bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of bridge Post‐Tensioning systems using non‐destructive (ND) inspection methods
Authors: Quaglini Virginio , Pettorruso Carlo , Cattaneo Sara , Rossi Dalila
Published: September 2023

Reinforced concrete bridges with post‐tensioned cables are particularly critical structures, as the degradation of the tendons is not fully detectable through conventional investigation methods and/or through visual inspections, due to the intrinsic nature of the structural typology. After shortly reviewing the main applications of current non‐destructive (ND) methods available for investigating the deterioration of tendons and grout, the paper presents a simple procedure to rank these methods through a series of metrics formulated to evaluate the various technologies under four different aspects: accuracy of measurement, ease of use, cost, impact on the operation of the bridge. The procedure has the aim of providing bridge owners with a decision tool which can assist in the selection of the optimal ND technology available to detect a particular strand or grout defect.
Remedial measures works programme for Slovenian motorway infrastructure
Authors: Kušar Matej , Jurgele Mitja
Published: September 2023

The motorway infrastructure consists of pavements, bridges, tunnels, noise barriers, drainage systems, electro‐mechanical equipment and road furniture. All of them need to be at the adequate performance levels to ensure appropriate availability, comfort and safety. To fulfill this condition, road authorities must regularly carry out maintenance, rehabilitation and reconstruction works. As engineering structures have various service lives, performing remedial works for each individual structure at the optimal time would result in frequent road closures on the same road sections, significantly reducing the road availability for the users. Consequently, a works programme of remedial measures is needed which combines the measures on the same road section to the same time frame. The times planned for performing remedial measures therefore cannot be optimal for every structure in the road network, however they can be optimal from the road's availability and total costs perspective. An appropriate coordination between individual types of infrastructure, selection of measures and a method of merging these measures to the individual road sections must be performed. The paper discusses the integration of the results of individual management systems into a unified works programme.
Monitoring on federal highways bridges: current situation, future opportunities & digital implementation
Authors: Hindersmann Iris , Bednorz Jennifer , Nieborowski Sonja
Published: September 2023

Monitoring on road bridges in Germany is rare and mostly designed to deal with existing damages and deficits, as a survey of the Federal Ministry of Digital and Transport in Germany has shown in 2020. Other use cases are monitoring to support structural inspection, monitoring to monitor significant structures, or impact monitoring. The objectives, benefits and examples of the various use cases are described in the present article. Monitoring results are most useful when they are combined with other information about the structure, such as repair measures or damage development, in a common data environment. The Digital Twin is a possibility to merge the existing information und represents the highest expression of digital implementation. The Digital Shadow with an automatic data link from the physical to the digital object and the manual data link from the digital to the physical object represents a preliminary stage of the Digital Twin. The implementation of a Digital Shadow is already taking place at a demonstrator structure of the BASt. The basis for the Digital Shadow is the parametric BIM model. In a selected BIM application, the available information was compiled for this bridge and visualized in a common data environment.
Long‐term Resistivity Monitoring of a Lock – Valuable Data for different Durability Issues
Authors: Spörel Frank
Published: September 2023

A better knowledge on the exposure conditions of structures can help to evaluate the transferability of lab tests results to practical application or to generate a basis for modeling of different durability aspects. About 20 years and 10 years ago, a monitoring system was installed in two locks to get information on the temperature exposure and the degree of saturation of the concrete cover zone by means of continuous resistivity measurements with the Multi‐Ring‐Electrodes (MRE) and Multitemperature Probes (MTP) at different distances to the concrete surface. Due to the fact that resistivity is influenced by many more parameters than just the degree of saturation it is very complex to determine the degree of saturation. Uncertainties remain as concrete properties develop over the years and the cover zone which is of mayor interest for durability is additionally affected by casting and curing and later on by the exposure conditions. A deficiency of the Arrhenius equation to compensate for temperature effects on resistivity under certain conditions finally helps to overcome that difficulty. A data evaluation concerning freeze‐thaw attack gives examples and indicates possible further applications like carbonation.
Automatic Multi‐label Classification of Bridge Components and Defects Based on Inspection Photographs
Authors: Pâques Matthieu , Law‐Hine Didier , Hamedane Otmane Alami , Magnaval Gauthier , Allezard Nicolas
Published: September 2023

When performing visual inspections of bridges, experts collect photographs of defects to assess the overall condition of the structure and schedule maintenance plans. Such inspections are labor‐intensive, and computer vision‐based systems are being investigated as automated tools to assist the experts in their inspections. An important aspect however remains to ensure the representativeness of the data accounting for the sheer size, complexity and variety of the bridge components and defects being reported. Here, we perform a multi‐label classification on a dataset (SOFIA dataset) that consists of 139,455 images of types of bridge components and defects among which 53,805 are labeled (13 classes for each type). The dataset containing class imbalance and noisy labeling is processed using visual embedding computed from unsupervised deep learning methods. A combination of class‐balancing techniques is investigated on the state‐of‐the‐art Vision Transformer model. Interclass relations, which determine whether a class of defect should be part of a class of bridge component, are implemented with an additional filtering step. The whole method is also deployed on the CODEBRIM benchmark dataset resulting in an improved accuracy score.
Text Recognition for 2D Bridge Plans Using OCR‐Algorithms
Authors: Peng Mengyan , Kang Chongjie , Marx Steffen
Published: September 2023

The 2D bridge plans play an essential role in renovations or new replacements of transport infrastructures. As an indispensable component of plans, text serves as dimension labels, descriptions of materials, etc. Optical Character Recognition (OCR) can convert text in image into machine‐encoded format, and has high potential and invaluable practical worth for analyzing, managing, and extracting textual information from plans. First, the selection of OCR‐algorithms and the sampling of textual fragments from 2D bridge plans, including historic plans with handwritten text and digital plans with printed text, was carried out. Subsequently, the performances of different open‐source OCR‐algorithms on different textual fragments from 2D bridge plans are compared. In this process, the accuracy at character level and word level are chosen as two main factors to evaluate their performances. Finally, the most potential OCR‐algorithms for the text recognition on 2D bridge plans are proposed.
Optical sensors for the durability assessment of cement‐based infrastructure
Authors: Grengg Cyrill , Müller Bernhard , Zögl Iris , Sakopanig Marlene , Mittermayr Florian , Mayr Torsten , Sterz Karl Leonhard , Juhart Joachim , Galan Isabel
Published: September 2023

The corrosion‐related damages on concrete infrastructure account globally for several billion US dollars annually. Up to 38 % of these costs could be saved by the application of optimized materials and/or more efficient monitoring technologies. In this contribution a novel sensor technology is presented, based on luminescent pH sensitive dyes, to quantitatively determine the pH distribution in cement‐based construction materials. Different sensor platforms were explored resulting in high‐resolution imaging techniques, as well as in miniaturized sensor probes for field application and in situ monitoring. To this point, pH sensors were successfully applied for cementitious materials to (i) quantitatively characterize the carbonation state in the lab, (ii) gain further understanding on phase assemblages and internal pH evolution related to carbonation, (iii) reveal that the actual pH at the inflection point of phenolphthalein may strongly vary depending on physicochemical material properties, (iv) monitor the pH evolution during the early hydration of different cementitious materials, and (v) measure carbonation depths using miniaturized sensor probes adopted for field applications.
Laminated glass slabs design challenges: dynamic identification of a fractured pedestrian walkway
Authors: Rosso Marco Martino , Aloisio Angelo , Bedon Chiara , Marano Giuseppe Carlo
Published: September 2023

Design codes provide requirements for traditional slabs to ensure both safety levels and in‐service functionality criteria. However, for existing structures, an initial diagnostic knowledge phase is essential to characterize the actual health state, e.g. based on structural health monitoring (SHM) with operational modal analysis (OMA) techniques. Considering recent advancements in glass as a structural material, laminated glass (LG) slabs are increasingly used in constructions and are mostly designed to account for the intrinsic brittleness and limited tensile resistance of glass. The latest pre‐code CEN/TS 19100:2021 is paving the road for an imminent future Eurocode 10 dedicated to providing new standards for the innovative use of structural glass. In the current study, a brief review of the design challenges of working with structural glass is presented. After that, the authors provided a simple experimental dynamic identification example of an LG pedestrian walkway located in the Basilica of Aquileia, Trieste (Italy). Specifically, the fundamental mode was compared to a healthy and a partially fractured LG slab. Functionality aspects related to comfort standards with respect to in‐service vibration issues are also detailed.
Economic assessment of corrosion prevention measures in new structures
Authors: Hernandez Juan Daniel Cassiani , Valcarcel Juan Mauricio Lozano , Kränkel Thomas , Gehlen Christoph , Keβler Sylvia
Published: September 2023

Chloride‐induced corrosion is a main cause of deterioration in reinforced concrete (RC). The premature deterioration of RC leads to unplanned repairs, hence elevating the direct and indirect costs of the RC infrastructure. The current prescriptive durability design approach has proven to be insufficient in assuring the durability of the RC exposed to chlorides. The objective of this study is an economical evaluation of several prevention measures for chloride‐induced corrosion following the performance‐based approach. A case study is inspired by a real set of RC columns, which suffered from chloride‐induced corrosion damage after 14 years in service. The considered prevention measures are the use of different binder systems, variation of the water/binder ratio, and changes in the concrete cover. To compare the obtained results, a reference design is set with a concrete mix and a cover thickness according to the requirements of the prescriptive approach described in the European standards. The results show that a balance between the binder type, concrete cover and water/binder ratio is necessary in order to optimize the costs while assuring the durability of the RC element.
External Confinement with Basalt Fiber Ropes in Existing Reinforced Concrete Structures
Authors: Rousakis Theodoros , Macha Makrini
Published: September 2023

Existing reinforced concrete structures designed according to previous generation seismic codes, often suffer from premature, abrupt and detrimental failures in cases of intense earthquakes. In this study the seismic response of an existing building is analytically investigated while taking into account the influence of different detailing of brick wall infills. The assessment is performed with 3D static inelastic (Pushover) or with incremental Dynamic time‐history analyses (IDA) with the SeismoStruct Software. Buildings with inadequate performance receive continuous transverse pre‐tensioned Basalt Fiber Ropes (BFR) as external shear and confining strengthening reinforcement. The inelastic analyses conclude that buildings with short columns suffer from early collapses at low top displacements due to detrimental local shear failure of the above‐mentioned members. Both shear and crush confined concrete related failures of the critical columns are eliminated and overall base shear strength is increased. BFR external wrapping increases the ultimate top building displacements as well. IDA are thoroughly elaborated to assess the collapse mechanism of the structures and conclude ultimate base shear and top displacement values for the critical cases of buildings under investigation.
Performance Prediction of Anchors in SFRC using Minimally Invasive and Non‐Destructive Techniques
Authors: Mellios Nikolaos , Kruschwitz Sabine , Spyrdis Panagiotis
Published: September 2023

Fastenings are crucial for the upgrade of existing structures, by either enhancing structural components or modernising and expanding structures and structural systems. Whilst concrete is prevailing in the existing building stock, new types of concrete composites are increasingly used to improve the sustainability and overall structural performance of built assets. The addition of short dispersed fibres is a material technology with several applications. This paper addresses the synergy of fastening elements, introducing localised loads in concrete substrates, and of fibres, particularly in terms of the fibre orientation and density in the load application area, which is a significant quality aspect. The possibility to forecast this synergy based on non‐destructive or minimally invasive testing methods is an efficient tool to increase confidence in the design load‐bearing performance of the anchorages. Initially, previous literature and own investigations on such techniques are presented. Furthermore, a methodology is presented on associating such information to predict a single anchor's resistance on the basis of sophisticated non‐linear analyses and testing with engineered fibres alignments.
Strain‐based autoregressive modelling for system identification of railway bridges
Authors: Anastasia Stefano , Marcías Enrique García , Ubertini Filippo , Gattulli Vincenzo , Martìnez Pedro Poveda , Gorriz Benjamín Torres , Chorro Salvador Ivorra
Published: September 2023

Vehicular traffic represents the most influential loads on the structural integrity of railway bridges, therefore the design on dynamic criteria. This work explores the use of strain dynamic measurements to characterize the health condition of railway bridges under moving train loads. Specifically, the approach proposed in this work exploits the implementation of auto‐regressive (AR) time series analysis for continuous damage detection. In this light, continuously extracted AR coefficients are used as damage‐sensitive features. To automate the definition of the order of the AR model, the methodology implements a model selection approach based on the Bayesian information criterion (BIC), Akaike Information Criterion (AIC) and Mean Squared Error (MSE). In this exploratory investigation, the suitability and effectiveness of strain measurements against acceleration‐based systems are appraised through a case study of a simply supported Euler‐Bernoulli beam under moving loads. The moving loads problem in terms of vertical accelerations and normal strains is solved through modal decomposition in closed form. The presented numerical results and discussion evidence the effectiveness of the proposed approach, laying the basis for its implementation to real‐world instrumented bridges.
Nonlinear analysis procedures for safety assessment of existing RC bridges under traffic loads
Authors: De Matteis Gianfranco , Carbonari Sandro , Chisari Corrado , D'Amato Michele , Mattei Francesca , Zizi Mattia , Braga Franco , Caprili Silvia , Dall'Asta Andrea , Gara Fabrizio , Salvatore Walter
Published: September 2023

The Italian infrastructural asset, mainly consisting of RC bridges, is affected by significant obsolescence: many bridges overpassed their theoretical nominal life and did not experience any maintenance intervention. Such a critical scenario is even worse if it is additionally considered the increase of vehicular traffic that occurred in the last decades. From a management point of view, many structures needed restrictions on use due to their inadequacy to withstand the traffic load provided by the current codes. This is a direct consequence of accurate safety assessments of such structures. In this paper, the opportunity to adopt nonlinear analyses for the safety assessment of existing RC bridges is discussed. The safety‐format proposed in EuroCode 2 for designing new RC bridges and based on nonlinear analysis methodology is critically reviewed to consider its possible application to existing bridges. Then, the estimation of modelling uncertainty is proposed to define some acceptance criteria for the specific numerical solution strategy to be used, following the most recent international research outputs. Finally, a case study is addressed with the aim to compare linear and nonlinear results, the latter based on a calibration and verification of the adopted modelling strategy.
Operational modal analysis for supporting the retrofit design of bridges
Authors: Nicoletti Vanni , Martini Riccardo , Amico Lorenzo , Carbonari Sandro , Gara Fabrizio
Published: September 2023

Ambient vibration tests and operational modal analysis are commonly adopted worldwide to identify the dynamic behaviour of structures because they offer several advantages such as the use of portable light equipment, the possibility to be performed without interruptions of the structure serviceability, and the use of ambient noise to globally excite the construction. Ambient vibration tests are also usually adopted in structural health monitoring systems to control changes in the dynamic behaviour of structures over the time. In this paper the dynamic identification of two multi‐span simply supported prestressed RC deck bridges in Central Italy is presented. The modal parameters of the structures are identified adopting operational modal analyses based on in‐situ ambient vibration measurements. The experimentally identified dynamics is adopted to assess the bridges' seismic retrofitting works and to investigate their dynamic behaviour in the retrofitted state.
Long‐term validation of virtual sensing of a railway bridge with ballasted superstructure
Authors: Lorenzen Steven Robert , Berthold Hagen , Fritzsche Max Johannes Alois , Rupp Maximilian Michael , Riedel Henrik , Apostolidi Eftychia , Schneider Jens
Published: September 2023

Railway bridges have a long lifespan, which is challenged by the constant development of vehicles leading to increased loads that they were not originally designed for. To ensure the longest possible use of existing structures, a sensor‐based structural health monitoring system can make a significant contribution. However, due to economic reasons and the inaccessibility of many points of interest, sensors cannot be installed everywhere. Therefore, in most cases, only a few sensors are available at a few points of interest, and methods that aim to reconstruct structural responses at unmeasured points from these measurements are referred to as virtual sensing. In this paper, we have analyzed 19,075 passages recorded on a steel trough bridge with a ballast superstructure and a span of 16.4 m, together with weather data. Our findings show that the influence of train type and speed has a significantly higher impact on the results than environmental factors. The investigation revealed that the model‐based analysis produced similar results to the data‐driven analysis concerning acceleration signals. However, when analyzing strain signals, the two approaches yielded distinctly different results.
A proposal for low cost condition assessment method for existing RC bridges
Authors: Stochino Flavio , Mistretta Fausto , Sassu Mauro , Zucca Marco , Puppio Mario Lucio
Published: September 2023

Aging infrastructures require huge budgets to preserve their functionality and the lack of effective maintenance leads to increasing deterioration and therefore higher repair costs. For these reasons, assessing the condition of infrastructures becomes mandatory, with particular attention to the ones still in service even when their life limit has been exceeded. In particular, this problem is really important in Countries, like Italy, in which there are several operating bridges at the end of their service life. In this framework, many companies responsible for the management of road networks have turned their interest towards Bridge Management Systems (BMS). This paper presents a fast and low‐cost method for condition rating of reinforced concrete bridges. The proposal is based on visual inspection and non‐destructive testing. A specific parameter is designed to take into account the mechanical degradation of materials and the damage location at the structural sub‐component level. Some benchmark case studies have been discussed in order to compare the proposed method with other approaches available in literature.
A framework for management of transportation infrastructure based on key performance indicators
Authors: Tanasić Nikola , Blumenfeld Tim , Hajdin Rade , Schiffmann Frank
Published: September 2023

To facilitate decision‐making on optimal maintenance strategies for ageing traffic networks, a novel quantitative framework is presented. The framework comprises evaluation of the four KPI: reliability, safety for users and third parties, availability, and sustainability. The evolution of KPIs over time is subject to damaging processes and maintenance interventions. To characterize the impact of damaging processes and maintenance interventions, relevant performance indicators (PI) are selected that are used to estimate the key performance indicators (KPI). The native units of each KPI are normalized to a scale from 1‐5. Normalized KPI values are plotted on spider diagram for each time instance, rendering a 3D body with the volume which represents the network's quality over time, for considered maintenance strategies. The framework is aimed for medium to long‐term maintenance planning and can be further upgraded to account for risk & resilience analyses. The framework is implemented in a web‐based prototype to demonstrate its utilization in practice and future management systems.
On the use of domain adaptation techniques for bridge damage detection in a changing environment
Authors: Giglioni Valentina , Poole Jack , Venanzi Ilaria , Ubertini Filippo , Worden Keith
Published: September 2023

Structural Health Monitoring of civil infrastructures often suffers from the limited availability of damage labelled data. The work here seeks to overcome this issue by using Transfer Learning approaches, in the form of Domain Adaptation, for leveraging information from a source structure with determined health‐state labels to make inferences on an unlabeled monitored structure. The idea is to exploit source data to train a Machine Learning algorithm and achieve improved early‐stage damage detection capabilities across a population of bridges. To account for differences in the underlying distributions of each structure, Transfer Learning is seen as a strategy enabling population‐level bridge SHM. In this paper, the natural frequencies obtained from multiple vibration measurements are extracted to characterise different domains during pristine and abnormal conditions. Such damage‐sensitive features are aligned via Domain Adaptation and used to train a standard classifier within a shared feature space. The methodology is validated on the heterogeneous population composed of the Z24 and S101 bridges. The results prove the effectiveness to successfully exchange damage labels, thus increasing available information for health‐state inference for SHM applications with sparce datasets.
Barriers and opportunities towards monitoring and asset management of EU transport infrastructure
Authors: Scibilia Elena , Hoff Inge , De Urquia Miguel A. , Vliet Agnieszka Bigaj‐van
Published: September 2023

Recent technological developments have clear potential to support paradigm shift from corrective maintenance towards risk‐based/predictive maintenance through data‐informed decision‐making. The most promising developments are already taken up by local communities. Acknowledging that successful development, rollout and implementation of standardisation is only possible with thorough understanding of the full context, the H2020 CSA IM‐SAFE project evaluated the main barriers and opportunities that need to be overcome to enable well‐functioning monitoring and maintenance of transport infrastructure. As the European countries have different political, economic and social situations, the analyses have been performed on the national level, and the outcomes have been aggregated to identify main barriers at EU level. This paper presents the outcomes of the analysis of PEST barriers and SWOT analyses and discusses the connection between the barriers and the limitations in the existing EU monitoring standards and opportunities for the national implementation. Finally, the article highlights the importance to consider different scenarios and their potential environmental constraints in order to ensure that the exploitation opportunities are successful and sustainable in the long‐term.
MT‐InSAR monitoring for tunnel induced settlements in urban area
Authors: Della Ragione Gianluigi , Rocca Alfredo , Perissin Daniele , Bilotta Emilio
Published: September 2023

Satellite Interferometric Synthetic Aperture Radar (InSAR) is an accredited technology used in many fields in the last decades, but represents a relatively new technology for civil infrastructures monitoring. It allows to measure displacement along the line of sight (LOS) of the sensor with a millimetric precision. This study was conducted to show the potential of SAR sensors, mounted on satellite platforms, in detecting displacements induced by the excavations of tunnels in urban areas. Advances in remote sensing, such as the development of Multi‐Temporal InSAR algorithms, have overcome the limit of InSAR due to spatial‐temporal decorrelation of the phase measurement, thus improving the precision of the outcomes. Here the COSMO‐SkyMed satellite constellation acquired data over a small area in the city of Naples, affected by the excavation of twin tunnels. Data were processed with the SARPROZ software, while tunnel induced settlement were predicted with empirical methods. To allow comparison, displacements along LOS were projected in the vertical plane. Results indicate a good agreement between the monitored data and the predicted profile of settlement, further confirming the potential of MT‐InSAR in detecting displacements induced by tunneling excavation in urbanized area.
Automated Creation of an IFC‐4 Compliant Damage Model from a Digital Inspection Supported by AI.
Authors: Furtner Peter , O'Brien Peter
Published: September 2023

This paper describes a technological solution for digital condition inspection, which includes the entire process, starting with on‐site image acquisition upto the IFC‐4‐compliant result. In detail, the process includes the following steps:

– Digital image recording of the entire object on site

– Automated creation of a 3D model from the image data in the form of a textured scatter plot

– Generation of a BIM geometry model from the scatter plot

– Fully automated damage detection in the original images using AI (accurate to the pixel)

– Correct location of the damage on the 3D model as a polyline and linking the damage with the associated damage information in a database (e.g., crack length, crack width, damage area)

– Fully automated creation of an IFC‐4 compliant damage model.
Probabilistic Analysis of Corrosion Rates and Degradation of Weathering Steel Bridges
Authors: Sykora Miroslav , Kreislova Katerina , Markova Jana , Mlcoch Jan
Published: September 2023

Corrosion of weathering steels in outdoor conditions has been observed since their pioneering applications in construction in the 1960s. Changing environmental conditions such as decreasing SO2 concentration and changes in temperature and relative air humidity affect the formation and development of a protective layer of corrosion products on the surface of these steels. The study compares the long‐term corrosion rates of weathering steels according to EN ISO 9224 with the measured rates for various environments in the Czech Republic and abroad, with a focus on sites with high concentrations of chlorides from de‐icing salts. When considering related uncertainties, the corrosion rate models provide estimates in a wide range, and in‐situ measurements can significantly improve corrosion loss predictions. The reliability of bridges made of weathering steels with a well‐developed protective layer is insignificantly affected by corrosion. However, low reliability levels may be experienced in critical details where for example leakage may damage the protective layer of patina.
Seismic performance of RC bridge piers reinforced through FRCM confinement
Authors: Toska Klajdi , Zanini Mariano A. , Faleschini Flora
Published: September 2023

Corrosion of reinforced concrete (RC) structures is one of the main issues concerning existing buildings and especially of infrastructures. Corrosion phenomena, that is induced mainly by carbonatation and by high chlorides concentration, can significantly affect the performance of existing structures. In particular, the seismic performance can be significantly affected. Loss of transversal reinforcement in RC elements can reduce the concrete ductility while corrosion affecting bending reinforcement reduces the lateral load‐bearing capacity of RC elements. To enhance the performance of corroded elements and extend service life of deteriorated structures confinement is one of the most effective and commonly used techniques. This paper investigates the deterioration of the seismic performance of a RC bridge affected by corrosion and retrofitted through FRCM confinement. Different deterioration and retrofitting scenarios are combined and seismic fragility curves are computed for each case. Finally, time‐variant seismic reliability profiles are used to evaluate the best retrofitting scenario and intervention time to maximize reliability gains.
A Bayesian Framework for Simulation‐based Digital Twins of Bridges
Authors: Arcones Daniel Andrés , Weiser Martin , Koutsourelakis Faidon‐Stelios , Unger Jörg F.
Published: September 2023

Simulation‐based digital twins have emerged as a powerful tool for evaluating the mechanical response of bridges. As virtual representations of physical systems, digital twins can provide a wealth of information that complements traditional inspection and monitoring data. By incorporating virtual sensors and predictive maintenance strategies, they have the potential to improve our understanding of the behavior and performance of bridges over time. However, as bridges age and undergo regular loading and extreme events, their structural characteristics change, often differing from the predictions of their initial design. Digital twins must be continuously adapted to reflect these changes. In this article, we present a Bayesian framework for updating simulation‐based digital twins in the context of bridges. Our approach integrates information from measurements to account for inaccuracies in the simulation model and quantify uncertainties. Through its implementation and assessment, this work demonstrates the potential for digital twins to provide a reliable and up‐to‐date representation of bridge behavior, helping to inform decision‐making for maintenance and management.
Buckling analysis of steel members by extension of EC‐3 methods in bridge girders under Patch Loading
Authors: Micelli Francesco , Maci Lorenzo , De Vitis Fabiano Alex
Published: September 2023

The buckling “General Method” of EN 1993‐1‐1 and EN 1993‐1‐5 can be applied to solve problems characterized by non‐uniform geometries and complex stress fields. A typical example occurs during the incremental launching of bridge girders with slender web panel subjected to patch loading. However, this method does not explicitly provide the most critical verification point of a structural element and does not allow to consider the mechanical interaction between instability modes. The objective of the study is the development of a novel methodology that can solve these important special design issues, using a completely automatic process by linear static and linear buckling analyses only. The procedure provides the definition of a slenderness parameter for each point of the structure, in order to avoid the nonlinear analyses with imperfections permutation (as described in Annex C of EN 1993‐1‐5) that require a high computational effort. This pointwise slenderness parameter indicates not only where the slenderness is maximum in each buckling mode, but also the slenderness in other points of the structural elements. This would allow to consider the interaction between global and local buckling, with the definition of an equivalent slenderness parameter for buckling modes coupling.
Assessment of existing bridges: difficulties and challenges following the Italian experience
Authors: Buttarazzi Francesca , Chiaia Bernardino , Marano Giuseppe Carlo , Palmisano Fabrizio
Published: September 2023

Many Italian bridges were built more than 50 years ago and are subjected to significant phenomena of deterioration that in some cases, especially in presence of hidden structural defects due to design or construction errors, have triggered catastrophic collapses. The current situation would require in‐depth analyses to be carried out on all infrastructures to assess the current level of safety, according to in‐force national standard, and to define appropriate construction or operational interventions. However, taking account of the large number of infrastructures, the necessity to define the priorities for detailed assessments arises and, this is why the recent Italian ‘Guidelines for risk classification and management, safety assessment and structural health monitoring of existing bridges’ includes, for the first time in Italy, a stepwise approach with increasing level of detail. In this article the main difficulties and limitations arisen in recent assessments of existing bridges according to these guidelines are discussed. The aim is to highlight either if they can be solved e.g. by improving the guidelines and/or the current codes of practice, or if they should be taken into account when setting the acceptable level of risk and the relevant assessment and rehabilitation requirements.
Inspection and condition assessment of existing overpass, Sofia, Bulgaria
Authors: Jiponov Alexander
Published: September 2023

That paper describes the activities related with an inspection and condition assessment of existing bridge over a railway line in Sofia, Bulgaria. The structure is part of important transport connection between two major residential areas and the Owner wants to enlarge. The aim is to build a new bridge parallel to the existing one and then to refurbish the old one due to its poor exploitational condition. In the assessment report, it is included scanning with UAV (Unmanned Aerial Vehicle) and making of Digital Twin of the structure. The registration of the damages and the identifying of maintenance problems is based on a Visual inspection, NDT Tools and Building Information Model. The quality control assessment of the bridge is based on PI's and KPI's and then two scenarios are elaborated for further action – Reference and Preventive.
Experiences in assessment, replacement and repair of external tendons
Authors: Weiher Hermann
Published: September 2023

The paper presents experiences with damages that occurred when using external tendons. Reason for these damages could be both technical deficiencies of a tendon system (system = components, design, corrosion protection, installation, stressing etc.) or simply human mistakes. Damages often could occur at deviators and anchorages, since forces are transferred to the structure there and the tendon is loaded in transverse direction. Damages will be presented, explained (why it is a damage), which measure had been taken and of course also advice for the future (lessons learned). The damages occurred on site or during testing of external tendon systems. Hence, the paper shall help the reader/attendant to understand sensitivity of external tendons. Furthermore, to these damages experiences with replacement (mainly cutting of the old tendon) of external tendons with flexible filler mass are shared. “Experience” focusses mainly on the de‐installation, re‐installation, grouting and stressing process. Topics that will be covered are:

‐ Improper design and/or installation of deviators and subsequent damages to the tendon sheath

‐ Torsional strand failure due to improper deviation at stressing anchor

‐ Limitations of the tendon path

‐ Deficient encapsulation of the prestressing steel

‐ Tendon force measurement options
Analysis of the Joint Effects of Thermal Stresses and Corrosion on Integral Abutment Bridges
Authors: Contento Alessandro , Aloisio Angelo , Xue Junqing , Quaranta Giuseppe , Briseghella Bruno , Gardoni Paolo
Published: September 2023

The corrosion of reinforced concrete structures in coastal areas turns out to be very severe and can extend significantly in windy zones. Additionally, frequent temperature changes and, above all, exposure to extreme temperatures might induce wider cracks and micro‐cracks in concrete structures which, in turn, might accelerate the diffusion of corrosive agents. Motivated by this evidence, the present study aims at verifying the sensitivity of integral abutment bridges to the combined effect of thermal stresses and corrosion. Preliminary results show that a high thermal stress may amplify the negative effects of corrosion but also that the bridge used for the case study is more sensitive to thermal stresses than to corrosion.
Nonlinear probabilistic structural assessment: Findings from Austrian and Czech bridges
Authors: Novák Drahomír , Strauss Alfred , Novák Lukáš , Lehký David , Šomodíková Martina , Lipowczan Martin , Slowik Ondřej , Doležel Jiří , Pukl Radomír , Sattler Fabian , Apostolidi Eftychia
Published: September 2023

Consideration of uncertainties in bridge structural engineering is a growing topic because it provides valuable information on the reliability of bridges in time while addressing life‐cycle aspects. Utilization of nonlinear finite element method (NLFEM) and Monte Carlo (MC) type simulation is essential for modelling of the concrete bridge random behaviour and its reliability assessments. This contribution describes keystones of a complex methodology for statistical, reliability and risk analyses of concrete structures including advanced nonlinear finite element analysis, uncertainty propagation and degradation modelling. It presents virtual simulation used on the way from assessment of experimental results to reliability analysis of a bridge structure, based on randomization of nonlinear fracture mechanics finite element analysis. Keystones of complex methodology are material parameters identification, nonlinear computational modelling, uncertainties propagation, surrogate modelling, degradation modelling, and safety formats. The paper describes methodology and for a routine complex assessment utilizing developed software tools and practical application of the approach for selected case studies of concrete bridges from Austria and the Czech Republic.
Monitoring and data‐informed assessment of steel bridges ‐ lessons learned from a case study
Authors: Abspoel‐Bukman Linda , Vliet Agnieszka Bigaj‐van , den Besten Caroline , Joostensz Ostar
Published: September 2023

To support the asset owners and operators, in the IM‐SAFE project a framework for life‐cycle asset management has been developed, highly interrelated with the framework for data‐informed safety assessment. A practical decision‐making process has been proposed, aiming at enable proactive maintenance of transport infrastructure, supported by data from monitoring, inspection and testing. The decision making flow, which is a part of the proposed decision‐making process, describes the different stages of the assessment of new and existing structures, focusing on various levels (network, system and component) and taking into account the available data.

This paper presents a case study which demonstrates application of the decision making flow for the Galecopper bridge in the Netherlands where corrosion related damage near the anchorage of the stay cables has been discovered during inspection and on which structural health monitoring (SHM) has been applied for diagnostics and support of the asset management. The paper discusses the factual application of the theoretical decision making procedure on different conceptual levels, adding additional dimension to the decision making flow, based on the practical experience and lessons learned (retrospective).
STRUCTURAL HEALTH MONITORING OF CURVED ROADWAY BRIDGES THROUGH SATELLITE RADAR INTERFEROMETRY AND COLLAPSE SIMULATION
Authors: Farneti Elisabetta , Meoni Andrea , Natali Agnese , Celati Simone , Frascella Carmine , Lupi Maria Cristina , Cavalagli Nicola , Venanzi Ilaria , Salvatore Walter , Ubertini Filippo
Published: September 2023

This paper presents the application of a Structural Health Monitoring (SHM) strategy for bridges affected by slow deformation phenomena to a curved roadway bridge undergoing slow landslide‐induced movements. The chosen multidisciplinary approach is based on the combination of remote sensing data through satellite Synthetic Aperture Radar Interferometry (InSAR) and structural analysis up to collapse investigated through the Applied Element Method (AEM). The results of the application to the considered case study demonstrate that the integration of the displacement information obtained through InSAR technique with the numerical analysis allows for improving the comprehension of the health state of the bridge undergoing slow movements and identifying potentially critical conditions for the structure.
Uncertainty of the crack width model based on fracture of concrete
Authors: Cervenka Vladimir , Rimkus Arvydas , Gribniak Viktor , Cervenka Jan
Published: September 2023

A reliable crack width assessment is a basic part of the sustainability control of the reinforced concrete structures subjected to corrosion degradation. The uncertainty of the concrete cracking model based on a finite element method and nonlinear fracture mechanics is investigated. The parameters of numerical model, such as the finite element mesh size and amount and arrangement of reinforcement are the subject of a case study. The uncertainty of the crack width model is verified on the experimental data from the tests of reinforced concrete beams. The constitutive model of crack propagation is based on the smeared cracks. The effects of numerical discretization as well as dimensional simplification are shown.
Influence of strengthening interventions on the structural performance of a Maillart‐type arch bridge: the case of “Ciolo Bridge” in the South of Italy
Authors: Micelli Francesco , Perrone Daniele , Aiello Maria Antonietta
Published: September 2023

Recent collapses of existing bridges occurred worldwide demonstrated the need of risk mitigation strategies. The failure of existing bridges can be attributed to many reasons: unexpected external actions due to both natural and anthropogenic catastrophes, materials degradation, increased traffic loads, inadequate original design or construction, lack of maintenance. In this context, it is remarkable that a significant percentage of the existing infrastructures has reached its nominal service life, requiring the allocation of relevant resources for their assessment, repair and upgrading. This study investigates the structural performance of a Maillart bridge built in 1960s in the South‐East of Italy. Due to its exposure close to the sea, the bridge has been subjected to a significant degradation, which asked strengthening interventions over the years. A detailed survey and tests were performed to investigate the mechanical properties of structural materials and detailing. A structural analysis was led by considering the original configuration and the retrofitted one. The results of the numerical analyses are shown and discussed in the paper, also by assessing the safety levels of the bridge and the effectiveness of the strengthening interventions occurred during the service life.
FIRE MODELLING AND STRUCTURAL ASSESSMENT OF CONCRETE LININGS OF UNDERGROUND STRUCTURES
Authors: Cardellino Enrico , de Silva Donatella , Bilotta Antonio , Perović Darko , Rios Oriol , la Mendola Saverio , Nigro Emidio , Andreini Marco
Published: September 2023

The structural fire safety of tunnels is a highly debated theme at international level. Car accidents in road tunnels, failures on the power lines in railway tunnels [1,2] and electrical related issues of technological installations in underground research infrastructures can lead to trigger a fire. Fire due to cars, trains and combustion of cable insulations can be considerably dangerous. Fire in such infrastructures causes the stress increases and the losses of bearing capacity in the exposed concrete linings. Thus, in presence of a relevant fire risk, both new and existing underground structures need to be assessed. This paper shows the analyses carried out on the cavern UX15 of the ATLAS experiment, located at the Point 1 of the Large Hadron Collider (LHC) of CERN – Meyrin, Switzerland. The structural fire assessment of tunnels requires to model the lining restrain conditions, the related structural resistance and the spalling phenomena. This modelling is done by Finite Element Method (FEM) code taking into account the spalling in advanced thermo‐mechanical analyses. The shell elements have been used due to their relatively conservative temperature distribution predictions, the acceptable accuracy of the displacement estimates, and a reasonable computational burden.
Evaluation of the pull‐out test to determine the residual prestressing in concrete bridges.
Authors: Pannuzzo Paola , Titton Michele , Furlan Matteo , Tecchio Giovanni
Published: September 2023

In the context of existing post‐tensioned concrete bridges, a reliable assessment of load carrying capacity is still a challenging issue. The effective concrete compressive strength is related to the degradation process of post‐tensioned cables which cannot be detected by visual inspection only. Currently, in‐situ test methods combined with destructive techniques have been used as common methodology to assess either the concrete compressive strength and post‐tension cables losses. Yet, in‐situ tests are indirect approaches, and can be affected by several uncontrolled factors, playing a misleading role in strength determination. In this perspective, the paper aims to firstly introduce a theoretical background of pull‐out tests with their developments and limitations. Then, configuration test has been discussed to obtain reliable strength relationship, with emphasis on post‐installed inserts for pull‐out test. The main current standard provisions have been compared. This study intends to set the basis to test existing post‐tensioned concrete bridges with modified pull‐out test, having no effects on the structural integrity.