| series of rock engineering activities is bound to affect or broke n the rockmass stress balance, causing the redistribution of the ground str ess. If the second ground stress can not be reasonably controlled and utilized, the rock mass will inevitably resulted in instability,displacement,collapse and a series of repairable damage. Everything has its two sides. From a dialectical perspective, high stress can induced disasters, can also be properly utilized for the rock breaking. For the problem of high ground stress induced fracture, this paper made the following research:(1) According to the rock unloading failure regularity and characteristics, using fracture mechanics theory, the rock depth of damage and the extent of damage were deduced under secondary excavation of broken.(2) Analysis of the roof instability of the structure and mechanical characteristics, combined with ore and rock blasting fracturing technique, ore-bearing rock is put forward to the blasting and caving induced crack caving mining method. The induced crack of surrounding rock caving of the three basic conditions:damage condition, airport surface conditions and equilibrium conditions are inductive.(3) On the basis of the induced crack caving mining idea, more segmented induced crack caving mining plan was designed. Through the simulation of design plan of mining sequence and excavation, the conclusions were discovered. artificially adjusting the mining sequence of upper and lower layers ore block can control the direction of concentrated stress. This concentrated stress is used to pre break crock as preliminary destructive power.(4) This paper organized the construction of the mining program. It achieved good results by arranging the mining sequence in upper and lower layers, transferring concentrated stress through artificial control, using the blasting technology of induction to fracture and controlling the nugget avalanching naturally. It saved mining costs greatly and improved mine production efficiency. |
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