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During opening construction, the accumulated wall displacement and the developing excavation damaged zone are the results of stress redistribution and inelastic behavior induced by both the microcracking damage and the irreversible plastic deformation. The current approach to predict ground response to excavation disturbance is usually based on the Convergence-Confinement Method, which fails to consider the rock damage and the plastic-damage coupled mechanism, resulting in inaccurate estimation of rock deformation, particularly in the case of the weak rock with high deformability. This study establishes a plastic-damage theoretical approach for a circular opening by a kinematic decomposition of strains into an elastic, plastic and damage parts within the framework of finite strain using a hypoelastic–plastic theory, in order to investigate the inelastic behavior-induced excavation response. In this regard, the damage model provides the effective stress to the plasticity model defining the yield criterion, in combination with the strength-stiffness degradation and damage evolution. The numerical implementation is given and two examples are considered for validation. Extensive works are then carried out to clarify some issues, including the capacity of the model to characterize the inelastic behavior, the role of rock damage and confining stress dependence on ground response, and the preliminary critical support pressure for the residual failure zone., This work is funded by the National Natural Science Foundation of China (Grant Nos. 52004053, U1906208 and 52074060), Natural Science Foundation of Liaoning Province (Grant No. 2021-BS-052), and Fundamental Research Funds for the Central Universities (Grant No. N2101028). These supports are gratefully acknowledged., Peer Reviewed, Postprint (author's final draft)

The block sliding and instability process under the coupling effect of both dynamic shear loading and ultra-low friction caused by dynamic disturbance has been studied. Laboratory equipment was developed to investigate the sliding instability of an isosceles trapezoid sandstone rock block triggered by dynamic disturbance. The sliding displacement, strain, and impact energy were monitored during hammer impact under different lateral clamping load conditions. Results show that the typical vertical displacement of key blocks can be divided into three modes post-disturbance depending on the clamping load and impact energy. Two distinct instability processes (immediate falling and delayed falling) were observed once the key block began to lose stability and fall. The difference between them involves the instantaneous slide distance and pendulum-type wave propagating on the sliding interface. Based on the energy analysis, an analytical solution to key block sliding displacement under dynamic disturbance is proposed, which accounts for the influence of clamping load, disturbance energy, interface friction coefficient, and key block incline angle. By comparison with the experimental results, the theoretical calculation is shown to effectively estimate the sliding distance of the key block under dynamic disturbance., The block sliding and instability process under the coupling effect of both dynamic shear loading and ultra-low friction caused by dynamic disturbance has been studied. Laboratory equipment was developed to investigate the sliding instability of an isosceles trapezoid sandstone rock block triggered by dynamic disturbance. The sliding displacement, strain, and impact energy were monitored during hammer impact under different lateral clamping load conditions. Results show that the typical vertical displacement of key blocks can be divided into three modes post-disturbance depending on the clamping load and impact energy. Two distinct instability processes (immediate falling and delayed falling) were observed once the key block began to lose stability and fall. The difference between them involves the instantaneous slide distance and pendulum-type wave propagating on the sliding interface. Based on the energy analysis, an analytical solution to key block sliding displacement under dynamic disturbance is proposed, which accounts for the influence of clamping load, disturbance energy, interface friction coefficient, and key block incline angle. By comparison with the experimental results, the theoretical calculation is shown to effectively estimate the sliding distance of the key block under dynamic disturbance.