钢管塔塔身变坡处大多采用大板对焊式或法兰螺栓连接式2种方案连接塔身上下主管，保证传力清晰合理。对淮南—上海1 000 kV特高压交流双回路SJ276转角塔塔身变坡节点分别采用2种方案的连接方式进行了经济性和可靠性计算分析比较。结果表明，只要在设计参数取值合理的情况下，2种方案的塔身变坡节点都是安全可靠的，但是法兰螺栓连接式方案更节省塔材，塔重减轻约2％。

In order to achieve a simple structure and definite transit route of load, either weld with plate or bolts connection should be provided at the section with slope change on the main member of steel tubular tower. Taking the SJ276 tower for 1 000 kV AC double circuits transmission line from HuaiNan to ShangHai, weld with plate and bolts connection are respectively applied. The economical efficiency and security of applying two connections in the SJ276 tower are analyzed. The results indicate that the tower is safe entough under two connections, while the weight of tower can be reduced about 2% by applying bolts connection.