Research On Construction Control And Key Technology Of Curved Groove Girder Bridge

In recent years,with the rapid development of China's transportation industry,urban rail transit has proposed a higher development concept.The curved beam with beautiful lines and the U-Shaped beam with the advantages of energy saving and noise reduction have been promoted and widely used.With the increase of railway routes,the rotating construction method has become the main construction method across existing railway routes.In order to ensure the safety and stability of new bridges and the safe operation of existing railways under the bridge,construction monitoring is particularly important.At present,there are many studies on the construction monitoring of box girder swivel in China,but there are few studies on the monitoring of the curved U-Shaped beam construction.In this paper,the Wuhan curved U-Shaped beam rigid frame bridge is taken as the engineering background,and the key problems in the construction monitoring of the curved U-Shaped beam are studied.The main contents are as follows:(1)According to the development status of U-Shaped beams at home and abroad and the development status of swivel construction,the research objectives and significance of this paper are put forward.The mechanical characteristics of curved girder bridges and U-Shaped girder bridges and the construction technology of swivel bridges are briefly introduced.(2)Explain the analysis method of curved U-Shaped beam,and establish single beam model,beam grid model and solid model according to the analysis method.By comparing with the measured values,it is determined that the beam grid method is the optimal modeling method for the monitoring of curved U-Shaped beam construction;(3)Use Midas/Civil finite element software,establish the beam grid model of curved U-Shaped beam,calculate the deformation and stress of control section,compare and analyze the linear,stress and measured values of each construction stage to ensure the safety of the whole construction process.The linear shape and stress state of the bridge meet the design requirements;the unbalanced weighing test and the counterweight of the rotating structure ensure the safe and smooth completion of the swivel structure of the upper structure(4)Applying Midas/FEA finite element software to establish the T-shaped structure of the curved U-Shaped beam.By changing the eccentricity of the bearing,the influence of the eccentricity of the bearing on the internal force and stability of the beam is studied,and the eccentricity of the bearing is increased.The unbalanced moment,beam stress and beam end deflection of the structure are effectively improved,which greatly increases the stability of the T-structure of the swivel.(5)The local finite element model of the 0-block of the curved U-Shaped beam is established,and the stress distribution under the maximum cantilever state is analyzed.It iscalculated that the block No.0 is in a safe stress state,and the position where the maximum tensile stress appears is indicated.This paper provides a certain reference for the design and construction of the block No.0 of the curved beam type.