Selected Methods of Rock Structure Disintegration to Control Mining Hazards / Wybrane Metody Dezintegracji Struktury Skał Dla Zwalczania Zagrożeń Górniczych

2015 ◽  
Vol 60 (3) ◽  
pp. 807-824
Author(s):  
Józef Kabiesz ◽  
Adam Lurka ◽  
Jan Drzewiecki
Keyword(s):  
Rock Mass ◽  
Seismic Waves ◽  
Underground Mining ◽  
Practical Consideration ◽  
Work Safety ◽  
Rock Structure ◽  
Mining Hazards ◽  
New Type ◽  
Specific Temperature ◽  
Temperature And Pressure

Abstract Natural hazards are inseparable element of underground mining, particularly of coal mining process. They are combated on a regular basis by many measures and effectiveness of these measures determines work safety in mines. Attempts to improve the effectiveness, presented in the paper is based on interference of seismic waves generated by blasting in a selected area of the rock mass and on modification of blasting technology. Preliminary results of detonating classical and new type of explosives in specific temperature and pressure conditions are analyzed. Theoretical and practical consideration of obtaining an interference effect of seismic waves is discussed. A device for making systems of starting notches and a construction of a chamber to test explosives are presented.

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.

ESEM - A multipurpose surface Electron Microscope

1986 ◽  
Vol 44 ◽  
pp. 632-633 ◽  
Author(s):  
G.D. Danilatos
Keyword(s):  
Electron Microscope ◽  
Room Temperature ◽  
Environmental Scanning ◽  
Gas Composition ◽  
Saturated Water Vapor ◽  
Surface Electron ◽  
Current State ◽  
Saturated Water ◽  
New Type ◽  
Temperature And Pressure

Over recent years a new type of electron microscope - the environmental scanning electron microscope (ESEM) - has been developed for the examination of specimen surfaces in the presence of gases. A detailed series of reports on the system has appeared elsewhere. A review summary of the current state and potential of the system is presented here.The gas composition, temperature and pressure can be varied in the specimen chamber of the ESEM. With air, the pressure can be up to one atmosphere (about 1000 mbar). Environments with fully saturated water vapor only at room temperature (20-30 mbar) can be easily maintained whilst liquid water or other solutions, together with uncoated specimens, can be imaged routinely during various applications.

THE IDENTIFICATION OF PARAMETERS OF THEORIES USED FOR PROGNOSES OF POST MINING DEFORMATIONS BY MEANS OF PRESENT SOFTWARE / IDENTYFIKACJA WARTOŚCI PARAMETRÓW TEORII PROGNOZOWANIA WPŁYWÓW PRZY WYKORZYSTANIU WSPÓŁCZESNYCH NARZĘDZI INFORMATYCZNYCH

2013 ◽  
Vol 58 (4) ◽  
pp. 1347-1357 ◽  
Author(s):  
Roman Ścigała
Keyword(s):  
Rock Mass ◽  
Land Surface ◽  
Underground Mining ◽  
Transient State ◽  
Computer Programs ◽  
Asymptotic State ◽  
Software System ◽  
Practical Utilization ◽  
Identification Of Parameters ◽  
Graphical Processing

Abstract The characteristic of specialized computer programs has been presented, serving for identification of W. Budryk-S. Knothe theory parameters, used for description of asymptotic state of post-mining deformations, as well as for transient state. The software is the result of several years of authors’ work. It is a part of complete software system designed for forecasting of underground mining influences on the rock mass and land surface and graphical processing of calculations results. Apart from software description, a short example of its practical utilization has been attached.

A periodic seismic isolation foundation with an extremely broad low-frequency attenuation zone: Theoretical analysis and experimental verification

2021 ◽  
pp. 136943322110646
Author(s):  
Peng Zhou ◽  
Shui Wan ◽  
Xiao Wang ◽  
Yingbo Zhu ◽  
Muyun Huang
Keyword(s):  
Seismic Isolation ◽  
Seismic Waves ◽  
Periodic Structures ◽  
Finite Size ◽  
Low Frequency ◽  
Bridge Structure ◽  
Engineering Structures ◽  
P Waves ◽  
New Type ◽  
Dominant Frequencies

The attenuation zones (AZs) of periodic structures can be used for seismic isolation design. To cover the dominant frequencies of more seismic waves, this paper proposes a new type of periodic isolation foundation (PIF) with an extremely wide low-frequency AZ of 3.31 Hz–17.01 Hz composed of optimized unit A with a wide AZ and optimized unit B with a low-frequency AZ. The two kinds of optimized units are obtained by topology optimization on the smallest periodic unit with the coupled finite element-genetic algorithm (GA) methodology. The transmission spectra of shear waves and P-waves through the proposed PIF of finite size are calculated, and the results show that the AZ of the PIF is approximately the superposition of the AZs of the two kinds of optimized units. Additionally, shake tests on a scale PIF specimen are performed to verify the attenuation performance for elastic waves within the designed AZs. Furthermore, numerical simulations show that the acceleration responses of the bridge structure with the proposed PIF are attenuated significantly compared to those with a concrete foundation under the action of different seismic waves. Therefore, the newly proposed PIF is a promising option for the reduction of seismic effects in engineering structures.

A New Type of Muffler Based on Microperforated Tubes

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
S. Allam ◽  
M. Åbom
Keyword(s):  
Acoustic Impedance ◽  
Noise Control ◽  
Wave Impedance ◽  
Sound Waves ◽  
Submillimeter Range ◽  
Perforated Plates ◽  
Characteristic Wave ◽  
Standard Temperature ◽  
New Type ◽  
Temperature And Pressure

Microperforated plate (MPP) absorbers are perforated plates with holes typically in the submillimeter range and perforation ratios around 1%. The values are typical for applications in air at standard temperature and pressure (STP). The underlying acoustic principle is simple: It is to create a surface with a built in damping, which effectively absorbs sound waves. To achieve this, the specific acoustic impedance of a MPP absorber is normally tuned to be of the order of the characteristic wave impedance in the medium (∼400 Pa s/m in air at STP). The traditional application for MPP absorbers has been building acoustics often combined with a so called panel absorber to create an absorption peak at a selected frequency. However, MPP absorbers made of metal could also be used for noise control close to or at the source for noise control in ducts. In this paper, the possibility to build dissipative silencers, e.g., for use in automotive exhaust or ventilation systems, is investigated.

scholarly journals Automatic Monitoring System Designed for Controlling the Stability of Underground Excavation

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Piotr MAŁKOWSKI ◽  
Zbigniew NIEDBALSKI ◽  
Łukasz BEDNAREK
Keyword(s):  
Rock Mass ◽  
Underground Mining ◽  
Automatic Monitoring ◽  
Mass Movements ◽  
Support Design ◽  
Automatic Monitoring System ◽  
Underground Workings ◽  
The Stability ◽  
Technical Solutions ◽  
The Given

Ensuring the stability of mining excavations is a crucial aspect of underground mining. For thispurpose, appropriate shapes, dimensions, and support of workings are designed for the given mining andgeological conditions. However, for the proper assessment of the adequacy of the used technical solutions,and the calibration of the models used in the support design, it is necessary to monitor the behavior of theexcavation. It should apply to the rock mass and the support. The paper presents the automatic systemdesigned for underground workings monitoring, and the example of its use in the heading. Electronicdevices that measure the rock mass movements in the roof, the load on the standing support, and on bolts,the stress in the rock mass, are connected to the datalogger and can collect data for a long of time withoutany maintenance, also in hard-to-reach places. This feature enables the system to be widely used, inparticular, in excavations in the vicinity of exploitation, goafs, or in the area of a liquidated exploitationfield.

scholarly journals Determination and quality classification of rock mass of the Diatomite mine, Algeria

2021 ◽  
Vol 1 ◽  
pp. 17-24
Author(s):  
Abdessattar LAMAMRA ◽  
◽  
Dmitriy Leonidovich NEGURITSA ◽  
Samir BEDR ◽  
Ariant A. REKA ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Rock Mass ◽  
Underground Mining ◽  
Physical And Mechanical Properties ◽  
Friction Angle ◽  
Classification Systems ◽  
Natural Phenomenon ◽  
Underground Structures ◽  
Dilatancy Angle ◽  
Mining Work

Reserch relaevance. Most ground movements are generally due to rock instability, this natural phenomenon poses a risk to humanity. The properties of the rock mass directly influence the type of movement especially in underground structures. Research aim. Our goal is to characterize and classify the rock mass of diatomite from the sig mine using geomechanical classification systems such as the RQD and RMR in order to determine the quality of the rocks in the sig mine Western Algeria from the determination of the physical and mechanical properties. Methodology. In this article, the characterization analysis of the diatomite rock mass of the sig mine was carried out. First, determinations of the physical properties and carried out the triaxial test to determine the mechanical properties (young’s modulus, the friction angle, the dilatancy angle, the cohesion, the poisson’s ratio). Secondly to classify the deposit and give a recommendation to avoid stability problems. Research results. The results from physical and mechanical analyzes, it can be said that the nature of the rock present in the diatomite (underground mine) does not have enough resistance. Conclusion. Our study definitively proves that the rock mass of sig diatomite is of very low quality and it will be very dangerous for the underground mining work of the mine especially in places where the mineralized layer is very deep. And we suggest to replace the mining technique room and pillar currently used in the diatomite mine and put another mining method which includes roof support system to ensure the safety both of the miners and the equipment.

scholarly journals ИССЛЕДОВАНИЕ ВОЗМОЖНОСТИ РЕГИСТРАЦИИ МЕДЛЕННЫХ ДЕФОРМАЦИОННЫХ ВОЛН ЛАЗЕРНЫМ ДЕФОРМОГРАФОМ

2019 ◽  
Author(s):  
I.Y. Rasskazov ◽  
V.A. Lugovoy ◽  
D.I. Tso
Keyword(s):  
Rock Mass ◽  
Experimental Research ◽  
Seismic Waves ◽  
Gulf Of Alaska ◽  
Rock Massif ◽  
Experimental Investigations ◽  
Correct Interpretation ◽  
Acoustic Activity ◽  
Laser Measurements ◽  
Deformation Processes

В статье представлены экспериментальные исследования по обнаружению медленных деформационных волн, интенсифицирующих геомеханические процессы в массиве горных пород, с применением высокочувствительных лазерных измерений. Проведены результаты экспериментальных исследований по оценке влияния удаленных землетрясений на состояние горного массива Стрельцовского рудного поля, регистрации удаленных землетрясений и их предвестников. Приведены результаты регистрации землетрясения в заливе Аляска. Установлено влияние удаленных землетрясений на акустическую активность горного массива, которое проявляется в виде значительного увеличения количества акустических событий и их энергии после регистрации сейсмической волны. Выявлено, что наличие деформационных и сейсмических волн от удаленных землетрясений можно отнести к дополнительным факторам, инициирующим деформационные процессы в горном массиве. Своевременная регистрация данных волн и корректная их интерпретация позволят значительно повысить достоверность прогноза энергетических геодинамических событий в удароопасных массивах горных пород при разработке месторождений в целях предотвращения катастрофических событий.The article presents experimental investigations on the detection of slow waves intensifying geomechanical processes in rock massif, with the application of highsensitivity laser measurements. The results of experimental research for the evaluation of remote earthquakes impact on the condition of rock massif of Streltsovskoe ore field, registration of remote earthquakes and their forerunners are given. The results of the earthquake in the Gulf of Alaska, is represented in the article. The influence of distant earthquakes on the rock mass acoustic activity, which manifests itself in the form of a significant increase in the number of acoustic events and their energy after the registration of a seismic wave, is established. It is revealed that the presence of deformation and seismic waves from distant earthquakes can be attributed to additional factors that initiate deformation processes in the rock massif. Timely recording of these waves and their correct interpretation will significantly improve the accuracy of the prediction of energy geodynamic events in shockhazardous rock masses when developing fields in order to prevent catastrophic events.

Prediction of the Ground Vibration Rate during Large-scale Explosions in the Underground Conditions

2021 ◽  
pp. 41-45
Author(s):  
V.N. Tyupin ◽  
Keyword(s):  
Rock Mass ◽  
Large Scale ◽  
Underground Mining ◽  
Calculated Data ◽  
Ground Vibration ◽  
Open Pit ◽  
Vibration Velocity ◽  
Earth Surface ◽  
Seismic Safety ◽  
The Earth

At present, to ensure seismic safety in massive explosions, the analytical dependence of the determination of the vibration velocity of M.A. Sadovsky rock mass is mainly used. This dependence is widely used in the creation of seismic-safe technologies for mineral deposits open-pit and underground mining. However, scientific research and production experience showed that the rate of oscillation depends on the energy parameters of the explosive, the diameter and length of its charges, the number of simultaneously exploded charges, the number of deceleration stages, the deceleration interval, etc. The purpose of this article is to predict the speed fluctuations of the massif on the earth surface when conducting the underground explosions depending on the parameters of large-scale explosions and physical-technical properties of the rock masses in the areas of explosion of the protected object. The formulas for calculating the velocity of rock mass on the earth surface during large-scale explosions in the underground conditions are substantiated and presented. The formulas were used for calculating the vibration velocities of the rock mass on the earth surface in accordance with the parameters of drilling and blasting operations during large-scale explosions in the mines of GK VostGOK. Comparison of theoretical (calculated) data and the results of actual measurements indicates their convergence. By changing the controlled parameters in the calculation formulas, it is possible to quantitatively reduce the seismic effect of a large-scale explosions on the protected objects. Further research will be aimed at studying the influence of tectonic faults, artificial contour crevices, filling massif or mined-out space on the rate of seismic-explosive vibrations during blasting operations in the mines. The research results can be used in the preparation of rules for conducting large-scale explosions at the underground mining.

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