Analysis of Construction Control of Arch-shaped Pylon Alignment of High-speed Railway Arch-shaped Pylon Cable-stayed Bridge

Research purposes: The force and deformation of arch-shaped pylon structure is complex, so construction control is the key to ensure the bridge alignment. Relying on the arch-shaped pylon cable-stayed bridge of Yuanjiang extra-large bridge, the finite element model of the whole bridge is established. Firstly, the vertical rotation condition of the arch-shaped pylon is simulated using trial and error method, on the basis of it, the alignment and force of the arch-shaped pylon during the construction process under the two closure schemes of incremental launching and non-incremental launching are discussed. Research conclusions:(1) The arch-shaped pylon can balance the influence of self-weight by overturning 0.007 43 rad in swivel construction. After iteration, the arch-shaped pylon alignment under the two closure schemes can be closed, and the deviation from the design alignment is within 1 mm. The bending moment and maximum stress of the arch-shaped pylon in the non-incremental launching scheme after closing is obviously greater than that in the incremental launching scheme. (2) Under the two schemes, the maximum horizontal and vertical deviation between the manufacturing and design alignment of the arch-shaped pylon are 190.38 mm, 162.49 mm and -36.74 mm, 36.44 mm, respectively. Under the incremental launching scheme, the manufacturing alignment of the arch-shaped pylon is closer to the design alignment. (3) Under the scheme of non-incremental launching and incremental launching, the maximum bending moment of arch-shaped pylon is -60 420 kN•m, -44 452 kN•m, and the most unfavorable stress on the upper and lower edges of the arch-shaped pylon is -94.5 MPa, -176.0 MPa and -114.0 MPa, -148.0 MPa. In the incremental launching scheme, the arch-shaped pylon is basically under compression, the stress on the upper and lower edges is relatively uniform, and the force of the arch-shaped pylon is more reasonable. (4) The research results can provide reference for the construction and control of similar arch-shaped pylons. © 2021, Editorial Department of Journal of Railway Engineering Society. All right reserved.