea , Uva Giuseppina
Published: September 2023

Bridge maintenance and safety are key goals for transportation management companies, considering that several vulnerability sources can affect these assets. Although necessary and hardly replaceable, traditional surveillance techniques represent time‐ and cost‐consuming activities that cannot be widely employed on the entire infrastructural portfolio. Hence, innovative techniques could be exploited, among which the use of Interferometric Synthetic Aperture Radar (InSAR). InSAR is a well‐known remote sensing technique that allows to reconstruct the displacement time‐series of persistent scatterers (PS) on the Earth's surface. The current available PS time series present different levels of spatial accuracy and temporal frequency, which depend on satellite data source. On this base, the paper deals with the evaluation of displacement scenarios for existing RC bridges, by means of two different popular satellite time‐series datasets: Sentinel‐1 and COSMO‐SkyMed. In detail, the analysis of the interferometric products provides different out‐comes, which are discussed in this paper. Pros and cons are provided with reference to a real‐life case study, showing differences in terms of geometry, resolution, and displacement results.
A deterministic model combining NDT to estimate permissible bending loads on trees
Authors: Muench Ingo , Loske Simon
Published: September 2023

The stability of trees is the subject of numerous studies, as their loss poses a threat to life and limb. Bending loads are responsible for the two most common failure modes: uprooting and stem break. Uprooting is strongly related to soil conditions, water saturation and the root system itself. These parameters are difficult to measure in situ. Since both failure modes result in loss of vitality, arguments from evolutionary theory suggest that roots and stems should have similar load limits under normal conditions. Therefore, we propose a deterministic model to estimate the allowable bending load in the stem of European beech (Fagus sylvatica). The model assumes a non‐linear stress distribution in the cross section. Destructive bending tests show that damage progresses in three stages. Furthermore, the local compressive and tensile strength in fibre direction are crucial parameters to determine the ultimate load. Since the tensile strength cannot be measured by NDT, the experimental data from the large‐scale tests are used to relate this parameter to the compressive strength from the NDT data. This provides a method for determining the risk of a tree, for example in urban areas. It is also useful for estimating the allowable limit of engineering loads on trees.
Strength reduction curves for corroded seven‐wire strands
Authors: Marra Matteo , Palermo Michele , Trombetti Tomaso , Silvestri Stefano
Published: September 2023

Steel seven‐wire strands are highly vulnerable to corrosion phenomena, which can strongly reduce their strength and ductility capacities. Following several parametric studies already conducted on corroded wires and strands, which allowed to identify the key parameters that govern their mechanical behavior, this paper presents a new resistance model for corroded seven‐wire strands. The model introduces a new coefficient that takes into account the variability of the corrosion in the seven wires that constitute the strand, with the purpose of representing the dispersion in the peak strength often emerged from tensile tests available in the literature. The lower bound of this coefficient is estimated analytically considering a brittle behavior for the wires. The ductile behavior is then taken into account by means of several Monte‐Carlo simulations of corroded strands. Finally, the resistance model allows to define strength reduction curves that allow to estimate the strength of corroded strands taking into account both the geometry of the corrosion and the steel material parameters. They represent simple engineering tools that are of great interest from both a design and safety assessment point of view.
The role of durability monitoring in taking infrastructure maintenance to the level of industry 4.0
Authors: Angst Ueli M. , Femenias Yurena Seguí , Moro Fabrizio
Published: September 2023

Over the last years, significant advances were made with respect to sensors, data logging, data communication, and algorithm‐based data analysis. These developments have the potential to take structural health monitoring, especially structural corrosion health monitoring, to the next level. This contribution focuses on corrosion and durability monitoring of reinforced concrete structures. It is discussed how monitoring can play an important role in the diagnosis of the condition of a structure, as well as in predicting the future evolution of material's ageing and related deterioration processes. Measuring chemical and physical parameters in the concrete can serve as “early warning system” to detect potential durability issues ahead of time and optimize repair. Combined with modelling tools and taking into account the exposure conditions, such information can form the basis for predictive maintenance. In addition, the roles of monitoring as a method for checking the effectiveness of repair products in‐situ and to assess the performance of new concretes with low greenhouse gas emissions are discussed.
Condition Information Models in the context of Structural Health Monitoring
Authors: Köhncke Martin , Keβler Sylvia
Published: September 2023

The realistic modelling of condition of structures with building information modelling (BIM) is beneficial for the assessment of structures. Condition survey in form of Structural Health Monitoring (SHM) and testing is one important source of data to support this task. However, the interpretation of data is even more reliable if the condition – or in the worst case – the damage of the particular structure is known. Therefore, the condition information should be easily available and preferably machine interpretable. Currently, standards for the integration and processing of condition/ damage information in BIM are missing. The integration of condition/ damage information in the BIM method is necessary for a more realistic representation of the structure. Going beyond the as‐build information towards the as‐is condition of the structure it requires information from Non‐Destructive‐Testing (NDT) and inspections in the BIM model. For that purpose, besides the information itself, it is crucial to define the interfaces between NDT and BIM for an automated transfer of data. The accuracy and reliability of the NDT methods is of importance to enable condition assessment. Consequently, this contribution provides a comprehensive approach for the integration of SHM and NDT data in BIM.
Optimisation of Cantilever Based Energy Harvester Design for Railway Bridges
Authors: Cámara‐Molina Javier C. , Romero Antonio , Galvín Pedro , Moliner Emma , Martínez‐Rodrigo María Dolores
Published: September 2023

In this paper, the authors investigate energy harvesting on railway bridges. A tuning process based on a statistical analysis of the mechanical energy generated by a lumped‐mass model is presented and validated. A cantilever‐based energy harvester configuration is applied, and the optimal design of 3D printed energy harvesters is studied. The electromechanical behaviour of the device is represented by an analytical model for the estimation of the energy harvested from train‐induced bridge vibrations. A genetic algorithm constrained to geometry and structural integrity is used to solve the optimisation problem. The design flexibility and energy performance are maximised by 3D printing of the substructure of the harvester. An optimal device prototype with PAHT CF15 substructure is designed and manufactured for a real bridge in the Madrid‐Sevilla High‐Speed line. The prototype is experimentally validated under laboratory conditions. Finally, the performance of energy harvesting is evaluated from in situ experimental data measured by the authors. The results allow quantifying the energy harvested in a time window of five hours and twenty‐seven train passages.
UAV‐based GPR prototype for structural monitoring of bridges: preliminary results and perspectives
Authors: Esposito Giuseppe , Salari Alan , Catapano Ilaria , Erricolo Danilo , Soldovieri Francesco
Published: September 2023

Structural Health Monitoring (SHM) is a challenging task requiring novel inspection paradigms and methodological tools devoted to support effective and timely maintenance actions. In this context, non‐destructive technologies (NDTs) turn out to be of paramount importance and Ground Penetrating Radar (GPR) is worthy of consideration for on‐demand, high‐resolution, subsurface surveys. Although GPR is an assessed technology, commercially available systems mainly work close to the structure under test, and those suitable to be mounted on moving platforms are hard to be used for the inspection of vertical structures. In this frame, mini–Unmanned Aerial Vehicles (UAVs) equipped with radar systems are worthy of consideration because of their potential advantages in terms of versatility. This paper deals with the design of a compact mini‐drone‐based radar prototype for contactless imaging of elongated, horizontal and vertical structures. Herein, the design guidelines are discussed qualitatively and the assembled prototype is presented. Moreover, a performance analysis is provided by accounting for simulated data and preliminary experiments carried out in controlled conditions. Conclusions analyze challenges and perspectives.
Predicting Wall Thickness Loss in Water Pipes Using Machine Learning Techniques
Authors: Taiwo Ridwan , Seghier Mohamed El Amine Ben , Zayed Tarek
Published: September 2023

Wall thickness loss in water pipes has been found to be positively correlated with water pipe failure. The reliability of water pipes reduces as their wall thickness loss increases. Although previous studies have investigated pipe failure modeling using historical failure data, however, indirect failure modeling via wall thickness loss is yet to be explored. Hence, this study develops machine learning (ML) models to predict wall thickness loss in water pipes. Random Forest (RF) and Gradient Boosting Machine (GBM) are chosen as the base models and are integrated with Bayesian Optimization (BO) algorithm for hyperparameters selection. The predictive models are evaluated using root mean square error (RMSE), mean absolute error (MEA), mean absolute percentage error (MAPE), and coefficient of determination (R2). Based on the evaluation metrics, the hybrid models (i.e., RF+ BO and GBM+BO) outperformed the base models (RF and GBM), showing the importance of the systematic selection of hyperparameters. The best model (RF + BO) achieved an RMSE, MAE, MAPE, and R2 value of 3.212, 2.494, 11.506, and 0.910, respectively. These metrics show the high predictive capability of the model, which can be used by water infrastructure management to predict wall thickness loss in water pipes.
Does vehicle‐bridge interaction resemble the effect of tuned‐mass dampers on bridges during earthquakes?
Authors: Homaei Hossein , Dimitrakopoulos Elias G.
Published: September 2023

In many seismic studies, the coupled vehicle‐bridge system is treated as a tuned‐mass damper (TMD)‐bridge system, and unsurprisingly, the vehicle usually reduces the seismic bridge response. The current study challenges this common belief. To this end, it investigates the influence of running vehicles on the seismic performance of bridges. Specifically, it compares the effect of vehicle‐bridge interaction (VBI) to that of a TMD on bridges subjected to earthquakes. The discussion explores the underlying physical mechanisms of VBI and TMD, and highlights the superficial similarities and the substantial differences between them. In this context, the study presents pertinent numerical simulations for a set of natural earthquake records.
Detection of wire breaks and corrosion in external prestressed tendons using a magnetic rope testing device
Authors: Vaurigaud Bastien , Germain Didier , Chemineau Hélène , Cherrier J.‐F. , Piednoir R. , Guyot Fabien
Published: September 2023

External prestressing tendons are a major structural element for the durability of concrete bridges. In France several cases of sudden breaks in external pre‐stressing tendon made of HDPE duct injected by cement grout directly in contact with strands have been recorded in the past decade [2].

In order to prevent this sudden breaks Cerema has experimented the magnetic rope testing technology from ropeways to develop a non‐destructive inspection technic of the free length and junction of prestressing. The method is based on magnetic leakage field detection and allows to detect defaults of the strands inside the tendon such as corrosion and wire breaks.

The article first focuses on the magnetic rope testing technic. Then tests previously performed on laboratory tendons with reference wire breaks will be analyzed for defaults characterization. Finally, the particular methodology adapted to the nondestructive magnetic inspection of prestressing tendons on site will be detailed. A general feedback including handling issues and analysis of non‐destructive magnetic controls completed with visual controls by removing the high‐density polyethylene (HDPE) sheath will be given.
Applications of State of the Art NDT Techniques in Bridge Inspections
Authors: Rapaport Guy
Published: September 2023

This article introduces the author's accumulated experience in applying state of the art NDT techniques in bridge special inspections. The NDT techniques and their applications introduced in this paper, including some examples from actual bridge inspections, are the Ultrasound Tomography, Impact‐Echo and Impulse‐Response. The main applications of those systems in bridge special inspections are in evaluation of post‐tensioned bridges' ducts' injection as the prestressing system is an internal system embedded inside the concrete structure, in integrity evaluation of road bridge decks surface structures (especially with asphalt pavement) and in detection of hidden faults and damages inside concrete structures. The main objective of a bridge special inspection is to evaluate the condition of a bridge by onsite testing, sample taking and laboratory examinations. Regular inspection techniques yield only limited results. Reliable data from the inspection is required for repair planning and for setting its logical timing and for ensuring the bridge safe usage. Suitable NDT techniques significantly assist in overcoming the downfalls of regular inspection techniques and in ensuring bridges' safe use, as the author has proven in large number of cases.
Unexpected flange crippling of a newly built cyclist bridge
Authors: Van Bogaert Philippe
Published: September 2023

Encouragement of cycling is an effective way to reduce energy consumption by traffic. Cycling lanes will, to the greatest extent practicable, be built close to currently used traffic roads in order to establish new, swift lanes that require little space. Building near railroads appears acceptable for the latter, preferably by cantilevered structures atop existing bridges. In the event that this is not acceptable, separate bicycle bridges may be constructed next to the railroad bridges. On the Brussels Ring Highway, close to the Zaventem Airport, the latter was the situation. The oblique bearing points at the extremities of the straight‐ended sections, used to construct this bicycle bridge experienced torsional moments during installation. This resulted in distinct folds in the bottom flange of the closed cross‐section of one of the six bridge decks. Both global FE‐models and more detailed models were created to explain this. None could adequately account for the observed flange crippling. The crippling can only be explained by an unintentionally increased torsion, which may have occurred during the manipulation of the bridge's component elements. Additional thin metal strips have been added to this section of the bicycle bridge to restore its bearing capacity.
Fire modelling and structural assessment of automated clad‐rack warehouses
Authors: Autiero Margherita , de Silva Donatella , Bilotta Antonio , Nigro Emidio
Published: September 2023

Automated Rack Supported Warehouses (ARSW) are self‐bearing rack structures designed to support, besides self‐weight and weight of products, environmental loads (i.e., wind, snow and seismic action) and all the other non‐structural elements. These structures are unique in the design; indeed, they represent a topic of great interest for both the scientific community and for the manufacturers of industrial racks. However, the behavior in case of fire of these structures is still poorly known. In order to study the fire resistance of these structures to consider a natural fire curve is necessary. In particular, a vertically traveling fire model in the upright frames, starting from a localized fire has to be modelled.

This paper proposes a fire model that considered both the vertical and horizontal fire propagation, evaluated and validated against experimental test results. In addition, advanced thermo‐mechanical analyses using both natural and nominal fire curves, were performed with a finite element software (SAFIR), which allows modeling Class 4 steel elements considering the local instabilities that can occur in these slender sections. A comparison between the capacity models that the regulations propose for these structural elements, was also conducted.
Bond between Ultra High‐Performance Fiber Reinforced Concrete and existing concrete: a review
Authors: Berthod Lara , Trento Daniel , Faleschini Flora
Published: September 2023

The application of Ultra High‐Performance Fiber Reinforced Concrete (UHPFRC) is increasing worldwide to repair and strengthen existing structures. One of the main applications is in bridge components, e.g., to repair bridge decks and piers, but also to strengthen existing floors in residential or industrial buildings and to realize construction joints in prefabricated members. To properly design a strengthening intervention with UHPFRC, bond between the existing structure and the new layer of reinforcing material should be properly developed. In this work, a review about the interface behavior between UHPFRC and concrete is carried out, analyzing in detail the available test methods, and the variables influencing the bond behavior between the two materials. Among them, the role of moisture exchanges, the material properties of the concrete, the surface roughness, and the effect of bonding agents are discussed in detail. This work shows only proper surface treatments can enhance bond strength, otherwise they could be detrimental. In most previous experiences, UHPFRC bond efficiently with the substrate, resulting in composites that behaves monolithically.
Spanish guides and code specifications on concrete bridges inspection and maintenance: an overview
Authors: Martí‐Vargas José R. , Castro‐Bugallo Carmen , Navarro‐Gregori Juan , Mateu‐Sánchez Juan A.
Published: September 2023

The maintenance needs of bridges have often resulted in costly interventions, not only due to the lack of an adequate inspection and maintenance plan, but also due to a common practice in the design‐building process focused on solving requirements under “instantaneous” economic conditions. This situation is not compatible with the new paradigm of environmental, social and economic sustainability. Aspects related to durability, service life, life cycle, circular economy, etc. are increasingly present in codes and practice guides, so the inspection and maintenance take special relevance by considering economic factors of “deferred” scope. To contextualise the Spanish case, this paper presents a practical overview of the main documentary references that, in the form of regulations and guides, establish mandatory specifications and/or provide tools to facilitate the inspection and maintenance of concrete bridges. From a historical perspective, the changes introduced by the evolutions of main rules are highlighted, starting from the double conception of reinforced concrete and prestressed concrete, passing through the integration towards structural concrete, and reaching our days with the recent appearance of the Structural Code contextualized in the framework of the Eurocodes.
Hybrid protective coatings for construction steel bars
Authors: Matziaris Katia , Tsampali Evangelia , Tsardaka Eirini‐Chrysanthi , Stefanidou Maria
Published: September 2023

A hybrid‐based coating is proposed for its performance against accelerated corrosion of steel bars used for concrete reinforcement. The innovative, hybrid nano‐modified character of the coating is applied during steel's welding process (at around 400°C) ensuring durability and adhesion to the steel bars while energy saving is a necessary feature. With the intention of comparing product sustainability, both water‐based and organic solvent based polymeric matrix was used. Formulations were designed according to the final desired performance of the coating's behaviour and anti‐corrosion properties. For all the above complex formulations, an ultrasonic mixing method was applied, and all coatings have been sprayed. Final performance of coated steel was tested after exposing samples in salt mist, using sodium chloride solution (3.0% w/w) for 7 days. Detailed imaging modalities for metallic surfaces have been performed after testing samples under Scanning Electron Microscopy (SEM).
Model updating of plate composite structure using particle swarm optimization algorithm
Authors: Quang Minh Tran , Bento Ana Margarida , Tiago Ferradosa , Sousa Hélder S. , Duc Binh Nguyen , Cam Nhung Nguyen Thi , Campos e Matos José
Published: September 2023

The Finite Element Method (FEM) is a widely applied method for design calculations in many industries, including civil engineering, textile technology and aerospace. Computational simulation is subject to many uncertain parameters that greatly affect the results of structural analysis and evaluation. This is especially true for structures made of composite materials and complex structures. Determining the exact computational parameters is difficult because the structure involves many materials and components. Not to mention that for some structures, removing some additional components also affects the calculation results. Therefore, the present research aims to propose a simple and straightforward calculation method that ensures the accuracy of the finite element model based on swarm intelligence, namely the Particle Swarm Optimization (PSO) algorithm. The results reveal a good compromise between the laboratory results and the computational simulations for the model scale studied. In this way, an accurate and reliable model can be produced that can be applied to structural health monitoring, design optimization, or reliability analysis.
QUICK‐B‐WIM: Large scale application of a moving force identification method on a railway bridge
Authors: Riedel Henrik , Firus Andrei , Vospernig Michael , Apostolidi Eftychia , Schneider Jens
Published: September 2023

Globally, infrastructure faces the challenge of aging bridges and increasing traffic loads. Extended operational availability and safety of the bridge structures can be enabled by Structural Health Monitoring (SHM) methods. For this, knowledge of the actual vehicle loads is of crucial importance for evaluation of the remaining service life. Direct measurement of the moving loads, however, is either very cumbersome and requires considerable financial effort or in some cases even impossible. Bridge Weigh‐In‐Motion (B‐WIM) methods use the structural responses of bridge structures to determine the external vehicle loads. The present contribution deals with the testing of a novel moving force identification (MFI) method, denoted as Quick‐BWIM (QBWIM) under real operating conditions. In this study, 43 train crossings within 18 hours were investigated and compared with a nearby axle load measurement point. QBWIM achieves an average error of only 1.1% with a standard deviation of 7.5% for individual axles and an average error of 2.1% with a standard deviation of 1.5% for the identification of gross vehicle weights (GVW). This study shows that QBWIM can meet European and US guidelines even under poor conditions and is able to reliably determine axle loads in real time.
Effect of material strength uncertainties on the structural assessment of existing RC bridges
Authors: Zizi Mattia , Di Gennaro Luciana , Bencivenga Pasquale , De Matteis Gianfranco
Published: September 2023

The structural assessment of existing bridges is a topic of noteworthy interest for the engineering community given the general conservation state characterizing the infrastructural assets and the need of performing upgrading interventions. One of the key aspects of this process is represented by the material strength definition based on destructive and non‐destructive tests. As for reinforced concrete structures, the design strength determination of both reinforcing steel and concrete should account for the statistical distributions of strength values returned by tensile and compressive tests, respectively, as well as the related confidence factors assumed for the analysis. In this context, existing reinforced concrete structures commonly exhibit a notable dispersion of resistance values making necessary the adoption of improved approaches for design strength determination. The present paper addresses this topic by analyzing the effects of uncertainties on the capacity assessment of reinforced concrete elements which are typical of Italian bridges realized during the last century. The study aims at highlighting how the knowledge process based on investigation campaigns can influence the capacity assessment of existing structures.
Risk assessment of a masonry arch bridge: from on‐site inspections to continuous monitoring
Authors: Borlenghi Paolo , Gentile Carmelo , D'angelo Manuel , Ballio Francesco
Published: September 2023

The paper presents an application of a risk‐based methodology – developed as a joint research between Politecnico di Milano and Regione Lombardia – for the prioritization of interventions and the subsequent monitoring of a masonry arch bridge affected by riverbed erosion. Firstly, available data on the regional bridge inventory is evaluated to assign a structural and hydraulic class of attention. Subsequently, onsite inspections and in‐depth documentary analysis were performed, and, finally, a quasi‐static structural and hydraulic monitoring system was installed to detect scour‐induced effects. The monitoring of piers rotation is performed using tiltmeters installed at the skewback of the arches. Environmental parameters, such as temperature, water level and riverbed changes, are also measured to check possible correlation with the monitored rotations. The results from the first two years of monitoring highlight abnormal changes in the rotationtemperature correlation of some piers.
A case study for the reliability evaluation of an existing prestressed bridge according to current Standard
Authors: Poeta Alberto , Micozzi Fabio , Gioiella Laura , Dall'Asta Andrea
Published: September 2023

The structural reliability of existing post‐tensioned concrete bridges is a non‐trivial topic because of uncertainties affecting many parameters involved in their assessment process. This last is performed according to the current Codes specification through the partial factor method. Such method can be applied considering realistic material properties variability and accounting also for ageing, deterioration, and damage by means of all prior data that can be collected, as stated in present Standards like Fib 80. These data span from existing design specifications up to original design documents and experimental campaigns for the material investigations through in‐situ tests. Regarding existing post‐tensioned concrete bridges, the prestressing cables characteristics are the most important components in the reliability of the final safety verification, but their values (in terms of probability distribution) are affected by many uncertainty sources. This paper focuses on the evaluation of the structural reliability of a real case study by applying the partial factor method and by comparing the results achieved considering the ideal case of perfect knowledge with those achieved considering different levels of knowledge acquired through simulated experimental tests.