ELASTOPLASTIC ANALYSIS OF SURROUNDING ROCK OF DEEP ROADWAY BASED ON ROCK CREEP AND D-P CRITERION

In order to deeply analyze the influence mechanism of rock creep and intermediate principal stress on the stability and zoning deformation characteristics of surrounding rock in deep high stress soft rock roadway, by analyzing the deformation characteristics of surrounding rock of deep roadway under long-term load, the four zones deformation mechanism of surrounding rock of deep roadway based on the creep characteristics of surrounding rock is revealed, the effects of intermediate principal stress, the rock mass expansion and the post peak strain softening characteristics are considered according to Druck-Prager criterion and correlation flow rule, and the elastic-plastic analytical solutions of stress, deformation and radius of four deformation zones of surrounding rock in deep high stress soft rock roadway are derived. Combined with the specific engineering example, through the comparative analysis of field monitoring data and calculation results obtained by using different mechanical models, the scientificity and feasibility of this theory are demonstrated, and reveals the influence law of different strength criteria and surrounding rock parameters on the zoning shape of surrounding rock in deep roadway. The results show that ignoring the creep characteristics of surrounding rock in deep high stress soft roadway will lead to the value of initial cohesion greater than the actual value, resulting in the theoretical bearing capacity of surrounding rock in deep high stress soft roadway greater than the actual bearing capacity. Increasing the intermediate principal stress coefficient in the range of 0, 0.7 can effectively control the expansion of plastic zone and broken zone of surrounding rock. When the initial cohesion and internal friction angle of surrounding rock decrease, the influence of intermediate principal stress coefficient on plastic zone, broken zone and roadway deformation of surrounding rock increases significantly. The research results can provide theoretical reference for underground engineering support design and surrounding rock stability evaluation.