A New Method for Disposal of Abandoned Mine Stopes——The Technique Local Grooving Top-caving with Controlled Explosion

摘要

After 12 years large-scale mining, 430000m2 oontinous and gently inclined atandoned-stopes were formed underground in Dongtongyu Gold Mine. To prevent hidden danger of air shock wave resulted by roof sudden-caving of the roof, a new unified method, local grooving top-caving with controlled explosion, Is applied to dispose abandoned-stopes. In this paper, the characteristics of the method, location, width and depth of grooving are introduced simply, and the calculated grooving location is validated by two-dimensional finite element method (FEM). Meanwhile the effective cutting roof is evaluated by two-dimensional FEM. three-dimensional ANSYS, the acoustic emission (AE) monitoring in the roof of level tunnel and photography in the disposed abandoned-stope. The results show that the cutting roof nearby 866m and 966m levels is reasonable when ore above 750m level is mined entirely, and the roof stress will redistribute to more safe situation, and obvious surface subsidence and rock movement can be prevented. Under many the roof may fall and fill the abandoned-stopes soon after its roof cutting is conducted, whereas, under many circumstances the roof must experience one or two months then falls and fills the abandoned-stopes. Moreover, the hidden danger of large scale roof sudden falling is eliminated.