An innovative finite element model for tapered steel–concrete–steel powerline poles subjected to pulley–cable bi-directional lateral loading

Powerline poles are a critical component of societal infrastructure; however, they have not received sufficient research attention despite their widespread usage. This study aims to bridge this research gap by investigating the structural behaviour of full-scale tapered steel–concrete–steel (SCS) sandwich poles (Stobie Poles) under bi-directional bending induced by a pulley–cable system using a 3D finite element model. The uniqueness of this loading behaviour comes from the variation of the angle of load during the load progression. Through the validation of a finite element model (FEM) using experimental full-scale tests, various pole parameters are thoroughly analysed. These parameters include bolt diameter, pretension forces in the bolts, bolt yield strength, steel yield strength, and concrete strength's impact on pole capacity. The study evaluates the role of each parameter, revealing the negligible impact of concrete strength on pole capacity while emphasising the significant influence of the strength of the steel section. Moreover, the influence of bolt diameter, grade, or pretension force decreases beyond specific values. Detailed analyses of the structural behaviour of the poles under different biaxial bending conditions are examined, contributing valuable insights for further comprehension in this field.