Temat: rock mass - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Determination of the stress-strain state of rock mass and zone of inelastic deformation around underground mine excavation using modern methods of numerical modelling
Autorzy:: Ignatiev, Sergey A.
Sudarikov, Aleksandr E.
Imashev, Askar Zh.
Powiązania:: https://bibliotekanauki.pl/articles/2073903.pdf
Data publikacji:: 2021
Wydawca:: Główny Instytut Górnictwa
Tematy:: rock support
rock mass
surrounding rock mass
geomechanical process
mathematical modelling
zone of inelastic deformation
podpora skalna
górotwór
górotwór otaczający
proces geomechaniczny
modelowanie matematyczne
strefa deformacji niesprężystych
Opis:: The paper reviews methods and trends of numerical modelling of geomechanical processes around underground mine excavations. The most rational method of determining the additional stresses caused by the mine excavations is chosen. Mathematical modelling was performed for excavations of various cross sections and different strength of rocks. The dimensions of the inelastic deformation zone around the mine excavations have been identified. The area of the total fracture zone around the excavation, as well as the area of the roof fracture zone are calculated. The results of the fracture zone modelling are presented both as coordinates and in a graphical form. To simplify application of the modelling results, dependency plots of the obtained parameters were created and analytical dependencies of the fracture zone parameters were identified. The SURFER and KOMPAS software packages were used as the graphic tools to visualize the modelling results.
Źródło:: Journal of Sustainable Mining; 2021, 20, 3; 220--227
2300-1364
2300-3960
Pojawia się w:: Journal of Sustainable Mining
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Geomechanical conditions of causes of high-energy rock mass tremors determined based on the analysis of parameters of focal mechanisms
Autorzy:: Stec, K.
Powiązania:: https://bibliotekanauki.pl/articles/970684.pdf
Data publikacji:: 2015
Wydawca:: Główny Instytut Górnictwa
Tematy:: wstrząs górotworu
naprężenia główne
mechanizm ogniska
rock mass tremor
focal mechanism
principal stresses
Opis:: The aim of the research was to determine the cause of high-energy rock mass tremors (energy E ≥ 105 J) in the area of longwall H-2a located in seam 409/3 in Borynia-Zofiówka-Jastrzębie colliery, basing on the analysis of geological and mining conditions, seismic activity, focal mechanism and local stress field. The research employed the method of seismic moment tensor inversion which provides parameters of focal mechanism (percentage share of its components: isotropic, uniaxial compression or tension, shear component; trend and dip of nodal planes, directions of tension axes and compression stress). The parameters describe processes occurring in focuses of tremors and they are clearly linked with stress conditions in a given area. The conducted tests showed that the cause of occurrence of high-energy tremors and three rockbursts in lot H while mining seam 409/3 with longwall H-2a, was dynamic destruction of roof rocks which could displace towards the cavity created after mining the seam. An additional factor significantly magnifying the process was the share of stresses, which originate from the faults in the area, existing in the rock mass. Results of the research provided additional information to determine the degree of rockburst hazard in the area. Because of very dangerous work conditions (stress parameters reflect the rock mass of high shear strength, where dynamic influence of tremors is stronger) mining activity in longwall H-2a was terminated a few dozen metres earlier than it had been originally planned.
Źródło:: Journal of Sustainable Mining; 2015, 14, 1; 55-65
2300-1364
2300-3960
Pojawia się w:: Journal of Sustainable Mining
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Investigating the effectiveness of a ground support system implemented on Block A: a case study of Southern Africa metalliferous mine
Autorzy:: Manyelo, Kamogelo
Kolapo, Peter
Powiązania:: https://bibliotekanauki.pl/articles/2201373.pdf
Data publikacji:: 2022
Wydawca:: Główny Instytut Górnictwa
Tematy:: support system
joint sets
ground support system
rock mass classification
shaft sinking
wyrobisko korytarzowe
obudowa wyrobiska korytarzowego
klasyfikacja górotworu
głębienie szybu
Opis:: This study aims to investigate the effectiveness of the ground support systems that are planned to be implemented on Block A, which will be excavated through the Marikana fault zone. The block of ground being prepared for mining has been physically affected by the presence of the Marikana fault and is therefore geomechanically and geotechnically weaker than the normal stoping conditions on the rest of the shaft. Joint mapping conducted in Block A raiselines indicated that there is a high concentration of shallow dipping joints which are dipping in opposite directions. Such conditions present special challenges in the planned excavations because they can lead to sudden and uncontrolled collapses unless appropriate action is taken to mitigate such instances. The orientation of joint sets aid the formation of keyblocks, which can collapse provided their weight exceeds the support load bearing capacity or if they are located in between support units. Therefore, stoping in the Marikana fault zone requires a more intensive support with a higher than normal support resistance. The existing ground control strategies, the processes, tools, techniques, and methods that are currently being used for support design were investigated and incorporated into the new system where applicable.
Źródło:: Journal of Sustainable Mining; 2022, 21, 1; 15--26
2300-1364
2300-3960
Pojawia się w:: Journal of Sustainable Mining
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Numerical modelling of destress blasting – a state-of-the-art review
Autorzy:: Miao, Shuting
Konicek, Petr
Pan, Peng-Zhi
Mitri, Hani
Powiązania:: https://bibliotekanauki.pl/articles/2201422.pdf
Data publikacji:: 2022
Wydawca:: Główny Instytut Górnictwa
Tematy:: de-stress blasting
numerical modelling
blasting process
rock mass fracturing
destress blasting design
odprężanie
modelowanie numeryczne
proces strzałowy
szczelinowanie górotworu
projektowanie odprężania
Opis:: As a proactive mine safety measure against the occurrence of rockburst, destress blasting has been applied to numerous mining conditions to precondition highly stressed rock mass to mitigate the risk of rockburst occurrence in deep mines as well as in deep underground constructions. However, the application of destress blasting mostly depends on engineering experience, while its mechanism and efficiency have not been well understood. Rapid advances in computer technology have made numerical simulation an economical and effective method to study the rock blasting effect. Enormous research efforts have been made to numerically investigate the blasting fracture mechanism, optimize blasting design, and assess the efﬁciency of destress blasting. This review focuses on the state-of-the-art progress in numerical modelling associated with destress blasting over the last two decades. Some commonly used modelling approaches for destressing blasting are compared and reviewed. Currently, two different ways of modelling based on static and dynamic modes are typically used to study the effect of blasting. In the static method, destress blasting is simulated by modifying the rock mass’s stiffness and strength properties to obtain the post-blast stress state in the destressed zone. The dynamic modelling technique focuses on the dynamic fracture process of coals and rock masses, during which the predetermination of the damage induced by blasting is not necessary. Moreover, the extent of damage zones around the blast hole can be precisely estimated in the dynamic modelling method by considering time-varying blast pressure and strain rate dependency on the strength of rock mass but at the cost of increased computation and complexity. Besides, different destress blasting modelling methods, generally classified into continuum-based, discrete-based, and coupled methods, are compared and reviewed. The fracture mechanism of blasting in the rock mass is revealed, and the destressing efficiency of the existing destress blasting design is assessed and compared with classical results. The factors that may affect the efficiency of destress blasting are summarized. Finally, the difficulties and challenges associated with the numerical modelling of destress blasting are highlighted briefly.
Źródło:: Journal of Sustainable Mining; 2022, 21, 4; 278--297
2300-1364
2300-3960
Pojawia się w:: Journal of Sustainable Mining
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Determination of the technological parameters of borehole underground coal gasification for thin coal seams
Autorzy:: Falshtynskyi, V.S.
Dychkovskyi, R.O.
Lozynskyi, V.G.
Saik, P.B.
Powiązania:: https://bibliotekanauki.pl/articles/92067.pdf
Data publikacji:: 2013
Wydawca:: Główny Instytut Górnictwa
Tematy:: borehole mining
coal gasification
in situ gasification
rock mass
combustion
chemical balance
górnictwo otworowe
zgazowanie węgla
gazyfikacja in situ
górotwór
spalanie
równowaga chemiczna
Opis:: In this article the characteristics of the criteria of borehole underground coal gasification for thin coal seams are defined. The thermal and material balance calculations for coal seam gasification processes are also explained. The construction, method of in situ gasifier preparation, and the sequence of coal seam gasification for area No 1 (located in the field of Solenovsk coal deposits) are also described. The parameters of borehole underground coal gasification for the Solenovsk coal mine on the model of rock and coal massif are detailed too. The method of in situ gasifier preparation, and the sequence of coal seam gasification during a standard installation are also described in detail. Interpretations based on the conducted research and investigation are also presented.
Źródło:: Journal of Sustainable Mining; 2013, 12, 3; 8-16
2300-1364
2300-3960
Pojawia się w:: Journal of Sustainable Mining
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Quantifying the influence of variations in rock mass properties on stope stability
Autorzy:: Shnorhokian, Shahé
Mitri, Hani
Powiązania:: https://bibliotekanauki.pl/articles/2201418.pdf
Data publikacji:: 2022
Wydawca:: Główny Instytut Górnictwa
Tematy:: stope stability
rock mass variations
numerical modelling
footwall stability
volumetric analysis
brittle shear ratio
stabilność przodka
drgania górotworu
modelowanie numeryczne
stateczność spągu
analiza objętościowa
współczynnik ścinania kruchego
Opis:: Variations in rock mass properties are well-established in rock mechanics and underground mining. The literature is replete with methods of assessing them and determining values that are used in design or numerical analysis. In this paper, a simplified 3D model is constructed for a tabular orebody in the Canadian Shield and instability is quantified using the ”brittle shear ratio” criterion to calculate the volume at risk. A 1-4-7 stope pillar sequence is implemented on four active levels, and three variations in the properties of the host formation are assessed. It is observed that the locations of ore at risk follow the formations of stope pillars and are then transferred to the sill pillars above and below. Instability in the footwall and the hanging wall is observed to be lesser in volume but remains persistent. With the allocation of weak properties to the host rock, at-risk volumes increase in the orebody, footwall, and hanging wall, and the reverse trend occurs with strong greenstone properties. It is concluded that the stress increase in the orebody is due to transfers from the weaker host rock, while that in the greenstone formation is due to the use of a lower compressive strength value.
Źródło:: Journal of Sustainable Mining; 2022, 21, 4; 334--345
2300-1364
2300-3960
Pojawia się w:: Journal of Sustainable Mining
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Mining-induced seismicity of a seam located in rock mass made of thick sandstone layers with very low strength and deformation parameters
Autorzy:: Drzewiecki, J.
Myszkowski, J.
Powiązania:: https://bibliotekanauki.pl/articles/92071.pdf
Data publikacji:: 2018
Wydawca:: Główny Instytut Górnictwa
Tematy:: coal seam exploitation
thick-layered rock mass structure
mining-induced separation of roof layers
large size blocks
seismic activity
eksploatacja pokładów węgla
grubowarstwowa struktura masy skalnej
bryła nadwymiarowa
aktywność sejsmiczna
Opis:: The paper presents the results of calculations and analyses aimed at explaining the cause and mechanism of strong seismic events E≥10⁵ J (local magnitude, M_l≥1.7). Their source are thick and at the same time weak layers of sandstone, theoretically unable to accumulate elastic energy during the exploitation of the seam 209 in hard coal mine Ziemowit in the edge area of seams 206/1, 206/1-2 and 207. In the developed method of forecasting the pressure/stresses in the areas of the rock mass, which are affected by mining exploitation, the formulas linking the results of geophysical measurements of the longitudinal wave anomaly to the pressure values in its impact zone are used. This method was used to locate areas where elevated pressure occurred compared to gravitational pressure, which had a decisive impact on confinement of layers affected by mining exploitation. In such areas the level of confinement/stiffening of the layers is very high, that is why their deformation in the direction of the gobs is limited. In the case of a formation of a large area of gobs, large-size rock blocks are formed in the rock mass, whose mining-induced separation causes their the impact on the ground. Seismic energy accompanying this event is a function of the impact energy reduced by damping resulting from the physiomechanical properties of the cracked substrate.
Źródło:: Journal of Sustainable Mining; 2018, 17, 4; 167-174
2300-1364
2300-3960
Pojawia się w:: Journal of Sustainable Mining
Dostawca treści:: Biblioteka Nauki

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