Rational shape of the cross section of an underground mine working

1992 ◽  
Vol 28 (2) ◽  
pp. 156-159
Author(s):  
V. K. Tsvetkov ◽  
V. D. Prikhod′ko
Keyword(s):  
Cross Section ◽  
Mine Working ◽  
Underground Mine ◽  
Underground Mine Working ◽  
The Cross ◽  
Rational Shape

scholarly journals INFLUENCE OF UNDERGROUND MINE PARAMETERS ON THE VALUE OF DAYLIGHT SURFACE SETTLEMENT OF UNDERMINED TERRITORY

2020 ◽  
Vol 11 (2) ◽  
pp. 5-18
Author(s):  
O. A Bogomolova ◽  
A. V Zhidelev
Keyword(s):  
Elastic Modulus ◽  
Cross Section ◽  
Lateral Pressure ◽  
Pressure Coefficient ◽  
Underground Mine ◽  
Cross Sectional ◽  
Lateral Pressure Coefficient ◽  
Vertical Displacements ◽  
The Cross ◽  
Sectional Shape

The article presents the analysis results of influence of shape and dimensions of cross-section, laying depth of mine, cross-section shape and dimensions of underground mine on the daylight surface settlement of undermined territory depending on the different numerical values of the soil lateral pressure coefficient of the surrounding soil. The numerical solution was obtained in an elastic setting using the computer programs «FEA» and «Stability». In the calculations, the elastic modulus of the enclosing rocks is taken equal to the dimensionless constant E /γ H = 500 (where γ; H are the rocks volumetric weight and laying depth of mine), therefore, the numerical values of the vertical displacements gained as a result of the calculations are also dimensionless. This approach is convenient for both quantitative and qualitative analysis, because not only specific values of vertical displacements are considered, but also change patterns of their values depending on changes in the numerical values of the variables of the calculated parameters. Assuming that the displacements in the linear formulation of the problem are inversely proportional to the elastic modulus, their magnitudes can be determined for any other value of E . It was established the vertical displacements of earth’s surface points located above the mine, provided that the depth of its laying is more than 15.2 m and the dimensions of the cross section are greater than 4×4 m, significantly depend on the shape of the cross section and the lateral pressure coefficient of the surrounding rock. In addition, smaller vertical precipitation of the daylight surface corresponds to an underground mine having an exotic and «non-technological» cross section in the deltoid form. Therefore, the problem arises is to obtain such an optimal cross-sectional shape of the mine that would ensure the minimum precipitation of the earth's surface. The cross-sectional shape of the mine must be as “technological" as possible according to its advancement. The subject of further research is the solution of these problems.

APPLICATION OF OTT'S MINE COORDINATE SYSTEM IN THE PAST AND IN PRESENT DAY

2013 ◽  
Vol 39 (2) ◽  
pp. 53-58 ◽  
Author(s):  
Hana Staňková ◽  
Pavel Černota
Keyword(s):  
Coordinate System ◽  
Coal Mining ◽  
Mine Working ◽  
Underground Mine ◽  
The State ◽  
The Past ◽  
Underground Mine Working

The coal district system of coordinates for mines located in the Ostrava region was established in 1858 by Dipl. Ing. František Ott, Surveyor of the Emperor Ferdinand Northern Railway (Severní dráha Ferdinandova). Coordinates of all significant points of existing mine shafts, characteristic mine surface points, and points in terrain, were determined by establishing mine triangulation within the Western part of the Ostrava-Karviná Coal District (OKR) on an area comprising almost 58 km2. Said points were stabilized by granite stones. The reason to establish this system of coordinates was to determine the points of a uniform basis of coordinates for making surveys both on the mine surface, i.e. for connecting the underground mine working, and simultaneously for removing any discrepancies occurring with respect to mine boundaries among particular proprietors, i.e. to allow for exact demarcation of mine areas bestowed to them by the state. Thus, nowadays Ott's system of coordinates that used to be applied during the period, in which within the OKR redevelopment works took place, like abatement the coal mining consequences.

scholarly journals Optimization of Parameters to Improve Ventilationin Underground Mine Working using CFD

2019 ◽  
Vol 8 (4) ◽  
pp. 12436-12441
Keyword(s):  
Mine Working ◽  
Underground Mine ◽  
Optimization Of Parameters ◽  
Underground Mine Working

Intundergroundtmine,tittistverytimportantttotmainta intfreshtandtsufficienttairtintunventilatedareasttotmaintainsafew orkingenvironmenttfortworkers.tTotstudytthetbehaviourtoftairflo wintundergroundtmine,tatT shaped crosscuttregiontoftBordandt Pillarmining ist considered forsimulation tint twot differentcases:twithouttandtwithtthintbratticetpositioningtattcross cutregion.tBratticetistcostteffectiveventilationcontroltdevicettodefl ectairtintotunventilatedareasintundergroundmine.Theultimatetob jectiveisttotfindtthetbestlocationtanddimensionofbratticetacrosstt hetcrosscuttregiontbytwhichtonetcantgetmaximumtvelocitytattdea dtend.tInthistthesis,tatcomputationalfluiddynamicst(CFD)tandtop timizationtalgorithmstareconsideredfortmaximizingtthetairtflowta ttthetdeadtendtbyplacingtatbratticetattoptimumlocation.tTwodiffe rentoptimizationtalgorithms:tmultiobjectivetgenetictalgorithm(MOGA)andtnonlinearprogrammingtofquadraticLagrangian(NLPQL)toptimizatio nttechniquestweretusedtintthisstudy.ANSYStFLUENTtsoftwareti stusedtforCFDtmodelingtat Tshapedtcrosscuttregiontandcomputestthetsimulationtresulttofairtf lowtvelocitytattdeadtend.tOptimizationttechniquesareusedforttoop timizetfourtinputtparameters;tbratticetpositiontverticalandhorizo ntaltfromtthewalltoftcrosscuttregiontandtwidthtandlengthtoftbratt ice.Thetobjectivestfortoptimizationstaretomaximizetthetvelocitytat tdeadtendtandtminimizetthetpressuredroptintcrosscuttregion.Com parisonistcarriedtouttbetweencrosscuttregiontwithouttandtwithtat thinbratticetusingoptimizationttechniquestandtfoundtthetbesttlocationtanddimensionoftbra ttice.tTotincreasethetairtflowtvelocitytattdeadtendincrease tthetsafetworkingtfortworkerstandtsupplyadequateairtatworkingtf ace

A New Approach to the Demonstration of Oxidase-Localization Using Tannic Acid Or Catechin

1973 ◽  
Vol 31 ◽  
pp. 698-699
Author(s):  
V. Mizuhira ◽  
Y. Futaesaku
Keyword(s):  
Cross Section ◽  
Tannic Acid ◽  
Elastic Fiber ◽  
The Other ◽  
New Approach ◽  
Tissue Block ◽  
Active Reaction ◽  
The Cross

Previously we reported that tannic acid is a very effective fixative for proteins including polypeptides. Especially, in the cross section of microtubules, thirteen submits in A-tubule and eleven in B-tubule could be observed very clearly. An elastic fiber could be demonstrated very clearly, as an electron opaque, homogeneous fiber. However, tannic acid did not penetrate into the deep portion of the tissue-block. So we tried Catechin. This shows almost the same chemical natures as that of proteins, as tannic acid. Moreover, we thought that catechin should have two active-reaction sites, one is phenol,and the other is catechole. Catechole site should react with osmium, to make Os- black. Phenol-site should react with peroxidase existing perhydroxide.

Energy Distribution in Electron Beams

1972 ◽  
Vol 30 ◽  
pp. 568-569
Author(s):  
Tamotsu Ohno
Keyword(s):  
Electron Beam ◽  
Energy Distribution ◽  
Cross Section ◽  
Integral Curve ◽  
Electron Beams ◽  
Electron Gun ◽  
Angular Divergence ◽  
Apparent Increase ◽  
Integral Width ◽  
The Cross

The energy distribution in an electron; beam from an electron gun provided with a biased Wehnelt cylinder was measured by a retarding potential analyser. All the measurements were carried out with a beam of small angular divergence (<3xl0-4 rad) to eliminate the apparent increase of energy width as pointed out by Ichinokawa.The cross section of the beam from a gun with a tungsten hairpin cathode varies as shown in Fig.1a with the bias voltage Vg. The central part of the beam was analysed. An example of the integral curve as well as the energy spectrum is shown in Fig.2. The integral width of the spectrum ΔEi varies with Vg as shown in Fig.1b The width ΔEi is smaller than the Maxwellian width near the cut-off. As |Vg| is decreased, ΔEi increases beyond the Maxwellian width, reaches a maximum and then decreases. Note that the cross section of the beam enlarges with decreasing |Vg|.

Research in the cross-section of community psychology and global climate change: A call for action

2009 ◽  
Author(s):  
Marci Culley ◽  
Holly Angelique ◽  
Courte Voorhees ◽  
Brian John Bishop ◽  
Peta Louise Dzidic ◽  
...  
Keyword(s):  
Climate Change ◽  
Cross Section ◽  
Global Climate Change ◽  
Community Psychology ◽  
Global Climate ◽  
The Cross
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