Temperature-controlled triaxial compression/creep test device for thermodynamic properties of soft sedimentary rock and corresponding theoretical prediction

In deep geological disposal of high-level nuclear waste, one of the most important subjects is to estimate long-term stability and strength of host rock under high temperature conditions caused by radioactive decay of the waste. In this paper, some experimental researches on the thermo-mechanical characteristics of soft sedimentary rock have been presented. For this reason, a new temperature-controlled triaxial compression and creep test device, operated automatically by a computer-controlled system, whose control software has been developed by the authors, was developed to conduct the thermo-mechanical tests in different thermal loading paths, including an isothermal path. The new device is proved to be able to conduct typical thermo-mechanical element tests for soft rock. The test device and the related testing method were introduced in detail. Finally, some test results have been simulated with a thermo-elasto-viscoplastic model that was also developed by the authors.