Study On Failure Behavior Of Rock Containing Three-dimensional Pre-existing Flaws

Rock Mass,as inhomogeneous medium, often contain a large number of defects,such as3D flaws and pores. Under external loads, the initiation, propagation,coalescence and interaction of these defects, may lead to degradation of the stiffnessand reduction of the strength, even result in potential engineering disasters, such asrock burst, collapse in rock engineering, and deep fracture in the foundationengineering. Therefore, it has been a subject of intensive research on the initiation,propagation, coalescence and interaction of cracks. it is of important scientific andengineering significance to study on failure behavior of rock containingthree-dimensional pre-existing crack.In this thesis, by employing numerical simulation code RFPA3D, the failurebehavior of marble specimens containing pre-existing3D flaws with different anglesand distributions under true triaxial loading were carried out. The main contentsinclude:(1)Make a review of the latest advances in research on the initiation, propagation,coalescence and interaction mechanism of3D cracks.(2)By employing physical testing, material mechanics parameters of the marblespecimen were obtained under true triaxial loading condition.(3)Investigate on the crack initiation, propagation mechanism of specimenscontained the3D pre-existing flaws under different lateral pressure condition.(4)Study on the failure behavior of specimens containing a single3D flaw withdifferent pre-existing angles including: the relationship between the pre-existingangle and the peak strength, the failure pattern and crack propagation mechanismwith different angles.(5)Study on the the coalescence mechanism of specimens contained multiple3Dflaws. The coalescence pattern and the relationship between peak strength withdifferent rock bridge angles were summarized.