Steel-concrete Composite Bridge Research Articles

Flexural Performance of Steel–Normal Concrete–Ultra-High-Performance Concrete Composite Slabs with Steel Ribs

For steel–concrete composite bridges, the cracking of concrete in the tensile zone influences the serviceability of bridges and decreases their durability. UHPC, as a high-tensile and -durability material, is used to replace a part of the concrete to enhance the tensile performance. Thus, the steel–normal concrete–UHPC composite slab, as a new composite structure, is formed. This paper investigates the flexural behaviours of steel–normal concrete–UHPC composite slabs through a full-scale experiment, numerical simulation, and theoretical analysis. The research results indicate that (1) UHPC enhances the flexural performance of the tensile zone and delays the development of cracks. The initial cracking force of concrete increases from 44 kN to 91 kN. (2) UHPC effectively enhances the carrying capacity of composite slabs. A 50 mm UHPC layer makes the flexural bearing capacity of steel–concrete composite slabs increase by 13.51%. (3) The construction methods influence the initial cracking force of composite slabs. For full-span scaffolding construction, the initial cracking force decreases from 91 kN to 69 kN compared with construction without brackets. (4) The theoretical model considering the tensile contribution of cracking UHPC can accurately predict the bearing capacity of the composite slabs. And the theoretical values of the bearing capacity are lower than the experimental values, which makes the composite slabs safer in service.

Driving adaptability of highway steel-concrete composite beam bridge with multiple damages: theory, technology and practice

ABSTRACT To enhance the post-disaster highway driving speed evaluation system for steel-concrete composite beam bridge (SCCBB), a human-vehicle-bridge coupled driving adaptability analysis method is proposed. This method integrates considerations of both driving safety and comfort. Numerical simulation is employed to utilize a damaged SCCBB as the engineering context for studying vehicle rollover safety, vibration acceleration limits, and driving comfort. The analysis considers various vehicle types, including sedan cars, mini vans, motor buses, and trucks, resulting in recommended speed limits for each category. The study reveals that trucks demonstrate lower susceptibility to rollover accidents compared to sedan cars, mini vans, and motor buses under constant damage grade and vehicle speed conditions. However, increased damage grade and road surface roughness elevate rollover risks and diminish driver comfort. To ensure smooth post-disaster traffic flow on SCCBB and maintain acceptable driving comfort and speed levels, it is recommended to enforce speed limits: below 60 km/h for sedan cars, below 40 km/h for mini vans and motor buses, and below 80 km/h for trucks. The primary aim of this study is to provide technical guidance for the safe operation and maintenance of post-disaster SCCBB.

Experimental study on fatigue behavior of prefabricated high-strength steel-concrete composite bridge beams

To investigate the fatigue performance of prefabricated high-strength steel-concrete composite beams (P-HS-CCB), six specimens were designed with different fatigue load amplitudes, different fatigue load upper limits, and varying degrees of shear connection. Among them, specimen S560 underwent static failure testing, while the remaining five specimens underwent fatigue testing. The analysis was conducted from the perspectives of fatigue failure modes, fatigue life, and stiffness after specific cycles, with a comparison of the fatigue life calculation formula from different international codes. The results demonstrate that the fatigue failure mode of the P-HS-CCB is cracking in the vicinity of the steel beam at the mid-span, followed by crack propagation along both the web and flange widths. The P-HS-CBB exhibits excellent combination effects and anti-fatigue performance, maintaining nearly constant stiffness during fatigue loading with minimal composite section slip. The fatigue life of the P-HS-CBB is mainly influenced by the fatigue load amplitude during the testing. The S-N curve provided by AASHTO shows a good fit with the curve fitting based on experimental data and can be used to guide the anti-fatigue design of this type of beam.

Driving Comfort Analysis Method of Highway Bridge Based on Human-Vehicle-Bridge Interaction

Research on evaluating highway bridge performance through vehicle-bridge interaction (VBI) analysis has made significant advancements. However, when assessing driving comfort, using vehicle acceleration instead of human acceleration poses challenges in accurately representing comfort. First, the paper proposes a finite element analysis method for human-vehicle-bridge spatial interactions (HVBSIs). Then, the importance of wheel path roughness difference is explored when assessing driving comfort. Furthermore, a new method for evaluating driving comfort that includes human and vehicle vibration responses has been proposed, and a simulation example of the steel-concrete composite beam bridge (SCCBB) is used to verify the effectiveness of the proposed method. The results demonstrate that the HVBSI analysis method effectively simulates the interconnected vibrations of the human body, the spatial vehicle model, and the three-dimensional (3D) bridge model. Differences in wheel path roughness significantly impact the roll vehicle vibration responses, which are crucial in driving comfort analysis. The driver’s body vibration response is essential for evaluating driving comfort, and its inclusion leads to increased comfort indices values. In comparison to traditional methods, the overall vibration total value (OVTV) increases by a maximum of 109.04%, and the level of weighted vibration (Leq) increases by a maximum of 6.74%. This leads to an upgrade from grade IV to grade V in terms of comfort level, indicating a reduced comfort.

Structural Design and Mechanical Behavior Investigation of Steel–Concrete Composite Decks of Narrow-Width Steel Box Composite Bridge

Steel–concrete composite decks are commonly employed in narrow-width steel box composite girder bridges to augment their lateral spanning capabilities, while the concurrent omission of longitudinal stiffeners leads to a substantial reduction in the number of components, thereby yielding a structurally optimized bridge configuration. This paper delineates the structural design parameters of a narrow-profile steel box composite girder bridge and assess the mechanical behavior of its incorporated steel–concrete composite deck under static and fatigue loading conditions. To this end, two full-scale segment specimens from the composite bridge decks were subjected to equal amplitude cyclic fatigue tests. The investigation specifically concentrated on the impacts of two types of shear connectors—namely, perforated steel plates combined with shear studs and perfobond rib shear connectors (PBL connectors)—on the static and fatigue performance, including fatigue stiffness, of the steel–concrete composite bridge decks. The results indicate that, under the static bending condition, the composite deck specimen equipped with stud connectors demonstrates superior overall flexural stiffness in comparison to the specimen featuring PBL connectors. Furthermore, the flexural stiffness of the steel–concrete composite specimens experiences a negligible alteration across two million fatigue loading cycles. Upon the completion of two million fatigue loading cycles, the composite deck specimens incorporating the shear connectors composed of perforated steel plates and shear studs exhibit relatively wider crack widths under the static peak load. Both configurations of the steel–concrete composite bridge deck specimens manifest evident interfacial detachment, signifying insufficient tensile pull-out stiffness of the shear connectors. It is recommended to increase the quantity of the shear connectors or select the pertinent types in order to enhance the interface shear resistance.

Research on distributed strain monitoring of a bridge based on a strained optical cable with weak fiber Bragg grating array.

The foundation of an intelligent highway network is the construction of a high-density distributed strain monitoring system, which is based on sensing elements that can sensitively capture external information. In this research, the development and application for the structure of a novel strained optical fiber cable based on the weak fiber Bragg grating (wFBG) arrays are discussed. A modulation and demodulation solution of wavelength division multiplexing combined with time division multiplexing is developed by utilizing the property by which the wavelength of the strained optical fiber cable is periodically switched. Further, the strain transfer model of the optical cable is analyzed hierarchically using the theory of elasticity. The strain transfer coefficients of the overhanging region and the gluing region are combined to deduce the sensitivity model of the strained optical fiber cable. Moreover, the finite element technique is integrated to optimize the structural parameters of the optical cable for high-sensitivity or large-scale range. The strained optical fiber cable based on wFBG arrays is applied to a steel-concrete composite bridge. The static and dynamic loading tests show that the sensing optical cable can be monitored for strain variation in order to realize the functions of lane identification, weighing vehicle tonnage as well as velocity discrimination.

Fragility Analysis and Resilience Assessment of the Single-Column Pier Steel-Concrete Composite Bridge Subjected to Seismic Loads

Abstract With the advantages of a small footprint, wide under-bridge view, and beautiful appearance, single-column pier bridges are widely used in urban bridge networks. However, single-column pier bridges are prone to damage during earthquakes or heavy vehicle use, which can seriously affect normal operations and postdisaster recoveries. Therefore, there is an urgent need to carry out seismic resilience assessments of single-column pier bridges and formulate disaster prevention and mitigation measures from the aspects of design, maintenance, and postearthquake recovery. This paper first establishes a resilience assessment framework for the single-column pier bridge and optimizes a functionality recovery model after an earthquake. Then, a numerical model of a sample bridge is built for resilience fragility analysis. Nonlinear dynamic time history analysis is performed to build a probabilistic seismic demand model, and moment–curvature analysis is performed to build a probabilistic seismic capacity model. Finally, a seismic resilience assessment of the single-column pier bridge is obtained based on the seismic fragility, and a sensitivity analysis is carried out for the pier height, pier section dimension, span and vehicle load level to improve the resilience of the single-column pier bridge.

Application of high-performance cementitious composites in steel–concrete composite bridge deck systems: A review

Application of high-performance cementitious composites in steel–concrete composite bridge deck systems: A review

The Effect of Connection Ductility on Composite Steel–Concrete Bridges

Connection behavior significantly influences the design efficiency of steel–concrete composite bridges. This study investigates the impact of shear connectors, specifically headed stud connectors, on the structural response of symmetric and skewed composite steel–concrete bridges. Utilizing bilinear or trilinear slip–shear strength laws for studs, in line with the existing literature and code provisions, a finite element (FE) model is developed. This FE model is applied to a case study for composite deck analysis, incorporating variations in connection strength and ductility for nonlinear analyses. The study assesses ductility demands in connections for symmetric and skewed bridges of varying lengths and angles, considering both ductile and elastic designs. Results emphasize the importance of stud capacity, ductility, and strength on the overall bridge response, analyzing slip and shear trends at the interface. Skewed bridges, crucial for non-orthogonal crossings of roads, are integral to modern transportation infrastructure. However, skewness angles exceeding 20° can result in undesirable effects on stresses in the deck due to vertical loads. The results indicate that shear distribution in studs changes significantly as the skew angle increases, contributing valuable insights into optimizing bridge design. Thus, this research provides a comprehensive analysis of principles, design methodologies, and practical applications for both symmetric and skewed steel–concrete composite bridges, considering various parameters.

Estudo comparativo de soluções para vigas mistas empregas em obras de arte especiais ferroviárias

Abstract Steel-concrete composite bridges are a popular solution due to the structural benefits of both steel and concrete. The typical system of a concrete slab and steel I-girders for small and medium-span bridges often displays the most economical results. However, other solutions emerge as innovative alternatives for bridge construction, such as composite beams with composite dowels and pre-cambered composite beams. This paper aims to develop a comparative study of these composite beam solutions to delimitate their efficiency, performance, and economy. Thus, a case study for the superstructure of a two-way simply supported railway bridge is detailed to define the composite beam’s performance indicators. The innovative alternatives presented benefits when compared to the traditional system, demonstrating the positive impact of their use on bridges.

Study on early shrinkage and cracking of slab in UHPC light-weight composite deck based on ambient temperature and humidity effects

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.

Effective width of steel-concrete composite box girder bridges: a review and method comparison

Steel-concrete composite girders have non-uniform stress distribution on the slab, presenting maximum stresses next to the webs of the girder. This phenomenon is known as shear lag effect. To understand this effect, there is the effective width concept, in which only a portion of the slab width is considered effective in contributing to the composite element’s resistant capacity. However, in the technical standards, there is no recommendation for calculating the effective width in steel-concrete composite box girder bridges. In view of this situation, the purpose of this paper is to carry out a systematic review on effective width and/or the shear lag effect in steel-concrete composite bridges, in order to raise the main existing recommendations and compare them. Through a bibliometric scan with carefully chosen keywords, it was found that of all research on shear lag or effective width in steel-concrete composite structures, only 31.19 are on bridges and 14.97% are on bridges with box girders. Among the papers, those that have a method for calculating the effective width of steel-concrete composite girder bridges have been compared quantitatively and qualitatively with the procedures of AASHTO and EN 1994-2-2. In these procedures were also identified that the, for the boundary conditions of the present paper, the parameters that most influencing the effective width are, in that order, the span length, the distance between girders, the concrete slab height, the longitudinal position and the type of load.

Steel-Concrete Composite Bridge Diagnostics and Reconstruction

Abstract Many bridges in Slovakia are reaching their designed life span these days. Due to frequent errors during the construction of those bridges as well as bad maintenance, steel-concrete bridges are now in a critical state and urgent repairs of those structures are needed. In this article progressive methods of retrofitting existing concrete bridges are shown. In the presented method, the original pillars and original bridge deck will remain in their place, and on the existing deck new composite, steel-concrete bridge deck with encased steel members of progressive shape will be created. This method brings significant cost reduction for such retrofitting and enables the application of increased loads on the bridge.

Composite dowel's fatigue crack evaluation with loading patterns’ effect

Clothoid (CL)-shaped composite dowels are becoming popular in steel-concrete composite bridge construction recently. In this paper, CL-shaped dowel's fatigue performance is evaluated. Considering the contact between concrete and steel connector, two stress patterns of the connectors under the bending-shear action and the pure shear loading are simulated, and the detailed crack propagation analysis of the beam is carried out by using ABAQUS sub-model. The stress intensity factor is obtained to describe the fatigue performance of the composite dowel.

Experimental study on longitudinal shear behavior of prefabricated steel-concrete composite beams with notched connections

To address the fit-up issues caused by the interference between shear connectors and extended transverse bars, a novel deck-to-girder connection detail, notched connection, is applied to steel-concrete composite bridges with partial-depth deck panel (PDDP) systems. In the novel joint detail, protruding transverse reinforcement is replaced by evenly distributed notches at the ends of precast panels, and tie bars inserted in the notches are anticipated to resist longitudinal shear stress, achieving shear connection between steel girders and precast deck slabs. Considering the discontinuity of bottom transverse reinforcement, a four-point bending test was performed to investigate the longitudinal shear behavior of composite beams incorporating notched connections. Experimental findings indicate that the configuration of transverse reinforcement critically influences the failure modes of composite specimens, which involve crushing of concrete slabs, longitudinal shear cracking and splitting. Notably, tie bars sufficiently anchored in notches function equivalently to extended bars spliced by welding, and the specifically designed U-shaped notches enhance the anchorage performance of tie bars. Transverse reinforcing bars placed in the concrete topping prove more effective in resisting longitudinal shear than those in the bottom layer, and therefore asymmetrically reinforced concrete slabs experience reduced longitudinal shear cracking and splitting. Moreover, interface shear reinforcement effectively ensures the full composite action, while concentrated point loads can induce excessive local longitudinal shear stress. The study also provides design recommendations for notched connections.

Numerical simulation analysis of Steel-concrete Vierendeel Sandwich Plate Composite Bridge under a close-in blast loading

This study utilizes the CEL finite element method to investigate the performance of the Steel-concrete Vierendeel Sandwich Plate Composite Bridge (SVSPB) under the close-range blasting load. The effectiveness of the method is validated by reproducing experiments from the literature through numerical simulation. A three-dimensional model of SVSPB is established using Abaqus to analyze various aspects such as vertical displacement, slip between the reinforced concrete slab and the steel structure frame, failure mode, and material stress. The research findings indicate that: (1) SVSPB exhibits good ductility under explosive loads, as the overall structural framework retains a certain bearing capacity despite severe damage to the reinforced concrete slab. The structure also demonstrates favorable explosion venting performance. (2) Horizontal sliding occurs between the reinforced concrete slab and the steel frame in the absence of shear studs, highlighting the necessity of incorporating them. (3) During anti-riot design, attention should not only be given to the known weak points of the structure at the Bottom Chord nodes but also to the top chord nodes and stiffened plates of the main side beams on both sides. These findings offer reference in comprehending the dynamic response of SVSPB when subjected to explosive loads.

Ensemble Soft Computing Models for Prediction of Deflection of Steel–Concrete Composite Bridges

Ensemble Soft Computing Models for Prediction of Deflection of Steel–Concrete Composite Bridges

Study on the Shear Resistance Performance of Grouped Stud Connectors.

In order to further investigate the grouped stud effect on the force properties of stud connectors, based on the premise that the correctness of the finite element simulation method, in this paper, a finite element model of grouped stud connectors was developed, and the grouped stud effect and its sensitivity factors were analyzed in order to validate the recommended formula for calculating the shear capacity of grouped stud connectors. Results show that the number of grouped stud rows and stud row spacing have a significant influence on the grouped stud effect, and the unevenness coefficient of grouped stud force is negatively correlated with the number of grouped stud rows as well as the grouped stud row spacing. Grouped stud connectors with commonly used concrete grades greater than C50 and height-to-diameter ratios of greater than 4 in steel-concrete composite structural bridges are insensitive to changes in the concrete strength grades and the length of the studs. The direction of force transmission for grouped stud changes with the change in loading angle and the unevenness coefficient of force for the grouped stud will therefore be reduced. By comparing the results of the 62 existing groups of grouped stud connectors push-out tests, the mean of the tested to calculated value ratio was found to be 1.12, the variance was 0.023, the dispersion was small, and it was shown that the recommended formula has a high degree of accuracy. The results of this paper can be used as a theoretical basis for the study of the shear stress performance of grouped stud connectors.

Deep learning classifier for life cycle optimization of steel–concrete composite bridges

The ability to conduct life cycle analyses of complex structures is vitally important for environmental and social considerations. Incorporating the life cycle into structural design optimization results in extended computational durations, underscoring the need for an innovative solution. This paper introduces a methodology leveraging deep learning to hasten structural constraint computations in an optimization context, considering the structure’s life cycle. Using a composite bridge composed of concrete and steel as a case study, the research delves into hyperparameter fine-tuning to craft a robust model that accelerates calculations. The optimal deep learning model is then integrated with three metaheuristics: the Old Bachelor Acceptance with a Mutation Operator (OBAMO), the Cuckoo Search (CS), and the Sine Cosine Algorithms (SCA). Results indicate a potential 50-fold increase in computational speed using the deep learning model in certain scenarios. A comprehensive comparison reveals economic feasibility, environmental ramifications, and social life cycle assessments, with an augmented steel yield strength observed in optimal design solutions for both environmental and social objective functions, highlighting the benefits of meshing deep learning with civil engineering design optimization.

Impact of epistemic and aleatory uncertainties on the seismic reliability assessment of existing structures

Seismic reliability assessment of structural systems is commonly done via the convolution of seismic hazard and structural fragility to get resulting failure rate, and later compute seismic reliability index. Within this frame, many uncertainty sources have to be handled by the risk analyst, who is asked to make some reasonable assumptions in order to carry out his/her seismic safety quantification. However, slight changes in the definition of input parameters and/or the use of different empirical or analytical models can strongly impact the final reliability outcomes. The present work aims therefore to investigate the impact of different sources of uncertainties by comparing together key parameters to be defined in both hazard and fragility analysis, considering a case-study represented by an existing multi-span steel–concrete composite bridge to better understand which of these sources is more impacting on the final estimates. Results show how uncertainties associated to hazard and fragility are as a whole of the same order of magnitude and thus how both uncertainty sources have to be properly considered. In addition, a detailed sensitivity analysis was carried out for ranking the uncertainty sources in relation to their impact on the overall reliability index dispersion. Results showed that the choice of a suitable Ground Motion Prediction Equation (GMPE) model, the non-linear modelling technique and the number of the accelerometric records adopted for the structural analysis seem to be the factors that mostly contribute to the seismic reliability index variability, representing the uncertainty related to these parameters the majority of the overall reliability index dispersion.