Bridge Elements Research Articles

Estimation of the Service Life of Approach Slabs of Road Bridges Based on the Statistical Modeling Method

The article discusses the durability and reliability of a separate element – bridge approach slab, which is justified by the need to maintain a satisfactory technical condition of Ukrainian bridges in general and traffic safety on public roads with limited funding during martial law. The scope of the research is forecasting the residual service life of bridge elements (on the example of approach slabs) using probabilistic methods. Approach slabs are designed to smoothly and safely connect the road approach embankment with the bridge to gradually equalize the elastic modulus of the carriageway from a less rigid asphalt pavement on an elastic base to a more rigid one on a reinforced concrete slab. The main defects in the destruction of approach slabs are: changes in the longitudinal profile of the road due to the collapse and subsidence of the soil under the approach slabs; longitudinal and transverse cracks in the asphalt concrete pavement on the bridge approaches; and potholes that lead to an increase in the additional dynamic load on the bridge deck.

Implementation of High-Precision Life Cycle Cost Analysis (HP-LCCA) on Indonesian Bridge Management System

Life Cycle Cost Analysis (LCCA) is a method used to determine the preservation costs required for an object, in this case, a bridge, throughout its service life. This method has been implemented in several advanced countries, including Japan. The LCCA calculation concept in Japan differs from those in other countries, as it involves a detailed segmentation of structural elements of bridges, making the model unique and highly detailed. This model is known as High-Precision Life Cycle Cost Analysis (HP-LCCA) and will be tested for application in Bridge Management Systems (BMS) in Indonesia. Implementing this model requires several adjustments, including aligning perceptions of visual inspection results and adapting the assessment concepts for each element based on research interpretations. Additionally, the difference between non-physical and physical condition assessment models presents a challenge for adopting this calculation model. The research shows a similar pattern and positive correlation between non-physical and physical assessment models. Furthermore, factors influencing LCC calculations include bridge age and the number of segments in structural elements. This research aims to provide optimal LCC calculations and facilitate their application in BMS in Indonesia.

Fatigue and Ultimate Strength Evaluation of GFRP-Reinforced, Laterally-Restrained, Full-Depth Precast Deck Panels with Developed UHPFRC-Filled Transverse Closure Strips

A depth precast deck panel (FDDP) is one element of the prefabricated bridge element and systems (PBES) that allows for quick un-shored assembly of the bridge deck on-site as part of the accelerated bridge construction (ABC) technology. This paper investigates the structural response of full-depth precast deck panels (FDDPs) constructed with new construction materials and connection details. FDDP is cast with normal strength concrete (NSC) and reinforced with high modulus (HM) glass fiber reinforced polymer (GFRP) ribbed bars. The panel-to-girder V-shape connections use the shear pockets to accommodate the clustering of the shear connectors. A novel transverse connection between panels has been developed, featuring three distinct female-to-female joint configurations, each with 175-mm projected GFRP bars extending from the FDDP into the closure strip, complemented by a female vertical shear key and filled with cementitious materials. The ultra-high performance fiber reinforced concrete (UHPFRC) was selectively used to joint-fill the 200-mm transverse joint between adjacent precast panels and the shear pockets connecting the panels to the supporting girders to ensure full shear interaction. Two actual-size FDDP specimens for each type of the three developed joints were erected to perform fatigue tests under the footprint of the Canadian Highway Bridge Design Code (CHBDC) truck wheel loading. The FDDP had a 200-mm thickness, 2500-mm width, and 2400-mm length in traffic direction; the rest was over braced steel twin girders. Two types of fatigue test were performed: incremental variable amplitude fatigue (VAF) loading and constant amplitude fatigue (CAF) loading, followed by monotonically loading the slab ultimate-to-collapse. It was observed that fatigue test results showed that the ultimate capacity of the slab under VAF loading or after 4 million cycles of CAF exceeded the factored design wheel load specified in the CHBDC. Also, the punching shear failure mode was dominant in all the tested FDDP specimens.

Ultra-Low-Power, Extremely Stable, Highly Linear-Response Thermal Conductivity Sensor Based on a Suspended Device with Single Bare Pt Nanowire.

The continuous and stable monitoring by sensors is crucial for ensuring the safe utilization of hydrogen due to its inherent high explosiveness. Currently, catalyst aging and oxygen dependence often limit the lifetime of most sensors, which stems from the sensing materials and catalytic reaction in comparison to thermal conductivity sensors. Thermal conductivity sensors possess superior sensing characteristics such as lowpower consumption and exceptional stability attributed to their free-catalysts or free-oxygen nature. Herein, we present an ultralow-power hydrogen-thermal conductivity sensor based on suspended bare platinum nanowires. This sensor incorporates two suspended independent working elements (serpentine/bridge), each of which is thermally decoupled from the substrate. Also, the bridge element operates at significantly lower power levels (the lowest ∼3.32 μW) compared to existing direct-current hydrogen-thermal conductivity sensors. Furthermore, it demonstrates a 99.99% linearity between hydrogen concentration and response under various operating powers. Finally, our sensor shows remarkable stability through a repeatability test (>30,000 cycles). This developed platform provides an optimal structure scheme for integrated sensors with ultralow-power, extremely stable, highly linear-response sensing characteristics, which is expected to be widely used for hydrogen detection and leakage warning under various pipeline distribution systems.

Response of structural elements of temporary wooden bridges subjected to contact detonation

Response of structural elements of temporary wooden bridges subjected to contact detonation

Integration of BIM Tools for the Facility Management of Railway Bridges

Current railway infrastructure maintenance work, which is mostly carried out by visual inspection, has a reactive approach, dissociated information, and limited follow-up. On the other hand, railway bridges, being critical infrastructures, require effective monitoring and maintenance to guarantee their safety and operation over time. The designed tool links a parametric BIM model in Revit® with an automated spreadsheet in MS Excel® through visual programming in Dynamo, generating BIM/data automation as an initial step towards a digital twin. This achieves a bidirectional flow to exchange data on the structural condition of elements. The procedure was applied to a railway bridge in use for over 100 years, representing its geometry and damage information according to technical standards. The value lies in laying the foundations for adopting preventive approaches for this key infrastructure. The BIM/data automation allows the BIM model to visually reflect the condition of the elements, depending on their damage, consolidate the inspection information, and generate a visual management tool. In conclusion, the designed BIM/data automation improves the monitoring of railway bridges compared to traditional methods, facilitating the interaction and relationship between the damage records and the actual bridge elements, laying the foundations for the construction of digital twins.

Multi-layer Bundling as a New Approach for Determining Multi-scale Correlations Within a High-Dimensional Dataset

The growing complexity of biological data has spurred the development of innovative computational techniques to extract meaningful information and uncover hidden patterns within vast datasets. Biological networks, such as gene regulatory networks and protein-protein interaction networks, hold critical insights into biological features’ connections and functions. Integrating and analyzing high-dimensional data, particularly in gene expression studies, stands prominent among the challenges in deciphering these networks. Clustering methods play a crucial role in addressing these challenges, with spectral clustering emerging as a potent unsupervised technique considering intrinsic geometric structures. However, spectral clustering’s user-defined cluster number can lead to inconsistent and sometimes orthogonal clustering regimes. We propose the Multi-layer Bundling (MLB) method to address this limitation, combining multiple prominent clustering regimes to offer a comprehensive data view. We call the outcome clusters “bundles”. This approach refines clustering outcomes, unravels hierarchical organization, and identifies bridge elements mediating communication between network components. By layering clustering results, MLB provides a global-to-local view of biological feature clusters enabling insights into intricate biological systems. Furthermore, the method enhances bundle network predictions by integrating the bundle co-cluster matrix with the affinity matrix. The versatility of MLB extends beyond biological networks, making it applicable to various domains where understanding complex relationships and patterns is needed.

What makes us strong: Conceptual and functional comparisons of psychological flexibility and resilience

Psychological flexibility and resilience represent adaptive functioning and the pursuit of values in the presence of adversity such as during the COVID-19 pandemic. Understanding the conceptual and functional differences between these constructs is essential given their overlapping roles as key protective factors. This study involved 1059 participants from a Korean community sample who completed self-reported surveys measuring psychological flexibility, resilience, and mental health outcomes. Network analysis was used to create a sparse network comprising six nodes for psychological flexibility and ten nodes for resilience. Bridge strength centrality was estimated to identify the nodes connecting the two constructs. In addition, we employed a relative weights analysis to evaluate the relative significance of each psychological flexibility process on mental health outcomes while accounting for the composite resilience score. Within the psychological flexibility cluster, “Leaving thoughts be,” “Steady self,” “Awareness of value,” and “Being engaged” emerged as bridge elements, with “Steady self” exhibiting the highest bridge strength. Additionally, different patterns were observed in the unique contribution of each psychological flexibility process to positive and negative mental health outcomes. These findings suggest the potential role of “Steady self” as a catalyst for the transfer of skills and coping mechanisms between the different dimensions of psychological flexibility and resilience. The influential processes identified in this study had predictive value in their association with mental health outcomes. Future directions and implications are discussed.

USE OF GPR TECHNOLOGIES IN THE ROAD CONSTRUCTION INDUSTRY

The article continues the study on determining the possibility of applying ground penetrating radar (GPR) technologies in the road construction industry. The authors conduct research using an antenna unit that registers the cross-polarisation component of the reflected signal. In this case, processing the obtained radar images comes down to subtracting two mutually orthogonal components of the signal, which allows the determination of areas of the environment with anisotropic properties. Identifying and positioning extraneous inclusions, finding communications, and determining the location of reinforcement in roadway and bridge structures are relevant tasks. Their solution lies in studying the phenomenon of wave diffraction on extraneous inclusions of the investigated environment. Metal inclusions of different diameters are distinctly visible on radar images obtained during laboratory research. The laboratory studies conducted by the authors showed that the shape and nature of the hyperbola of the diffracted wave significantly depend on the object’s depth, diameter, and material. Therefore, further research in this direction should aim at studying the shape of the diffracted wave, which ultimately allows for judging the depth of occurrence and the diameter of a local extraneous inclusion. When finding and identifying reinforcement in structural layers of road surfaces and elements of bridges, difficulties arise due to the spacing of the reinforcing mesh. With a small reinforcing mesh spacing, when the wavelength is longer than the spacing, the reflections from the adjacent reinforcement bars merge into a common continuous boundary and make the lower layers of the structure almost indistinguishable. Solving the mentioned difficulties is possible by improving the equipment base and the algorithms for processing and interpreting the received radar images. Completed theoretical studies and computational experiments allow us to state that the development of road surface thickness measurement and defect detection techniques will become the basis of the road surface monitoring system using the subsurface geolocation method. Keywords: ground penetrating radar, radar image, road surface, dielectric constant, defect detection, thickness measurement, local inclusions.

Analysis of bridge structure selection using a hybrid decision-making technique

Implementation of sustainability principles in civil engineering has increased the substantive range of bridge engineering. The consideration of additional criteria, in particular ecological and social ones, requires the design process to be supported by appropriate tools. It refers especially to large bridge elements which affect their load-bearing capacity, e.g. girders or decks. The aim of this paper is to develop an original MCDA (Multi-Criteria Decision Analysis) method as a potential tool to support a decision-making process in the selection of material and design alternatives for bridge main girders. Therefore, an advanced hybrid algorithm was created consisting of the following methods: EA FAHP+FDEMATEL+ZUM (Extent Analysis Fuzzy Analytic Hierarchy Process + Fuzzy Decision-Making Trial and Evaluation Laboratory + Zero Unitarization Method), applied at the structure design stage. The pre-dimensioned alternatives selected for analysis were then subjected to an evaluation process based on a complex set of criteria arranged in a hierarchical control structure (HCS). The algorithm has been applied based on the example of a medium span slab-and-girder bridge, assuming 6 alternative concepts of girders, different in material and dimensions. The hybrid method was compared with the EA FAHP method. Analysis results obtained based on judgments from 3 teams of Decision Makers (DM) indicate effectiveness of the proposed algorithm and its practical aspect, which may contribute to improved quality and safety of bridge structures.

THE METHODS OF THE SORBED QUANTITY OF THE DIFFUSION COEFFICIENTS AND POLYMERS LIQUID AREAS

The article presents the application of a method for assessing the qualitative state of bridges based on the use of qualimetry methods. The proposed approach considers a wide range of parameters that affect the functioning and reliability of road bridges. The method involves the use of a qualimetric model that allows systematizing and structuring of information about the physical condition of individual bridge elements and functional indicators. The weighting of the parameters was determined using expert and estimated methods, which increased the accuracy and objectivity of the assessment. The development of a qualitative condition model includes the following stages: identification of bridge elements, determination of assessment parameters, development of a qualimetric model, determination of weighting coefficients for each criterion, analysis of the results of a specific object inspection, and determination of the overall operational condition of the bridge. The results of the study show that the proposed methodology can be effectively used to assess the condition of bridges, providing a sufficiently high accuracy and completeness of the assessment. This contributes to improving the safety and reliability of bridge structures, reducing accidents and optimizing their maintenance costs. The proposed assessment method has prospects for implementation in the practice of bridge condition management and can be further applied in the system of monitoring the condition of transport facilities.

ДОСЛІДЖЕННЯ МІЦНОСТІ БЕТОНУ НЕРУЙНІВНИМИ ТА РУЙНІВНИМИ МЕТОДАМИ

Introduction. As a result of the military aggression of the Russian Federation against Ukraine, there is an urgent need to restore damaged and destroyed structures. Depending on the material of the span structure, bridges are divided into reinforced concrete, metal, steel-reinforced concrete, stone and wooden. Reinforced concrete bridges are the most common in Ukraine. Such structures account for almost 94 % of the total number of all bridges. Even if the bridge span is made of metal beams, such structures often have a reinforced concrete overlay slab, which means that reinforced concrete is also an integral load-bearing part of the bridge that requires proper maintenance during operation and, if necessary, repair or restoration work. In order to determine the technical condition of span structures, it is first of all necessary to inspect the structure. Typically, the list of inspection activities includes testing the concrete of structures for compressive strength. Therefore, determining the physical and mechanical characteristics of concrete is an integral part of planning for major repairs, reconstruction or new construction. This paper investigates different methods for determining the concrete strength of bridge elements. The accuracy of the results of different methods in laboratory conditions is analyzed. Problem statement. The use of a particular method has its advantages and disadvantages, which, in turn, can affect the accuracy of the data obtained.

Acoustic emission technology-based waveguide localization method for damaged internal tendons of in-service post-tensioned hollow slab bridges

Prestressing tendons are crucial load-bearing elements in post-tensioned hollow slab bridges. Damage to these tendons significantly reduces the safety, functionality, and longevity of the bridge. Regular monitoring of prestressing tendons is essential for bridge operation. Acoustic emission technology, known for its high accuracy and sensitivity to minor vibrations, is a key technique for monitoring bridge cables. This study proposes a novel dual-sensor acoustic emission localization method for detecting tendon damage in post-tensioned hollow slab bridges, utilizing waveguide technology. The effectiveness of this method is confirmed through hammering tests that simulate acoustic emission damage on operational hollow slab bridges. The proposed method, requiring only two sensors, offers a cost-effective alternative for monitoring the entire span of post-tensioned hollow slab bridges, so that effectively reduces the cost of bridge health monitoring and is easy to be promoted in actual engineering projects.

Stability of Beam Bridges Under Bridge-Vehicle Interaction

In this paper, we provide an accurate and reliable formulation for simulating the interactions of both train/bridge subsystems and suitable for high-speed railway lines as well as for existing lines worldwide that are being renewed or modernized. We model the train as a series of suspended masses, taking into account the energy dissipation and the suspension system for each train vehicle. On the other hand, the bridge supporting the rails with irregular elevations will be modeled as an Euler-Bernoulli beam. The mathematical formulation of the interaction problem between the two subsystems requires the writing of two sets of equations, which interact with each other through contact forces. Using a one-dimensional finite element formulation, a series of equations are constructed by Modeling the beam structure. In addition, the suspended mass equations are first discretized using Newmark's finite difference formulas, which then reduce the degrees of freedom (DOF) of the vehicle to those of the bridge element. This solves the coupling problem between the two subsystems. The derived component is known as the vehicle/bridge interaction (VBI) element. On the other hand, an iterative procedure will be used subsequently to solve the non-linearity problem of the resulting system of differential equations. MATLAB programs provide results that identify the critical parameters influencing the bridge's dynamic stability.

Defect modelling and correlation mapping for bridge inspection

PurposeThis paper covers the development of a novel defect model for concrete highway bridges. The proposed defect model is intended to facilitate the identification of bridge’s condition information (i.e. defects), improve the efficiency and accuracy of bridge inspections by supporting practitioners and even machines with digitalised expert knowledge, and ultimately automate the process.Design/methodology/approachThe research design consists of three major phases so as to (1) categorise common defect with regard to physical entities (i.e. bridge element), (2) establish internal relationships among those defects and (3) relate defects to their properties and potential causes. A mixed-method research approach, which includes a comprehensive literature review, focus groups and case studies, was employed to develop and validate the proposed defect model.FindingsThe data collected through the literature and focus groups were analysed and knowledge were extracted to form the novel defect model. The defect model was then validated and further calibrated through case study. Inspection reports of nearly 300 bridges in China were collected and analysed. The study uncovered the relationships between defects and a variety of inspection-related elements and represented in the form of an accessible, digitalised and user-friendly knowledge model.Originality/valueThe contribution of this paper is the development of a defect model that can assist inexperienced practitioners and even machines in the near future to conduct inspection tasks. For one, the proposed defect model can standardise the data collection process of bridge inspection, including the identification of defects and documentation of their vital properties, paving the path for the automation in subsequent stages (e.g. condition evaluation). For another, by retrieving rich experience and expert knowledge which have long been reserved and inherited in the industrial sector, the inspection efficiency and accuracy can be considerably improved.

Friction Characteristics and Lubrication Properties of Spherical Hinge Structure of Swivel Bridge

A spherical hinge structure is a key swivel bridge element that must be considered when evaluating friction characteristics and lubrication properties to meet the rotation requirement. Polytetrafluoroethylene (PTFE)-based spherical hinge sliders and lubrication coating have been employed for over 20 years, but with the growing tonnage of swivel bridge construction, their capacity to accommodate the required lubrication properties can be exceeded. In this manuscript, the optimal friction coefficient of the spherical hinge is obtained through the finite element analysis method. Four lubrication coatings and four spherical hinge sliders are prepared and tested through a self-developed rotation friction coefficient test, four-ball machine test, dynamic shear rheological test, and compression and shear performance test to evaluate the lubrication and friction properties of the spherical hinge structure. The results of the finite element analysis show that the optimum rotation friction coefficient of the spherical hinge structure is 0.031–1.131. The test results illustrate that the friction coefficient, wear scar diameter, maximum non-seize load, phase transition point, and thixotropic ring area of graphene lubrication coating are 0.065, 0.79 mm, 426 N, 14.6%, and 64,878 Pa/s. The graphene lubrication coating has different degrees of improvement compared with conventional polytetrafluoroethylene lubrication coating, showing more excellent lubrication properties, bearing capacity, thixotropy, and structural strength. Compressive and shear tests demonstrate that polyether ether ketone (PEEK) has good compressive and shear mechanical properties. The maximum compressive stress of PEEK is 87.7% higher than conventional PTFE, and the shear strength of PEEK is 6.07 times higher than that of PTFE. The research results can provide significantly greater wear resistance and a lower friction coefficient of the spherical hinge structure, leading to lower traction energy consumption and ensuring smooth and precise bridge rotation.

Splice Length of Large Diameter Reinforcing Bars in Ultra-High-Performance Concrete

Potential exists for construction time savings through replacement of cast-in-place substructure columns, piers, or both, with prefabricated bridge elements and systems. Cast-in-place substructure construction requires forming, placing steel, and pouring concrete at the construction site. Using prefabricated elements would decrease the extent of work required at the site and potentially reduce concrete curing time. This research furthers the effort to use ultra-high-performance concrete (UHPC) as a joining material for prefabricated bridge substructure elements. UHPC has a high early strength, requires less development or splice length than conventional concrete, and has been used previously for accelerated construction projects, such as bridge deck replacement with precast units. UHPC also has a discontinuous pore structure that reduces liquid ingress, significantly enhancing durability compared to conventional concrete. Although UHPC has been researched extensively, previous research for reinforcing bar splice and development lengths has focused on #9 and smaller diameter bars. Typically, larger diameter bars are used for substructures. This research determined the required splice lengths for large diameter steel deformed reinforcing bars embedded in UHPC based on 127 individual tests. Three primary variables were included in the testing matrix: bar size, bar spacing, and concrete cover. To achieve at least 75 kips per square inch (ksi) (517 MPa) reinforcing bar stress in UHPC with an early age strength of 14 ksi (97 MPa), the required embedment length ranges from 8 to 13 times the bar diameter and the corresponding splice length varies from 6 to 11 times the bar diameter, depending on the bar size and concrete cover.

Free-Vibration Analysis for Truncated Uflyand–Mindlin Plate Models: An Alternative Theoretical Formulation

Plates are flat structural elements whose thickness is small in relation to the size of the surface. Their use may include engine foundations, reinforced concrete bridge elements or parts of various floating structures. Consequently, knowledge of their mechanical behavior under static and dynamic loads is of primary importance in engineering applications and of interest from a structural point of view. As a result, numerous works existing in the literature have investigated the mechanical properties of plates using various plate models, such as Reissner’s theory, Levinson’s theory, Kirchhoff’s theory and Mindlin’s theory, and their static and dynamic behavior has been examined. In the present paper the truncated Uflyand–Mindlin plate equation is proposed. According to Uflyand–Mindlin theory, an alternative theoretical formulation is presented for the free-vibration analysis of plates, and the equations of motion and the general corresponding boundary conditions are derived. This paper develops the truncated Uflyand–Mindlin plate equation, i.e., without the fourth-order derivative, by means of the direct method and variational formulation. The first-order shear deformable plate theory developed by Elishakoff, which takes into account rotational inertia and shear deformation and does not include a fourth-order time derivative, is variationally derived here. This derivation complements that performed by Mindlin some 70 years ago. The innovative aspect of the suggested strategy is that variational and direct methods for studying plate dynamics are analogous. Finding the third equation of the reduced Uflyand–Mindlin equations, the accompanying boundary conditions and their mathematical resemblance are the goals of the presented formulations. In order to solve the dynamic equilibrium problem of a truncated Uflyand–Mindlin equation via a variational formulation, it is demonstrated that the differential equations and the corresponding boundary conditions have the same form as those found using the direct technique. This paper successfully completes this task. Finally, in order to validate the effectiveness and correctness of the proposed procedure, a numerical example of the case of a plate simply supported at all four ends is proposed.

Improving the survivability of a railway bridge with damage to a truss members

In the modern era, accidents and damage to individual structural elements of bridges are frequently recorded, so the issue of bridges survivability, as the ability to pass the transport load with damaged elements, is becoming more and more relevant. The timeliness is confirmed by the inclusion of new requirements for survivability testing in modern bridge design standards. The article gives a publications review in the field of survivability theory development, identifies the methods of its increase in relation to transport structures and conducts research on increasing the railway bridges survivability. The research review in the field of assessment and increase of structures survivability as applied to transport structures allowed to single out the methods of survivability increase by providing bearing capacity of structures key elements, optimisation of spatial performance of a building structure and development of special organisational measures of emergency situation exclusion. With regard to the superstructure with through main trusses of a railway bridge with a design length of 66 m, numerical methods have been used to investigate the possibilities of increasing the reliability by increasing the bearing capacity of key elements. It has been established that the positive effect of increasing the survivability by excluding the bottom chord member and struts from operation gives an increase in the bearing capacity of the bottom lateral bracing and struts, respectively. It is revealed that the most dangerous is the exclusion from operation of the upper chord truss members, and the bearing capacity increase of the key lateral bracing elements, as well as the increase of the degree of static indeterminacy of the lattice of links is ineffective. Organisational measures in case of damage and failure of the span truss element are proposed.

FE Analysis of Suspension Bridges Based on Extended Deflection Theories with Extensible Hangers and Floating Girders

This paper presents extended deflection theories of multi-span continuous suspension bridges and their FE formulations using the energy method. The proposed deflection theories take into account effects of hanger extensibility, free sliding of main cables at the saddle, and floating girders. Suspension bridge elements consisting of main girder, main cable, and tower elements are then introduced and simplified FE formulations are rigorously proposed to solve the extended deflection theories. In order to demonstrate the validity and accuracy of the presented formulation, three/four-span suspension bridge models having regular and floating support conditions of the main girder are analyzed using the simplified FEMs, and the analysis results are compared with those by the unstrained length method, which is a sophisticated FEM. Finally, three virtual earth-anchored suspension bridge models are analyzed to explore the effects of hanger extensibility.