Effect of Transverse Deflection on Force State of Prestressed Concrete Trough Girders with Asymmetric Cross-Section

This work aims to study the influence of transverse deflection of a beam body on pushing construction of an prestressed concrete (PC) open thin-walled beam with asymmetric cross-section and provide a reasonable deviation correction threshold for the incremental launching technique. Taking as a prototype the world’s first case of an asymmetrical cross-section trough girder—Tianjin Second Avenue Cross-Jinshan Railway Interchange Project, an actual bridge model was built using the finite element software ANSYS to study the stress state of the trough girder under the most unfavourable conditions. On this basis, using the maximum deviation distance that meets safety requirements for girder placement as the deviation limit, the influence of different transverse deflection modes on the force of the beam body was analysed. Results show that the cross-section force of the trough girder is not balanced when the deflection does not occur; however, the force imbalance is aggravated by translation to the right. When the most unfavourable transverse deflection occurs in the beam with a displacement of 96 mm, the internal force change of the trough girder is small. Therefore, it is suggested that the transverse deviation correction threshold could be relaxed to 96 mm in jacking construction.