In this paper, various frames with their spans of 20, 26, 32 and 38 m and locations built in Hanoi and Son La regions were designed to resist dead, roof live, crane and wind loads. The equivalent horizontal and vertical static earthquake loads applied on the frames were determined. Next, by using linear elastic analyses of structures, the effects of vertical seismic actions on the responses of the frames were evaluated in terms of the ratios K1 and K2 at the bottom and top of the columns corresponding to different combinations of dead loads and static earthquake loads, as denoted by CE1, CE2 and CE3. The effects of seismic actions compared with those of wind actions were also evaluated in terms of the ratios K3 and K4. | Effects of vertical seismic actions on the responses of single storey industrial steel building frames