bluuebunny/crossref_metadata_2025 huggingface dataset:
Key performance requirements for objective assessment & through‐life management of structures
Authors: Strauss Alfred , Bergmeister Konrad , Vliet Agnieszka Bigaj‐van , Rodríguez Ana Sánchez , Daró Paola , Zimmermann Thomas
Published: September 2023

The overall process in the life cycle assessment is the condition control of new or existing structures respectively. This is necessary for safeguarding the condition of a structure during its lifetime, and includes condition survey, performance assessment as well as for the evaluation of maintenance strategies. Usually deterministic performance prediction models that describe the future condition through a functional correlation between structure condition characteristics, such as the age of the structure, and the characteristics of mechanical, chemical and physical processes are used to capture the deterioration processes in the life cycle analyses. With increasing experience with the use of surveying technologies for acquiring information related to the current condition of bridges there is an ongoing shift towards data‐informed approaches to condition control. The identification and implementation of key performance indicators may improve existing assessment methods within management system of transport infrastructure. The IM‐SAFE project aims to characterize and systematize performance indicators for bridges. Based on these project outcomes, in this contribution, the systematized performance indicators for bridge systems are be presented and a case study is used to show how performance indicators can be coupled with risk‐based performance requirements, data‐informed assessment methods, inspection and monitoring concepts.
Strategies for low limit maintenance thresholds and condition states for bridge structures
Authors: Strauss Alfred , Bergmeister Konrad , Vliet Agnieszka Bigaj‐van , Daró Paola , Zimmermann Thomas , van Meerveld Hendrik
Published: September 2023

The objectives of asset management are to ensure secure service of the objects and/or network, to preserve the infrastructure capital and to maintain the function through their life cycle. Maintenance activities should preserve the performance and future serviceability in such way that an adequate level of reliability with respect to performance requirements applicable to the structure under consideration is preserved. Hence adequate and low limit maintenance should guarantee reliability, safety functionality, availability, maintainability, health and security, as well as environmental and economic performance at the politically agreed level of service. In order to arrange resources, the concept of condition‐states and minimum maintenance thresholds are widely used in context of maintenance planning in many European countries. However, there is no uniform approach defining and rating the condition‐states and setting the low limit maintenance thresholds. In general, national authorities or individual operators are using their own developments which consequently lead to different levels of service. In many cases, the models and criteria used are based on country‐specific experience with implementation of condition‐based maintenance strategies. Moreover, in some European countries, preventive maintenance uses both condition‐based and scheduled maintenance strategy, with certain maintenance measures carried out in a condition‐based manner and some other measures are planned/fixed at certain intervals. In this contribution based on the outcomes of IM‐SAFE project, maintenance concepts, condition‐state definitions and low limit thresholds of maintenance strategies of European countries will be presented, discussed and compared. In addition, a special focus is given to apply sustainable measures and to develop maintenance strategies respecting the European green deal scopes.
Scrutinizing the Performances of Hybrid ANN Models for Forecasting Condition of Bridges
Authors: Elshaboury Nehal , Ben Seghier Mohamed El Amine , Abdelkader Eslam Mohammed , Zayed Tarek
Published: September 2023

Bridges all over the world are vulnerable to severe deterioration agents meanwhile their maintenance budgets are being tightened. This state of affairs necessitates the establishment of an autonomous deterioration model to predict the performance condition of bridges. This research paper explores the implementation of a set of intelligent data driven models to analyze the future condition ratings of bridge decks. These models comprise support vector machines, Gaussian process regression, regression tree, back propagation artificial neural network, Elman recurrent neural network, cascade forward neural network, long short‐term memory network and deep convolutional neural network. The performance comparison is carried out using five evaluation metrics of root mean squared percentage error, mean absolute percentage error, root mean squared error mean absolute error and relative absolute error. The models herein are developed and validated using the structural deterioration information retrieved from the National Bridge Inventory (NBI). It can be argued that the developed deterioration model could be implemented by departments of transportation to analyze and monitor the performance condition behavior of bridge components over their useful lifetime.
A Novel Chaotic Optimization‐Oriented Model for Bridge Maintenance and Rehabilitation Planning
Authors: Abdelkader Eslam Mohammed , Ben Seghier Mohamed El Amine , Elshaboury Nehal , Zayed Tarek
Published: September 2023

The rise in percentage of deteriorated bridges coupled with the escalation of maintenance costs call for systematic bridge management systems. Therefore, this research paper introduces an exponential chaotic differential evolution (ECDE) model for optimizing bridge maintenance plans at both project and network levels. The developed optimization model is envisioned on addressing the performance, economic, social, and environmental aspects of bridge maintenance management. In addition, it exploits the use of chaotic sequences to circumvent the critical shortcomings of local minima entrapment and premature convergence encountered by classical optimization metaheuristics. The validity of the developed model is experimented using a comparative analysis of a wide set bridge elements and over a varying multi‐year maintenance plan. Comparison results reveal that ECDE‐based Sinusoidal algorithm improve the performance diagnostics of classical meta‐heuristics by values ranging from 49.2% to 73.1% over the multi‐year maintenance plans. It can be argued that the developed model could benefit transportation agencies in formulating flexible, sustainable, and cost‐effective maintenance strategies in addition to preserving the structural condition of designated bridges in the network.
BIM‐based immersive meetings for optimized maintenance management of bridge structures
Authors: Jahnke Christoph , Jäkel Jan‐Iwo , Bott Dörte , Meyer‐Westphal Markus , Klemt‐Albert Katharina , Marx Steffen
Published: September 2023

Along the long service life of the approximately 65,000 bridges in Germany of more than 50 years, it requires the execution of many meetings under the participation of many different parties. These meetings are still location‐bound and run very manually using analog inventory documentation. For an optimization, further digitization as well as dissolution of the location dependency at the structure, immersive technologies can be used in connection with digital twins of bridge structures.

This article presents an approach for a location‐independent meeting at the bridge structure under the integration and possibility of interaction of all actors and linking of the digital and physical world. A digital building model of the bridge serves as the data basis and immersive technologies such as augmented and virtual reality as the output and interaction technology. In the first section, the status quo is elaborated based on a literature review. This is followed by the presentation of the theoretical concept. In the next step, the concept is implemented and validated by using a real bridge demonstrator. Finally, further development possibilities as well as still existing challenges are derived.

The result of the article shows a concept and the first feasibility of location‐independent meetings in the maintenance management of a bridge by merging the following elements.
Experience and status of instrumented durability monitoring of concrete bridges in Norway
Authors: Hornbostel Karla , Vasshaug Kristin
Published: September 2023

Within the Norwegian Public Roads Administration, the use sensors of durability monitoring (potentials, corrosion rates, resistivity etc.) was first investigated during a research project on a North Norwegian bridge in the beginning of the 1990s. The knowledge earned from this initial test has been used to compile national recommendations shortly after. Still, durability sensors are seldom used on bridges in Norway today, apart from systems for cathodic protection where potential measurements are frequently executed. During the 1990s to 2020s, durability monitoring was several times applied in research projects and results show how sensors effectively can be used to assess corrosion and durability in concrete elements. To promote the use of durability sensors, the Norwegian Concrete Repair Association newly published a guideline on how to use, install and analyze durability monitoring systems.

The paper summarized experience with the use of sensors for durability monitoring on Norwegian bridges and research projects. Today, there is an increasing demand for solutions allowing the automated monitoring for bridge safety and durability. The status and possible further applications of durability sensors on Norwegian bridges are briefly discussed at the end of the paper.
Updated load models for short‐span road bridges in the range of 2‐15 m
Authors: Treacy Mark , Brühwiler Eugen
Published: September 2023

In recent years, increased effort has focused on developing traffic load models for the safety verification of existing road bridges. In Switzerland for example, this was achieved by updating the alpha reduction factors in the Traffic Load Model 1 (LM1) for new bridges (analogous to the Eurocode LM1 alpha factors), providing a practica approach. The enveloping of the maximum simulated alpha factors, which were calculated by applying measured vehicles to different traffic scenarios, spans and bridge cross‐section types, resulted in the updated LM1 in the SIA 269/1 Standard for Existing Structures. The model development considered spans in the range of 10‐80 m and applied dynamic amplifications as a function of the gross vehicle weight. One limitation of the current updated LM1 is that, as a very high proportion of existing road bridges have spans of less than 15 m, the load effects in this short‐span range tend to be overly conservative. This paper studies the load effect behaviour in the longitudinal and transverse directions, based on actual traffic from Weigh‐in‐Motion (WIM) data. The study utilises all WIM data recorded in Switzerland over the last 10 years. Results from three new short‐span load models are presented which, together, envelope the extreme load effects. A parametric study is presented which highlights some conservatism in the existing code load models. Finally, a case study project is presented, in which these updated models were used to verify the structural safety of a historic road bridge.
Toward a BIM‐based procedure for the evaluation of a risk prioritization class of bridge structures
Authors: Casto Milena , Perrone Daniele , Nascimbene Roberto , Micelli Francesco , Calvi Paolo , Aiello Maria Antonietta
Published: September 2023

Building Information Modelling is receiving increasing attention as an emerging technology for enhancing the life‐cycle performance of facilities. The cooperation between all professionals involved in the construction chain allows to reproduce digital twins of the structures including information related to different disciplines, such as structural and architectural aspects. In this context, the use of Building Information Modelling, combined with an automatic tool to predict risk indices, could be particularly useful when dealing with existing bridges due to the significant structural deficiencies recently demonstrated by numerous bridge collapses worldwide. This paper explores the development of a BIM‐based procedure to bring greater value in the design, construction, maintenance, and inspection stages. The procedure is applied to existing bridges and it allows to estimate a structural risk prioritization class of bridges according to maintained activities, periodical inspections, structural detailing and modelling uncertainties. The automatic BIM‐based tool uses a workflow developed in Dynamo, and is able to automatically update the structural risk class and to provide warning if the structural safety index exceed defined thresholds.
Structural Assessment of a Post‐Tensioned Box Girder Bridge affected by Concrete Creep
Authors: Sconocchia Giuseppe Galassi , Mariani Francesco , Meoni Andrea , Ierimonti Laura , Venanzi Ilaria , Ubertini Filippo
Published: September 2023

The behavior of post‐tensioned concrete bridges is often influenced by time‐dependent phenomena, such as relaxation of prestressing steel, creep and shrinkage of concrete. For bridges built using the balanced cantilever method, the evolution of time‐dependent phenomena during the construction phase must be carefully considered. In common practice, the assessment of the structural safety of this bridge typology is a complex task due to the numerous factors and uncertainties involved in the evaluation process. Numerical models can be adopted to perform structural analyses at successive phases over bridges' lifetime, while destructive and non‐destructive evaluation methods are used to gather information to ensure that the numerical model matches the actual behavior of the bridge. In this context, this paper presents the structural behavior assessment of a multi‐span post‐tensioned box girder bridge with vertically prestressed internal joints. A numerical model was constructed to investigate on the effect of creep and construction phases on the actual stress/strain conditions of the bridge. To reduce model‐based uncertainties, compression tests were carried out on concrete cores extracted from the structure and the results of static load tests were used for model validation purposes.
Experimental study on the failure process of large shear key joints based on NDT methods
Authors: Li Shengtao , Casas Joan R. , Chen Xudong , Sun Yangyang , Liu Duo
Published: September 2023

Dry joints with keys are often used in precast concrete segmental bridges (PCSBs) to transfer shear stresses. Large dry joints with keys can often provide greater shear bearing capacity, which can meet the needs of rapid construction and simple assembly. This study focuses on the shear response of super‐sized dry joints with keys under direct shear. Various monitoring methods, including digital image correlation (DIC) and distributed optical fiber sensing (DFOS), were used to systematically study the stress process of large concrete keys. The results show that as the size of the key teeth increases, the shear bearing capacity and ultimate vertical displacement of the specimens also increase. DIC and DFOS techniques provide detailed information on key tooth failure, which is beneficial for subsequent stress analysis of shear keys.
Durability Assessment of the Laureano Gómez Bridge: a Key Element for New Colombian Infrastructure
Authors: Hernandez Juan Daniel Cassiani , Dugarte Margareth , Keβler Sylvia , Arteta Carlos
Published: September 2023

The durability of reinforced concrete bridges is crucial for ensuring their long‐term functionality and safety. Among the various deterioration mechanisms, carbonation and chlorides are the most significant and widespread problems affecting these structures. This paper aims to assess the durability condition of the historical Colombian Bridge “Laureano Gómez”, which has been in service for over 40 years. The condition assessment involved measurements of the concrete cover, carbonation depths, concrete resistivity, compressive strength, crack survey, and visual inspection of the steel surface. Estimating the remaining service life showed that the stay elements are the most prone to steel depassivation due to carbonation, primarily due to low concrete cover and exposure conditions. The insights from this study could provide valuable information for the durability prognosis of the new bridge built next to it.
DENSE SENSING ON ROAD BRIDGES NETWORK: NEW APPROACH TO DATA‐INFORMED ASSESSMENT
Authors: Daró Paola , Alovisi Isabella , Mancini Giuseppe , Longo Monica , La Mazza Dario , Cigada Alfredo
Published: September 2023

Hazards, ageing, damaging, and traffic loads increase are some of the growing risks that bridge infrastructures in Europe face throughout their design life. Key issues of the asset management plan are the safety assessment of existing structures, the prioritization of the interventions and the optimization of the maintenance schedules. As such, to enable appropriate diagnostics and cost‐effective decisions on assessment/repairs, timely and accurate information from monitoring, inspection and testing is essential. This paper outlines the strategic role of SHM systems to identify the actual condition and future performance of the infrastructures, supporting an effective maintenance plan to meet the target reliability requirements. This contribution describes the use of dense sensing on an Italian bridges network of over 100 bridges, to account for monitoring in safety assessment, facilitating the application of proactive maintenance strategies through a deeper knowledge of the structural behaviour over time. Multiple case studies are detailed, where MEMS sensors have been installed with the purpose of monitoring the evolution of deterioration process, supporting a data‐informed structural diagnostics as well as providing evidence of the effectiveness of strengthening interventions.
Future perspectives of standardization for a safe European transport infrastructure
Authors: Allaix Diego Lorenzo , Vliet Agnieszka Bigaj‐van , Mancini Giuseppe , Daró Paola , Strauss Alfred , Bergmeister Konrad , Köhler Jochen
Published: September 2023

Due to insufficient quality control during construction, progressive ageing and deterioration of materials, growing traffic loads and additional risks originating from climate change or man‐made hazards, suboptimal maintenance strategies, an increase of risks to the transport infrastructure seems inevitable. Incidents like the collapse of the Morandi Bridge cannot be singled out: in the last two decades, around 40 bridges in Europe have collapsed or got severely damaged.

Aiming to ensure the safety of the transport infrastructure through the improvement of maintenance policies across Europe, the European Commission opened the call for the Coordination and Support Action (CSA) “Monitoring and safety of transport infrastructure”. The main objective of this Action is to support the preparation of the mandate for CEN standards for maintenance and control of the European transport infrastructure. The execution of this Coordination and Support Action has been assigned to the IM‐SAFE project consortium.

This contribution presents the input proposed by the IM‐SAFE project [1] for future European standards for monitoring, data‐informed safety assessment and proactive maintenance policies for bridges and tunnels, considering the integration of digitalization as enabling technology.
Data driven planning and approval processes of public road construction projects
Authors: Matthei Jonathan , Klemt‐Albert Katharina
Published: September 2023

Planning and approval processes in Germany still take many years in some cases. According to the Federal Ministry for Digital and Transport digitalization must be used to pick up the pace and achieve progress. In this context, digital methods and applications such as a Common Data Environment (CDE) promise to accelerate and increase the efficiency of road construction projects. This paper first provides an illustration of the main purposes and functions of a CDE. This includes an in‐depth study of current national and international regulations. Subsequently, challenges and optimization opportunities related to the planning and approval process are identified. To this purpose, a quantitative research approach questioning employees from state and federal road construction administrations is carried out. This study identifies improvement potentials through a CDE application especially regarding tracing and transparency. According to the study, the planning and approval process needs to get digitalized, simplified and shorten. Therefore, future research needs to address the question of how to implement a cross‐country CDE for planning and approval processes that interfaces with various state and federal systems without displacing them.
Structural collapse assessment of the access bridge to Hydroelectric Plant “Pacífico Mascarenhas”
Authors: Carvalho Hermes , Gomes José , Montenegro Pedro , Correia José , Vilela Paula , Bittencourt Túlio , Oliveira Luiza
Published: September 2023

The steel bridge popularly known as “Ponte da Usina”, is 54 meters long and is composed of 18 modules of 3 meters. Heavy rains that occurred on the night of 5 February 2013 at the top of the Serra do Cipó, caused an increase of the river level “Parauninha” of approximately 15 meters, causing destruction along its banks and the structural collapse of the bridge “Ponte da Usina”. This work describes the general bridge history and damages that have affected the structure in the past, the circumstances and the impacts of the collapse as well as the proposed alternatives for reconstruction of the collapsed bridge.
Modernising a monument: The challenges of strengthening and widening a structurally deficient road bridge under live traffic
Authors: Treacy Mark , Jokisch Frank , Brühwiler Eugen
Published: September 2023

The historic Port Weir Bridge over the Nidau‐Büren Canal in the Canton of Bern, Switzerland, was inaugurated in 1938. This multi‐purpose structure serves as an important road bridge, a mechanised weir, a lock for canal boats, as well as a hydroelectric power station. During inspections in 2018, severe concrete damage and reinforcement corrosion were observed on this protected structure. Immediate temporary reinforcement measures were required as the conformity factors for structural safety at numerous locations were significantly below the minimum requirements. A project specific traffic load model allowed the temporary strengthening works to be limited to a few critical elements, thereby allowing the bridge to be reopened for heavy traffic in 2019 and then fully rehabilitated between 2020 and 2022. The renovation project involved an innovative reinforced UHPFRC strengthening of the existing T‐beam superstructure and a widening of the deck to bring the lane widths up to modern standards. This paper outlines the safety measures and the UHPFRC strengthening concepts applied, as well as some of the key construction challenges associated with maintaining road traffic on the bridge and traffic in the canal lock below the bridge during the construction works. Additionally, the UHPFRC strengthening concept is demonstrated by means of a design example.
Investigation, assessment, strategy for deck widening of existing HWY PT bridges
Authors: Zoratto Nadia , Giovenale Paolo , Buttarazzi Francesca , Lorenzo Alessandra Di
Published: September 2023

Autostrade per l'Italia (ASPI) is planning the upgrading of several highway axis for approx. 150 km in the next years. Most of the original bridges, built around ‘60/‘70, have already been widened in the 90s but should now be widened again. The original decks are often made of a grid of post‐tensioned elements, while the further enlargements were built with different solutions (precast pre‐stressed beams or steel beams).

To assess the material properties and the internal conditions of the post‐tensioned decks, several investigations with non‐destructive and semi‐destructive testing have been carried out, in accordance with Italian Guidelines.

This paper illustrates the main results collected, also highlighting the difficulties encountered to achieve a sufficient understanding of the degradation conditions. The assessment process evidenced that for a large part of the post‐tensioned decks it was more convenient to intervene with the replacement of the existing decks rather than rehabilitate them. The main reasons supporting this choice are explained.
A Coupled Behaviour of Web and Flange on Bending Buckling of the Web of Steel Box Girder
Authors: IKEDA Miku , YAMAGUCHI Takashi , ARAI Shintaro , Hayashi Gen
Published: September 2023

In general, a web of the steel box girder is designed as an independent. However, in actual behaviour, since the web and the flange behave in couple, the web is considered to have a higher bending buckling strength than the designed standard due to the restraint by the flanges. Therefore, horizontal stiffeners for the web of the steel box girder might be omitted. In this study, focusing on the effect of the coupled behaviour of the web and flange on the bending buckling strength of the web of a box girder, FE analyses were carried out of steel box girder model with different structural configuration and of a panel model under identical boundary conditions as the design. From these results, it was found that the web of box girders without horizontal stiffeners have a higher bending buckling strength than the panel model due to restraint by the top of end of the web by the flange. In the case that buckling parameters of the flange are smaller than those critical buckling parameters, the influence of the bending buckling of the web of the box girder on the buckling strength of the flange is slight.
Effect of Surface Coating Condition on High‐friction Organic Zinc‐rich Paints for HSFB Joints
Authors: Zou Ying , Yamaguchi Takashi , Ueno Keita , Hiraoka Shinya
Published: September 2023

With the development of paints, high‐friction organic zinc‐rich paints with slip coefficients more than 0.45 have been advanced, making it possible to obtain more sophisticated and higher quality high strength bolted friction joints. Moreover, comparing to the inorganic zinc‐rich paints used at present, organic zinc‐rich paints are more appropriate for using in situ construction. However, since the application conditions of organic coatings have not been specified, it is recommended that a slip test should be carried out separately for each surface preparation to confirm the slip coefficient. In this study, slip tests were carried out on high strength bolted friction joint specimens to investigate the influence of high‐friction organic zinc rich paint film thickness and surface preparation on the slip coefficient. Furthermore, based on the experimental results, a surface preparation that can consistently produce a high slip coefficient is proposed.
Challenges in corrosion surveys on reinforced concrete structures – practical experiences from more than 20 years
Authors: Schneck Ulrich
Published: September 2023

Corrosion related measurements on reinforced concrete structures are often easy to apply, and many guidelines indicate that a straight and formal handling of the received data is possible. But practical experience advises to be careful, since similar data readings can be caused by very different, even contradicting situations and hence require an individual, distinguished assessment. For example, negative potential values may be caused either by true, chloride induced corrosion or just by extremely wet concrete – without any possibility of active rebar corrosion. For avoiding wrong interpretations and improper repair strategies, the recommended approach is to obtain various, different parameters, including a sound visual and acoustical inspection, and to compare them thoroughly on a common, plausible pattern. The paper gives some examples where usual survey approaches basing on potential mapping and chloride sampling only would have resulted in either not recognizing the extent of corrosion problems properly or in concluding on severe problems that in fact do not exist.
Interoperable, platform independent structural health monitoring with long‐term availability
Authors: Krüger Markus , Pongratz Helmut , Lienhart Werner , Mülleder Thomas , Binder Fritz , Willeke Jan
Published: September 2023

Within the FFG‐project PreMainSHM the area of preventive structural health monitoring is raised to a new level of networked systems. This applies not only to the networking of self‐sustaining sensors and their sensor data, but also to the networking and utilization of relevant information for the building condition assessment and building management. The paper presents and discusses the basic considerations in terms of data models and interfaces of cloud‐based systems to guarantee interoperability between different software systems and long‐term‐availability and accessibility not only of raw but also of and relevant meta and analysed data. The starting point for further developments is provided by the existing technologies of the involved partners, which is a GIS based infrastructure asset management system and wireless as well as fibre optic sensor systems from the authors. In order to obtain information relevant to the building management, suitable analysis and prognosis procedures are discussed. Data models and analysis tools are developed and integrated into an interoperable software framework in order to provide relevant status information that can be either assessed directly by web user interfaces in form of a georeferenced digital twin or that can be used in building management systems.
Virtual Axle Detector: Train Axle Localization based on Bridge Vibrations
Authors: Riedel Henrik , Lorenzen Steven Robert , Rupp Maximilian Michael , Fritzsche Max Alois , Schneider Jens
Published: September 2023

Infrastructure worldwide is facing the challenge of aging bridges and increasing traffic loads. Prolonged serviceability and safety of these structures can be enabled by Structural Health Monitoring (SHM) methods. Knowledge of the actual operating loads is critical for evaluation of the remaining service life. However, direct measurement of the loads is challenging and requires a significant financial investment. Bridge Weigh‐In‐Motion (BWIM) methods use the structural response of bridge structures to determine loads, but generally rely on accurate knowledge of the position of loads as a function of time. Positions can be determined using conventional axle detectors, but their lifetime is limited, and their installation is expensive. To avoid these problems, we propose an improved Virtual Axle Detector (VAD) with Enhanced Receptive field (VADER) that can detect axles for all bridge types using accelerometers that can be placed anywhere along the bridge. The same data set with 3787 train passages recorded on a steel trough railway bridge under real operating conditions was used. Our results show that, in comparison with VAD, VADER reduces the number of undetected axles by over 79% and detects 99.5% of axles with an average spatial accuracy of 4.6 cm.
Fragility analysis of prestressed concrete girder bridges to traffic loads considering tendon corrosion
Authors: Nettis Alessandro , Nettis Andrea , Ruggieri Sergio , Uva Giuseppina
Published: September 2023

The paper is focused on the probabilistic structural assessment of existing prestressed concrete girder bridges accounting for traffic loads. Particularly, this study concerns the fragility of the class of prestressed concrete girder bridges characterized by post‐tensioned tendons built in the 1960‐1970 period. The structural safety of such bridge class can be affected by construction errors involving voids in the ducts and degradation conditions in terms of tendon corrosion which can be hardly detected during on‐site visual inspections. The study applies a fragility analysis algorithm to investigate the probabilistic response under traffic loads considering the uncertainty related to material and geometric variables for different scenarios of tendon corrosion. The algorithm is applied for two typical case‐study configurations of simply supported superstructures. The achieved results can be considered as a basis for future typological studies which can be used as a decision support for transport managers to define risk‐informed refined assessment plans.
Recent failures of external prestressing grouted tendons: when the ducts take on water…
Authors: Germain Didier , Labourie Laurent , Vaurigaud Bastien , Gaillet Laurent , Van Schoors Laetitia , Houel Adrien , Godart Bruno
Published: September 2023

The article describes recent cases of tendon ruptures by corrosion and investigations carried out on some bridges in France. Several causes related to HDPE ducts have been identified such as damages during handling, threading and tensioning of strands, defective connection of the duct to the anchorage, damage during construction or operation, low quality of HDPE material, etc. These cases of tendon rupture exclusively concern ducts injected with cement grout. To our knowledge, no structure built after the application of the 2001 circular [1] (prohibiting cement grout for the injection of external prestressing) is currently exhibiting major disorders.

A warning note on existing structures with external prestressing has been updated by Cerema in November 2018 [2]. It describes the diagnosis methodology based on analysis of documentation, thorough visual inspection, destructive and nondestructive investigations. New non‐destructive techniques such as guided‐wave ultrasonic technique and magnetic leakage field test using permanent magnets and induction coils are presented. Innovative methods of local repair of the ducts are also described. Finally, different protective devices are analysed in terms of worker safety in the event of a sudden failure of tendon.
Structural Condition Classification of Railway Bridge KW51 Before, During, and After Retrofitting
Authors: Al‐Ghalib Ali A. , Mahmoud Sawsan M.
Published: September 2023

A linear classification algorithm for various structural states (before, during, and after retrofitting) of railway steel arch bridge KW51 based on Linear Discriminant Analysis (LDA) of principal components is proposed. The technique is typically employed in other fields, such as genetics, but its use in civil engineering is still limited. The method is applied in two steps, first, the original vibration measurements are projected to a lower dimensional subspace using Principal Component Analysis (PCA). The significant principal components are provided as inputs to LDA to constitute the newly transformed subspace. Joining PCA and LDA improves the performance aptitude of LDA when only first major principal components hold the main signature of the features. The acceleration datasets that represent bridge conditions under train passage on the steel arch railway bridge in Belgium, mentioned as bridge KW51 have been utilized for validation of the algorithm. The outcome of the visualization process is further analyzed using three clustering methods (kmeans, Fuzzy C means, and Gaussian Mixture Modelling). The confusion matrix is used to examine the performance of the clustering methods. The proposed algorithm provides promising results that outperformed other classification methods.
Using distributed fibreoptic sensing to monitor repaired structures reinforced with steel‐patches
Authors: Grefe Hinrich , Stammen Elisabeth , Dilger Klaus , Baudone Tommaso , Arutyunyan Garnick , Baitinger Mascha
Published: September 2023

Adhesively bonded steel patches present a novel approach to strengthen fatigue cracked steel bridges or similar structures. After the repair, the new weld is covered with an adhesively bonded steel patch, redistributing parts of the load and reducing the overall stress in the repaired structure. Unfortunately, this covers the weld permanently and therefore any form of direct, visual inspection is no longer possible. Hence arises the demand for a technical solution to reliably determine the condition of the repaired weld and its reinforcement. Fibre optic sensors using Rayleigh backscatter offer a spatial distributed strain measurement from which a deformation profile can be generated. This deformation profile allows to determine the load distribution between patch and structure and can be used to identify possible changes in the load distribution which can represent a change in the mechanical properties and therefore a possible defect. Having not only the information about the absolute value of the strain but also its distribution, the expected damage can be located and measured. The deformation profile also allows to separate different forms of failure for example a broken weld, adhesive failure within the patched area or sub surface migrating corrosion.
Life‐cycle performance of noise barriers focusing on installation conditions of fasteners
Authors: Granzner Maximilian , Strauss Alfred , Reiterer Michael , Kari Hannes
Published: September 2023

This concept paper discusses the effects of the installation condition of fasteners on the life‐cycle performance of noise barriers. Noise barriers that are erected along high‐speed railway lines are loaded by aerodynamic pressure and suction waves due to the passing trains. As an integral part of railway infrastructures their level of safety must be maintained throughout their entire lifetime. On basis of this concept and study, a potential monitoring‐based approach for the assessment of the life‐cycle performance of NBs is briefly introduced. That monitoring‐based approach finds its place in a holistic four‐stage assessment framework, in other words a progressive four‐stage model in which the information content increases with each model stage and thus successively increases the accuracy of the determined structural conditions at the time of observation and the prediction for the remaining service life of the structure. The objectives of this paper should bring relevant insights for the whole holistic four‐stage model. Depending on how far the degradation of the considered noise barrier has already progressed, the corresponding stage of the holistic assessment concept is activated, which enable infrastructure managers to plan their future investments regarding maintenance, retrofit or rebuilt of noise barriers more economically.
The Challenges of long‐time high‐sampled Structural Health Monitoring: a practical Feedback
Authors: Cartiaux François‐Baptiste , Semiao Jorge
Published: September 2023

Structural Health Monitoring (SHM) systems have been widely used in the last years as integrated tools for the management of civil infrastructures. Some SHM projects now reach significant durations of several years, which induces interesting challenges when they imply numerous sensors with high sampling rates. This paper aims to present feedback on a few real cases of long time SHM on civil structures, performed by OSMOS Group as a SHM service provider. The examples include various types of structures, with concrete, masonry, and metallic bridges as well as tunnels, and address the cases of both wired and wireless autonomous SHM systems, some of them with more than ten years of operation. Issues related to the data flow and storage are described, which represent high volumes of data, since the SHM systems are aimed to assess continuously the dynamic response of the structures with 100 measurements every second. Maintenance and upgrading of the SHM systems along such important durations are addressed also. Finally, the discussion focuses on massive data analysis tools dedicated to long‐time SHM, which enable to reduce the amount of raw data into useful synthetic information for anomaly detection and prognosis.
Load‐carrying capacity of Vierendeel bridges in Mechelen
Authors: Van Bogaert Philippe , De Pauw Bart
Published: September 2023

From 1930 to 1960, in Belgium, steel railway bridges were regularly designed using the vierendeel system. Three railway lines cross the Mechelen‐Leuven canal in the town of Mechelen, providing a unique example of this type of application. Two of these bridges, which were constructed in 1953 were renovated in 2021–2022, including the installation of a new rail fastening. It was discovered that the 1936‐built third and oldest bridge had multiple cracks, mostly in the vertical members of the Vierendeel structure. Furthermore, secondary components like longitudinal beams and cross beams are severely harmed by corrosion. As a result, uncertainty grew over this bridge's ability to support loads. The monuments organization promotes the preservation of these old structures. The material properties, as well as the load‐bearing capacity and the fatigue strength, were evaluated by a thorough experimental and numerical investigation. The results of the examinations suggest that the significant strength variation of the steel components may be the cause of the cracking. It is more likely that cracks developed during the bridge's construction and subsequent repairs than that fatigue is to blame. In conclusion, the arrangement of the three bridges is too special to be destroyed and replaced, and the third bridge may also be sufficiently repaired and rebuilt for long‐term further use.
Repair and Retrofitting of Concrete Bridge Girder Using Epoxy, Micro Mortar, and CFRP Sheets
Authors: Ahmed Khondaker , Moniruzzaman Md , Rupa Kaniz
Published: September 2023

Bangladesh is connected through bridges and many of them are experiencing damages due to the aging of concrete, weathering effect, or excessive loading. Repair and retrofitting of those bridges are becoming inevitable to make them operational. In this study, the damages of a concrete bridge have been investigated through non‐destructive tests and numerical methods. A repair and retrofitting strategy for the damaged girders has been developed using epoxy injection, shrinkage‐compensated micro mortar, and externally bonded Carbon Fiber Reinforced Polymer (CFRP) sheets. The micro mortars are injected inside the large cracks and damaged portions of the girders. The flexural zones of the girders were strengthened using U‐shaped CFRP sheets. Field load tests are also conducted to determine the achieved improvement from the repair strengthening work. Dynamic accelerometers, digital probes, and linear variable differential transformers (LVDT) were attached to determine the actual deflections of the girder before and under loading. Finite Element models (FEM) are developed to validate the field data and determine the shear and flexural resistance of the retrofitted girders. The outcomes show that the retrofitted bridge satisfies the design requirements of the AASHTO‐LRFD guidelines.
A methodological proposal for the analysis of bridges inspections data according to the Italian Guidelines
Authors: Mazzatura Isabella , Natali Agnese , Salvatore Walter , Principi Lorenzo , Morici Michele , Dall'Asta Andrea
Published: September 2023

The question of maintenance and monitoring of bridges gained attention during the last decade, especially in Italy, after some serious collapses. The first emergency phase was the census and the visual evaluation of the state of maintenance and preservation of existing heritage to highlight the critical conditions for security. For this reason, in 2020 the Italian Ministry of Transport and Infrastructure enacts Guidelines, based on a multilevel approach, which allows to save time and resources by deepening the analysis only on the bridges in the worst state of conservation. After two years of inspections, a lot of data had been collected. The data concerns both the geometrical/typological characteristics and the defectiveness of bridges. In the present work, the authors discuss the data of a sample of inspected bridges belonging to some Regions of the Italian infrastructural system trying to analyse them from a statistical point of view. The objective is to standardize an analysis methodology and apply it to a larger number of samples to obtain useful and significant information to refine the inspection procedure and, eventually, to educate algorithms for the a priori provision of the defectiveness level, suggesting a possible prioritization of the bridges to be inspected.
Structural Control and Health Monitoring Contributions to Service‐life Extension of Bridges
Authors: Domaneschi Marco , Martinelli Luca , Cucuzza Raffaele , Noori Mohammad , Marano Giuseppe Carlo
Published: September 2023

Transportation Infrastructure networks are acknowledged as crucial for economic growth, territorial coherence, and social change. Unfortunately, some of this vast system's most important structural elements, like the bridges, are rapidly aging while the load conditions that these systems were designed to withstand are now being exceeded as a result of various threats, including natural disasters and newly discovered man‐made phenomena. Considering that a large amount of the existing bridge stock was built many years ago, if countermeasures are not taken, deterioration phenomena and an increase in service conditions larger than those used in the original design may have contributed to diminishing the dependability level. Hence, it becomes crucial to evaluate the existing status of transportation infrastructure, make predictions about its future state, and safeguard it from outside threats. This contribution focuses on an in‐depth investigation of the impact of Structural Control and Health Monitoring in increasing the structural resilience of transportation infrastructure and subsequently its life‐cycle.
Indicators for the Management of Earth‐Retaining Structures
Authors: Amado João Luís , Pratas M. Alexandra , Monteiro Bernardo , Costa André , Pinheiro Maria
Published: September 2023

The Portuguese national road and railway Network managed by Infraestruturas de Portugal, S.A. comprises over 20,000 earth‐retaining structures throughout Portugal. The company seeks to improve processes through a dedicated management system that aligns with best asset management practices. The system involves data collection, analysis, and action planning based on inspection observations and analysis of structure condition and criticality. The resulting level of risk informs prioritization of subsequent actions. This work focuses on the indicators and processes supporting risk‐informed decision‐making for earth retaining structures.
How to deal with uncertainties in the assessment of the global warming potential of bridges
Authors: Boros Vazul
Published: September 2023

After a brief review of previous studies on the ecological life cycle assessment of bridges, some of the shortcomings of the hitherto used methods are highlighted. An approach is introduced which derives probabilistic models for the global warming potential of four construction materials based on a database of Environmental Product Declarations. The methodology is demonstrated on two case studies, where it proved effective in the assessment of the bridge's ecological life cycle. This allows for a more objective comparison of design choices, also considering the uncertainties in the environmental impact of the materials involved. Consequently, decision makers will be provided with more elaborate data and can therefore make better choices in guiding society towards a greenhouse gas emission free future.