Numerical Simulation of Influence of Prestress on Rock Crack Propagation

Based on the damage evolution law of energy, through the three-point bending test of granite, the calculation formula of three-point bending fracture energy of rock dominated by type I fracture failure is calculated, and the influence of dimensionless prefabricated crack length and prestress on rock fracture failure caused by crack propagation is studied. The results show that with the increase of dimensionless prefabricated crack length, the peak load of granite increases, but its fracture toughness increases first and then decreases. The size and application of prestress have different effects on crack propagation in rock samples. It is proposed that the influence factor of prestress is used to characterize the strength of crack propagation inhibition. In engineering construction, high strength prestressed anchor bolts and expanded support area can be adopted to prevent collapse accidents caused by excessive deformation of surrounding rock.