FEASIBILITY RESEARCH OF FURTHER REINFORCEMENT PROGRAM FOR NO.14 SHAFT IN JINCHUAN NO.2 MINE AREA

After the No.14 shaft was repaired in Jinchuan No.2 mine,two big cracks were formed in the new shaft well.Therefore,further reinforcement program was put forward on the repaired shaft.Based on GPS monitoring data of ground surface movement,this paper evaluated the feasibility of the reinforcement program of No.14 shaft by numerical simulation.The results show that the shallow reinforcement measure did not change the extent of mining impact on the shaft,and the reinforcement method did not achieve the desired effect.Then,the prestressed cable reinforcement was used for inspecting the adaptability of this strengthening program.It was further found the level and distribution of shaft wall displacement and stress did not change significantly before and after the reinforcement.This shows that only shallow reinforcement program was not effective for the shaft which located in the severely affected region of rock movement induced by underground mining.It was a useful guide for engineering design and had practical significance in mining production.Finally,further reinforcement program was suggested after considering damage reasons of No.14 shaft,problems in the former inforcement program,as well as trends of rock movement.