Cft pillar design method of

The present invention provides a method for selecting a steel pipe suitable for a CFT (Concrete Filled Steel Tube) column used in a civil engineering structure. A design method of a CFT column using high-strength concrete as concrete to be filled in a steel pipe, and selecting a steel pipe having the highest proof strength as a CFT column from a plurality of steel pipes as the steel pipe. In the concrete column obtained by filling the high-strength concrete, the column deformation angle at which the maximum proof stress is obtained, the fracture occurs at or above the column deformation angle obtained by multiplying the column deformation angle by a safety factor among the plurality of steel pipes, and A steel pipe having the largest steel pipe end moment at the column deformation angle at which the maximum yield strength is obtained in the concrete column is selected. [Selection] Figure 1