Research On Several Problems Of Jack-up Technique With The Continuous Bridge

Bridge jack-up technique as a new type of bridge reinforcement, such as replacement of important technical measures have been applied in the actual bridge project, the reform in processing because of the increase, route navigation level caused by inadequate clearance under the bridge, such as settlement of bridge and bridge bearing aging problem has incomparable advantages. Therefore, bridge jack-up technique have been paid much attention by people.In this paper, the jack-up technique application in bridge engineering system comprehensive reorganization, summarized on the basis of the key technology of a highway overpass jack-up is studied. First bridge model is established by using Midas software, according to the different conditions of box girder of jack-up beam analysis, the stress and the reaction force at the same time to check the local pressure of concrete, and the intensity of the beam is calculated, to ensure that the centre sill in the construction process of safety performance; At the same time to sync jack-up must be analyzed, in order to ensure stability performance of the centre sill in the starting process. Jack-up is also analyzed the monitoring data, it is concluded that the jack-up bridge internal force changes, the change of crack, demonstrates the importance of synchronization in the process of starting.Through the analysis of jack-up technique, draws the following conclusion:the continuous box girder in the process of jack-up must be synchronized, sync jack-up and part of the jack-up will certain effects on the beam, which affect the service life of the bridge and security; In the process of mechanical analysis, the paper analyses the method of calculating the bearing capacity of local concrete and the mechanical properties of the jack-up process centre sill do some analysis, so as to ensure the stability of the centre sill in sync jack-up process.