Concrete Composite Box-girder Bridge Research Articles

Seismic Vulnerability Analysis of Long-Span Prestressed Concrete Composite Box Girder Bridge with Corrugated Steel Webs under Construction

In order to address the difficulty in determining the seismic damage probability of continuous girder bridges under construction, the seismic vulnerability analysis method of the construction state is proposed in this study. Firstly, taking a long-span prestressed concrete composite box girder bridge with corrugated steel webs (OSW) as an example, the finite element models (FEMs) of dynamic calculation in different phases of cantilever construction are simulated by OpenSEES. Secondly, by selecting reasonable seismic waves and seismic intensity measures, the non-linear time-history analysis is carried out, followed by the demand parameters and damage indexes suitable for the construction state proposed. Finally, the probabilistic seismic demand model (PSDA) of the continuous box girder bridge during the construction stage is constructed by using the “cloud method”, and the seismic vulnerability curves of the piers and temporary bearings are established to evaluate the seismic performance during the construction stage. The results indicate that the damage probability of piers and temporary bearings increases with the progress of construction. The initial formation of the cantilever structure and the sudden change in the size of the construction segmental girder correspond to a high probability of damage, and seismic protection measures should be strengthened during this construction state. Moreover, significantly higher damage probability of the components under construction compared to the completed bridge after it is built.

Dynamic Analysis of a Steel–Concrete Composite Box-Girder Bridge–Train Coupling System Considering Slip, Shear-Lag and Time-Dependent Effects

A dynamic computational program considering slip, shear-lag and time-dependent effects of composite box-girder bridge–train coupling system is firstly proposed based on the authors’ previous studies. In the program, the long-term vertical displacement of a composite bridge is firstly calculated. The calculated vertical displacement is then superimposed on the existing uneven track as the new excitation of the composite box-girder bridge–train coupling system to obtain the dynamic responses of the bridge–train coupling system. A 3 × 40 m simply supported steel–concrete composite box-girder bridge is selected to investigate the influence of its time-dependent behavior on its dynamic responses. The results showed that the time-dependent effect will amplify the dynamic characteristics of the composite box-girder bridge and the high-speed train. The maximum vertical displacement and acceleration of the composite bridge increase by 8.82% and 13.64%, and the maximum vertical acceleration of the train body increases by 144.78%. Additionally, the slip and shear-lag effects have an impact on the dynamic responses of the composite box-girder bridge–train coupling system at different operation times. The dynamic responses of the coupling system strengthen with the decrease in shear connection stiffness. The dynamic responses of the system may be underestimated when the shear-lag effect is not neglected. Therefore, these conclusions should be given sufficient attention in the design, construction and operation of high-speed railway composite bridges.

Mechanical Performance Analysis of Prestressed Concrete Composite Box Girder Bridge with Corrugated Steel Webs under RW Cantilever Construction

As a new type of steel-concrete composite bridge, PC composite box Girder Bridge with corrugated steel webs has been rapidly developed in China in recent years. With the deepening of research, a new type of construction technology - RW cantilever construction began to be applied to the construction of such bridges. This paper first introduces the general steps of RW cantilever construction and the advantages compared with traditional cantilever construction. Then, take a continuous rigid frame bridge with corrugated steel webs under RW cantilever construction as an example, and build its finite element model. The crack resistance and compressive stress of the concrete and the shear stress of the corrugated steel web were checked to meet the requirements of the specification, and the feasibility of the construction method was verified.

Analysis of Shear Connector of Steel–Concrete Composite Box-Girder Bridge Considering Interfacial Bonding and Friction

Steel–concrete composite bridges consist of steel and concrete parts which are connected by shear connector such as the widely-used headed stud. Through the chemistry bonding, interface friction and mechanical action the two different materials parts are combined as a composite structure system. Because of the structural mechanism, longitudinal and lateral relative slip and normal separation between the concrete deck and steel girder flange will inevitably exist during the loading process. Further, the complex interface mechanical behavior causes difficulties with nonlinear numerical analysis. Multiple broken lines mode cohesive zone model considering bonding and friction is used in this paper to describe the tangent slip and normal crack of the interface. A zero thickness cohesive element was implemented via the user-defined element subroutine UEL in ABAQUS. Using this method, numerical simulation analysis of a two span composite continuous box-girder was carried out. Results showed load–displacement curves of the structure, relative displacement between the steel girder and the concrete slab interface, interface stress distribution, and internal force of shear studs. Discontinuous deformation numerical simulation has been realized, and effectiveness of the proposed method and accuracy of the program were verified. Although shear stress was assumed to be transmitted by shear connector in the design stage, interface bonding and friction resistance can affect the force state of the shear connector. Results of this study can be used for detailed analysis and evaluation of the composite box-girder bridge without the need to rely on the constitutive laws of shear connectors obtained from push-out tests.

Effect of intermediate diaphragms on the load – carrying capacity of steel – concrete composite box girder bridges

Intermediate diaphragms are used in box girders not only to prevent premature distortion under eccentric loading conditions but also to improve the distribution of live loads. This paper reports an investigation into the effect of intermediate diaphragms on the load - carrying capacity of a Steel – Concrete Composite Box (SCCB) girder bridge with open steel box section. In the current study, a three - dimensional finite element (FE) model of the SCCB girder is developed and analyzed using ABAQUS software. The nonlinear inelastic analysis is invoked in order to accurately capture the actual behavior of the girder. The numerical model is verified with experimental results to ensure the accuracy of the FE modeling method. A parametric analysis is implemented to study the effect of intermediate diaphragms on the load – carrying capacity of an SCCB girder with a 30–60m span length. Based on parametric studies, the number of intermediate diaphragms (N) is recommended for practical design of the girder, which satisfies the requirement stated in the provisions of the AASHTO LRFD standard.

Application of ZLD Automaticly Continuous Launching System in the Construction of Prestressed Concrete Composite Box-girder Bridge with Corrugated Steel Webs

The incremental launching construction method firstly is applied to the prestressed concrete composite girder bridge with corrugated steel webs and the bridge belongs to Zhengzhou Longhai Road Fast Track Project at Chang-zhuang reservoir in domestic. Under this background, ZLD automaticly continuous launching system is applied to the prestressed concrete composite girder bridge with corrugated steel webs and the construction scheme design, related construction technology and key points is introduced. Engineering practice shows that the advantage is synchronous control, automation, flexible construction, the force of incremental launching can be adjusted according to level of reaction force and deformation at the pier top. The construction efficiency, safety and reliability is improved for launching engineering, and it has a wide application prospect.

Mechanical Analysis of the Superstructure of Prestressed Concrete Composite Box-Girder Bridge with Corrugated Steel Webs

The superstructure of H-bridge is prestressed concrete composite box-girder with corrugated steel webs with a main span of 90m, and the span arrangement is 52m+90m+52m. In this paper, the finite element method is used to model H-bridges superstructure and do analysis of construction stage and completed bridge stage, and the analysis is checked with the current corresponding regulatory of bridge design and construction. Checking results show that under the existing highway-level loads, the main beams carrying capacity, stress, crack resistance, deformation and corrugated steel webs shear strength and shear stability meet the regulatory requirements. The checking process also reflects the mechanical properties of corrugated steel web.

Numerical Analysis on the Dynamic Characteristics of South-to-North Water Division Bridge during the Cantilever Construction Stage

The South-to-North Water Division Bridge is a prestressed concrete composite box-girder bridge with corrugated steel webs constructed by cast-in-place cantilever method. Its modal shape and modal frequency were calculated during each cantilever construction stage. And the formula about the relation between length of cantilever and natural frequency was derived.

Finite Element Analysis Simulation of the South-to-North Water Diversion Bridge during Cantilever Construction

Use the Finite Element Analysis software to numerically simulate the South-to-North Water Diversion Bridge, a prestressed concrete composite box-girder bridge with corrugated steel webs, during the process of cantilever construction. Then research the force condition of the main girder structure during the construction processes. Results indicated that, during each construction process, the bending moment was reasonable, and all sections of the main girder structure were under pressure. The maximum normal stress always appeared around those cross-sections over the main piers, and during the mid-span closure process, the maximum stress appeared around the mid-span segment’s bottom flange.

Analysis of the Closure Method of Cantilever Construction PC Box-Girder Bridge with Corrugated Steel Webs under Asymmetric Constraint

The 4th Nanjing Yangtze River Bridge North Terminal Chuhe Bridge is a prestressed concrete composite box-girder bridge with corrugated steel webs constructed by cast-in-place cantilever method. In order to shorten the construction period, it takes the closure scheme which is under asymmetric constraint. In this paper the force and stress in each important construction stage under different closure schemes were analyzed. The results showed that the procedure of the closure method under asymmetric constraint is feasible.

Analysis of the Superstructure of South-to-North Water Diversion Bridge

Based on the South-to-North Water Diversion Bridge (70m+120m+70m prestressed concrete composite box-girder bridge with corrugated steel webs), structural static analysis of the bridge’s superstructure was taken out by finite element method, which were checked with the existing regulatory requirements. The result indicates that the carrying capacity in the ultimate limit state meet the requirement of the standard, the vertical shear stress of corrugated steel web satisfies the standard limit and the thickness of corrugated steel web satisfies the request, but the safety factor is not high.

Bracing for composite box girder bridges

For steel–concrete composite box girder bridges, the steelwork is generally erected first and then the concrete deck cast. During construction the girder may be subjected to a variety of construction loads. If the girder is a flexible open section, and lacks distortional or torsional stiffness, the cross section will deform or twist excessively; such difficulties with box girder construction have been reported. Bracing systems should be installed to increase the torsional and distortional stiffness of the open section during construction. A finite strip analysis of the influence of bracing systems on open section box girders is presented and compared with test results obtained using a one-quarter scale model. With the analysis, the influence of ties, distortional bracing, torsion boxes, and top chord bracing on the behaviour of torsionally open box girders is examined. Simplified design methods are also presented whereby the bracing forces and the stresses arising from the distortion of the section can be computed. Key words: bridges (box girder), bridges (steel), box beams, torsional distortion, bending distortion, bracing, construction safety.

Live load field test on the Muskwa River Bridge

The performance of a steel–concrete composite box-girder bridge is examined through a series of live load field measurements. This paper describes the measurement program and the results obtained, as well as comparisons wherever possible between the observed values and those obtained from beam theory calculations and bridge code equations. It was found that the measured strains were generally much lower than the design values and that for bridges with asymmetrical cross sections, a beam theory calculation using bridge code live load distribution formulas can lead to nonconservative results.