Box Girder Research Articles

Seismic Damage Analysis of Zamora Bridge in Ecuador

The Zamora Bridge, located in the Zamora-Chinchipe Province in the southeastern part of Ecuador, on the Pacific Rim seismic belt, serves as the sole river-crossing channel from the Mirador Copper Mine area to the exterior. Constructed and opened for traffic in 2013, this bridge is designed as a low-pier continuous girder bridge, featuring a three-span prestressed concrete continuous box girder for the main beam, with a span arrangement of 45.5+140+45.5 meters, and utilizes basin-type rubber bearings throughout. On May 6, 2019, and November 28, 2021, the Zamora Bridge experienced two significant seismic events. The initial seismic damage investigation revealed that the piers and foundation maintained their load-bearing capacity largely intact; the basin-type rubber bearings predominantly suffered shear failure and displacement, losing their horizontal limit capacity. Additionally, abutment blocks sheared, padstones cracked locally, and the main girder exhibited residual displacement. Following the first earthquake, repair work was undertaken based on the damage results, switching to friction pendulum seismic isolation bearings to enhance the seismic resilience of bridge. The subsequent seismic damage assessment indicated the overall stable condition of the bridge, with no observable damage, deformation, or settling to the main structure, thus maintaining basic traffic functionality. However, shear and deformation occurred to the bolts and pins fixing the direction of the friction pendulum isolation bearings, along with residual displacements after the activation of the seismic isolation function, and cracks developed in the abutment padstones and mortar layers. To delve into the performance and damage probability of vulnerable components of low-pier continuous girder bridges under various seismic intensities, numerical models of the Zamora Bridge equipped with basin rubber bearings and friction pendulum bearings were separately established using OpenSees finite element software. An analysis of the bearings' longitudinal seismic susceptibility was conducted by integrating the demand-capacity ratio and IDA method. The findings indicate that bearings, padstones, and anchor bolts are the vulnerable components necessitating reinforcement for such bridges. Compared to the basin rubber bearings, friction pendulum bearings significantly reduce the probability of bearing damage and demonstrate an excellent seismic isolation effect.

Research Progress on Shear Characteristics and Rapid Post-Disaster Construction of Narrow-Width Steel Box–UHPC Composite Beams

The narrow-width steel box girder is an important type of steel–concrete composite bridge structure, which is usually composed of reinforced concrete wing plates, narrow steel boxes partially injected with concrete, and shear connectors that promote shear force transfer. The utilization of narrow-width steel box girders, augmented by partially filled concrete, embodies the synthesis of steel and concrete elements, fostering structural efficiency. Moreover, its attributes, including reduced structural weight, diminished vertical profile, enhanced load-bearing capacity, and augmented stiffness, have prompted its gradual integration into bridge engineering applications. In this study, the calculated values of shear strength under three current design codes were reviewed, and the shear failure phenomena and its determinants of narrow-width steel box–ultra-high-performance concrete (UHPC) composite beams under negative bending moment conditions were investigated, which were mainly determined by shear span ratio, concrete wing plate, UHPC steel fiber content, UHPC plate thickness, and transverse partition inside the box. Concurrently, this paper evaluates two innovative structural designs, including a double-narrow steel box girder and a three-narrow steel box girder. In addition, strategies to reduce crack formation under the negative bending moment of long-span continuous narrow and wide box girder abutments are discussed, and we show that this measure can effectively control the formation of cracks to support the negative bending moment zone. At the same time, the scope of the application of a narrow-width steel box girder composite bridge is reviewed, and the conclusion is that a narrow-width steel box girder is mainly used in small-radius flat-curved bridges or widened-ramp bridges with a span of 30 m or more in interworking areas and in the main line with a 60–100 m span in mountainous or urban areas. Finally, the research direction of the shear resistance of the UHPC–narrow steel box girder under negative bending moments is proposed.

A Shear Strength Prediction Theory for Box Girder Strengthened by External Vertical Prestressing Reinforcements

A Shear Strength Prediction Theory for Box Girder Strengthened by External Vertical Prestressing Reinforcements

Investigation into Discrepancies in Alignment and Levelling of Precast Segmental Box Girders (SBGs) During Launching for LRT 3, from Bandar Utama to Johan Setia (Package GS10)

In recent decades, there has been a notable global increase in the utilization of precast concrete segmental bridges within construction projects. However, discrepancies have been observed in the height of precast Segmental Box Girders (SBGs) installed alongside PS1 (monolithic), deviating from project specifications. This discrepancy impacts the deck level and consequently influences the Top of Rail (TOR). Consequently, a study was undertaken at AlKauthar Kinematics Sdn Bhd, a company involved in the LRT3 project's construction, with a specific focus on the casting and installation of Segmental Box Girders. The study's objectives include identifying the factors contributing to precast SBG misalignment during the LRT3 project's launch at P25-08, analyzing data for realignment purposes, and proposing design methodologies for manufacturing SBGs. The methodology employed in this study entails the analysis of data sourced from the industry, utilizing As-Built Surveys conducted by surveyors. Findings indicate that precast SBG misalignment during launching at P25-08 is primarily attributed to on-site errors, particularly casting errors during the construction of the cast-in-situ monolithic segment P25-08. This insight is invaluable for both governmental bodies and private construction organizations in mitigating project setbacks.

Modelling of foundation stiffness beneath intermediate support of 178 m long integral viaduct

The paper presents three methods of modelling of foundation stiffness beneath intermediate support of a 178 m long integral box girder viaduct and its impact on the values and distribution of displacements and internal forces in the pier of this support. The pier support is made of cast in situ reinforced concrete of strength class C50/60. For the analysis, three models were built in Abaqus FEA software. The first model A3D in Fig. 1 represents a complex three-dimensional model. The second L2D and the third H2D model shown in Fig. 2 represent simple two-dimensional models. The stiffness of the subgrade beneath the structure in the second and third model was modelled as spring constants calculated based on the equations given in the reference [8] model L2D and [10] model H2D. The middle range value of Young’s modulus for sand and gravel was used to calculate the subgrade stiffness parameters. In all models, a horizontal displacement in the Y direction of value 20 mm and a vertical force of value 18200 kN were applied to the top of the pier support. The horizontal displacement was caused by the thermal longitudinal expansion of the six-span viaduct deck and the braking force. The vertical force was caused by the dead, superimposed, and live loads acting on the viaduct deck. Finally, the values and distributions of displacements and internal forces in the pier support from the complex model were compared with the values in two simple models. The author focuses on the method of modelling of foundation stiffness of the pier support and its impact on the values of displacements and internal forces in the pier support. A similar structure analysed in this paper was design-checked by the author in Ireland [4].

A field study of temperature field distribution characteristics of flat steel box girder and its influential environmental factors

As one of the mainstream girder types of long-span bridges, the flat steel box girder (FSBG) under thermal action has been one primary concern for bridge engineers and researchers. This research presents a field study of the temperature field distribution characteristics of FSBG and its influential environmental factors. To achieve this, an acquisition equipment that comprises of thermometers and environmental sensors is applied to a prototype cable-stayed bridge under construction, in which the structural temperature field of FSBG and the surrounding environmental data are collected and analyzed thoroughly. The results indicate that the vertical temperature distribution (VTD) in certain time instants exhibits significant variations and the maximum vertical temperature gradient can reach up to 27.9 °C. Despite of this, it is found that the VTD of FSBG can be covered by several current standards such as AASHTO standard and New Zealand standard. As for the transverse temperature distribution (TTD), it is found that both the variation and temperature difference of TTD in certain time instants are considerable, especially at the deck surface, which far exceed those of the TTD prescribed in current standards. This indicates that the TTD of FSBG should be seriously considered during the bridge design phase. Furthermore, the field study reveals that the wind speed has negative effect on the structural temperature of FSBG (when the air temperature is less than that of FSBG), while the solar radiation exerts positive effect on the structural temperature of FSBG. The outcome of this study can provide valuable references for thermal design, monitoring and control of long-span bridges employing FSBGs as bridge main girder.

Damage detection for high-speed railway standard box girders based on time–frequency characteristics of train-induced strain

This paper presents a novel approach for detecting damage in high-speed railway standard box girders by leveraging the time–frequency characteristics of train-induced strain. Based on the mechanical and deformation characteristics of high-speed railway box girders, the method involves segmenting the box girder into distinct components based on plate element analysis to identify their damage separately. It utilizes coefficients derived from wavelet transforms as indicators sensitive to damage, and employs the particle swarm optimization algorithm (PSO) to determine the ideal frequency intervals in terms of number and position. Within these optimal frequency intervals, the sum of wavelet coefficients is only sensitive to damage features while remaining unaffected by environmental and operational variations. A convolutional denoising autoencoder is employed to remove noise from the strain time–frequency image, improving the robustness of the proposed method. By utilizing the Gaussian inverse cumulative distribution function to estimate confidence boundary (CB) for damage features (DF), outliers are detected, allowing for precise damage localization and quantification. A case study for the high-speed railway box girder show that the proposed method can effectively identify, locate and quantify damage across all components in the critical key section by using data acquired from just 4 strain sensors. This method holds promise for facilitating the development of effective maintenance strategies for high-speed railway box girders.

Characterization of the static and dynamic response of a post-tensioned concrete box girder bridge with vertically prestressed joints showing vertical deflections due to concrete creep deformation

Characterization of the static and dynamic response of a post-tensioned concrete box girder bridge with vertically prestressed joints showing vertical deflections due to concrete creep deformation

Flexural and shear load rate evaluation on Pre-stressed concrete Box Girder Superstructure under the effect of IRC Loading

Flexural and shear load rate evaluation on Pre-stressed concrete Box Girder Superstructure under the effect of IRC Loading

The effect of dynamic soil-structure interaction on the response of periodic box girder bridges

The effect of dynamic soil-structure interaction on the response of periodic box girder bridges

Wave Forces on a Submerged Bridge Deck with a Box Girder Situated over a Step Bottom

Wave Forces on a Submerged Bridge Deck with a Box Girder Situated over a Step Bottom

Vibration-based system identification of a large steel box girder bridge

Vibration-based system identification of a large steel box girder bridge

Application of Multi-Channel Synchronized Dynamic Strain Gauges in Monitoring the Neutral Axis Position and Prestress Loss of Box Girder Bridges.

The aim of this paper was to explore the application of multi-channel synchronized dynamic strain gauges in monitoring the neutral axis (N.A.) position of prestressed concrete box girders. The N.A. position has recently been proposed as an indicator for monitoring the health of bridge structures. Laboratory experiments were conducted on a prestressed T-beam under different prestress level conditions to investigate the correlation between the prestress magnitude and the N.A. position. In the development of the multi-channel synchronized dynamic strain gauges, edge computing was employed to significantly reduce the amount of data transmitted from the sensor nodes on-site. In edge computing, only the dynamic strain response caused by the maximum vehicle load in each minute is transmitted. This approach greatly enhances the monitoring efficiency and enables the realization of on-site non-computer-based monitoring systems. The laboratory test results of the prestressed T-beam showed that the N.A. position tends to move slightly downward as the prestress force increases. In other words, when the prestress force decreases due to loss, the N.A. position exhibits a slight upward movement. This study selected a newly constructed prestressed box girder as the subject for on-site measurement of the N.A. position using multi-channel synchronized dynamic strain gauges shortly after the prestress was applied. The on-site monitoring data indeed revealed a gradual upward movement of the N.A. position. This phenomenon confirmed that soon after the completion of prestressed concrete bridges, there is a gradual loss of prestress due to the significant shrinkage and creep effects of the early-age concrete. The on-site monitoring result aligned with the findings from the laboratory experiments, where the N.A. position was observed to move upward as the prestress decreased.

Damage analyze of prestressed small box girder bridges under explosive loading of vehicle

Damage analyze of prestressed small box girder bridges under explosive loading of vehicle

Research on safety condition assessment methodology for single tower steel box girder suspension bridges over the sea based on improved AHP-fuzzy comprehensive evaluation

In order to propose a reliable method for assessing the safety condition for single-tower steel box girder Suspension bridges over the sea, a condition monitoring system is established by installing sensors on the bridge structure. The system is capable of gathering monitoring data that influence the safety status of the bridge. These include cable tension, load on the main tower and pylon, bearing displacement, wind direction, wind speed, and ambient temperature and humidity. Furthermore, an improved Analytic Hierarchy Process (AHP) algorithm is developed by integrating a hybrid triangular fuzzy number logic structure. This improvement, coupled with comprehensive fuzzy evaluation methods, improves the consistency, weight determination, and security evaluation capabilities of the AHP algorithm. Finally, taking the No.2 Channel Bridge as an example and based on the data collected by the health monitoring system, the application of the safety assessment method proposed in this paper provides favorable results in evaluating the overall safety status of the bridge in practical engineering applications. This provides a basis for management decisions by bridge maintenance departments. This project confirms that the research results can provide a reliable method for assessing the security status of relevant areas.

A one-dimensional high-order dynamic model for twin-cell box girders with deformable cross-section

A one-dimensional high-order dynamic model for single-box twin-cell box girders is presented together with the pattern recognition algorithm. The model takes into account the deformable cross-section and can accurately predict its 3D dynamic behaviors. The cross-section deformation is captured by basis functions satisfying displacement continuity condition, which is essential to construct the initial model formulation based on the Hamilton principle. The axial variation patterns of generalized coordinates are decoupled by solving the eigenvalue problem. On this basis, the combinations of basis functions are obtained to bring out cross-section deformation. The cross-section deformation, hierarchically organized and physically meaningful, are used to update the basis functions in the reconstructed high-order model. Numerical analysis has verified the accuracy and applicability of the reconstructed one-dimensional high-order model.

Fire effect of steel bridge structure with consideration of leaked combustion fuel on asphalt bridge deck

In this paper, a fire load model is introduced for steel bridge decks considering asphalt pavement layers, aimed at exploring the consequences of fire arising from fuel leakage on the bridge pavement. Temperature data, mass loss rates, and radiation measurements from the pavement during fire tests are collected. The fire process on the bridge deck is categorized into four distinct stages, based on the mass loss rate. The temperature-time model is constructed by fitting the temperature data from the first two stages on the top surface. This model is then validated by comparing the temperature data obtained from various temperature-time load inputs with the experimental data from the middle and bottom surfaces. Additionally, a finite element numerical model is developed for a steel box girder bridge, enabling a comparison of different temperature-time models to establish the rationality of the bridge deck temperature-time model. Finally, the thermal mechanical coupling method is employed to investigate the impact of fire on the bridge's mid-span, revealing a close alignment between the simulation temperatures derived from the bridge deck temperature-time curve and the experimental results.

Experimental Study on Shear Lag Effect of Long-Span Wide Prestressed Concrete Cable-Stayed Bridge Box Girder under Eccentric Load

Based on the engineering background of the wide-width single cable-stayed bridge, the shear lag effects of the cross-section of these bridge box girders under the action of the eccentric load were experimentally studied. The behavior of shear lag effects in the horizontal and longitudinal bridge directions under eccentric load in the operational stage of a single cable-stayed bridge was analyzed by a model testing method and a finite element (FE) analytical method. The results showed that the plane stress calculation under unidirectional live load was similar to the results from spatial FE analysis and structural calculations performed according to the effective flange width described in the design specification. At the position of the main beam near the cable force point of action, the positive stress at its upper wing edge was greatest. At a distance from the cable tension point, the maximum positive stress position trend showed that from the center of the top flange to the junction of the top flange and the middle web to the junction of the top flange and the middle web and the side web. Under eccentric load, the positive and negative shear lag effects on the end fulcrum existed at the same time, and the shear lag coefficient on the web plate was larger than the shear lag coefficient on the unforced side. Due to the influence of constraint at the middle fulcrum near the middle pivot point, positive and negative shear lag effects were significant, and the coefficient variation range was large, resulting in large tensile stress on the roof plate in this area. According to FE analytical results, stress and shear forces of a single box three-chamber box girder under eccentric load were theoretically analyzed, the bending load decomposed into the accumulation of bending moment and axial force, using the bar simulation method, and the overall shear lag effect coefficient λ was obtained and verified.

Assessment of residual prestress in existing concrete bridges: The Kalix bridge

The direct socio-economic consequences of the deterioration of aging infrastructure systems have triggered a continuous process of revising and updating current design standards and guidelines for critical network components. Specifically, long-term degradation processes demand the analysis and evaluation of vital structural assets such as prestressed concrete bridges. It is crucial to develop theoretically consistent, user-friendly, and non-destructive methodologies that engineering professionals can employ to prevent and mitigate potential catastrophic outcomes during the service life of these bridges. This study provides a thorough review of the available testing methods employed over the years for prestressed concrete bridges and introduces a comprehensive framework for evaluating existing methods for residual prestress force assessment. Through a multi-criteria selection process, the three most feasible tests were designed and carried out on an existing 66-year-old balanced cantilever box girder bridge exposed to freezing temperatures that affected the instrumentation plan and test execution. Finally, predictive models compliant with standard codes were calibrated based on the experimental results and the life cycle loss of prestress forces was evaluated to assess relevant bounding intervals. Findings reveal limited on-site testing and discrepancies between calculated residual forces and predictions by standard codes. The saw cut method showed a 18% difference from the initial applied prestress according to the prestress protocol, suggesting the use of a cover meter and concrete modulus evaluation for improved accuracy. The strand cutting method resulted in a 14% difference, emphasizing the need for stress redistribution assessment. The second-order deflection method showed a 6% difference, indicating a focus on enhanced boundary conditions and thorough sensitivity analysis for future investigations.

Deterioration and imperfection of the ship structural components and its effects on the structural integrity: A review

Abstract The design of ship structural safety is crucial to ensure the ship’s survivability during the operation. Extensive research has been conducted on ship structural components, including box girders, stiffened panels, and plates, beyond the ideal conditions by considering the implication of manufacturing processes, vessel usage, and aging in the form of defects like cracks, corrosion, and imperfections, both locally and globally. Previous research has also explored various methodologies, conditions, and parameters to understand the impact of damages and imperfections on ship structure and strength. However, there is a significant need to bridge the gap in prior research to advance technology and ship structural strength analysis. A comprehensive benchmark study specifically focused on improving ship structural component needs, identifying differences and gaps among existing studies as challenging. This article thoroughly reviews ship structural components, such as box girders, stiffened panels, and plates, while examining the effects of structural defects like corrosion, cracks, and imperfections on ship structural integrity. It synthesizes the influence of various defect parameters, including crack length, angle, position, corrosion severity, pit corrosion, pit diameter, and pit models, using finite element modeling and experimental investigations, particularly emphasizing ship structural components. The comparative analysis of methods and parameters presented in this review will serve as a valuable reference for future investigations and studies related to ship structural strength and design. The article’s contribution is expected to enhance the understanding of ship structural strength, contributing to the sustainability and effectiveness of vessel design in the global maritime industry.