SVY2302 Mine surveying Assignment 1

Assignment 1

The following table provides an indicative relationship between the course objectives and course assessments. The table is for the benefit of the students and should be used as a Guide only.

Blasting and Borehole Surveying Problems

Value: 20% - 200 marks

Special Instructions: Marks will be awarded for neatness and presentation (e.g. diagrams, setting out, explanatory comments) as well as for method and accuracy. Note: Scans of hand written assignments will not be accepted.

Students need show all calculation steps. It is acceptable to use calculator close program in the calculations.

Question 1 (100 marks)

At the Bandar open cut coal mine, you as Surveyor in charge have been assigned the job of designing the next blast pattern in strip 37. The bench is 65 metres wide and the direction of the strip is 80°32'46".

The block to be blasted is one hundred and fifty metres long (150m) and sixty-five metres wide (65m). The top eight (8) metres of overburden is stripped off with a Cat D11 N dozer and a fleet of Cat 657E scrapers in a pre-stripping operation.

The natural surface and the coal seam are both known to have regular and consistent grades.

The Mine Geologist has supplied you with co-ordinate values and depths to coal of two boreholes in the vicinity.

*TOC = top of the coal seam

From your own surveys you also have the following co-ordinate values for the south west corner of the block to be blasted.

You are required to calculate:

1. The true dip and strike of the Natural surfaces (30 marks)
2. The true dip and strike of the Top of Coal surface (30 marks)
3. The volume of sandstone to be blasted if the batters are deemed to be vertical (40 marks)

Hint: you might follow the following procedure:

1. Calculate the direction and rate of dip of the natural surface, then the necessary RLs.
2. Calculate the direction and rate of dip of the Top of Coal, then the necessary RLs.
3. Take notice of the pre-strip
4. Calculate the volume of overburden to be removed to expose the coal within the block area.

Question 2 (40 marks)

The remaining overburden is composed of medium strength sandstone that has to be blasted. An Atlas Copco drill with a drill bit diameter of 127 mm will be used to drill the blast holes.

As the surveyor, you have been asked to design the blast pattern for above strip in Question 1.

26. Assume the average depth of blast hole is 5m, calculate the Burden and Spacing of the proposed blasting pattern (20 marks)
27. Calculate the total quantity of explosives required for the blast using

ANFO (1000kg/m³) (15 marks)

1. Check to ensure that the amount of explosive required can be adequately accommodated in the hole, allowing sufficient room for stemming at the

top of hole (5 marks)

Question 3 (60 marks)

Measurements were made during a diamond drill pickup survey, including to a staff inserted in the borehole 2905N. The observations are shown below. The instrument reads 0° at the zenith.

At IS11 to the end of the staff

Using the information gathered, calculate:

1. the collar co-ordinates of the borehole 2905N (45 marks)
2. the dip of the borehole 2905N (10 marks)
3. the direction of the borehole 2905N (5 marks)