Research on the influence of consolidation time of filling slurry on crack propagation of granite based on DIC

Abstract：In order to study the effects of deformation and failure of fissured rock mass in underground engineering on the stability control of rock mass, the strain field evolution process of unfilled fissured rock and filled fissured rock under uniaxial compression was monitored.Based on the digital image correlation method (DIC) , Combined with the sliding crack model theory, the pattern of crack initiation, expansion, and penetration in the process of fissured rock failure was analyzed systematically from the macro and micro view.The results showed that, the maximum strain in the unfilled fissured rock field was mainly concentrated on the junction of two pre-existing fissures tip and through failure along one side of pre-existing fissures.However, the maximum strain value of the filled fissured rock field was mainly concentrated at the joint of two pre-existing fissures and anti-wing crack propagation, and the failure was through along the two sides of the pre-existing fissures.The rock bridge boundary area of unfilled fissured rockwas dominated by shear failure mainly, while the rock bridge area of filled fissured rock was dominated by tensile failure.Whether the fracture had filled or not, the strain field was mainly divided into tensile stress zone and compressive stress zone.In the elastic stage, a local failure strain band had been formed along wing crack and anti-wing crack propagation path in the strain field.The overlap of inner wing crack and anti-wing crack was the most serious.With the extension of the consolidation time of the filling, second coplanar crack by shear stress at the tip of pre-existing fissures was expanded, and the roughness of the section was higher than other sections.

Keyword：fissured rock;digital image correlation method;consolidation time;crack propagation;failure law;