An anchor-bolt-yield-type column base shows slip-type restoring force characteristics. The column
base subjected to constant axial and cyclic horizontal forces shows more complicated characteristics.
An experimental study on the column bases under constant axial force and cyclic bending was carried
out. The following conclusions were obtained from the loading tests:
1) Three types of resistant mechanisms of the column base under constant axial force were classified
to evaluate the strength and the elastic rotational stiffness of the specimens.
2) In case of axial tension N＝0.2Ny, the restoring force characteristics are the same curves as
non-axial force ones.
3) In case of axial tension N＝0.5Ny, the restoring force characteristics of the column base were
obtained by combining all types of the resistant mechanisms.
4) In case of axial tension N＝0.7Ny, the restoring force characteristics perfectly became elastoplastic
curves without slip behavior.