Mechanics Experimental Research And Application Of Rock Fracture Under Water-Rock Interaction

For a long time, people always suppose that rock mass are a kind of continuous, homogeneous and isotropic medium, in fact, rock mass almost have cracks in their forming process under long-term geologic structure forces. And these original cracks would develop or produce new secondary cracks for some artificial disturbance in the engineering construction, in order to solve these actual rock engineering mechanics problems, we need to do research from the view of fracture mechanics. At the same time, the water-rock interaction is widely found in nature, and the water is the most active and major factor which induces various geological hazards. When reservoir starts to impound water, the change of reservoir level directly leads to the change of rock mass parameters, which causes the rock properties degradation, and makes the stable slope to develop to the unstable direction. Therefore, the tests of rock fracture mechanics under the action of water-rock interaction have some reference and application to analysis of stability of abutment slope and foundation under the condition of high water level.Through choosing the sandstone rock of a slide of three gorges reservoir area for a representative, the3-point bending fracture test, triaxial compression test and splitting tensile test in the two kinds of different water-rock action processes were carried out; the change rules of sandstone sample’s type Ⅰ fracture toughness KIc, speed of longitudinal wave, compressive strength and tensile strength were analyzed; the correlation between fracture toughness KIc and vertical wave, compressive strength, tensile strength were researched and the empirical formulas were given. At the same time, through statistical methods, continuous damage theory and Lemaitre strain equivalence hypothesis, damages constitutive model of rock in saturated-dry cycle was established based on Mohr-Coulomb strength criterion and the hooker law. Finally, according to the test results, the deteriorating rules of mechanical parameters of rock mass in the saturated-dry cycle condition were researched and the long-term stability of a landslide in reservoir area was analyzed by numerical simulation.