Method for reinforcing roadway floor by grouting

The invention discloses a method for reinforcing a roadway floor by grouting in the way that the roadway floor is buried before the grouting, which is suitable for supporting projects of roadways in coal mines. The method comprises the following steps of: excavating the roadway floor during the excavation of a roadway to form a reverse arch; constructing a plurality of grouting drill holes at equal intervals along the section of the reverse arch perpendicular to the camber lines of the reverse arch respectively; arranging a special grouting tube with a hose for the floor in the grouting drill hole; filling the bottom of the arch with crushed waste rocks or cement and ensuring that the outer end head of the grouting hose is exposed from the plane of the floor; after the excavated working surface moves forwards for a certain distance, guniting and sealing the floor; and performing grouting operation on each pre-buried grouting tube through the grouting hose by connecting the exposed grouting hose with a grouting pump. The method not only avoids the reverse arch during secondary excavation of the floor, but also solves the problem that the grouting construction is interactional with the construction of the excavation working surface; the pre-buried grouting tube is easy to protect and the exposed part of the grouting tube after the grouting is easy to process; and the method can obviously improve the grouting depth, increase the bearing range for the loose and crushed rock stratum of the floor and improve the deformation resistance capacity of the floor .