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One particular challenge in constructing geotextile tubes is ensuring proper alignment and leveling, especially when connecting them in a series. This study introduces a novel connection configuration to address this challenge by inserting an auxiliary tube between two main tubes. The proposed connection method offers the advantage of consolidating individual geotextile tubes into a unified structure while maintaining a consistent horizontal level. The proposed connection technique was successfully applied both at test site and on dry construction platform for bridge construction. This study is beneficial for practicing engineers as it presents a new and effective method for connecting geotextile tubes, offering valuable insights into its practical application. • A novel, robust, and easily implementable method for connecting geotextile tubes is proposed. • The proposed connection ensures the cohesive formation of individual geotextile tubes into a unified structure and maintains the vertical profile levels. • Successful application demonstrated in a test site. • Application extended to a temporary platform for bridge construction in a real-world case study. • Its availability to the engineering community makes it adoptable, serving as a foundation for future improvements in geotextile connections. [ABSTRACT FROM AUTHOR]

This paper presents experimental and numerical investigations of the seismic performance of a novel self-centering (SC) hollow-core (HC) fiber-reinforced polymer (FRP)-concrete-steel (SC-HC-FCS) bridge column. This new structure is fabricated by mounting external energy dissipators (ED) and applying unbonded post-tensioned (PT) basalt FRP (BFRP) tendon to the conventional HC-FCS column that consists of an outer FRP tube and an inner steel tube, with the space between filled with concrete. The SC-HC-FCS column combines the advantages of accelerated bridge construction and self-centering. The effects of the initial prestress force values and the configuration of the energy-dissipated aluminum bar on the column performance are studied. Based on the experimental and numerical results, it is found that the proposed SC-HC-FCS column shows adequate self-centering and energy dissipation capacities. However, it is required to properly select the configuration and material properties of the aluminum bar as energy dissipators to further refine the seismic resistance of the SC-HC-FCS column. [ABSTRACT FROM AUTHOR]

High temperatures during summer pavement construction can lead to rapid drying, adversely affecting the workability and homogeneity of concrete mixtures, often resulting in quality issues such as cracks and surface defects. This study aims to overcome these challenges by introducing latex modified concrete (LMC) as a solution for enhancing the quality of summer pavement construction. Latex, known for its excellent flexibility and physical properties, is employed to improve the workability and strength of concrete. The study focuses on enhancing the workability and performance of latex in bridge construction within LMC during the summer. The effects of nonionic emulsifier type, alkyl ethylene oxide (AEO) and alkyl phenyl ethylene oxide (APEO), were investigated. In latex, the AEOs with alkyl chains containing 9–13 carbons and 20–40 ethylene oxide units exhibited remarkable workability in LMC. To improve workability even more, the addition of 0.5 wt% superplasticizer per unit of cement was found to be effective. This research contributes to the field by demonstrating the efficacy of nonionic emulsifiers and superplasticizers in latex in enhancing summer workability and their effects on the compressive strength of concrete. [Display omitted] • Enhances LMC workability in hot, humid conditions with strategic additives. • Develops an innovative latex formula to enhance LMC for rapid summer drying. • Uses AEO/APEO emulsifiers to boost LMC miscibility and workability for pavement construction. • Increases in LMC's compressive strength, enhancing durability and performance in extreme climates. [ABSTRACT FROM AUTHOR]

Advancing the Qiongzhou Strait Sea-crossing Bridge program is crucial for regional integration and economic development, yet the intricate coupling effects between environmental variables and structures pose significant challenges to bridge construction. Therefore, it is essential to thoroughly explore the harsh environmental characteristics and dynamic responses of the bridge. This study aims to establish a comprehensive framework for stochastic dynamic analyses of sea-crossing bridges, considering the combined impact of diverse environmental factors. Historical typhoon data is utilized to hindcast typhoon waves, forming a joint probabilistic model for wind and waves. Multivariate environmental contours are then created to assess wind and wave features for various alignments of the Qiongzhou Strait Sea-crossing Bridge. Using a finite element model, the dynamic response of the bridge is examined under varied sea conditions. The integration of the peak-over-threshold (POT) method with Copula theory enhances the examination of wind and wave characteristics, leading to more accurate representation of the joint probabilistic models. By employing the ADCIRC + SWAN model for typhoon wave analysis, this research provides valuable insights into assessing wind and wave characteristics, favoring the Generalized Pareto (GP) distribution and recommending the Western Route as the optimal choice for bridge construction. Furthermore, a new index known as the significant displacement is proposed, which can mitigate stochastic process variability and improve precision in describing structural responses under extreme environmental conditions. This study offers valuable insights into the practical aspects of designing sea-crossing bridges exposed to complex marine environments. • The proposed Copula-based method can enhance the goodness of fit of the joint probabilistic model. • A general framework is established for conducting dynamic analyses of sea-crossing bridges under joint wind-wave actions. • The results provide valuable insights for the design of sea-crossing bridges. [ABSTRACT FROM AUTHOR]

• Presents a self-developed framework for vehicle–bridge interaction simulation. • Validated using a laboratory experiment and an earlier numerical case. • Specialized for large vehicle–bridge systems and decks with slopes and curves. • Proposes a vehicle library input criteria that unifies all existing road vehicles. • Reveals new phenomena of large viaduct systems under asynchronous seismic excitation. The coupled motion between bridges and vehicles is known as vehicle–bridge interaction (VBI). It is crucial for bridge design, monitoring, and vehicle safety and comfort. VBI studies typically rely on general-purpose finite element (FE) software. Although precise, they are not optimized for simulating large-scale bridges with numerous vehicles, which can result in long processing times and modeling challenges. This paper presents a self-developed framework in MATLAB™ for large-scale VBI simulation. The framework divides the simulation task into five modules and supports asynchronous seismic excitation (ASE), handles different deck geometries, unifies all road vehicle models and inputs with a vehicle library, supports variable vehicle velocity (VVV) and different traffic scenarios, and handles wheel–deck detachment. All functions have been designed with easily accessible interfaces to facilitate secondary development. The framework was verified using a 2D sprung mass benchmark case compared to a closed-form solution, and a 3D simplified model compared to commercial FE software. It was also validated through a laboratory experiment. Further demonstrations of a large-scale VBI system highlighted new phenomena and emphasized the significance of considering the ASE effect in similar systems. With ongoing improvements, the framework has the potential to become a practical tool for VBI simulation. [ABSTRACT FROM AUTHOR]

A series of numerical simulations were completed to investigate the behavior of intact, fire-damaged, and Carbon Fiber-Reinforced Polymers (CFRP) retrofitted reinforced concrete (RC) bridge columns of varying sizes subjected to vehicle collisions. Three-dimensional finite element models of isolated RC columns and their foundation systems surrounded by soil volumes were developed using LS-DYNA. A comprehensive parametric study was carried out to investigate the effects of nine demand and design parameters on the performance of bridge columns. Studied parameters included: column diameter, column height, unconfined compressive strength, steel reinforcement ratio, fire duration, CFRP wrap thickness, wrapping configuration, vehicle's mass, and vehicle's speed. For each studied scenario, Peak Twenty-five Milli-second Moving Average (PTMSA) was employed to estimate the Equivalent Static Force (ESF) corresponding to each vehicle collision scenario. Resulting ESF s were then utilized to assess effectiveness of the current ESF approach available in the American Association of State Highway and Transportation Officials Load and Resistance Factor Design (AASHTO-LRFD) Bridge Design Specification for analyzing and helping design bridge columns under vehicle collision. Multivariate nonlinear regression analyses were used to derive an empirically based, simplified equation to predict the ESF that corresponds to a vehicle collision. Rather than constant design force, this equation established a correlation between ESF and kinetic energy, column axial capacity, and column height. Results indicated that the proposed equation is reliable and can accurately predict ESF s over a diverse range of collision scenarios that included intact, fire damaged, and CFRP retrofitted columns. To facilitate realistic implementation of the derived equation, an ESF assessment framework was also devised. • Performance assessment and insights on intact, fire-damaged, and CFRP retrofitted bridge pier columns under vehicle impact. • Developed 3D finite element models of isolated bridge column, foundation system, and surrounding soil domain using LS-DYNA. • Conducted a comprehensive parametric study including nine demand and design variables. • Derived an empirically based, simplified equation that predicts ESF over a wide range of vehicle collision scenarios. • Proposed an assessment framework to facilitate the implementation of the proposed equation. [ABSTRACT FROM AUTHOR]

This study proposes a motion-compensation vision measurement method and system for structural displacement, termed the parallel camera network (PCN). Based on the fixedly connected calibration cameras and measurement cameras, the PCN method effectively address the optical measurement problems of the unstable observation platform. Unlike existing ego-motion compensation methods, the PCN method allows for reference or stationary points that are distant from the camera stations, significantly reducing motion-induced measurement errors of the observation platform. Laboratory tests showed that compensating for platform motion tripled measurement accuracy using the PCN method. In practical applications, the system has been successfully deployed for monitoring subsidence of operational high-speed rail piers and the arch axis during large-span arch bridge construction. The proposed method and system significantly enhance the engineering flexibility of visual measurements. • A new vision measurement system for structural displacement is proposed. • The camera-motion-induced measurement error can be well compensated. • Successful field applications of the bridges during the construction. • Widely expanding the engineering adaptability of visual measurement. [ABSTRACT FROM AUTHOR]

• Statistics of ship and bridge collision accident. • Active collision avoidance technologies of bridge against ship. • Passive anti-collision protective technologies of bridge against ship. • Typical applications of bridge anti-collision against ship. The collisions between bridges and ships might cause severe damage to both of them, which is impossible to avoid completely, although several specifications or requirements need to be followed in the design of bridges and during the navigation of ships passing bridge. Many researches on protective technology had been conducted to reduce the potentially disastrous consequences. These technologies can be broadly categorized into two main types: the technologies of collision avoidance, which try to reduce the collision possibility by warning the passing ship that might impact the bridge; and passive collision protections, which use protective structures to minimize the damage of bridge and ship due to impact. The purpose of the present paper is to systematically summarize both classifications and then provide insights into their characteristics, advantages, disadvantages, and suitable conditions for application. Additionally, the related approaches originally designed for other applications but with potential relevance are also discussed, such as ship-ship collision avoidance. This review can serve as meaningful guidance and reference for future research and realistic engineering applications. [ABSTRACT FROM AUTHOR]

The high strength concrete has been extensively used in the past decades for several construction projects such as high-rise buildings, bridge construction, sports arenas etc. The prominent difference between strength concrete (HSC) and conventional concrete is the lower water-to-binder ratio, which imparts an overall better strength and durability to the concrete. However, certain undesirable characteristics, such as high shrinkage, high hydration heat, and early age cracking, can also be found in such concrete and therefore, require special consideration. The curing of high strength concrete therefore becomes an utmost important factor to minimise the effect of the aforementioned problems. This review article aims to outline the outcomes of various curing techniques and establish a systematic framework for evaluating their effect on high strength concrete. The curing methods for high strength concrete presented in the study include steam curing, oven curing, autoclave curing, dry curing, burlap curing, high and low temperature curing, vacuum curing and internal curing. The performance of the concrete depends on several factors and quantifying them simultaneously may not be feasible; however, summarising one of the major factors, i.e., curing, would provide valuable addition to the overall discussion. • A detailed review of various curing techniques employed for high strength concrete is presented. • Merits and demerits of different curing methods are compared. • Effect of curing methods on strength and durability of high strength concrete are compared. • Proposed mathematical models for internal curing are discussed. [ABSTRACT FROM AUTHOR]

To study the bending behavior of high-strength steel (HSS)-precast reinforced concrete (PRC) slab composite beams with clustered studs under hogging moment, five prefabricated composite beams were tested under single-point loading. The key parameters are shear connection degree, shear pocket spacing in the PRC slab, and applying precompression to the concrete or not. The results showed that two failure modes appeared in the composite beam, including flexural failure and shear failure. The composite beams made of Q550 steel and C50 concrete have full composite action and good overall bending behavior. In addition, applying the prestressing force in the PRC slab can effectively increase the cracking load of the slab and slightly improve the bending behavior. When the shear pocket spacing is increased from 360 mm to 800 mm (the limit value in the AASHTO LRFD Bridge Design Specifications is 610 mm), the composite beam can still maintain the full composite action. The existing specifications can be used to predict the bending capacity and stiffness of the HSS-PRC slab composite beam under hogging moment, the result is relatively conservative for the former but is consistent for the latter. • Single-point loading tests on the HSS-PRC slab composite beams. • HSS composite beams have good bending behavior under hogging moment. • Prestressing in PRC slab is effective in improving the anti-cracking behavior. • Evaluating the rationality of enlarging the shear pocket spacing. • Existing codes are conservative in bending capacity but accurate in stiffness. [ABSTRACT FROM AUTHOR]

This article focuses on multiobjective optimization in the design of bridges and viaducts. The problem is characterized as a multi-objective optimization, with the objective functions being the construction cost, the environmental impact (CO 2 emissions) and the design service life. For optimization, three commonly used metaheuristics in structural optimization problems were tested: Multiple Objective Particle Swarm Optimization (MOPSO), Nondominated Sorting Genetic Algorithm II (NSGA-II) and Strength Pareto Evolutionary Algorithm 2 (SPEA2). The results showed that MOPSO outperformed the other methods, achieving the highest hypervolume and Pure Diversity values. Once the best performing metaheuristic was defined, the calibration of the MOPSO parameters was then developed to improve the quality of the solutions found, reduce the execution time and increase the robustness of the algorithm. Using the Taguchi method with an orthogonal matrix consisting of 54 experiments, five parameters were evaluated at three different levels, totaling 270 analyses. The results indicated that parameter calibration led to an increase in the average hypervolume compared to the results before calibration. Moreover, the coverage of two sets revealed the superior performance of the calibrated set, demonstrating better trade-offs among the objective functions. • Optimization of bridge and viaduct design are reviewed. • Comparing MOPSO, NSGA-II, SPEA2 for real-world viaduct design. • Calibrated MOPSO yields improved trade-off solutions for real-world viaduct design. [ABSTRACT FROM AUTHOR]

In previous simulations of train–bridge interaction systems (TBIS), the supporting system for the train are commonly treated as beam structures, leading to less accurate results, particularly for small-span cases. To address this limitation, a modified vertical TBIS is proposed. In the presented TBIS, the supporting system is considered as a Reissner–Mindlin plate, and the displacement field is described by first-order shear deformation theory (FSDT). To establish the model, radial point interpolation method (RPIM), a meshless method, is employed. Finally, a coupled dynamic equation is established to calculate various responses of the system. Several numerical examples are presented to illustrate the disparities between the system based on plate model and traditional beam model. The results indicate that the beam model yields higher estimates of the mid-span vertical displacement of the bridge, while the peak of the mid-span vertical acceleration is smaller compared to the plate model; additionally, it is observed that the carbody is primarily influenced by rail irregularities. Consequently, the proposed plate model offers distinct advantages over the beam model in providing comprehensive structural response information, thereby offering novel insights into bridge design and analysis. Additionally, this marks the inaugural application of the meshless method in the field of TBIS, which further extends the application scope of meshless methods. • A new train–bridge interaction system (TBIS) is proposed. • The FSDT-RPIM modeling approach is first used in the field of TBIS. • The proposed TBIS is more competitive than the traditional system. • The feasibility of further improving the box girder model in TBIS is verified. [ABSTRACT FROM AUTHOR]

In the background of the high demand for accelerated bridge construction (ABC), more detailed research is still needed on the connection method of prefabricated columns in high-intensity areas to facilitate on-site construction and reduce costs. Therefore, this study proposed a shallow socket connection method suitable for column-footing joints and the Ultra High-Performance Concrete (UHPC) is filled with the gap between the column and footing. A shallow socket connection column and a shallow socket-corrugated pipe hybrid connection column were constructed with a socket depth of 0.6 times the column diameter, and a quasi-static test was conducted to investigate their seismic capability. As a comparison specimen, a cast-in-place (CIP) specimen was also tested, and the scale ratio of all specimens is 1:2. Finally, to predict the damage mode and capacity of the shallow socket column, a simplified strut-and-tie model was developed through mechanical analysis. The proposed shallow socket-corrugated pipe hybrid connection column has the seismic performance not weaker than that of the CIP column and shallow socket connection column, and even performs slightly better in terms of energy dissipation capacity, making it more suitable for moderate and high-intensity areas based on experimental results. The established model of the socket joints could reflect the force characteristics of the shallow socket column and calculate the lateral forces of the column under different damage conditions to determine the modes of failure. • A shallow socket-corrugated pipe hybrid connection was proposed used for the precast column joints. • A mechanical model was developed to calculate the length of the stress distribution in the socket part. • A simplified strut-and-tie model was developed to predict the damage mode of the socket column. [ABSTRACT FROM AUTHOR]

Assessing the seismic capacity of pier columns is a crucial element in the performance-based seismic design of bridges. Such assessment necessitates a probabilistic approach to accurately determine the marginal probability distributions of seismic capacities and to characterize the dependencies among these variables. In response to this need, this paper employs Multi-Output Gaussian Process Regression (MO-GPR), a probabilistic machine learning method, to jointly model the multiple seismic capacities of pier columns. We initially introduce a probabilistic seismic capacity model that utilizes MO-GPR for pier columns and validate its predictive accuracy in comparison to Bayesian linear regression and existing empirical methods. Subsequently, the methodology is augmented by the integration of hierarchical modeling within the MO-GPR framework, resulting in a Multi-Output Hierarchical Gaussian Process Regression (MO-HGPR) model that effectively estimates intraclass correlation coefficients for specific types of datasets. It is postulated that these correlation coefficients also reflect correlations associated with multiple components of the real structure. This study employs MO-HGPR and MO-GPR separately to investigate the potential correlations of seismic capacities among pier columns and distinct limit states. The results demonstrate that the MO-GPR model exhibits superior prediction accuracy and more effectively portrays uncertainty compared to existing empirical models. Moreover, the correlations of seismic capacities among piers and limit states are both robust and significantly impact the seismic fragility of bridges. This finding highlights the essential nature of considering capacities correlations in seismic fragility or risk assessment processes. • Probabilistic prediction of seismic capacity of piers via Gaussian process regression. • Proposed a Hierarchical Gaussian Process Regression model with random effects. • Characterizing the seismic capacities correlations among piers and limit states. • These correlations exert a significant impact on the seismic fragility of a bridge. [ABSTRACT FROM AUTHOR]

Precast concrete bridge bents are good candidates for accelerating bridge construction. In seismic regions, in addition to construction speed, there is a need to improve seismic performance of bridges. One promising solution is self-centering bridge bents that use post-tensioning and external energy-dissipation devices as a hybrid system. This paper presents cyclic load experiments of hybrid two-column bridge bents to assess their performance regarding self-centering and hysteretic energy dissipation. The cyclic experiments were conducted on 42% scaled bridge bents that used unbonded post-tensioning (PT) bars for self-centering and stretch length anchors (SLAs) as external energy dissipators. A total of six experiments are investigated: three with PT bars and SLAs and three with PT bars only. The variables included the number of PT bars in each column (two or four), the initial post-tensioning force in the columns, and the shear key details in the footings and cap beam. The PT bars remained elastic until 4.0% drift ratio but some variation was observed in the post-tensioning forces especially for columns with two PT bars. For post-tensioned bridge bents with or without SLAs, increasing the number of PT bars in each column from two to four enabled efficient self-centering by limiting the residual drift ratio to 0.5%. There was no damage to the concrete for bents with four PT bars and there was repairable concrete damage for bents with two PT bars. The hysteretic energy dissipated by bridge bents with SLAs in addition to PT bars was 1.8 to 3.2 times the hysteretic energy of bridge bents with only PT bars. • Cyclic experiments of bridge bents: three with post-tensioning (PT) bars and three with stretch length anchors (SLAs) and PT bars. • For post-tensioned bridge bents with or without SLA the PT bars remained elastic until 4.0% drift ratio. • Increasing the number of PT bars per column from two to four resulted in residual drift below 0.5%. • Hysteretic energy dissipated by bridge bents with PT bars and SLA was 1.8 to 3.2 times that of bridge bents with PT bars only. [ABSTRACT FROM AUTHOR]

To study the bending behavior of high-strength steel (HSS)-precast reinforced concrete (PRC) slab composite beams with grouped demountable bolts under hogging moment, single-point loading tests were carried out to evaluate the bending behavior of the five prefabricated composite beams, and the key parameters are shear connection degree, shear pocket spacing in the PRC slab, and applying precompression to the concrete or not. The test results indicate that the HSS composite beams have good overall bending behavior, and two failure modes are recorded including the flexural failure, and the concrete damage in the shear pocket region. The prestressing force can effectively increase the anti-cracking performance of the slab and slightly improve the bending behavior, while increasing the shear connection degree from 1.80 to 3.61 or the shear pocket spacing from 360 mm to 800 mm (the limit value in the AASHTO LRFD Bridge Design Specifications is 610 mm) under the same shear connection degree has a limited influence on the bending behavior, and the composite beams still have the effective composite action. The existing formulas are conservative in calculating the bending capacity of HSS composite beams but have a high degree of consistency in stiffness. • Hogging moment beam tests of HSS-PRC slab composite beams. • Grouped demountable bolts are employed as the shear connectors. • Prestressing in PRC slab is effective to improve the anti-cracking behavior. • Rationality evaluation on enlarging the shear pocket spacing. • Existing codes are conservative in bending capacity but accurate in stiffness. [ABSTRACT FROM AUTHOR]

In this paper, the dynamic behavior of four railway bridges with integrated retaining walls, considering the effect of soil–structure interaction (SSI), is investigated both numerically and experimentally. Among these bridges, two are single-span, and the remaining two are three-span. Each bridge is equipped with numerous accelerometers and is excited by a hydraulic actuator across various frequencies. Full 3D solid Finite Element (FE) models incorporating the railway bridges and surrounding soils are developed and calibrated using the Frequency Response Functions (FRFs) from each accelerometer. Furthermore, simplified 3D solid and 2D beam models are created for each railway bridge, incorporating springs and dashpots to account for the effect of surrounding soils. The values for these springs and dashpots are obtained from simple equations, except for the impact of the backfill soil in the simplified 2D beam models, which are derived from the impedance functions of the soil medium. The performance of these simplified models is then compared to the calibrated 3D models in terms of modal properties of the first bending mode and the maximum acceleration response during high-speed train passages. The results indicate that the simplified models closely align with the calibrated models in terms of modal properties and high-speed train passage response and can be used as simple and efficient alternatives for practical usage in bridge design. • Experimental analysis of four railway bridges using a hydraulic actuator. • 3D model calibration of each railway bridge and the surrounding soils using forced vibration experiments. • Simplified 3D and 2D modeling techniques of railway bridges, including the SSI, using springs and dashpots. • High-speed train passage analysis of different modeling alternatives. [ABSTRACT FROM AUTHOR]

A mathematical model is proposed for estimating the wind loads caused by the passage of a downburst through horizontal structures, such as bridge decks. The model simulates the three-dimensional flow fields of stationary and environmentally-driven downbursts. It is based on radial and vertical shaping functions of the velocity components, following a path developed for aircraft structures. The radial shaping function of the horizontal velocity is defined with attention to reproducing the local increase in velocity observed in the average field measurements. In addition, the coefficients of an existing empirical vertical shaping function of the horizontal velocity are re-calibrated to better fit the available field data. The shaping functions of the vertical components are derived by imposing mass conservation. The model allows for predicting the large angles of attack on the decks during the passage of downbursts with small to medium diameters. The occurrence of such large angles of attack also implies a change in the aerodynamic design procedure of bridge decks, for which wind tunnel tests are commonly conducted only for angles of attack in the range of about ± 10 °. The aerodynamic coefficients of a NACA profile and a pseudo-rectangular section are used due to the absence in the literature of aerodynamic coefficients of bridge decks for very large angles of attack. Several runs are conducted by varying the downburst properties and the deck height above the ground to provide results useful for the aerodynamic design of bridges. The results confirm the key role played by the vertical component of the velocity in developing the wind loads on the decks during the passage of a downburst. Non-negligible wind loads are obtained, which are not predictable with the existing approaches. The need for conducting dynamic analyses of flexible bridges is also emerging. • A model is proposed for estimating the downburst wind loads on bridge decks • A new radial shaping function of the horizontal velocity has been developed • The large angles of attack imply a change in the aerodynamic assessment of bridges • The results confirm the key role played by the vertical component of the velocity • Non-negligible wind loads are obtained, not predictable with the existing approaches [ABSTRACT FROM AUTHOR]

In recent years, magnetic-responsive soft materials with high remanent magnetization have received significant attention due to their capacity for untethered and rapid actuation under magnetic fields, with diverse applications spanning robotics, biomedicine, and vibration mitigation. Most designs of the magnetic soft materials rely on discrete remanent magnetization orientations, which could limit the actuation performance because of the restricted selection of magnetization orientations and potentially cause fabrication challenges due to the sharp changes in magnetization orientations at the interfaces that may induce strong repelling forces. To expand the programmability and improve the fabricability of the magnetic soft materials, we enable design capability with optimal continuous magnetization orientations. This paper proposes a multiphysics topology optimization framework that concurrently optimizes topologies and continuous remanent magnetization distributions in the magnetic soft materials and structures. Employing the proposed approach, we design and investigate problems of letter programming, actuators, and metamaterials with magnetic actuation under large deformations. We demonstrate that the proposed strategy enhances design flexibility, improves performance, eliminates sharp changes in magnetization orientations, and is capable of creating non-intuitive designs that can achieve multiple functionalities. Finally, we prototype our optimized design to highlight its potential to bridge design optimization and direct-ink-writing fabrication of magnetic materials with continuously varying magnetization orientations. • Multiphysics topology optimization of magnetic soft materials under large deformation. • Simultaneous optimization for geometry and continuous magnetization orientations. • Arbitrary choice and smooth transition for remanent magnetization orientations. • Creating non-intuitive designs achieving multiple functionalities. • Experimental demonstration for direct-ink-writing printed samples. [ABSTRACT FROM AUTHOR]

• Histological and transverse section studies have revealed the three crucial biological steps of graft union formation in durians after grafting. • Changes in phytohormones, phenolic compounds, and TNC levels correlate with graft external symptoms and durian growth post-grafting. • Graft external symptoms have been identified as a potential marker for selecting the most suitable rootstock for durian grafts. • Levels of IAA, zeatin, GA3, ABA, phenolic compounds, and TNC are potential markers for predicting the compatible behavior of durians after grafting. Despite being primarily utilized for the commercial propagation of durian seedlings, there still needs to be more understanding regarding the histological and biochemical changes that durian plants undergo during compatibility. Further research is required to elucidate this aspect of durian plant biology. The investigation utilized the cleft-grafted 'Monthong' durian cultivar onto indigenous durian rootstock. Examining histological and transverse sections elucidated the three fundamental biological processes involved in graft union formation: scion-rootstock adhesion and wound response, callus bridge construction, and vascular reconnection essential for effective wound healing. These changes are related to the appearance of successfully grafted durian with new sprouting, smooth graft union, and dark green leaves. Quantification of endogenous hormones through LC-MS analysis during the process of graft union formation revealed distinct levels of auxins (IAA), cytokinins (zeatin), gibberellins (GA 3), and abscisic acid (ABA) at various stages of graft development post-grafting. Low levels of IAA were observed during the wound response, callus cell formation, and callus differentiation. It was accompanied by significantly higher concentrations of zeatin, which were present at all stages, with particularly pronounced levels during callus bridge formation and vascular reconnection. Upon completion of the union formation, the highest levels of IAA, zeatin, and GA 3 were observed simultaneously with the emergence of a new sprout in the graft, coinciding with the whole connection of the new vascular cambium between the scion and rootstock. After the grafting, ABA appeared only three days later, at the time of the wound response. The phenolic compounds in the durian graft union decreased gradually after the vascular cambium of the scion and rootstock had become fully connected, following the callus formation and proliferation period. Total non-structural carbohydrates (TNC) levels at the graft union area peaked during the initial wound response phase and gradually declined as callus bridge formation and wound healing progressed. TNC increased during vascular cambium formation and decreased when the graft produced new sprouts. The anatomical and visual characteristics, endogenous hormones, phenolic acid, and TNC were influential in the modulation of graft union formation and the early growth of the 'Monthong' durian cleft graft on the indigenous rootstock. These parameters show the potential markers detected since the early nursery stage of durian graft. [ABSTRACT FROM AUTHOR]

In this paper, strength reduction factors (R-factors) for performance-based seismic design of bridges in far-fault seismic regions are developed. Response spectrum analyses (RSA) and nonlinear time history analyses (NTHA) of simplified bridge models with piers of circular and rectangular sections having several substructure-superstructure connections are performed for wide ranges of design parameters and pier displacement ductilities based on target performance levels are obtained. Subsequently, a set of equations representing R-factors is proposed by performing linear regression analyses on the data obtained from the analyses. The accuracy of the proposed equations is investigated by performing error performance analyses, which indicated R-factors with mean error values close to zero. Furthermore, a simple application procedure of the proposed R-factor equations is presented and explained in detail through various sample bridges designed to achieve the performance objectives recommended by AASHTO LRFD, Eurocode, and the Canadian Highway Bridge Design Code (CSA). Eventually, a comparison between the estimated R-factors and those suggested by design codes is presented. The results showed that AASHTO LRFD recommends conservative R values for single-column bents, while it provides overestimated R values for multiple-column bents. Indeed, it is found that Eurocode recommends conservative R values for piers of limited-ductile behavior and relatively high R values for piers of ductile behavior. Therefore, it is concluded that the R-factors suggested by design codes might result in performance levels not intended in design. • Strength reduction factors (R-factors) for performance-based seismic design of RC bridges is presented. • The paper presents Six R-factor equations expressed in terms of various design parameters. • A novel performance-based seismic design procedure for RC bridges is introduced. • The paper provides an assessment of the R-factors existing in design codes by comparing them with the estimated ones. • The research provide valuable information to the bridge engineering community for improving the seismic design codes. [ABSTRACT FROM AUTHOR]

In accelerated bridge construction (ABC), precast segmental piers (PSPs) have shown significant progress in shortening the construction period and reducing the cost. By combining multiple segments with post-tensioned (PT) tendons, the desired self-centering ability can be introduced; however, this may lead to a lower energy dissipation (ED) capacity and concentrated damage. To address this concern, the present study proposes a design concept that promotes multiple joint openings to achieve a better energy dissipation capacity and decentralized damage without compromising the self-centering ability. Two main approaches for this objective are discussed in detail. The first approach incorporates different arrangements of ED rebars at various joints, while the second introduces innovative damage control rubber joints (DCRJs) with varying stiffness beneath each segment. Four scaled specimens designed using these two approaches were quasi-statically tested. The observed damage, final failure mode, energy dissipation capacity, resilience index, and damage decentralization were further examined. The results revealed that for PSPs designed using the first approach, the joint openings were successfully decentralized only up to a certain level, after which they were still predominantly concentrated at a single joint, leading to strength degradation and damage concentration. PSPs designed using the second approach demonstrated decentralized joint openings, improved displacement ductility, and damage mitigation, resulting in both superior seismic and post-seismic performance. • A concept involving multiple joint openings for the seismic design of post-tensioned precast segmental piers was proposed. • A precast segmental pier with a different arrangement of ED rebars was designed and tested. • Two precast segmental piers with innovative damage control rubber joints were designed and tested. • The seismic performance of the precast segmental specimen with different arrangement was investigated. [ABSTRACT FROM AUTHOR]

The ever-increasing demand for accelerated construction of urban bridges or viaducts calls for more prefabrication with various joint schemes, while satisfying the need for seismic resilience. On the other hand, segmentation into components of various shapes and morphologies is common for multifunctional structures found in living organisms and ancient Chinese timber structures, which also inspires the development of resilient segmental bridge column design. To provide further insights into the cost-effective resilient design of precast bridge columns, this paper suggests the use of resettable sliding joints (RSJ) comprising lubricated gently-inclined joint interface with partially debonded tendon arrangement, essentially forming a hybrid sliding and rocking seismic isolation system of precast segmental structures. The deformability of the proposed design is high. Similitude analysis was conducted considering the rigid body behavior of individual segments under seismic input. It presents the conceptual shaking table testing of four 1:12 prestressed segmental column models fabricated with special three-dimensional (3D) printed plastic molds and interface treatment. A motion capture system was installed for accurate 3D displacement data acquisition and five typical major near-fault earthquake records were selected. Among all specimens, the RSJ segmental column could reach a high damping ratio of about 20 % during the tests, and it outperformed the others in many aspects: (i) a tolerable maximum top drift of about 1 %; (ii) a moderate percentage of transient rocking of about 20 %; (iii) an evenly distributed sliding displacement among all sliding joints; and (iv) negligible residual sliding drift at sliding joints. These superior attributes of RSJ segmental column are consistent under excitation of consecutive rounds of different major earthquake records, indicating high robustness as well as high seismic resilience in the design of RSJ segmental columns. • Proposed segmental column design is inspired from ancient Chinese timber Pagoda. • Rigid body dynamics is decisive to reproduce reliable hybrid sliding & rocking behavior in scale-down shaking table test. • Enhanced interaction from partially debonded tendons can induce multi-layer sliding behavior. • Proposed segmental column is of high robustness & resilience under various major excitations. [ABSTRACT FROM AUTHOR]

Knowledge graphs (KGs) are crucial in documenting bridge maintenance expertise. However, existing KG schemas lack integration of bridge design and practical inspection insights. Meanwhile, traditional methods for node feature initialization, relying on meticulous manual encoding or word embeddings, are inadequate for real-world maintenance textual data. To address these challenges, this paper introduces a bridge maintenance-oriented KG (BMKG) schema and approaches for graph data mining, including node-layer classification and link prediction. These methods leverage large language model (LLM)-based text encoding combined with GraphSAGE, demonstrating excellent performance in semantic enrichment and KG completion on deficient BMKGs. Additionally, ablation studies reveal the superiority of the pre-trained BERT text encoder and the L2 distance pairwise scoring calculator. Furthermore, a practical implementation framework integrating these approaches is developed for routine bridge maintenance, which can facilitate various practical applications, such as maintenance planning, and has the potential to enhance the efficiency of engineers' documentation work. • This paper introduces a hierarchical knowledge graph schema based on real-world bridge maintenance reports. • A node-layer classification approach is proposed for semantic enrichment by employing GraphSAGE and LLM-based text encoding. • A link prediction approach is proposed for graph completion by leveraging GraphSAGE and contrastive learning. • An implementation framework integrating the above schema and approaches is designed for practical bridge maintenance. [ABSTRACT FROM AUTHOR]

The growing demand for buildings and infrastructures requires optimal construction schedules under real-world complexities. This paper presents an automated scheduling optimization method for large construction projects, considering real-world constraints and the need for rescheduling. A Deep Reinforcement Learning (DRL) model with a Valid Action Sampling (VAS) mechanism is proposed to optimize schedules. The method integrates a Graph Convolutional Network (GCN) for feature extraction and includes a reward shaping mechanism to expedite convergence. The proposed method outperforms traditional methods with reduced project duration and runtime in both scheduling and rescheduling cases. This advancement benefits construction managers seeking efficient and flexible project management. The findings inspire future research into broader and more practical construction scheduling solutions utilizing DRL. • This paper considers the precedence and resource constraints in bridge construction and aims to shorten the duration. • Deep reinforcement learning can generate optimal construction schedules without constraint violations. • Proposed valid action sampling mechanism enhances the performance of the reinforcement learning. • Reward shaping is introduced, and it boosts the convergence of the neural network in model training. • Deep reinforcement learning is compared with classic methods and shows better performance in real case studies. [ABSTRACT FROM AUTHOR]

The safety of pier foundations is an important issue in bridge construction, where local bridge scour is a major cause of bridge damage worldwide, exacerbated by ice sheets. This paper offers a live bed scour experimental investigation that assesses the impacts of the new anti-scour device guide pillar of different sizes on geometric properties of scour, downflow velocity distribution, and turbulence intensity around the pier under different flow velocities and roughnesses, and to select the optimum installation position and size of the guide pillar. The results demonstrate that the guide pillar has a considerable effect on the scour hole and downflow around the pier, and the maximum reduction rate of scour depth is 59.3% in the optimal installation position (2 d). By arranging distributed thin-film pressure sensors on the pier and measuring the pressure distribution on the facing water surface of the pier and the position of the center of gravity, this paper analyzes the distribution characteristics of the water flow force on the pier and the impact resistance of the guide pillar to the pier scour. The study found that the guide pillar reduces the water flow force by 61.3% without considering the effect of hydrostatic pressure. • Designed an anti-scouring device with a good anti-punching effect and high stability - guide pillar. • The first attempt to apply thin-film pressure sensors to bridge piers to monitor water flow force. • Thin film pressure sensor has good applicability, and it can be tried to continue to be applied in this field. • The effect of anti-scouring devices on local bridge scour at different flow velocities and different roughness rates was investigated. • The guide pillar has a strong anti-impact ability, and the water flow force can be reduced by 61.3%. [ABSTRACT FROM AUTHOR]

Flood-induced scour is one of the leading causes of bridge failures in the United States, accounting for 53 % of recorded failures between 1989 and 2000. With many existing bridges considered "scour critical", it is essential to closely monitor its development for effective mitigation. However, despite advances in scour hole measurement techniques, continuous monitoring of scour remains underused and little guidance is available to maintenance engineers to assess structural stability from scour depth measurements. This research presents a proof-of-concept, model-free bridge pier structural assessment framework. This framework is built on a library of bridge pier failure surfaces – curves that define failure limits for combinations of scour, wind, and flood loading for a range of structural configurations and site conditions. User input is limited to basic structural and site information, from which a corresponding failure surface is automatically selected, either directly or through interpolation between surfaces in the library. In this study, the creation of a failure surface library and framework is focused on pile bent pier designs, due to their widespread use. A broad scope of parameters was modeled such that common configurations of pier bent bridge designs and site conditions in Florida were considered. Sensitivity studies were performed to identify parameters for which modeling simplifications could be made to build the failure surface library with reduced computational burden. Results from three case study bridges are presented to verify that the resulting assessment framework maintained reasonable representation of structural response. • This research developed a new, model-free assessment framework which uses a library of failure surfaces. • Failure surfaces provide information on the combination of demands which results in failure. • Baseline failure surfaces are generated using simplified finite-element models representative of bridge design practices. • Site-specific failure surface generated from adapting baseline failure surfaces using in-situ soil data. • Results from three case studies demonstrate good agreement between framework-generated and real-bridge failure surfaces. [ABSTRACT FROM AUTHOR]

This study proposes a simplified analysis method that couples the bridge and train-track subsystem in a weak form to facilitate the dynamic analysis of the train-track-bridge coupled system (TTBS) under earthquakes. The method includes three main steps: (i) performing dynamic analysis of the bridge under seismic conditions to obtain the response of the bridge deck; (ii) interpolating the bridge displacement beneath each wheelset based on the train's velocity, departure time, and the initial positions of the wheelsets; and (iii) assessing the running safety of the train by incorporating the interpolated bridge response as track irregularity into the train-track coupled system. Steps (i) and (iii) can be analyzed separately using finite element and multibody dynamics software, eliminating the need to create a complex TTBS model that is challenging to achieve within a single software platform. Additionally, based on the method's assumptions, the earthquake excitation on the train can be separated into the seismic inertial effect and seismic-induced bridge deformation, enabling a quantitative analysis of the impact of these two types of excitations on train safety. Taking a 10-span simply supported bridge and a long-span cable-stayed bridge as examples, the proposed method's assumptions are verified by comparing its results with those obtained from a complex TTBS model. Furthermore, the impact characteristics of inertial effects and seismic-induced bridge deformation on train safety for these two types of bridges are analyzed. The proposed method offers robust support for seismic design of bridges and facilitates a comprehensive analysis of the mechanisms through which seismic excitations affect train safety. • Proposal and validation of a simplified method for running safety evaluation of train on bridges under earthquake excitation. • Separation of seismic excitation on the train into seismic inertial effect and seismic-induced bridge deformation. • Analysis of impact characteristics of inertial effects and seismic-induced bridge deformation on train running safety. [ABSTRACT FROM AUTHOR]

• Local splitting of bridge girders due to prestressing needs to be always addressed. • Strategy of comprehensive analysis of bridge global and local response is proposed. • Efficiency of the Concrete Damage Plasticity law is confirmed. • Importance of local analyzes of post-tensioned bridges is strongly emphasized. The cracking of a post-tensioned T-beam superstructure, which was built using the incremental launching method, is analyzed in the paper. The problem is studied in detail, as specific damage was observed in the form of longitudinal cracks, especially in the mid-height zone of the girder at the interface of two assembly sections. The paper is a case study. A detailed inspection is done and non-destructive testing results of the girders are briefly discussed. The attention is especially focused on advanced and comprehensive numerical simulations of the bridge mechanical behavior. Linear and nonlinear static calculations are performed employing the Finite Element Method at global and local levels of precision, enabling deep insight into the bridge response during all the stages of bridge construction and after it is opened to traffic. The crack propagation process in local analyses is described by the application of the Concrete Damage Plasticity law, the parameters of which were carefully chosen. The predicted damage patterns closely resemble those observed at the site. The results reveal, that the girder damage process was initiated when centric prestressing was applied, because vertical reinforcement of the assembly section front-end surface was not designed. However, the damage did not compromise the safety of the bridge. Finally, the repair methods employed are described and also a discussion is presented on how to prevent the occurrence of such cracking. [ABSTRACT FROM AUTHOR]

This study utilizes the concept complex linear Diophantine fuzzy set (CLDFS) which is an advanced framework for handling ambiguity in the presence of periodicity for decision-making. Unlike existing techniques, CLDFS offers a larger solution space, incorporating reference parameters α and β. Two real-life scenarios – bridge design selection and AI system choice – are examined to showcase CLDFS's impact on practical applications. The study presents multi-attribute decision-making (MADM) and multi-attribute group decision-making (MAGDM) algorithms with visualizations, applied to warehouse distributor selection and faculty candidate evaluation. The comparative analysis highlights CLDFS's advantages over other methods [ABSTRACT FROM AUTHOR]

This paper conducts a comparative study into the hydrodynamic loads and bearing reaction forces between T-deck and box-deck bridges under freak waves. Initially, a high-fidelity numerical flume is established and validated to accurately simulate the freak wave-bridge interaction. Subsequently, a comprehensive analysis distinguishes the hydrodynamic characteristics associated with equivalent-sized freak waves, Stokes fifth-order waves, and solitary waves. Utilizing the developed numerical flume, the detailed comparisons of hydrodynamic loads on T-deck and box-deck bridges under freak waves are conducted, considering various focus locations, wave height to significant wave height ratios (α 2), and wave crest to wave height ratios (α 3). The study then delves into the seaward and landward bearing reactions for both bridge types. Additionally, the ultimate resistance envelope for a tension-compression bearing is explored through a finite element model, and the safety evaluation of the bearings under freak waves is carried out. Key findings reveal that (a) freak waves pose a more significant threat to structures than the other two wave types; (b) strengthening the seaward bearing for the box-deck and the landward bearing for the T-deck is recommended in the bridge design under the impact of freak waves; and (c) the ultimate resistance capacity envelope efficiently evaluates the bearing capacity when encountering freak waves with the working conditions used in this paper. • The force induced by freak wave, Stokes-5th order wave, and solitary wave is compared. • Hydrodynamic distinctions between T-deck and box-deck under freak waves is examined. • The bearing reaction force under varying parameters of freak waves is analyzed. • An ultimate resistance envelope is obtained for a tension-compression bearing. [ABSTRACT FROM AUTHOR]

The paper discusses the critical importance of understanding and managing risks associated with the construction of pre-stressed girder bridges. As a result, it aims to assess, analyze, and propose strategies to mitigate various risk factors contributing to delays and schedule overruns in bridge construction projects. These risk risks through literature review and interviews with stakeholders engaged in bridge projects in Pakistan, highlighting the need for activity-specific risk analysis rather than general assumptions. The findings show that 74% of the identified risks can be effectively managed through suitable risk management strategies. Additionally, it was suggested that 17% of the risks should be transferred, while 9% of the identified risks must be retained without any mitigation measures. This survey not only confirmed risks already identified in existing literature but also brought to light new risks previously unnoticed. Moreover, the results highlighted significant differences in risk severity among various project activities. This underscores the necessity for conducting activity-specific risk analysis instead of depending on generalized assumptions for the entire bridge construction project. Among all bridge construction activities, piling emerged as the most high-risk activity, while girder installation was deemed the least risky. Based on this assessment, a set of guidelines aim to mitigate these risks and serve as a reference for minimizing schedule overruns in bridge construction, providing valuable insights for bridge constructors to effectively manage risks. [ABSTRACT FROM AUTHOR]

Hybrid reinforcement is explored for column-to-footing connections in seismic regions constructed with grouted duct connections as an accelerated bridge construction method. Two 38% scale precast concrete column-to-footing specimens were built; the first column was reinforced with hybrid reinforcement using a combination of mild steel and glass fiber reinforced polymer (GFRP) longitudinal bars, and the second with all-steel longitudinal bars. Double layers of GFRP spirals were used to provide improved concrete confinement for both columns; GFRP spirals exert higher levels of confining pressure on the column concrete core as deformation increases due to their elastic nature compared to steel spirals that yield. An equation was developed for the cross sectional area and pitch of a GFRP spiral to provide the same confining pressure as a steel spiral. The purpose of the cyclic load tests was to show that the column reinforced with hybrid reinforcement could reduce residual displacements using the elastic nature of GFRP bars. Pull-out tests of GFRP bars inside grouted ducts were carried out to determine the minimum embedment depth to achieve GFRP bar tensile strength. The seismic performance of both specimens was examined under quasi-static cyclic loads. The hybrid column reached a drift ratio of 9.0% drift ratio when a GFRP longitudinal bar fractured in compression; the all-steel column reached a drift ratio of 11.0% when two longitudinal steel bars fractured in tension. The elastic nature of the GFRP longitudinal bars provided substantial self-centering ability and reduced the residual displacement of the hybrid column compared to the all-steel column, thus enhancing its seismic resilience. • Pull-out performance of glass fiber reinforced polymer (GFRP) bars inside grouted ducts. • Seismic behavior of columns with hybrid reinforcement using a combination of mild steel and GFRP longitudinal bars. • Comparison of hybrid column with an all-steel longitudinal column. • Use of grouted ducts to enable accelerated bridge construction. [ABSTRACT FROM AUTHOR]

Construction of bridges by the cantilever method needs to consider the accidental release of the formwork traveller (ARFT) in the design phase. Often this phase is a critical situation that current regulations treat as a static analysis amplified by a dynamic factor due to the difficulty in setting up a model able to simulate the complex interaction between the formwork and the structure in the time domain during the accidental release. To overcome the simplistic approach of the regulations and to avoid the complexity of detailed ARFT modelling, in this research the release of the formwork is modelled as a simple force-time function applied to the bridge. This function has an equivalent effect on the structure as the accidental release, and it has been tuned using experimental tests on a 1:100 scale aeroelastic model of the cable-stayed Bioceanic Bridge. To test the applicability of the proposed time-function the Chilina continuous beam Bridge was also analysed. The article shows that the simplified procedure in the regulations can sometimes underestimate and overestimate dynamic amplification and, thus, a methodology is proposed to carry out the specific dynamic calculation that the regulations suggest for those cases where it is necessary. • Experimental tests on the scale model of the cable-stayed bridge. • Comparison with finite element model results. • Evaluation of the dynamic amplification factor in regulations. • Proposal of force functions for the numerical dynamic study. • Comparison of results between kinds of formwork travellers. [ABSTRACT FROM AUTHOR]

Sea-crossing bridge design incorporates both wind and wave loads. Current design methods usually linearly superimpose the effects of wind and waves, which overestimates their impact on sea-crossing bridges and leads to overly conservative structural design. To assist the development of sea-crossing bridges towards deeper waters and larger spans, this study proposes an optimized Hierarchical Archimedean Copulas (HAC) to construct a high-dimensional joint distribution model, as well as draw multidimensional environmental contours. First, invalid HAC structures are identified through the minimal distance obtained by the HAC collapsing process. Secondly, valid HAC structures are combined with different generator types to find the HAC with the optimal fitting performance, and the HAC model is applied to construct conditional environmental contours through direct sampling (DS). The effectiveness of the proposed method is validated using measured wind speed, wind direction, wave height, wave period and wave direction data near a sea-crossing bridge. Results show that HAC can effectively interpret the correlations among multivariable. Compared to the commonly used C-Vine Copula, this proposed method is more accurate and convenient in high-dimensional spaces. The obtained environmental contour surfaces can provide more suitable wind and wave design values than univariate distributions. • An optimized hierarchical Archimedean copula is proposed for deriving design values of the sea-crossing bridge. • The correlations between the five environmental parameters are analyzed via HAC. • Conditional environmental contours under diverse return periods are derived by DS. • The joint distribution and environment contour of circular-circular-linear-linear-linear variables are carefully discussed. [ABSTRACT FROM AUTHOR]

• The collapse mechanisms of a post-tensioned reinforced concrete (RC) truss bridge occurred during its construction has been analyzed. • Several numerical analyses have been carried out in order to reproduce the bridge failure. • Construction stage analysis has been performed in order to reproduce the bridge construction phases. • The results obtained have been compared to the crack patterns observed in the bridge before and after the collapse finding an excellent match. On March 2018 a post-tensioned reinforced concrete (RC) truss bridge, built inside a North American university campus using the Accelerated Bridge Construction (ABC) method, collapsed during the construction phase, while the bars of a diagonal member were being re-tensioned. This process was not part of the scheduled construction phases, but it was decided by the designers after having observed several cracks in the structural nodes. This paper aims to analyse the final design of the bridge useful to determine the hypothetical causes of the collapse. Several numerical analyses have been performed to reproduce the behaviour of the different structural elements during the construction phases. In particular, construction stage analyses have been carried out to obtain the internal actions acting on the structural elements and on the nodes during the different construction steps and in order to analyse in detail the critical phases where the occurrence of the collapse has been hypothesized. The collapse mechanism is identified in the shear failure of a node of the concrete truss during the re-tensioning of a diagonal element. In fact, the reapplication of the post-tension had increased the axial force of the diagonal and consequently the shear action on the node. Moreover, the results obtained have shown that the bridge has never been in safe conditions, mainly because the interface surface of the cold joints had not undergone any type of work and remained smooth. [ABSTRACT FROM AUTHOR]

Ultra-high-performance concrete (UHPC) has been rapidly accepted in accelerating bridge construction attributed to its superior workability and mechanical performance. However, the unavoidable vehicle-induced vibration in construction site may cause the performance degradation of UHPC, and the influencing mechanisms have not been well-documented. In this study, the effects of various vibration parameters (amplitudes, frequencies, and phases) on the macroscopic properties, nano-mechanical properties and microstructure evolution of unhardened UHPC were investigated. Results demonstrated that the microstructural evolution and strength development of UHPC differed at different introduced vibration energy, although the vibration during the hardening process can disperse the unhydrated cement particles, decrease the Ca/Si values and form additional C–S–H gels. The low-energy vibration (low-amplitude vibration and vibration before initial setting) refined the pore structure and optimized the fiber orientation in UHPC, leading to a volume increase of gel nano-pores (<10 nm) and a higher fiber orientation coefficient (η θ). This improvement results in an increase in its compressive and flexural strength by 0.6%–3.8% and 6.8%–24.5%, respectively. In contrast, however, the high-energy vibration (high-amplitude vibration and vibration after initial setting) coarsened the large capillary pores (100–5000 nm) and macro-pores macro-pores (>5000 nm). Furthermore, the interaction (adhesion and friction) between the aggregate and matrix in UHPC was also disrupted under this condition, as confirmed by SEM. This leads to the evolution of interfacial transition zone (ITZ) in UHPC from a dense framework to a framework with microcracks. [ABSTRACT FROM AUTHOR]

Prefabricated structures have garnered attention in bridge construction owing to their advantages in quality control, cost-effectiveness, and ability to save time. However, assembling prefabricated structures often leads to critical errors that are only discovered during the actual assembly on the construction site. These errors arise from the absence of an effective preassembly verification method, compounded by the inherent fabrication deviation of the different suppliers of prefabricated components. To address this challenge, this paper introduces a novel approach involving the integration of the design for manufacturing and assembly (DfMA) principles and parametric building information modeling (BIM) to develop a preassembly analysis system (PAS). The DfMA methodology enables a seamless information exchange throughout the design–fabrication–assembly process and facilitates a comprehensive analysis of the assemblability of prefabricated structures based on design and fabrication deviation data. Data-driven BIM modeling is leveraged to incorporate the DfMA requirements into the BIM model through customized data templates and user-defined parameters. The PAS is validated through a case study focused on a prefabricated bridge, wherein the potential assembly errors of girders and coupling of decks and girders are examined based on the accumulated fabrication deviation of the connection parts, such as shear pockets and shear connectors. The results demonstrate the efficacy of the PAS in identifying and mitigating assembly errors. Ultimately, this study presents a crucial step toward automated assembly-aware fabrication and lays the foundation for the integration of DfMA and parametric BIM, which enables an enhanced information exchange and reduces onsite assembly errors during prefabricated bridge construction. • BIM-based preassembly analysis system for DfMA of prefabricated bridges is developed. • Data-driven BIM is leveraged to incorporate the DfMA requirements into the BIM model through customized data templates. • DfMA-oriented parametric BIM is proposed to integrate domain knowledge from DfMA process into the BIM model. • The potential assembly errors of the full-depth prefabricated deck are determined. • A case study is used to evaluate the proposed method. [ABSTRACT FROM AUTHOR]

Advances in resuscitation following out-of-hospital cardiac arrest (OHCA) provide an opportunity to improve public health. This review reflects on past developments, present status, and future possibilities using the science-education-implementation framework of the Utstein Formula and the clinical framework of the links in the chain of survival. With the discovery of CPR and defibrillation in the mid 20th century, resuscitation developed a scientific construct for progress. Systems of emergency community response provided operational efficiency to treat OHCA. Contemporary resuscitation involves integrated interventions in the chain of survival: early recognition, early CPR, early defibrillation, expert and timely advanced life support and hospital care, and multidimensional rehabilitation. Implementation of scientific advances is especially challenging given the unexpected nature of OHCA, the need for time-sensitive interventions, and the substantial collective of stakeholders involved in the chain of survival. Systematic measurement provides the foundation to evaluate performance and guide implementation initiatives. For many systems, telecommunicator CPR and high-performance CPR by emergency professionals are accessible, near-term programs to improve OHCA outcome. Smart technologies that activate, coordinate, and/or coach community "volunteers" to accelerate early CPR and defibrillation have conceptual promise, though robust implementation has been achieved by only a handful of systems. Longer-term strategies may leverage technology to develop a high-fidelity "life-detector" or engineer and disseminate a specialized consumer defibrillator designed to bridge care until arrival of professional response. [ABSTRACT FROM AUTHOR]

With the advancement of nanochemistry, artificial nanozymes with high catalytic stability, low manufacturing and storage cost, and greater design flexibility over natural enzymes, have emerged as a next-generation nanomedicine. The catalytic activity and selectivity of nanozymes can be readily controlled and optimized by the rational chemical design of nanomaterials. This review summarizes the various chemical approaches to regulate the catalytic activity and selectivity of nanozymes for biomedical applications. We focus on the in-depth correlation between the physicochemical characteristics and catalytic activities of nanozymes from several aspects, including regulating chemical composition, controlling morphology, altering the size, surface modification and self-assembly. Furthermore, the chemically designed nanozymes for various biomedical applications such as biosensing, infectious disease therapy, cancer therapy, neurodegenerative disease therapy and injury therapy, are briefly summarized. Finally, the current challenges and future perspectives of nanozymes are discussed from a chemistry point of view. As a kind of nanomaterials that performs enzyme-like properties, nanozymes perform high catalytic stability, low manufacturing and storage cost, attracting the attention of researchers from various fields. Notably, chemically designed nanozymes with robust catalytic activity, tunable specificity and multi-functionalities are promising for biomedical applications. It's crucial to define the correlation between the physicochemical characteristics and catalytic activities of nanozymes. To help readers understand this rapidly expanding field, in this review, we summarize various chemical approaches that regulate the catalytic activity and selectivity of nanozymes together with the discussion of related mechanisms, followed by the introduction of diverse biomedical applications using these chemically well-designed nanozymes. Hopefully our review will bridge the chemical design and biomedical applications of nanozymes, supporting the extensive research on high-performance nanozymes. [Display omitted] [ABSTRACT FROM AUTHOR]

• Bayesian networks can be used as expert systems for bridge pile resistance. • The optimal Bayesian structure includes 16 causal relationships between 9 variables. • The expert system was validated on an unseen testing sample with 88.32% accuracy. • Bayesian networks offer unique insights on pile capacity for bridge practitioners. Bridges are one of the critical infrastructure systems and play a critical role in supporting the economic development of nations. During the planning, design, and construction phases of bridges, it is important to ensure that the different bridge components satisfy the desired performance for avoiding catastrophic failure. One example is the foundation system with deep driven piles. A crucial consideration when planning, designing, and constructing bridge foundation system is to accurately estimate the pile resistance (i.e., capacity). However, this process constitutes a considerable challenge for bridge managers and engineers due to the uncertainties, subjectivities, and biases involved in providing accurate estimates. In fact, the current design process of bridge pile foundations is still performed in a relatively simple and deterministic manner. Thus, there is still a lack of studies that were conducted to effectively represent the causalities between different variables impacting the bridge pile resistance using objective, data-driven methods rather than subjective, expert-based methods. Therefore, this paper addresses this knowledge gap by proposing a data-driven, knowledge-discovery Bayesian network model as an expert system to (1) identify the key factors impacting the performance of bridge piles through data-driven knowledge discovery; (2) capture the causal (direct and indirect) relationships between the different variables that influence bridge pile resistance, and (3) predict bridge pile resistance in support of decision making in bridge design and construction. Multiple Bayesian network models were developed using two distinct learning paradigms based on a pile dataset with 18 variables and 2,375 data samples from a large bridge project. One paradigm is to run a regular process for learning graphical models using Bayesian structure learning, while the other one is to couple Bayesian networks with bagging ensemble learning. Model validation results showed that the best model learned by bagging ensemble learning paradigm achieves the highest prediction accuracy of 89.78% for predicting bridge pile resistance. Additionally, the developed Bayesian network models identify 8 critical factors affecting bridge pile resistance. These factors are categorized into four groups, including the external applied force on pile head, pile mechanical property (i.e., compressive stresses in bridge piles), hammer property and operation characteristics (e.g., hammer blow count), and pile cap elevation. The observations from this study would assist bridge managers and practitioners in decreasing the uncertainties that impact the estimation of pile capacity, and thus help in balancing cost-effectiveness with good performance. The paper adds to the body of knowledge by providing a great deal of insights related to the factors and causalities influencing the performance of deep bridge foundations to ultimately help in the plan, design, and construction phases of bridges. [ABSTRACT FROM AUTHOR]

The functionality of expansion joints, bearings, and dampers in suspension bridges is directly impacted by the longitudinal movement of the girder ends. The complex longitudinal resistance of the girder significantly influences this movement in railway suspension bridges. This study develops an analytical model of a railway suspension bridge using measured displacement. The model encompasses various longitudinal nonlinear resistances, including girder-rail interaction, bearing friction, and viscous dampers, enabling a detailed analysis of longitudinal motion characteristics and deformation patterns of girder ends under train loads. This study investigates the effects of various longitudinal resistances on the movement of the girder and stress within the connecting components. A novel central buckle design is proposed to reduce the stress amplitude of the central buckles in railway suspension bridges. Results show that the innovative analysis model can accurately assess the longitudinal movement of girder ends in railway suspension bridges, aligning closely with the measured. The girder displays minimal longitudinal movement under train loads, owing to the longitudinal nonlinear resistances. However, there is a significant relative longitudinal displacement between the cable and girder in short hangers, leading to a considerable increase in bending stress and vast stress in the central buckle. Consequently, when studying the longitudinal movement in railway suspension bridges, it is critical to comprehensively analyze the longitudinal displacement of girder ends and the stress across various bridge components. The novel central buckle effectively mitigates excessive stress on the central buckle during train passage and simultaneously alleviates bending stresses of the short hangers. The findings of this study offer invaluable theoretical direction and practical engineering insights for the rational design of railway suspension bridges. • Developed a novel analytical model for railway suspension bridges to precise evaluation of girder ends' movement under train loads. • Revealed minimal girder longitudinal movement due to nonlinear resistances, with notable relative displacement in short hangers. • Proposed a new central buckle design to reduce component stress, providing practical engineering insights for bridge design. [ABSTRACT FROM AUTHOR]

The integration of digital fabrication technology with prestressed segmental column construction offers significant potential for accelerated bridge construction with material-efficient design. This study aims to explore this potential by developing a novel prestressed segmental column system that utilizes permanent 3D printed concrete (3DPC) formwork for column segment fabrication. Prestressing is achieved in the proposed system by using partially bonded iron-based shape memory alloy (Fe-SMA) reinforcement. Large-scale experiments were conducted on two columns under combined gravity and lateral loading to evaluate the seismic performance and feasibility of the proposed system. The ratio of steel to Fe-SMA reinforcement in the column design was the variable considered in this study. The experimental results showed that the columns could withstand lateral drifts of up to 5% without collapse and the permanent 3DPC formwork showed no premature failure or delamination. Furthermore, the columns exhibited self-centering characteristics, maintaining a residual drift of 1% up to a target drift of 4% when the reinforcement ratio of steel to Fe-SMA rebars was 0.3. The results highlight the potential of the proposed prefabrication concept in designing material-efficient and seismically resilient bridge columns with low damage characteristics. • Novel prefabrication concept for segmental bridge columns. • Combination of 3DPC formwork with advanced Fe-SMA-based prestressing. • Proof-of-concept experiments showcase seismic resilience. • Promising potential for accelerated bridge construction. [ABSTRACT FROM AUTHOR]

To achieve sustainability in bridge design, it is critical to ensure both economic viability and low environmental impact. While stainless steel has great mechanical properties and life cycle performance, the material is expensive, which has limited its use in bridges. This research aims at exploring the benefits of using stainless steel corrugated web girders as an alternative to carbon steel flat web girders in composite road bridges. This concept is expected to lower the investment cost, which enables a broader utilization of the good properties offered by stainless steel. A genetic algorithm optimization routine has been developed to produce bridge designs with minimum weight, investment cost, life cycle cost (LCC), or life cycle impact. Multiple parametric studies are conducted using a simply supported reference bridge. The optimal design solutions are compared for two main design alternatives: conventional S355 flat web girders and duplex (EN 1.4162) corrugated web girders. The parametric studies consider the effects of different design parameters, including the span length, available girder depth, average daily traffic (ADT) with the corresponding indicated number of heavy vehicles in the slow lane (N obs), and the paint maintenance schedule, on the optimal solutions. Furthermore, a sensitivity analysis is carried out to analyse the impact of inflation and discount rates on the obtained results. The results show that the concept of stainless steel corrugated web girders offers significant potential LCC and environmental impact saving for the examined span lengths, particularly in the case of deeper girders, high ADTs, and more intensive maintenance activities. Also, despite the influence of inflation and discount rates on LCC results, the studied concept consistently demonstrated favorable results. • Stainless steel corrugated webs for steel-concrete composite road bridge girders. • New bridge concept to minimize cost disparity between stainless and carbon steel. • New bridge concept for considerable LCC and environmental impact potential saving. • New bridge concept to eliminate the need for corrosion protection painting. • Stainless steel corrugated webs for material efficient bridge girders. [ABSTRACT FROM AUTHOR]

High-strength centrifugal precast (HSCP) reinforced concrete (RC) hollow pipe columns using grouted corrugated duct connection (GCDC) is a novel structure form in accelerated bridge construction (ABC). Nevertheless, the confinement effect of the HSCP hollow column core concrete provided by single-layer transverse rebar and its impact on ductility is not clear. Therefore, in this paper, the confinement effect and the ductility of hollow columns is studied using finite element analysis (FEA) method. A modified model is established to evaluate the constitutive relation of the core concrete confined by single layer transverse rebar. Based on the modified model, a simplified fiber model for predicting the hysteric response of HSCP hollow pipe column using GCDC, which considers bond-slip effect in GCDC joint was developed. The results indicate that the confinement effect of HSCP hollow pipe column is sensitive to the wall thickness ratio. When the wall thickness ratio decreases, the ultimate strain of the core concrete significantly decreases, while the effect on strength is not significant. The simplified model which considers confinement effect is more accurate in predicting the ductility of HSCP hollow columns. It proves that the weak confinement effects can lead to early cracking of the inner wall of hollow columns, which leads a significant impact on the ductility of HSCP hollow columns. Based on the parametric analysis, the peak load of the hollow column increases by 16.7% when the wall thickness ratio rises from 0.1 to 0.2, but only slightly changes when the wall thickness ratio is increased beyond 0.2. The wall thickness ratio of HSCP hollow pipe columns should be set above 0.2 to ensure the strength and ductility. In addition, a ductility evaluation method and a design example were developed to guide preliminary ductile design of HSCP hollow columns. • A modified model is proposed to predict the constitutive relation of HSCP hollow column core concrete. • A simplified fiber model is developed to predict the hysteretic response of HSCP hollow pipe columns using GCDC. • A ductility evaluation method is developed to guide seismic design of HSCP hollow pipe columns using GCDC. [ABSTRACT FROM AUTHOR]

Steel-concrete composite beams find extensive application in bridge construction, offering adaptability to complex terrains and structural advantages. Nevertheless, a persistent challenge lies in local instability, especially in steel beams with large aspect ratios. This study proposes stirrup-confined concrete-filled steel tube (CFST) composite beams as a solution to enhance structural performance by mitigating local instability. The research comprises comparative tests, numerical simulations, and theoretical examinations of rectangular CFST composite beams. Results demonstrate a significant improvement, with a 40% increase in flexural stiffness and a 10% increase in ultimate bearing capacity compared to traditional composite beams. Stirrup confinement effectively limits cross-section slip between the steel tube and infilled concrete, resulting in slip measurements of 0.72 mm at the end of loading. Examination of aspect ratios reveals substantial enhancements, showing a 65.6% increase in flexural stiffness and a 54.7% increase in ultimate bearing capacity as aspect ratios increase. Concrete strength grade exhibits minor effects, with slight improvements as the grade increases. Steel yield strength significantly influences ultimate bearing capacity, with a maximum 24.4% increase in higher-strength steel. Moreover, the steel content ratio enhances both flexural stiffness (up to 40.2%) and ultimate bearing capacity (up to 34.6%) with an increased steel ratio. Increased concrete slab thickness leads to improvements of up to 18.3% in flexural stiffness and up to 10.1% in ultimate bearing capacity. Formulas for predicting the flexural stiffness and bearing capacity of rectangular CFST composite T-beams are developed, offering practical guidance for optimizing their performance in structural engineering applications. • Comparative analysis shows CFST beams outperform traditional ones in stiffness and capacity. • Stirrups in CFST beams enhance steel-concrete bond, improving structural integrity. • Steel ratio and tube aspect are key in CFST beams' stiffness and capacity; other factors are less influential. • Formulas for calculating the flexural stiffness and bearing capacity of rectangular CFST composite T-beams are proposed. [ABSTRACT FROM AUTHOR]

• Elastic local buckling behavior and strength of flanges and webs in I-shape structural sections was investigated based on finite element analysis. • Effects of flange and web interaction on local buckling of flanges and webs was evaluated in terms of ratio of flange-web slenderness and height-to-width ratio. • Improved design equations of local buckling coefficients in flange and web bend buckling were proposed. • The proposed design equations shows a good correlation with FEA results when compared with equations in literature. Since using high–strength and high–performance steels has become a more common structural design practice in building and bridge construction, there is an increased potential for designing extremely thin-walled I-shaped beam members to enhance the efficiency of the steel beam design. For a more accurate design approach for these thin-walled I-beam members, particularly when they are near noncompact limits, it is necessary to explore more rational methods for determining the elastic local buckling strength of I-beams. This study aimed to investigate the local buckling behavior and strength of I-shape structural sections by considering flange-web interactions through three-dimensional finite element analysis. The goal was to provide a more reasonable estimation of local buckling strength under uniform bending. To evaluate the local buckling behavior of flange and web panels and explain it reasonably, this study adopted the ratio of flange-web slenderness (λ f / λ w) and height-to-width ratio (H / b f) of I-shaped beams which can affect buckling mode shapes and local buckling strength of I-shaped beams induced by flange local and web bend bucklings. Finally, this study presented design equations for both flange local and web-bend buckling coefficients considering λ f / λ w and H / b f. It was expected that the presented local buckling coefficients (k f) for flanges and webs could lead to a more reasonable design, as compared to the existing AISC design provisions. [ABSTRACT FROM AUTHOR]

This study conducted experimental investigations on the structural performances of link slabs which are constructed by using a newly developed hybrid-fibre reinforced engineered cementitious composite (hybrid-ECC). Both static and fatigue loadings were applied to validate the feasibility, provide a proof of concept study and demonstrate the benefits using hybrid-ECC for bridge link slabs application. Three identical quarter-scaled hybrid-ECC link slabs, simulating a link slab used for a typical 35-meter multi-span simply supported bridge, were fabricated. These slabs, denoted as LS-1, LS-2 and LS-3, were tested under designated static and fatigue loadings. Slab LS-1 was tested under static loading to obtain the flexural strength of the slab. Slabs LS-2 and LS-3 were tested under fatigue loadings to evaluate their fatigue performances under normal service loading and overload scenarios, respectively. Structural performances of these slabs in terms of deformation and crack width control capability, strain development on reinforcement bars and estimated service life were evaluated. It was observed that multiple microcracks were developed under both static and fatigue loadings. Slab LS-2 survived ten million cycles of service fatigue loading while LS-3 survived two million cycles of overload fatigue loading. For all the tests conducted under static and fatigue loadings, the maximum crack width observed on the three link slab samples was all controlled within the allowable limit of 0.2 mm until failure occurred. Based on the test results, it was estimated that if only the effects due to normal traffic loading and temperature variation were considered, the hybrid-ECC link slab could achieve a service life of more than 40 years. Therefore, the experimental study reconfirmed that the hybrid-ECC showed a high potential to improve the fatigue performance and extend the service life of link slab in bridge construction. [Display omitted] • Static and fatigue tests on three hybrid-ECC link slabs were conducted. • Fatigue performances of slabs under service and overload condition were investigated. • Tested slabs showed excellent deformation, cracking and damage control performance. • Estimated service life span of the tested slabs under service load was 40 years. [ABSTRACT FROM AUTHOR]

• Unbonded Fe-SMA bars are used as self-centering elements in ABC column. • Shake table tests are performed on 1/3-scale specimen with near-fault motions. • Observed residual drifts were smaller than a similar conventional column. • Pre-test finite model predictions are compared with the experimental measurements. Excessive seismic damage and residual deformation in bridge piers can result in time-consuming post-earthquake repair and replacement, which will adversely affect the recovery and seismic resilience of the transportation infrastructure. Seismic damage or permanent deformation in bridges can be minimized using advanced materials and novel technologies, of which shape memory alloy (SMA) has gained substantial momentum. The goal of this study is to investigate the feasibility of using unbonded iron-based shape memory alloy (Fe-SMA) bars as self-centering elements in accelerated bridge construction (ABC) piers to reduce residual seismic deformation. Shake table testing is performed on a one-third-scale bridge column specimen subjected to near-fault ground motions. A numerical model of the test specimen is developed in OpenSees, and the "pre-test" analysis results are compared with the experimental measurements. Acceptable correlations are observed between the simulated and measured residual drifts, accelerations, forces, and hysteretic responses. Furthermore, the test results are compared to that of a similar conventional cast-in-place RC column without self-centering elements. The maximum residual drift ratio in the tested Fe-SMA column specimen is found to be much smaller than the conventional column specimen highlighting the potential benefits of the proposed design. [ABSTRACT FROM AUTHOR]

This study investigates the early performance and potential issues of ultra-high-performance concrete (UHPC) light-weight composite decks (LCBDs) used in municipal highway bridge design. The major objective of this research was to understand the complex evolution of temperature and humidity within immature UHPC thin layers, which can lead to deformation and secondary stress, potentially causing cracks and threatening the long-term applicability and safety of steel-concrete composite bridges. Understanding of the mechanism of this process will be the basis for subsequent work. The early performance of UHPC with ordinary concrete is compared. Besides, discussions are conducted on the basic thermal conductivity theory of three-dimensional porous media and the hydration mechanism of cement-based materials that are appropriate for early-stage UHPC. Subsequently, a refined thermo-mechanical coupling analysis method for steel-UHPC LCBD was proposed, implemented using ABAQUS, and validated through a UHPC composite beam test. This method was applied to calculate the early shrinkage of the UHPC layer in a steel-UHPC LCBD and evaluate the risk of cracking in an actual bridge expansion project, providing a rationality evaluation of a bridge design and its construction procedure. • An approach for early shrinkage and crack assessment of UHPC light-weight composite bridge decks (LCBD) is suggested. • The aforementioned method is validated by an existing experiment and data therein. • Parametric analysis based on varying curing conditions of the composite beam is performed. • The design of the upper deck is evaluated, and construction & maintenance tips for a certain bridge project are proposed. [ABSTRACT FROM AUTHOR]