Experimental study on double-cycle grouting reinforcement of loose and fractured surrounding rock

In order to solve the problem of continuous deformation of loose and fractured surrounding rock roadways, the field investigation and theoretical analysis methods were used to study the deformation mechanism of loose and fractured surrounding rock roadways, and the grouting scheme and parameters were proposed in combination with numerical simulation methods. After the field test, the original grouting scheme was optimized into a double-cycle grouting reinforcement scheme with a single row of 5 holes geometrical arrangement.The results show that:the double-cycle grouting scheme with grouting pressure of 6 MPa, drilling depth of 3 m, row spacing of 3 m and geometric arrangement of 5 holes in a single row can effectively reduce the probability of the occurrence of channeling and plugging, and make the slurry evenly distributed. After expanding the roadway in the grouting reinforcement section, it can be clearly observed that the diffusion radius of the slurry reaches 2.5 m, and a good skeleton structure is formed, which effectively improves the bearing capacity of loose and fractured surrounding rocks.