Research on Cast Steel Joints Used in a 385-Meter Super Long-Span Transmission Tower Crossing the Yangtze River

In view of the characteristics of many member intersections, complex spatial relations and special load conditions at the connection joint of cross arm and main rods in a 385-meter super long-span transmission tower crossing the Yangtze River, which is a national key project, cast steel joints were proposed to applied in the transmission tower for the first time. Considering the characteristics of complex shape and high importance of cast steel joints, two 1∶2 scaled models of joints were designed and the bearing capacity verification test and finite element analysis were carried out in order to verify its safety and rationality.The results showed that under the 90° gale test condition, the maximum stress location of the joint was the chamfer of the member, the strain basically changed linearly with the load, and the whole joint was in a linear elastic state. The experimental results were in good agreement with the finite element analysis results, which showed that the joint model could truly and effectively simulate the actual stress of the joint. The finite element elastic-plastic analysis results showed that the ultimate bearing capacity of the cast steel joint was 12.39 times of the design load, with a large safety redundancy, and the joint design was safe and reliable.