Two series test of the exposed-type column base were carried out to discuss relation of bending moment-rotation curve under variable axial force. One is subjected to axial load proportional to horizontal force and the other is proportional to beam shear force. The unbonded type anchor bolts are used for all specimens. Based on the test results, secant rigidity in elastic region of the anchor bolts and ultimate strength after yielding of anchor bolts are discussed. Finally model of bending moment-rotation curve is proposed.
