Joint Training for Professional Collaboration in the Building Industry

Mr. R. Paul Johnson (Associate-Member) said it was remarkable how high a proportion of the tests on cased stanchions had been carried out under axial loading. We should, therefore, congratulate the author on having included eccentricity of load as a variable in his tests. But Mr. Stevens had not gone far enough. He concluded his paper by giving tentative recommendations for the ultimate strength of encased stanchions under minor axis bending and with a known eccentricity of load. That corresponded to the way in which the stanchions were tested, but it seemed to the speaker to be of limited practical use. He asked how the author intended the recommendations to be used for the design of a stanchion length in a building structure, for which eccentricity of load was the wrong parameter. The end moments in a stanchion in a building structure were rarely equal to each other, and certainly did not remain proportional to axial load as load increased.

The paper outlines the uses that can be made of ductility in reinforced concrete frames, the enhanced properties of ductile frames and the means of achieving ductility. It also treats the particular application of ductility to earthquake design and the very close relationship between the ductility of frames and ultimate methods of design. G.C. Entrican