Abstract: Harnessing floor heave of roadway is one of the difficult but key problems in roadway supporting. The influence factors and mechanism of floor heave in the deep soft-engineering rock roadway are analyzed through site investigations and monitoring in the middle-strip track roadway at Xinjing Coal Mine. It is confirmed that the main causes of floor heave are that there is no support in the floor rock，which means the shear failure occurs firstly because of high-stress，and then stratum crushes further into squeezing and flowing because of water leading to further fragmentation. Therefore，the mechanism of the continuous “double shell” harnessing floor heave is studied by using continuous “double shell” to control floor heave and the technique of the continuous “double shell” harnessing floor heave that uses “bottom shallow hole grouting (shallow shell) +deep-anchor-beam with high-pressure grouting (deep shell)”to control floor heave is established. The technique has obtained a good effect.

Key words: deep roadway；soft-engineering rock；harnessing floor heave；continuous &ldquo, double shell&rdquo, ；support mechanism