## 4 The Proposal and Application of Primary Strong Active Support  
### The Proposal of Roadway Support Technology  
According to the mechanism of roadway creep instability and considering the characteristics of weak and fractured roadways, extensive surrounding rock deformation, and failure of the supporting structure, this paper proposes a supporting principle. The principle combines high pre-tightening anchorage to increase the surface and internal confining pressure of the roadway, thereby improving the initial strength of accelerated creep in the coal body. Additionally, high-strength surface protection is utilized to enhance the initial stiffness of the support system, ensuring the integrity of the loose coal body within the roadway. Moreover, high-strength overall support and structural compensation are implemented in key local areas such as shoulder sockets and bottom angles. Based on the above support principles, the primary strong active support technology of \"high pre-tightening force of high-strength bolt and anchor cable, steel mesh + plastic mesh cooperative protection table\" is proposed, and its support effect in creep control of surrounding rock of a soft coal roadway is simulated and verified in order to obtain the optimal support scheme parameters. To investigate the impact of bolt prestressing on the deformation of the surrounding rock, a study was conducted under the specified conditions: bolt length of 2.6 m and spacing of 0.8 m. The prestressing forces considered for the bolts are 20 kN, 40 kN, 60 kN, and 80 kN, respectively. The simulation was focused on the left rib, which experienced more significant damage. The precise location of this simulation is illustrated in Figure 8. The diamond metal mesh with Poisson's ratio 0.3, elastic modulus 188 GPa, \(\Phi\)4 mm, and the steel bar welding mesh with Poisson's ratio 0.25, elastic modulus 210 GPa, and \(\Phi\)4 mm, were selected to analyze the deformation of the left side of the roadway. The deformation of the left side of the roadway is shown in Figure 11.  
Based on the aforementioned support principles, a primary strong active support technology is proposed, which involves the use of high pre-tightening forces applied  
Figure 11: Roadway deformation under different parameters: (**a**) The maximum deformation curve of the left rib of the roadway with the pre-tightening force of the bolt; (**b**) The time-varying curves of left rib deformation of different metal mesh types. to high-strength bolts and anchor cables, along with a cooperative protection surface consisting of steel mesh and plastic mesh. The effectiveness of this support technology in controlling creeps in the surrounding rock of soft coal roadways is simulated and verified to determine the optimal parameters for the support scheme. Different pre-tightening forces were employed to simulate the left side of the roadway, which exhibited more severe damage. The deformation of the left side of the roadway was analyzed using diamond metal mesh with a Poisson's ratio of 0.3, an elastic modulus of 188 GPa, and a diameter of \(\Phi\)4 mm, as well as steel bar welding mesh with a Poisson's ratio of 0.25, an elastic modulus of 210 GPa, and a diameter of \(\Phi\)4 mm. The deformation of the left side of the roadway is illustrated in Figure 11.  
From Figure 11a, it is evident that the greater the pre-tightening force applied to the selected bolt, the more significant the reduction in deformation of the left side of the roadway. This indicates that increasing the confining pressure of the roadway can effectively mitigate the instability of creep deformation in the soft coal roadway. The creep characteristics of the roadway under different anchor mesh supports exhibit distinct patterns, as shown in Figure 11b. The deformation curves of the surrounding rock under the support of steel welded mesh and diamond metal mesh reflect the steady-state and unsteady-state creep characteristics of the left coal body, respectively.