Uniform Pin-based Crane Columns, Effective Lengths

A parametric computer study is used to investigate the buckling of pin-based rectangular frames containing uniform crane columns. The study showed that the effective length factor of the lower segment of the heavily loaded column could be related to the nominal effective length factor obtained from the standard alignment chart. Easy-to-use formulae are presented and the K-factors for the other column segments are calculated from the heavily loaded segment. An approximate frame, in which the beam is lowered to the level of the crane, was also investigated but gave results that were not consistent enough for design use. The proposed procedure is illustrated with a numerical example.