Steel Plate Girder Bridge Research Articles

Stress characteristics and cracking mechanism of web-to-stiffener weld in steel plate girder bridges under bending-shear action

The web-to-stiffener weld was subjected to bending-shear action, which was always neglected in previous research and affected the accuracy of fatigue evaluation. In this study, multi-scale FEMs (finite element models) of steel plate girder bridges were established to investigate the deformation characteristics, thus revealing the generating mechanism of bending-shear action. The fatigue comparison tests under bending-shear load and bending load were conducted to identify the cracking mechanism and its impact. The stress characteristics at the weld end were further explored through the structural mechanical model and verified by FEMs. The results show that the bending-shear action was caused by the inward and downward pulling by the stiffener on the web, and would lead to a premature transition from fatigue cracking to brittle fracture. The ratio of shear stress to normal stress was independent of load, inversely proportional to gap height, and positively related to web thickness, which could provide support for the accurate fatigue evaluation of web-to-stiffener weld.

Elastic-plastic flexural behavior of hybrid steel girder bridge considering welded residual stress

Hybrid steel girders use a section type that fully utilizes the strength performance of steels, which are widely used in steel plate girder bridges with multiple spans. In this paper, the distribution of the welded residual stress in hybrid I-shaped steel girders was investigated by the hole drilling test, and the unified model was analyzed and revised. Considering welded residual stress, the elastic and plastic design method for calculating the flexural capacity of hybrid I-shaped steel girders was put forward. Experiments and numerical simulations were conducted to analyze the elastic-plastic flexural behavior of the hybrid I-shaped steel girders using multi-scale models. The influence of welded residual stress, geometry of section, steel grade, and initial geometrical imperfections on the elastic-plastic flexural capacity of hybrid I-shaped steel girders were discussed through the parameter analysis adopting the dimensions commonly used in bridges. Analysis results show that the welded residual stress reduces the value of the elastic and plastic bending moments by almost 25% to 40% and 3%, respectively. The geometry of the section should be paid attention to clarify the value of the flexural capacity of the hybrid I-shaped steel girder. The width-to-thickness ratio limit of the flange should be adjusted according to the severity of initial geometrical imperfections.

Vibration characteristics and load-carrying capacity of multiple steel plate girder bridges with corroded girder ends

This study investigates the effects of corrosion on the vibrational characteristics and load-carrying capacity of steel plate girder bridge ends, which are extensively used in many bridges. First, eigenvalue and static analyses were performed using the finite element method, and the following main parameters were considered: the number of main girders, corrosion locations, and corrosion levels. The correlation between the results of the eigenvalue analysis and load-carrying capacity was examined; furthermore, to serve vibration-based health monitoring purposes, the selected parameters were investigated. The results indicated that the natural frequencies of the torsion-transverse coupling mode changed considerably as the corrosion ratio increased in the case of the corroded girder end and double-sided pin-bearing conditions. Additionally, a correlation between the natural frequency and load-carrying capacity was observed regardless of the number of main girders, indicating that the natural frequency and maximum load factor were related. In conclusion, the load-carrying capacity of corroded girder bridges can be estimated by measuring the transverse mode using an acceleration sensor installed on the upper flange and slab.

STUDY ON DETERIORATION OF THERMAL SPRAYED ALUMINUM COATING BY BRIDGE SURVEY

Since aluminum spraying has excellent corrosion resistance, it has been applied to many steel bridges in Japan since 2000s. However, in recent years, partial degradation has been observed in steel bridges with the thermal sprayed aluminum coating. This study aims to clarify the degradation mechanism of thermal sprayed aluminum coating. This study investigates thermal sprayed aluminum coating on-site on a steel plate girder bridge. In the bridge (constructed 17 years ago at estuary) investigation, the aluminum coating is generally in good condition, but the partial degradation is concentrated inside of the girder where the corrosion environment is severe. It was also confirmed that there were many corroded parts in the lower flange weld zone. Partial degradation occurs evenly throughout the bridge, but there is a tendency for more degradation to occur on the piers, where the corrosive environment is considered to be the most severe. A large amount of salinity was detected in the results of the attached salt content measurement near the corroded parts, and it is presumed that the salt content is a major factor in promoting the deterioration of the thermal sprayed aluminum coating.

Field Testing and Refined Load Rating of a Load-Posted Continuous Steel Girder Bridge

Load-posted bridges have potential effects on traffic, commerce, and emergency egress due to detours in routes between origins and destinations. Posted bridges can also be problematic for state departments of transportation from a management standpoint because they may call for more frequent maintenance, monitoring, and inspection. For these reasons, it is beneficial for states to minimize the number of load-posted bridges. This study investigates a continuous steel plate girder bridge superstructure and proposes a methodology for exploring the refined load rating of this bridge type in a safe manner through refined modeling and load testing. Load test results were used to examine live load distribution factors, and finite-element models were developed to refine load ratings. It was determined that the refined load-rating factors for the bridge are significantly higher than the currently posted limits, and therefore, the posting could be removed. The methodology presented in this paper can potentially be used to increase the load-rating factors for similar continuous steel girder bridges.

Buckling and Bearing Capacity Variation Caused by Local Corrosion at Support in Steel Bridge

The local corrosion of steel plate girder bridges at supports is a major issue affecting the safety. To clarify its effect on the buckling characteristics and bearing capacity, the static tests were carried out. The bearing capacities and local deformation were compared. The local buckling characteristics were refined by stress testing. To further investigate the effect mechanism of corrosion, the global finite element models (FEMs) of bridge were established. Separate corrosion of each component was considered. By comparing the strength and ultimate loads, the key member on bearing capacity reduction was specified. The influence of corrosion scope including the parameters of length, height, and depth on the bearing capacity was clarified. The results show the effect mechanisms of different-member corrosion on bearing capacity reduction were completely diverse. The web corrosion was the main cause of the bearing capacity reduction, which was the first to buckle. The relative position between corrosion scope and the support should also be considered during the evaluation of bearing capacity.

Data Normalization and Anomaly Detection in a Steel Plate-Girder Bridge Using LSTM

Modal properties are recognized as indicators reflecting structural condition in structural health monitoring (SHM). However, changing environmental and operational variables (EOVs) cause variability in the identified modal parameters and subsequently obscure damage effects. To address the issue caused by EOV-related variability, this study investigated the variability of modal frequencies in long-term SHM of a steel plate-girder bridge. A Bayesian fast Fourier transform (FFT) method was used for operational modal analysis in a probabilistic viewpoint. Bayesian linear regression (BLR) and Gaussian process regression (GPR) models were utilized to capture the variability in the identified most probable values (MPVs) of modal frequencies as temperature-driven models, and the limitation of these models for data normalization with latent EOVs is discussed. To overcome the interference of latent EOVs indirectly, a long short-term memory (LSTM) network was established to trace the variability as an autocorrelated process, with a traditional seasonal autoregressive integrated moving average (SARIMA) model as a benchmark. Finally, an anomaly detection method based on residuals of one-step-ahead predictions by LSTM was proposed associating with the Mann-Whitney U-test.

Cost comparison of steel plate girder and RCC girder bridge

Most of the part of nation especially city areas facing problem of traffic congestion due to unplanned increasing traffic intensity that is why requirement of elevated road access come into picture. The railway and road crossing is also required the elevated intersection. Most part of the country having superstructure of pre-stressed or RCC structure being heavy in weight creation expensive cost of sub-structure and foundation as well as bearing. A study has been conducted regarding the cost comparison of steel plate Girder Bridge and Reinforced Concrete Girder Bridge and found that steel plate girder is a sustainable option as being light in weight and are more efficient in compression and tension both.

Evaluation and Load Rating of a Steel Girder In-Span Hinge Connection

Continuous steel plate girder bridges often use intermediate expansion joints located at in-span hinges to divide the superstructure into individual units with shorter expansion lengths. One common type of in-span hinge is often termed a “shiplap joint.” This type of joint is located away from piers near the moment inflection point of the span, maximizing girder efficiency. It consists of a cantilevered portion of the superstructure supporting a suspended portion of the latter on bearings placed on dapped portions of the steel plate girders. Few references are available for the evaluation and load rating of shiplap in-span hinges used in steel girder bridges. In this study, the strength and stability of a typical shiplap hinge connection is evaluated using two methodologies: a 3D finite element model including a detailed mesh of the connection; and a proposed simplified methodology based on design equations. Load ratings of the connections based on these methodologies are compared. The proposed approach allows for a conservative assessment of the hinge without the need for a detailed finite element model.

Lateral Resistance Requirement of Girder-Sleeper Fastener for CWR Track on an Open-Deck Steel Plate Girder Bridge

For an open-deck steel plate girder railway bridge with rail joints, frequent damage to the bridge members and a high level of noise and vibration occur. By installing continuous welded rail (CWR) to the bridge, it is possible to reduce the noise and impact force of the bridge. However, current girder–sleeper fasteners have low lateral resistance in nature and track buckling can occur when CWR is used on such a bridge. Therefore, a new girder-sleeper fastener with proper lateral resistance to prevent CWR track buckling is needed. In this study, the lateral resistance requirements of a girder-sleeper fastener are investigated through a series of finite element (FE) analyses and parametric study. The effect of peak lateral resistance of the fastener, curve radius, girder length, and lateral displacement of girder are examined. From the analysis results, the peak lateral resistance criterion of the girder–sleeper fastener is proposed for the design of a new fastener for CWR tracks on an open-deck steel plate girder bridge.

Seismic performance of a two-span steel girder bridge with ABC connections

This paper presents the discussion and results from the first shake table test of a steel girder bridge system constructed using accelerated bridge construction (ABC) techniques. The bridge model was tested at the multi-shake table testing facility at the University of Nevada, Reno. The objective of this study was to evaluate the seismic performance of a bridge system incorporating six types of ABC connections under strong bidirectional earthquake shaking. The test model was a 0.35-scale, two-span steel plate-girder bridge with seat type abutments. The model was subjected to eight earthquake motions adopted from the 1994 Northridge-Sylmar ground motion applied with increasing amplitudes. The paper presents the global and local response of the bridge model with focus on ABC connections. Moreover, the paper provides a first hand demonstration of a full ABC bridge system seismic performance, which was found to be satisfactory and adequate to adopt the utilized ABC connections for future projects.

Detection and Evaluation of the Bearing Capacity of Railway Steel Plate Girder Bridges

To ensure the safe operation of existing railway bridges, it is necessary to conduct comprehensive inspections of their bearing capacity and actual working conditions on a regular basis. In this paper, taking the 2# steel plate girder bridge on Qinglv Branch Heihe as an example, the appearance inspection, pier and abutment strength test, static load test and dynamic load test were carried out on this steel plate girder bridge, and the content and method of the comprehensive test of the steel plate girder bridge were explained; Based on the test results, the working condition of the bridge was evaluated, hoping to provide reference and reference for other similar bridge type inspection and reinforcement work.

Modelling a steel-plate girder bridge strengthened with carbon-fibre reinforced polymer

This paper reports on a numerical study into the crack-dependent behaviour of a steel-plate girder bridge strengthened with carbon-fibre-reinforced polymer sheets. Progressive cracking, which represented fatigue-induced damage, was simulated from up to 10% of the girder depth. Finite-element analysis was used to evaluate the performance of the control, damaged and strengthened cases subject to standard US highway fatigue loading. The efficacy of polymer strengthening was also examined from a strength perspective, using the load factor rating method and the load and resistance factor rating method. Localised fatigue cracking caused a stress concentration along the girder and its progression rate was related to the degree of web fracture. The damage of the tensile flange was more influential in reducing the flexural capacity of the girder relative to damage of the web. The strengthening decreased the stress ranges, thereby increasing the fatigue life of the girder, and enhanced the maximum average daily traffic capacity. Reliability modelling indicated a transition in failure rates before and after 3% cracking in the girder, supporting the extended functional time resulting from strengthening.

STRENGTH RECOVERY OF STEEL BRIDGES WITH CORROSION NEAR BEARINGS

A lot of steel plate girder bridges were erected during the rapid growth in the 1960s in Japan. Currently, the condition of those aging bridges has become marked and a problem in society since over 50 years have passed. Particularly, the corrosion-induced deterioration and damage in railway steel plate girder bridges, which have an open deck, is becoming prominent. Despite that, the evaluations of residual strengths and the strengthening methods of corroded bridges are not always enough. Therefore, firstly, this paper shows analytical-based evaluation results that explain how the residual shear capacities of plate girders, having corrosion near bearings, depend on the condition of the corroded surface, such as a vertical stiffener or a web. The results show the fracture mode as buckling changes as well as the residual shear capacity, according to the degree and form of corrosion. Next, this study proposes a reliable reinforcement measure to recovery the shear capacity by applying said evaluation results and analytical models. Finally, the shear capacity could be improved tremendously by simple attachments as reinforced members.

Estimating the Dynamic Behavior of Highway Steel Plate Girder Bridges Using Real-Time Strain Measurements

Structural health monitoring (SHM) techniques are used to assess the behavior of structures during or after construction. The high cost of sensors is the main reason for the limited use of the SHM techniques. The present study investigates the dynamic behavior (dynamic acceleration, semi-static displacement, frequency and damping ratio) of highway steel plate girder bridges using strain measurements. The double filtration and polynomial prediction methods are used to estimate the dynamic behavior of the bridge using real-time strain measurements. To verify the accuracy of the developed method, the field monitoring measurements of the WonHyo bridge is used. The bridge behavior under different truck speeds and weights is observed and evaluated. The displacement and acceleration measurements are used to examine the results of the proposed method. The results of this study demonstrate that the strain measurements can be used to obtain an accurate semi-static displacement and dominant frequency content of the bridge. The accuracy of the developed model for the semi-static and dynamic behaviors is 99% and 69%, respectively.

New design rules for plate girders curved in plan

Many steel plate girder bridges today are curved in plan. This is because it is now relatively inexpensive to construct bridges with continuous plan curvature, which is more aesthetic than the traditional series of straight spans kinked at supports, and because many bridges are now built in congested urban areas where complex curved plan alignments are required to thread new infrastructure past the existing. However, design rules have not caught up with this fabrication trend. The design of continuously curved steel plate girder bridges is typically more complex than that for equivalent straight ones. The plan curvature both induces additional stresses in the webs and flanges, reducing overall bending strength, and changes the shear behaviour and resistance of the webs. This paper considers typical steel–concrete composite multi-girder decks with plan curvature and uses the results of an extensive finite-element parametric study to propose new design rules based on modifications to the existing Eurocode rules for straight girders so there is a consistent approach provided for the design of plated girders for all curvatures, including none.

Experimental Estimation of the Impact Factor of an Open Deck Steel Plate Girder Bridge by Considering the Train Velocity

Experimental Estimation of the Impact Factor of an Open Deck Steel Plate Girder Bridge by Considering the Train Velocity

Determining the location of sensors for seismic damage detection in steel girder bridges with elastomeric bearings

In planning a bridge health monitoring with minimum sensors for long-term monitoring, it is necessary to accurately predict the bridge behavior including its nonlinearity and identify the damaged bridge components when a strong earthquake strikes. This article presents a methodology for the selection of sensors and their arrangement for detecting seismic damage in an in-service steel plate girder bridge system. In this study, a detailed span-based model was developed for the finite element simulation including the effect of the rubber bearing and piers, and the damage control by the side blocks. The finite element dynamic simulation was carried out with input earthquake acceleration to investigate the seismic behavior and grasp the damageable parts during an earthquake. Based on the results of finite element dynamic simulation, a fault tree analysis was carried out to reveal more about the bridge behavior, the failure modes, and the occurrence of damage. It was found that the side block, the bearing stiffener, and the horizontal bracing on the fixed side of the bridge are most important to be monitored for the evaluation of soundness of a plate girder bridge immediately after an earthquake. Finally, a sensor arrangement for the bridge was proposed based on the analysis results.

An evaluation of dew condensation on steel plate girder bridges

An evaluation of dew condensation on steel plate girder bridges

Pretest analysis of shake table response of a two-span steel girder bridge incorporating accelerated bridge construction connections

This paper presents pretest analysis of a shake table test model of a 0.35-scale, two-span, steel plate girder bridge. The objective of pretest analysis was to obtain an insight on the seismic response of the bridge model during the shake table tests. The bridge included seat type abutments, full-depth precast deck panels, and a two-column bent in which columns were pinned to the footing and integral with superstructure. Six accelerated bridge construction connections were incorporated in the bridge model. An analytical model was developed in OpenSees and was subjected to ten input bi-directional earthquake motions including near-fault and far-field records. The overall seismic response of the bridge was satisfactory for all the earthquake records at 100%, 150%, and 200% design level. All connections and capacity-protected components remained elastic, and the average ductility capacity surpassed the ductility demand even at 200% design level. Using experimental fragility curves developed for RC bridge columns, it was predicted that there was a probability of 45% that columns would undergo the imminent failure in the last run and a probability of 30% for their failure.