Study on mechanics and domino effect of large-scale goaf cave-in

A large area of continuous solid shallow-buried goaf group created by open-stope method, under the influence of space–time effects exerted by slow creep of the pillar–roof system, will wholly collapse driven by partly instability of pillar and roof collapse until the whole mine collapses, showing a domino effect. The dynamic process is ignored in the traditional analysis of mechanical stability. Based on analysis for the domino effect and disaster-relief mechanism in the mining goaf, the mechanical method combined with Voronoi graph method has been adopted to establish the dynamic analysis on the pillar–roof system stability. It seems more in line with the actual situations, and can help to more accurately predict the time and location of disaster. The conclusion is of great value on study of rock mechanics and mining companies’ safety production.

► We find a domino effect of collapsing pillar-roof system caused by space–time effect.
► We analyze the domino effect and the disaster-relief mechanism in the mining goaf.
► Dynamic analysis on the goaf is established with mechanical and Voronoi graph method.
► Increasing the overall aspect ratio of pillar to enhance the safety reservation.
► Distributing protection pillar evenly to cut off the spread of instability.