A New Criterion for Numerical Modelling of Hangingwall Overbreak in Open Stopes

Vallejos, Javier; Díaz, Leonor

doi:10.1007/s00603-020-02179-z

Cited by 16 publications

(5 citation statements)

References 22 publications

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“…The constitutive modelling is at this stage based on the linear elastic model. Such a linear elastic model has been utilised in simulations regarding dilution prediction in stoping operations; compare Vallejos & Díaz (2020). These dilution mechanisms in stoping and caving have in common that rock mass detaches from stope walls.…”

Section: Unsophisticated Simulation Methodsmentioning

confidence: 99%

Development of an unsophisticated numerical simulation model for caving systems

Lozano¹,

Nöger²,

Ladinig³

et al. 2022

Caving 2022: Fifth International Conference on Block and Sublevel Caving

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The main objective of this publication is the description of an unsophisticated methodology to predict caving and cave propagation for mining purposes based on numerical simulations. The aim of the methodology is to create a user-friendly tool which requires little effort to set up and analyse and which facilitates understanding of cave propagation for practical applications.The methodology is defined as an algorithm which is performed in FLAC3D, version 7.0 (Itasca 2019). The constitutive modelling is based on model elastic behaviour, due to its simplicity and low running times. The algorithm utilises a series of routines that describe and quantify the failure process of rock during caving.The emphasis of the methodology is on simplicity, which is reached by implementing reasonable assumptions regarding the caving situation and the rock mass behaviour. The caving propagation is driven by plastic behaviour; however, to simplify the model the caving algorithm is based on an elastic behaviour and specific functions mimicking the plastic behaviour, namely the degradation processes occurring in the rock mass during caving are accounted for by reducing the mechanical properties of the rock mass and the stress state in degraded zones in a controlled and systematic manner. Sensitivity tests are performed to analyse the weight of the mechanical parameters involved in the caving processes, as well as to optimise the reduction rate of the mechanical properties of the rock mass.The calibration of the caving algorithm is the current stage of the development. The calibration is carried out by analysing the results obtained in the numerical models and the outcome of the semi-empirical methods available in the literature.The unsophisticated caving predicting tool is being developed for its application on the novel raise caving mining method (Ladinig et al. 2022). The caving tool will supply understanding regarding the caving initiation and propagation for the novel raise caving method.

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Section: Unsophisticated Simulation Methodsmentioning

confidence: 99%

Development of an unsophisticated numerical simulation model for caving systems

Lozano¹,

Nöger²,

Ladinig³

et al. 2022

Caving 2022: Fifth International Conference on Block and Sublevel Caving

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“…To avoid the disadvantages of empirical stability graph methods, many numerical modelling studies have been carried out to estimate ore dilution and HW overbreak using site-specific geometric and geotechnical data of mines. However, most early modelling studies, as well as current work, only focus on the stope overbreak assessment of an isolated type stope with no previous mined-out areas (Urli & Esmaieli, 2016;Heidarzadeh et al,2019;Vallejos & Díaz, 2020;Hefni et al, 2020). Alternatively, the stope overbreak is not actually modelled during stoping simulation, e.g., overbreak areas attach to stope wall rather than being mucked out in the modeling (El Mouhabbis et al, 2009).…”

Section: Proposed Numerical Modelling Methodologymentioning

confidence: 99%

Strategies for surface crown pillar design using numerical modelling – A case study

Chen

Mitri

2021

International Journal of Rock Mechanics and Mining Sciences

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“…To predict the depth of the hanging wall rocks destruction, the authors use the Evolutionary random forest (ERF) method, where the algorithm has revealed high convergence with the actual data of the mine [51]. A new criterion for assessing the stability of the hanging wall rocks has been developed, which testifies to a significant influence and interdependence between the rocks quality and the principle of the load formation on the overlap of the hanging wall rocks [52]. A number of other studies are also known to be related to the stability of hanging wall and foot wall rocks that come into contact with extraction stope in the process of ore mining [53][54][55][56].…”

Section: Introductionmentioning

confidence: 99%

Instability Assessment of Hanging Wall Rocks during Underground Mining of Iron Ores

et al. 2021

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The paper presents the study of the deformation processes development in unstable rocks of the hanging wall during mining a thick steeply dipping ore deposit in the example of the Yuzhno-Belozerskyi deposit. In the studied field, there are problems of stability of hanging wall rocks, represented by low-resistant shale rocks that do not withstand significant outcrops in time. A decrease in stability is manifested in the form of failure of the hanging wall rocks into the stope. Based on a detailed study of the ore deposit geological structure and the performance of the stopes mining, according to the survey data, an area of the deposit has been identified where the ore failure and dilution reach 4%–8% with a maximum value of 12%. This also makes it possible to determine the most important averaged source data for performing physical modeling on equivalent materials. It has been determined that the deformation value of the hanging wall rocks with subsequent failure into the stope and ore mass deformation in the sloping bottom change exponentially with an increase in the depth of the stope location, and the dynamics of increasing rock deformations in the hanging wall is noticeably higher than in the sloping bottom of the stope. This reduces the quality of the mined ore and increases the probability of rock failure area propagation to the hanging wall drifts with their subsequent destruction. The results of physical modeling are characterised by acceptable reliability and are confirmed by a high similarity with the actual data on ore dilution with broken rocks during the stopes development. It has been found that during the formation of a steeply dipping outcrop of stopes with an area of 1200 m2, unstable rocks of the hanging wall are prone to failure of significant volumes. For successful mining and achieving stope element stability, it is recommended to optimise its parameters, the height, width and the value of a steeply dipping outcrop, as well as to preserve the ore pillar in the hanging wall until the ore is broken and drawn from the rest of the stope.

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A New Criterion for Numerical Modelling of Hangingwall Overbreak in Open Stopes

Cited by 16 publications

References 22 publications

Development of an unsophisticated numerical simulation model for caving systems

Development of an unsophisticated numerical simulation model for caving systems

Strategies for surface crown pillar design using numerical modelling – A case study

Instability Assessment of Hanging Wall Rocks during Underground Mining of Iron Ores

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