Full article: Stability analysis of crown pillar under the zone …
To design an optimal crown pillar, a comprehensive investigation is necessary for each mine, focusing on the behaviour of the crown pillar regarding stress distribution, roof convergence, and yielding zones under the relaxation zone (Hosseini et al. Citation 2023). Geological and geo-mining conditions vary greatly between mines due to the ...
Use of an artificial crown pillar in transition from open pit …
In the transition from open pit to underground mining, a crown pillar is usually left at the open pit bottom. Crown pillars are often not recovered and as a result they are deemed as permanent losses.
Use of an artificial crown pillar in transition from open pit to
Based on theoretical calculations, empirical analysis and numerical modelling, this study analyzed the process of mining a natural ore rock crown pillar and simultaneously …
CPillar Tutorials | 4
Our Crown Pillar Scaled Span (Cs) value has been calculated and an area has been highlighted on the chart. It is calculated using the equation shown in the dialog. ... This would be acceptable in a mining block where surface risks can be mitigated perhaps by incorporating "continuous sophisticated monitoring" if critical surface ...
Strategies for surface crown pillar design using …
crown pillar - the rock cover consisting of ore rocks that are left above the uppermost stopes - is to separate the overlying surface from the underground mining operation. Although the problem of surface crown pillar design has been researched for more than 30 years, the underlining stability mechanisms and design guidelines are still limited.
Application of empirical methods to estimate crown …
The use of this equation provides the optimal crown pillar thickness to operate a mine under combined open pit and underground operations. Case studies Caving 2022, Adelaide, Australia 853. 4 Seismogenic observations of crown pillar failure Actual CPF can be monitored in several ways. In this work, seismic monitoring will be used as the main tool
Crown Pillar Optimization for Surface to Underground Mine …
A crown pillar is to be designed in the transition region from surface to underground operations. Crown pillar dimensioning effects the overall ore recovery in such small-scale ore bodies. Proper dimensioning has to ensure the stability of open pit mine slopes and underground mine structural units as underground mining progresses to upper levels.
Review of crown pillar investigations in a historic mine …
mine openings and crown pillar, low confining stress, rockmass quality, mining method, and presence of adjacent mining voids (Hutchinson et al, 2002). Other factors that increase the probability ...
The Reissner–Ritz Method for Solving the Deflection
The crown pillar of the method of mining in an empty space meets the definition of a thick plate, and all four sides are fixed support before its failure. For the purpose of analysis, the geometric region of the stope is considered as a rectangular region, and the crown pillar is regarded as an elastic rectangular thick plate under the boundary ...
Crown-pillar risk assessment-planning aid for cost-effective mine …
Assessing crown stability Since in almost all situations where a crown pillar has been used in mining there are significant differences between the overall rock mass characteristics of the ore zone and those of the hanging-wall and footwall, it is clear that attempts to describe the stability of such crowns by means of a singlevalue factor of ...
A Review of Models and Algorithms for Surface-Underground Mining …
The positioning of the required crown pillar thickness in the SUMOTO problem is key to the operations of such mines. Some authors pre-selected the depth of the crown pillar (transition depth) before evaluating portions above the crown pillar for open pit mining and portions below the crown pillar for underground mining [4,18,25,27,28]. This may ...
Risk considerations for crown pillar stability assessment for mine …
Evaluation of the long-term surface stability of crown pillars overlying underground mines is an important component of mine closure planning. The definition of a crown pillar, as well as a brief discussion of the assessment of the probability and consequence of crown pillar failure are given in this paper. Techniques for stability assessment using mechanistic, empirical and numerical ...
Underground metal mine crown pillar stability …
The open stope mining method is the most common underground extractive technique used in Australian metalliferous mines. The crown pillar as it stands in the vertical plane between two open stopes is an integral part of the global …
Numerical simulation study on stability analysis of …
the crown pillar for a gold mine orebody existing below a tailing dam are studied in detail by Chen and Mitri (2021). Numerical modelling is mostly carried out using the softwares like Fast Lagrangian Analysis of Continua in 3D (FLAC3D) (Li et al. 2013), CPillar, where the rock strata
Risk Evaluation, Design, Implementation, Instrumentation, and
The Santo Niño ore body at Pinos Altos Mine has been in production since 2009 using both open pit and underground mining methods. Between 2015 and 2017, an extensive study evaluated extraction strategy of the Santo Niño crown pillar. The Agnico Eagle project team evaluated geomechanical, operational, safety and economical risks before developing a …
Crown pillar design in highly dipping coal seam
Using a FISH program developed by Central Institute of Mining and Fuel Research (CIMFR), Dhanbad, India, in FLAC3D environment, the average factor of safety of different thickness of the crown pillars are determined and are given in Table 2, Table 3 for 13 seam and 12 seam respectively. From the past experience, in India, a safety factor of 1.0 is …
Crown pillar extraction with paste underhand stoping
analyses to assist with safe and efficient extraction of the crown pillar. Keywords: crown pillar, paste underhand, stoping 1 Introduction N3500 is a high-grade copper orebody situated in the northern part of the Enterprise Mine at Mount Isa Mines, located in northwest Queensland, Australia (Figure 1). Glencore's Mount Isa Mines has been in
Design of crown pillar thickness using finite element method …
The developed multivariate regression model is utilized for generating design/stability charts of pillars for different geo-mining conditions. These design charts can be …
A Stope Mining Design with Consideration of Hanging Wall …
This division allows separate assessments of the area above the crown pillar for open pit mining and below for underground mining. By considering geological factors, economics, and other relevant considerations, the authors aim to optimize extraction by employing the most suitable mining methods for each portion [12,13,14]. Pre-selecting the ...
Stability of Crown Pillar during Transition from …
The crown pillar faces a new challenge in dealing with the change in geo-mining conditions from open pit to underground. The vertical stresses acting on the pillar usually increases with increasing depth of mining, which is not …
A design philosophy for surface crown pillars of hard rock …
The design, while taking into consideration possible surface crown pillar settings and inherent characteristics, is founded on a step-by-step procedure starting with site investigations through …
Numerical Analysis of Sill and Crown Pillar Stability for …
A sill pillar is the horizontal part of the orebody left between the level drive and stope drive, whereas a crown pillar is the horizontal part of orebody left between stope roof and level drive as shown in Fig. 1.In cut and fill method of stoping, horizontal pillars are left at sill level to provide the base of the back filled material as well as to support the hanging wall and …
Numerical simulation study on stability analysis of crown pillar…
The transition from an open-pit to an underground space is inevitable to exploit deposits from greater depth. Crown pillar, a remnant ore usually left in between open-pit to underground mining that supports the terrain and aids in carrying out underground mining operations safely and its stability is vital. The design of crown pillar is majorly influenced by its …
Pillar stability assessment methodology for massive mines
each pillar in the mining layout. Having the area and perimeter of the pillars, the effective width can be calculated. Figure 2. Pillar outlines constructed using GEM4D. ... crown pillar span (Cs) is compared to the critical span (Sc). The Cs is estimated from the stope geometry
Numerical Simulation of Crown Pillar Behaviour in …
be left as a crown pillar to separate the two mining sections. Through numerical simulation in FLAC3D 7.0, stress distribution and failure mechanisms acting around the crown pillar were monitored as under-ground mining progresses. Effect of crown pillar geometrical parameters was evaluated, thus crown pillar thickness, span and dip. Further ...
(PDF) Crown Pillar Optimization for Surface to …
Proper dimensioning has to ensure the stability of open pit mine slopes and underground mine structural units as underground mining progresses to upper levels. Dimensional optimization of the...
Guidelines for use of the Scaled Span Method for …
Citing examples from the now well over 500 cases with over 70 failure records of crown collapses, this current paper examines some of these failures as background to explaining the empirical …
Determination of the Crown Pillar Thickness …
Crown pillar, a remnant ore usually left in between open-pit to underground mining that supports the terrain and aids in carrying out underground mining operations safely and its stability is vital.
CPillar | Easily analyze underground crown pillars
Crown Pillar Stability Analysis. ... Founded in 1996, Rocscience is a world leader in developing 2D and 3D software for civil, mining, and geotechnical engineers. As engineers ourselves, we know the importance of having reliable and easy-to-use software. That's why we constantly develop and refine our programs to make expert solutions that ...
Use of an artificial crown pillar in transition from open pit to
The process of mining the natural crown pillar and simultaneously replacing it with the artificial crown pillar was successfully executed by combining the strengths of empirical …