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Wyświetlanie 1-3 z 3
Tytuł:
Measurement of surface subsidence and ground collapse caused by underground mining in the Boleo Copper District, Mexico
Autorzy:
Kim, Jong-Gwan
Powiązania:
https://bibliotekanauki.pl/articles/1839040.pdf
Data publikacji:
2020
Wydawca:
Główny Instytut Górnictwa
Tematy:
subsidence
vertical movements
copper mine
surface crack
longwall
underground mine
osiadanie
ruchy pionowe
kopalnia miedzi
pęknięcie powierzchniowe
ściana eksploatacyjna
kopalnia podziemna
Opis:
Subsidence and vertical movements in mines are a challenge in mining operations. To qualify as a controlled mine site, ground movements must be measured regularly during mining operations. Boleo Copper District mine was monitored and the movement during mining operations was measured from Oct. 31, 2018 to March 15, 2019. The evaluation of vertical and horizontal movement was determined in four locations in the mine areas M303, M303S, M303 C, and M305. The exploitation area, which measured approximately 80 £ 90 m2 with a height of 2.4 m, impacted the surface in the form of cracks. These cracks were observed on the topographic surveys and varied during the mining operations from the beginning to the end. The final results indicated that the points with the greatest displacement were those in the central zone of the mine excavation (points #3, 5, and 6) and the displacement trend of the ground was toward this zone. In theory, the subsidence is typically lesser than the thickness of the extracted ore. In this case, the maximum subsidence was 1.15 m and the ore seam thickness was 2.4 m. The maximum possible subsidence is typically 55-65% of the extracted seam thickness; however, because chain pillars are generally left in place, and provide some support, this maximum possible subsidence is rarely reached. In this case, the maximum subsidence was 52% of the seam thickness.
Źródło:
Journal of Sustainable Mining; 2020, 19, 2; 126-134
2300-1364
2300-3960
Pojawia się w:
Journal of Sustainable Mining
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Selection mining methods via multiple criteria decision analysis using TOPSIS and modification of the UBC method
Autorzy:
Ali, Mahrous A.M.
Kim, Jong-Gwan
Powiązania:
https://bibliotekanauki.pl/articles/1839056.pdf
Data publikacji:
2021
Wydawca:
Główny Instytut Górnictwa
Tematy:
TOPSIS
UBC method
mining method selection
multiple criteria decision making
metoda UBC
wybór metod wydobycia
wielokryterialne podejmowanie decyzji
Opis:
Mine designers often face difficulties in selecting an appropriate mining method; however, such a method should be selected based on ore and rock characteristics. The selection of mining methods can be considered a type of multi-criteria decision making, and this depends on many factors used in the selection process. The general method used in this field is the University of British Columbia (UBC) method, which determines the criteria of the properties that are compared to determine the best and worst of several mining methods. In this paper we used as new technique which defines as Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). The criteria considered in the UBC method include general shape, ore thickness, ore plunge, and grade distribution, beside the rock quality designation (RQD), and the rock substance strength (RSS). This paper presents an improved TOPSIS method based on experimental design. Additionally, this paper will introduce a modified version of the UBC method that can be employed based on Excel sheet. The best mining methods is cut and fill stoping and top slicing with the same rank equal 0.72, and the second-best mining method is square set stoping with rank equal 0.65.
Źródło:
Journal of Sustainable Mining; 2021, 20, 2; 49-55
2300-1364
2300-3960
Pojawia się w:
Journal of Sustainable Mining
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of an eccentric decoupled charge on rock mass blasting
Autorzy:
Kim, Jung-Gyu
Ali, Mahrous A.M.
Kim, Jong-Gwan
Powiązania:
https://bibliotekanauki.pl/articles/1839045.pdf
Data publikacji:
2020
Wydawca:
Główny Instytut Górnictwa
Tematy:
eccentric decoupled charge
fracture pattern
PFC
AUTODYN
decoupling index
wzór pęknięcia
wskaźnik odsprzęgania
Opis:
Experimental and numerical analyses were conducted to investigate the effect of an eccentric loaded contour hole on a rock mass. In the concrete blocks used for the analyses, detonating cords were placed at the centre of the blast hole and eccentrically against the wall of the blast hole. PFC2D and AUTODYN were used for the numerical analyses, and the results of these software showed that an eccentric decoupled charge can result in the directional development of fractures, thereby enabling the control of cracks in the opposite direction. Even though both types of blasting have identical decoupling indexes, the crack and fracture patterns were affected by the location of the explosive, tamping, and other conditions. The results showed that an eccentric charge holder can be applicable to control the fracture direction and the damaged zone. For an eccentric charge, the initial crack was generated at 0.01 ms and expanded in the intended direction. For the eccentric charge, the maximum pressure at the area in contact with the blast hole wall exceeded that for the central decoupled charge by a factor of 5.5. Furthermore, the pressure in the intended direction was twice of that in the opposite direction.
Źródło:
Journal of Sustainable Mining; 2020, 19, 1; 1-10
2300-1364
2300-3960
Pojawia się w:
Journal of Sustainable Mining
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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