Modeling and Simulation of Joint Zone for Stability Analysis of Underground Excavation Engineering

A methodology to model and simulate joint zone for stability analysis of the underground excavation engineering is proposed. Firstly, the jointed rockmass is regarded as a layered anisotropic rockmass zone and a mechanical model of the layered anisotropic rockmass is put forward based on the finite element method (FEM). Secondly, a set of indexes are introduced as the stability assessment indicators to analyze the stability of the surrounding rock using FEM calculation results. Finally, a case study is further illustrated with excavation of an underground pumping house using the proposed methodology to analyze the effect of the steep joints on the surrounding rock stability. Compared to the isotropic condition, when considering the layered anisotropic property with different horizontal and normal elastic modulus, surrounding rock experiences more stress disturbance that resulting in increased plastic zones, dissipation energy and deformation around opening, which is unfavorable for the stability of surrounding rock of the underground caverns. The mechanical model of layered anisotropic rockmass is proved rational and suitable to simulate the joint zone for practical engineering application and of reference.