Back to Search
Start Over
DEM investigation of rock/bolt mechanical behaviour in pull-out tests
- Source :
- Particuology. 52:10-27
- Publication Year :
- 2020
- Publisher :
- Elsevier BV, 2020.
-
Abstract
- Rock bolt anchorage performance is crucial for tunnel support safety. We investigate the mechanical behaviour of reinforced rock and the bolts that reinforce it from the micro-scale to the macro-scale. Bolt pull-out tests were performed on soft rock using the distinct element method, in which a new contact model that considers bond size, is employed to constrain the main rock mechanical behaviour. The minimum sample width and height values for which the boundary effect can be neglected are first proposed through numerous tests on the influence of sample size on peak load and bond breakage. The influence of sample width is substantially greater than that of sample height. We then select an appropriate sample size to study the influence of bolt embedment length and confining pressure on the mechanical behaviours of the rock and bolt. The results show that increased rock bolt embedment length and confining pressure can increase the peak load; however, the bolt length effect is limited when exceeding the critical anchorage length. In cases without confining pressure, bond breakage occurs in the rock around the grout-rock interface and the breakage zone is rectangular, whereas in cases under confining pressure, the breakage zone presents an inverted cone shape. We use our results to discuss the influence of bond strength at the bolt–grout interface on the peak load and failure mode. The failure mode changes gradually from complex failure to single failure along the bolt–grout interface with decreasing interfacial bond strength.
- Subjects :
- Rock bolt
Materials science
Embedment
Bond strength
General Chemical Engineering
02 engineering and technology
021001 nanoscience & nanotechnology
Overburden pressure
Discrete element method
020401 chemical engineering
Breakage
General Materials Science
Geotechnical engineering
0204 chemical engineering
0210 nano-technology
Failure mode and effects analysis
Interfacial bond
Subjects
Details
- ISSN :
- 16742001
- Volume :
- 52
- Database :
- OpenAIRE
- Journal :
- Particuology
- Accession number :
- edsair.doi...........b785a987faec6b09b36aa3d7bd111127