RELIABILITY-ANALYSIS AND FULL-SCALE TESTING OF TRANSMISSION TOWER

The new generation of reliability-based load and resistance factor des ign (LRFD) method for the design of electric transmission line structu res at member level is governed by ASCE Manual 74. Transmission towers generally comprise steel angle components. The nominal strength of th ese components, for various end conditions and slenderness ratios, is widely calculated using the design equations in ASCE Manual 52 for the reliability-based design (RED). There are known inconsistencies in th e RED of tower members using these ASCE Manuals, particularly in the c ase of members in compression. Considering these facts, the effect of buckling, joint connections, and framing eccentricities on the RED of components have been examined and limiting values of the slenderness r atio (Ur) for the compression member alone are proposed in this techni cal note. A 220-kV tangent tower has been used for full-scale testing to validate the analytical results, and a good agreement with the pred icted results indicates a definite need for an improvement of ASCE Man ual 52 and the relevant Indian standards.