关键词: 等效岩体技术, 节理, 岩体, 颗粒流, PFC, 力学特性

Abstract: Based on the in-situ observations of a high-steep rock slope in Baiyun Ebo eastern open-pit iron mine, and the data of mechanical properties of rocks and joints, an equivalent rock mass (ERM) model is developed to describe the joint distribution characteristics at multi scales from laboratory tests, in-situ tests to engineering applications. Uniaxial compression tests are conducted on rock mass ERM models to investigate the scale effect and anisotropic properties of uniaxial compressive strength and elastic modulus. The results show that the existence of joints results in the size effect and anisotropic behaviour of rock mass, and these properties tend to gradually weaken with the increase of rock block size. The representative elementary volume, uniaxial compressive strength and elastic modulus of rock mass in the selected research area are 20 m×10 m×10 m, 1.46 MPa and 3.91 GPa, respectively. The relation between uniaxial compressive strength, elastic modulus and the axial size of rock mass is approximately a gradual exponential function which can directly represent mechanical parameters of rock mass.

Key words: equivalent rock mass technique, joint, rock mass, particle flow, PFC, mechanical properties