Experimental study about the exposed type column base using special anchor bold with upset threaded parts, which guarantee the full plastificatk n of the shank. Test results shows that this type of column basepelf well until large plastic deformation (dry angle of the column ≅1/25). After this loading the nuts wererelightened and additional loading cntinued At this stage the ookamn base behaved well again. From the test results of cyclic loading tests using four full size specimens, it becomes clear that the statical characteristics of this exposed-type of column base with special anchor bolts are slip models but those stiffness, yield strength and plastic defomlation rapacity are priate. The statical characteristics of this type column base after repair by retightening of nuts are also good. It means that this type of exposed-column bases have good repairable ability after earthquake damage.
