307 / 2018-05-03 12:50:41

Analysis of the Deformation and Fracture of Underground Mine Roadway by Joint Rock Mass Numerical Model

Particle Flow Code, Nishihara Model, Jointed Rock Mass Numerical Model, Rheological Properties, Roadway Deformation and Fracture

矿山安全科学理论与应急救援 > 矿山安全管理

Joints in rock mass and rheological properties are the main causative factors in many engineering disasters. It is therefore important to study the rheological properties of jointed rock mass. A user-defined visco-elastoplastic Nishihara contact constitutive model is developed based on Particle Flow Code in three dimensions (PFC3D). And the model is verified by numerical experiments. Using the model to build a jointed rock mass numerical model to analyze rheological properties and failure behavior of a tunnel surrounded by jointed rock mass of the Zhangjiawa iron mine in Shandong Province of China. Firstly,The rock specimens from a roadway tunnel in the Zhangjiawa mine are used to acquire the calculation parameters through uniaxial and triaxial compression and uniaxial compression creep experiments. The joint distribution law is then determined from a statistical analysis of joints on the tunnel walls. Based on the tunnel joint network constructed using the Monte-Carlo method, a jointed rock mass numerical model is established. Finally, the rheological properties of the jointed rock mass are separately analyzed using the Nishihara model and the linear elastic model. According to the results from the linear elastic model the deformations of the tunnel roof and sides do not change with time and the model does not exhibit rheological properties. In contrast, the results of the user-defined Nishihara model show obvious creep properties. The bonds of the joint face in the jointed rock mass model are primarily destroyed by shear failure. The failure modes and deformation data for the tunnel are generally consistent with field monitoring data.