Study On Creep Behavior And Nonliner Creep Constitutive Model Of Redbed Rock

With the rapid development of construction in our country, the scale of transportation infrastructure is expanding day by day. The red beds are widely distributed in the southwest of China, and the geological and mechanical properties are complex. These large-scale construction have longer period of service. In order to ensure the safety of the operation period and predict its long-term stability, it is necessary to carry out experimental research on rheological mechanics of rock slope. As a front subject of rock mechanics, the rock rheology theory has gained many achievements in recent years. However, the study on rheological properties and rheological constitutive model of rock is still not mature enough. Based on this, this paper uses experimental research, theoretical analysis, numerical simulation method to carry out the work of the following aspects.(1) Through uniaxial compression test and uniaxial compression creep test, the rheological behavior of rock under different lithology, stress path and water content was analyzed, and the long-term strength of rock was determined. The phenomena of macroscopic rheological fracture and the development mechanism of microscopic rheology were discussed deeply.(2) According to the experimental results, three kinds of new nonlinear rheological constitutive models were established. Based on the genetic creep theory, the exponential function was used as the kernel function. Hyperbolic function was stress-strain constitutive relation, and a new empirical rheological constitutive model was established. A new nonlinear viscous element was proposed, which introduces the nonlinear components such as plastic cranny body, and a new constitutive model was established. Based on the mechanism of rock damage, the aging damage evolution equation was established, and a new rheological damage constitutive model was established. The fitting curves of the three models were in good agreement with the experimental results.(3) The three-dimensional simulation was conducted for the rock bedded slope in Yelang River Bridge. The slope deformation and stress changes were obtained in the case of instantaneous state and rheological state. The numerical results were analyzed and the reasonable engineering suggestions were given.