# Safety Status Monitoring of Operational Rock Bolts in Mining Roadways Under Mining-Induced Effects

## TL;DR

This study uses fiber Bragg grating sensors to monitor rock bolt safety in mining roadways, showing how axial forces change with mining activity.

## Contribution

A novel method for real-time monitoring of rock bolt axial forces using embedded FBG sensors in mining environments.

## Key findings

- Axial force in bolts increases as the mining face advances, with sharp rises observed after 60 m.
- Left gang bolts show significant force changes, while right gang bolts show smaller variations.
- Real-time monitoring provides critical data for evaluating bolt stability and safety in mining roadways.

## Abstract

This study focuses on the importance of the real-time monitoring of bolt loads in roadways affected by high-intensity mining and the limitations of conventional monitoring methods. Fiber Bragg grating (FBG) sensors were embedded and encapsulated in rock bolts, and tensile tests were conducted indoors to verify their feasibility. The research was conducted using the consolidated face of the Bultai Coal Mine in the Shendong Mining Area as the engineering background. Real-time monitoring wavelength data from the FBG bolt sensor were obtained through field tests. The analysis of the data aimed to assess the condition of the FBG sensor and variations in axial force within the service bolts of the mining roadway. Using these monitoring results, the real-time stability and safety of the roadway bolts were evaluated. The study indicates that as the working face advances, the axial force in the bolt progressively rises under the effect of mine pressure. The left gang bolt rod’s shaft force changes significantly, while the right gang’s change is relatively small. When the working face moves 60 m past the bolt rod, the axial force in the bolt rises sharply. Moreover, the axial force at different positions of the left and right gang bolts exhibits a distinct variation pattern. The real-time monitoring of bolt support in the return roadway provides essential data for assessing bolt safety.