Abstract: The small deflection theory of elastic thin plate has been used to analyze the roadway floor stress condition and the main influence factors of floor rock burst have been figured out. Theory analysis and numerical simulation have been used to study the rock burst prevention mechanism and optimization scheme about deep hole floor-break blasting and the control effect have been tested in practice. It has been found that the mining horizontal stress is the key reason for floor heave and the layer thickness of floor, and that mechanical properties and the supporting intensity of roadway surrounding rock are the main influence factors of floor heave. If the floor strata is dense thick mudstone, the rock burst will happen for the elastic deformation energy released in the process of floor layer broken. The essence of deep hole floor-break blasting is the combination of borehole pressure relief and blasting vibration method for rock burst prevention. When the position of blasting holes in the middle of the floor and roadway centre line, not only the high elastic deformation energy accumulated in the floor can be released and the ability of continuously transfer stress/ energy be destroyed, but also the high stress in the roadway side can be released, which has made the prevention effect more apparent.

Key words: floor rock burst, deep hole floor-break blasting, mining horizontal stress, floor heave