Posted: September 13th, 2017

Drilling and Blasting of Rock

Paper, Order, or Assignment Requirements

there are two design project need to be done within 6 pages and the third one need to be complete within 3 or 4 pages

Design a coal overburden throw/cast blast for the following situation:

1. a) Blast length 900 m
2. b) Blasted bench width 100 m
3. c) Bench height 20 m
4. d) Overburden of shale/siltstone/sandy shale, average density 2.5 tonnes/m3
5. e) Standoff distance 1.5 m
6. f) Wet holes
7. g) Hole diameter 250 mm

Design the blast pattern, select initiation system, detail initiation sequence.

(2)

Students are to undertake a tunnel blast design for the following conditions:

• Tunnel is 5.5m wide by 5.5.m high
• Rock is a sandstone with a UCS of 400 MPa
• Drill hole diameter is 51 mm, hole length is 4m
• The cut is to contain 2 relief holes of 75mm diameter
• Dry conditions are anticipated, ANFO to be used with a density of 800 kg/m3 and a powder factor of 0.6 kg/m3
• Nonel detonators are to be used

Students are to determine:

1. The design of the cut, including burden and spacing for each element of the cut.
2. Burden and spacing of the easer, perimeter and lifer holes
3. Stemming length required
4. Method of hole priming
5. Firing sequence timings for the holes
6. Explosive utilisation

Results should be presented in a report format, including diagram s as required and details of calculations undertaken.

(3)

Work Site Report:

For the site at which you work compile a report on the production drilling and blasting operations at your site. Points to include within your report include:

1. The main methods of production drilling and blasting at the mine including machinery details.
2. Production drilling geometry including hole sizes, drill patterns, etc.
3. Types of explosives and primers
4. Details of initiation systems and methods
5. Performance in terms of powder factors, costs and general comments on efficiencies
6. General observations on drilling and blasting

As a guide your report should be typed and be 5  pages of A4 excluding diagrams and appendices. To complete the report brief sections on location, geology, etc. can be included but please do not over pad.