## 6 Discussion  
This study thoroughly conducted the field observation and measurement of the roadway under difficult production conditions and proposed the supporting technology for the core of the HSCTS. For the surrounding rock stability of the underground coal roadway, the proper layout of the coal roadway is also significantly important, so lots of literature pays more attention to the correlation between the roadway layout and ground stress distribution characteristics, especially when combined with the mining-induced horizontal and vertical stress distribution after the working face advanced [9; 13; 19; 20]. The narrow pillar or much wider, narrower pillar could avoid the high mining-induced stress, so it is beneficial to the stability of the roadway. However, with the special production and geological conditions, the layout of the roadway is under the high-stress zone of the goal of panels #10209 and #1411, which leads to the LIMIS. In the limited space of this paper, we will continue to thoroughly study the mining-induced stress distribution characteristics as working faces 10209 and 1411 advance and the proper roadway layout in combination with the advanced numerical simulation and large physical modeling experiment.  
The safeguard to the stability of the roadway layout in the high-stress distribution zone is commonly a tough problem [10; 12]. If there is no proper supporting technology, a large deformation will accompany the roadway excavation. Related literature mainly focuses on the mining-induced stress influence on the surrounding rock stability caused by the nearby working face advancing [18; 25]. However, this production situation with nearby two working faces advancing in this study is much more complex than one working face advancing, as has been significantly testified by multiple supporting scheme adjustments with the roadway excavation.  
For the excavated roadway with very difficult production conditions, the traditional simple growth of the bolts or cable number proved not to be an effective method. Further, a useful supporting structure is much more important than the supporting number. In addition, the integrity of the roof strata could be affected by the decrease in bolt or cable spacing. As a result of this difficult condition, the HSCTS was used to control the bedding separation in the roof strata and surrounding rock displacements. Actually, this supporting system was developed from the initial bolt truss support and then conventional cable truss support [10; 12; 22; 26]. In combination with the higher anchoring force afforded by the capsule resin, the higher strength property of the larger diameter cable, and a more reliable lockset to the roof than conventional roof cable trusses, the supporting structure could afford strong shear and tensile resistance to the high mining-induced stress. Most importantly, this structure helps coordinate the deformation among the roof, coal sides, and floor, resulting in a large reduction of the surrounding rock deformation. Furthermore, the large difference in loading force between the bolt and cable is greatly decreased, and a good, combined effect is also achieved. In all, the surrounding rock stability of the difficult excavated coal roadway in this study has been successfully safeguarded, and there are no repairing activities after the roadway excavation as a limited deformation occurs along with the working face 1409.