Characteristics Comparison and Case Study of Traditional Anti-Slip Saddles and Innovative Rolling Saddles in Highway Long-Span Bridges

Abstract

The cable saddle structure is the main support component for long-span bridges to transmit cable force, which is of great significance for the structural force system. Nowadays, the main cable saddle structures used in long-span bridges are mainly traditional anti-slip saddles and innovative rolling saddles. To clarify the characteristics of the saddles in long-span bridges, the design principles, mechanical properties, and casting process of these two types of saddle structures were researched. A rolling saddle in a bridge project was taken as an example and its mechanical situation in the roller area was investigated. The results showed that the stress concentration phenomenon is prone to occurring in the rolling saddle because of the line contact in the contact area and the rolling saddle is mainly subjected to vertical force. Thus, attention should be paid to the von Mises stress in the contact area between the saddle base and the roller shaft, the lower surfaces of both ends of the roller shaft, and the top surface of the tower, to avoid material damage. Furthermore, the casting process of the anti-slip saddle structure is mature, but also faced with problems due to the welding of thick plates, and urgently needs to be improved and upgraded. The rolling saddle is used with the all-welded casting process, but its technology is relatively immature and the requirements for the roller shaft material performance are strict. The research results can provide a reference for the selection and design of the saddle structure in long-span bridges.