A Rockburst Hazard Assessment Framework for Strainbursting
摘要
The selection or design of an appropriate support system in burst-prone ground requires a means of assessing rockburst hazard, which is the likelihood that a section of tunnel experiences sudden or violent damage of a certain severity within a given period of time. This article presents an approach to perform such an assessment in the case of a strainburst damage mechanism that can be undertaken by mining staff on a routine basis. The proposed methodology takes into account a number of types of information, including excavation geometry, stress models, rock-mass properties, seismic data, ground support, and underground observations. The stress models used include only large-scale excavations (e.g., caves and stopes) explicitly, with the loading of tunnels determined as a post-processing step. This implicit treatment of tunnels means that models can be built and solved quickly, and it facilitates the probabilistic simulation of tunnel behavior. To improve the accuracy of the modeled stress distribution, a low-complexity method is presented for approximating the interaction between tunnels, which can lead to significant stress concentrations when tunnels are in close proximity near intersections. A mine-scale example of an extraction level at a schematic block-caving mine is used to demonstrate this method and the proposed framework for strainburst hazard assessment.