Study On Failure Mechanism Of Multi-flaw Rock Masses With Experimental Validation And Numerical Simulation

The fracture mechanism of multi-flaw rock mass and crack propagation mechanism are crucial research subjects of geotechnical engineering. Destruction and instability of numerous geotechnical engineering can be mainly attributed to propagation and interaction of crack in rock mass under external force, however, current research has many disadvantages. Hence, study on the failure mechanism of multi-flaw rock mass is constantly a popular topic of rock fracture mechanics. To simplify research difficulty, assumption and replacing3D with2D are normally utilised. Considering that in reality multi-flaw rock mass is in3D state,3D issue of multi-flaw rock mass has not been handled properly. Based on this, research on the fracture and failure mechanism of multi-flaw rock mass is of fundamental importance to theory and reality.Since it is almost impossible to conduct crack propagation experiment with preparing internal crack in rock, the research on failure mechanism of multi-flaw rock mass is a combination of experimental validation and numerical simulation. In terms of experimental validation, according to imitating principal, the sample of multi-flaw rock mass is prepared with similar materials. Meantime, the sample made by similar materials coincides with the property of rock mass. High tension-compression ratio is the distinct character of brittle rock. The sample with built-in multi-flaw agrees with the principal character of brittle materials. The brittle rock-like material is made up of resin, hardener and accelerator. The tension-compression ratio of highly brittle material can reach more than1/5in normal temperature. Compared with previous work, brittleness is greatly improved. To investigate crack propagation process of multi-flaw specimen, desirable transparency is necessary for the prepared material.The whole process of3D crack initiation, propagation and disruption of brittle material is studied under uniaxial and biaxial loading condition. Based on characteristic curve of stress-strain, the failure process can be divided into four sections. The experiment result demonstrates that the phenomenon of3D crack propagation is more intricate than that of2D crack propagation and the phenomenon of crack propagation under biaxial loading condition is more complicated than that of uniaxial loading condition. In terms of numerical simulation, first and foremost, the basic principle, elastic brittle damage evolution and evolution equation of software(FLAC3D) are introduced. Self-development program with FISH language is employed to simulate the whole process of built-in3D multi-flaw specimen. A series of characters under uniaxial and biaxial compression with diverse amounts and stagger of crack are compared. The method of experimental validation and numerical simulation is hired to investigate3D crack propagation process which basically reveals the failure mechanism of multi-flaw rock mass. Furthermore, it deepens understanding of multi-flaw rock mass instability in the domain of rock engineering and affords corresponding technical support for penetrating into forthcoming similar issues.