Abstract
There are a number of examples of viaduct and normal bridge damaged seriously by fire accident in Japan, USA and other countries. Some of those bridges were fallen down by fire attack and self-weight of bridge. For these reasons, it is pointed out that the fire design for bridges should not be obligated in the design codes in such countries. For designing of steel concrete composite girder, the safety under the action of the normal force, shearing force, bending moment and their combination shall be confirmed at high temperature state. Therefore, in this paper, the interaction equations between bending moment (M) and shearing force (Q), normal compressive force (N) and bending moment (M), and N-Q-M are discussed and numerical results are reported.
