Study On The Numerical Simulation Of Tension Fracture Process For Rock Bridge

Rock bridge is the main internal structure when it is under external loads , rock bridge and crack assumed loads jointly, rock destruction is usually composed of cracks and rock bridge joint destruction. Due to the existence of rock bridge, let the transfixion crack of rock stress and destruction features happened a qualitative change, crack at the end of the stress will lead to more centralized, so brittle fracture destruction, overall destruction features performance for prefabricated crack and prefabricated crack tip produces wing crack rock bridge rupture consisting of composite destruction. Analysis of crack rock strength properties and its deformation and failure mechanism, is the basic work, rock properties can be reasonably predicted actual failure mode and evaluation of engineering rock stability.The article studies rock bridge Tension rupture, and the evolution process of rock bridge rupture rule. Mainly introduces the crack tip of stress field and displacement field, crack instability extended criterion and the mechanical properties of rock bridge weakening analysis related theory, with rocks tensile damage theory as a foundation, gives four criteria to the rock Tension rupture, a finite element model, the numerical simulation results calculated, simulation analysis of rock bridge tension rupture results. Finite element method is currently used the most extensive research tools, but the traditional finite element method is based on the continuity and the assumption of simulated rock, cannot tension after the bursting of the discontinuous structure formed directly, cannot pull handle rock damage phenomenon problem. Rock bridge tension rupture evolution process is simulated on different rock bridge crack Angle, different number of rock bridge by Using described tension broken finite element method.The simulation results show that the uniaxial compressive conditions, for the same crack Angle, equal distance of two groups of parallel pre crack, in different rock bridge obliquity conditions, advance crack propagation on different degree; The bigger the rock bridge Angle is ,The easier tension destruction occur. Rock bridge obliquity certain Angle, the greater the tensile stress in the region to concentrate on rock bridge, when prefabricated crack is bigger than 75°, tensile stress in rock evenly distributed gradually. The bigger the number of rock bridge is, the easier tension damage occur, meanwhile transfixion trend obviously. The size of the crack affects its propagation degree but have no effect on damage form。Lateral pressure have great affect on the crack's occur, extension and interaction. The process of rock bridge tension rupture finite element program simulation provides a new research method for the study of rock bridge transfixion crack growth rule。...