Design and Application of Mechanical Anchoring Device of Full Pre-stressed Bolt

Aiming at screw steel bolt which is widely used in underground engineering and has some disadvantages such as low pre-tension and short pre-stressed area,the author designed mechanical anchoring device.It improved obviously the length of pre-stressed and pre-stressed,which can effectively solv the problem of cyclic loosing pallet by explosion or rock behavior.After our testing and locale application,the results indicated that it can well adapt for bad rock conditions.