scholarly journals A STUDY ON THE INFLUENCE OF MINING FACE ADVANCE RATE ON THE RISK OF ROCKBURSTS AND DEFORMATION OF A ROCK MASS AND A LAND SURFACE

10.31713/m906 ◽  
2020 ◽  
Author(s):  
Krzysztof Tomiczek ◽  
Keyword(s):  
Rock Mass ◽  
Land Surface ◽  
Face Advance ◽  
Advance Rate ◽  
Mining Face

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.

scholarly journals The impact of drilling and slitting construction on damage field: evolution characteristics in low-permeability coal seam

2021 ◽  
Vol 37 ◽  
pp. 205-215
Author(s):  
Heng Chen ◽  
Hongmei Cheng ◽  
Aibin Xu ◽  
Yi Xue ◽  
Weihong Peng
Keyword(s):  
Finite Element ◽  
Rock Mass ◽  
Damage Mechanics ◽  
Effective Strain ◽  
Secondary Development ◽  
Distribution Area ◽  
Finite Element Program ◽  
Element Program ◽  
Mining Face ◽  
The Impact

ABSTRACT The fracture field of coal and rock mass is the main channel for gas migration and accumulation. Exploring the evolution law of fracture field of coal and rock mass under the condition of drilling and slitting construction has important theoretical significance for guiding efficient gas drainage. The generation and evolution process of coal and rock fissures is also the development and accumulation process of its damage. Therefore, based on damage mechanics and finite element theory, the mathematical model is established. The damage variable of coal mass is defined by effective strain, the elastoplastic damage constitutive equation is established and the secondary development of finite element program is completed by FORTRAN language. Using this program, the numerical simulation of drilling and slitting construction of the 15-14120 mining face of Pingdingshan No. 8 Mine is carried out, and the effects of different single borehole diameters, different kerf widths and different kerf heights on the distribution area of surrounding coal fracture field and the degree of damage are studied quantitatively. These provide a theoretical basis for the reasonable determination of the slitting and drilling arrangement parameters at the engineering site.

scholarly journals Two-Dimensional Modeling of the Influence of Underground Mining Direction on Slope Stability in Coordinated Open-Pit and Underground Mining

2021 ◽  
Author(s):  
Bowen Liu ◽  
Zhenwei Wang ◽  
Xinpin Ding ◽  
Zhitao Wang ◽  
Bin Li
Keyword(s):  
Rock Mass ◽  
Slope Stability ◽  
Underground Mining ◽  
Mining Area ◽  
Two Dimensions ◽  
Open Pit ◽  
Engineering Practice ◽  
Inverse Slope ◽  
Coal Wall ◽  
Mining Face

Abstract Under a background of coordinated open-pit and underground mining engineering practice in the Pingshuo mining area, a combination of numerical simulations and similar-model experiments was used to study the influence of the underground mining direction on slope deformation in two dimensions. The results show that the disturbance caused by inverse-slope mining is more obvious than that caused by along-slope mining. Underground mining presents an asymmetric influence on the open-pit slope; the slope rock mass on the open-off cut side is disturbed more than that on the coal-wall side. Compared with the slope in front of the advancing direction of the underground mining face, the degree of rock-mass damage and stress concentration of the slope of the open-off cut side are more serious. As such, in coordinated open-pit and underground mining practice, an along-slope mining direction is recommended to reduce adverse effects on slope stability and improve the recovery rate of coal resources.

scholarly journals Improving the efficiency of tunneling underground mine workings with the use of blasthole charges with Munroe effect

2020 ◽  
pp. 15-23
Author(s):  
Farkhodbek Umarov ◽  
◽  
Utkir Nasirov ◽  
Gafur Nutfulloev ◽  
Zoir Nazarov ◽  
...  
Keyword(s):  
Rock Mass ◽  
Explosive Charge ◽  
Underground Mine ◽  
Theoretical Research ◽  
Hydrodynamic Theory ◽  
Energy Concentration ◽  
Face Advance ◽  
Efficiency Ratio ◽  
Underground Mine Workings ◽  
Mine Workings

Introduction. Various techniques of breaking rock by explosion have currently been developed when tunneling underground mine workings, but asymmetrically directed stress fields application is of the main interest. Research aim is to study explosion energy distribution and maximum concentration deep down the blasted rock mass. Blast energy concentration may be achieved by using the principle of cumulation in the hole back by means of changing the design of the blasthole explosive charge. Methodology. Based on the analyzed literature and theoretical research it is recommended to use the design of a blasthole explosive charge with the use of Munroe effect, which makes it possible to increase the blasthole efficiency ratio (BER), reduce drilling activity, reach sharper design contours of mine workings and eliminate bootlegs. The action of blasthole explosive charges with Munroe effect has been theoretically investigated, hydrodynamic theory of cumulation has been studied, and the dependences have been determined between the liner’s collapsing angle alternation and the radius of the cone, its height, initial velocity, and cumulative jet velocity. Results. The main factors which determine the efficiency of the proposed new technique of blasting against the basic technique are the blasthole efficiency ratio, face advance pace after one blast, the amount of rock mass detached after one blast, and the granulometric composition of the blasted rock mass. Summary. The developed design of the blasthole explosive charge with Munroe effect makes it possible to increase BER, face advance per one cycle, and increase the amount of the broken rock mass.

scholarly journals Simulation of Time-dependent Deformation of Visco-elastic Rock Mass around Mine Tunnel being induced by Face Advance.

1994 ◽  
Vol 110 (14) ◽  
pp. 1082-1088
Author(s):  
Yoshihiro OGATA ◽  
Tsutomu YAMAGUCHI ◽  
Michio KURIYAGAWA ◽  
Seisuke OKUBO ◽  
Yuichi NISHIMATSU
Keyword(s):  
Rock Mass ◽  
Time Dependent ◽  
Face Advance ◽  
Elastic Rock

An Analysis Of The Interaction During Simultaneous Use Of Copper Ore And Salt Deposits In The LGOM Mines With Regard To Displacement And Deformation Of Rock Mass

2015 ◽  
Vol 60 (2) ◽  
pp. 535-548
Author(s):  
Edward Popiołek ◽  
Zdzisław Kłeczek ◽  
Zygmunt Niedojadło ◽  
Ryszard Hejmanowski ◽  
Wojciech Skobliński ◽  
...  
Keyword(s):  
Rock Mass ◽  
Land Surface ◽  
Mineral Resources ◽  
Theoretical Models ◽  
Mining District ◽  
Copper Ore ◽  
Rock Mass Deformation ◽  
Mining Works ◽  
Mining Tremors ◽  
The Impact

Abstract Excavation of the two bedded deposits of mineral resources in a small vertical distance may cause additional increased mining risks (rock mass deformation, rock bursts and mining tremors, threat to land surface). This paper considers the impact of excavation of the copper ore deposit on the bed of rock salt located above it and the opposite, in terms of displacements and deformations. We used the theoretical models of processes verified by previous in situ observations in the mines of the Legnica-Głogów Copper Mining District. We analysed the potential for reducing the risks, among others, through coordination of mining works.

scholarly journals The influence of the fault zone width on land surface vibrations after the high-energy tremor in the “Rydułtowy-Anna” hard coal mine

2018 ◽  
Vol 36 ◽  
pp. 02007 ◽  
Author(s):  
Elżbieta Pilecka ◽  
Dariusz Szwarkowski
Keyword(s):  
Rock Mass ◽  
Fault Zone ◽  
Seismic Wave ◽  
Coal Mine ◽  
Land Surface ◽  
High Energy ◽  
Hard Coal ◽  
Surface Vibrations ◽  
The Impact ◽  
Damage Risk

In the article, a numerical analysis of the impact of the width of the fault zone on land surface tremors on the area of the “Rydułtowy – Anna” hard coal mine was performed. The analysis covered the dynamic impact of the actual seismic wave after the high-energy tremor of 7 June 2013. Vibrations on the land surface are a measure of the mining damage risk. It is particularly the horizontal components of land vibrations that are dangerous to buildings which is reflected in the Mining Scales of Intensity (GSI) of vibrations. The run of a seismic wave in the rock mass from the hypocenter to the area’s surface depends on the lithology of the area and the presence of fault zones. The rock mass network cut by faults of various widths influences the amplitude of tremor reaching the area’s surface. The analysis of the impact of the width of the fault zone was done for three alternatives.

scholarly journals Land Surface Subsidence Due to Mining-Induced Tremors in the Upper Silesian Coal Basin (Poland)—Case Study

2020 ◽  
Vol 12 (23) ◽  
pp. 3923
Author(s):  
Paweł Sopata ◽  
Tomasz Stoch ◽  
Artur Wójcik ◽  
Dawid Mrocheń
Keyword(s):  
Rock Mass ◽  
Land Surface ◽  
Continuous Monitoring ◽  
Geological Structure ◽  
Vertical Surface ◽  
Coal Basin ◽  
Surface Displacements ◽  
Upper Silesian Coal Basin ◽  
Mining Tremors

Seismic phenomena threaten land-based buildings, structures, and infrastructure and can transform land topography. There are two basic types of seismic phenomena, namely, tectonic and anthropogenic, which differ mainly in epicenter depth, surface impact range, and magnitude (energy). This article shows how a land surface was changed by a series of seven rock mass tremors of magnitude ML = 2.3–2.6 in March–May 2017. Their immediate cause was the “momentary” acceleration of void clamping, which was activated by local and short-term seismic phenomena caused by human activity. The induced seismic events resulted from the geological structure of the rock mass, which in the specific region of examination was classified as being highly prone to mining tremors. The authors focused on describing vertical surface displacements in the Upper Silesian Coal Basin in the south of Poland. The surface deformations were identified using DInSAR technology, which allows quasi-continuous monitoring of large areas of land surface. The present research used freely available data from the Copernicus Program and seismic data from the European Plate Observing System.

scholarly journals A Study of the Effects of Geological Conditions on Korean Tunnel Construction Time Using the Updated NTNU Drill and Blast Prediction Model

2021 ◽  
Vol 11 (21) ◽  
pp. 10096
Author(s):  
Yangkyun Kim ◽  
Sean Seungwon Lee
Keyword(s):  
Rock Mass ◽  
Prediction Model ◽  
Rock Properties ◽  
Design Stage ◽  
Construction Time ◽  
Tunnel Support ◽  
Advance Rate ◽  
Rock Mass Quality ◽  
Geological Conditions ◽  
Drill And Blast

This paper analyses the construction time and advance rate of a 3 km long drill and blast tunnel under various geological conditions using an upgraded NTNU drill and blast prediction model. The analysis was carried out for the five types of Korean tunnel supports according to the rock mass quality (from Type 1, meaning a very good rock mass quality; to Type 5, meaning a very poor rock mass quality). Four kinds of rock properties, as well as the rock mass quality, for each tunnel support type were applied to simulate different geological conditions based on previous studies and the NTNU model. The construction time was classified into five categories: basic, standard, gross, tunnel and total, according to the operation characteristics to more effectively analyse the time. In addition, to consider the actual geological conditions in tunnelling, the construction times for the three mixed geological cases were analysed. It was found that total construction time of a tunnel covering all the operations and site preparations with a very poor rock mass quality was more than twice that of a tunnel with a very good rock mass quality for the same tunnel length. It is thought that this study can be a useful approach to estimating the construction time and advance rate in the planning or design stage of a drill and blast tunnel.

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