This paper discusses the high-cycle fatigue properties of box section steel column members with the partial penetration groove welded joints. High-cycle bending fatigue tests of the column members are carried out. The summaries of the results are shown below. There are two fracture types; one is the type of fracture at the column-to-column joints and other is the type of fracture at the column-to-base-plate joints. The fatigue life of the column-to-base- plate joints satisfy F class of JSSC fatigue design curve, and the fatigue life of column- to-column joints satisfy H class of it. The Fatigue life of the column-to-column joints could be estimated from their fatigue crack propagation properties.
