Back filling

Question 1

what is back filling

Answer 1

material used to fill the cavities created by mining so as to establish and retain safe working conditions economically

Question 2

dry fill

Answer 2

sand, gravel, waste, rock

Question 3

cemented

Answer 3

water rock mixed with cement

Question 4

hydraulic

Answer 4

mill tailing

Question 5

decline vs ore

Answer 5

effective ore transportation depends on fragmentation (haulage does not require crushing if the fragmentation from blasting is reasonable)
mine served by decline doesn’t require an undergound crush

Question 6

ground control

Answer 6

• depends on rock defect types: joing, vein, fault, fault zone

Question 7

RQD

Answer 7

rock quality design

Question 8

RMR

Answer 8

rock mass classification

Question 9

failure modes

Answer 9

circular, wedge, plane, toppling

Question 10

factor of safety

Answer 10

forces holding it up/forces aching for it to fail

Question 11

shotcrete

Answer 11

concrete that is applied by spraying

Question 12

fibrecrete

Answer 12

shotcrete containing small steel polymer or plastic fibres for reinforcement

Question 13

ventilation

Answer 13

primary: gets enough air underground
secondary: gets air to where it is needed