Analysis On Construction Control And Mechanical Properties Research Of Prestressed Concrete Continous Beam Bridge

In the actual construction process,the internal force and displacement of the cantilever system of prestressed concrete continuous beam bridge are constantly changing.In order to ensure that the finished state of the continuous beam bridge is consistent with the design,the alignment and internal force meet the design requirements,and the structure has enough safety and stability in the construction process,the construction monitoring of the bridge is indispensable.Based on the engineering background of Sanyuan Road Pi River Main Canal Bridge,the finite element model of the whole bridge was established with MIDAS civil 2019.On this basis,the construction monitoring and mechanical properties of the bridge are studied.The main contents of this paper are as follows:(1)The finite element model of the bridge was established and the whole construction process was simulated.The stress and deformation of the key control section of the bridge were obtained,which provides a theoretical basis for the measured results of the subsequent construction process.Combined with the stress characteristics of the bridge,the construction monitoring was compiled,and the parameters were modified in real time according to the actual construction situation,so as to control the alignment and stress of key sections and ensure the reasonable alignment of the bridge.(2)In view of the influence of actual construction technology,temporary construction load,concrete shrinkage and creep,foundation settlement and measurement error,the actual values of the structure are different from the theoretical values.Therefore,it is necessary to carry out targeted research on some problems that may appear in the process of construction monitoring,which mainly includes the checking calculation of the cradle structure,the influence of the system transformation scheme on the internal force of the structure,the influence of the foundation settlement on the linearity and stress of the main beam,the sensitivity analysis of relevant parameters and the application of grey system theory in the linear control.(3)This paper summarizes the research status of single column pier bridge instability,explores the reasons for the lateral instability of the bridge,carries out the overturning resistance calculation of the bridge,and studies the overturning resistance performance of the bridge under different working conditions and bearing spacing.The results show that the most unfavorable condition in the calculation of overturning resistance stability of straight-line single column pier beam bridge is two lane eccentric load,and the stability of single column pier beam bridge can be greatly improved by appropriately increasing the support spacing within a certain range.(4)The calculation results of dynamic characteristics show that the vertical vibration of the main girder is the main vibration form of the bridge.The transverse and longitudinal seismic responses of the bridge are analyzed by response spectrum and time history analysis methods respectively.The results show that the torque at the bottom of pier is mainly affected by the longitudinal earthquake,and the asymmetry of bridge side span will have a negative impact on the overall stability of the bridge.The construction control and mechanical analysis of long-span prestressed concrete continuous girder bridge can effectively guide the construction of Sanyuan Road Pi River Main Canal Bridge and ensure the quality and safety of the bridge construction.