Abstract:

The action mechanism of low-grade backfill with three kinds of different filling height on the stability of mining environment structure was analyzed by ADINA finite element analysis code. The results show that the stability of a layer structure with the increasing of filling height has some rules as follows. (1) The highest value of tension stress of artificial top pillar decreases gradually, and stress conditions has been improved. (2) The tension stress status in artificial pillar transforms into the compressive stress status, and the value of compressive increases gradually; and the carrying capacity has been improved gradually; however the filling height is beyond a certain height, the carrying capacity of the artificial pillar grows very slowly; and It is not too much significance to improve the carrying capacity only by the action of low-grade backfill. (3) The squeezing action on the artificial bottom pillar from artificial pillar transforms to the artificial bottom pillar into gravity action from the low-grade backfill, the largest value of tension stress of the artificial bottom pillar appeares the change rule that increasing at the beginning then reducing. Considering the economic, security and other factors, low-grade backfill has the most reasonable height (2.8 m) in the filling scope. This study provides the basis foundation for the safety construction of the mining environment reconstruction structure.

Key words: low-grade backfill, cataclastic ore section, mining environment reconstruction, structure stability, action mechanism