Numerical simulation technique for gateroad stability analysis under fractured ground condition
Abstract
The ground stability of gateroads is a major concern in underground coal mines, especially where the surrounding strata are weak and fractured. This paper presents a novel numerical modelling technique for gateroad stability analysis based on a case study conducted in Zhaogu No.2 mine, China. Considering the occurrence of fractures and its weakening effect on the stiffness of rock mass, a tension-weakening model is implemented into FLAC3D, whereby the stiffness of rock mass is progressively decreased according to failure state. A relationship between the intensity of fractures and the residual properties is built. A parametric study of the tension-weakening model with respect to weakening parameter is carried out, and the results are compared to perfect elasto-plastic model and strain-softening model. The comparison shows that the tension-weakening model exhibits a noticeable effect on ground deformation and rock support loading, and can simulate more realistic behavior of a gateroad, which agrees well with field measurements. The proposed model provides a rigorous approach for gateroad stability analysis and can be utilized for rock reinforcement design under similar geotechnical circumstances.References
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