Concrete Continuous Box Girder Research Articles

Research on Monitoring Technology for Frame Piers of Continuous Box-Girder Bridges Constructed by the Cantilever Method

This paper focuses on the analysis of the stress state of a large-span frame pier-continuous box girder bridge with pier crossbeams anchored by pier crossbeams on the main pier of the Guangfo-Zhao Expressway. The bridge is constructed by the cantilever method, and a refined finite element model of the entire bridge is established using the finite element software Midas/FEA to analyze the stress state of the frame pier during the cantilever construction process. It is found that under the possible combined action of an unbalanced load during construction, the torsional resistance of the frame pier crossbeam does not meet the requirements of the design code. In order to eliminate the torsion of the frame piers, counterweights were used to monitor the frame piers during the construction of the box girders. In this paper, the theoretical calculation formula of the inclination angle of the end section of the frame pier crossbeam with the change of unbalanced bending moment, the calculation formula of the relationship between the horizontal displacement of the frame pier and the unbalanced bending moment, and the calculation formula corresponding to the relationship with the water tank counterweight are derived using the structural mechanics method. Two monitoring methods for the frame pier are proposed. In the construction monitoring of the bridge, the numerical fitting formula obtained by finite element numerical analysis calculation is compared with the calculated formula obtained by substituting the design parameters of the frame pier into the theoretical formula. The basic constants in both formulas are basically equal, verifying the correctness of the monitoring calculation formula proposed in this paper for the torsional resistance of the frame pier crossbeam. The applicability of the two monitoring methods is also compared and analyzed. This paper takes the main pier of Chaoyang overpass’s mainline bridge as the engineering background, which adopts the framework pier with a large-span prestressed concrete continuous box girder bridge. It analyzes the torsional state of the beam of the framework pier during the bridge construction process and conducts research on the construction monitoring of the framework pier crossbeam, providing valuable references for the construction monitoring of framework pier crossbeams in the construction of large-span framework pier continuous bridges in the future. The research results of this paper can provide assistance for the construction monitoring of similar projects. This paper’s innovation primarily resides in employing structural mechanics methods to compute the torsion of frame piers. On this basis, a simplified beam torsion calculation formula is proposed to strengthen its practical application in construction monitoring. The findings of this paper can help in the construction monitoring of similar projects.

Seismic Damage Analysis of Zamora Bridge in Ecuador

The Zamora Bridge, located in the Zamora-Chinchipe Province in the southeastern part of Ecuador, on the Pacific Rim seismic belt, serves as the sole river-crossing channel from the Mirador Copper Mine area to the exterior. Constructed and opened for traffic in 2013, this bridge is designed as a low-pier continuous girder bridge, featuring a three-span prestressed concrete continuous box girder for the main beam, with a span arrangement of 45.5+140+45.5 meters, and utilizes basin-type rubber bearings throughout. On May 6, 2019, and November 28, 2021, the Zamora Bridge experienced two significant seismic events. The initial seismic damage investigation revealed that the piers and foundation maintained their load-bearing capacity largely intact; the basin-type rubber bearings predominantly suffered shear failure and displacement, losing their horizontal limit capacity. Additionally, abutment blocks sheared, padstones cracked locally, and the main girder exhibited residual displacement. Following the first earthquake, repair work was undertaken based on the damage results, switching to friction pendulum seismic isolation bearings to enhance the seismic resilience of bridge. The subsequent seismic damage assessment indicated the overall stable condition of the bridge, with no observable damage, deformation, or settling to the main structure, thus maintaining basic traffic functionality. However, shear and deformation occurred to the bolts and pins fixing the direction of the friction pendulum isolation bearings, along with residual displacements after the activation of the seismic isolation function, and cracks developed in the abutment padstones and mortar layers. To delve into the performance and damage probability of vulnerable components of low-pier continuous girder bridges under various seismic intensities, numerical models of the Zamora Bridge equipped with basin rubber bearings and friction pendulum bearings were separately established using OpenSees finite element software. An analysis of the bearings' longitudinal seismic susceptibility was conducted by integrating the demand-capacity ratio and IDA method. The findings indicate that bearings, padstones, and anchor bolts are the vulnerable components necessitating reinforcement for such bridges. Compared to the basin rubber bearings, friction pendulum bearings significantly reduce the probability of bearing damage and demonstrate an excellent seismic isolation effect.

Investigation on the Through-Thickness Temperature Gradient and Thermal Stress of Concrete Box Girders

Bridges are generally affected by thermal loads which include the daily cycle, seasonal cycle and annual cycle. Thermal loads mode and thermal effects on bridges, especially for concrete girders, are quite essential but complicated. To investigate the temperature field and thermal stress in the thickness direction of a concrete box girder, the temperature field of a prestressed concrete continuous box girder bridge is monitored, and the temperature distribution in the thickness direction of the concrete box girder is analyzed. Finite element simulation, utilizing air elements specifically designed for concrete box girders, is employed to analyze the temperature field and thermal stress profiles along the thickness of the slab. The findings indicate a variation in temperature along the thickness of the concrete box girder slab. The most significant temperature differential, reaching up to 10.7 °C, is observed along the thickness of the top slab, followed by the bottom plate, with the web exhibiting relatively smaller differentials. Temperature in the full thickness range has a significant impact on the top plate, while the web plate and bottom plate are greatly influenced by temperature ranging from the outer surface to the center of the plate thickness. The temperature difference between the center of the plate thickness and the inner surface is approximately 0. The variation in temperature due to the variation in thickness direction is a temporal factor, wherein the outer layer of the roof is primarily compressed, while the inner layer is subjected to tension. The external surface of the web is mainly compressed. The stress exerted by the internal surface temperature is minimal. The internal and external surface effects of the floor are similar, and as time passes, tensile and compressive stresses appear.

Shear stress migration in a tapered girder with trapezoidal corrugated steel webs

This study conducted a comprehensive investigation into the shear stress migration of a tapered prestressed concrete (PC) continuous box girder bridge with trapezoidal corrugated steel webs (TCSWs) throughout the entire construction process, including cantilever construction, structural system transformation and external prestressing tendon tensioning. The results revealed that the basic assumptions, which state that TCSWs bear all the shear force and that only the vertical component of the external prestressing contributes to shear stress when considering its contribution, are not valid for the shear design of tapered PC girder bridges with TCSWs. The horizontal component of the external prestressing and bending moments can cause additional shear forces via the Resal effect, which results in the migration of the shear stresses between the curved bottom concrete slabs and TCSWs. This study investigated the mechanism through which the Resal effect and external prestressing influence the migration of shear stress in the entire construction process. The results revealed that within continuous girders, the Resal effect exhibits both positive and negative implications. Specifically, the negative Resal effect exerts an unfavorable influence, resulting in an increase in the shear stress experienced by the TCSWs. Moreover, this study introduced a modified shear method that that takes into account the influence of bending moments and the horizontal component of external prestressing. In contrast to basic shear methods, this approach provides notably heightened accuracy.

Rigid Spliced Box Girder Bridge under the Action of Foundation Settlement Difference Analysis of Mechanical Behavior of Splice Section

In a main line viaduct widening project, the old bridge is 35m+55m+35m three-span variable section prestressed concrete continuous box girder, which has the characteristics of large width, long span, variable section of beam body, large cantilever (4.05m), and transverse prestressed steel beams arranged on the bridge panel, etc. The old and new box girders adopt rigid joint scheme. Articles on rigid splicing box girder bridge in foundation settlement under the action of splicing mechanical properties to carry out the finite element analysis, the results show that the new bridge under the action of foundation settlement difference, longitudinal pier fulcrum position splicing under high horizontal stress, transverse middle fulcrum section splicing appeared transverse stress peak period of angular point position, may result in the crack of the concrete; There is a linear relationship between the level of additional internal force and the settlement difference of foundation, which is about 0.95MPa/mm. The calculation stress value of splicing segment can be reduced by reducing the thickness of splicing segment. In practical engineering, control and adjustment measures such as preloading of new bridge structure and selecting adjustable high support can be used to improve the force condition of splicing section[1][2].

Model Updating for a Continuous Concrete Girder Bridge Using Data from Construction Monitoring

Finite element (FE) model updating can guarantee the accuracy of the numerical analyses for civil structures. However, two deficiencies currently exist with the traditional FE model updating technique based on the measurements of modal parameters and/or the static structural responses of the built structure with respect to its reference information insufficiency and its non-unique solution generally obtained, hampering its extensive use. It becomes the goal of the whole engineering community to introduce new effective methods for the civil structural FE model update. To this end, an innovative FE model updating method using data from construction monitoring is proposed in this article. With regard to its theoretical novelty, the new method transforms the complicated multi-variable optimization mathematical problem with the traditional FE model updating technique into many simple single-variable parameter identification problems. Under the engineering background of Huangsha Harbor Bridge, a three-span concrete continuous box girder bridge constructed utilizing the symmetric cantilever casting method, the effectiveness and the efficiency of the new model updating practice were validated. It is demonstrated using quantitative data that the abundant data measured on Huangsha Harbor Bridge in construction stages can enhance the reference information for the more accurate FE model updating of the structure, and the uncertain parameters with the initial FE model of Huangsha Harbor Bridge can be progressively and easily identified for the proposed model updating method using many single-variable linear regression models, instead of one complicated multi-variable mathematical or numerical model employed by the traditional model updating approaches, which generally leads to non-unique solutions rendered by normal optimization algorithms.

Temperature-induced response reconstruction method based on DL-AR model and attention mechanism

Data loss is unavoidable for structural health monitoring (SHM) systems due to various potential factors, such as equipment aging, radio interference. Previous studies have revealed that it is more challenging to extract structural state information from incomplete data. Therefore, it is important to develop high-precision response reconstruction methods for missing data. In this study, a hybrid deep-learning and autoregressive model with attention mechanism (DL-AR-ATT) framework is proposed to accurately reconstruct structural responses considering data correlations. The proposed model consists of the deep-learning (DL) and autoregressive (AR) components, which can simultaneously model the linear and nonlinear structure of data. To adaptively weight the contribution of the two components to the final result instead of directly summing, the study introduces a custom weighting layer into DL-AR-ATT. Moreover, the attention mechanism is introduced to eliminate redundant information caused by the data from multiple sensors as input. To verify the validity and feasibility of the proposed method, long-term SHM data from a long-span steel box girder suspension bridge and a prestressed concrete continuous box girder bridge are used. The results show that the reconstruction performance of DL-AR-ATT is superior to that of the one-dimensional convolutional neural network (1D-CNN)-based and hybrid DL and AR (DL-AR) models. Finally, the weights of the modules of DL-AR and DL-AR-ATT are visualized to verify the ability of the model to capture data correlations, and to explain how the attention and custom weighting layers improve the performance of DL-AR-ATT.

Construction monitoring of a long-span prestressed concrete continuous box girder bridge with variable sections

The structural behaviors in each construction stage were monitored and analyzed against the background of a long-span prestressed concrete continuous box girder bridge with spans of 55+100+55 m. At first, the formwork erection elevation and pre-camber of the bridge in each stage, as well as stress values of key cross-sections were determined by simulating the whole construction process using the finite element software. Then, the design parameters were identified and the model was corrected by field data collection and considering various influencing factors, so as to ensure effectiveness of the model. Finally, the formwork erection elevation was adjusted according to the stress and altitude in each construction stage, followed by closure of the bridge. According to field monitoring and adjustment, the measured alignment and stress of the bridge conform to the design and the error meets the requirements of specification, indicating a favorable monitoring effect. The research can provide reference for construction of similar bridges.

Decision Analysis of a Reinforcement Scheme for In-Service Prestressed Concrete Box Girder Bridges Based on AHP and Evaluation of the Reinforcement Effect

Prestressed concrete girder bridges are widely used worldwide due to their mature construction technology, economical cost, and low maintenance. After a certain number of years of service, prestressed concrete girders inevitably suffer from deterioration of their material properties, cracking, and reduced load-carrying capacity due to the natural environment and long-term vehicle loading. When the performance of a bridge declines to the point that it cannot meet the requirements of normal use, reinforcement and maintenance are required. In this study, a 5 × 45 m prestressed concrete continuous box girder bridge that has been in service for 25 years is taken as an example, and the causes of crack development and deterioration of the technical condition of the bridge are analyzed. Based on an analysis of the causes, reinforcement schemes for overall replacement of the girder and adding bridge piers are proposed. According to a comparison of the advantages and disadvantages, a decision analysis of the reinforcement scheme is carried out via the analytic hierarchy process (AHP). The vector weights of the two schemes were found to be 0.4288 and 0.5712, respectively, indicating that adding bridge piers is more advantageous than overall replacement of the girder. Thus, a scheme of adding five piers was adopted to reinforce the bridge. A load test was then performed after the reinforcement, and both the test deflection and strain calibration coefficients were found to be less than 1, indicating that the force state of the added piers and bearings was better than the theoretical calculations. The present study shows that the reinforcement scheme of adding piers can achieve the design goal. The working status of the box girder was significantly improved, the crack development of box girder was suppressed, and the service life of the bridge was prolonged.

Numerical Analysis on Transverse Splicing Structure for the Widening of a Long Multi-Span Highway Concrete Continuous Box Girder Bridge

For the bridge widening of long multi-span highway concrete continuous box girder with a conventional splicing structure, due to the large longitudinal difference deformation by concrete shrinkage and creep between the existing and new ones, the widened structure will have an overlarge bending deformation after widening, especially an obvious transverse deformation at the end of girder, which will lead to structural damage to the newly widened structure. To effectively absorb the difference deformation mentioned above, this study proposes a novel transverse splicing structure based on the folding effect of a corrugated steel plate (CSP) (hereinafter referred to as “the CSP splicing structure”). Then, a finite element structural analysis was performed on the mechanical properties of the widened structure with the CSP splicing structure, and compared to those of a widened structure adopting the conventional concrete splicing mode, to clarify the transverse load transferring mechanism of the structure. Finally, by conducting a sensitivity analysis on CSP thickness, corrugation length, splicing stitch width, and other structural parameters, a sound parameter combination scheme was put forward. According to the research results, to ensure effective utilization of the CSP folding effect, the corrugation pattern direction of CSP should be set as horizontal, and the wave angle as the degree of 90°. In addition, it mitigated the transverse tensile stress to effectively avoid concrete cracking feasibility on the top flange of the box girder at the end of the girder. This study offers a feasible way of avoiding the structural damage produced by an excess transverse deformation at the end of the girder after bridge widening of a long multi-span concrete continuous box girder.

Safety Monitoring of Bearing Replacement for a Concrete High-Speed Railway Bridge Based on Acoustic Emission

As an important part of a bridge, bearings easily suffer damage when exposed to various loading and environmental changes during their lifetime. Bearing replacement should be performed in a timely manner if damage occurs to high-speed railway (HSR) bridges. The unique structural form and strict operation requirements mean that bearing replacements of HSR bridges are much more difficult than those of highway bridges. However, compared with bearing replacements of highway bridges, far fewer scientific and engineering studies have been conducted to guide the bearing replacement of HSR bridges. In this paper, based on a three-span continuous concrete box girder HSR bridge, an innovative bearing replacement method using reverse disassembly and assembly techniques is proposed and was implemented at a location under operating HSRs. In addition, safety monitoring measures were undertaken to guarantee the safety of the bridge during bearing replacement. In contrast to the usual monitoring practice focusing on the displacement and the external strain of the structure, this monitoring work adopted the acoustic emission (AE) detection technique to explore the internal structural damage formed in the process of construction. The results suggest that the proposed bearing replacement method, which requires the girder to be jacked up by no more than 9 mm, is a promising practice for this complicated construction, and the start time and evolution of damage in the concrete of a bridge during construction can be captured accurately by AE detection with a parameter-based analysis method. All practices presented in this case study can guide future bearing replacements in similar projects.

Slip analysis of prestressed steel-concrete continuous composite beam

To analyze the horizontal shear resistance participation degree of the shear studs on the web and diaphragm flange in the negative moment area of the steel–concrete continuous composite box girder, the steel–concrete composite girder specimen was designed and manufactured based on the existing codes. The shear deformation of the two parts of the studs in the composite box girder is studied by the finite element parameter analysis of the nonlinear shear deformation of the studs and the stress analysis of the diaphragm. The results show that web flange studs provide the horizontal shear capacity of the steel–concrete composite box girder. The installation of baffle flange studs cannot improve the shear connection degree of composite beams. Removal of the flange stud from the diaphragm can relieve the force on the diaphragm and provide a theoretical basis for reducing the stiffeners of the diaphragm.

Research of construction monitoring technology of large-span variable cross-section prestressed concrete continuous box-girder bridge

With the advancing development of structural performance and construction techniques, continuous concrete box girder bridges have been widely used due to their advantages including their broad applications, good appearance, and reliable structural safety. However, as the bridge span and its construction demands are increasing, the bridge construction process tends to be more complex. Especially, the construction methods and bridge installation sequences of cantilever bridges not only exert structural internal force on the bridge construction process but also affect the internal force and line shape of the bridge structure of finally constructed bridges. Hence, it is essential to realize bridge construction control. Only in the presence of the excellent construction control performance, can the structural safety in the bridge construction process can be ensured while meeting the designed requirements of bridge line shapes and internal forces of constructed bridges. In this research, by taking the Weihe grand bridge located at Shandong Province, China as construction background, the specific targets and methods of bridge construction control were introduced for the reference of bridge construction and research.

FORENSIC ANALYSIS OF THE WUXI 312 VIADUCT OVERTURNING COLLAPSE

On October 10, 2019, a three-span concrete continuous box girder on National Highway 312 in Xishan District, Wuxi City, overturned under the action of two vehicles. Investigated the accident site first, then established a geometrically nonlinear finite element model based on wreckage photos and construction drawings, and studied the overturning mechanism. An overload determination method based on the strength and overturning stability effects is proposed. The results include: the overturning test results based on the standard lane load demonstrate that the bridge does not meet the overturning test requirements specified in the Specification for Design of Highway Reinforced Concrete and Prestressed Concrete Bridge and Culvert (2018 edition); the superstructure under the action of the overloaded vehicle first rotated, then slid, and finally exhibited a combination of substantial rotation and sliding overturning mode; the superstructure has a certain safety margin between bearing separation and overturning; the calculation based on the strength and overturning stability effect proves that the overturning effect generated by the overloaded vehicle is greater than the overturning capacity of the structure, indicating that the overturning is mainly attributed to the overload. However, the structural bending capacity turns out to be sufficient through further calculation, indicating that the overturning damage occurred earlier than the occurrence of strength damage, and that the overturning resistance and bending resistance do not match.

Internal Forces Analysis of Prestressed Concrete Box Girder Bridge by Using Structural Stressing State Theory.

This paper analyzes the working behavior characteristics of a prestressed concrete transverse large cantilever continuous (PCTLCC) box girder bridge model based on structural stressing state theory and the numerical shape function (NSF) method. At first, the normalized generalized strain energy density (GSED) is established to model the stressing state of the bridge model. Subsequently, the Mann Kendall (M–K) criterion is applied to detect three characteristic loads, respectively, elastic–plastic branch load P (200 kN), failure load Q (300 kN), and progressive failure load H (340 kN), and the failure load Q is found to be the starting load of the damage process of the bridge model, rather than the ultimate load where the structure has been destroyed. Finally, the NSF method is adopted to interpolate the test data, and a detailed analysis for the variation characteristics of the working behavior of the bridge model under loads is performed based on the interpolation results. The characteristic load detection method and experimental data extension method for PCTLCC box girder bridge established in this study can provide valuable references for the design and analysis of such bridges.

Temperature Effect on Main Girder of Strengthened Dongming Huanghe River Highway Bridge in Service

The main girder of Dongming Huanghe River Highway Bridge was the first prestressed concrete (PC) continuous box girder bridge strengthened by a cable-stayed system in China. In order to study the temperature effect of the main girder structure of Dongming Huanghe River Highway Bridge after reinforcement, based on the measured data of middle span deflection, key section strain and typical crack width, the curve equations of strain and temperature of main girder were obtained by the regression analysis method. The results show that the annual strain value of main girder changed with the acquisition time in a sinusoidal function, and was linearly related to the temperature. The variation of mid-span deflection decreased gradually from side span to middle span, and varied dynamically with temperature in the whole girder, which also has obvious correlation with temperature. The crack width fluctuated up and down in a certain numerical range, which belonged to respiratory cracks and had equally correlation with temperature.

Risk-Based Multiobjective Optimal Seismic Design for RC Piers Using the Response Surface Method and NSGA-II

In this paper, a risk-based multiobjective optimal seismic design method for reinforced concrete (RC) piers is proposed. This method is used to determine the size and reinforcement ratios of piers to minimize the seismic risk of bridge systems and the construction cost of piers. The Pacific Earthquake Engineering Research- (PEER-) based probabilistic seismic risk assessment approach and the response surface method (RSM) are adopted to develop the seismic risk response surface model, which represents the relationship between the design parameters of piers and the seismic risk of bridge systems. The Pareto optimal solutions of piers are determined by applying an improved version of the nondominated sorting genetic algorithm (NSGA-II). As a case study, the proposed optimal seismic design method is applied to a continuous concrete box girder bridge. The optimal design schemes of piers according to two strategies are determined from the Pareto optimal solutions. The results show that the seismic risk response surface model can be used to accurately describe the relationship between the design parameters of piers and the seismic risk of bridge systems. The case study demonstrates the effectiveness of the proposed optimal seismic design method. The analysis of the Pareto optimal solutions allows designers to more rationally conduct the seismic design of piers.

Static behavior of a steel-ultra high performance concrete continuous composite box girder

To improve the crack-resisting behavior of normal-strength concrete (NC) bridge deck and to reduce the deadweight of conventional steel-concrete composite girders, a new steel-ultrahigh performance concrete (UHPC) continuous composite box girder was proposed. Aiming to reveal the static behavior of the proposed structure, including the load-deflection response, the strain distribution, the crack development, the moment redistribution and the failure mode, a comparative experimental study was conducted on two types of the composite girder, namely a steel-UHPC continuous composite girder (SUCG) and a prestressed steel-concrete continuous composite girder (SCCG). The test results indicated that the ultimate loading capacity of the SUCG was 20.4% higher than that of SCCG; the nominal cracking strength of the SUCG was 22.9 MPa, and its corresponding cracking moment was 2.1 times higher than the conventional one; the crack development mode of UHPC slab were significantly different from the SCCG, the cracks appeared in UHPC slab dominated by microcracks with smaller length were numerous and intensive. It is also shown that the SUCG has smaller degree of moment redistribution. Thus, the current study verified the SUCG could be one of effective solutions for long-span continuous composite girder bridges.

Static Strength of Friction-Type High-Strength Bolted T-Stub Connections under Shear and Compression

The friction-type high-strength bolted (FHSB) T-stub connection has been widely used in steel structures, due to their good fatigue resistance and ease of installation. While the current studies on FHSB T-stub connections mainly focus on the structural behaviors under both shear and tensile force, no research has been reported on the mechanical responses of the connections under the combined effects of shear and compression. To make up for this gap, this paper presents a novel FHSB T-stub connection, which is simple in structure, definite in load condition, and easy to construct. Static load tests were carried out on 21 specimens under different shear–compression ratios, and the finite-element (FE) models were created for each specimen. The failure modes, initial friction loads and ultimate strengths of the specimens were compared in details. Then, 144 FE models were adopted to analyze the effects of the friction coefficient, shear–compression ratio, bolt diameter and clamping force on the initial friction load and ultimate strength. The results showed that the FHSB T-stub connection under shear and compression mainly suffers from bolt shearing failure. The load–displacement curve generally covers the elastic, yield, hardening and failure stage. If the shear–compression ratio is small and the friction coefficient is large, its curve only contains the elastic and failure stage. The friction coefficient and shear–compression ratio have great impacts on the initial friction load and ultimate strength. For every 1 mm increase in bolt diameter, the initial friction load increased by about 10%, while the ultimate strength increased by about 8.5%. For each 10% increase/decrease of the design clamping force, the initial friction load decreases/increases by 7.8%, while the ultimate load remains basically the same. The proposed formula of shear capacity and self-lock angles of FHSB T-stub connection can be applied to the design of CSS-enhanced prestressed concrete continuous box girder bridges (PSC-CBGBs) and diagonal bracing.

Tensioning-Phase Box Girder Deformation Prediction Model Based on Ant Colony Algorithm and Residual Correction

The girder of prestressed concrete continuous box girder bridge strengthened by a stay cable system has a very complex deformation mechanism, and it is difficult to establish accurate numerical model for prediction. For these problems, a prediction method based on the combination of ant colony algorithm and residual combination correction model is proposed. In this method, the measuring points are considered as the cities in TSP ant colony algorithm, the information function model and heuristic function model are constructed, the pheromone update mechanism and ant search mechanism are established, and the deformation prediction of the main girder based on ant colony algorithm prediction model is achieved. On this basis, in order to fit the random change process of main girder deflection better, the periodic function generated by harmonic transform and sine function are introduced to modify the predicted results, which makes up for the low precision defect of single model. The results show that compared with finite element method, unequal interval gray model (1,1) (UIGM (1,1)), one-time residual correction UIGM (1,1), Markov chain residual correction UIGM (1,1), and ant colony algorithm model, this model can reflect the space-time effect and casual fluctuation feature of the development of girder deformation better and also has higher prediction accuracy and efficiency. The mean relative error of the predictive value is 3.39%, the posterior error ratio is 0.060, and the accuracy level reaches level 1. This model provides a new way for the girder deformation prediction of bridge strengthened by the stay cable system.