## 6 Conclusions  
In this study, a highly deformed shallow-buried soft rock roadway in the Jiebangou coal mine was considered as the research subject. By combining field investigations, theoretical analyses, laboratory tests, numerical simulations, and field applications, the failure and instability characteristics of the surrounding rock of the soft rock roadway  
Figure 14: (**a**) Approach of roadway roof and floor; (**b**) deformation of roadway floor (**c**) approach of two sides of roadway.  
were studied, and an effective control plan for the surrounding rock of the roadway was proposed. The main conclusions are as follows:  
1. Field investigations and roof borehole television results showed that the roof and floor of the north return air track roadway are mainly composed of two types of mudstones, yellow mudstone and sandy mudstone. The rock layer on the surface of the roadway was loose and broken, and the deeper part of the mudstone strata had experienced cementation. The average compressive strength of the mudstone was 15.49 MPa, the average tensile strength was 0.72 MPa and the average shear strength was 3.13 MPa, which is typical of a shallow-buried soft rock roadway.
2. Numerical calculations showed that the vertical stress concentrated at both sides of the tunnel, with a stress concentration factor of 1.8 and a depth of 13.9 m. A horizontal stress concentration zone with a factor of 1.2 was formed at 7.0 m at the top and 4.2 m at the bottom, with shear damage dominating the surrounding rock and tension damage occurring at the bottom of the tunnel. After excavation, the deformation rate of the floor was maximum, followed by that of the top slab deformation. The lack of bearing capacity of the U-shape steel caused significant deformation of the surrounding rock, and the lack of filling behind the shed caused the U-shape steel shed roof to break down. Failure of the support system caused further deformation of the surrounding rock, especially the floor drum deformation of the roadway.
3. The trackway was deformed and damaged due to the low strength of the surrounding rock, insufficient strength of the U-shaped steel shed support, and lack of correlation between the U-shaped steel shed and the inability to form a complete unit. The choice of the filling body behind the shed was unreasonable. Therefore, the surrounding rock was controlled by improving the support strength of the roadway, filling the U-shaped steel shed with slurry, increasing the association between the U-shaped steel shed, and preventing the surrounding rock from weathering by spraying slurry on the surface of the roadway. The specific plan was to use the outward sloping form of a straight wall arch retractable bracket of the U29 column leg, with a double-slotted clamp plate upper and lower limit cable. The walls were filled with grout and reinforced with a high-strength steel mesh. A U29 steel counter-arch beam was used to reinforce the floor to control its deformation. Field monitoring showed that this solution could effectively control the deformation of the surrounding rock.  
Conceptualization, Q.Y. and Q.Q.; methodology, L.Z.; software, L.Y.; formal analysis, Q.X.; investigation, L.Z.; data curation, L.Z. and Q.X.; writing--original draft preparation, Q.Q.; writing--review and editing, L.Z. and Q.Y.; funding acquisition, Q.Y. All authors have read and agreed to the published version of the manuscript.  
The authors declare no conflict of interest.