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Aerostatic instability is one of two vital instabilities of wind resistance design for long-span bridges. Traditionally, the aerostatic instability considering aerodynamic and structural nonlinearity is evaluated through finite element methods employing the Newton-Raphson algorithm. However, the Newton-Raphson algorithm cannot track the structural equilibrium path after the first critical wind speeds (zero stiffness point) and the potential post-buckling multi-stability. This study proposes to use the arc-length method to calculate the aerostatic structural deformation for increasing wind speeds iteratively. Arc-length can track the equilibrium force-deformation curve even after the initial critical wind speeds. This study finds out that when the pitch moment curve of the bridge deck has a" turning point" at a large angle of attack, there is possibly more than one equilibrium point (multi-stability) for the same wind speeds. Correspondingly, the bridge deck deformation shape and cable and hangers' internal force along span direction change dramatically at the same wind speed due to aerostatic multi-stability. In the last part of this study, the bridge structure under a turbulent wind field can buckle at a lower wind speed than a smooth wind field because the material yields are caused by large instantaneous deformation. [ABSTRACT FROM AUTHOR]

With rapid industrial development, the overloading of bridges caused by heavy multi-axle vehicles has become a critical problem worldwide. This work conducts a performance-based evaluation for tied-arch bridges subjected to heavy multi-axle vehicles, and a prediction function of the dynamic impact factor (DIF) for tied-arch bridges is proposed considering the bridge frequency, vehicle speeds, and road quality level. Specifically, the main parameters affecting the bridge response were first identified theoretically using a simplified multi-axle vehicle-bridge model. A tractor-trailer mechanical model and a tied-arch bridge model were subsequently constructed and coupled using displacement coordination conditions to explore the characteristics of the bridge response under heavy multi-axle tractor-trailers. Additionally, based on the identified factors, a detailed investigation of DIF was performed using the developed special vehicle-bridge interaction model. Finally, a suggested computational method for predicting DIF of tied-arch bridges was proposed. The results obtained indicate the impact effect of special tractor-trailers on bridges should not be ignored, even at low operating speeds and in good road conditions. Moreover, additional monitoring measures should be placed on the structural components that are sensitive to dynamic responses to regulate responses within an acceptable range. [ABSTRACT FROM AUTHOR]

The combined use of finite element modeling and structural health monitoring is becoming increasingly relevant in bridge maintenance. A growing number of new and old structures is instrumented with different kinds of sensors driven by dedicated hardware and software, while numerical models are used to simulate the response of the structures under various scenarios. This paper presents the monitoring of the Smithfield Street Bridge, one of the oldest and most iconic bridges in the city of Pittsburgh (Pennsylvania, USA). The bridge was instrumented by an independent party, not involved with the research presented here, with strain, displacement, and rotation wireless sensors. A detailed finite element model of one of the spans of the bridge was developed to calculate the strains induced by standardized trucks under pristine and simulated damage conditions. In addition, the model enabled to determine the sensitivity necessary to detect relevant structural changes in the bridge. The results of the numerical analyses were then compared with the results of a test in which a truck of known weight crossed the bridge multiple times. Finally, the data relative to 3 years of uninterrupted monitoring were processed and analyzed to identify eventual anomalies. [ABSTRACT FROM AUTHOR]

Log hauling costs are increased by the presence of closed and posted (restricted weight loading) bridges, as operators are forced to find alternative routes to wood-using mills. The USDA Forest Service Forest Inventory and Analysis (FIA) forest inventory, road network, bridge, and sawmill datasets were obtained for the US state of Mississippi. An 80.5 km buffer was established to define each sawmill's working area, which occasionally extended across state lines. Anetwork analysis derived 129 feasible shortest optimal trucking routes between 46 FIA plot locations and the sawmills. Thirty of these routes had either closed or posted bridges along the shortest path; only 13 viable alternative routes were identified due to distance and posted weight limits. The additional trucking distance for these workable alternative routes averaged 7.1 km. The affected routes and their legal, full payload alternatives were each fitted to atriangular distribution to better understand how costs were impacted by posted or closed bridges. If no regulated bridges were encountered, haul cost across arange of haul rates and distances ranged from $3.50 to $14.40 USD per tonne. Costs were from $3.90 to $16.00 USD per tonne along routes with posted or closed bridges. On average, the cost difference was $0.98 USD per tonne, which was an increase of 12.0%. These findings have implications for road infrastructure maintenance, log trucking, wood procurement, and ultimately the values of standing timber and timberland. [ABSTRACT FROM AUTHOR]

In order to solve the dynamic nonlinear problem of bridge loads and responses during ship collisions, a design method for bridge anti-collision structures based on nonlinear numerical simulation was proposed. The author describes in detail the entire process of collision force evolution, energy conversion, and plastic deformation of the anti-collision energy dissipator, and conducts a comprehensive simulation of it. The experimental results show that when a ship with a mass of 1000 tons collides forward at speeds of 1, 3, and 5 meters per second, the collision depth is 0.23, 1.46, and 3.95 meters, respectively, less than the maximum allowable collision depth of 4.3 meters, and the collision energy dissipator is still in the protective working state for the bridge pier. When a ship with a mass of 3000 tons collides with the collision avoidance energy dissipator at a speed of 3 or 5 meters per second, the collision depth exceeds the maximum allowable collision depth, and the collision avoidance energy dissipator fails, the ship will directly collide with the wharf. The plastic deformation of the anti-collision energy dissipator provided has important reference value for design. [ABSTRACT FROM AUTHOR]

This study introduces an innovative "Big Model" strategy to enhance Bridge Structural Health Monitoring (SHM) using a Convolutional Neural Network (CNN), time-frequency analysis, and fine element analysis. Leveraging ensemble methods, collaborative learning, and distributed computing, the approach effectively manages the complexity and scale of large-scale bridge data. The CNN employs transfer learning, fine-tuning, and continuous monitoring to optimize models for adaptive and accurate structural health assessments, focusing on extracting meaningful features through time-frequency analysis. By integrating Finite Element Analysis, time-frequency analysis, and CNNs, the strategy provides a comprehensive understanding of bridge health. Utilizing diverse sensor data, sophisticated feature extraction, and advanced CNN architecture, the model is optimized through rigorous preprocessing and hyperparameter tuning. This approach significantly enhances the ability to make accurate predictions, monitor structural health, and support proactive maintenance practices, thereby ensuring the safety and longevity of critical infrastructure. [ABSTRACT FROM AUTHOR]

In the bridge technical condition assessment standards, the evaluation of bridge conditions primarily relies on the defects identified through manual inspections, which are determined using the comprehensive hierarchical analysis method. However, the relationship between the defects and the technical condition of the bridges warrants further exploration. To address this situation, this paper proposes a machine learning-based intelligent diagnosis model for the technical condition of highway bridges. Firstly, collect the inspection records of highway bridges in a certain region of China, then standardize the severity of diverse defects in accordance with relevant specifications. Secondly, in order to enhance the independence between the defects, the key defect indicators were screened using Principal Component Analysis (PCA) in combination with the weights of the building blocks. Based on this, an enhanced Naive Bayesian Classification (NBC) algorithm is established for the intelligent diagnosis of technical conditions of highway bridges, juxtaposed with four other algorithms for comparison. Finally, key defect variables that affect changes in bridge grades are discussed. The results showed that the technical condition level of the superstructure had the highest correlation with cracks; the PCA-NBC algorithm achieved an accuracy of 93.50% of the predicted values, which was the highest improvement of 19.43% over other methods. The purpose of this paper is to provide inspectors with a convenient and predictive information-rich method to intelligently diagnose the technical condition of bridges based on bridge defects. The results of this research can help bridge inspectors and even non-specialists to better understand the condition of bridge defects. [ABSTRACT FROM AUTHOR]

This article presents a summary of the damage observed in bridges in the regions affected by the 6 February 2023 Kahramanmaras, Türkiye earthquake sequence. A bridge database was developed based on the observations from multiple reconnaissance groups that visited the bridges. These reconnaissance groups collectively visited 140 individual bridges that were subjected to various intensities of ground shaking. The severity of the observed damage ranged from no damage to total collapse. The types of damage to bridge components mainly included cracking and shifting of abutments, failure of pier cap shear blocks, shifting or dislodging of bearing pads, cracking of girders and loss of prestress, plastic hinging at pier bases, residual pier drift, and distress to deck surfaces, handrails, and carried utilities. Recorded and estimated seismic intensity measures are presented for each bridge site, and statistical information and correlations were developed considering the intensity of shaking, bridge parameters, and observed damage. Observations from a few visited sites are presented as case studies to illustrate the common failure mechanisms. The bridge database and presented results are expected to serve as a reference for further analysis, such as statistical verification, correlation, or damage estimations, and discussion regarding the mitigation of the observed vulnerabilities of bridges in Türkiye and those with similar construction worldwide. [ABSTRACT FROM AUTHOR]

Bridges may develop breathing cracks under excessive overloading vehicles, while conventional beam models are ineffective in analyzing the effect of spatial distribution of these cracks. This study proposes a data‐driven detection model with the consideration of spatial distribution of breathing cracks that can detect the multiple damage locations and degrees of breathing cracks in plate‐like bridges. Firstly, a 2D vehicle–bridge interaction model containing breathing cracks is established, and the damage indicator, contact point displacement variation (CPDV), is calculated using vehicle acceleration data. Next, a dataset with CPDV as the input feature is generated using the finite element method to train the CatBoost‐based damage prediction model, which considers the random distribution of single and multiple cracks, as well as the influence of different vehicle speeds. Finally, by calculating the CPDV related to the actual bridge and feeding it into the trained model, the location and degree of the damage can be predicted. The numerical simulation results demonstrate that this approach can accurately detect complex crack information under various vehicle speeds and exhibits robustness against road roughness. A laboratory experiment further confirms the effectiveness, applicability, and feasibility of this method to multiple damage locations and degree of breathing cracks. [ABSTRACT FROM AUTHOR]

Translation abstract Mattensteg, rehabilitation and relocation of a 150 year old frame bridgeAt the existing Mattensteg – a 150 year old riveted truss‐girder steelbridge, a condition survey in 2005 revealed that the local concrete bridge deck was in poor condition. Based on this assessment and the bridge‘s previous service life, it was decided to carry out a comprehensive renovation of the bridge. At the same time, the AWEL (Amt für Abfall, Wasser, Energie und Luft des Kantons Zürich) planned to renew the Platzspitzwehr. In recent years, access for maintenance work on the weir has been via the Platzspitz, as the Mattensteg cannot be used by heavy vehicles. This is unsatisfactory for the park with its protected plane trees. It was therefore decided to build a new service bridge at the site of the Mattensteg for the construction and future maintenance work. However, as the existing Mattensteg is a listed building, the existing old truss bridge was to be retained, moved some 80 m upstream and rebuilt. The reinforcements were riveted analogously to the existing construction. Due to the protected status of the building, the new piers will be built in the original style with stairs. As a result, the footbridge is no longer accessible to cyclists, wheelchair users or maintenance vehicles. The construction costs for the relocation, the construction of the new supports and piers as well as the restoration of the bridge amount to CHF 2.5 mio. [ABSTRACT FROM AUTHOR]

Seismic vehicle‐bridge interaction (SVBI) is the study of vehicle‐bridge interaction (VBI) in the presence of earthquake excitation. SVBI is an interdisciplinary problem of increasing importance to the design and safety of railways. This study deploys a consistent methodology to decouple the vehicle‐bridge system and solve independently the bridge and vehicle subsystems, bypassing multiple challenges the seismic response analysis of a coupled vehicle‐bridge system entails. The proposed approach builds upon the previously established Extended Modified Bridge System (EMBS) method for decoupling vehicle‐bridge systems (in the absence of earthquake excitation). Its premise is to first characterize and then assess the relative importance of the VBI effect on the bridge and vehicle responses and replicate it by modifying the pertinent uncoupled equations of motion (EOMs). The formulation deployed accommodates multi‐degree of freedom models for both the vehicle and bridge and can thus tackle complex systems. The analysis examines the ability of the proposed decoupling approach to predict the response of a realistic system vehicle‐bridge system under a suit of historical earthquake records. The decoupled results are in excellent agreement with the coupled solutions for all earthquake records and scenarios (i.e., earthquake excitation solely in the transverse direction of the bridge, as well as in both the transverse and vertical directions simultaneously). [ABSTRACT FROM AUTHOR]

During strong earthquakes, the footing of a rockable bridge can temporarily and partially separate from the support. This rocking motion can activate rigid‐like motions, reducing the deformation along the height of bridge piers and leading to smaller bending moments. As a result, rockable footing has been considered as a possibility for low‐damage seismic design of structures. For bridges, the seismic‐induced interaction between girders and adjacent abutments can change the structural dynamics due to the impeded girder movements. Although bridges with rockable footing, for example, the South Rangitikei viaduct, have been constructed, research on rockable bridges mainly focused on a single‐segment case. Physical experiments on rockable bridges considering pounding are very limited. In this work, large‐scale shake table experiments were performed on a two‐segment bridge model with abutments. The cases without pounding and with girder‐girder pounding alone were considered as references to help interpret the results. To investigate the consequence of footing rocking, the results of the rockable bridge on a rigid base were compared to that of the fixed‐base bridge. The study reveals that compared to a fixed‐base segment, the girder of a rockable segment is easier to move laterally. This change in dynamics due to rocking leads to less maximum pounding forces and thus reduces the damage potential to girders and abutments. [ABSTRACT FROM AUTHOR]

With the continuous development of high‐speed railway (HSR) construction technology, many HSR bridges are close to near‐fault earthquake zones. Due to the short warning time for earthquakes occurring in these areas, the scene of trains running on the HSR bridges under earthquakes will become more and more common. In order to effectively evaluate the train running safety performance on the HSR bridge under earthquakes, an improved model for the nonlinear simulation of the high‐speed vehicle‐track‐bridge (VTB) coupling system under seismic shaking is proposed. The commercial finite element software was utilized for the general modeling of track‐bridge structure, and nonlinear hysteric behaviors of key components were realized by using the local nonlinearity correction method. By adopting the unconditional stable explicit dynamic integration algorithm and an efficient wheel–rail contact model, an explicit dynamic solution framework is established. It can efficiently solve the nonlinear coupled vibration of the VTB system under earthquakes. Finally, based on the improved model developed in this paper, the influence of hysteretic behaviors of bridge bearings on the nonlinear coupling vibration of the VTB system under near‐fault earthquakes is discussed. [ABSTRACT FROM AUTHOR]

Due to the lack of connecting facilities, residents in the Gampong Blang Mirou and Kumba Kec. Bandar Dua have to travel via another route. Although proposals to the district government are submitted every year, a response was received in 2018. In 2018, the construction of the Blang Mirou--Kumba steel truss bridge was carried out using the DAK budget, the tender process for this development package used a budget of 14 billion Rupiah. The purpose of this research is to determine and analyze the increase in social interaction and economic growth as a result of the construction of the bridge connecting Gampong Blang Mirou - Kumba District. Bandar Dua Kab. Pidie Jaya. The method used is descriptive qualitative. The data sources used are primary data and secondary data. The research uses data obtained through interviews, observation, and documentation. Based on the results of the research and findings in the field, the conclusion is that the implementation of this policy can provide practical implications for the people of Pidie Jaya Regency, especially the people of Gampong Blang Mirou and Gampong Kumba as well as the Pidie Jaya Regency Government so that social interaction between the regions and the regional economy both increases. An interesting finding was that when the road was widened to build a connecting bridge, the community gave their land for free without having to be compensated by the government. [ABSTRACT FROM AUTHOR]

In order to study the seismic vulnerability of high-speed railway bridges in the nearshore area during their lifetime, based on a long-span prestressed rigid frame bridge of a high-speed railway, considering the pile-soil interaction, the vulnerability of components of the bridge under different seismic directions is calculated by quantifying the damage index and using the increment dynamic analysis (IDA). The second-order boundary method is adopted to establish the full-life seismic vulnerability surface of the bridge system, and the time-varying seismic vulnerability after the durability damage during the service life of the nearshore high-speed railway bridge is studied. The research results show that under the design seismic action of the long-span bridge of high-speed railway, the probability of slight damage to the bridge system in the longitudinal and transverse bridge directions is 46.4% and 15.1%, respectively; the probability of severe damage is small, and reaches 18.7% and 9.7% respectively under the rare earthquake action. The seismic vulnerability of the bridge in the longitudinal direction is greater than that in the transverse direction. When the pile-soil interaction is considered, the system vulnerability increases, but the increase is small. Under the rare seismic action in the longitudinal direction of the bridge, the exceedance probability of severe damage increases by 1.1%. During the whole life cycle of the bridge, when the service life is 100 a, the exceedance probability of slight damage under the design seismic action of the bridge is 17.1% higher than that of the new bridge. The seismic vulnerability of the high-speed railway bridge gradually increases with the increase of the service time. The durability damage in the later stage of the service life is more serious, and the seismic vulnerability increases obviously. However, the complete failure of the high-speed railway bridge does not occur basically throughout the whole life cycle. [ABSTRACT FROM AUTHOR]

Investigations on bonded stiffeners in steel and composite bridges Numerous bridges are in poor condition. In particular, resistance to plate buckling is a problem. Strengthening of buckling‐prone sections in steel bridges is often difficult due to non‐weldable steels and the additional notch effect from conventional joining techniques. The use of adhesives for fixing stiffeners allows material‐friendly reinforcement of buckling‐prone steel sections. Prior to practical application, numerous questions must be answered with regard to the detailing of the stiffeners, the stress on the adhesive layer due to inhibiting buckling, the load‐bearing capacity of the adhesive layer, the resistance to aging and fatigue. On the basis of numerical and experimental investigations, a simple fracture condition could be developed which allows a design of the adhesive layer's load‐bearing capacity. A sufficient stiffening effect of the bonded stiffener is given as long as the adhesive layer's load‐bearing capacity is sufficient. The aging and fatigue behaviour was investigated in basic tests. It was possible to define boundary conditions that enable resistance for a limited time, but there is still need for further research in this field. [ABSTRACT FROM AUTHOR]

Evaluation and strengthening of existing bridges – historical outlines and findings regarding the Hessian road bridge inventory Two short histographical sketches introduce the concepts of refurbishment, condition and load‐bearing capacity assessment between 1700 and 2010 and take a look at the development of the recalculation of existing bridges. Based on project sketches, the hidden safety features of existing road bridges are worked out and procedures for achieving efficient structural bridge strengthening are presented. The focus is on the determination of real object‐specific traffic load models, calibrated structural analyses and additive and non‐destructive strengthening methods. Some critical comments on planning acceleration and the current approval system, together with the demand that bridge construction should be reflected in the common objective of "traffic", broaden the definition of strengthening holistically. This offers the opportunity to stimulate a discussion about the sensible handling of existing bridges as part of our road infrastructure. [ABSTRACT FROM AUTHOR]

Many arch bridges have been built in near-fault regions around the world and may be affected by fling step, which is the permanent ground displacement caused by the long-period pulse within the frequency content of an earthquake. This study investigates the effect of fling step on reinforced concrete deck-type arch bridges with short to medium spans. Three-dimensional non-linear models of three existing reinforced concrete arch bridges in Iran, with span lengths of 23, 35 and 60 m, were developed. The structures were subjected to seven near-fault earthquakes in longitudinal and transverse directions, once with the fling-step pulse included and once with it removed. The results showed that fling step has a noticeable effect on the seismic response indicators investigated, but may increase or decrease the seismic demand. The maximum curvature in the presence of fling step in relation to that without fling step ranged between 0.54 and 2.06. Unseating in the longitudinal direction was most sensitive to the fling step, and showed a more than 200% increase in some cases. Effects of the fling step were correlated with the ratio of the period of the fundamental mode of vibration of the structure to that of the fling-step pulse. [ABSTRACT FROM AUTHOR]

The main objective of this study is to assess and contrast the efficacy of distinct spatial prediction methods in a simulation aimed at optimizing the embodied energy during the construction of prestressed slab bridge decks. A literature review and cross-sectional analysis have identified crucial design parameters that directly affect the design and construction of bridge decks. This analysis determines the critical design variables to improve the deck's energy efficiency, providing practical guidance for engineers and professionals in the field. The methods analyzed in this study are ordinary Kriging and a multilayer perceptron neural network. The methodology involves analyzing the predictive performance of both models through error analysis and assessing their ability to identify local optima on the response surface. The results show that both models generally overestimate the observed values. The Kriging model with second-order polynomials yields a 4% relative error at the local optimum, while the neural network achieves lower root mean square errors (RMSEs). Neither the Kriging model nor the neural network provides precise predictions but point to promising solution regions. Optimizing the response surface to find a local minimum is crucial. High slenderness ratios (around 1/28) and 40 MPa concrete grade are recommended to improve energy efficiency. [ABSTRACT FROM AUTHOR]

Bridges are one of the most important infrastructures because they are a link between 2 different points that have an impact on a country's economy. The impact of bridge construction can be controlled with good design and design. In this paper, the author will model the planning of the lower structure of the bridge using Revit Software as a form of Building Information Modeling (BIM) technology. This paper uses references from international and national journals taken from Google Scholar. The references obtained are useful in making a literature review that has a relationship with the topic discussed by the author, namely bridges. It is known that the use of BIM technology is very helpful and makes it easier for engineers in the implementation of a construction project. Therefore, this research enhances the understanding and application of digital tools in civil engineering projects, contributing to innovation in construction practices. [ABSTRACT FROM AUTHOR]

Vehicle scanning methods are gaining popularity because of their ability to identify modal properties of several bridges with only one instrumentation setup, and several methods have been proposed in the last decade. In the numerical models used to develop and validate such methods, bridge damping is often overlooked, and its impact on the efficacy of vehicle scanning methods remains unknown. The present article addresses this knowledge gap by systematically investigating the effects of bridge damping on the efficacy of vehicle scanning methods in identifying the modal properties of bridges. For this, acceleration responses obtained from a numerical model of a bridge and vehicle are used. Four different scenarios are considered where vehicle damping, presence of road roughness, and traffic on the bridge are varied. Bridge damping is modeled using mass-proportional, stiffness-proportional, and Rayleigh damping models. The impacts of ignoring bridge damping or considering one of these damping models on the modal frequencies and mode shapes identified using the vehicle response are investigated by comparing the results. The outcomes of the numerical analysis show that ignoring bridge damping in vehicle scanning applications can significantly increase the efficacy of these methods. They also show that the identifiability of the bridge frequencies and bridge mode shapes from the vehicle response decreases significantly when bridge damping is considered. Further, the damping model used impacts which bridge modes can be identified because different damping models provide different modal damping ratios for each mode. The results highlight the importance of correctly simulating damping behavior of bridges, which is often ignored, to be able to correctly evaluate the efficacy of vehicle scanning methods, and they provide an important stepping stone for future studies in this field. [ABSTRACT FROM AUTHOR]

Steel corrosion is by far the biggest durability issue for many reinforced concrete bridge structures worldwide. The columns in these bridges can be critical, especially for seismic resistance. In this study, glass-fibre-reinforced-polymer bars were investigated as an alternative to steel for sustainable and resilient bridge construction. As lateral reinforcement is more susceptible to corrosion, and structures fully reinforced with fibreglass bars display softer responses with lower shear and flexural capacity, fibreglass spirals and longitudinal steel reinforcement were used in the tested columns. The experimental programme included the design, construction and seismic testing of full-scale (508 mm diameter) and half-scale (356 mm diameter) columns. The other variables investigated were the axial load and the amount and spacing of spirals. For both column sizes, fibreglass spirals provided increasing confining pressure to the concrete core with increased deformations. For the full-scale columns, no adverse size effects were observed in comparison to the half-scale columns. The columns produced large ductility and energy dissipation. Results from selected representative specimens are presented here to establish the feasibility of using fibreglass spirals in circular bridge columns. Resilience can thus be built into new columns through innovative durable fibreglass lateral reinforcement, with similar if not superior behaviour to steel-reinforced columns. [ABSTRACT FROM AUTHOR]

Multi-span bridges having a bidirectional ductile diaphragm consisting of buckling-restrained braces (BRBs) can provide resilient bridges with damage-free columns, at low cost, while minimising displacement demands to levels that can be easily accommodated. Towards the goal of better understanding the behaviour of this type of bridge and its advantages, a parametric analysis was performed considering regular multi-span simply supported bridges with variations in pier stiffness, BRB target displacement, BRB yield displacement and numbers of spans. The bridges were analysed in the longitudinal direction. BRBs were designed using non-linear response history analysis. The demands of the designed bridges were analysed to understand the influence of the various parameters considered. The proposed system was able to reduce the demands in piers so as to keep them elastic and limit the displacement demands in expansion joints (making it easier to prevent unseating in retrofit situations). It was also found that, according to fatigue damage calculations, it is not necessary to replace BRBs after an earthquake. [ABSTRACT FROM AUTHOR]

A new consolidation system for prestressed reinforced concrete (PSRC) beams of girder bridges is presented and evaluated. The system consists of two arch-shaped steel trusses placed alongside the lateral faces of the beam to be consolidated. The arches develop longitudinally along the entire span of the beam and in elevation using the available height of the PSRC cross-section. The consolidation system is characterised by its own external constraints, independent from those serving the pre-existing element. The efficiency of the system with respect to variable parameters is examined, focusing on the ratio between the load discharged by the consolidation system and the total applied load. Referring to a case study, consolidation of a PSRC beam adopting the proposed system is compared with the usually adopted external prestressing technique. The cross-sectional properties of the steel arch-shaped trusses are defined by means of a structural optimisation process using a genetic algorithm to identify the minimum steel consumption. Finally, a preliminary cost–benefit analysis is performed for the proposed solution and compared with other commonly adopted techniques. [ABSTRACT FROM AUTHOR]

The Canadian highway bridge design code (CHBDC) uses the concept of a target reliability index for evaluating the load-carrying capacity of existing bridges. This index, which is based on risk to human life, is related to three aspects of uncertainties inherent in a bridge: element behaviour, system behaviour and inspection level. Analysis is yet another uncertainty in bridge evaluation. It is assumed that all bridge inspections are manual. Citing examples of tests on many instrumented bridges, another level of inspection is proposed, carried out with the help of electronic instruments and tests under controlled vehicle loads. Simple additions to the clauses of the CHBDC are proposed, which can be used to determine the optimum load-carrying capacities of existing bridges where structural monitoring information is available. [ABSTRACT FROM AUTHOR]

Soil–structure interaction can significantly affect the seismic vulnerability of systems through several mechanisms that depend on the mutual effects of the soil properties and the structural characteristics. In this work, a probabilistic-based approach was applied to evaluate such effects on the fragility of an isolated bridge representing a typical Californian highway bridge. Analytical fragility curves were developed using OpenSees, implementing hysteretic materials and advanced plasticity models to represent non-linearity. The mutual non-linear effects of soil deformability and isolation on the system (soil–foundation–structure) were assessed by considering several limit states for the column ductility and the deck displacement. [ABSTRACT FROM AUTHOR]

Bridges are fundamental links for the movement of goods and people and bridge damage can thus have significant impacts on society and the economy. Earthquakes can be extremely destructive and can compromise bridge functionality, which is essential for communities. Evaluation of bridge functionality is thus fundamental in the planning of emergency responses and socioeconomic recovery procedures. It is especially useful to define parameters to assess investments in bridge infrastructure. Resilience is a key parameter that can identify decision making procedures necessary for recovery investments. In this regard, resilience can be defined as the rapidity of a system to return to pre-disaster levels of functionality. This aim of this work was to assess the lack of robust analytical procedures for quantifying systematic restoration for earthquake-damaged bridges, to provide a link between the assessment of resilience and its application in decision making approaches. The proposed methodology (called seismic resilience for recovery investments of bridges) uses functionality–time curves that allow quantification of resilience along with readable findings for a wider range of stakeholders. The results presented in this paper should be of interest to multi-sectorial actors (i.e. bridge owners, transportation authorities and public administrators) and could drive interdisciplinary applications such as the assessment of recovery techniques and solutions. [ABSTRACT FROM AUTHOR]

Foundation scour has been a reason for several cases of river-bridge earthquake-induced failure during recent decades. However, practising engineers often do not consider its direct effect on the seismic design procedure of such structures. The cavity around a bridge foundation is a random phenomenon depending on several uncertain parameters. This study provides a probabilistic platform to investigate the effect of random scouring on the seismic performance of a particular bridge. The procedure is implemented on an existing multi-span reinforced concrete bridge. To this end, the Monte Carlo simulation technique is utilised to generate samples of the random variables of the scour model to develop the scour hazard curve. A common type of reinforced concrete multi-span bridge is considered as a model. The Latin hypercube sampling method is employed to generate random scouring scenarios in the finite-element model, including uniform and non-uniform scour. Then, fragility curves are developed utilising cloud dynamic analysis. The results reveal that the scouring pattern is one of the most crucial sources of uncertainty. In most circumstances, uniform scour scenarios are more effective than the average of non-uniform cases. However, in some specific patterns, the effect of non-uniform scouring is dominant. [ABSTRACT FROM AUTHOR]

When traffic flows pass through existing bridges, the dynamic effect of the vehicle loads increases due to the local surface damage rather than the entire roughness level of the bridge deck. This study presents a method for evaluating a dynamic impact factor (IM) from a bridge dynamic response under a traffic flow considering the local surface damage. The random axle loads of traffic vehicles under the deteriorated roughness conditions are presented using an input load time-history applied to each discretized deck node of a finite element bridge model. The amplification ratios of the root mean square of the simulated acceleration under nominal road surface conditions with respect to the specified IMs in the design stage are calculated. The relationship between the ratios and IMs is determined to evaluate the dynamic impact factors under any surface roughness condition. The method is validated by applying it to two existing bridges with different road surface damage and traffic conditions. The results show that the IMs depend on both the traffic loading and bridge surface roughness conditions. Under the same traffic flow conditions, the values increase when the road surface damage increases. However, the increases in the IMs vary according to the location of the surface roughness deterioration in both of the target bridges. [ABSTRACT FROM AUTHOR]

Bridge maintenance is a highly intricate task that involves considering a wide range of factors in order to achieve optimal decisions that align with multiple objectives, criteria, and the entire lifecycle of the bridge. While physics-informed analysis, such as the finite element method (FEM), can simulate complex and closely coupled scenarios, such as bridge structural analysis, it cannot account for some loosely coupled discrete factors, which could be addressed by ontological reasoning. Therefore, this paper presents a knowledge-driven decision-making framework that combines static knowledge reasoning with dynamic FEM analysis results to support holistic bridge maintenance decisions. One significant contribution of this research is the development of a comprehensive bridge maintenance ontology that incorporates knowledge derived from bridge maintenance standards. Another key contribution is the ability to employ complex runtime rules-based reasoning to tackle intricate bridge maintenance scenarios. To enable automatic knowledge-driven reasoning, an integrated workflow is developed to orchestrate semantic modeling with numerical modeling through a Python-based Web Ontology Language application programming interface (OWL API). This integration facilitates the efficient orchestration of the framework. A case study is presented to demonstrate the potential for the developed framework in assisting with the complex holistic decisions required for bridge maintenance. [ABSTRACT FROM AUTHOR]

To improve shear capacity, as well as reduce on-site casting and steel consumption, a novel Y-shaped perfobond rib (Y-PBL) shear connector with ultra-high-performance concrete (UHPC) grout was proposed. The shear behavior of the Y-PBL shear connector was investigated by six groups of pushout specimens. Their failure modes, load–slip curves, load–separation curves, strain analysis, and shear transfer mechanisms were discussed. Subsequently, finite-element analysis (FEA) models were established to study the effect of parameters on the shear behavior of the Y-PBL shear connector, as well as to compare the shear capacity contributions with straight-shaped PBL (S-PBL) shear connectors. Analytical models were proposed to predict the shear capacity of the Y-PBL shear connector. The results reveal that the proposed Y-PBL shear connector has superior shear capacity and stiffness. The contribution of the perforating rebar is minor compared with the end-bearing effect of UHPC. The analytical predictions agree well with the experimental and FEA results. This study can be used to guide the design and application of the Y-PBL shear connector in steel-concrete composite bridges. [ABSTRACT FROM AUTHOR]

Seismic intensity measures (IMs) provide a link between the seismic hazard and the dynamic response of structures subjected to earthquake shaking. The spectral acceleration at the first and usually dominant vibration mode, Sa(T1), is a popular choice for building structures. Meanwhile, the IM selection for bridges is non-trivial since they do not typically possess a single dominant mode. Even for ordinary bridges with a dominant mode, the behavior can change significantly in each principal direction through the activation, or yielding, of its different components. This study examines the performance of a novel IM that incorporates ground motion directionality and structure non-linearity in this context: the nnth percentile of all rotation angles of the inelastic spectral displacement, Sdi,RotDnn. This evaluation is carried out within the context of an ordinary bridge structure and is compared with other conventional IMs used in regional risk assessment of bridges. The case study bridge utilized is a highway overcrossing located in California with two spans and a continuous prestressed reinforced concrete box girder deck section. A large ground motion set was selected from the NGA-West2 database, and incremental dynamic analysis was carried out on the structure to assess the IM performance to characterize collapse. The results indicate that Sdi,RotDnn performs very well compared to other IMs for the bridge structure and could be a prudent choice to characterize inelastic response of bridges with several possible mechanisms in different principal directions. Also, using the RotD50 definition, typically used in ground motion models, showed a 17.3% increase in efficiency compared to RotD100 definition typically used in engineering practice. [ABSTRACT FROM AUTHOR]

This study investigates traffic load as a cause of urban decay and failure on a highway in Nigeria, using Ibadan–Oyo road as a case study. This study identifies road failure as a major city nightmare that affects the well-being of urban dwellers in the study area. The Ibadan–Oyo road is a segment of the major road intersection that connects the southern part of Nigeria with the north. The methodology for this study involves a well-structured questionnaire administered to road users to elicit primary data on the factors and effects of urban decay due to traffic load. A total of 100 Questionnaires were randomly distributed among the road users (vehicular and pedestrians) of the Ibadan–Oyo road. In all, 92 questionnaires were returned. These were analyzed using the Relative Importance Index (R.I.I) and basic statistical tools, to better understand the trend of responses. The results from the study show the factors that enable traffic load and failure include the road as a major route to various parts of the country, not obeying driving laws, poor driving habits, and poor/absence of road pavements. The stress of heavy vehicles on the Ibadan–Oyo road also proves to be a major factor which leads to incessant failure of the road, even after maintenance or reconstruction has been carried out. The failure of this urban infrastructure and the poor road networks leads to many accidents, acute vehicular fuel consumption, waste of time, breakdown of vehicles and road rage. To drastically reduce the impact of infrastructural decay and failure on highways, this study suggests the following: construction of separate routes for trucks and other heavy vehicles, provision of various parks along travel routes for heavy vehicles, and use of a weighing bridge to regulate the range of axle load, replacement of flexible paving with a more rigid design for increased strength and road life span, proper rehabilitation and reconstruction of the failed segment, provision of an alternate railway system to convey heavy goods and also reduce the stress on road transport, in-depth training of vehicle drivers and traffic personnel and lastly, enlargement of the road width. [ABSTRACT FROM AUTHOR]

Steel bridge designers and erectors primarily rely on approximate methods, such as 1D line girder analyses and 2D grid analyses. For curved or skewed bridges, this can give erroneous indications of the structure's true behaviour. Refined methods of analysis, such as 3D shell modelling, aim to bring a significant change in the practice of bridge engineering. By moving the industry away from simplistic design assumptions, refined analysis methods lead to more accurate, less conservative results, which in turn brings true benefits such as improved structural safety and increased economy. In this paper, several case studies on curved plate girder and tub girder bridges are presented, which cover the full bridge life cycle, from erection of the steel structure and placement of the concrete deck, down to live load analyses using influence surfaces and load rating. The case studies will be modelled with mBrace3D, a dedicated FEA software for curved steel bridges. [ABSTRACT FROM AUTHOR]

Suspension bridges, such as stress-ribbon, are among the simplest structural bridge systems and have the lowest structural height. The flexibility of these elegant bridges poses great challenges for designers to minimize their deformability under asymmetrical operational loads. Due to the small initial sag, such load-bearing structures also cause significant tensile forces, which requires them to have large cross-sections and massive anchor foundations. This paper analyzes an innovative suspension steel bridge structure combined with a string and a cable. More attention is paid to asymmetric loading as this is more relevant for suspension structures. The new structure is studied numerically and experimentally. It is established that the string stabilizes the displacements of the bridge under asymmetric loading. The stabilization efficiency is proportional to the value of the pre-tension force of the string. The obtained results reveal the behavior of the structure and enable an evaluation of the accuracy of the numerical results, as well as the applied modeling. In addition, the experimentally obtained results allow the evaluation of more aspects of the behavior of the new bridge, which will be useful in further studies of this type of structures. [ABSTRACT FROM AUTHOR]

Applying unmanned aerial vehicles (UAVs) and vision-based analysis methods to detect bridge surface damage significantly improves inspection efficiency, but the existing techniques have difficulty in accurately locating damage, making it difficult to use the results to assess a bridge's degree of deterioration. Therefore, this study proposes a method to generate panoramic bridge surface images using multi-view images captured by UAVs, in order to automatically identify and locate damage. The main contributions are as follows: (1) We propose a UAV-based image-capturing method for various bridge sections to collect close-range, multi-angle, and overlapping images of the surface; (2) we propose a 3D reconstruction method based on multi-view images to reconstruct a textured bridge model, through which an ultra-high resolution panoramic unfolded image of the bridge surface can be obtained by projecting from multiple angles; (3) we applied the Swin Transformer to optimize the YOLOv8 network and improve the detection accuracy of small-scale damages based on the established bridge damage dataset and employed sliding window segmentation to detect damage in the ultra-high resolution panoramic image. The proposed method was applied to detect surface damage on a three-span concrete bridge. The results indicate that this method automatically generates panoramic images of the bridge bottom, deck, and sides with hundreds of millions of pixels and recognizes damage in the panoramas. In addition, the damage detection accuracy reached 98.7%, which is improved by 13.6% when compared with the original network. [ABSTRACT FROM AUTHOR]

This paper quantified the seismic resilience (SR) of different bridge classes by performing three-dimensional advanced numerical simulations in Opensees. SR was calculated by performing the seismic resilience for recovery investments of bridge (SRRIB) methodology that is based on the quantification of the losses and the repair time. In particular, the probabilistic-based methodology developed by the Pacific Earthquake Engineering Research Center (PEER) was implemented to produce fragility curves by considering the longitudinal displacement of the deck as the reference parameter. The recovery process was modeled using a linear formulation due to the unavailability of information from past earthquakes. SR for the selected bridge classes was calculated in terms of the seismic intensities to be applied for decision-making procedures during pre- and postearthquake assessments. [ABSTRACT FROM AUTHOR]

This paper proposes a mathematical framework for optimal retrofit and recovery strategies of bridge networks. The pre-earthquake and postearthquake management of the highway systems is addressed considering performance objectives based on seismic resilience and life-cycle costs. Structural capacity of vulnerable bridges and traffic performance of the transportation network are investigated accounting for the effects of aftershocks by state-dependent fragility curves informing cumulative damage scenarios. Optimal intervention sequences are identified under uncertainties related to bridge damage levels and mainshock–aftershock sequences based on a biobjective optimization problem aiming to maximize network resilience and minimize costs associated with pre-event retrofit and postrepair restoration activities. [ABSTRACT FROM AUTHOR]

Changes in vehicular loading over time have caused some concrete slab span bridges to rate poorly when considering modern truck weights, which leads to load posting and restrictions that in turn lengthen trucking routes. A potential way to allow heavier vehicles to cross these bridges would be to increase the load rating by utilizing a more accurate live load distribution factor generated from field testing and computational modeling. The focus of this study was to determine the live load distribution factor for two slab span bridges using results from live load testing and plate model analysis. Field testing utilized a suite of instrumentation, and simple isotropic or orthotropic plate models of the slab span bridges were validated with field data to further investigate live load distribution. Field-test estimates of equivalent width computed using displacement data were more precise than those using strain data, but modeling indicated that strain data may better capture the distribution of stresses in the slab. Despite significant visible damage, the field bridge behaved more like an isotropic plate. AASHTO equivalent widths were conservative when compared with those computed from the field results and isotropic model for single-lane truck loading but were similar to each other for multilane loading. However, model results also indicated that the equivalent width depends on the load configuration, such that single-axle loading will be concentrated into a narrower strip compared with tandem loading. In addition, an orthotropic slab will further narrow the equivalent width compared with an isotropic slab, such that AASHTO equivalent widths may no longer be conservative for single-axle loading of a slab so degraded that it may be treated as effectively orthotropic. [ABSTRACT FROM AUTHOR]

Single-column bridges are widely used for urban overpasses and highway bridges. Rising overturning incidents have exposed the vulnerability of this type of bridge, which is inherently susceptible to overturning collapse. A typical solution is to provide vertical restrainers at the beam ends. However, the current antioverturning calculation method was incapable of coordinating deformations between bridge components, which may have severe consequences in engineering practice. For example, the Huahu Viaduct, located in Hubei, China, experienced overturning failure even after applying vertical restrainers, which was not anticipated according to the current engineering experience. In this work, we proposed a modified calculation method regarding deformation coordination to predict the ultimate overturning capacity, verified through forensic investigation and numerical analysis, of the Huahu Viaduct. Compared with bridges without restrainers, overturning failures start with the failure of restrainers. Failure mechanisms are analyzed, including critical states and overturning features. Further comparison indicates that the practical method overestimates the ultimate overturning capacity by up to 38%, while the proposed method provides a more effective reference to this problem in engineering practice. [ABSTRACT FROM AUTHOR]

The blast resistance of a typical two-lane steel girder highway bridge structural system was modeled using a nonlinear finite-element approach that considered material damage, fracture, and separation. Critical blast scenarios were based on field observations of terrorist attacks on bridges in Iraq, while system failure was defined in terms of practical emergency serviceability criteria used on actual blast-damaged bridges. The blast resistance of various design parameters was assessed, including the number of girders, deck concrete strength, reinforcement ratio, slab thickness, girder and reinforcement yield strength, girder sectional dimensions, and pier column width. The presented approach uniquely quantifies structural system blast resistance in terms of the charge weight that can be applied at different locations until failure. A sensitivity analysis was conducted to determine the most influential design parameters. It was found that system blast capacity was primarily influenced by the number of girders and girder yield strength, while additional significant parameters were deck compressive strength, deck thickness, web stiffener width, and girder depth. Secondary parameters were deck reinforcement ratio, girder flange, and web thickness, while deck reinforcement yield stress was found to be insignificant. Based on the results, recommendations for improving blast resistance are provided. [ABSTRACT FROM AUTHOR]