Study On Linear Control Of Mobile Construction Of Large Span Continuous Box Girder Bridge

In the large span prestressed concrete girder bridge,prestressed concrete continuous girder bridge has the advantages that its span is large,maintenance is convenient,the expansion joint is little,the structure is good,the operation is comfortable,the additional internal force of the continuous girder bridge is reduced.The construction technology of mobile because of its own advantages,more and more used in bridge construction.Moveable formwork construction process of the bridge linear control there are many factors,different influence factors on the structure of the linear effect is not the same,the bridge structure of the geometric deformation is dominated by setting pre arch degree of control,mobile form construction method of pre camber setting general based on the actual project did not an accurate calculation method.Study on the key technical problems of construction of large span continuous beam construction method based on.Formwork construction linear control factors are the load,which concrete density,elastic modulus,shift time mode and structural deformation etc.factors for the main effect of linear change of factors.Analysis main influence factors and in view of the factors to be controlled,to the actual linear control of the bridge meet the design requirementsCombined with mechanics and bridges the theory derivation formwork construction of continuous beam deformation calculation formula.The mathematical model is used to simulate the whole process of the construction,formwork in construction in the process of moving the structure of vertical deformation values are calculated,and the load effect of the finite element analysis.The results show that: the cross pouring completed,tension reinforcement pull at the end of the deformation value,subsequent cross for pouring concrete gravity effects that have been pouring across the deformation value changes due to,span more far,effect is small,the whole bridge pouring Zhang tension,bridge eventually deformation need second phase load pavement and considering the influence of temperature stress.Different from other methods,the actual deformation of bridge formwork construction is the result of superposition of bridge structure deformation and deformation results of the mould frame girder,deformation by preloading test,thecoupling effect between the whole construction process of bridge body and frame can not be ignored,the cast-in-situ frame cross deformation die equivalent node force is exerted on the main girder has been pouring across the cantilever,the node stress analysis in the effect of deformation has been poured across the bridge,and the final deformation value and,the comparison results show that: the field data closer to the frame and the main beam considering the interaction between the design of elevation for more,that in the actual construction process,mold the deformation of the pre camber effect can not be ignored,for similar engineering accumulation materials and provide guidance.