Deep Hard Rock Under High Stress Unloading Rheological And Mechanical Properties Research

Due to the complexity of rock storage conditions and the composition of rocks have notable rheological characteristic. Increasing the depth of the underground engineering, the stability of rock mass under high stress become the new research urgently to discuss the problem. This paper mainly studies based on the Hongtoushan Copper Mine of 27 stope wall rock in the gneiss, whose deformation law after unloading damage with the time. Due to the deep underground mining has the characteristics such as high stress, large buried depth, and the rheological and mechanical properties of rock cavern surrounding rock after excavation of the complex, based on this phenomenon, to carry out the indoor experimental research work. Research of gneiss instantaneous deformation and long-term rheological deformation law, and chooses rock rheological constitutive model of mechanical properties, and fitting the test data. Overall, the article research content for the following:(1) The Hongtoushan Copper Mine of 27(underground 1137m) stope wall rock take gneiss, made into ? 50 mm × 100 mm standard sample. Based on the conventional triaxial test for rock strength curve, analysis of gneiss deformation characteristics. By studying the conventional rheological test stress path to design hard rock in unloading damage rheology test of stress path, and through short-term strength of rheological test to find close to failure curve of stress path which is specific grading loading, unloading and after unloading damage grading loading, and this stress path to provide basic basis of the hard rock unloading damage rheological test.(2) Using adaptive multiple field coupling triaxial test apparatus, to carry on gneiss unloading damage rheology test, and detailed investigation the classification after the loading, unloading and unloading damage grading loading stress path of axial deformation and lateral deformation, creep rate change rule and obtain rocks under the stress path in above three stages of the relationship between creep rate and stress pattern, which provides the reliable basis for the constitutive model.(3) According to the classification after the loading, unloading and unloading damage grading loading stress path under long-term hard rock rheological test curve characteristics to analyze the rheological model of rock, and selects the viscoelastic generalized Kelvin model and Burgers model, and using L-M and UGO joint algorithm for model parameter identification, and verify the rationality of the model.