Composite Box Girder Bridges Research Articles

Shear Lag Effect and Accordion Effect on Dynamic Characteristics of Composite Box Girder Bridge with Corrugated Steel Webs

This study proposed a dynamic characteristic analytical method (ANM) of a composite box girder bridge with corrugated steel web (CBGCSW) by completely considering the impact of shear lag effect and accordion effect of corrugated steel webs. Based on energy principles and variational principles, a vibration differential equation and the natural boundary conditions of a CBGCSW were developed. The analytical calculation formula for solving the vibration differential equation was then obtained. The results calculated using the ANM agreed well with previous experimental results, which validated the correctness of ANM. To demonstrate the superiority of the ANM, the vibration frequencies of several abstract CBGCSWs with varying ratios of span–width, obtained using the elementary beam theory (EBT) and the finite element method (FEM), were compared with those obtained by ANM. The efficacy of the ANM was verified and some meaningful conclusions were drawn which are helpful to relevant engineering design, such as the observation that a higher natural vibration frequency and smaller span–width ratio significantly magnified the shear lag effect of CBGCSW. The first five-order natural vibration frequencies of the CBGCSW were significantly lower than those of the composite box girder bridge with general steel web (CBGGSW), which indicates that the impact of the accordion effect is significant.

Suggestion models of temperature differentials for the composite box girder bridge

The trend and behavior of Composite Box Girder Bridge (CBGB) are distinctly affected by the surrounding combination environment actions due to these constructions are erected in open environments. From this consideration, this research deals with the effect of the bridge’s longitudinal axis, the geometrical configuration of CBGB and the thickness of the asphalt in addition to the season parameters on the temperature differentials under the combination of the surrounding environment actions; solar radiation, atmospheric temperature, and wind speed. To achieve this aim, the full-scale experimental composite concrete slab-steel box girder segment constructed on a campus of Gaziantep University and Finite Element (FE) program (COMSOL) activated. Two temperature differential models (vertical and horizontal) introduced during the typical summer actions, which considered as the reference thermal inputs when studied all parameters. This research demonstrated that the fashion of temperature differential weather along or across the CBGB was not sensitive under all ranges of the individual parameters generally. Additionally, based on the obtained results from this research, the vertical and horizontal of temperature differential models are proposed that can aid the engineers in design practices of such constructions without restoring to experimental tests that are always costly.

Structural performance of slabs in composite box girder considering compressive membrane action

In steel-concrete composite box girders, the concrete slabs are laterally and rotationally restrained by diaphragms, surrounding slabs, and the steel box girder through shear connectors, thus developing compressive membrane action under vertical loading. However, the compressive membrane action in composite box girder bridge decks has rarely been considered, despite its significant effect on the structural performance of the slab. In this study, transverse behavior of slabs in composite box girder considering compressive membrane action was investigated and a new calculation method for assessing the load capacity of slabs with different boundary conditions was proposed. Static loading tests on six composite box girder deck slabs were first carried out. Elaborate finite element models were established and further validated by test results. Furthermore, the load capacities of the slabs were compared between the test results and several traditional theoretical predictions. It is indicated that the compressive membrane action significantly enhanced the load capacities of deck slabs. Moreover, this study reveals that ignoring the effects of rotational restraint stiffness and lateral restraint location on the compressive membrane action may lead to significant error. Based on the test results and the numerical parametric study, a new calculation method for the load capacity of laterally and rotationally restrained slabs was proposed. Comparisons with both the numerical and experimental results demonstrated that the proposed method can provide accurate and reliable predictions.

Intermediate diaphragm spacing for single-cell rectangular steel box girder bridges considering aspect-ratio

Eccentric vertical loads acting on bridge girders induce distortion of the cross-section of the steel box girder, which causes distortional warping normal stress at the flange and web of the box section in a longitudinal direction. Recent design standards specify that intermediate diaphragms, which prevent deformation of the box section, need to be installed to control these distortional warping normal stresses. In addition, the maximum ratio requirements between distortional warping normal stress and bending normal stress should not exceed 5 and 10%, respectively. However, the design standards do not provide specific formulae for use in determining the appropriate intermediate diaphragm spacing; therefore, an accurate structural analysis is required from the design stage and the iterative structural analysis time-consuming. In this study, to simplify the structural analysis steps required in the design phase, a parametric study was conducted using 3D finite element analysis (FEA) to estimate the intermediate diaphragm spacing required for composite simple span single-cell box girder bridges. In the parametric study, the box girder bridges were modeled using actual bridge data relating to the cross-sectional aspect ratio, span length, and flange thickness. The FEA results show that the coupling effects of the cross-sectional aspect ratio, the ratio of the distortional warping constant to the moment of inertia, span length, and eccentricity, have a significant effect on the diaphragm spacing and normal stress ratio. Based on these FEA results, efficient intermediate diaphragm spacing was determined in consideration of the cross-sectional aspect ratio, span length, and flange thickness.

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.

Computation of Impact Effect of Multi-span Beam Bridge under Light-Rail Vehicle

In this paper, the bending moment impact effect of a 7-span beam bridges under the single-carriage light-rail vehicle at different speeds is investigated. The 7-span composite box girder bridge is modelled using the shell element. The light-rail vehicle is modeled using the rigid beam and the spring-damper elements with 31 degrees-of-freedom. The vehicle-bridge interaction is modeled using the displacement contact method. The computed bending moment envelopes show that for the studied bridges under the concerned light-rail vehicle at the moving speeds from 80 km/h to 120 km/h, the impact effect on the positive bending moment of the first and the sixth span are the most notable: the impact factor will reach 1.742 for the first span and 1.508 for the sixth span.

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.

Dynamic and Static Load Test of PC Composite Box Girder Bridge with Corrugated Steel Web

In order to evaluate the safety of a PC composite box girder bridge with corrugated steel webs, Midas/Civil is used to analyze the bridge. Through dynamic and static load tests, the actual working state, vibration characteristics and dynamic response of the bridge under load are understood. Combined with experimental research and theoretical analysis, the comprehensive evaluation of the bearing capacity and working condition of the bridge is made, which provides reference for the design and maintenance of such bridges.

Influence of local deck vibrations on the evaluation of the maximum acceleration of a steel-concrete composite bridge for a high-speed railway

European design standards have established an upper limit on the deck acceleration of the high-speed railway bridges, however the influence of local vibrations of the deck members is rarely considered when modelling the vibrational responses of bridges. To evaluate how the inclusion of local deck vibrations might influence predictions of the maximum acceleration, detailed measurements were taken from a steel-concrete composite box-girder bridge on the Italian high-speed railway, and a numerical model of the system was developed. Deck vibrations were measured during high-speed train passages at the maximum train speed of 374 km/h, and compared against a numerical model of the vehicle-bridge system. This analysis revealed that the maximum deck acceleration is 1.3 times greater than the acceleration of the bridge girders, because of the sixth- and seventh-order resonance between the deck’s local vibration modes and the structure with a train running at high speeds over 300 km/h. Moreover, when considering local deck vibrations in the numerical model, we found that the interaction between transient local rail deformations and the vehicle travelling on the rails can increase the acceleration of the deck through resonance.

Beam-Truss Model of Steel-Concrete Composite Box-Girder Bridges II: engineering application

This paper firstly presents the field tests of a straight and a curved composite continuous box girder bridges. Elaborate FE model and beam FE model are then built on the basis of achievements of the companion paper. According to the comparison of results among elaborate FE model, beam FE model and field test, testing coefficient of mid-span deflection is 0.5∼0.8, and that of stress is 0.6~0.9 for the elaborate FE model. Also good correlation of the calculation results between elaborate FE model and beam FE model can be observed with the relative errors within the range of ±10%. This and the companion paper propose the beam-truss model of composite box-girder bridges, then accuracy and adaptability are fully verified by amounts of numerical analysis. Conclusions drawn in these papers are helpful for design analysis of steel-concrete composite box-girder bridge.

Beam-Truss Model of Steel-Concrete Composite Box-Girder Bridges I: theory and calculation

In this paper, modeling strategy for member and section level is firstly established based on shear-flexible grillage theory cellular decks. In addition, modal analysis and static analysis under the dead and live load are conducted for composite simply supported and continuous box girder bridges, the alignment of which includes straight and curve. High accuracy and good applicability of beam-truss model of composite box-girder bridge can be verified due to good correlation of numerical results between elaborate and beam FE model. The research in this paper has laid the foundation for the further application of beam-truss models in the design analysis of actual composite box-girder bridge.

Review of research on dynamic characteristics and seismic behavior of pc composite box-girder bridge with corrugated steel webs

The PC composite box-girder bridge with corrugated steel webs, as a new type of bridge structure, has obvious advantages in structure and distinct mechanics characteristic. So it has been widely applied in the engineering field. However, we have been lack of Research on the dynamic characteristics and seismic performance of the bridge. Based on a large number of documents, this paper expresses some research about the dynamic characteristics and seismic performance of the PC composite box-girder bridge with corrugated steel webs from four aspects: dynamic characteristics Analysis, dynamic characteristics test, influence factors of dynamic characteristics, and seismic performance analysis, and proposes that we should pay more attention to the theoretical analysis in the dynamic characteristics and monitoring of actual bridges to lay a solid foundation for the development of this new kind of bridge.

Experimental Study on Structural Performance of Prefabricated Composite Box Girder with Corrugated Webs and Steel Tube Slab

We present an innovative prefabricated composite box girder with corrugated webs and concrete-filled steel tube slab to prevent cracking in the web and reduce the self-weight, which is suitable for long-span structures. We carried out systematic experimental and analytical studies to investigate the structural performance, including the loading capacity and dynamic properties of a prefabricated composite box girder bridge before and after erection. Firstly, we tested a prefabricated composite girder with a single box section before erection under monotonic loading, measuring vertical deformation, flexural strain on the slabs, and shear strain on the corrugated steel webs, and evaluating the load-carrying capacity and stiffness reduction. Secondly, we conducted field live-load tests, including a calibration test and a dynamic test, on a composite bridge with twin prefabricated box girders. We hired four-axle heavy trucks for a calibration test to explore the static responses in terms of displacement, bending strain on the slabs, and shear strain on the corrugated steel webs. In the dynamic tests, we carried out a modal test using ambient vibration method and a moving load test in order to determine the dynamic behavior, which involves natural frequencies, the mode shapes, and the dynamic load factor (DLF). Based on the test results, the structural performance was evaluated by the AASHTO bridge rating process. All the findings from the load-carrying capacity test at ultimate state, calibration and dynamic load tests at service state in this study may provide a reference for the design and construction of such type of bridges.

The shear-lag effect of composite box girder bridges with corrugated steel webs and trusses

The composite box girder bridge with corrugated steel webs and trusses is a recently proposed enhanced composite box girder bridge structure. The shear-lag effect of this kind of structure is studied in detail in this research. Two 8.744 m-long test beams with and without concrete filled in the bottom steel tubes were constructed and tested. The non-uniform distribution of cross-sectional stress in the top concrete slab was captured. The filling of concrete inside the bottom steel tubes is shown not to have a great influence on the shear-lag effect. Numerical parametric studies were carried out to study the influence of various factors on the shear-lag effect of this kind of structure. The numerical results indicate that the magnitude of the shear-lag effect increases with the width-to-span ratio and the suspension ratio. Analytical equations were derived to calculate the shear-lag coefficient for composite box girders with corrugated steel webs and trusses based on the energy variational principle. The experimental and numerical validation indicates that the proposed equations can be well applied in engineering practice.

Composite box girder with corrugated steel webs and trusses – A new type of bridge structure

Composite box girders with corrugated steel webs and trusses is a new type of advanced bridge structure proposed recently. This kind of structure consists of a top concrete slab, corrugated steel webs and two bottom concrete-filled steel tubes connected by trusses. The resistance to torsion and overturning of this kind of structure is larger than that of composite bridges with a single concrete-filled steel tube. This kind of structure is able to satisfy the requirement of rapid construction, environment protection and cost effectiveness. Two composite box girder bridges with corrugated steel webs and trusses have been or are being constructed in China. This paper presents the design of these two bridges in detail, which will provide valuable engineering experience for the further promotion of this kind of new bridge structure. Experimental research has been carried out to study the flexural behavior and the flexural capacity of this kind of new bridge structure. The test results show that when the test beam is at the elastic stage, the cross-section can be viewed as a plane section if only the strains of the concrete top slab and the bottom steel tubes are considered. The test beam shows good ductility throughout the whole loading process.

Forensic Diagnosis on the Overall Collapse of a Composite Box-Girder Bridge

On 24 August 2012, a box-girder bridge collapsed under overload in China. The failed bridge served as the ramp of a city viaduct. The accident occurred when four trucks were crossing the bridge. It caused three deaths, five injuries and traffic disruption. This paper presents a forensic diagnosis of the failed bridge. Four possible causes of the structural failure are analyzed and verified through on-site graphic investigation, structural analysis and numerical simulation. Based on the accumulated information, the failure mechanism is derived and the failure process is identified. The results indicate that overall instability under the unusually heavy weight of vehicles led to rotation of the girder but did not directly cause the failure of the superstructure. A large redistribution of vertical reactions due to geometrical nonlinearity led to failure of the bent caps, which was the primary reason for the collapse of the bridge. It is suggested that lateral safety should be taken seriously for similar types of bridges and substructure strength should be adequate for future design of similar structures, especially in heavy vehicle areas.

Estimation of The Shear-Lag Effect of Composite Box Girder Bridges With Corrugated Steel Webs

Estimation of The Shear-Lag Effect of Composite Box Girder Bridges With Corrugated Steel Webs

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.

Load Distribution Factors for Composite Multicell Box Girder Bridges

Cellular steel section composite with a concrete deck is one of the most suitable superstructures in resisting torsional and warping effects induced by highway loading. This type of structure has inherently created new design problems for engineers in estimating its load distribution when subjected to moving vehicles. Indian Codes of Practice does not provide any specific guidelines for the design of straight composite concrete deck–steel multi-cell bridges. To meet the practical requirements arising during the design process, a simple design method is needed for straight composite multi-cell bridges in the form of load distribution factors for moment and shear. This work presents load distribution characteristics of straight composite multi-cell box girder bridges under IRC trains of loads.

Design of multi-span steel box girder using lion pride optimization algorithm

In this research, a newly developed nature-inspired optimization method, the Lion Pride Optimization algorithm (LPOA), is utilized for optimal design of composite steel box girder bridges. A composite box girder bridge is one of the common types of bridges used for medium spans due to their economic, aesthetic, and structural benefits. The aim of the present optimization procedure is to provide a feasible set of design variables in order to minimize the weight of the steel trapezoidal box girders. The solution space is delimited by different types of design constraints specified by the American Association of State Highway and Transportation Officials. Additionally, the optimal solution obtained by LPOA is compared to the results of other well-established meta-heuristic algorithms, namely Gray Wolf Optimization (GWO), Ant Lion Optimizer (ALO) and the results of former researches. By this comparison the capability of the LPOA in optimal design of composite steel box girder bridges is demonstrated.