Research On Key Construction Control Technology Of Wide Double-deck Steel Truss Girder Cable-Stayed Bridge

The wide double-deck steel truss cable-stayed bridge can not only hold more lanes laterally,but also have more three-dimensional traffic because of its structural characteristics.Therefore,the wide double-deck steel truss girder cable-stayed bridge can play its unique advantages in relieving the increasing traffic pressure,the future application scenario will be very extensive.As the wide double-deck steel truss girder cable-stayed bridge has distinct structural characteristics,the research on its construction control is of great significance.In this paper,based on the construction monitoring project of lianshiwan super-large bridge,the finite element model and local analysis model of the whole bridge construction process are established by using ANSYS software,and the calculated data are processed with MATLAB software,the reasonable completion state and reasonable construction state of wide double-deck steel truss cable-stayed bridge,the geometric parameter control calculation of cantilever assembly and the section matching technology are studied,the main work and results are as follows:(1)In view of the problems of the reasonable completion state and the reasonable construction state of the traditional cable-stayed bridge,such as the non-closure of the two reasonable states and the long iterative calculation time,combining the two reasonable states into one method,based on the influence matrix method and particle swarm optimization algorithm,the reasonable construction initial tension and secondary cable force are determined.The method can fully consider the internal force in the construction process,and solve the reasonable state of the finished bridge and the reasonable state of the construction in one time,particle swarm optimization algorithm can automatically optimize the cable tension without considering the differentiability of the objective function.(2)The differences and similarities of several kinds of lines(design line,finished line,manufacture line and installation line)in the design and construction of the cable-stayed bridge with wide double-layer steel truss girder are distinguished.Based on the tangent initial displacement method,the manufacturing alignment(including the longitudinal manufacturing alignment of the main truss and the transverse manufacturing alignment of the orthotropic steel deck)is calculated This paper analyzes the difference of the installation line shape between the cantilever assembly and the whole section hoisting,and calculates the installation line shape of the left and right main trusses in the cantilever assembly.(3)In view of the deformation mismatch of the deck plate of the wide double-deck steel truss cable-stayed bridge during the cantilever assembling process,the construction control of the case project is taken as the research background.A refined model of the standard beam section of the bridge is established by using ANSYS software,and the stress state of the installed beam section and the deck plate to be installed in the key working conditions during the cantilever assembly process is analyzed,the transversal deformation law of orthotropic steel deck plate of steel truss girder is obtained,and the main cause of mismatched deformation of deck plate is found.The structural optimization and technological measures are put forward,and good results have been obtained in practical engineering.