Research On Uniaxial Compression Failure Process Of Hard Rock With Filled Crack

Due to the constant motion of the earth's crust and development,rock medium shows a significant discontinuity with a large number of joints,fissures and other discontinuities interface.The deformation mechanism and failure modes of rocks under the action forces,to a large extent,are decided by the structure characteristic of discontinuities interface.In order to study the failure process and fracture mechanism of rock with filled crack,this paper is structured in the following ways:(1)The uniaxial compression test is performed on the rock which have preexisted crack with different inclination angle and different fillings.Through the test to analyze the deformation evolution characteristics,the stress-strain curve shape,strength properties,preset cracks form,the crack angle and expansion mode,and study the influences of pre-existing flaw inclination angle and fillings on rock failure process.Based on this,the constitutive model of rock with filled crack is revised.(2)By using numerical tool EPCA2 D,the failure process of hard rocks with pre-existing flaw and fillings under uniaxial compression is conducted.The numerical results on the influences of different pre-existing flaw inclination angle,different fillings and different flaw width are described.The main results are as follows:(1)As the flaw becomes steeper,the crack initiation position will be close to the flaw tip region and the crack angle will be larger;The rock strength will decrease at first and then increase.(2)When the fracture contains filler materials,the strength will increase obviously and the increase range will be larger along with the increase of filling's elasticity modulus.(3)When no filler in the crack,the strength will be decreased with the increase of crack width,but when the fracture contains different filler materials,the strength will appear different change law crack width will present different change law with the increase of fracture width.(4)Whether the fracture has filling or not,the failure modes of the rock are all because of the combination shearing stress and tensile stress,but the damage pattern are different.The shear fracture is more obvious when the fracture contains fillings and the tensile failure is more significant when the fracture is not filled.In conclusion,this paper is an attempt to study the effects of different flaw inclination,different filling materials and different flaw width on the crack propagation behavior by the experimental studies and numerical simulations,and is of certain guiding significance to the actual project.