Our Offered Machines to you

Who are in extremely love with eco friendly system..

pillars in hard rock mining excavation - Crescendo

Slightly concave pillar ribs formed as a result of minor spalling of the hard, brittle rock. of bench mining, for a pillar with a width-to-height ratio of 1.5 based on the results of the excavation dimensions, rock jointing characteristics, rock mass classification, and excavation stability conditions were recorded.

More

Pillar design - QueensMineDesignWiki

Shaft Pillars. Shaft pillars are the most important excavation in an underground mine and must be protected above everything else. Failure criteria includes strain limits for deformation, stress limits for failure of rock in shaft sidewalls, and for high speed hoisting. For strain limits of deformation, tilting and kinking can be used as guides.

More

(PDF) An approach to hard rock pillar design at the ...

One of the most challenging safety problems in underground hard rock mines is pillar stability during mining operation. This paper presents an assessment of J48 and SVC application for pillar ...

More

THE DESIGN AND BEHAVIOUR OF CRUSH PILLARS ON THE

Mining practices are aimed at maximising the extraction of a particular orebody without compromising safety. Crush pillar mining appears to be a method unique to South African hard rock mines. These pillar systems are used in shallow and intermediate depth platinum stopes. It allows for a

More

(PDF) Pillar stability assessment approach for

There is little experience with mechanized or non-explosive excavation methods in hard rock metalliferous underground mining. Therefore, the perceived benefits of mechanized excavation over drill-and-blast must be demonstrated. The application of numerical modeling in rock pillar stability analysis has recently become popular.

More

Pillar Strength in Underground Stone Mines in the United ...

The design of slender pillars in hard brittle rocks has received considerable attention in recent years [5–8]; however, a widely accepted design method does not exist for pillars in stone mines. research described in this paper had the objective to reduce the rock fall hazard and the potential for multiple pillar

More

Development and evaluation of artificial

01-10-2018  Comparing with traditional artificial supports, the expandable pillars provide higher initial support stresses to stope roofs and they continue to carry loads in a strain-hardening manner. As a result, the expandable pillars can stabilize an excavation with small roof deformation.

More

(PDF) An approach to hard rock pillar design at

One of the most challenging safety problems in underground hard rock mines is pillar stability during mining operation. This paper presents an assessment of J48 and SVC application for pillar ...

More

(PDF) Pillar stability assessment approach for

There is little experience with mechanized or non-explosive excavation methods in hard rock metalliferous underground mining. Therefore, the perceived benefits of mechanized excavation over drill-and-blast must be demonstrated. The application of numerical modeling in rock pillar stability analysis has recently become popular.

More

Pillar Strength in Underground Stone Mines in the United ...

The design of slender pillars in hard brittle rocks has received considerable attention in recent years [5–8]; however, a widely accepted design method does not exist for pillars in stone mines. research described in this paper had the objective to reduce the rock fall hazard and the potential for multiple pillar

More

THE DESIGN AND BEHAVIOUR OF CRUSH PILLARS ON THE

Mining practices are aimed at maximising the extraction of a particular orebody without compromising safety. Crush pillar mining appears to be a method unique to South African hard rock mines. These pillar systems are used in shallow and intermediate depth platinum stopes. It allows for a

More

v118n7a10 Effect of dip on pillar strength

In hard rock underground mines, pillars are typically left between the openings (stopes) to maintain the stability of the openings. They are usually rib pillars (vertical or near vertical) or crown/sill pillars (horizontal and near horizontal). Pillars need to be adequately designed to

More

Excavation unloading‐induced fracturing of hard rock ...

observed in several deep hard rock mines.31,35,63 Typically, rock burst can be classified into three types, namely fault slip, pillar, and strain rock burst.29,34 Of these categories, strain rock burst is the most common dynamic hazard encountered in underground engineering, especially near excavation boundaries of hard and intact rockmass. The

More

Numerical Analysis on Failure Modes and

Mine pillars are in situ rock left after mining to ensure mine safety. The determination of pillar sizes dictates the cost of mining and mine safety. Pillar instability refers to the compressional-shear or splitting failure under uniaxial stresses when external loading reaches a limit value.

More

(PDF) Stability of boundary pillars for transition

The appropriate size and stability of insulating pillar, which are transition stretch shifting from shallow excavation to deep mining, are very important for safe production of deep mine.

More

Hard Rock Miner's Handbook - Stantec

HARD ROCK MINER’S HANDBOOK 2008 Stantec Consulting Ltd. STANTEC CONSULTING . Hard Rock Miner’s Handbook . by Jack de la Vergne . TITLE . Hard Rock Miner’s Handbook, Edition 5 . Copyright © 2008 Stantec Consulting Ltd. 10160 – 112 Street • Edmonton, Alberta • Canada . Phone (780) 917- 7000 • Fax (780) 7330 . Hard Rock Miner’s Handbook, Edition 3

More

Lecture 4: Underground Mining - SlideShare

02-11-2011  Choice of mining method Underground Mining Methods Soft rock Mining Methods Blast mining Shortwall mining Coal Skimming (or Sink and Float) method Hard rock Mining Methods Stoping 1) Room and pillar 2) Bench and Fill (B F) stoping 3) Cut and Fill (C F) stoping 4) Stull stoping 5) Square-set stoping 6) Shrinkage stoping 7) Long-hole Open stoping 8) Vertical Crater Retreat (VCR)

More

PILLAR DESIGN IN BRITTLE ROCKS

A common mining practice involves leaving rack "pillars" between mine openings to maintain the stability of the openings. A grellt deai of work has been done on the stability of coal pillars however, relatively little work has been done on the stability of hard-rock pillars.

More

(PDF) Pillar stability assessment approach for

There is little experience with mechanized or non-explosive excavation methods in hard rock metalliferous underground mining. Therefore, the perceived benefits of mechanized excavation over drill-and-blast must be demonstrated. The application of numerical modeling in rock pillar stability analysis has recently become popular.

More

Pillar Stability Assessment Approach For

Pillars are created in most mining methods. In room-and-pillar and block cave mining, pillar stability is critical for success. These pillars may be recovered at some stage in the mining process or left behind depending on the type of pillar and its economic value.

More

A numerical investigation of rock pillar failure

An extensive numerical analysis was carried out to study the pillar deformation and failure process under natural loading conditions. Effects of pillar geometry and pillar strength parameters on pillar behavior were investigated for hard rock material typical of Canadian mining conditions.

More

THE DESIGN AND BEHAVIOUR OF CRUSH PILLARS ON THE

Mining practices are aimed at maximising the extraction of a particular orebody without compromising safety. Crush pillar mining appears to be a method unique to South African hard rock mines. These pillar systems are used in shallow and intermediate depth platinum stopes. It allows for a

More

v118n7a10 Effect of dip on pillar strength

In hard rock underground mines, pillars are typically left between the openings (stopes) to maintain the stability of the openings. They are usually rib pillars (vertical or near vertical) or crown/sill pillars (horizontal and near horizontal). Pillars need to be adequately designed to

More

Numerical modeling of time-dependent spalling of

Introduction. Rock pillars are commonly used in underground mines to maintain stability of excavations. The estimation of the strength of rock pillars is important for mining engineering, but it is a challenging task because many factors such as geometry of pillars, in-situ stress, variation of rock types and rock mass quality influence pillar strength.

More

Decreasing Mining Losses for the Room and

The estimated total costs of mining the rock pillar and replacing it with a wooden crib filled with waste rocks constitute 80% to 85% of the value of the metals contained in the pillar. For mining excavations where there are no useful minerals, there is no need to take them to the surface; these rocks can be used to fill the wooden cribs.

More

Numerical Analysis on Failure Modes and

Mine pillars are in situ rock left after mining to ensure mine safety. The determination of pillar sizes dictates the cost of mining and mine safety. Pillar instability refers to the compressional-shear or splitting failure under uniaxial stresses when external loading reaches a limit value.

More

Hard Rock Miner's Handbook - Stantec

HARD ROCK MINER’S HANDBOOK 2008 Stantec Consulting Ltd. STANTEC CONSULTING . Hard Rock Miner’s Handbook . by Jack de la Vergne . TITLE . Hard Rock Miner’s Handbook, Edition 5 . Copyright © 2008 Stantec Consulting Ltd. 10160 – 112 Street • Edmonton, Alberta • Canada . Phone (780) 917- 7000 • Fax (780) 7330 . Hard Rock Miner’s Handbook, Edition 3

More

Numerical Analysis of Hard Rock Pillars using the

Pillars are the portion of in situ rock left between the adjacent openings to maintain the stability of excavations. Conditions of equilibrium require that the loads previously carried by the excavated rocks be transferred to the pillars resulting in elevated stresses within the pillar.

More

THE DESIGN AND BEHAVIOUR OF CRUSH PILLARS ON THE

Mining practices are aimed at maximising the extraction of a particular orebody without compromising safety. Crush pillar mining appears to be a method unique to South African hard rock mines. These pillar systems are used in shallow and intermediate depth platinum stopes. It allows for a

More

Influence of mining excavation on energy redistribution ...

Influence of mining excavation on energy redistribution and rockburst potential G. Lafont, Yann Gunzburger, H.S. Mitri, ... become an integral part of most hard rock deep mines in an effort to characterize mining induced seismicity (Trifu, 2009, Archibald, ... a type of rockburst caused by the burst of a pillar, a face or a floor in a

More

v117n6a3 Strapping of pillars with cables to enhance ...

pillars that initially appear stable but are subjected to smaller factors of safety caused by poor blasting or poor excavation control. The application and studies of similar techniques have very seldom been reported in the literature. In South Africa, a few cases exist of hard rock pillar failure where attempts were made to strengthen the pillars.

More

Hard rock pillar strength estimation an applied

Two new pillar strength estimation methods for hard rock mine pillars are presented in this thesis. 31 pillar case histories of the database that was used to develop these new formulae were acquired during a cooperative study, entitled “Ground Stability Guidelines for the Extraction of Barrier Pillars in Hard Rock Mines”, between Westmin Resources Ltd. and The Canadian Centre for Mineral and Energy Technology (CANMET). 147 additional case histories were acquired from six documented hard ...

More

Hardrock Mining TechniquesUnderground

Room and Pillar mining : Room and pillar mining is commonly done in flat or gently dipping bedded ore bodies. Pillars are left in place in a regular pattern while the rooms are mined out. In many room and pillar mines, the pillars are taken out starting at the farthest point from the stope access, allowing the roof to collapse and fill in the stope.

More

Excavation unloading‐induced fracturing of hard rock ...

observed in several deep hard rock mines.31,35,63 Typically, rock burst can be classified into three types, namely fault slip, pillar, and strain rock burst.29,34 Of these categories, strain rock burst is the most common dynamic hazard encountered in underground engineering, especially near excavation boundaries of hard and intact rockmass. The

More

Hard Rock Miner's Handbook - Stantec

HARD ROCK MINER’S HANDBOOK 2008 Stantec Consulting Ltd. STANTEC CONSULTING . Hard Rock Miner’s Handbook . by Jack de la Vergne . TITLE . Hard Rock Miner’s Handbook, Edition 5 . Copyright © 2008 Stantec Consulting Ltd. 10160 – 112 Street • Edmonton, Alberta • Canada . Phone (780) 917- 7000 • Fax (780) 7330 . Hard Rock Miner’s Handbook, Edition 3

More

Room pillar mining OL.pptx - ROOM AND

In hard rock, pillars are usually much smaller horizontally than rooms. In soft rock and coal mines, they are usually much larger. It is usually used for relatively flat-lying deposits, such as those that follow a particular stratum. The key to the successful room and pillar mining is selecting the optimum pillar size.

More

Lecture 4: Underground Mining - SlideShare

02-11-2011  Stope and Retreat vs. Stope and Fill Retreat Retreat is a term used to reference the final phase of an underground mining technique. This involves excavating supporting pillars Once a deposit has been exhausted using this method, the pillars that were left behind initially are removed (or 'pulled‘) retreating back towards the mine's entrance. After the pillars are removed, the roof (or back) is allowed to collapse behind the mining area. Pillar

More