The Structural Engineer > Archive > Volume 7 (1929) > Issues > Issue 5 > Correspondence Wind Bracing in Structural Frames
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Correspondence Wind Bracing in Structural Frames

To the Editor, “ The Structural Engineer.” Dear Sir,-It has been a long time since the writer has read any papers with greater interest than Mr. Hakin’s "Wind Bracing in Structural Frames" in your December, 1928, issue and the discussion thereon in the February, 1929, issue. His own latest thought is embodied in an article, "Wind Stresses in Many-Storied Buildings," in "Engineering," issue of May 25, 1928. Two methods of calculation are there presented : the “cantilever” method and the “portal” method. (Let it here be stated that the writer sponsors these methods; he did not originate them.) The cantilever method, in which direct stresses in columns due to lateral wind pressure are proportional to their distance from the neutral axis, is evidently preferred by one of your correspondents. This method has much in its favour. Incidentally, in the unique 33-story Foshay Tower at Minneapolis, Minnesota, described in the current issue (March 7, 1929) of the “Engineering News-Record" the wind stresses were calculated in accordance with the cantilever method. While this method may be more in accordance with the theoretical distribution of stresses, the portal method is simpler and duplicates more connections. A few years ago the writer designed with great care a 20-story buildmg in accordance with the cantilever method. He later found that the working drawings showed all end connections of girders in the same floor to be alike. The detailer had taken the average of the bending moments of a floor and designed his connection accordingly. This gave connections and stresses more in accordance with the portal method than with the cantilever method.