Results of TLMRC research on X-bracing strength in lattice transmission towers

To clarify the design of tension/compression X-bracing, the common type of bracing used to resist lateral hold in transmission towers, a research program was initiated, with particular emphasis on the effect of the tension member load on the capacity of the compression member. A two-dimensional test frame was used to test X-braces constructed of equal leg angles or unequal leg angles framed either on the long leg or on short leg. Tests were performed on X-braces framed with parallel posts and on X-braces framed with battered posts. As a result of this research, a method of computing the effective slenderness ratio is recommended