Reliability-Based LRFD for Transmission Structures

A simple reliability-based Load and Resistance Factor Design (LRFD) method is proposed for the structural design of electric transmission lines. With the proposed method, the designer is able to assign relative levels of reliability to different lines, to different structures within one line and to different components within one structure. Full implementation of the method will require statistical data on controlling limit states. Existing strength data have been studied and corresponding statistical models are proposed. It is shown that better strength data are needed, but also that engineering judgement, combined with existing data, can be used to start using the LRFD method immediately.