A method and system for predicting a surrounding rock instability mode of a large-span cavern based on discrete elements

Abstract

The present application relates to the technical field of surrounding rock stability analysis, and specifically discloses a method and system for predicting the instability mode of surrounding rock of a large-span cavern based on discrete elements, which comprises the following steps: establishing a structural plane network mapping dataset, constructing a multi-scale discrete element initial model and excavating in steps, identifying the symbiotic structure of stress arch shell and damage core and the three-state transition, and outputting the symbiotic structure evolution data and the structural plane state transition sequence data; tracking the stability degradation index of the symbiotic structure, performing joint reduction of joint stiffness and strength under the triggering condition, and identifying the critical reduction coefficient combination; determining the mechanical seepage threshold and identifying the instability starting area, deducing the instability chain transmission path, dividing the instability mode partition, and correcting the instability mode with the chain transmission path; and the system comprises functionally matched modules. The present application realizes the dynamic prediction of the instability mode from the aspects of stress arch shell-damage core symbiotic evolution, double-parameter reduction critical identification, and seepage chain deduction.