THE UNIAXIAL MECHANICAL PERFORMANCE TEST AND CREEP MODEL OF ARTIFICIAL FROZEN DEEP SOFT ROCK

In order to understand the uniaxial mechanical performance of the deep soft rock under the frozen condition, the undisturbed pelitic sandstone from northeast of China is taken for test. The uniaxial compressive strength test and the uniaxial creep experiment for the artificial frozen pelitic sandstone are performed by using the self-developed artificial soil test instrument of WDT-100 type, and the stress-strain curve of the mud-sandstone, the uniaxial compressive strength at different temperatures, and the creep duration curve are obtained. The uniaxial compressive strength test shows that the stress-strain curve has an obvious yield point, and shows hardening phenomenon. The uniaxial creep experiment shows that the creep duration curve has nonlinear characteristics, the isochronous stress-strain curves are deviated to the strain axis, and the uniaxial compression creep modulus decreases with time, then tends to be stable over time. Finally the empirical formula is obtained by using a genetic algorithm to optimize model parameters. Compared with the results of test, the agreement is good.