Structural Analysis And Construction Monitoring Research Of Long-span Curved Continuous Girder Bridge

In the past dozens of years,with the continuous development of the economy and the continuous progress of the transportation industry,more and more bridges have been used in roads and railways.Because of the beautiful appearance of the curved continuous beam bridge,it can better adapt to various the advantages of such terrain conditions,fewer bridge expansion joints,and good earthquake resistance have been widely promoted in the transportation field.However,during the completion of the curved continuous beam bridge,there are many external factors affecting the internal force and linearity.Therefore,it is necessary to analyze the impact of the construction and the structure of the bridge itself to ensure that the final construction can meet the linear and stress design requirements.The safety of the final construction.Based on the Pingyi Interchange G ramp of Xintai Expressway,combined with the actual project,it is arranged in a span of 36+60+36m.The curved bridge is simulated by Midas/Civil and the construction is guided according to the results of the finite element simulation.The influence of the changes of various material parameters on the stress and deformation of the curved girder bridge is studied,and the influence of geometric or material parameters on the full bridge is analyzed in combination with the force characteristics.Compare and analyze the influence of the radius of curvature on the bridge,analyze the completed and uncompleted(maximum cantilever state)of curved continuous beam bridges with different curvature radii,mainly focusing on the different curvatures of the vertical displacement,horizontal displacement,torsion angle and internal force.The changes under the radius are analyzed.The main monitoring section is obtained through calculation,and the expected value is achieved through the control and analysis of the main monitoring section of the curved bridge.The main contents are as follows:(1)Perform finite element simulation on the Pingyi Interchange G ramp of Xintai Expressway,and analyze the deformation and internal force changes of the bridge in combination with different construction conditions.Through analysis,the most unfavorable cross-section of curve bridge deformation and stress is obtained.The 0block on the top of the pier,the cantilever end of the largest cantilever state,1/2 of the side span,and the mid-span cross section of the completed bridge are selected as the main monitoring and control sections.(2)Through the finite element software Midas/Civil,the sensitivity analysis of the Pingyi Interchange G ramp is carried out,and the concrete bulk density,concrete elastic modulus,prestress error and concrete time are mainly selected for parameter analysis.The analysis shows that the biggest influencing parameter of the curve bridge is the tension control stress.Whether it is internal force or deformation,the tension stress has the greatest impact on the curve bridge.Sensitivity analysis is used to find out the stress point where parameter changes have the greatest impact on construction,so as to strengthen the monitoring of this point and ensure construction safety.(3)Establish curved bridge models with different curvature radii according to the actual engineering background,study the beam deformation and structural stress characteristics of curved beam bridges in different construction stages,and compare the completed and uncompleted curved continuous beam bridges with different curvature radii(Maximum cantilever state)The analysis mainly focuses on the changes of vertical displacement,horizontal displacement,torsion angle and internal force under different radii of curvature.The study shows that the change in the radius of curvature has the least effect on deformation in various states.Vertical displacement: The most influential is the horizontal displacement of the maximum cantilever state,with an increase of164%,which is a linear change that needs to be monitored in monitoring.(4)According to modern monitoring theory,combined with monitoring examples,through Midas/Civil for theoretical modeling and analysis,the main section of the curved continuous beam bridge with a curvature radius of 250 m on the Pingyi Interchange G-Ramp(36m+60m+36m)Linearity and stress monitoring,monitoring results meet the design of the bridge state,and provide reference for subsequent similar projects.