scholarly journals An Attempt at Evaluation of the Remnant Influence On the Occurrence of Seismic Phenomena in a Room-and-Pillar Mining System with Roof Deflection

2017 ◽  
Vol 39 (2) ◽  
pp. 3-16 ◽  
Author(s):  
Karolina Adach-Pawelus ◽  
Jan Butra ◽  
Daniel Pawelus
Keyword(s):  
Numerical Modeling ◽  
Underground Mining ◽  
High Energy ◽  
Numerical Calculations ◽  
Copper Ore ◽  
Mining System ◽  
Left Behind ◽  
Room And Pillar Mining ◽  
Very High Energy ◽  
Pillar Mining

Abstract Experience gained until now underground mining worldwide and in Poland indicates that remnants may have an impact on the occurrence of seismic phenomena. Remnants are stress concentration sites encompassing both the deposit and the layers of rock mass located above and below the undisturbed rock. In the case where stresses in the remnant exceed its strength, it may collapse, and under unfavourable geomechanical conditions, stress-induced rockburst may occur. Remnants may also cause breaking of strong roof layers above their edges, which results in the occurrence of high-energy shocks (Salustowicz [30], Adach [3], Adach and Butra [4]). This article presents the possibility of utilizing numerical modeling to evaluate the influence of remnant upon the occurrence of seismic phenomena. The results of numerical calculations performed for a model room-and-pillar mining system with roof deflection under the conditions of copper ore mines in the Legnica-Głogów Copper District (LGOM) are presented. Numerical calculations in a plane strain state were performed by means of Phase2 v. 8.0 software for the analyzed mining system in which remnant was left behind. The results of numerical modeling showed that sudden fracturing of roof layers above the mined out space may occur on the edge of the remnant. This may cause a shock with very high energy, and under the appropriate conditions, this may lead to the rockburst phenomenon.

scholarly journals IMPROVED UNDERGROUND MINING DESIGN METHOD FOR ESTONIAN OIL SHALE DEPOSIT

2005 ◽  
Vol 1 ◽  
pp. 270
Author(s):  
Jyri-Rivaldo Pastarus
Keyword(s):  
Factor Of Safety ◽  
Oil Shale ◽  
Underground Mining ◽  
Design Method ◽  
Influence Factors ◽  
Mining System ◽  
Room And Pillar Mining ◽  
Mathematical Formulas ◽  
Pillar Mining ◽  
Mining Design

The paper deals with the improved mining design method for Estonian oil shale mines, where the room-and-pillar mining system is used. Design of mining block parameters is based on the instruction used in Estonian oil shale mines. The factor of safety is very large. Consequently, the design method does not take into consideration all the influence factors. It is determined the supplementary influence factors and given the mathematical formulas. In this case the factor of safety is reduced up to 1.2. The improved mining design method is of particular interest for practical purposes.

scholarly journals Application of Hydraulic Backfill for Rockburst Prevention in the Mining Field with Remnant in the Polish Underground Copper Mines

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3869
Author(s):  
Karolina Adach-Pawelus ◽  
Daniel Pawelus
Keyword(s):  
Great Depth ◽  
Mining System ◽  
Rockburst Hazard ◽  
Left Behind ◽  
Room And Pillar Mining ◽  
Mining Conditions ◽  
Copper Mines ◽  
Pillar Mining ◽  
Rock Mass Deformation ◽  
High Level

In the polish underground copper mines owned by KGHM Polska Miedz S.A, various types of room and pillar mining systems are used, mainly with roof deflection, but also with dry and hydraulic backfill. One of the basic problems associated with the exploitation of copper deposits is rockburst hazard. Aa high level of rockburst hazard is caused by mining the ore at great depth in difficult geological and mining conditions, among others, in the vicinity of remnants. The main goal of this study is to investigate how hydraulic backfill improves the geomechanical situation in the mining filed and reduce rockburst risk in the vicinity of remnants. Numerical modeling was conducted for the case study of a mining field where undisturbed ore remnant, 40 m in width, was left behind. To compare the results, simulations were performed for a room and pillar mining system with roof deflection and for a room and pillar mining system with hydraulic backfill. Results of numerical analysis demonstrate that hydraulic backfill can limit rock mass deformation and disintegration in the mining field where remnants have been left. It may also reduce stress concentration inside or in the vicinity of a remnant, increase its stability, as well as prevent and reduce seismic and rockburst hazards. Hydraulic backfill as a local support stabilizes the geomechanical situation in the mining field.

scholarly journals MINING BLOCK STABILITY PREDICTION BY THE MONTE CARLO METHOD

2006 ◽  
Vol 1 ◽  
pp. 185
Author(s):  
O. Nikitin
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Oil Shale ◽  
Ground Surface ◽  
Mining System ◽  
Room And Pillar Mining ◽  
The Monte Carlo Method ◽  
Geological Conditions ◽  
Pillar Mining ◽  
Failure Prognosis

This paper analyses the stability of the mining blocks by the Monte Carlo method in Estonian oil shale mines, where the room-and-pillar mining system is used. The pillars are arranged in a singular grid. The oil shale bed is embedded at the depth of 40-75 m. The processes in overburden rocks and pillars have caused the subsidence of the ground surface. Visual Basic for Application was used for the modeling. Through Monte Carlo simulation, room-and-pillar stable parameters can be calculated. Model allows determination of the probability of spontaneous collapse of the pillars and surface subsidence by the parameters of registered collapsed mining blocks. Proposed method suits as an express-method for stability analysis and failure prognosis. It is applicable in different geological conditions, where the room-and-pillar mining system is used.

Deformation Characteristics of a Technological Pillar in the Chamber-Pillar Mining System/Charakterystyka Deformacyjna Filara Technologicznego W Komorowo-Filarowym Systemie Eksploatacji

2014 ◽  
Vol 59 (2) ◽  
pp. 323-335
Author(s):  
Wiesław Grzebyk ◽  
Lech Stolecki
Keyword(s):  
Underground Mining ◽  
Measurement Techniques ◽  
Measurement Data ◽  
Deformation Characteristics ◽  
Mining System ◽  
The Face ◽  
Pillar Mining ◽  
In Situ Observations ◽  
Mining Works

Abstract The article presents the suitability of the new measurement techniques for monitoring deformations of the technological pillars and fragments of the face in underground mining. The conducted observations concerned the mined pillar located in the lead of mining field G-3/4 of Rudna mine (mine belongs to KGHM Polska Miedź S.A.) in a situation of constant progress of mining works in its direction. The observations conducted underground provided results demonstrating the suitability of the applied observation techniques in this area. The obtained measurement data directly describe the volumetric changes which form the basis for assessing the stress of the rock formation. This issue is well recognised based on the tests on rock samples. Further studies should concern the transfer of these experiences to the results of in situ observations.

scholarly journals LONG-TERM STABILITY MONITORING OF THE MINING BLOCKS IN ESTONIAN OIL SHALE MINES

2006 ◽  
Vol 1 ◽  
pp. 206
Author(s):  
J.-R. Pastarus
Keyword(s):  
Influence Factors ◽  
Monitoring Methods ◽  
Mining System ◽  
Term Stability ◽  
Long Term Stability ◽  
Room And Pillar Mining ◽  
Convergence Method ◽  
Pillar Mining

This paper deals with long-term stability prediction and monitoring methods by room-and-pillar mining system. Roof-to-floor convergence and conditional thickness methods suit for calculations. They allow determination of the location, area and time of the collapse in a mining block. The uncertainty in time is less than 10 % at the 95 % confidence level. Roof-to-floor convergence method is preferred; it takes into consideration all the geological and mining feature in the critical area. Conditional thickness method demands supplementary investigations, determination of the influence factors on the process. The applicability of these methods is clearly demonstrated.

Optimizing cut-out distance for maximum coal productivity

SIMULATION ◽  
2018 ◽  
Vol 95 (6) ◽  
pp. 545-559
Author(s):  
Angelina Anani ◽  
Wedam Nyaaba ◽  
Asieh Hekmat ◽  
Eduardo A Córdova
Keyword(s):  
Discrete Event ◽  
Operating Cost ◽  
Mining System ◽  
Fleet Size ◽  
Continuous Miner ◽  
Event Simulation ◽  
Room And Pillar Mining ◽  
Maximum Cut ◽  
Increase Productivity ◽  
Pillar Mining

The need to increase productivity has led to innovations in highly mechanized equipment such as the continuous miner (CM). However, often times the CM is underutilized, resulting in loss of productivity and increased operating cost. The objective of this study is to apply a simulation tool to evaluate if optimizing support systems, such as cut-out distance, fleet size, and panel dimensions, can maximize CM utilization and productivity. Discrete event simulation is used to analyze different cut-out distances for a room and pillar mining system. The results show that an 11-entry panel width with a fleet size of three shuttle cars is optimum for the variable cut-out distances examined. The utilization and production rate also increases by 6% at the maximum cut-out distance.

scholarly journals The Seismic Shock Prediction Algorithm based on the Rock Mass behaviour data

2021 ◽  
Author(s):  
Tomasz Moroń ◽  
Bożena Staruch ◽  
Bogdan Staruch ◽  
Sławomir Tomaszewski ◽  
Agnieszka Wyłomańska
Keyword(s):  
Rock Mass ◽  
Seismic Activity ◽  
Underground Mining ◽  
High Energy ◽  
Ore Deposits ◽  
Prediction Algorithm ◽  
Work Safety ◽  
Copper Ore ◽  
Seismic Shock ◽  
Behaviour Data

KGHM S.A. exploits copper ore deposits in underground mining facilities. As a result of this operation the seismic activity of the rock mass is induced. One of the symptoms of seismic activity of the rock mass is the occurrence of high energy seismic shocks. These phenomena can lead to severe destructions in mine workings. Resulting from that is a threat to work safety in the area of seismic shock occurrence and risk of damage to mine's property. Particularly strong seismic shocks may also pose a threat to objects on the surface. The level of seismic activity of the rock mass depends on many factors that can be divided into factors related to the environment in which the operation is carried out and factors related to methods of conducting the operation. In the report authors propose an algorithm for prediction of the occurrence of seismic shocks with a given energy.

EXPERIENCE OF IMPROVING COAL MINING RECOVERY FACTOR IN ROOM-AND-PILLAR MINING SYSTEM

Ugol ◽  
2018 ◽  
pp. 55-59
Author(s):  
A.V. Aikin ◽  
◽  
I.P. Trandin ◽  
A.S. Pozolotin ◽  
M.V. Lysenko ◽  
...  
Keyword(s):  
Coal Mining ◽  
Recovery Factor ◽  
Mining System ◽  
Room And Pillar Mining ◽  
Pillar Mining

scholarly journals EVALUATION OF THE STABILITY OF A TEMPORARY PILLAR WHEN MIINING ORE HORIZONS WITH BACKFILLING AND CAVING

2021 ◽  
Vol 2 (3) ◽  
pp. 123-134
Author(s):  
Sergey Yu. Vasichev ◽  
Alexander A. Neverov
Keyword(s):  
Raw Materials ◽  
Ore Deposits ◽  
Geomechanical Model ◽  
Mining System ◽  
Room And Pillar Mining ◽  
Mining Front ◽  
Pillar Mining ◽  
The Stability ◽  
Enclosing Rocks ◽  
Safe Mining

A method is proposed for mining thick and flat ore deposits at great depths in conditions of a decline in the value of extracted mineral raw materials. It is found that safe mining with solidifying backfill and caving is achieved by determining the parameters of stable spans of rooms, in place of which artificial supports and temporary ore pillars are formed. These pillars are recovered with a lag behind room-and-pillar mining by caving of ore and enclosing rocks. It is shown that, depending on the type of geomechanical model of geomedium and orientation of the initial natural stresses acting in the rock mass relative to the mining front, the field of application of the mining system is limited by the depth and parameters of excavation. Predictive areas of possible rock failure are determined applicably to rock masses with different degree of disturbance.

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