A mine is planned to use a decline with a dip of 30° to access the ore body at a depthof 500 meters. Estimate the vertical and horizontal insitu stresses at 500 m depth,assuming the average unit weight of rock 27kNm3, horizontal Young's modulus 75GPa …
2) Combined Stress: A condition of stress that cannot be represented by a single resultant stress. 2.1) Shear stress: Forces parallel to the area resisting the force cause shearing stress. It differs to tensile and …
in mines in the Carletonville area of the Witwatersrand Basin. The surface temperature data and heat flow data, together with an extensive thermal conductivity database, make it possible to predict VRTs in new platinum mining areas as well as chromium and vanadium mines if such mining proceeds to substantial depths.
The method is based on the use of the intact rock mass stiffness matrix formed prior to mining. Modeling of drivage using the method of initial stresses allows splitting the problem into two subproblems: the first subproblem is on mechanical state of rock mass during roof and wall rocks displacement, the second subproblem describes joint ...
High horizontal stresses and high horizontal to vertical in-situ principal stress ratios in the plane of underground drifts and entries can damage weakly laminated roof rocks quite severely. Such stresses are difficult to measure accurately, as illustrated by case histories of in-situ stress measurement at Wistow and Lea Hall mines, in the UK. Their direction and relative magnitude …
kinds of mines over a very extended period of time. Underground forces in mines can be repelled in two ways, either by pillars or artificial support for which timber is the most widely used. Leonard Obert 1/ has done 1/ Obert, Leonard, Measurement of pressures on rock pillars in underground mines: Part I, U. S. Bureau of Mines
The stress state at a point in a rock mass is generally presented in terms of the magnitude and orientation of the principal stresses (remember that the stress state is completely described …
ABSTRACT: This paper presents several new methods to help interpretation and understanding of ground stress. The methods are based on data from 239 stress measurements conducted …
Erosion – if horizontal stresses become 'locked in', then the erosion/removal of overburden (i.e. decrease in V) will result in an increase in K ratio ( H/ V). Tectonics – different forms of tectonic activity (e.g. subduction zones), can produce high horizontal stresses.
EFFECT OF IN-SITU STRESSES ON THE STABILITY OF COAL MINE DEVELOPMENT WORKINGS by Murali Mohan Gadde . Among the different types of ground control problems associated with underground coal mining, those related to in-situ stresses are the most common ones affecting the safety of a mining operation.
Canadian crustal stresses and their application in mine design Author ARJANG, B 1 [1] Natural Resources Canada, CANMET, Mining and Mineral Sector, Ottawa, Ont., Canada Conference title Mine Planning and Equipment Selection 1998 Conference name MPES : International Symposium on Mine Planning and Equipment Selection (7 ; Calgary ) ...
Arjang, B., & Herget, G. (1997). In situ ground stresses in the Canadian hardrock mines: An update. International Journal of Rock Mechanics and Mining Sciences, 34(3 ...
The sites were situated in both igneous and sedimentary rocks ranging in age from 3 000 to 250 m.y. and cover a depth range from 20 to 2 500 m.At shallow depths, horizontal stresses tend to be ...
Calculation of the limiting stresses in rocks around isolated mine workings and in pillars Fisenko, G. L. Abstract. Publication: Journal of Mining Science. Pub Date: November 1972 DOI: 10.1007/BF02497578 Bibcode: 1972JMinS...8..601F Keywords: Slip Surface; Logarithmic Spiral; Weak Contact; ...
section of Maple Meadows mine) covering a distance of about 18 miles (figure 3). Five of the low strain sites are in a separate but adjacent geographic area to the high strain zone stretching across two mines (southwest section of Maple Meadows Mine and Beckley No. 1 Mine) for a distance of about 6 miles. Therefore,
ABSTRACT:. Estimating in-situ stresses is an important step in the analysis and design of any underground rock excavation. The cost and time restrictions associated with each measurement has prevented the extensive use of the established stress measurement techniques. To evaluate the potential of Kaiser Effect as a reliable and economical stress …
the use of seismic tomography to map stress in an underground mine by comparing pressure changes (induced pressure) in a pillar to velocity changes in settings where geologic features, …
1. Heat Stress Hazards. Heat stress severely threatens miner health and safety, especially in hot and humid areas. With the physically demanding nature of mining jobs and the weight of their protective gear, miners are more likely to …
2. Rock Stresses Insitu () Stresses Induced Stresses Exist in the rock prior to any Occurs after artificial disturbance e.g. disturbance. Mining, Excavation, pumping, Injection, Energy extraction, applied load, swelling etc. Tectonic Stresses Residual Stresses Gravitational Terresterial Stresses •Diagenesis Stresses •Seasonal tpr. variation •Metasomatism (Flat …
maximum lateral stresses and their directions in NSW and Queensland coalfields. These findings can provide a valuable benchmark for mine planning and strata control with potential savings in mine operating costs. INTRODUCTION To date, SCT has conducted some 430 successful underground stress measurements in Australian and overseas mines.
This SLR aimed to identify the research gap in the area of heat stress effect on underground miners and its control. An extensive literature search was carried out on …
This International Mine Action Standard (IMAS) provides specifications and guidance to National Mine Action Authorities (NMAAs) and mine action organisations on the minimum …
The purpose of this study is to determine the distribution of stresses in a particular portion of the ore body of an operating mine. DESCRIPTION OF GEOLOGY The ore body of this base metal mine is a lenticular mass of copper-zinc-iron sulfides, enclosed in a drag-folded quartz mica schist. The schistose host rock has steep dip which varies from north to south and an east …
Aguinaga, Microbial community shifts in response to acid mine drainage pollution within a natural wetland ecosystem, Front. Microbiol., № 9, с. 1445
To illustrate the basic mechanics of plastic flow and the nature of sliding contact conditions in plane-strain cutting and wedge indentation, experiments were conducted where the metal specimen was observed in situ as it is machined or indented. Figs. 1 (a) and (b) show the schematic representations of the cutting and wedge indentation configurations, respectively.
ABSTRACT. ABSTRACT A large number of recent mine slope failures indicate the inadequacy of the methods currently being used in their stability analyses. One major shortcoming of the conventional approach is its inability to take account of the appropriate excavation sequence. This results in unconservative slope angles for cut-down embankments. This paper …
Canadian hard rock mining industries have long recognized the significance of high horizontal stresses as a factor affecting the stability of roof and rib conditions in underground mines. Recently, a growing segment of the U.S. underground stone mining industry has also begun to recognize that horizontal
DOI link for Stresses in an underground metal mine. Stresses in an underground metal mine. By P.Ramírez Oyanguren, J.A.Ojeda Ruiz, R.Lain Huerta. Book Modelling of Mine Structures. Click here to navigate to parent product. Edition 1st Edition. First Published 1988. Imprint Routledge. Pages 6. eBook ISBN 9780203746813.
Download Citation | On Feb 12, 2021, P.Ramírez Oyanguren and others published Stresses in an underground metal mine | Find, read and cite all the research you need on ResearchGate
Stresses are a fundamental part of stability analysis in mine design, but little effort has been put into understanding stresses in mines compared to methods of estimating rock mass strength. Most mines are located in regions of …
An overcoring stress measurement in a mine at a depth of 1.5 km gives normal stresses of 62 mpa in the n–s direction, 48 mpa in the e–w direction, and 51 mpa in the ne–sw direction. determine the magnitudes and directions of the principal stresses.
The topicality of this work is due to the importance of developing such a new-generation monitoring computer-aided measurement system intended for ensuring the safety of mining works and coal mining that would allow one to monitor all required parameters and defects in a massif. Additional optic-fiber losses have been investigated with the aim to …
Rock at depth is subjected to stresses resulting from the weight of the overlying strata and from locked in stresses of tectonic origin. When an opening is excavated in this rock, the stress …
An analytical modelling of the rotation of in-situ principal stresses orientation in the vicinity of an underground opening. Haiyan Liu a School of Mechanics and Civil Engineering, China ... (Beijing), Beijing, China;c International Innovation Center for Mining Rock Mechanics, China University of Mining and Technology (Beijing), Beijing, China ...
A GUIDE TO ROUTINE SEISMIC MONITORING IN MINES by A J Mendecki, G van Aswegen and P Mountfort ISS International Limited P.O. Box 12063, Die Boord, 7613, RSA ... Figure 1 Apparent stresses of selected seismic events with equal local magnitudes m . 1.0 in a South African Gold Mine. The ratio of the highest to the lowest apparent
To date, SCT has conducted some 430 successful underground stress measurements in Australian and overseas mines. From these, 349 measurements were conducted in Australian …