Drilling

Question 1

rock breakage

Answer 1

method to use for rock excavation are mechanical rock cutting tools or explosive charges

Question 2

Percussive drilling: Top hammer

Answer 2

> produces, small holes
impact and rotation of the bit used to fracture the rock is transmitted from the drill
limited achievable depth

Question 3

Percussive drilling: Down the hole

Answer 3

> produces larger hole sizes
hammer is located at the bottom of the drilling string
larger and deeper holes

Question 4

Rotary drilling

Answer 4

> drag bits (soft rock)
tricone bits (med-hard rock)
larger roller bit

Question 5

jet piercing

Answer 5

used to drill blastholes in hard, abrasive rock

Question 6

percussive dirlling: UG

Answer 6

handled jackleg: drill small holes

Jumbo drill rig: single or multiple booms depending on the opening dimensions nad rock mass properties

Question 7

surface mining: tunneling and boring machines

Answer 7

used to drive circular tunnels
> rock types - weak to very strong abrasive
> debris collected and removed by conveyor belts

raise borer
> used to produce circular excavation either between diff level