Abstract
Rockburst is a geological disaster in highly stressed ground. As a typical rockburst, strainburst is an ejection failure phenomenon caused by tangential stress concentration, which is frequently encountered in hard-brittle intact rocks in deep tunnel excavation. To explore the strainburst characteristics, a set of tests on rectangular prismatic granite specimens with different loading rates were conducted using an improved true-triaxial testing machine. During the testing process, a special loading path, namely, keeping one free face and loading on other faces, was adopted to simulate the stress concentration of surrounding rock masses near the opening. High-speed cameras were used to record the failure process on the free face of tested specimens. The speed and the kinetic energy of ejected fragments during strainburst were obtained by analyzing videos recorded using high-speed cameras. The experimental results reveal that the loading rate (simulating the rate of tangential stress concentration) plays an important role with respect to the strainburst characteristics. As the loading rate increases from 0.05 to 5.0 MPa/s, the failure mode of tested specimens transfers from static failure (spalling) to dynamic failure (strainburst), and the kinetic energy of ejected fragments during strainburst, as well as the rock strength, increases.
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 callMore From: Bulletin of Engineering Geology and the Environment
Disclaimer: 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.
