## 5 Conclusions  
In the process of tunnel construction, problems such as high-stress rockbursts, soft rock deformation, water inrush, secondary lining cracking, blasting interference, man-made damage, and mechanical damage are often encountered. These all pose great challenges to the installation of monitoring equipment and line protection. However, the short aperture of fiber material itself, the brittleness of its texture, and the difficulty of disconnection limit the wide application of fiber grating technology. In view of these problems, the 2# inclined shaft of Muzhailing Tunnel in Gansu Province of China, with high stress, water bearing, and bias properties, was taken as the research object in this paper. The results of the study were as follows:  
1. This paper adopted FBG technology to realize the first application of a high ground stress tunnel in deep and long-distance water-rich weak surrounding rock. It overcame the problems of the short aperture of the fiber itself, the brittleness of its texture, and the difficulty of disconnection. 2. New methods for optical fiber multi-point displacement sensor installation and steel arch meter installation were proposed, which could realize surrounding rock deformation monitoring and continuous strain monitoring. The methods were proven reliable. Associated stability problems provided new ideas for ongoing research into complex soft rock large deformation tunnels under high stress, water bearing, and bias conditions. 3. Through the analysis of the convergence curve characteristics of deep surrounding rock and the stress characteristics of the steel arch, the beneficial effect of NPR bolt harness coupling support technology in a soft rock tunnel was verified. 4. Through analysis of the displacement rate velocity of the measuring point, it was judged whether the measuring point was in the loose circle, and the range of the loose circle was further inferred. It was verified that the surrounding rock loose circle was basically stable at a depth of about 1 m after the application of the NPR anchor cable coupling support. Through analysis of the relationship between the displacement fluctuation caused by blasting and the working face, it was concluded that the main influence range of blasting was at a depth of 0-5 m in the surrounding rock, 25 m away from the working face. 5. In view of the weak link in the steel arch frame, a locking foot catheter (\(\Phi\)42, L = 4.5 m, quantity 2, placement angle 45\({}^{\circ}\)-50\({}^{\circ}\)) was set at the arch frame, and this combined bearing of the steel arch frame was the most effective. By further analyzing the stress variation characteristics of the steel arch, it was deduced that the fatigue life of the steel caused by the fatigue cracking factor should be fully considered in the fatigue design of the support. In this case, it was suggested that the fatigue life of the steel should be used to inform the selection index of the steel arch in support design to ensure the stability of surrounding rock and the long-term safety of the tunnel. Conceptualization, C.R. ; methodology, C.R. ; Investigation, C.R. ; resources, M.H. ; data curation, C.R. ; writing--review and editing, C.R. ; project administration, X.S. and Z.T. ; funding acquisition, X.S. and Z.T. All authors have read and agreed to the published version of the manuscript. This project was supported by the National Key R&D Program of China (Grant No. : 2016 YFC0600901), the National Natural Science Foundation of China (Grant No. : 51874311), the Yueqi Outstanding Scholars Award of China University of Mining and Technology (Beijing), the Key R&D Program of Zhejiang Province (No. 2019C03104) and the Basic Research Funds of Central Universities(Grant No. : 2015 QB02). We sincerely thank the anonymous reviewers for their constructive comments and the editors for their careful and patient work. **Institutional Review Board Statement:** Not applicable. **Informed Consent Statement:** Not applicable.