砂岩蠕变损伤模型特性.

In order to study the creep damage characteristics of sandstone, the TAW-2000 electro-hydraulic servo controlled rock triaxial was used to carry out the graded loading creep test of sandstone samples. By introducing the Xiyuan and the Kachanov damage model, the damage creep model was established to describe the accelerated creep stage. Test results show that the under low stress loading, there are dense and closure of the phenomenon; creep properties of rock exists from low strain of strain hardening gradually turned into high stress strain softening phenomenon of fissures in the rock pressure; under the same confining pressure, rock under pressure in the steady creep stage of creep rate is higher than the low stress creep rate. The parameters of creep damage model are identified by Origin software using the Levenberg Marquardt algorithm. The test curve has a high degree of coincidence, which verifies the rationality of the established creep damage model and makes up for the shortcomings of the Xiyuan body that is difficult to describe the accelerated creep. [ABSTRACT FROM AUTHOR]