抄録
In concrete filled tubular columns, the mechanism of stress transsmision between the steel tube and concrete has not been clarified. Therefore it is common to attach mechanical stoppers to the inside of the tube. Firstly, we investigated the bearing strength of concrete and backing rings for tubular columns and approximated the ultimate strength. Secondly, we estimated the yield strength (1Py), displacement (1δ) and bearing spring (K) on the surface of one ring whih was weldedinside the column. Finally, we could estimate the yield strength (2Py) and displacement (2δ) by using (1Py) and (K) incase of two rings.
