Column base structure

Abstract

A column base structure is provided that is capable of enhancing the energy absorption capability of the column base structure, thereby preventing the building structure from being damaged, broken and collapsed, and also preventing the column base structure and the building structure from being increased in size, weight and cost. The column base structure contains a junction fitting 42 joined to a lower end of a column member 4, the junction fitting 42 being fixed in a peripheral portion thereof with an anchor bolt 10 that protrudes upward from foundation concrete 3, the anchor bolt 10 yielding before the column member 4, a first bending moment Ma that initiates yield of the anchor bolt 10 being larger than a second bending moment Mb that initiates yield of the peripheral portion of the junction fitting 42, and being 1.5 times or less the second bending moment Mb.

What is claimed is: 
     
         1 . A column base structure comprising:
 a junction fitting having a peripheral portion;   a column member having a lower end;   a foundation concrete;   an anchor bolt protruding upward from the foundation concrete; and   the column base structure being structured such that the peripheral portion of the junction fitting joined to the lower end of the column member is fixed by the anchor bolt, and the anchor bolt yields before the column member,   wherein a first bending moment that initiates yield of the anchor bolt is set to be larger than a second bending moment that initiates yield of the peripheral portion of the junction fitting, and be 1.5 times or less the second bending moment.