夾炭層砂岩の撓みの時間効果について
1953 年 69 巻 781 号 p. 249-252
詳細
1953 年 69 巻 781 号 p. 249-252
The specimens of “Iwwaki” sandstone brought from the Joban Colliery were used in this experiment. Each specimen, formed rectangular prism, was loaded at the penter point of its span riding on two knife edges, and after the loading the ancount of the deflection was observed during 300 hrs.
Then one of the main results obtained was as follows.
Although the stress was not reached to the max. stress equivalent to the bending strength but nearly closed to it, say 80% or over, the breakage happened within 300 hrs, if the loading was continued.
And the author tried to introduce the consideration as a relaxation phenomena for this study.
