Research On Construction Control And Wind-induced Stability Of Long-span Asymmetric Continuous Rigid Frame Bridge In High-speed Railway

Abstract:Prestressed concrete continuous rigid frame bridge holds a dominant position in long-span bridges of high-speed railway for its advantages of reasonable force, simple construction and long-span capacity.The bridge construction control is indispensable in order to guarantee the quality and security of bridge construction,and meet the design requirements of girder geometry and internal force in the finished dead state.Based on practical project of the main bridge of Beijiang Bridge,some research was made as follows:First of all,the development process of prestressed concrete rigid frame bridge and bridge construction control at home and abroad is introduced,and the importance of bridge construction control is elaborated.A suitable construction control method is given for the bridge with the related theory of construction control. The process of construction is analyzed by establishing calculating model with Midas/Civil,so that the deformation and stress of every construction phase are provided to direct the construction;Secondly,in the process of construction on prestressed concrete rigid frame bridge,the structure is affected by different errors which lead to difference between the actual values and theoretical calculating values in the deformation and internal force.Therefore,the control of linearization and stress is explored.Next,the application of least square method and Kalman filtering method is particularly presented,which is for the error adjustment;the control achieves good results through the combination of the two methods:compared with theoretical calculating values,elevation error of bridge deck is negative13mm to positive15mm after completed and stress error is about0.5MPa.In addition,the reasonable calculation method of jacking force for mid-span closure and the template method of relative coordinates are put forward;Finally,by comparing the methods of calculating wind load in different codes, the reasonable one is put forward for wind-resistant analysis.At the same time, the stress caused by typhoon which happened in the construction is analyzed and the stability is also analyzed in the largest cantilever stage with different wind load arrangements.