## 5 Scheme and Application of Grouting Reinforcement Support  
### Implementation of Grouting Reinforcement Support Scheme  
The mining roadway of the ZF3806 working face adopts a rectangular section with a net width of 4.0 m and a net height of 3.5 m. The original support scheme was bolts and cables combined with anchor mesh and a steel belt to strengthen the support, but the effect is poor. Therefore, to ensure the mining face's safe and efficient mining and improve the mining roadway's stability, based on the original support scheme, a reinforcement support method with layered grouting of \"shallow bolt + deep cable\" as the core is proposed.  
1. Bolt support parameters: As shown in Figure 10, the roadway roof adopts a \(\varphi\) 20 mm \(\times\) 2200 mm equal strength threaded steel resin bolt and the row spacing of 0.9 m \(\times\) 1 m. The arch-type high-strength pallet is adopted, and the specification is 150 mm \(\times\) 150 mm \(\times\) 10 mm. The extended anchoring method is adopted, and the anchoring length of the bolt is 1050 mm. A W-shaped steel belt support is combined, and a diamond-shaped metal mesh is hung on the whole section with a mesh size of 50 mm \(\times\) 50 mm. The two sides are arranged with a \(\varphi\) 20 mm \(\times\) 2200 mm bolt with a row spacing of 1.3 m \(\times\) 1 m.
2. Cable support parameters: As shown in Figure 10, the roadway roof adopts a \(\varphi\) 22 mm \(\times\) 6300 mm hollow grouting cable arranged in a \"well type\" form with anchor support. The row spacing of the cable is 1.5 m, and the cable is perpendicular to the roof. The distance between the upper side cable of the roof and the upper side is 0.3 m, the distance between the middle cable and the upper side is 1.55 m, and the distance between the lower side cable and the lower side is 0.65 m. The anchoring length of the cable is 1300 mm. The cable is supported by a three-hole steel belt, and the stubble is arranged between steel belts.
3. Layered grouting reinforcement support: A layered grouting reinforcement support design is implemented for the roadway roof. The \"shallow bolt grouting\" is based on the original bolt support. The hole depth is 2 m, the grouting holes are located between every two rows of anchor bolts, and the row spacing between grouting holes is 1.8 m \(\times\) 2 m. When grouting, the borehole shall be used with the grout stop sleeve to make the borehole pass through the fracture zone vertically as far as possible and maximize the diffusion of grouting fluid. The \"deep cable grouting\" adopts continuous downward grouting carried out in sequence along the roadway. When the design grouting pressure is 10 MPa, the pressure is stabilized for more than 10 min so the grout can spread to the maximum range and the roof rock cracks can be filled as much as possible. The \"deep anchor cable grouting\" material is superfine cement, and the \"shallow anchor bolt grouting\" material is GRPC-1 early setting and early strength new material. The \"shallow\" grouting shall be carried out first and then the \"deep\" grouting. In the process of \"shallow\" grouting when there are abnormal phenomena, such as slurry channeling on the surrounding coal wall, the grouting pump shall be stopped in time.