Mechanical behavior and failure modes of jointed rock mass based on rough discrete fracture network models

Rough discrete fracture network (RDFN) models which consider the joint geometry of rock masses were proposed. The uniaxial compressive strength (UCS) of RDFN models with different joint geometries was discussed considering varying scale sizes. The influence of joint geometry on the mechanical behavior, such as compressive strength, shear strength and failure modes, was analyzed. The results showed that the joint geometry have little influence on the linear elasticity of jointed rocks under the uniaxial compressive test. The failure modes were influenced by the joint distribution as well as the joint rough geometry. The UCS was affected by the geometry of the joint network. The UCSs of stepped and fractal RDFN models were relatively higher due to the intersection of rock teeth. The size effect of UCSs with different geometric shapes was significantly affected by joint geometry. The peak shear stress of the stepped RDFN model reached the maximum value and the curved RDFN model was the minimum when the normal stress was lower. The joint inclination and distribution could dominate the shear failure patterns of the jointed rock models, indicating that the influence of geometric shape of the joint must be considered when studying the mechanical properties of synthetic jointed rock mass.

Automated summary

This study investigates the rough discrete fracture network (RDFN) models considering the joint geometry of rock masses. The influence of joint geometry on mechanical behavior is analyzed, showing that it has little influence on the linear elasticity but has significant impact on failure modes and compressive strength. Furthermore, it is found that the geometry of the joint network affects the size effect of UCSs significantly.