The study examines empirical and numerical modeling methods that can be used to predict the depth of notch failure in bored raises excavated for Glencore’s Onaping Depth project within the Craig Mine complex in Sudbu...The study examines empirical and numerical modeling methods that can be used to predict the depth of notch failure in bored raises excavated for Glencore’s Onaping Depth project within the Craig Mine complex in Sudbury,Ontario,Canada,at depths between 1150 and 1915 m.These raises experienced significant notch growth throughout their entire length.A detailed assessment found four mechanisms of deterioration causing the notch growth.Of these mechanisms,stress fracturing and scouring contributed to most of the notch growth.These two mechanisms,when working together,magnify their individual effects,making their combined contributions difficult to predict using existing empirical approaches and numerical models.Hence,a new and innovative approach is presented to simulate the progressive notch failure observed in the Onaping Depth raises using FLAC3D.Due to the inability of FLAC3D to simulate rock fracturing directly,an iterative process is established where elements that meet a damage criterion considering cohesion and volumetric strain are removed from the model,and the model equilibrium is restabilized with additional damage forming.The final stabilized notches simulated with FLAC3D show a good agreement with the geometry observed in the raises.This representation of notch failure is more realistic,which is different from the conventional approach of using yielded elements to represent failure zones in continuum models.This work provides insight into deterioration in bored raises and establishes a framework for predicting deterioration and its growth,thereby enhancing the understanding of rock mass response to mining activities.展开更多
文摘The study examines empirical and numerical modeling methods that can be used to predict the depth of notch failure in bored raises excavated for Glencore’s Onaping Depth project within the Craig Mine complex in Sudbury,Ontario,Canada,at depths between 1150 and 1915 m.These raises experienced significant notch growth throughout their entire length.A detailed assessment found four mechanisms of deterioration causing the notch growth.Of these mechanisms,stress fracturing and scouring contributed to most of the notch growth.These two mechanisms,when working together,magnify their individual effects,making their combined contributions difficult to predict using existing empirical approaches and numerical models.Hence,a new and innovative approach is presented to simulate the progressive notch failure observed in the Onaping Depth raises using FLAC3D.Due to the inability of FLAC3D to simulate rock fracturing directly,an iterative process is established where elements that meet a damage criterion considering cohesion and volumetric strain are removed from the model,and the model equilibrium is restabilized with additional damage forming.The final stabilized notches simulated with FLAC3D show a good agreement with the geometry observed in the raises.This representation of notch failure is more realistic,which is different from the conventional approach of using yielded elements to represent failure zones in continuum models.This work provides insight into deterioration in bored raises and establishes a framework for predicting deterioration and its growth,thereby enhancing the understanding of rock mass response to mining activities.
