A range of failure mechanisms from small scale spallation under fire to large scale rockbursts in mining excavations involve extensive crack growth in biaxial compression. The thesis investigates this type of crack growth using biaxial compression testing with different load ratios of frozen resin samples containing 3D internal defects of different types. The triggering nature of the intermediate principal stress was discovered: when its magnitude is above a certain threshold (5-8.5% of the major principal stress) it changes the mechanism of propagation of real three dimensional cracks allowing them to grow extensively to the sizes causing catastrophic rock failure.
|Qualification||Doctor of Philosophy|
|Award date||13 Apr 2020|
|Publication status||Unpublished - 2019|