�@ Œf�ÚŽGŽ��i˜a�j�F “ú–{’n�k�HŠwƒVƒ“ƒ|ƒWƒEƒ€˜_•¶�W Vol�F 8-2Šª ”N�F 1990”N •Å�F 1629-1633•Å ’˜ŽÒ�i˜a�j�F - ƒ^ƒCƒgƒ‹�i˜a�j�F - �´˜^�i˜a�j�F
- ƒL�[ƒ��[ƒh�i˜a�j�F - Œf�ÚŽGŽ��i‰p�j�F PROCEEDINGS OF THE JAPAN EARTHQUAKE ENGINEERING SYMPOSIUM ’˜ŽÒ�i‰p�j�F M. Ala Saadeghvaziri ƒ^ƒCƒgƒ‹�i‰p�j�F EFFECT OF AXIAL FORCE HISTORY ON THE MOMENT-CURVATURE RELATIONSHIPS FOR R/C COLUMNS �´˜^�i‰p�j�F
In the event of a major earthquake, large uncoupled axial and lateral forces can be developed in the columns of reinforced concrete (R/C) structures. The results of an analytical study on the effects of nonproportional axial load on the moment-curvature (M - �¡ ) relationship for columns is presented. The results indicate that the moment capacity of R/C columns under uncoupled variations in axial load can be significantly smaller than a case in which the axial load is constant or when the variations are proportional to changes in moment. Thus, by recognizing this effect, the seismic design of R/C structures can be upgraded to resist complex loading histories that may occur under bi-axial (or 3-D) excitations of structures during earthquake ground motions. ƒL�[ƒ��[ƒh�i‰p�j�F - ‹LŽ–‹æ•ª�F - ‹æ•ª �@�@�@ˆÏˆõ‰ï˜_•¶�W