Abstract: In view of the frequent large deformation failures of the extraction roadway floor in thick seam 76#-2 in Wuyang mine，we proposed the prevention concept of medium and deep strengthening in thick seam roadway to control floor heave，through studying on the mechanism and control method of the floor heave in thick seam roadway．Additionally，the effects to the floor under different supporting ways were simulated by FLAC3D software. The results show that the floor deformation without supporting is 1.3~1.6 m，but the floor damage zone will be extended gradually under the mining stress disturbance．The floor plastic zone will be reduced correspondingly by the support of anchor coupled with the grouting，but the maximum value of floor deformation amount to 0.7~1.0 m when influenced by mining stress，and the roadway still can’t meet the production needs．By using the combined support of a branch of high-strength anchors coupled with concrete block and grouting，the plastic zone in floor surrounding rock will be reduced significantly，and the floor heave is only 0.24~0.38 m，which has met the requirements to control the floor deformation．Through the engineering tests of the combined support technique，the result shows that the two sides’displacement and floor heave of the roadway are 226 mm and 283 mm，which are reduced by 56.5% and 83.4%，respectively．Thus，the large-scale deformation of roadway floor in thick seam has been controlled effectively．

Key words:  , control of floor heave；large-scale deformation failure；grouting in medium and deep floor