Excerpt from Compressive Tests of Jointed H-Section Steel Columns

The vertical members of steel-frame buildings consist of columns the length of which is usually equal to the height of two stories of the building. The ends of these columns are finished in a milling machine. When in place in the structure, the end of the upper column bears directly upon the end of the lower column. The ends of the columns are usually held in alignment by splice plates which extend across the joint and are riveted to both the upper and the lower columns. These splice plates, however, are not designed to carry any portion of the compressive load. At each floor level loads are transferred from the floor to the columns so that the lower columns carry greater loads than the upper and usually, therefore, have a greater cross-sectional area. Where columns having an H-shaped cross section are used, it is desirable to have the same depth of section for the upper and lower columns. The greater cross-sectional area of the lower column is therefore obtained by selecting a section of the same depth as the upper column, but having a thicker web and wider flanges. The web and flanges of the upper column are then supported by the corresponding parts1 of the lower column and the distribution of stress at the joint is slmp e.

In tall buildings the loads on the lower part of the building may be so great that to obtain the required cross-sectional area, the columns in the lower part of. The building must be of a greater depth than those in the upper part. At joints between columns of different depths, the flanges of the upper column are not supported by the flanges of the lower column. The axes of the interior columns are usually placed in line. The flanges of the upper column are then not in line with those of the lower column. For exterior columns the outside faces of one flange of the upper and of the lower column are usually in the same plane. The inside flange of the upper column is then not supported by the msida flange of the lower column. If the web of the upper column 1s thicker than the web of the lower column it is not fully supported. These two arrangements of upper and lower columns are shown in Figure 1.

About the Publisher

Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com

This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.