Numerical Simulation and Stress Analysis of Push-Sliding Construction of Long-Span Steel-Concrete Composite Beam Arch Bridge

To study the stress characteristics and intelligent and automated construction methods of the main bridge of a long-span steel-concrete composite beam arch bridge during push-sliding construction, this paper elaborates on the push-sliding construction scheme and key technologies, and analyzes the stress and deformation changes of the main beam, launching nose, and bearings at each construction stage using finite element software. The results show that: the application of an intelligent step-by-step push-sliding system integrating hydraulic and automated control technology for the main bridge can effectively solve the problems of efficiency and accuracy in construction; modular assembly push-sliding can adjust the stress state of the beam and avoid stress concentration caused during push-sliding; the stress changes of the main beam and launching nose during push-sliding are relatively uniform in the early stage of construction, undergo abrupt changes in the middle stage, and fluctuate more significantly, with peak values of maximum stress of 101.5MPa and 200.4MPa, respectively, which are far less than the design value of 295MPa; the deformation of the launching nose is greatly affected by the construction process, and the deformation increases sharply when approaching temporary piers L3 and L4, with a peak value of maximum vertical displacement reaching 235.2mm; temporary piers L1-L3 bear the main vertical load during the push-sliding process, and their load changes all show a trend of first increasing and then decreasing, with a maximum support reaction of 30913KN and a maximum stress of 187.2MPa, both meeting the specification requirements.