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Climate change exacerbates the structural deterioration of concrete highway bridges, posing a threat for them to resist vehicle collisions. However, the investigation into the safety of highway bridges under the joint effects of climate change, deterioration, and collisions caused by heavy vehicles is lacking. This paper presents a practical framework for assessing the lifetime fragility of concrete highway bridges exposed to both heavy vehicle collisions and climate change-accelerated corrosion. The main challenge of applying fragility-based approach in this framework lies in developing surrogate demand models, which traditionally requires extensive time-consuming simulations of vehicle-bridge collisions using finite element methods. To overcome this, an impact force time history model is proposed as an efficient alternative to represent collision demands on bridge piers by heavy vehicles. Implementation of this model has demonstrated a remarkable reduction of approximate 90% in computational time requirements compared to the collision analysis. The framework enables the generation of fragility surfaces at any given time throughout the bridge's service life. The effectiveness of the framework is demonstrated using an example highway bridge, and fragility surfaces are generated for various climate scenarios. The results indicate a rise in the probability of collapse, from 0.4% for a structurally sound bridge to 87.2% after 80 years of chloride exposure when subjected to a heavy vehicle collision with an impact velocity of 100 kph and a truck weight of 36 t. Additionally, the impact of climate change is evident, further increasing this probability to 97.4%. These findings underscore the significant roles that both corrosion and climate change play in influencing the vulnerability of concrete bridges to heavy vehicle collisions. Addressing these factors in collision design and lifetime assessment is essential for ensuring the structural resilience and safety of bridges over time. • Evaluation of bridges' vulnerability under the combined impacts of heavy vehicle collisions, corrosion, and climate change. • Development of an impact force time history model as a substitute for dynamic collision simulations. • Characterization of bridges' collision resistance, incorporating site-specific chloride exposure and climatic conditions. • Analysis of bridges' time-dependent failure probabilities during collision events throughout its lifespan. [ABSTRACT FROM AUTHOR]

Thermal loads can cause significant stresses in some structures such as bridges or arch dams. Studies in arch dams show that thermal loads have the most significant effect for causing cracking than other service loads. Moreover, since researches on climate change announce that mean temperature on Earth is expected to increase, the assessment of the impact of the future temperature increase on the structural behaviour of sensitive infrastructures should be considered. This paper proposes a methodology for the assessment of the impacts of global warming on the structural behaviour of infrastructures. The paper links future climate scenarios to the thermal, stress and displacement fields of the structure. The methodology is illustrated with a case study: La Baells arch-dam. The expected stress and displacement fields of the dam under several future climatic scenarios were computed by finite element models. Concrete temperature are expected to increase up to 5.6 K, which will make annual average radial displacements increase in some cases even more than 100%. Tensile stresses are also projected to change and should be adequately monitored in the future. Finally, several adaptation strategies are outlined. [ABSTRACT FROM AUTHOR]

Highlights • A comprehensive review on resilience assessment of coastal bridges is presented. • The discussion covers wave forces, bridge response, fragility and recovery models. • The discussion outlines advances and challenges in resilience assessment research. Abstract Coastal bridges are susceptible to severe damage due to wave-induced forces during extreme events such as coastal flooding, hurricanes, storm surges and tsunamis. As a direct impact of climate change, the frequency and intensity of these events are also expected to increase in the future. This paper presents a comprehensive review of a four-phase resilience assessment of coastal bridge structures, namely, (i) characterization of external wave-induced forces, (ii) structural response of bridges, (iii) vulnerability assessment of damaged components, and (iv) post-disaster recovery. The four comprehensive modules are adopted from the classic framework of PEER PBEE and constitute the integrated knowledge needed for the prediction of the resilience of infrastructure under extreme wave-induced loads. The study also presents new expressions for resilience restoration that simultaneously account for the time, resources (cost) and environmental impacts of different recovery options with variable importance levels to different stakeholders. [ABSTRACT FROM AUTHOR]

The paper describes a risk analysis of the economic impact of damage to metal roofing of a typical contemporary (new) Australian house subject to extreme wind loading. The failure modes considered are roof cladding and batten-to-truss connection failures, with the effect of defective construction also considered. Monte-Carlo simulation and structural reliability methods are used to stochastically model spatially varying pressure coefficients, roof component failure, and load re-distribution across the roof. This spatial reliability analysis enables fragility curves to be developed that relate likelihood and extent of roof cover loss to gust wind speed. The annual economic risk is up to 0.3% of house replacement value. A typical house with construction defects increases economic risk more than sixfold when compared to the defect-free house. There is a 10% chance that a changing climate will increase expected losses for houses in Brisbane and Melbourne by 6–18% over the next 50 years. [ABSTRACT FROM AUTHOR]

• Detailed flood analysis of roadway bridge exposed to extreme events with scour and debris. • Scour examination is performed in concurrence with hydrodynamic and debris loading. • Ambient-vibration data is used for model calibration. • Two types of soil-structure interaction modelling are considered and compared. • Debris-induced amplification of scour is examined, and it is shown to increase the failure potential of the bridge. Hydraulic actions on bridges are a leading cause of failure, especially due to the occurrence of scour erosion. Due to climate change, flooding and scour risks are exacerbating for bridges worldwide, leading to a significant stress burden on asset management agencies. Assessing structures for scour has received significant attention in recent years, however, there are few studies which investigate the influence of scour on the components of a bridge to understand how various elements interact. Moreover, the presence of debris loading, which can occur due to flooding causing debris to become lodged at structures, has not received significant attention. Debris can worsen scour conditions and increase hydraulic loading on a bridge. In this paper, an analysis of the response of various components of a roadway bridge when exposed to extreme flooding is conducted. The influence of scour and debris on hydraulic loading, internal forces, modal periods, and utilization ratios of various bridge components is ascertained. A numerical model is developed using OpenSees employing two different methods to model the soil-structure interaction. Results for several flooding scenarios show how the various bridge elements are influenced by variations in water height and velocity, scour depth, and presence of debris. [ABSTRACT FROM AUTHOR]

This paper proposes a methodology for the rational assessment of lifetime costs on tall buildings due to hurricane-induced damage along the US Atlantic coastline accounting for plausible future warming climate scenarios. The hurricane simulation is based on Vickery’s empirical model. Initially, regression errors in Vickery’s model are discussed; some adjustments are proposed to enable hurricane simulation in future climates. After verification of the hurricane model’s ability to simulate the results of the United States historical hurricane database, simulation of hurricane activity in future climates is examined. The warming climate scenarios are reproduced from the results of the community earth system model, maintained by the National Center for Atmospheric Research (NCAR). Three different future climate scenarios, RCP2.6, RCP4.5 and RCP8.5, are considered. The influence of warming climate on two quantities, relevant to wind engineering, is examined: hurricane frequency and hurricane intensity. It is found that, in a warming climate environment, the hurricane frequency and hurricane intensity may vary depending on the RCP scenario. Therefore, the probability distribution of the wind speed in hurricane-prone areas of the United States, both coastal and interior areas, will also be influenced by the RCPs. The numerical methodology for computing wind speed probability distribution in a future warming climate, influenced by the various RCP scenarios, is subsequently coupled with an existing approach for structural performance analysis against wind hazards to predict the indirect effect of future warming climate on the structural intervention costs (i.e. repair costs), induced by the damaging winds. A 180-m tall benchmark building, located in Miami (Florida, USA), is used as one example of application in conjunction with a series of structural fragility curves, derived from a recent study for the same structure. The evaluation of lifetime intervention costs is later expanded to demonstrate the ability of the proposed methodology to predict hurricane wind damage, if the location of the structure is moved to several other cities along the Atlantic coast of the United States. [ABSTRACT FROM AUTHOR]

• The inherent adaptivity describes how structures can be fundamentally manipulated. • This can be analyzed using actuation influence matrices. • They present quantitative information on the inducible structural states. • Their rank corresponds to the number of manipulatable linearly independent states. • This information / method can be used to design adaptive structures intuitively. New approaches and technologies are needed to counter the effects of climate change and mitigate the depletion of material resources. A possible solution are adaptive load-bearing structures, i.e., structures that are equipped with sensors, actuators and control units, enabling the structure to optimise its current stress state. This requires new research regarding the overall structural design of material- and emission-efficient adaptive structures. Existing approaches employ sensitivity matrices or optimality criteria in optimization formulations to design adaptive load bearing structures and discuss the quality of the design based on the results. This paper presents the method of actuation influence matrices, which are a type of sensitivity matrix that can be used quantify the inherent adaptability of a structure. The aim is to develop an intuitive design method for adaptive structures. After a brief derivation of the influence matrices, the methodology is illustrated using three basic bracing systems – a truss, a frame and a diagonally braced frame – as example, demonstrating the relationship between structural topology and inherent adaptability. While the assessment of an adaptive structure's quality depends on the specific use case and control objective, it is proposed that truss systems are good candidates for adaptive structures due to their inherent adaptability. [ABSTRACT FROM AUTHOR]

Winds generated by non-synoptic events such as those from tornadoes, microbursts or gust fronts, that are non-stationary or transient in nature and extreme in magnitude, can cause major damage to flexible structures. In this paper, a time-domain method is used to simulate the response of a long-span bridge subject to winds generated by a particular type of non-synoptic wind phenomenon such as a microburst to assess the vulnerability of the bridge to such winds. The self-excited or motion-induced and buffeting or turbulence-induced wind loads on the structure were modeled and simulated by Rational Functions and buffeting indicial functions, respectively. Wind from a translating microburst was simulated using empirical relationships that were derived from measurements of a laboratory-simulated microburst and the bridge response calculated to compare it with those induced by an equivalent straight-line wind that is used for structural design. It is shown that microburst induced structural vibration could be larger or smaller than the vibration induced by straight-line wind of equivalent magnitude depending on the relative size of the microburst with respect to the bridge span. [ABSTRACT FROM AUTHOR]

Abstract: Glulam structures in service may exhibit considerable moisture induced stresses perpendicular to grain that may affect the load-bearing capacity. An option to enhance the low tensile strength of glulam perpendicular to grain is the use of self-tapping screws, which has shown promising results in constant climates. In varying climates, however, the performance of such screw reinforcements is currently not well understood. The present paper reports results of both experiments and numerical simulations investigating the effect of self-tapping screws on moisture induced stresses arising in glulam exposed to single wetting and drying climate changes. It is shown that during wetting, the screw reinforcement significantly reduces the maximum tensile stresses arising in the cross section centre. With screw distances from 70 to 210mm, stress reductions by 70–30% are achieved (compared to unreinforced glulam beams). The tensile stresses arising between the reinforcing screws depend not only on the screw distance, but also strongly on the cross section width and the annual ring pattern of the laminates. During drying, the additional restraint caused by the reinforcing screws resulted in a slight increase of the tensile stresses at the cross section border. These were, however, rather low compared to the tensile stresses arising during wetting. [Copyright &y& Elsevier]

Abstract: In variable humidity conditions, wood absorbs or desorbs moisture from the air. Unless the change in humidity is very slow, this will develop moisture gradients in the wood sections. These gradients will develop stresses due to constrained swelling or shrinkage strains. These stresses are named moisture-induced stresses. The present paper investigates the main parameters affecting such moisture-induced stresses, including the type of climate, the size of the timber cross-section, and the type of protective coating. A first attempt to identify moisture-induced stresses in different European climatic regions was made. For each climatic region, relative humidity and temperature histories were identified, and characteristic and mean values of yearly and daily variations were calculated. Using a finite element model implemented in Abaqus, the moisture content and stress distribution were computed on different timber cross-sections exposed to the climatic regions and protected with different types of coating. A Fickian moisture transfer model was used to compute the moisture distribution, and a mechanical model for time-dependent behaviour of wood was implemented to calculate the corresponding stress distribution. The variation of moisture was found to result in stresses of magnitudes that would probably cause cracking of wood in the perimeter of any uncoated cross-section size. The use of a protective coating, however, reduced considerably the moisture-induced stresses, and can be regarded as an effective protective measure to avoid cracking due to humidity variations. Considering European climates, Northern climates were found to result in higher surface tensile stresses than Southern climates. [Copyright &y& Elsevier]

Abstract: Atmospheric CO2 is a major cause of reinforcement corrosion in bridges, buildings, wharves, and other concrete infrastructure in Australia, United States, United Kingdom and most other countries. The increase in CO2 levels associated with global warming will increase the likelihood of carbonation-induced corrosion. Moreover, temperature rises will increase corrosion rates. Clearly, the impact of climate change on existing and new infrastructure is considerable, as corrosion damage is disruptive to society and costly to repair. The paper describes a probabilistic and reliability-based approach that predicts the probability of corrosion initiation and damage (severe cracking) for concrete infrastructure subjected to carbonation and chloride-induced corrosion resulting from elevated CO2 levels and temperatures. The atmospheric CO2 concentration and local temperature and relative humidity changes with time over the next 100 years in the Australian cities of Sydney and Darwin are projected based on nine General Circulation Models (GCMs) under (i) high CO2 emission scenario, (ii) medium CO2 emission scenario, and (iii) CO2 emission reduction scenario based on policy intervention. The probabilistic analysis included the uncertainty of CO2 concentration, deterioration processes, material properties, dimensions, and predictive models. It was found that carbonation-induced damage risks can increase by over 400% over a time period to 2100 for some regions in Australia. Damage risks for chloride-induced corrosion increase by no more than 15% over the same time period due to temperature increase, but without consideration of ocean acidity change in marine exposure. Corrosion loss of reinforcement is not significant. The results were most sensitive to increases in atmospheric CO2. [Copyright &y& Elsevier]

• Hurricane wave-induced force and overturning moment on deck are investigated. • A new component-level overturning failure mode of bridge is proposed. • 3D numerical analysis and laboratory experiment are conducted. • Limit states are defined based on deck and bearing performance. • Long-term reliability and risk analyses are performed considering climate change. This paper proposes a comprehensive framework for performance and reliability analyses of coastal bridges under hurricane surge and waves, including a three-dimensional (3D) Computational Fluid Dynamics (CFD) model to simulate the wave-structure interaction, laboratory experiments to improve the model accuracy, a 3D Finite Element Model (FEM) to evaluate bridge and component responses, surrogate models for performance prediction, as well as effects of uncertainties and climate changes in long-term vulnerability analyses. The experimental validation ensures the credibility of the established model and computational results. For accurate and efficient quantification of the structural responses under different surge and wave conditions, surrogate models are introduced for the investigated scenarios, which could not be well predicted by using existing methods. Based on the detailed 3D CFD and FEM results, a new component-level overturning failure mode of a bridge subjected to the hurricane is developed by considering wave forces, overturning moments, bearing damages, and uncertainties in structural and hazard parameters. Given fragility surface and potential changing climate scenario, long-term reliability analysis is performed. The established framework could be accurately and widely applied to other bridges and hurricane scenarios by adjusting the model and experimental parameters. This study could help in exploring the resistance of coastal bridges against natural hazards, and in developing specifications to mitigate future hurricane risk. [ABSTRACT FROM AUTHOR]