The tension of the wheel-spoke cables of the Ferris wheel runs through the entire process of the wheel flange installation and construction. Prestressed tension can be divided into two stages: the first stage of prestressed tension is the segmental assembly of wheel flange and the replacement of rigid-flexible wheel spoke. The final tension of the wheel-spoke cables after the replacement of the rigid-flexible wheel spoke is the second stage of prestressed tension.
The first stage of tension is mainly to control the deformation and internal force of the wheel flange during the process of segmental installation as well as the replacement of rigid and flexible wheel spoke. The tensile cable force of the wheel-spoke cables at this stage should be determined according to the actual installation needs on-site. After the first stage is over, install the remaining wheel-spoke cables and then perform a cable force adjustment on the wheel-spoke cables, which can make the cable force of wheel-spoke cables basically equal, finally carrying out the final tension of the second stage. The tension of the wheel-spoke cables in the second stage is the process in which the internal force of the wheel-spoke cables finally reaches the design cable force. Through the tension of this stage, the internal force of the 4 cables of the Ferris wheel will all meet the requirements of the design cable force. Due to the influence of the rigidity of the wheel flange, the subsequent tensioned cable force will have an impact on the previous tensioned cable force, so the "inverted analysis method" is used to determine the tension of the corresponding cable during this stage.
When the wheel-spoke cables are tensioned in the second stage, it is difficult to achieve simultaneous tension of 48 cables at the same time. Therefore, a new prestressed tension method "low-position fixed-point one-cycle tension method" is proposed. That is, several cables at the lowest position of the wheel flange are selected for simultaneous multi-cycle tension at the same time, which can ensure that all Ferris wheel spoke cables are tensioned at the same standard position, also, it is very convenient for construction.
In the process of each tension, corresponding cable force monitoring equipment, as well as tension and elongation monitoring devices, are set in order to ensure that the tensioning force and elongation values of the cables can finally meet the design requirements, besides, the pressure sensor method and the magnetic flux method can be used to detect the cable force.