Construction Management and Installation Quality Control Strategy of Steel Bridges

At present,China’s bridges are mostly made of concrete,which contain a large amount of cement,sand and gravel and other materials,which can easily cause environmental pollution.At the same time,China’s total steel production continues to rank first in the world.The construction and development of steel bridges have sufficient basic support.At the same time,steel is more environmental-friendly than concrete,with higher strength,lower weight,and can reduce construction waste significantly,so the development of steel bridges has been on the rise.To optimize the application effect of steel structure bridges,it is necessary to analyze the construction management and installation quality control strategies of steel bridges for reference.

Dynamic Response Impact of Vehicle Braking on Simply Supported Beam Bridges with Corrugated Steel Webs Based on Vehicle-Bridge Coupled Vibration Analysis

A novel approach for analyzing coupled vibrations between vehicles and bridges is presented,taking into account spatiotemporal effects and mechanical phenomena resulting fromvehicle braking.Efficient modeling and solution of bridge vibrations induced by vehicle deceleration are realized using this method.The method’s validity and reliability are substantiated through numerical examples.A simply supported beam bridge with a corrugated steel web is taken as an example and the effects of parameters such as the initial vehicle speed,braking acceleration,braking location,and road surface roughness on the mid-span displacement and impact factor of the bridge are analyzed.The results show that vehicle braking significantly amplifies mid-span displacement and impact factor responses in comparison to uniform vehicular motion across the bridge.Notably,the influence of wheelto-bridge friction forces is of particular significance and cannot be overlooked.When the vehicle initiates braking near the middle of the span,both the mid-span displacement and impact factor of the bridge exhibit substantial increases,further escalating with higher braking acceleration.Under favorable road surface conditions,the midspan displacement and the impact factor during vehicle braking may exceed the design values stipulated by codes.It is important to note that road surface roughness exerts a more pronounced effect on the impact factor of the bridge in comparison to the effects of vehicle braking.

Numerical Simulation Analysis of Welded Joints in Arch Ribs of Large Span Steel Pipe Arch Bridges

In order to study the residual stress distribution law of welded joints of arch ribs of large-span steel pipe concrete arch bridges,numerical simulation of temperature,stress and strain fields based on ABAQUS for welded joints of arch-ribbed steel tubes using 7-,8-and 9-layer welds is carried out and its accuracy is demonstrated.The steel pipe welding temperature changes,residual stress distribution,different processes residual stress changes in the law,the prediction of post-weld residual stress distribution and deformation are studied in this paper.The results show that the temperature field values and test results are more consistent with the accuracy of numerical simulation of welding,the welding process is mainly in the form of heat transfer;Residual high stresses are predominantly distributed in the Fusion zone(FZ)and Heat-affected zone(HAZ),with residual stress levels tending to decrease from the center of the weld along the axial path,the maximum stress appears in the FZ and HAZ junction;The number of welding layers has an effect on the residual stress distribution,the number of welding layers increases,the residual stress tends to decrease,while the FZ and HAZ high stress area range shrinks;Increasing the number of plies will increase the amount of residual distortion.

Defect Inspection Technology for Steel Truss Suspension Bridges

Steel truss suspension bridges are prone to developing defects after prolonged use.These defects may include corrosion of the main cable or the steel truss.To ensure the normal and safe functioning of the suspension bridge,it is necessary to inspect for defects promptly,understand the cause of the defect,and locate it through the use of inspection technology.By promptly addressing defects,the suspension bridge’s safety can be ensured.The author has analyzed the common defects and causes of steel truss suspension bridges and proposed specific inspection technologies.This research is intended to aid in the timely discovery of steel truss suspension bridge defects.

Fatigue Performance Evaluation for Welded Details in Orthotropic Steel Deck Bridges Using Multi-Scale Finite Element Method

In order to study the fatigue properties of rib-to-deck welded connection and rib-to-rib welded connection in orthotropic steel bridge decks,a multi-scale finite element model was set up to analyze the stress distribution characteristics and the load test was conducted on the Taizhou Yangtze River Bridge.Comparing the vehicle test results with the muli-scale finite element model results to verify the accuracy of the finite element simulation for the stress response of two welded details.The results indicated that The stress at the rib-to-deck welded connection and the rib-to-rib welded connection are the bending stress and the membrane stress,respectively;the stress response of the two welded connection has strong local characteristics;the lateral stress influence line of the two welded connection is relatively short and the length of the lateral stress influence line is greatly affected by the longitudinal ribs;increasing the thickness of the roof and longitudinal ribs can reduce the stress response and improve the stress performance of the heavy lanes.For the two welded details,the fatigue damage increment of the ordinary lane is greater than the heavy lane.The thickened roof and longitudinal ribs at the position of the heavy lane still cannot balance the fatigue damage caused by the heavy truck.Therefore,it is necessary to strictly control the fatigue effect of overloaded vehicles on steel box girders.

Seismic behavior of steel tubular bridge columns equipped with low-yield-point steel plates in the root replaceable pier

To enable rapid recovery of a steel bridge column after an earthquake,a novel tubular-section steel bridge column equipped with low-yield-point(LYP)steel tubular plates in the root replaceable pier is proposed.For the purpose of discussing the seismic behavior of the novel steel bridge column,quasi-static tests and finite element simulation analyses of the specimens were carried out.The effects of parameters such as the axial compression ratio,eccentricity,and thickness and material strength of the tubular plate in the energy-dissipating zone are discussed.Experimental results from seven specimens that were subjected to four failure modes are presented.The damage to the quasi-static specimens is localized to the replaceable energy-dissipating pier.The seismic behavior of the novel steel bridge columns is significantly influenced by the axial compression ratio and eccentricity of specimens.Numerical results show that the high stress area of the specimens is mainly concentrated in the connection zone between the LYP steel tubular plate and the bottom steel plate,which is consistent with the position of the quasi-static specimen when it was prone to fracture.Finally,a calculation formula is proposed to facilitate the capacity prediction of this new steel tubular bridge column under repeated loading.

Research on heavy-haul adaptive technology and strengthening measures for existing railway steel bridge

Purpose–This research addresses the diverse characteristics of existing railway steel bridges in China,including variations in construction age,design standards,structural types,manufacturing processes,materials and service conditions.It also focuses on prominent defects and challenges related to heavy transportation conditions,particularly low live haul reserves and severe fatigue problems.Design/methodology/approach–The study encompasses three key aspects:(1)Adaptability assessment:It begins with assessing the suitability of existing railway steel bridges for heavy-haul operations through comprehensive analyses,experiments and engineering applications.(2)Strengthening:To combat frequent crack defects in the vertical stiffener end structure of girder webs,fatigue performance tests and reinforcement scheme experiments were conducted.These experiments included the development of a hot-spot stress S-N curve for this structure,validating the effectiveness of methods like crack stop holes,ultrasonic hammering and flange angle steel.(3)Service life extension:Research on the cruciform welded joint structure(non-fusion transfer type)focused on fatigue performance over the long life cycle.This led to the establishment of a fatigue S-N curve,enhancing Chinese design codes.Findings–The research achieved several significant outcomes:(1)Successful implementation of strengthening and retrofitting measures on a 64-m single-span double-track railway steel truss girder on an existing heavy-duty line.(2)Post-reinforcement,a substantial 26%to 32%reduction in live haul stress on bridge members was achieved.(3)The strengthening and retrofitting efforts met design expectations,enabling the bridge to accommodate vehicles with a 30-ton axle haul on the railway line.Originality/value–This research systematically tackles challenges and defects associated with Chinese existing railway steel bridges,providing valuable insights into adaptability assessment,strengthening techniques and service life extension methods.Furthermore,the development of fatigue S-N curves and the successful implementation of bridge enhancements have practical implications for improving the resilience and operational capacity of railway steel bridges in China.

A systematic review of steel bridge deck pavement in China

As an important part of steel bridge deck,the engineering quality and service condition of steel bridge deck pavement(SBDP)directly affects the capacity and operational efficiency of the bridge.This paper reviews the history of the development of SBDP in China over the past 20 years from the exploration stage,rapid development stage and prosperity stage.The development and application of SBDP at different stages are discussed in terms of materials,structure,design,performance evaluation,maintenance and rehabilitation,respectively.The advantages and disadvantages of different pavement materials and structures,and the application of different research methods are summarized.The review shows that the improvement of pavement materials and structures and the development of new materials should be further studied on the multi-scale to enhance the durability of pavement materials,so as to extend the service life of pavements.The design method of SBDP related to the synergistic effect of vehicle,pavement and bridge should be established,and the design concept and method standard of rigid base pavement structure should be improved and formulate a complete design standard.In addition,multi-disease intelligent identification system and equipment should be studied to track the entire course of disease development in real time.And it is necessary to develop appropriate algorithms to select and classify the complex data of disease and maintenance history.

Fatigue Crack Propagation Analysis of Orthotropic Steel Bridge with Crack Tip Elastoplastic Consideration

Due to the complex structure and dense weld of the orthotropic steel bridge deck(OSBD),fatigue cracks are prone to occur in the typical welding details.Welding residual stress(WRS)will cause a plastic zone at the crack tip.In this paper,an elastoplastic constitutive model based on the Chaboche kinematic hardening model was introduced,and the extended finite element method(XFEM)was used to study the influence of material elastoplasticity and crack tip plastic zone on the law of fatigue crack propagation.By judging the stress state of the residual stress field at the crack tip and selecting different crack propagation rate models to investigate the crack propagation law when plastic deformation was considered,the propagation path and propagation rate of fatigue crack of the OSBD were obtained.The results show that,whether the residual stress field is considered or not,the plastic deformation at the crack tip will not cause the obvious closure of the fatigue crack at the U-rib toe during the crack propagation process,but will significantly affect the crack propagation path.When material plasticity is considered,the propagation angle of fatigue crack at the U-rib toe basically remains unchanged along the short-axis direction of the initial crack,but is going up along the long-axis direction,and the crack tip plastic zone inhibits the propagation of the crack tip on one side.Compared with linear elastic materials,the crack propagation law considering material plasticity is more consistent with that in actual bridge engineering.In terms of the propagation rate,if the residual stress field is not considered,the fatigue crack propagation rate at U-rib toe with plasticity considered is slightly higher than that without plasticity considered,because plastic deformation will affect the amplitude of energy release rate.When considering the WRS field,the fatigue crack propagation rate at U-rib toe is increased due to the combined actions of plastic deformation and stress ratio R.

Condition Evaluation in Steel Truss Bridge with Fused Hilbert Transform,Spectral Kurtosis,and Bandpass Filter

This study is concerned with the diagnosis of discrepancies in a steel truss bridge by identifying dynamic properties from the vibration response signals of the bridges.The vibration response signals collected at bridges under three different vehicular speeds of 10 km/hr,20 km/hr,and 30 km/hr are analyzed using statistical features such as kurtosis,magnitude of peak-to-peak,root mean square,crest factor as well as impulse factor in time domain,and Stockwell transform in the time-frequency domain.The considered statistical features except for kurtosis show uncertain behavior.The Stockwell transform showed low-resolution outcomes when the presence of noise in the recorded vibration responses.The elimination of noise and extraction of meaningful dynamic properties from the vibration responses is done by applying a new method which comes from the fusion of Hilbert transform with Spectral kurtosis and bandpass filtering.The outcomes obtained from Hilbert transform processed residual signals which are further filtered using bandpass filter show more robustness and accuracy in characterizing bridge modal frequencies from the noisy vibration responses.The proposed method produces a high-resolution frequency response which can unveil the joint discrepancy in the bridge structure.

Integrity Design Strategy in Steel Structure Bridge Design

Nowadays,the scope of bridge construction projects in China is becoming wider,which promotes China's economic development to a large extent and also improves China's transportation system.Meanwhile,people also put forward new requirements for the quality of steel structure bridges.However,in actual design,due to the influence of many fectors,some problems are inevitable,which will affect the integrity of the design.Therefore,the designer needs to fully grasp the possible design problems,and then take efiective measures to improve the integrity of the design scheme,so as to ensure the quality of the steel structure bridge and improves the safety of the steel structure bridge from the fundamentals.This paper mainly focuses on steel structure bridges,analyzed the current status of steel structure bridge types and their selection,and proposes the integrity design strategy of steel structure bridges.

Comparative Study on Test Performance of Two Kinds of High Modulus Asphalt Concrete for the Steel Bridge Deck

Along with the popularization and application of the steel bridge in China,due to the high modulus of asphalt concrete with good waterproof,anti-fatigue,anti-aging and good performance,asphalt concrete with high modulus was widely used in steel bridge deck pavement,the test and comparative study of high modulus asphalt concrete were carried out based on two types of common high modulus asphalt concrete which include the casting type asphalt concrete and epoxy resin modified asphalt concrete,aims to further explore the performance features of the steel bridge deck with high modulus asphalt concrete,and provide help on the application of this asphalt concrete on the steel bridge deck.

Seismic response of the long-span steel truss arch bridge with the thrust under multidimensional excitation

Purpose–Under different ground motion excitation modes,the spatial coupling effect of seismic response for the arch bridge with thrust,seismic weak parts and the internal force components of the control section of main arch ribs are analyzed.Design/methodology/approach–Taking a 490 m deck type railway steel truss arch bridge as the background,the dynamic calculation model of the whole bridge was established by SAP2000 software.The seismic response analyses under one-,two-and three-dimension(1D,2D and 3D)uniform ground motion excitations were carried out.Findings–For the steel truss arch bridge composed of multiple arch ribs,any single direction ground motion excitation will cause large axial force in the chord of arch rib.The axial force caused by transverse and vertical ground motion excitation in the chord of arch crown area is 1.4–3.6 times of the corresponding axial force under longitudinal seismic excitation.The in-plane bending moment caused by the lower chord at the vault is 4.2–5.5 times of the corresponding bending moment under the longitudinal seismic excitation.For the bottom chord of arch rib,the arch foot is the weak part of earthquake resistance,but for the upper chord of arch rib,the arch foot,arch crown and the intersection of column and upper chord can all be the potential earthquake-resistant weak parts.The normal stress of the bottom chord of the arch rib under multidimensional excitation is mainly caused by the axial force,but the normal stress of the upper chord of the arch rib is caused by the axial force,in-plane and out of plane bending moment.Originality/value–The research provides specific suggestions for ground motion excitation mode and also provides reference information for the earthquake-resistant weak part and seismic design of long-span deck type railway steel truss arch bridges.

Analysis of Key Technologies in the Design of Small and Medium Span Basket Type Steel Box Tied Arch Bridge

In order to ensure the construction quality and safety of small and medium span basket type steel box tied arch bridge,this paper takes a practical project as an example to analyze the key technologies in its design process.It is hoped that this analysis can provide corresponding reference for the design and construction of this kind of arch bridge.

Monitoring and detection of steel bridge diseases:A review

Fatigue,corrosion,and bolt loosening are the main causes of structural performance degradation and collapse in steel bridges.Accurate monitoring of steel bridge diseases is a basic premise for ensuring high-quality operation and maintenance of steel bridges.In this regard,a summary and analysis were conducted on the classification of steel bridge diseases,monitoring and detection methods,application statuses,and major difficulties.The main causes,research status,and development trends of steel bridge diseases are discussed.The results showed that,for fatigue crack problems,fatigue crack initiation has a small scale,high difficulty in monitoring and detection,few methods,and low accuracy.As the cracks grow,the difficulty of monitoring and detection decreases,the number of methods increases,and the accuracy improves.Fatigue crack monitoring and detection are affected by the environmental and vehicular loads.Superficial corrosion features are evident in steel bridges,and corrosion identification methods and technologies are rapidly developing.Monitoring and detecting corrosion in concealed areas is difficult and requires further improvements in monitoring and detection technologies and their accuracy.Monitoring and detection methods and supporting equipment for bolt loosening in steel bridges are rapidly developing.The development of intelligent monitoring and detection technologies and supporting equipment is an important research topic that urgently needs to be addressed for the full-lifecycle operation and maintenance of steel bridges and the sustainable development of bridge engineering.Developing new intelligent sensing components based on high-performance materials and sensing element design theory to improve the monitoring and detection perception ability is an important development direction for steel bridge monitoring and detection.Research on intelligent monitoring and detection technologies,standardized indicators,and related topics based on intelligent operations and maintenance provide great support for the development of steel-bridge disease monitoring and detection.

Statistical determination of significant curved I-girder bridge seismic response parameters

Curved steel bridges are commonly used at interchanges in transportation networks and more of these structures continue to be designed and built in the United States. Though the use of these bridges continues to increase in locations that experience high seismicity, the effects of curvature and other parameters on their seismic behaviors have been neglected in current risk assessment tools. These tools can evaluate the seismic vulnerability of a transportation network using fragility curves. One critical component of fragility curve development for curved steel bridges is the completion of sensitivity analyses that help identify influential parameters related to their seismic response. In this study, an accessible inventory of existing curved steel girder bridges located primarily in the Mid-Atlantic United States （MAUS） was used to establish statistical characteristics used as inputs for a seismic sensitivity study. Critical seismic response quantities were captured using 3D nonlinear finite element models. Influential parameters from these quantities were identified using statistical tools that incorporate experimental Plackett-Burman Design （PBD）, which included Pareto optimal plots and prediction profiler techniques. The findings revealed that the potential variation in the influential parameters included number of spans, radius of curvature, maximum span length, girder spacing, and cross-frame spacing. These parameters showed varying levels of influence on the critical bridge response.

A method for examining the seismic performance of steel arch deck bridges

To examine the seismic resistance performance of a steel arch bridge during a strong earthquake,an approach is proposed in this paper to determine the ultimate strain of an arch rib using the static elasto-plastic large deformation theory.A steel fixed-end deck arch bridge with a span length of 200 m was used as an example in this study.The ultimate strain of the arch rib was calculated using the elasto-plastic finite element model.The seismic responses of the arch bridge exposed to strong earthquakes in two and three directions were also simulated.Moreover,the effect of earthquake motion in the lateral direction on the elasto-plastic earthquake response was discussed,and the seismic resistance of the structure was analyzed.The results show that steel arch bridges have preferable seismic resistance under strong earthquake conditions.While lateral earthquake motion has some influence on the damage to an arch bridge,it has little effect on the displacement,axial force,and bending moment responses of the arch rib.It is feasible to examine the seismic performance of the arch bridge by ascertaining the out-of-plane and in-plane earthquake responses of the bridge.

Stress concentration coefficients of optimized cope-hole welded detail

The fatigue performance of optimized welded detail has been investigated by fatigue experiments of three welded specimens under different loadings.In addition,local finite element models of this welded detail were established using finite element software ANSYS.The influences of different factors such as plate thickness,plate gap and initial geometric imperfections on the stress concentration coefficient(SCC) were discussed.The experimental results indicate that the fatigue life of three specimens for this welded detail is 736,000,1,044,200 and 1,920,300 times,respectively.The web thickness,the filler plate thickness and the initial geometric imperfection have relatively less effect on the SCCs of this welded detail.However,cope-hole radius is influential on the SCCs of the web and the weld.The SCC of weld is significantly affected by the weld size and plate gap,but the SCCs of other parts of the welded detail are hardly affected by the plate gap.

Design, Calculation and Model Test of Zhongshan Bridge

Zhongshan Bridge is a kind of steel arch bridge with a particular space-combined structure. The rationality of design, accuracy of theoretical calculation and reliability of transportation were studied. Its design, FEM calculation of stresses and strains, and model test were introduced in detail. The theoretical analysis and model test verified that the design was reliable and safe. The simulated stresses, rigidity and stability, which are based on the selected loading system and cross-section geometry, satisfy the related design standards. Some of the issues that need to be considered in the real bridge construction were also discussed.

Effect of rare earth content on microstructure and corrosion resistance of hot-dip Zn-5Al alloy coated steel wire for bridge cables

The effects of the content of rare earth elements on the microstructure and properties of hot-dip Zn-5 Al alloy steel wire for bridge cables were investigated.The microstructure of the hot-dip coating was analyzed using an optical microscope and a scanning electron microscope equipped with an energy-dispersive spectrometer.The bonding force between the hot-dip coating and steel wire was determined by the winding test.The corrosion resistance of the steel wire hot-dip coating was tested by the electrochemical workstation.The hot-dip Zn-5A1 alloy coating has a corrosion-resistant structure composed of a zinc-rich phase and an aluminum-rich phase.Due to the enhanced bonding force,the micro structure of the hot-dip coating of the Zn-5A1 alloy with rare earth elements is more compact and uniform than that without rare earth elements.The addition of rare earth elements improves the corrosion resistance of Zn-5A1 alloy coated steel wire.Due to the rare earth segregation,which prevents the corrosion of the grain boundary and enhances the anti-intergranular corrosion performance,steel wire exhibits the optimum corrosion resistance when the content of rare earth elements is 0.08 wt.%.