| This paper carried out the study on the double circuit transmission line steel pole of500kV in Canada, the line pole of MC52A was researched. The maximum linear angle of the pole was1°. Maximum design wind speed of the tower was140km/h (38.9m/s), which belonged to Hurricane. Pressure-span of the pole was315m, and its vertical-span of the pole was380m, and the loads on the pole were larger. The tower was analyzed and calculated using the finite element analysis software SAP2000and PLS-Pole, and the main pipes and crossarms were calculated and determined. The model selction and strength calculation of the new crossarm-joints for the pole were performed, and the the nonlinear finite element analysis of the joint were carried out. Finally, the full-scale test of the line pole MC52A was made, and the deflections and strains on typical points were measured. Base on the results of theoretical analyses and tests, the mechanics of pole and its joints, the strength design theory and structural measures of the steel pole were discussed. The main works in this paper were following:1) Crossarm-joint-the new welded I-shape steel jointDue to the lager moments and shear forces in the end of the crossarm, the new welded I-shape steel joint was adopted for the the main tube-crossarm joints. The load-defromation relationship, stress distribution and its development, deformation characteristics, failure modes were analyzed using the FEA software ANSYS. The factors affected on the bearing capacity and failure modes were investigated, such as the cantilever-width and section forms of the main pipe. The results showed that the capacity of the main pipe with round were nearly higher30-40kN than the main pipe with16-sided polygon in the same cantilever-width case. However, the ultimate and yield bearing capacity of crossarm joints were not significantly improved, with the increase of the the cantilever-width for crossarm, when the cantilever-width was more than150mm. Therefore, the cantilever-width of joints plates for steel pole MC52A with16-sided polygon adopted150mm, and the crossarm joints can satisfy with the strength requirements with good economy.2) The theoretical analyses and design of steel poleThe slip joints were adopted for the main pipe of steel pole MC52A, which had some advantages such as the simple structural measures and high fabrication precision, easy assembly, and saving material. The connections of main pipe and crossarm used the new crossarm-joint, and the I-shape sheel joint connected with the main pipes using bolts. The analysis model of steel pole for MC52A was established using SAP2000, and the yield and ultimate strengths of steel GR65were450MPa and500MPa. According to the analytical moments, axial and shear forces, the strength calculation of the main pipes and crossarms (the section forms of main pipe and crossarm were regular16-gon and octagon, respectively). Moreover, the software PLS-Pole was used to model the pole MC52A and analyze the internal forces, and finally the check analyses were made.3) Full-scale test of the steel poel MC52AIt is very rare to use steel pole for500kV transmission line all the world. The height and its loads of MC52A were very lager, and the dimensions of main pipes, crossarms and joints were very large too. In order to verify the reliability and rationality of the design, the full-scale test of MC52A was carried out, which included11different loadcases, such as the wind, anchor-wire, broken wire, and so on, and and the behavior of load-deflection and load-strain were measured and studied, and the strength and stiffness of the testing tower could well meet the design requirement with a certain safety margin.. Based on the tests and simulation analyses, the stress and deformation behavior were investigated, and the design suggetions were provided. Besides, the results from tests and analyses had good agreement, and the top deflection on the top of the steel pole could well meet the requirements in technique specifications.Lastly, the researches of this dissertation were summarized, and the design methods on steel pole, crossarm and its joint were reasonable and reliable, and can be referred for the other projects. Besides, the problems to be solved were provided. |
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