Search

Start Over Subject doly Original context has metadata only false

12. Geomechanical effects of operation and closing the Idrija Mercury Mine on the environment

Creator:
Likar, Jakob
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, doly, mines, Mercury Mine, cross-stope mining method, backfilling, sublevel mining method with consolidated backfill, low bearing capacity rock structure, geotechnical measurement, 7, and 551
Language:
English
Description:
The past five centuries of the Idrija Mercury Mine’s operation have had consequences on the environment, which have directly influenced the deformations developing in the wider exploration area. During the many years of mercury ore exploitation, the cross-stope mining method with backfilling from bottom to top was used. This has strongly transformed the stress-strain field in the surrounding rocks and caused long-term deformation processes that are still in progress. This is because the deformations have a small time gradient and thus bigger breaks or faster sliding terrain above old mine workings are not expected. The surface movements are bigger in the area built of Permian-Carboniferous, low-bearing-capacity rocks, which in the past was destroyed by major tectonic movements in the rock structure. Mine closure works, which included grouting and hardening of destroyed underground areas, as well as filling parts of the mine and backfilling empty spaces (i.e., mine roadways, blind shafts), are finished. The efficiency of mine shutdown works is constantly being verified by means of geotechnical and other measurements and observations, and will continue in the future., Jakob Likar., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

13. Influence of dislocations on bumps occurrence in deep mines

Creator:
Petr Procházka, Jiřina Trčková, and Lok, Tat Seng
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, numerické modelování, doly, numerical modeling, mines, free hexagon method, deep mines, bumps occurrence, 7, and 551
Language:
English
Description:
The problem of bumps occurrence in deep mines during the long wall mining appears to be one of the most serious one in the design of engineering of mining. The bumps are caused for various reasons, but basically it is an aftermath of the accumulated energy, which is released under some unfavorable conditions. In this paper the influence of given dislocations and their slope in a coal seam are studied based. The numerical tool is the free hexagon method. This method belongs to a set of discrete element methods and enables us to define and calculate stresses in a natural way along the interfacial boundaries of adjacent particles (elements). Since the bumps are affected by a possible slip along the dislocations, dynamical response has to be taken into account. The velocity of excavation of the mine is considered by successive change of values of Eshelby’s forces on the face of the wall., Petr Pavel Procházka, Jiřina Trčková and Tat Seng Lok., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

15. Monitoring and documentation of flaking-off phenomena in the historical Jeroným Mine

Creator:
Radovan Kukutsch, Petr Žůrek, and Martin Stolárik
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, doly, jeskyně, mines, caves, caved areas, visual monitoring, Jeroným Mine, flaking-off, 7, and 551
Language:
English
Description:
The medieval Jeroným Mine is a mine working in which places of various degrees of rock mass disintegration are there. Time-lapse recording, which has been performed in the Jeroným Mine since the year 2009, was induced by a necessity of documenting both areas of flaking-off and caved areas owing to an increased rate of occurrence of flaking-off phenomena in mine workings - rooms K3 and K4 of this mine. The methodology of recording, which uses as a basis repeated recording in time in the framework of geotechnical measurements carried out quarterly, is based on the principle of maintenance of not only parameters of images themselves, but also of location of a photo device used for documentation provision. This process is followed by the creation of information sheets of areas of flaking-off and caved areas and their classification. The method of recording was used owing to a high degree of disintegration of the rock mass in selected mine workings, a possibility of extension of caved areas and also the high rate of occurrence of subsidence phenomena occurring above those workings and even sporadically reaching the mine workings. Time-lapse recording is thus performed primarily in mine workings with reduced stability, situated very close to the surface. With regard to the principle of this method, results will be known only in further years., Radovan Kukutsch, Petr Žůrek and Martin Stolárik., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

18. Numerical modelling of rock mass deformation in sublevel caving mining system

Creator:
Blachowski, Jan and Ellefmo, Steinar
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, numerické modelování, doly, numerical modeling, mines, rock mass deformation, sub-level caving, monitoring, Kvannevann mine, 7, and 551
Language:
English
Description:
Combination of numerical models of deformations and repeated geodetic measurement results provide reliable information on the state of the rock mass in a mining area and support planning and control of the mining operation. The paper describes the concept of integrated monitoring and analysis of rock mass deformation in the Kvannevann iron ore mine (Norway) using sub-level caving (SLC) method. Geodetic control network developed for periodic measurements of surface subsidence and a source of geometrical data for numerical modelling of deformations using finite element method (FEM) has been characterised. Focus is given to the results of initial numeric al analyses with FEM of rock mass deformations due to SLC mining. The results of the modelling provided information on possible extent of deformation zones on the mining ground surface once mining with new method commences., Jan Blachowski and Steinar Ellefmo., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

19. Permeability and volumetric changes in coal under different test environment

Creator:
Aziz, Naj, Ren, Ting, Nemcik, Jan, and Zhang, Lei
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, těžba uhlí, doly, coal mining, mines, coal mine gas, coal permeability, volumetric changes, 7, and 551
Language:
English
Description:
Permeability refers to the ability of coal to transmit gas when a pressure or concentration gradient exists across it. The permeability of coal is dependent upon factors that include effective stress, gas pressure, water content, disturbance associated with drilling and matrix swelling/shrinkage due to adsorption/desorption. A programme of laboratory tests were conducted on coal samples from the Bulli seam for evaluating the permeability and drainability of coal. Two different types of permeability apparatus were used in this study. The methods of permeability testing of coal under different triaxial conditions are discussed. Permeability testing of the Bulli seam coal with N2 is described. The laboratory test results were found to be in agreement with the calculated permeability values, Naj Aziz, Ting Ren, Jan Nemcik and Lei Zhang., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public