Highway Bridge Decks Research Articles

Friction stir welded joints in aluminum highway bridge decks: a quality control framework

Friction stir welding (FSW) has shown considerable promise for highway aluminum bridge deck fabrication but lacks specific quality control guidelines for fit-up defects. This study conducts a performance-based (PB) quality control assessment of butt-lap FSW joints for highway bridge decks. Five FSW conditions were simulated, including a standard control welding condition, fit-up defects (gaps and tool offset), and a welding tool’s rotational direction inversion from the standard condition. A rigorous prequalification process established acceptable tolerance levels for fit-up defects: a 3 mm positive offset, a 1.5 mm negative offset, and a 1.5 mm gap. Subsequently, specimens from real aluminium deck extrusions, incorporating the various welding conditions were subjected to fatigue testing. Results showed that the fatigue strength and failure mode were primarily influenced by the weld root microstructure. The FSW tool’s rotational direction significantly influenced fatigue strength due to its impact on the nucleation of the hooking defect in the weld root area, while the impact of fit-up defects on fatigue strength was comparatively lesser. Furthermore, finite element analysis examined the impact of the geometrical features of the root microstructure and the direction of the initial crack propagation on the stress intensity factor range. These findings have practical implications for setting tolerance levels for fit-up defects in aluminum butt-lap FSW joints and optimizing of the quality and fatigue strength of butt-lap FSW joints.

Simulation Based Study Of Ground Mobile Robots For Inspection And Control Of The Bridge Assembly Process

Nowadays, the inspection of bridges poses a significant challenge for safeguarding critical infrastructures. Recent advancements have seen the integration of robots to replace human personnel in hazardous tasks. These robots, whether operating autonomously or through tele-operation, play a crucial role in monitoring structures and infrastructure, ensuring secure access to areas such as manholes on decks and box girder bridges. Specifically designed for environments deemed dangerous, difficult, or inaccessible to humans, ground mobile robots equipped with appropriate sensors are increasingly deployed for inspection purposes. This paper addresses simulation tests conducted by a hybrid mobile robot. Its compact design and maneuverability enable it to navigate through obstacles, making it suitable for inspecting railway or highway bridge decks as well as confined spaces within box girder bridges. The study includes a survey of existing bridges highlighting key issues to be addressed and presents simulation results for the hybrid rover, which has been developed and equipped with sensors tailored to fulfill inspection tasks within a selected case study.

Analysis of heat transfer and prediction of preheating time of snow-melting on a highway T-beam bridge deck

Electrical heating is an innovative method of preventing icing of bridge decks during winter. Turning on the heating system before snowfall to prevent the icing of the bridge deck is more advantageous than melting already-formed ice. This article analyzes the heat-transfer performance of a bridge deck with heating cables during preheating before snowfall and predicts the preheating time of the bridge deck. Firstly, the temperature rise law and the state of the bridge deck with heating cables were studied through field experiments. Subsequently, a numerical model was developed. The effects of four factors on the heat-transfer performance of the bridge deck were analyzed. Finally, a bridge deck preheating-time model was established based on a multilayer perceptron regressor. This study enriches the application of neural networks and numerical simulations in preventing ice formation using the electrical heating method and is important for optimizing the heating system scheme and saving energy.

Wind field characteristics of asymmetric bridge deck for a road-rail same-story bridge

The purpose of this study is to investigate the flow field characteristics of the road-rail same-story asymmetric bridge deck and the influence of the asymmetric arrangement of the bridge deck on the flow field of the main girders. Numerical simulation tests were conducted on this bridge to analyze the distribution characteristics of the flow field near the main girder, as well as the aerodynamic characteristics of the railway bridge deck and highway bridge deck under different wind speeds and directions. The results indicate that the wind speed has less influence on the flow field distribution and aerodynamic characteristics of the road-rail same-story asymmetric bridge deck, but the incoming flow direction has a significant impact on its flow field characteristics. Compared to the railway bridge deck, during the reattachment position of the airflow, the highway bridge deck moves toward the windward side, and the volume of the separation bubble has been reduced, thus improving the effect on the negative pressure area of the railway bridge deck. The road-rail same-story asymmetric bridge deck has different aerodynamic interference characteristics for different wind speeds and different wind directions.

Study of Rail Structure Interaction on Double-Decker integrated bridge with Metro and Highway Structure

In the metro rail system, Long Welded Rails (LWR) have been used for less maintenance, smooth & safe ride at higher speeds. The arrangement of connecting rail and deck system causes an interaction effect in force transfer. The study of this effect in the structure is Rail Structure Interaction (RSI) analysis. In this study, the behavior of double-decker integrated structure, rail stresses and relative deformation are studied due to the bending behavior of the deck, bearing articulation & support stiffness with the proposed geometrical arrangement of the bridge and applicable loading as per standards. The effect of RSI analysis and limitations of additional stresses are referred with the guidance of UIC standards & RDSO guidelines. The double-decker elevated viaduct structure is proposed with a first level highway deck carrying highway loading and second level metro system carrying metro loading. In highway bridge deck, the decks are proposed with four span continuous to avoid discomfort due to more number of expansion joints and thereby provide smooth riding for passengers. The effect of RSI is studied in this paper by considering the above complexity of two-level superstructure with a different type of superstructure at the metro level due to the track requirement like U girder deck system at each track, I girder deck system as a single deck for both the tracks at the cross over / pocket track locations and I girder deck system at highway level with deck continuity. A finite element analysis is performed using the analytical tool MIDAS CIVIL software to study the interaction mechanism for this double-decker bridge structure. For this study, rail and deck (unballasted) are linked with a multilinear elastic spring as recommended in UIC 774-3R and other boundary conditions as per IRS & IRC standards. This paper discusses the behavior of structure from the results of the rail stresses and forces to the substructure due to thermal and live load effects at both level Metro Rail system and Highway Road systems.

Generative adversarial network for predicting visible deterioration and NDE condition maps in highway bridge decks

Bridge decks tend to degrade faster than other bridge components due to environment exposure and vehicular loading. Periodic degradation monitoring is needed for timely rehabilitation measures and development of service life models in bridge decks. Surface degradation are identified through visual inspection (VI) and post-processing of high-definition imagery. Although VI is the primary NDE method employed by most transportation authorities, many anomalies (e.g., cracking, corrosion, and delamination) remain hidden under the surface until deteriorations have grown large enough to surface (e.g., spalling). Subsurface degradation is best identified through other forms of non-destructive evaluation (NDE). Inferences can be made between the various NDE methods, as the mechanisms behind the damages sensed by each method are shared. For instance, condition map from an NDE method may infer future visible deterioration, as well as condition maps for other NDE methods. In this paper, a deep learning approach based in a conditional generative adversarial network is presented for modeling of plausible visible deterioration and NDE condition maps. Two applications are explored: (i) visualization of plausible future deterioration based on current NDE condition map, and (ii) visualization of condition maps for NDE methods from other NDE methods. Field and experimental data from the BEAST facility at Rutgers University are used to develop the training databases for each application.

Fatigue behaviour of butt-lap friction stir welded joints used with aluminum bridge decks

This paper presents the results of experimental tests and a numerical investigation of the fatigue behavior of butt-lap friction stir welded (FSW) joints used in highway bridge decks made from aluminum extrusions. A large-scale fatigue experiment was designed to initiate fatigue failure in the butt-lap FS welds joining two full-scale aluminum extrusions used for highway bridge decks. Ten fatigue tests were carried out on an MTS servo-hydraulic press. Test results were used to analyze the fatigue failure mode of this unique joint type and to derive the S-N curve useful for the characterization and design of fatigue-sensitive details. The fatigue data was assessed using the effective notch stress (ENS) approach as recommended by the International Institute of Welding (IIW). Results show that the IIW design ENS IIW FAT-71 curve derived from fatigue tests on fusion-welded joints is conservative in assessing the fatigue behavior of butt-lap friction stir welded (FSW) joints, especially in the high cycle regime.

Influence of vehicular movement on the seismic response and fragility of highway bridge structures

Recognising the criticality of highway bridges for the socio-economic development of a nation, multiple researchers have endeavoured towards quantifying the seismic fragility of these key infrastructure elements. Given the present boom in urbanisation, however, there may also be an appreciable likelihood of vehicle presence on the highway bridge deck during an earthquake event. This study focuses on the impact assessment of vehicle-bridge-interaction (VBI) on the seismic fragility of highway bridges by explicitly accounting for vehicular movement atop the bridge deck during seismic shaking. Addressing existing drawbacks in literature that typically adopts a simplified modelling strategy and static vehicle placement, this paper considers different types of moving vehicles (modelled as mass-spring-dashpot system analogies) for VBI assessment through a novel algorithm. The proposed framework also accounts for uncertainties involved in the moving vehicle analysis, pertaining to vehicle characteristics and driver’s perception of the earthquake. The framework is demonstrated on representative multi-span continuous steel girder bridges located in Central and Southeastern United States. A comparative assessment of hysteretic response of bridge components and seismic fragility curves indicate a considerable influence of vehicular movement on bridge damage, signifying the importance of considering moving VBI effects for thorough seismic assessment of highway bridge structures.

Shear behavior of multi-axial fiber reinforced composite sandwich structures with pultruded profile core

In this paper, a new sandwich structures using multi-axial glass fiber reinforced polymer (GFRP) as face sheets and webs while pultruded profile as core was proposed, which intended to be used in engineering fields such as trestle board, bridge deck, emergency road deck. The shear behavior of the multi-axial fiber reinforced composite sandwich structures with pultruded profile core was investigated, and the failure modes, load-deflection behavior and load-strain relationships were obtained and compared under three points bending test. The results showed that all the sandwich structures had obvious omen before failure, and the final failure modes and shear bearing capacities of the sandwich structures varied with web thickness, face sheet thickness and the type of fiber cloth. Among them, increasing the thickness of the surface layer of sandwich structure is the most obvious way to improve the shear capacity, which can increase the shear capacity by more than 40 %. Formulas to calculate the stiffness, the deflection and the ultimate bearing capacity were derived and proved appropriate. Meanwhile, the proposed pultruded profile sandwich structure was proved can be used as highway bridge deck.

Defect Point Location Method of Civil Bridge Based on Internet of Things Wireless Communication

With the growth of the country’s comprehensive strength, China’s road and bridge traffic is also growing rapidly. Therefore, the maintenance of highway bridge pavement has become extremely important. The main manifestation of highway bridge deck diseases is bridge deck cracks. If the bridge deck cracks are found in the early stage of damage and solved in time, it will undoubtedly greatly reduce the maintenance cost and care and ensure that the road can be driven safely. At present, the detection of highway bridge defects is mainly based on human vision, but this kind of artificial visual inspection is difficult to complete efficiently. The purpose of the article was to study image recognition techniques and measure the surface damage to bridge superstructures. It has also developed an intelligent software system that can measure and identify cracks under bridges. Aiming at the compatibility problem of wireless communication front end caused by the difference in wireless communication protocols, this study designs a high-applicability front-end control interface for wireless communication. After testing, data can be sent and received when the I/O mode rate drops to 10 Kbps. This method is severely limited and is not suitable for IoT applications with low power consumption and low frequency. It uses the SPI interface for communication and can send and receive normally at different rates, with an upper limit of 8 Mbps. This method consumes a little more pins, but the clock signal is stable, and the transmission performance can meet the needs of most applications.

Development of Applicability of Distribution Factor for Single Cell Box Girder Bridges by Modifying Bakht and Mufti Method

Live load distribution factors for simply supported single cell box girder by manual method has been studied. The distribution factor allows the designer to consider the transverse effect of wheel loads in determining the shear and moments of each beam for live load. The increased need of transporting very heavy loads by road haulage has given rise to the need for an easily applied and accurate method of calculating the division of loads between the main girders of highway bridge decks. The bridge is loaded with IRC 70 R and Class A loading so as to obtain maximum bending moment. Bakht and Mufti is close representation of semi-continuum idealization to obtain distribution factors for slab on girder bridges where shear deformation or more correctly cell distortion is neglected. An attempt is made to obtain distribution factor for single cell box girders by modifying the formula of Bakht and Mufti method with Cusens and Pama formula to consider distortional effects. Results are compared with spine beam method using Midas Civil Software which shows good agreement between both the methods.

Heterogeneity-Based Survival Analysis of NBI Condition Ratings for Concrete Highway Bridge Decks in Oregon by Condition Group

AbstractThis study applied a heterogeneity-based survival analysis to determine significant contributing factors to a bridge deck’s time-in-condition rating (TICR) by condition rating (CR) group: h...

Moving-wheel fatigue durability of cantilever bridge deck slab strengthened with high-modulus CFRP rods

Reinforced concrete (RC) slabs of highway bridge decks are gradually deteriorated due to the traffic vehicle wheel-loading. Fatigue is one of a number of possible causes for the deterioration. Cantilever RC slabs of the bridge are also damaged by fatigue loading. To increase the fatigue durability of the bridge deck slab, the near-surface mounted (NSM) technique is used with carbon fiber reinforced polymer (CFRP) rods embedded in the RC slab as an effective strengthening method. This study presents the fatigue characteristics of cantilever RC slabs strengthened with CFRP rods with a high-modulus of elasticity. A cantilever RC slab specimen with embedded CFRP rods with high moduli was constructed on a moving-wheel load testing machine and tested for approximately 11 months. The slab had a minimum thickness of 160 mm (as stipulated by the Japanese design code), and the minimum number of steel reinforcements was embedded to ensure (negative) flexural failure of the RC slab where CFRP rods were not used. During the test, the CFRP strengthened slab specimen was subjected to a negative bending moment from repeated moving-wheel loads. Very limited experimental data are available for the evaluation of the structural behavior of cantilever bridge decks subjected to wheel loads. Therefore, the moving-wheel fatigue experiment of the cantilever RC slab with NSM CFRP rods would be useful information for strengthening. The moving-wheel loading test confirmed the increase in fatigue durability of the CFRP strengthened slab as the slab specimen endured approximately 3.56 million equivalent-cycles at an initial load of 60 kN, which was 32% higher than the designed service load. The experimental investigation revealed that the ultimate failure of the cantilever slab was punching shear failure attributed to the rupture of the CFRP rods.

Influence on Highway Bridge Deck System Reconstruction by Train-passing-railway Induced Vibration of the Nanjing Yangtze River Bridge

Influence on Highway Bridge Deck System Reconstruction by Train-passing-railway Induced Vibration of the Nanjing Yangtze River Bridge

Implementation of video motion magnification technique for non-contact operational modal analysis of light poles

Damages on lights and utility poles mounted on the elevated highway or railway bridges were observed in the past several large earthquakes. The damages could have serious consequences to public safety, travelling vehicles or trains, and nearby properties. A previous study shows that the damages were caused by buckling and yielding of the pole due to excessive response amplification during large earthquake. Such amplification occurs when the bridge's natural frequency is close to the light pole's fundamental frequency. An investigation of the seismic performance of existing light pole mounted on elevated highway bridges is needed to avoid the response amplification. This includes the identification of the light pole's natural frequency and damping ratio. Vibration testing of the light pole using conventional contact sensors individually would require enormous effort and is time-consuming. Moreover, such vibration testing on a highway bridge deck would require traffic disruption to provide access. Video camera-based non-contact vision sensing is seen as a promising alternative to the conventional contact sensors for this purpose. The objective of this paper is to explore the use of non-contact vision sensing for operational modal analysis of light pole on highway viaduct. The phase-based video motion magnification method is implemented to obtain the light pole response in an ambient condition. Using this method, small and invisible displacement is magnified for a certain range of frequency of interest. Based on the magnified video frames, structural displacement is extracted using the image processing technique. The natural frequency and damping ratio of the light pole are estimated using the random decrement technique. The method is verified in a laboratory-scale experiment and implemented to practical field measurements of a light pole on a highway viaduct in Kanagawa, Japan. The results are compared with measurement by Laser Doppler Vibrometer. Both experiments suggest that the method could effectively obtain the natural frequency and damping ratio of the structures under the ambient condition where vibration amplitudes are very small and invisible with reasonable accuracy.

土木学会 鋼構造シリーズ 35「道路橋床版の維持管理マニュアル2020」の概要

土木学会鋼構造委員会では，鋼道路橋の床版について1997年より小委員会を設置し，継続的に調査研究している。2017年からの道路橋床版の点検診断の高度化と長寿命化技術に関する小委員会では，その研究成果の一つとして2020年10月に，「道路橋床版の維持管理マニュアル2020」を鋼構造シリーズ35として出版した。道路橋において最も劣化の激しい部材の一つである床版の維持管理に特化したマニュアルであり，その構成は，道路橋床版の損傷と劣化，点検・調査方法，劣化進行過程の評価，対策工法選定，維持管理事例である。マニュアルの概要とともに主な改訂内容としてマニュアルの活用方法と点検調査技術の活用について解説している。

Prediction of Remaining Life for Bridge Decks Considering Deterioration Factors and Propose of Prioritization Process for Bridge Deck Maintenance

Aged highway bridges have become substantially prevalent in recent years. Moreover, combined deterioration, caused by using deicing agents in winter, has led to increased bridge maintenance costs. Accordingly, to extend the service life of bridge decks, this study utilized actual inspection data and major deterioration factors to derive the remaining service life of bridge decks. Based on this study, the following three factors are selected: deicing agent exposure grade, pavement condition state, and surface improvement status. Performance degradation curves were derived for 11 cases that considered the representative three deterioration factors, and the performance degradation of decks was examined for each deterioration factor. Additionally, a process to determine maintenance priorities, using the current condition of highway bridges and the deterioration factors of individual bridges, was proposed. The maintenance demand was predicted based on the end of deck life, which indicated that the demand for deck replacement will sharply increase in 15 years, and that the decks of more than 2000 bridges will reach the end of life in 40 years. Furthermore, this paper proposes a process for prioritizing the maintenance of approximately 9000 highway bridge decks. By applying the prioritization process for bridge deck maintenance to the bridge deck, not only can the life of the bridge deck be extended, but also environmental pollution can be minimized. Additionally, an optimizing design for bridge decks, by considering the remaining life and deterioration factors, can be possible. Therefore, it is expected that the sustainability of the bridge deck can be accomplished.

Survival Analysis of Concrete Highway Bridge Decks in Oregon Utilizing LASSO and Stepwise-Variable Selection

Abstract This research studied the relationship between Oregon national bridge inventory (NBI) data as well as additional design/detailing variables and concrete highway bridge deck performance. Co...

Incorporating the Effects of Climate Change into Bridge Deterioration Modeling: The Case of Slab-on-Girder Highway Bridge Deck Designs across Canada

AbstractClimate change is expected to impact both the operational and structural performance of infrastructure such as buildings, roads, and bridges. However, infrastructure design guides widely re...

Partial Composite-Action and Durability Assessment of Slab-on-Girder Highway Bridge Decks in Negative Bending Using Long-Term Structural Monitoring Data

AbstractThis paper uses long-term bridge monitoring data to quantitatively assess the composite action exhibited in slab-on-girder highway bridges and investigates the potential relationship betwee...