Shigen-to-sozai, Vol.118, No.1, pp.43-48.
Long-Term Creep Test and Constitutive Equation of Tage Tuff
Seisuke OKUBOa and Katsunori FUKUIa
| a. Department of Geosystem Engineering, The University of Tokyo |
| Two long-term creep tests of Tage tuff were
carried out as long as three years. In the
tests, specimens were submerged under the
water, and creep stress was applied and maintained
at 30% of the peak strength. The first one ~vas started in 1994. The result indicated that creep strain rate was monotonically decreasing with elapsed time approximately proportional to (elapsed time)-09. Through the testing period, creep strain was increasing approximately following (elapsed time)0.1 and did not reach the creep limit to which creep strain leveled off. The second one was started in 1997 and the result was similar to the first one except that creep strain was slightly smaller than the first. A constitutive equation of variable compliance type was modified especially focusing on the long-term creep at low stress level. Experimental results of not only this study but also previous studies were carefully examined. It was found that the creep strain and strain rate calculated by the modified equation reasonably well coincided with the experimental results. |
| KEY WORDS: Rock, Tuff, Creep, Long-Term Strength, Constitutive Equation, Visco-Elasticity |