Columns in multi-storey buildings
Multi-storey columns are generally restrained at every floor level, and the effective length is therefore based on storey height.
In multi-storey frame buildings the columns are restrained by the floor beams framing in at each storey. It is therefore storey height and not overall building height which is significant in determining effective lengths. Thus the column length between floors should be considered and restraints in both the xx and yy directions are to be considered in arriving at the appropriate value of the effective length LE. A practical column in a building has many restraints offered by various building components working in unison. Their overall effect cannot be accurately measured. A guess based on experience is the only possibility, and in that, the BS 5950 recommendations provide safe and sensible values for calculation of the strength of columns.
