Abstract
With the increase of mining depth and strength, the evolution of bolt axial force is increasingly becoming important for ensuring the reliability and safety of support. To improve the problem of the existing coal mine roadway pressure-monitoring method, whereby it is difficult to continuously monitor the axial force of the bolt over a long period of time, a full rod fiber bragg grating (FBG) force-measuring bolt and system were designed based on the principle of fiber grating sensing. It was found that a trapezoidal groove is a relatively better groove. The linearity between the center wavelength offset of the fiber grating and the axial force was more than 0.99, and the conversion formula between the axial force of the bolt rod and the wavelength change of the fiber grating were obtained. The real-time monitoring revealed that the axial force of the bolt obviously changed before and after compression. The axial force distribution curve can be divided into the stable zone, growth zone, and peak zone. The influence of the roadway abutment pressure was approximately 130 m ahead of the working face, and the peak area was within the 25–35 m range of the advance working face. The axial force of the bolt rod at the end of the anchorage linearly increased with the tail end of the bolt, the axial force of the free segment was the largest, and the overall stress was essentially the same. The application results demonstrate the feasibility and effectiveness of the FBG full-length force bolt.
Highlights
The bolt support method is safe and efficient and is the primary support method used in China’s coal mine roadway
The working face was pushed by 180 m in total, and the real-time monitoring data of the bolt
The working face was pushed by 180 m in total, and the real-time monitoring data of the axial force of two measuring stations and three parts were obtained
Summary
The bolt support method is safe and efficient and is the primary support method used in China’s coal mine roadway. This is an active support method, and it provides timely support resistance to the surrounding rock and effectively improves the surrounding rock strength to restrain the separation and deformation of the surrounding rock [1,2,3]. To increase the reliability of bolt support and roadway safety, it is becoming increasingly important to monitor the law governing the bolt’s axial force evolution by means of refinement. The other is to test the pull-out force and axial force of the bolt cable
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
