Computer Analysis of Tower Verified by Testing

The application of the STAIR (STructural Analysis Interpretive Routine) Computer program to the analysis of transmission towers results in a more exact stress analysis than can be accomplished by manual methods. This is particularly true because of the highly indeterminate tower configurations and the multiplicity of loading conditions. An illustration of the application of the STAIR program to the analysis of a 500 kv single circuit tangent tower is presented. Input data preparation, the STAIR system, and the interpretation of the results are treated. A description of the full-scale test facilities, tower loading, testing arrangements and procedure are given. The measured deflections are compared with the computed deflections obtained from the analysis and the discrepancies are resolved. A full-scale tower test afforded one of those rare opportunities to compare the mathematical analysis of an idealized structure with the test results for the actual physical structure.