Research on Rheological Disturbance Damage Laws of Rock in the Strength Limit Neighborhood

Abstract

As coal mining enters deep, the rock is close to the strength limit neighborhood, and it is extremely susceptible to deformation and damage due to disturbance. In order to study the damage evolution law of rock in the strength limit neighborhood, red sandstone is selected as the research object, and the self-developed RRTS-IV rheological disturbance experimental system and nuclear magnetic resonance test equipment are used to carry out the gradual loading test of the rock rheological disturbance effect. Through the analysis of the test results, it is concluded that the instantaneous elastic modulus damage of the rock is accelerated rapidly with the increase of the number of disturbances in the strength limit neighborhood, and the disturbance becomes proportional to the instantaneous strain of the rock. At the same time, through parameter identification of the rock rheological data under different disturbance times, the rheological damage constitutive model is established, and the test results are in good agreement with the fitted curve. This shows that the establishment of this model is reasonable, and it can reflect the damage characteristics of the rock in the strength limit neighborhood under the action of different disturbance times, and the relaxation time and the disturbance times increase exponentially