# The Failure Law and Combined Support Technology of
## 6 Conclusions  
1. The significant buried depth of the roadway, high ground stress, and complex geological structure significantly reduce the overall strength of surrounding rock, resulting in prominent rheological characteristics and large deformation of surrounding rock. The original supporting mode is too single; forming a high-strength and high-stiffness anchorage system between the supporting body and the surrounding rock is difficult. Meanwhile, neglecting to strengthen the weak parts of the floor also leads to the failure of the surrounding rock to form a complete bearing structure, resulting in severe damage and instability. 2. After roadway excavation, the surrounding rock forms the bearing structure of the fractured zone, plastic softening zone, and elastic zone successively from the surface to the inside. The mechanism of significant deformation failure in high-stress soft-rock roadways is that the range of fracture zone and plastic softening zone keeps increasing. It is beneficial to restrain the transfer of surrounding rock stress to the deep and improve the bearing capacity of surrounding rock by increasing the residual value of surrounding rock geological strength index, reducing the disturbance degree of surrounding rock, and ensuring adequate support resistance. 3. Based on the geological conditions of the track roadway, the thickness of the fractured zone and the plastic softening zone in the surrounding rock are determined to be 2.54 m and 5.23 m, respectively. On this basis, the multi-stage strengthening combined support technology of \"high-strength prestressed anchor bolt (cable) support as the core, deep and shallow hole grouting as the foundation, bottom angle and floor anchorage grouting reinforcement as the key\" is put forward. The mechanical mechanism of this support technology is to couple with the mechanical properties of the surrounding rock so that the anchorage system can form a complete and continuous bearing arch structure to ensure the long-term stability of the main bearing body of the surrounding rock. 4. The numerical simulation results show that it is one of the most effective means to control surrounding rock by decreasing the bolt and cable row distance to increase the anchoring area. Compared with the original, the combined support scheme can reduce the tensile stress zone of the roadway surrounding rock and effectively prevent the deformation and failure of the surrounding rock mass. The integrity of the surrounding rock is better when the combined support scheme is adopted, and the roadway deformation is only 12.6-14.3% of that under the original support scheme. In particular, the supporting structure is fully coupled with surrounding rock, and the roadway becomes stable after only 40 days. This effectively solves the control problem of weak surrounding rock in deep wells. Figure 16: Monitoring curve of surrounding rock deformation of track roadway: (**a**) 1# monitoring curve of surrounding rock deformation of track roadway; (**b**) 2# monitoring section. **Author Contributions:** Conceptualization, X.W. and J.T. ; methodology, Y.L. ; software, Q.F. ; validation, X.W. ; formal analysis, J.T. ; investigation, Y.L. ; resources, J.T. ; data curation, Q.F. ; writing--original draft preparation, X.W. ; writing--review and editing, Q.F. ; visualization, J.T. ; supervision, Y.L. ; project administration, X.W. ; funding acquisition, J.T. All authors have read and agreed to the published version of the manuscript. **Funding:** This research was supported by the Natural Science Foundation of China (No. 52174102), Key Research and Development Program of Anhui Province (No. 2022m07020007), Natural Science Research Project of Anhui Educational Committee (No. 2022 AH050811); University-level Key Projects of Anhui University of Science and Technology (13220485); Scientific Research Foundation for High-level Talents of Anhui University of Science and Technology (2021 yirc30); The Anhui Engineering Research Center of Exploitation and Utilization of Closed/Abandoned Mine Resources (No.