| Stability and security in the underground engineering has not been ignored, the deep rock mass is compelled to represent various rheological properties on different circumstances as a consequence of complexity and disturbance around the rock environment. In view of this, the study of the creep properties of the rock is a hotspot of scholars for a long time, the theory of rock creep research still remains to be improved and the current study of rock model is still a difficulty.Sandstone was selected as the object of study. Such physical parameters as density,moisture content were measured by conducting a physic-mechanical research on sandstone. X-ray diffraction test was performed in order to study and analyze its internal chemical composition. Conventional triaxial compression experiment on rock specimens under undrained and drained conditions with TAW-2000 electro-hydraulic serve rock triaxial apparatus was conducted for the purpose of obtaining cohesion, internal friction angle, compressive strength, long-term strength, yield strength and other parameters, which laid a solid basis for the creep test. The results, finally, were presented for triaxial creep comparative test on sandstone under undrained and drained conditions with different confining pressures, on the basis of which the influence of confining pressure, axial pressure and water on creep deformation, deformation mechanism and creep damage forms were analyzed.Nonlinear sticky element was added, on the basis elements so as to build a new model that can reflect the whole creep process of aqueous sandstone accurately. The model parameters were identificated, relying on origin software, by the least squares methed. The regular of the fitted curve corresponded exactly with that of the measured urve, thus verifying the rationality and feasibility of the creep feature described by nonlinear creep model in the process of rock experiment, thus laying a theoretical foundation of practical engineering. |
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