Based on the long-span transmission tower of 500 kV Fengcheng to Meili project, the selection of the joint of bottom-crossarm compression members was conducted. Three types of joints were put forward and compared, including tubular welding joint, welded hollow spherical joint and cast steel tubular joint. Monolithic casting technique was adopted in cast steel joints, it could solve the problem of space intersection of multiple members, and avoid complex welding process. Based on the comparison results, the cast steel joint was selected, and the steel material was G20Mn5QT. Then, the nonlinear finite element analysis was performed, the stress characteristics and ultimate bearing capacity of the cast steel joint were investigated, and the design bearing capacity of the joint under different load cases was calculated. The resules showed that the cast steel joint was safe and reliable, which could be wildly used in super high-rise transmission towers.
LI B H, ZHANG D C, CAO P Z, et al. Experimental research on dynamic tensile behavior of full-scale welded-necked flange joints used in transmission steel tubular towers[J]. Journal of Vibroengineering,2018,20(3):1274-1287.