The Analysis Of Multi-span Prestressed Concrete Continuous Girder Bridge's Reasonable Closure Sequence

With the development of modern transportation, and the deepen understanding of engineering field to the problems such as concrete shrinkage and creep, the continuous beam closure and structure system transformation to the internal force, camber and construction deformation control,specially under the background of development and application in the expansion joints of large deformation and displacement bearing, more and more long-span prestressed concrete continuous girder bridge is widely applied in rivers,lakes and sea in our country. The long-span prestressed concrete continuous girder bridge giving full play to the continuous beam's stability under loading, high stiffness and the small vertical displacement, slightly deformation, less expansion joint, safety and satisfaction driving, the capability of overload under the live loading. But with the increase of span's length and number, on the construction of the long-span continuous girder bridge, the internal force and winding degree of structure will be changed with the extension of main beam's cantilever segment and the transformation of system, the order of system transformation has a great effect on the internal force and winding degree of structure. So how to determine the best closure proposal which can make sure the structure have good alignment and under the reasonable state, this put forward higher request to optimization research for the long-span continuous girder bridge's closure order.This paper takes Weihe eight-span continuous girder bridge as the engineering background. Studying the influence of multi-span continuous girder bridge's closure order to the structure stress and linear. Firstly combined with Ziyang-Hanjiang large bridge three-span continuous girder bridge's monitoring items, using the method for bearing simulation and temporary consolidation of continuous girder bridge to take a further analysis. Through the simulation calculation analysis and monitoring the measured data, confirm the ideal method to the bearing simulation and temporary consolidation during the bridge construction process. Second, as the all feasible scheme to Weihe large bridge, using the finite element software Midas/Civil 7.8, establish the simulation model for the bridge construction process, to many kinds of closure sequence for bridge closure researd, through to the structural deformation, internal force comparative analysis, compare the construction stability, confirm the optimal closure scheme, and ensure the beam of the bridge in case of less deflection and the force under the reasonable state to be closure successfully, which has the role of proposed to the Wei He large bridge's closure in advance, and offer reference to the same porous long-span continuous girder bridge's closure technology.