The column was fixed at its ends on a loading frame subjected to the axial compression ratio of 0.5 and a constant axial load of 200kN which simulated the axial force of the lower column as far as possible. Horizontal loads were imposed by force and displacement method. Each load step had two cycles back
and forth controlling by force before yielding of steel bars. While it had three times per cycle in amplitude level controlled by the displacement after yielding and then increased the load point displacement into the next load.