Abstract:

The SZ2U tubular steel tower, 103.6 m in height and 132 tons in weight, and made of the Q460 high-strength steel, is a full-scale testing tower applied in 1 000 kV UHV AC double-circuit transmission line project. The test was carried out according to the standard DL/T 899—2004“Loading Tests on Tower and Pole Structures of Overhead Line”under 8 different operation conditions, including wind, anchor-wire, broken wire,and so on. The testing results show that the actual displacement and stress of the tower SZ2U are within the limits of deformation and member’s bearing capacity respectively; the strength and stiffness of the testing tower meet the design requirement with a certain safety margin, and the joint construction and flange connection are reliable. Application of the Q460 high-strength steel in UHV transmission tower design can not only meet the requirement of design code, but also reduces the weight of the transmission towers. It is therefore recommended to use it through pilot projects. In addition, the secondary moment of the tower’s primary members is measured during the full-scale test. A comparison of the measured result and the theoretical values indicates that the effect of secondary moment of the primary members under the varying slope is prominent, and it is therefore recommended to establish the finite element model, the finite element model of node rigidity if necessity, to check the strength.