1. WEL COME

2. DRILLING AND BLASTING

3. Index
 Introduction of Drilling and its Necessity
 Terminology use for drilling
 Selection of drilling method
 Selection of drilling equipments
 Introduction of Blasting
 Method of blasting
 Terms used for blasting
 Explosive used for blasting
 Precaution in blasting

4. Introduction
• Drilling :
Before rock is excavated,
it is Necessary to loosen
it.In the case of hard rocks
this loosening is done by
drilling the holes, filling
these with explosives and
discharging the
explosives.

5. Necessity of Drilling
• Cracking of rocks are requirement for construction
of Dam.
• Take out the tones from the cory.
• To obtain samples of soil for test.
• To provide wells for supplies of water or for deep
drainage.
• To locate and evaluate deposites of minerals.

6. Terminology use for Drilling
• Bits :
The part which
directly engages the
rock for its
disintegration is known
as the ‘drill bit’.
They can be sharpened
as well as replaced and
are relatively
mexpensive.

7. Jack Hammers
• These are hand air
operated percussion
type drills.
• They are used for
drilling holes, these
hammers are also
known as ‘Sinkers’.

8. • Drifter :
These are similar in operations to jack
hammers. They are used deeper holes weigh from 35 kg
to 120 kg. Because of higher weight they are mounted for
horizontal.
• Diamond Drills :
Diamond drills are used primarily for
exploration drilling, where cores are desired for the
purpose of studying the rock structure.

9. Wagon Drills
• Wagon drills consist of
drifters mounted on
masts which are
mounted on wheels to
provide portability. Up
to 30 ft or more in
depth.
• They may be used to
drill at any angle from
down to slightly above
horizontal.

10. • Carbide inset bit :
The
carbide insert bit is a
detachable bit whose
cutting edge consist of
tungsten carbide
embedded in a softer
steel base.
Depth of holes, 12 ft.

11. Selection of Drilling Method
 Hardness of the rock.
 Depth of Bore holes.
 Nature of terrain.
 Texture of rock.
 Availability of water.
 Size of project.

12. Selection of Drilling Equipments
 For small diameter shallow bore holes, use jack
hammers.
 For upto 8 cm dia. Bore holes use diamond drills.
 Upto 15 cm dia. And 15 m deep hole use track
mounted, rotary percussion or piston drills.
 For 15 cm to 30 cm dia. Holes for 15 m to 90 m to
depth, use blast hole or rotary drills.
 For bores upto 8 cm dia. Use diamond drills.
 For very large cores, use short drills.

13. Selection of Drilling Pattern
 Type of rock
 Quantity of explosive used
 Type of drill used
 Rapidity of explosive used
 Size of drill used
 Depth of hole to be drilled
 Amount of stemming

14. Blasting
• Rock blasting is
resorted when rock has
to be loosened so that
the entire rock or part
of the rock may be
removed.
• The geological
formation influences
the type of equipment
and the drilling pattern.

15. Methods of Blasting
 Controlled and uncontrolled.
 Primary and secondary.
 Single shot and multiple shot.
 Electrical and non-electrical.

16. Terms used for Blasting
 Dynamite
 Safety fuse
 Blasting cap
 Prime line
 Blast hole
 Primer
 Stemming
 Prime det
 Detonator
 Trunk line

17. Explosive used for blasting
 Dynamite
 Ammonium nitrate
 Sturry
 ANFO
 Rapid detonating explosive (RDX)

18. Precaution in Blasting
• Failure of explosion
• Line of Least Resistance
• Needle and tamper
• Notice of blasting
• Retreat distance
• Seepage of water
• Skilled supervision
• Precautions during transportation
• Precautions during firing

19. Thank You