scholarly journals NUMERICAL MODELLING FOR UNDERGROUND MINING RELATED GEOTECHNICAL ISSUES

2013 ◽  
Vol 35 (3) ◽  
pp. 13-24
Author(s):  
L. Florkowska
Keyword(s):  
Numerical Modeling ◽  
Numerical Modelling ◽  
Continuous Monitoring ◽  
Underground Mining ◽  
Mining Areas ◽  
Geotechnical Problems ◽  
Mathematical And Numerical Modeling

Abstract Issues presented in this work relate to geotechnical problems that are specific to the mining areas. The paper discusses the methodology of mathematical and numerical modeling of these problems. Examples contained in the paper include: predicting the influence of mining exploitation on a detached building and evaluating the effectiveness of the building protection with the trench. Possible applications of numerical modeling as a tool to aid the continuous monitoring of the building state during the exploitation have also been discussed

Mathematical and Numerical Modeling of Liquids Dynamics in a Horizontal Capillary

2019 ◽  
pp. 66-78
Author(s):  
Giovanni Cavaccini ◽  
Vittoria Pianese ◽  
Alessandra Jannelli ◽  
Salvatore Iacono ◽  
Riccardo Fazio
Keyword(s):  
Numerical Modeling ◽  
Mathematical And Numerical Modeling

scholarly journals Factors Influencing Ore Recovery and Unplanned Dilution in Sublevel Open Stopes. Case study of Shaft No.4 at Konkola Mine, Zambia

2020 ◽  
Vol Special Issue (1) ◽  
Author(s):  
Kalunga Ngoma ◽  
Victor Mutambo
Keyword(s):  
Numerical Modelling ◽  
Principal Stress ◽  
Underground Mining ◽  
Poisson Ratio ◽  
High Stress ◽  
Geological Strength Index ◽  
Total Displacement ◽  
Ground Conditions ◽  
Geological Discontinuities ◽  
Major Principal Stress

Konkola Copper Mine’s Number 4 Shaft is a trackless underground mine applying sublevel open stoping (SLOS) mining method. Number 4 shaft wants to increase ore production from 1 million metric tonnes per annum to 3 million metric tonnes per annum in the next 5 years but ore recovery is 70% or less and dilution is 20% or more. In order to achieve the desired annual target of 3 million metric tonnes ore recovery should be increased from70% to (≥85%) and dilution should be reduced from 20% to (≤10%). Despite being one of the most used underground mining methods, the current SLOS has a challenge of high unplanned dilution. This paper reviews and evaluates parameters that influence recovery and unplanned dilution in sublevel open stopes and applies numerical modelling using PHASE2 software to establish the influence of stress environment on unplanned dilution at the mine. The input parameters for numerical modelling were: Uniaxial Compressive strength (UCS=170MPa), Geological Strength Index (GSI) =55, Young’s Modulus (E) =26000MPa, Hoek-Brown constant (s) =0.0067, Hoek-Brown constant (mi) =20 and Poisson ratio (v) =0.2 major principal stress (σ1) 39MPa, intermediate stress (σ2= 18MPa) and the minor principal stress (σ3= 15MPa). Results obtained from review of mine production records indicate that the main factors that influence unplanned dilution at Number 4 shaft are: poor ground conditions, lack of compliance to recommended stope designs, poor drilling and blasting practices, presence of geological discontinuities, adopted mining sequence of extracting high ore grade first that leads to creation of high stress blocks within the orebody and delayed mucking practice. Results obtained from PHASE 2D model indicate that total displacement of 90mm is recorded in the hangingwall hence influencing stope wall instability that leads to increased unplanned dilution. After stope extraction, it was observed that 60MPa of induced stress developed at the top right corner and 45-50 MPa at the crown pillar and right bottom corner of the stope.

scholarly journals Assesment Work Fatigue To Workers In Environment Underground Mining Areas Based On Fatigue Assesment Scale Questionnaires

2020 ◽  
Vol 202 ◽  
pp. 05013
Author(s):  
Siti Rachmawati ◽  
Miftaqul Aktsari ◽  
Anis Suryaningsih ◽  
Hashfi Hawali Abdul Matin ◽  
Iwan Suryadi
Keyword(s):  
Rating Scale ◽  
Underground Mining ◽  
Sleep Time ◽  
Type Ii ◽  
Work Time ◽  
Fatigue Assessment ◽  
Mining Areas ◽  
Hours Of Work ◽  
Fatigue Evaluation ◽  
Descriptive Method

Fatigue is recognized as a high potential risk for accidents and therefore an assessment of work fatigue is required. The purpose of this study is to describe the overall work fatigue assessment and based on work fatigue factors using questionnaires for the fatigue rating scale for workers in underground mining areas. This study used a descriptive method to describe the overall assessment of work fatigue and assessment of work fatigue based on factors related to fatigue using questionnaire scale fatigue assessment of workers in underground mining areas at PT. Y. Overall fatigue assessment based on fatigue evaluation questionnaire results obtained 54.55% of workers who experience fatigue. Fatigue assessment based on factors related to work fatigue shows that workers who tend to experience fatigue are> 45 years of age, <7 hours of sleep,> 5 years of work, 12 hours of work, supervisor type II / jumbo operator drill, jumbo drill operator, LHD operator, and service crew / helper jumbo drill, work climate> NAB (> 29.00 C) and noise> NAB (> 85 dB A). Underground mining workers tend to experience fatigue. The older the worker's age, the less sleep time, the longer the work period, the longer work time, the heavier the type of work, the hotter the working climate and the noisier it tends to experience fatigue.

scholarly journals Key Aspects of the Proper Formulation of the Model in Numerical Analysis of the Influence of Mining Exploitation on Buildings

2015 ◽  
Vol 36 (2) ◽  
pp. 17-28
Author(s):  
Lucyna Florkowska ◽  
Jan Walaszczyk
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Numerical Modelling ◽  
Underground Mining ◽  
Structural Characteristics ◽  
Number Of Factors ◽  
Proper Formulation ◽  
Key Aspects ◽  
The Impact ◽  
Complex Matter

Abstract Numerical modelling is an important tool used to analyse various aspects of the impact of underground mining on existing and planned buildings. The interaction between the building and the soil is a complex matter and in many cases a numerical simulation is the only way of making calculations which will take into consideration the co–existence of a number of factors which have a significant influence on the solution. The complexity of the matter also makes it a difficult task to elaborate a proper mathematical model – it requires both a thorough knowledge of geologic conditions of the subsoil and the structural characteristics of the building. This paper discusses the most important problems related to the construction of a mathematical model of a building-mining subsoil system. These problems have been collected on the basis of many years of experience the authors have in observing the surveying and tensometric deformations of the rock–mass and buildings as well as in mathematical and numerical modelling of the observed processes.

Validation of the accuracy of geodetic automated measurement system based on GNSS platform for continuous monitoring of surface movements in post-mining areas

2021 ◽  
Vol 112 (1) ◽  
pp. 47-57
Author(s):  
Violetta Sokoła-Szewioła ◽  
Zbigniew Siejka
Keyword(s):  
Continuous Monitoring ◽  
Surface Deformation ◽  
Optimal Solution ◽  
Satellite System ◽  
Reference Points ◽  
Hard Coal ◽  
Navigation Systems ◽  
Mining Areas ◽  
Global Navigation ◽  
Global Navigation Satellite

Abstract The problem involving the monitoring of surface ground movements in post-mining areas is particularly important during the period of mine closures. During or after flooding of a mine, mechanical properties of the rock mass may be impaired, and this may trigger subsidence, surface landslides, uplift, sinkholes or seismic activity. It is, therefore, important to examine and select updating methods and plans for long-term monitoring of post-mining areas to mitigate seismic hazards or surface deformation during and after mine closure. The research assumed the implementation of continuous monitoring of surface movements using the Global Navigation Satellite System (GNSS) in the area of a closed hard coal mine ‘Kazimierz-Juliusz’, located in Poland. In order to ensure displacement measurement results with the accuracy of several millimetres, the accuracy of multi-GNSS observations carried out in real time as a combination of four global navigation systems, Global Positioning System (GPS), Globalnaja Navigacionnaja Sputnikova Sistema (GLONASS), Galileo and BeiDou, was determined. The article presents the results of empirical research conducted at four reference points. The test observations were made in variants comprising measurements based on: GPS, GPS and GLONASS systems, GPS, GLONASS and Galileo systems, GPS, GLONASS, Galileo and BeiDou systems. For each adopted solution, daily measurement sessions were performed using the RTK technique. The test results were subjected to accuracy analyses. Based on the obtained results, it was found that GNSS measurements should be carried out with the use of three navigation systems (GPS, GLONASS, Galileo), as an optimal solution for the needs of continuous geodetic monitoring in the area of the study.

Sign in / Sign up

Export Citation Format

Share Document