Application of the convergence-confinement method to excavation response of roadway in rock mass considering large deformation

Abstract

For mining operations in a rock mass with high deformability and low strength, large deformation is one of the primary manifestations of roadway failure, which easily occurs when the construction techniques and support measures cannot accommodate the geological environment. Therefore, the ground response to excavation disturbance and control technology of squeezing behavior should be analyzed based on large deformation theory. This study presents an elasto-plastic theoretical model for a circular roadway in the finite strain framework using a hypoelastic-plastic theory and convergence-confinement method to provide a rigorous approach for large deformation prediction and weak rock-support interaction analysis. A novel numerical procedure for the strain-softening rock mass subjected to large deformation is proposed based on an existing brittle-plastic analytical formula, which is simple but precise. Furthermore, suggestions on analysis of weak rock-support interaction based on large deformation method are presented, which may be beneficial to understanding deformation prediction and support design more rigorously.