Reliability Analysis of the 500 kV HV Transmission Steel Tower Consideing the Foundation Settlement

Taking a 500 kV Zhang-en transmission line with geological hazards as research object,and the leg settlement and the random wind as impact factors,the reliability of tower-line system was analyzed based on the moment method. The beam element and catenary cable element were used to model the transmission tower,conductors and insulators,and a 3D finite element model( FEM) of the tower-line coupling system was established. The first 4-order statistical moment was solved with using statistical moment point estimate method; the reliability was obtained based on a random equivalent static wind load model. The results indicate that the leg settlement greatly influences on the tower reliability,especially considering the random wind as the unfavorable load combination,the tower structure is with lower reliability and show s the axial compression failure and the eccentric compression failure,which is in accordance to the members failure mode of strain tower. The results verify the feasibility of the reliability analysis method. Therefore,in the practical transmission lines,the uncertainty of the tower stress due to the load random and variation resulting from the geological hazards should be deeply investigated,combined with the deformation monitoring of transmission line, which can more correctly describe the reliability and safety of transmission line structure system.